JP2022127061A - controller and robot - Google Patents

Abstract

[Problem] To provide a control device and the like that suppresses unintended fluctuations in the position of a base of a second robot arm supported by a first robot arm. [Solution] A control device controls a first robot arm having a link that supports a second robot arm and a joint. The control device includes a first estimation unit that estimates the movement of the joint when the first robot arm is caused to perform a target movement, a second estimation unit that estimates a force that the link will receive from the second robot arm when the second robot arm is caused to perform a target movement, a third estimation unit that estimates the force that the link will receive based on the estimated movement of the joint and the estimated force, a fourth estimation unit that estimates the amount of deformation of at least one of the link and the joint based on the force that the link receives, and a correction command unit that commands the first robot arm to perform an operation to compensate for the estimated amount of deformation. [Selected Figure] Figure 1

Description

The present disclosure relates to control devices and robots.

Conventionally, there is a robot arm mounted on a mobile device. For example, Patent Literature 1 discloses an industrial robot device that includes an articulated industrial robot and a moving device that moves the industrial robot. The moving device has a horizontal two-joint link mechanism composed of two links, and is fixed to the installation surface. An industrial robot is attached to the distal end of the distal link.

JP-A-1-281891

In the industrial robot device of Patent Document 1, when the industrial robot operates, the center of gravity of the industrial robot changes, and the moment given to the link of the moving device by the industrial robot may change. For example, when an industrial robot grips a workpiece, the loads and moments that the industrial robot applies to the links of the moving device can fluctuate. Such load and moment variations can cause deformations, such as deflection, in the links and joints of the moving device. Deformation of the links and joints changes the position of the industrial robot, and this positional change causes the industrial robot to vibrate. This can reduce the accuracy of the industrial robot's work.

An object of the present disclosure is to provide a control device and a robot that suppress unintended variations in the position of the base of a second robot arm supported by a first robot arm.

A control device according to an aspect of the present disclosure is a control device for a first robot arm having at least two links that support a second robot arm and at least one joint that interconnects the at least two links. to acquire a first motion command for causing the first robot arm to perform a first target motion, which is a target motion, and to obtain a motion command for the at least one joint when the first robot arm moves according to the first motion command. A first estimating unit for estimating a motion, and a second motion command for causing the second robot arm to perform a second target motion that is a target motion, and the second robot arm operates according to the second motion command. a second estimator for estimating a force applied from the second robot arm to a connecting portion between the second robot arm and the link; and an operation of the at least one joint estimated by the first estimator. , a third estimating unit that estimates the force received by the link based on the force estimated by the second estimating unit; a deformation amount of the link based on the force estimated by the third estimating unit; a fourth estimator for estimating at least one of a deformation amount of at least one joint; and moving the connection portion according to the first target motion based on the deformation amount estimated by the fourth estimator. a correction command unit that generates a correction command for the first motion command for compensating for the deformation amount, and commands the correction command to the first robot arm.

According to the technology of the present disclosure, it is possible to suppress unintended variation in the position of the base of the second robot arm supported by the first robot arm.

1 is a side view showing an example of a configuration of a robot according to an embodiment; FIG. 1 is a side view modeling an example of a configuration of a robot according to an embodiment; FIG. 1 is a block diagram showing an example of a hardware configuration of a control device according to an embodiment; FIG. 1 is a block diagram showing an example of a functional configuration of a control device according to an embodiment; FIG. 3 is a flow chart showing an example of the operation of the control device according to the embodiment; The side view which modeled the structure of the robot based on the modification 1. The side view which modeled the structure of the robot based on the modification 2.

(Embodiment)
Embodiments of the present disclosure will be described below with reference to the drawings. It should be noted that the embodiments described below are all comprehensive or specific examples. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in independent claims representing the highest concept will be described as arbitrary constituent elements. Also, each figure in the accompanying drawings is a schematic diagram and is not necessarily strictly illustrated. Furthermore, in each drawing, substantially the same components are denoted by the same reference numerals, and redundant description may be omitted or simplified. Also, in the specification and claims, "device" may mean not only one device, but also a system of multiple devices.

[Robot configuration]
A configuration of a robot 1 according to an embodiment will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is a side view showing an example of the configuration of the robot 1 according to the embodiment. FIG. 2 is a side view modeling an example of the configuration of the robot 1 according to the embodiment.

A robot 1 according to an embodiment includes a first robot arm 100 , a second robot arm 200 and a control device 300 . A first robot arm 100 is fixed to a support surface S and supports a second robot arm 200 . The first robotic arm 100 has at least one joint and at least two links, and the second robotic arm 200 has at least one joint and at least one link.

Although not limited to this, in the present embodiment, the first robot arm 100 includes two joints JTA1 and JTA2, three links 101-103, and drivers MA1 and MA2 for the joints JTA1 and JTA2. The second robot arm 200 includes six joints JTB1-JTB6, seven links 201-207, and drive devices MB1-MB6 for the joints JTB1-JTB6, respectively. The second robot arm 200 is a vertical articulated robot arm, but may be any type of robot arm. For example, the second robotic arm 200 may be a horizontal articulated, polar, cylindrical, rectangular, or other type of robotic arm. Also, the number of links of the second robot arm 200 is not limited to seven, and may be six or less or eight or more. It may be one or less or seven or more.

For the first robot arm 100 , the link 103 is located at the base of the first robot arm 100 and fixed to the support surface S. Although not limited to this, in the present embodiment, link 103 has a trapezoidal shape and functions as a base for links 101 and 102 . Link 102 is located at the tip of first robot arm 100 and link 101 is located between links 102 and 103 . Link 103 is an example of a proximal link.

The joint JTA1 is a rotational joint with one degree of freedom, and connects one end of the columnar link 101 to the link 103 so as to be rotatable about the first axis S1. The joint JTA2 is a rotational joint with one degree of freedom, and connects one end of the columnar link 102 to the other end of the link 101 so as to be rotatable about the second axis S2. A second robot arm 200 is attached to the other end of the link 102 . Therefore, links 101 and 102 are movable by joints JTA1 and JTA2.

Although not limited to this, in the present embodiment, the first axis S1 extends in a direction along the support surface S, for example, the horizontal direction, and the second axis S2 extends in a direction perpendicular to the support surface S, for example, the vertical direction. extends to The link 101 can rotate in a direction along a plane perpendicular to the support surface S, and the link 102 can rotate in a direction along the support surface S. The directions of the first axis S1 and the second axis S2 may be any directions, and may be different or the same. The first axis S1 and the second axis S2 are also the joint axes of the joints JTA1 and JTA2, respectively.

Drives MA1 and MA2 are configured to rotationally drive joints JTA1 and JTA2, respectively. Drives MA1 and MA2 each include an electric motor (not shown) as a drive source and a speed reducer (not shown). The speed reducers of the drives MA1 and MA2 respectively reduce the rotational speed of the rotational driving force of the respective electric motors and increase the rotational driving force for transmission to the joints JTA1 and JTA2. In this embodiment, the electric motor is a servomotor.

In the present specification and claims, the terms "horizontal direction" and "vertical direction" respectively refer to the "horizontal direction" and the "vertical direction" when the robot 1 is placed on a horizontal support surface S. means. Furthermore, "upward" means an upward direction perpendicular to the support surface S in the same case, i.e. vertically upward, and "downward" means downward perpendicular to the support surface S in the same case. direction, that is, the vertically downward direction. Further, as used herein and in the claims, "vertical", "perpendicular", "horizontal" and "parallel" are respectively completely vertical, vertical, horizontal or parallel, and completely vertical, vertical, It may include cases that can be considered substantially vertical, vertical, horizontal or parallel, including near horizontal or parallel.

For the second robotic arm 200 , the link 207 is located at the base of the second robotic arm 200 and fixed to the top surface of the link 102 . Link 207 is located above first robot arm 100 . Interface 110 between link 207 and link 102 is an example of a connecting portion of robot arms 100 and 200 . Although not limited to this, the center point 110A of the interface 110 is the reference point of the robot arms 100 and 200 in this embodiment. Hereinafter, the “interface 110” may be expressed as the “connection portion 110”, and the “center point 110A” may be expressed as the “reference point 110A”.

Although not limited to this, in the present embodiment, link 207 has a trapezoidal shape and functions as a base for links 201-206. Link 206 is located at the distal end of second robot arm 200, and links 201-205 are arranged in this order from link 207 to link 206, between links 206 and 207. FIG. An end effector E capable of applying an action to the work object W is attached to the tip of the link 206 . In this embodiment, the end effector E is configured to be able to grip the object W, although not limited to this.

All of the joints JTB1 to JTB6 are rotary joints with one degree of freedom that are rotatable about one axis. Joint JTB1 rotatably connects link 201 to link 207 . Joint JTB2 rotatably connects link 202 to link 201 . Joint JTB3 rotatably connects link 203 to link 202 . Joint JTB4 rotatably connects link 204 to link 203 . Joint JTB5 rotatably connects link 205 to link 204 . Joint JTB6 rotatably connects link 206 to link 205 .

The drive devices MB1-MB6 are configured to rotationally drive the joints JTB1-JTB6, respectively. Each of the driving devices MB1 to MB6 includes an electric motor (not shown) as a drive source and a speed reducer (not shown). In this embodiment, the electric motor is a servomotor.

Although not limited to this, in the present embodiment, the control device 300 is configured to control the motion of the robot 1 as a whole. The control device 300 includes an information processing device 300A and a robot controller 300B. Robotic controller 300B is configured to control the motion of robotic arms 100 and 200 . The information processing device 300A is configured to perform arithmetic processing related to motion control of the robot arms 100 and 200 .

The information processing device 300A and the robot controller 300B include computer devices. Although the configuration of the information processing device 300A is not particularly limited, for example, the information processing device 300A may include electronic circuit boards, electronic control units, microcomputers, personal computers, workstations, smart devices such as smartphones and tablets, and other electronic devices. etc. The robot controller 300B may include electrical circuitry for controlling the power supplied to the robot arms 100 and 200, and the like.

[Hardware configuration of control device]
A hardware configuration of the control device 300 according to the embodiment will be described with reference to FIG. FIG. 3 is a block diagram showing an example of the hardware configuration of the control device 300 according to the embodiment. The information processing device 300A includes a processor 301A, a memory 302A, a storage 303A, and an input/output I/F (interface) 304A as constituent elements. Each component of the information processing device 300A is interconnected by a bus 310A, but may be connected by any other wired or wireless communication. Robot controller 300B includes a processor 301B, memory 302B, input/output I/F 304B, and drive I/Fs 305B and 306B as components. Robot controller 300B may include storage. Each component of robot controller 300B is interconnected by bus 310B, but may be connected by any other wired or wireless communication. Not all of the components included in each of the information processing device 300A and the robot controller 300B are essential.

The set of processor 301A and memory 302A and the set of processor 301B and memory 302B each constitute a calculator. The computing unit transmits and receives commands, information, data, and the like to and from other devices. The calculator inputs signals from various devices and outputs control signals to each controlled object.

Memories 302A and 302B respectively store programs executed by processors 301A and 301B, various fixed data, and the like. Memories 302A and 302B may comprise storage devices such as semiconductor memories such as volatile and non-volatile memories. Although not limited to this, in the present embodiment, the memories 302A and 302B include random access memory (RAM), which is volatile memory, and read-only memory (ROM), which is nonvolatile memory.

The storage 303A stores various data. The storage 303A may be composed of a storage device such as a semiconductor memory, a hard disk drive (HDD), or a solid state drive (SSD).

Both processors 301A and 301B together with RAM and ROM form a computer system. The computer system of the information processing device 300A may realize the functions of the information processing device 300A by executing the program recorded in the ROM using the RAM as a work area by the processor 301A. The computer system of the robot controller 300B may realize the functions of the robot controller 300B by the processor 301B using the RAM as a work area and executing the program recorded in the ROM.

Some or all of the functions of the information processing device 300A and the robot controller 300B may be realized by the above computer system, or may be realized by dedicated hardware circuits such as electronic circuits or integrated circuits. It may be implemented by a combination of hardware circuits. Each of the information processing device 300A and the robot controller 300B may be configured to execute each process by centralized control by a single device, or may be configured to execute each process by distributed control by cooperation of a plurality of devices. may be The information processing device 300A and the robot controller 300B may be configured to include at least part of each other's functions, or may be integrated.

Although not limited to this, for example, the processors 301A and 301B include a CPU (Central Processing Unit), MPU (Micro Processing Unit), GPU (Graphics Processing Unit), microprocessor, processor core ), multiprocessor, ASIC (Application-Specific Integrated Circuit), FPGA (Field Programmable Gate Array), etc., IC (Integrated Circuit) chip, LSI (Large Scale Integration), etc. Formed logic circuit or dedicated Each processing may be realized by a circuit. A plurality of processes may be implemented by one or more integrated circuits, or may be implemented by one integrated circuit.

The input/output I/F 304A of the information processing device 300A connects the information processing device 300A and the robot controller 300B to enable input/output of information, commands, data, and the like therebetween. The input/output I/F 304B of the robot controller 300B connects the robot controller 300B and the input/output I/F 304A of the information processing device 300A to enable input/output of information, commands, data, and the like therebetween.

The first drive I/F 305B connects the robot controller 300B and the first drive circuit 120 of the first robot arm 100 to enable transmission and reception of signals and the like between them. The first drive circuit 120 is configured to control power supplied to the drives MA1 and MA2 of the first robot arm 100 according to command values included in signals received from the robot controller 300B.

The second drive I/F 306B connects the robot controller 300B and the second drive circuit 220 of the second robot arm 200 to enable transmission and reception of signals and the like between them. The second drive circuit 220 is configured to control power supplied to the drive devices MB1-MB6 of the second robot arm 200 according to command values included in signals received from the robot controller 300B.

The robot controller 300B may be configured to servo-control the servo motors of the drives MA1, MA2 and MB1-MB6. The robot controller 300B receives from the drive circuits 120 and 220, as feedback information, the detected value of the rotation sensor provided in each servomotor and the command value of the current from the drive circuits 120 and 220 to each servomotor. The robot controller 300</b>B uses the feedback information to determine command values for driving each servomotor, and transmits the command values to the drive circuits 120 and 220 .

The robot controller 300B may be configured to coordinate the axis control of a plurality of servo motors. The robot controller 300B controls the servo motors of the drive devices MB1 to MB6 as robot axis control, which is part of the plurality of axis controls, and controls the drive device MA1 as external axis control, which is part of the plurality of axis controls. and may be configured to control the servo motors of MA2.

[Functional Configuration of Control Device]
A functional configuration of the control device 300 according to the embodiment will be described with reference to FIG. FIG. 4 is a block diagram showing an example of the functional configuration of the control device 300 according to the embodiment. The information processing device 300A includes a first motion commanding unit 401, a second motion commanding unit 402, a first estimating unit 403, a second estimating unit 404, a third estimating unit 405, a fourth estimating unit 406, First position estimator 407, second position estimator 408, inertial element estimator 409, inertial force estimator 410, correction command unit 411, and storage units 421-423 are included as functional components. The functions of the functional components other than the storage units 421-423 are implemented by the processor 301A or the like, and the functions of the storage units 421-423 are implemented by storage devices such as the memory 302A and/or the storage 303A. The functions of the storage units 421 to 423 may be implemented by separate storage devices, or at least two of the functions of the storage units 421 to 423 may be implemented by one storage device. Not all of the above functional building blocks are essential.

The robot controller 300B includes a first drive command section 501 and a second drive command section 502 as functional components. The functions of the drive command units 501 and 502 are implemented by the processor 301B or the like. Not all of the above functional building blocks are essential.

The storage units 421 to 423 store various information, data, etc., and enable reading of the stored information, data, etc. FIG. For example, the first storage unit 421 stores control programs for the robot arms 100 and 200 . Although not limited to this, in the present embodiment, the control device 300 is configured to cause the robot arms 100 and 200 to operate autonomously according to the control program, that is, to cause the robot arms 100 and 200 to operate automatically. The first storage unit 421 may store target motion data such as teaching data for causing the robot arms 100 and 200 to operate autonomously. Note that the control device 300 may be configured to operate the robot arms 100 and 200 in accordance with an operation command received from an operation device (not shown), that is, to manually operate the robot arms 100 and 200 .

For example, the second storage unit 422 stores information on the first robot arm 100 . Information on the first robot arm 100 includes information on the links 101 to 103 and the joints JTA1 and JTA2. The information on the links 101 to 103 may include information such as the mass, size, shape, center of gravity position, moment of inertia, rigidity, and joint connection position of each of the links 101 to 103 . The stiffness of the link may include bending stiffness and torsional stiffness of the link. The information on the joints JTA1 and JTA2 may include information such as the mass, size, shape, center of gravity position, moment of inertia, rigidity, position and direction of the central axis of rotation, and connection position with the link of each of the joints JTA1 and JTA2. The stiffness of the joint may include the stiffness of the members forming the joint, the stiffness of the rotating portion of the joint, the stiffness of the speed reducer of the joint, and the like.

The information on the links 101 to 103 may be a virtual model reflecting the information on the links 101 to 103, and the information on the joints JTA1 and JTA2 is a virtual model reflecting the information on the joints JTA1 and JTA2. model. For example, the virtual model may be a three-dimensional model such as a three-dimensional CAD (Computer-Aided Design) model.

For example, the third storage unit 423 stores information on the second robot arm 200 . Information on the second robot arm 200 includes information on the links 201 to 207 and the joints JTB1 to JTB6. Further, the information of the second robot arm 200 can include information of the end effector E attached to the second robot arm 200, information of the object W such as a workpiece held by the end effector E, and the like. The information on the links 201 to 207 may include information such as the mass, size, shape, center of gravity position, moment of inertia, and joint connection position of each of the links 201 to 207 . The information on the joints JTB1 to JTB6 may include information such as the mass, size, shape, center of gravity position, moment of inertia, position and direction of the central axis of rotation, and connection position with the link of each of the joints JTB1 to JTB6. The information of the end effector E may include information such as its mass, dimensions, shape, center of gravity position, moment of inertia, connection position with the link 206, and the like. Information on the object W may include information such as its mass, size, shape, center of gravity position, and posture when it is held. The information of the links 201-207, the joints JTB1-JTB6, the end effector E, and the object W may be virtual models reflecting the above information. For example, the virtual model may be a three-dimensional model such as a three-dimensional CAD model.

The first motion command unit 401 causes the first robot arm 100 to perform a target motion according to first target motion data, which is target motion data of the first robot arm 100 stored in the first storage unit 421 . A command (hereinafter also referred to as a “first operation command”) is generated. The first target motion data is data for operating the first robot arm 100 according to the control program. For example, the first motion commanding unit 401 sets the target position and the target orientation of the connecting portion 110 for moving the connecting portion 110 according to the first target motion data of the first robot arm 100 stored in the second storage unit 422 . Compute using information. The target position and target orientation may be the three-dimensional position of the reference point 110A and the three-dimensional orientation of the interface of the connection portion 110. FIG.

Further, the first motion command unit 401 sets the target rotation direction and target rotation amount of the joints JTA1 and JTA2 for moving the connection portion 110 to the target position and target orientation, and the target rotation amount is stored in the second storage unit 422. The information on the arm 100 is used for calculation. That is, the first motion command unit 401 calculates the target rotational positions of the joints JTA1 and JTA2. The first motion command unit 401 may be configured to use the first target motion data and the information of the first robot arm 100 to calculate the target rotational positions of the joints JTA1 and JTA2. The first motion command unit 401 generates a first motion command including the target rotational positions of the joints JTA1 and JTA2. In the case of manual operation, the first motion command unit 401 issues a first motion command for causing the first robot arm 100 to execute a target motion in accordance with an operation command received from an operation device (not shown) in the same manner as described above. Generate.

The second motion command unit 402 causes the second robot arm 200 to perform a target motion according to the second target motion data, which is the target motion data of the second robot arm 200 stored in the first storage unit 421. A command (hereinafter also referred to as a “second operation command”) is generated. The second target motion data is data for operating the second robot arm 200 according to the control program. For example, the second motion command unit 402 obtains the target position and target orientation of the link 206 for moving the link 206 according to the second target motion data, and the information of the second robot arm 200 stored in the third storage unit 423. Calculate using The target position and target orientation may be the three-dimensional position and three-dimensional orientation of the tip of the link 206 .

Further, the second motion command unit 402 sets the target rotation direction and the target rotation amount of the joints JTB1 to JTB6 for moving the link 206 to the target position and target orientation. 200 information is used for calculation. That is, the second motion command unit 402 calculates the target rotational positions of the joints JTB1 to JTB6. The second motion command unit 402 may be configured to use the second target motion data and the information of the second robot arm 200 to calculate target rotational positions of the joints JTB1 to JTB6. The second motion command unit 402 generates a second motion command including target rotational positions of the joints JTB1 to JTB6. In the case of manual operation, the second motion command unit 402 issues a second motion command for causing the second robot arm 200 to execute a target motion in accordance with an operation command received from an operation device (not shown) in the same manner as described above. Generate.

The first estimation unit 403 acquires the first motion command from the first motion command unit 401, and estimates motions of the joints JTA1 and JTA2 when the first robot arm 100 operates according to the first motion command. For example, the first estimation unit 403 calculates an estimated rotational position, which is an estimated value of the rotational positions of the joints JTA1 and JTA2, as motions of the joints JTA1 and JTA2. The estimated rotational positions of the joints JTA1 and JTA2 include estimated values of the direction and amount of rotation of the joints JTA1 and JTA2. The estimated rotational positions of the joints JTA1 and JTA2 correspond to the target rotational positions of the joints JTA1 and JTA2 included in the first motion command. Further, the first estimator 403 calculates an estimated rotational speed, which is an estimated rotational speed of the joints JTA1 and JTA2, based on the estimated rotational positions of the joints JTA1 and JTA2.

The second estimating unit 404 acquires the second motion command from the second motion commanding unit 402, and when the second robot arm 200 moves according to the second motion command, the connection part 110 moves toward the second robot arm at the reference point 110A. Estimate the force received from 200. Although not limited to this, in the present embodiment, second estimation section 404 estimates the force using a reference coordinate system having reference point 110A as origin O.

The reference coordinate system may be a coordinate system having the origin O at the reference point 110A. Although not limited to this, in the present embodiment, the reference coordinate system includes, as shown in FIG. It is defined by a Z-axis extending from 110A in a direction perpendicular to the interface of the connecting portion 110 and perpendicular to the X-axis and the Y-axis. The Z-axis positive direction is the direction from the link 207 to the link 102 . Alternatively, for example, the reference coordinate system is defined by an X-axis and a Y-axis extending horizontally from the reference point 110A and orthogonal to each other, and a Z-axis extending vertically downward from the reference point 110A and orthogonal to the X-axis and the Y-axis. may be defined. The vertically downward direction may be the direction of gravity, and the horizontal direction may be the direction perpendicular to the direction of gravity.

For example, the force may include the load of the second robot arm 200 and the moment the second robot arm 200 develops at the connection portion 110 . For example, the second estimation unit 404 estimates the positions and orientations of the links 201 to 207 and the joints JTB1 to JTB6 when the second robot arm 200 operates according to the second motion command, and stores the estimation result and the third storage unit 423. The force may be estimated using stored information of the second robot arm 200 .

The load of the second robotic arm 200 may include the mass of the second robotic arm 200 itself, the mass of the end effector E, and the mass of the object W held by the end effector E. The moment of the second robot arm 200 may include the moment generated at the connecting portion 110 by the second robot arm 200 itself, the end effector E, and the object W. FIG. The second estimation unit 404 uses the information of the second robot arm 200 stored in the third storage unit 423 and the target rotational positions of the joints JTB1 to JTB6 included in the second motion command to determine the position of the second robot arm 200. Calculate loads and moments. A second estimator 404 represents the loads and moments of the second robot arm 200 using a reference coordinate system. Further, the second estimating unit 404 uses the information of the second robot arm 200 stored in the third storage unit 423 and the target rotational positions of the joints JTB1 to JTB6 included in the second motion command to determine the second robot arm 200 The moment of inertia of the entire 200 is calculated with reference to the reference coordinate system. The moment of inertia is the moment of inertia with reference to the origin O of the reference coordinate system.

The third estimating unit 405 calculates the link motion based on the motions of the joints JTA1 and JTA2 estimated by the first estimating unit 403 and the force that the connecting part 110 receives from the second robot arm 200 estimated by the second estimating unit 404 . Estimate the forces that 101-103 receive. Although not limited to this, in the present embodiment, even if the trapezoidal link 103 receives a force via the link 101 and the joint JTA1, it hardly deforms such as deflection and is immovable. Unit 405 estimates the forces experienced by links 101 and 102 .

For example, the third estimating unit 405 estimates the inertial force generated in the links 101 and 102 and the joint 110 and the force received from the second robot arm 200, the forces received by the links 101 and 102 are estimated.

A fourth estimation unit 406 estimates at least one of the deformation amounts of the links 101 and 102 and the deformation amounts of the joints JTA1 and JTA2 based on the forces received by the links 101 and 102 estimated by the third estimation unit 405. . In this embodiment, the fourth estimation unit 406 estimates both the deformation amounts of the links 101 and 102 and the deformation amounts of the joints JTA1 and JTA2.

The first position estimation unit 407 estimates the positions and orientations of the links 101 and 102 and the joints JTA1 and JTA2. The first position estimation unit 407 estimates the three-dimensional positions and three-dimensional orientations of the links 101 and 102 and the joints JTA1 and JTA2, respectively, using the reference coordinate system. For example, the first position estimation unit 407 uses the estimated rotational positions of the joints JTA1 and JTA2 estimated by the first estimation unit 403 and the information of the first robot arm 100 stored in the second storage unit 422 to The estimated positions and orientations of the links 101 and 102 and the joints JTA1 and JTA2 at the estimated rotational positions are calculated. The first position estimator 407 calculates the moment of inertia of the links 101 and 102 based on the reference coordinate system based on the estimated positions and orientations of the links 101 and 102 and the joints JTA1 and JTA2. The moment of inertia is the moment of inertia with reference to the origin O of the reference coordinate system.

A second position estimator 408 estimates the position of the connecting portion 110 . Specifically, second position estimation section 408 estimates the three-dimensional position of reference point 110A of connection portion 110 and the three-dimensional orientation of the interface of connection portion 110 using the reference coordinate system. For example, the first position estimation unit 407 uses the estimated rotational positions of the joints JTA1 and JTA2 estimated by the first estimation unit 403 and the information of the first robot arm 100 stored in the second storage unit 422 to An estimated position and an estimated orientation of the connection portion 110 at the estimated rotational position may be calculated. The second position estimator 408 calculates the estimated position and orientation of the connecting portion 110 using the estimated positions and orientations of the links 101 and 102 and the joints JTA1 and JTA2 estimated by the first position estimator 407. may The second position estimation unit 408 acquires the target position and target orientation of the joint 110 corresponding to the target rotational positions of the joints JTA1 and JTA2 from the first motion command unit 401, and converts the target position and target orientation into the reference coordinate system. , and may be used as the estimated position and the estimated orientation.

The inertial element estimator 409 estimates the inertial characteristics of the links 101 to 103 and the inertial characteristics of the second robot arm 200 . Although not limited to this, in the present embodiment, even if the link 103 receives a force via the link 101 and the joint JTA1, the link 103 hardly undergoes deformation such as deflection and is immobile. Estimate the inertial characteristics of links 101 and 102 . The inertial characteristics of links 101 and 102 include the moment of inertia and mass of links 101 and 102 as factors. The inertial characteristics of the second robot arm 200 include the moment of inertia and the mass of the second robot arm 200 as factors.

Based on the motions of the joints JTA1 and JTA2 estimated by the first estimating unit 403, the inertial force estimating unit 410 calculates the inertial forces generated in the links 101 to 103 by the motions of the joints JTA1 and JTA2 (hereinafter referred to as “joint-induced forces”). (also referred to as "inertial force"). Although not limited to this, in the present embodiment, even if the link 103 receives a force via the link 101 and the joint JTA1, the link 103 hardly undergoes deformation such as deflection and is immobile. A joint-induced inertial force generated in the links 101 and 102 is estimated.

Specifically, the inertial force estimation unit 410 calculates the inertial characteristics of the links 101 and 102, the inertial characteristics of the second robot arm 200, the acceleration of the joints JTA1 and JTA2, and the joint screws of the joints JTA1 and JTA2. is used to estimate the joint-induced inertial forces generated in the links 101 and 102. The joint screws of joints JTA1 and JTA2 are each a feature that indicates the state of that joint, including an element that indicates the orientation of that joint.

Based on the deformation amounts of the links 101 and 102 and/or the deformation amounts of the joints JTA1 and JTA2 estimated by the fourth estimator 406, the correction command unit 411 moves the connection portion 110 according to the first target motion. A correction command is generated for the first motion command to compensate for the amount. The correction command section 411 outputs the correction command to the first robot arm 100 , more specifically, to the first drive command section 501 . Although not limited to this, in the present embodiment, the correction command unit 411 corrects the first motion command to compensate for the deformation amount, and generates the corrected first motion command as the correction command. When the first operation command is not corrected, the correction command unit 411 outputs the uncorrected first operation command to the first drive command unit 501 as a correction command. Further, the correction command section 411 outputs a second motion command to the second robot arm 200 , more specifically, to the second drive command section 502 .

The first drive command unit 501 generates a drive command for causing the drive devices MA1 and MA2 to drive the joints JTA1 and JTA2 to the target rotational positions of the joints JTA1 and JTA2 included in the correction command. Output. The drive commands include current command values for the servo motors of the drives MA1 and MA2. A first drive command unit 501 generates a drive command using feedback information of the servomotor.

The second drive command unit 502 generates a drive command for causing the drive devices MB1 to MB6 to drive the joints JTB1 to JTB6 to the target rotational positions of the joints JTB1 to JTB6 included in the second motion command. Output to MB6. The drive commands include current command values for the servo motors of the drive devices MB1 to MB6. A second drive command unit 502 generates a drive command using feedback information of the servomotor.

[Operation of the control device]
The operation of the control device 300 will be described with reference to FIG. FIG. 5 is a flow chart showing an example of the operation of the control device 300 according to the embodiment. First, in the information processing device 300A, the first motion command unit 401 generates a first motion command for moving the first robot arm 100 according to the first target motion data stored in the first storage unit 421 (step S101).

Next, the second motion command unit 402 generates a second motion command for moving the second robot arm 200 according to the second target motion data stored in the first storage unit 421 (step S102).

Next, the first estimation unit 403 estimates motions of the joints JTA1 and JTA2 when the first robot arm 100 operates according to the first motion command (step S103). The first estimation unit 403 calculates the estimated rotational positions and the estimated rotational velocities of the joints JTA1 and JTA2 as the motion to be estimated.

Next, the first position estimation unit 407 estimates the positions and orientations of the links 101 and 102 and the joints JTA1 and JTA2 when the first robot arm 100 operates according to the first motion command (step S104). For example, the first position estimation unit 407 uses the estimated rotational positions of the joints JTA1 and JTA2 estimated by the first estimation unit 403 and the information of the first robot arm 100 stored in the second storage unit 422 to The estimated positions and orientations of the links 101 and 102 and the joints JTA1 and JTA2 may be calculated.

For example, the first position estimator 407 calculates the estimated positions of the centers of gravity of the links 101 and 102 as the estimated positions of the links 101 and 102 based on the reference coordinate system. For example, the first position estimator 407 calculates an estimated position vector γ _g1о of the center of gravity of the first link 101 in the reference coordinate system and an estimated position vector γ _g2о of the center of gravity of the second link 102 in the reference coordinate system. . Hereinafter, the position vector of the i-th link with reference to the reference point 110A, which is the origin O of the reference coordinate system, is represented as "γ _gio ". The link number “i” increases from the proximal end to the distal end of the first robot arm 100 . Note that the first position estimator 407 may be configured to calculate estimated positions of other reference points set on the links 101 and 102 based on the reference coordinate system.

For example, the first position estimation unit 407 calculates the estimated position of the center of gravity of the joints JTA1 and JTA2 and the estimated orientation of the reference axis as the estimated positions and orientations of the joints JTA1 and JTA2 based on the reference coordinate system. For example, the first position estimator 407 calculates an estimated position vector γ 1 о of the center of gravity of the first joint JTA 1 in the reference coordinate system and an estimated position vector _γ 2 _о of the center of gravity of the second joint JTA 2 in the reference coordinate system. . In the following, the position vector of the j-th joint with reference to the origin O of the reference coordinate system is expressed as "γ _jо ". The joint number “j” increases from the proximal end to the distal end of the first robot arm 100 . Note that the first position estimation unit 407 may be configured to calculate estimated positions of other reference points set at the joints JTA1 and JTA2 based on the reference coordinate system.

For example, the first position estimating unit 407 uses the estimated orientation vector d1? of the first joint _JTA1 in the reference coordinate system and the estimated orientation vector d1? A direction vector _d2? is calculated. In the following, the direction vector of the j-th joint with reference to the origin O of the reference coordinate system is represented as "d _jo ". The direction vector _djo is a vector indicating the direction of the reference axis for the movement of the j-th joint. For example, if the j-th joint is a rotational joint, the direction vector _djo is the direction vector of the rotation center axis, which is the joint axis. When the j-th joint is a prismatic joint, the direction vector _djo is the direction vector of the axis in the prismatic direction that is the joint axis.

Furthermore, the first position estimation unit 407 uses the estimated positions of the links 101 and 102, the estimated positions and estimated orientations of the joints JTA1 and JTA2, and the information of the first robot arm 100 stored in the second storage unit 422 to , compute the moments of inertia _l10 and _l20 of the links 101 and 102 with respect to the origin O of the reference coordinate system. In the following, the moment of inertia of the i-th link with reference to the origin O of the reference coordinate system is expressed as "l _iO ".

Next, the second position estimator 408 estimates the position and orientation of the connecting portion 110 when the first robot arm 100 operates according to the first motion command (step S105). For example, the first position estimation unit 407 stores the estimated positions and orientations of the links 101 and 102 and the joints JTA1 and JTA2 estimated by the first position estimation unit 407, and the first robot arm stored in the second storage unit 422. 100 may be used to compute an estimated position and attitude of the connecting portion 110 .

A second position estimator 408 calculates the estimated position of the reference point 110A and the estimated orientation of the interface of the connection portion 110 based on the robot coordinate system. In other words, the second position estimator 408 calculates the estimated position and the estimated orientation of the reference coordinate system based on the robot coordinate system. The robot coordinate system is a coordinate system defined with the robot 1 as a reference. Although not limited to this, in the present embodiment, the origin Or of the robot coordinate system is set at the position of the link 103 on the support surface S, as shown in FIG. The Xr-axis and the Yr-axis extend along the support surface S from the origin Or and are orthogonal to each other. The Zr-axis extends upward perpendicularly to the support surface S from the origin Or and is perpendicular to the Xr-axis and the Yr-axis.

Next, the second estimator 404 estimates the force that the connecting portion 110 receives from the second robot arm 200 when the second robot arm 200 operates according to the second motion command (step S106). The force includes the load of the second robot arm 200 and the moment generated by the second robot arm 200 at the connecting portion 110 . For example, the second estimator 404 calculates the estimated positions and orientations of the links 201 to 207 and the joints JTB1 to JTB6 based on the reference coordinate system based on the target rotational positions of the joints JTB1 to JTB6 included in the second motion command. Calculate. Further, the second estimation unit 404 stores the estimated positions and orientations of the links 201 to 207 and the joints JTB1 to JTB6, the estimated position and orientation of the connecting portion 110 estimated by the second position estimation unit 408, and the third memory Using the information of the second robot arm 200 stored in the unit 423, the moment generated by the second robot arm 200 at the connecting portion 110 and the load of the second robot arm 200 are calculated with reference to the reference coordinate system.

Further, the second estimating unit 404 uses the estimated positions and orientations of the links 201 to 207 and the joints JTB1 to JTB6 and the information of the second robot arm 200 to estimate the center-of-gravity position of the second robot arm 200 as a whole. The position of the center of gravity and the estimated moment of inertia, which is the moment of inertia of the second robot arm 200 as a whole, are calculated. At this time, the second estimating unit 404 uses the center-of-gravity position and mass of the links 201-207, the center-of-gravity position and mass of the joints JTB1-JTB6, the center-of-gravity position and mass of the end effector E, and The center-of-gravity position and mass of the object W can be used.

Next, the inertial element estimator 409 estimates the inertial characteristics of each of the links 101 and 102 of the first robot arm 100 and the inertial characteristics of the entire second robot arm 200 (step S107). The inertial element estimating unit 409 uses the information of the first robot arm 100 stored in the second storage unit 422 and the information of the second robot arm 200 stored in the third storage unit 423 to determine the reference coordinate system. Calculate each inertial feature that

Hereinafter, the inertial characteristic of the i-th link is represented as "L _iO ", and the inertial characteristic of the second robot arm 200 as a whole is represented as "L _aO ". Inertial features "L _iO " and "L _aO " are referenced to the origin O of the reference coordinate system. The inertial feature L _iо is a 6×6 matrix representing the mass and moment of inertia of the i-th link. The inertial feature L _aо is a 6×6 matrix representing the mass and moment of inertia of the second robot arm 200 as a whole. The inertial element estimator 409 calculates inertial features L _{i о} and L a _о using Equations 1 and 2 below, respectively. The inertial features L i о and L a _{о shown in Equations 1 and 2 are also called inertial biners .}

In Equation 1, the element "m _i " is the mass of the i-th link and is a scalar. Element "l _iO " is a 3x3 matrix representing the moment of inertia of the i-th link. Element "E" is the identity matrix. The element "γ _giO " is the three-dimensional position vector of the center of gravity of the i-th link. [γ _giO ×] is a distortion-symmetric matrix representing the outer product of the position vectors γ _giO , and is also called the outer product matrix of the position vectors γ _giO .

In Equation 2, the element “m _a ” is the mass of the entire second robot arm 200 and is a scalar. The element “ _laO ” is a 3×3 matrix representing the moment of inertia of the second robot arm 200 as a whole. The element “γ _gaO ” is a three-dimensional position vector of the center of gravity of the second robot arm 200 as a whole. [γ _gaO ×] is the outer product of the position vectors γ _gaO expressed by a skew-symmetric matrix.

Next, based on the motions of the joints JTA1 and JTA2 estimated by the first estimating unit 403, the inertia force estimating unit 410 generates inertial forces (joint-induced inertia force) is estimated (step S108). The inertial force estimator 410 uses the estimated rotational positions of the joints JTA1 and JTA2 estimated by the first estimator 403 and the inertial features estimated by the inertial element estimator 409 to generate forces on the links 101 and 102. Calculate joint-induced inertial force.

Specifically, the inertial force estimator 410 calculates the joint screws of the joints JTA1 and JTA2. The joint screw of the j-th joint is represented as " _Mjo ". The inertial force estimator 410 calculates the estimated joint screw M1' of the first joint _JTA1 and the estimated joint screw M2' of the second joint _JTA2 with reference to the reference coordinate system. The joint screw _Mjo is represented by a 6-dimensional vector.

In this embodiment, both the joints JTA1 and JTA2 are rotary joints that are rotatable around one central axis of rotation. For example, the inertial force estimator 410 calculates the estimated joint screw _Mjo of the j-th joint as shown in Equation 3 below. In Equation 3, γ _jо ×d _jо represents the outer product of γ _jо and d _jо . The element “γ _jo ” is the estimated 3-dimensional position vector of the j-th joint, and the element “d _jo ” is the estimated 3-dimensional direction vector of the j-th joint. The estimated direction vector _djo of the j-th joint indicates the direction vector of the rotation center axis, which is the joint axis of the j-th joint.

Equation 3 above shows the joint screw of the j-th joint when the j-th joint is a rotary joint. can be done. For example, when the j-th joint is a prismatic joint, the joint screw of the j-th joint can be expressed as in Equation 4 below. When the j-th joint is a screw joint, the joint screw of the j-th joint can be expressed as Equation 5 below. In Equation 4, the element “d _jo ” indicates the direction vector of the axis in the translational direction, which is the joint axis of the j-th joint. In Equation 5, the element “d _jo ” indicates the direction vector of the rotation center axis of the screw rotation, which is the joint axis of the j-th joint, and the direction vector is also the direction vector of the axis in the advancing and retreating direction of the screw rotation. The screw joint is configured such that when the link connected to the screw joint rotates around the rotation center axis, the link moves forward and backward in the direction of the rotation center axis. The element "h" indicates the pitch of screw rotation, for example, the amount of movement of the link in the direction of the center axis of rotation per rotation of 1 radian.

Furthermore, inertial force estimation section 410 estimates the acceleration of joints JTA1 and JTA2. The acceleration is the acceleration generated by the joints JTA1 and JTA2 when the joints JTA1 and JTA2 move to the estimated rotation position. For example, the inertial force estimating unit 410 time-differentiates the estimated rotation speeds of the joints JTA1 and JTA2 estimated by the first estimating unit 403, thereby obtaining the estimated accelerations θ ₁ ″ and θ ₂ ^' of the joints JTA1 and JTA2 ^{. '} is calculated.

Inertial force estimator 410 uses inertial features L ₁ , L ₂ , and _La , joint _screws M 1 , M ₂ , and estimated accelerations θ ₁ ^'' and θ ₂ ^'' to calculate estimated acceleration θ ₁ ^'' and _{θ 2} ^'' to the i-th link are calculated based on the reference coordinate system. The joint-induced inertial force F _ijо represents the inertial force generated in the i-th link by the estimated acceleration θ _j ^″ of the j-th joint with respect to the origin O of the reference coordinate system. The joint-induced inertial force F _ijо includes three translational components and three rotational components, and is represented by a six-dimensional vector. The inertia force estimator 410 converts the joint-induced inertia forces F _{11 о} , F _{12 о} , F _{21 о} , and F _{22 о} generated in the links 101 and 102 by the estimated accelerations θ ₁ ^'' and θ ₂ ^'' into the following equations 6 to 9. Calculate as shown. The joint-induced inertial force F _ijо includes, as elements, the inertial characteristics of the link that moves due to the movement of the j-th joint and the inertial characteristics of the second robot arm 200 .

Next, the third estimating unit 405 estimates the force that the links 101 and 102 receive based on the joint-induced inertial force estimated by the inertial force estimating unit 410 and the force estimated by the second estimating unit 404 (step S109). The third estimating unit 405 uses the estimated inertial force _FaO of the second robot arm 200 as the force estimated by the second estimating unit 404 . The estimated inertial force _FaO may be an inertial force applied to the origin O by the second robot arm 200 with the origin O of the reference coordinate system as a reference. Although not limited to this, in the present embodiment, the load and moment of the second robot arm 200 estimated by the second estimator 404 are used as the estimated inertial force _FaO . The estimated inertial force F _aо includes load components in three directions and moment components in three directions, and is represented by a six-dimensional vector.

Third estimation unit 405 uses joint-induced inertia force F _ijо and estimated inertia force F _aо to calculate estimated inertia force _Fiо generated in the i-th link with reference to the origin O of the reference coordinate system. Calculate as the force received. The estimated inertial force F _iо includes three translational components and three rotational components, and is represented by a six-dimensional vector. The third estimator 405 calculates the estimated inertia forces F _{1 '} and F ₂ ' generated in the links 101 and 102 as shown in Equations 10 and 11 below.

Next, the fourth estimation unit 406 estimates the deformation amounts of the links 101 and 102 and the deformation amounts of the joints JTA1 and JTA2 based on the forces received by the links 101 and 102 estimated by the third estimation unit 405 (step S110 ).

The fourth estimation unit 406 uses the stiffness _kg1 and kg2 of the joints JTA1 and _JTA2 and the estimated inertial forces _F1о and _F2о included in the information about the first robot arm 100 stored in the second storage unit 422. to calculate the estimated deformation amounts of the joints JTA1 and JTA2. In this case, the fourth estimator 406 uses the estimated inertial forces F 1 and F ₂ and the joint screws M ₁ and M ₂ to calculate the estimated torques τ ₁ and τ ₂ acting on the joints _JTA1 and JTA2, respectively, as follows: It is calculated as shown in Equations 12 and 13 below. Hereinafter, the stiffness of the j-th joint is represented as "k _gj ", and the estimated torque of the j-th joint is represented as "τ _j ". The stiffness k _gj includes 3 translational and 3 rotational components and is represented by a 6-dimensional vector. The stiffness _kgj includes the spring constant of the speed reducer, which is the stiffness of the speed reducer of the j-th joint. The estimated torque τ _j is a scalar.

The operator “◯” in Equations 12 and 13 indicates a vector distribution operation. For example, a six-dimensional vector A includes a vector a1 including _a three-dimensional translational component and a vector _a2 including a three-dimensional rotational component, and a six-dimensional vector B is a three-dimensional translational component. When the vector b1 including the directional component and the vector b2 including the three-dimensional rotational direction component are included, the calculation of the vectors _A and _B using the operator "o" is as shown in the following equation 14. shown.

Furthermore, the fourth estimation unit 406 calculates the estimated deformation amount Δθ _j of the j-th joint by dividing the estimated torque τ _j by the stiffness k _gj . The fourth estimation unit 406 calculates estimated deformation amounts Δθ ₁ and Δθ ₂ of the joints JTA1 and JTA2, respectively, as shown in Equations 15 and 16 below. The estimated deformation amount Δθ _j can be a compensation amount for deformation at the j-th joint.

Further, the fourth estimating unit 406 calculates the compliances _CI1 ' and _CI2 ' of the links 101 and 102 included in the information about the first robot arm 100 stored in the second storage unit 422, and the estimated inertia forces F1 _' and F2 _' . is used to compute the estimated deformation amounts of the links 101 and 102 . In the following, the compliance of the i-th link is denoted as "C _Ii ". The compliance C _Iiо indicates the stiffness of the i-th link with reference to the origin O of the reference coordinate system, and is represented by a 6×6 matrix.

The fourth estimator 406 uses the estimated inertia forces _F1 and _F2 and the compliances C _I1 and C _I2 to calculate the estimated deformation amounts _Δ1 and _Δ2 of the links 101 and 102, respectively, using the following equations 17 and 2 Calculate as shown in 18. In the following, the estimated deformation amount of the i-th link is expressed as "Δ _iо ". The estimated deformation amount Δ _iо includes three translational direction components and three rotational direction components, and is represented by a six-dimensional vector with reference to the reference coordinate system.

Further, the fourth estimation unit 406 uses the estimated deformation amount _Δiо of the i-th link and the joint screw _Mjo of the j-th joint to convert the estimated deformation amount _∆iо of the i-th link into the estimated deformation amount of the j-th joint. may be converted. Let the vector δ _ti be the vector containing the three-dimensional translational component contained in the estimated deformation amount Δ i , and _{let the vector ν jо be} the vector containing the three-dimensional translational component contained in the joint screw _Mjo . The estimated deformation amount Δ i о of the i-th link can be converted into the estimated deformation amount _{ΔθL j} of the j-th joint as shown in Equation 19 below. The estimated deformation amount ΔθL _j can be a compensation amount for link deformation.

Next, based on the deformation amount estimated by the fourth estimation unit 406, the correction command unit 411 issues a correction command for the first motion command for compensating for the deformation amount so as to move the connecting portion 110 according to the first target motion. is generated (step S111). The correction command unit 411 associates the correction command and the second motion command, and transmits them to the robot controller 300B. The correction command unit 411 corrects the first motion command so that the position and orientation of the connecting portion 110 are set to the target position and target posture by compensating for the amount of deformation, and uses the first motion command after correction as the correction command. Send.

For example, the correction command unit 411 may correct the first motion command by adding the estimated deformation amount Δθ _j of the j-th joint to the target rotational position of the j-th joint included in the first motion command. The correction command unit 411 may correct the first motion command by adding the estimated deformation amount ΔθL _j of the j-th joint to the target rotational position of the j-th joint included in the first motion command. This compensates for the amount of deformation of both the links and the joints. In the present embodiment, since the j-th joint is a rotational joint having one degree of freedom, correction command section 411 sets one of the estimated deformation amount Δθ _j and the estimated deformation amount ΔθL _j to the j-th joint. It is added to the desired rotational position of joint j, but both may be added to the desired rotational position of joint j. If the j-th joint has two or more degrees of freedom, the correction command unit 411 may add both the estimated deformation amount Δθ _j and the estimated deformation amount ΔθL _j to the target rotation position of the j-th joint.

Next, in the robot controller 300B, the drive command units 501 and 502 generate drive commands and output them to the robot arms 100 and 200 (step S112). The first drive command section 501 generates a drive command according to the correction command and outputs it to the drive devices MA1 and MA2 of the first robot arm 100 . The second drive command section 502 generates a drive command according to the second motion command and outputs it to the drive devices MB1 to MB6 of the second robot arm 200. FIG. The drive command units 501 and 502 cooperate with each other to output the respective drive commands so as to synchronize the output timings of the respective drive commands. As a result, the robot arms 100 and 200 simultaneously execute their respective target motions, but due to the motions of the two robot arms 100 and 200, the position and orientation of the connecting portion 110 fluctuate from the target position and target posture. can be suppressed. Therefore, the second robot arm 200 can accurately perform the target motion on the object W to which the action is applied.

(Modification 1)
This modification differs from the embodiment in that the first robot arm 100A has only one joint. In the following, this modified example will be described with a focus on the points that are different from the embodiment, and the description of the points that are the same as the embodiment will be omitted as appropriate.

FIG. 6 is a side view modeling the configuration of the robot 1A according to Modification 1. As shown in FIG. As shown in FIG. 6, the robot 1A includes a second robot arm 200 and a first robot arm 100A similar to those of the embodiment. The first robot arm 100A includes links 101A and 102A and a joint JTAA1 that rotatably connects the links 101A and 102A. Although not limited to this, the first link 101A of this modification has the same configuration as the second link 102 of the embodiment, and the second link 102A of this modification has the third link 103 of the embodiment. has the same configuration as The first joint JTAA1 of this modification has the same configuration as the second joint JTA2 of the embodiment. The robot 1A includes a control device 300 including an information processing device 300A and a robot controller 300B similar to those of the embodiment. The information processing device 300A performs the same processing as in the embodiment, but performs calculations using a different arithmetic expression from the embodiment in the following points.

Inertia force estimator 410 uses Equation 20 below instead of Equations 6 to 9 of the embodiment to calculate the joint-induced inertia force generated in first link 101A by estimated acceleration θ ₁ ^″ of first joint JTAA1. Compute F _11о .

The third estimator 405 calculates the estimated inertial force F1 _? generated in the first link 101A using the following formula 21 instead of the formulas 10 and 11 of the embodiment.

The fourth estimation unit 406 uses Equation 12 to calculate the estimated torque τ1 of the _first joint JTAA1. Further, the fourth estimation unit 406 uses Equation 15 to calculate the estimated deformation amount Δθ1 of the _first joint JTAA1. The fourth estimator 406 uses Equation 17 to calculate the estimated deformation amount Δ _1о of the first link 101A. The fourth estimator 406 converts the estimated deformation amount Δ1о of the first link 101A into the estimated deformation amount _ΔθL1 of the _first joint JTAA1 using Equation (19).

(Modification 2)
This modification differs from the embodiment in that the first robot arm 100B has three joints. In the following, this modification will be described with a focus on the points that are different from the embodiment and modification 1, and the description of the points that are the same as those of the embodiment and modification 1 will be omitted as appropriate.

FIG. 7 is a side view modeling the configuration of the robot 1B according to Modification 2. As shown in FIG. As shown in FIG. 7, the robot 1B includes a second robot arm 200 and a first robot arm 100B similar to those of the embodiment. The first robot arm 100B comprises links 101B, 102B, 103B and 104B and joints JTAB1, JTAB2 and JTAB3. Although not limited to this, the links 101B and 102B of this modification have the same configurations as the links 101 and 102 of the embodiment, respectively, and the fourth link 104B of this modification is the third link of the embodiment. It has the same configuration as 103 . The joints JTAB1 and JTAB2 of this modified example have the same configurations as the joints JTA1 and JTA2 of the embodiment, respectively.

One end of the third link 103B of this modified example is connected to the second link 102B by a third joint JTAB3. A second robot arm 200 is attached to the other end of the third link 103B of this modified example, similarly to the second link 102 of the embodiment. The third joint JTAB3 is rotatable about a third axis S3 extending in a direction perpendicular to the support surface S. The directions of the first axis S1, the second axis S2, and the third axis S3 may be any directions, and may be different or the same. The robot 1B includes a control device 300 including an information processing device 300A and a robot controller 300B similar to those of the embodiment. The information processing device 300A performs the same processing as in the embodiment, but performs calculations using a different arithmetic expression from the embodiment in the following points.

Inertial element estimator 409 uses Equation 1 to calculate inertial features L _{1 '} , L 2 ', and L ₃ ' of links _101B , 102B, and 103B, respectively.

The inertial force estimator 410 uses Equation 3 to calculate the joint screws M 1 ', M _{2 '} and M 3 ' of the joints _JTAB1 , _JTAB2 and JTAB3, respectively.

Inertial force estimating section 410 uses Equations 22 to 30 below instead of Equations 6 to 9 of the embodiment to calculate estimated accelerations θ ₁ ^″ , θ ₁₂ ^″ and Joint-induced inertial forces _F11o , _F12o , _F13o , _F21o , _F22o , _F23o , _F31o , _F32o and _F33o generated in the links 101B, 102B and 103B by _θ3 ^'' are calculated. In this calculation, the inertial force estimation unit 410 calculates the estimated accelerations θ ₁ ^″ , θ ₁₂ ^″ and θ ₃ ^″ of the joints JTAB1, JTAB2 and JTAB3, respectively, and the inertial feature L _{1 о} of each of the links 101B, 102B and 103B. , _L2o and _L3o , the inertial feature L _ao of the second robot arm 200, and the joint screws M1o, M2o and M3o of the joints _JTAB1 , _JTAB2 and _JTAB3 , respectively.

Third estimating section 405 calculates the estimated inertia forces F _{1 о} , F _{2 о} , and F _{Calculate 3о} .

The fourth estimation unit 406 uses the following equations 34 to 36 instead of the equations 12 and 13 of the embodiment to calculate the estimated torques τ ₁ , τ ₂ and τ ₃ acting on the joints JTAB1, JTAB2 and JTAB3, respectively. to calculate

The fourth estimating unit 406 calculates the estimated deformation amounts Δθ ₁ , Δθ ₂ and Δθ ₃ of the joints JTAB1, JTAB2 and JTAB3 by using the following expressions 37 to 39 instead of the expressions 15 and 16 of the embodiment. Calculate. In this calculation, the fourth estimation unit 406 uses the stiffnesses k _g1 , k _g2 and k _g3 of the joints JTAB1, JTAB2 and JTAB3, respectively.

The fourth estimating unit 406 uses the following equations 40 to 42 instead of the equations 17 and 18 of the embodiment to calculate the estimated deformation amounts Δ ₁ , Δ ₂ , and Δ ₃ , respectively, of the links 101B, 102B, and 103B. Calculate. In this calculation, the fourth estimator 406 uses the compliances C _I1o , C _I2o and C _I3o of the links 101B, 102B and 103B, respectively.

The fourth estimation unit 406 converts the estimated deformation amounts Δ ₁ , Δ ₂ , and Δ 3 ® of the links 101B, 102B, and 103B into the estimated deformation amounts ΔθL ₁ , ΔθL ₂ , and ΔθL ₃ of the joints JTAB1, JTAB2, and _JTAB3 using Equation 19. Convert.

(Other embodiments)
Although the embodiments and modifications of the present disclosure have been described above, the present disclosure is not limited to the above embodiments and modifications. That is, various modifications and improvements are possible within the scope of the present disclosure. For example, embodiments and modified examples with various modifications, and forms constructed by combining components of different embodiments and modified examples are also included within the scope of the present disclosure.

For example, in the embodiments and modified examples, the number of joints of the first robot arm is 1, 2 or 3, but the number of joints of the first robot arm may be 4 or more. . Also in this case, the control device 300 can perform the same control as in the embodiment and the modification.

Also, in the embodiment and modification, the degree of freedom of the joints of the first robot arm and the second robot arm is one, but the invention is not limited to this. Even if the degrees of freedom of the joints of the first robot arm and the second robot arm are two or more, the control device 300 can perform the same control as in the embodiment and modifications.

Further, in the embodiment and the modified examples, a case where the robot 1 performs the work of holding the object W is exemplified. And the same control as the modified example can be performed.

In addition, examples of aspects of the technology of the present disclosure are listed as follows. A control device according to an aspect of the present disclosure is a control device for a first robot arm having at least two links that support a second robot arm and at least one joint that interconnects the at least two links. to acquire a first motion command for causing the first robot arm to perform a first target motion, which is a target motion, and to obtain a motion command for the at least one joint when the first robot arm moves according to the first motion command. A first estimating unit for estimating a motion, and a second motion command for causing the second robot arm to perform a second target motion that is a target motion, and the second robot arm operates according to the second motion command. a second estimator for estimating a force applied from the second robot arm to a connecting portion between the second robot arm and the link; and an operation of the at least one joint estimated by the first estimator. , a third estimating unit that estimates the force received by the link based on the force estimated by the second estimating unit; a deformation amount of the link based on the force estimated by the third estimating unit; a fourth estimator for estimating at least one of a deformation amount of at least one joint; and moving the connection portion according to the first target motion based on the deformation amount estimated by the fourth estimator. a correction command unit that generates a correction command for the first motion command for compensating for the deformation amount, and commands the correction command to the first robot arm.

According to the above aspect, the control device controls the amount of deformation that occurs in the links and/or joints of the first robot arm when the first robot arm performs the first target motion and the second robot arm performs the second target motion. to estimate The amount of deformation may cause a difference between the actual motion of the connecting portion according to the first motion command and the first target motion. By issuing a correction command to the first robot arm, the control device can cause the first robot arm to perform an operation in which the difference is reduced, that is, an operation in which the amount of deformation is compensated. Therefore, the control device can suppress unintended displacement of the connecting portion from the target position and unintended rocking due to deformation of the link and/or deformation of the joint. Therefore, unintended variation in the position of the connecting portion, which is the base of the second robot arm, is suppressed.

In the control device according to one aspect of the present disclosure, the at least two links include a proximal link and a first link connected to the proximal link and the second robot arm, and the at least one joint is , a first joint connecting the first link to the proximal link, the first estimating unit estimating a motion of the first joint, and the third estimating unit estimating by the first estimating unit and the force estimated by the second estimation unit, the force received by the first link is estimated by the fourth estimation unit. At least one of the amount of deformation of the first link and the amount of deformation of the first joint may be estimated based on the force received by the first link.

According to the above aspect, the control device can control the first robot arm having one joint, and suppress unintended changes in the position of the base of the second robot arm.

In the control device according to one aspect of the present disclosure, the at least two links include a base end link, a first link connected to the base end link, and a second link connected to the second robot arm. wherein the at least one joint includes a first joint that connects the first link to the base end link and a second joint that connects the second link to the first link; and the first estimator estimates the motions of the first joint and the second joint, and the third estimation unit estimates the motions of the first joint and the second joint estimated by the first estimation unit, and the second estimation the third estimating unit estimates the force received by the first link based on the force estimated by the first estimating unit, and the motion of the first joint and the second joint estimated by the first estimating unit; and the force estimated by the second estimating section, and the fourth estimating section estimates the force received by the first link based on the force estimated by the third estimating section. , at least one of the deformation amount of the first link and the deformation amount of the first joint is estimated, and the fourth estimation unit estimates the force received by the second link estimated by the third estimation unit. Based on this, at least one of the deformation amount of the second link and the deformation amount of the second joint may be estimated.

According to the above aspect, the control device can control the first robot arm having two joints and suppress unintended changes in the position of the base of the second robot arm. The control device uses all of the estimated motion of the first joint and the estimated motion of the second joint to estimate the force that the first link receives and the force that the second link receives. Therefore, the accuracy of estimating the force applied to each link is improved, thereby improving the accuracy of estimating the amount of deformation of each link and each joint.

A control device according to an aspect of the present disclosure estimates an inertial force generated in the link by the operation of the at least one joint based on the operation of the at least one joint estimated by the first estimation unit. An inertial force estimating section is further included, and the third estimating section estimates the force applied to the link based on the inertial force estimated by the inertial force estimating section and the force estimated by the second estimating section. may

According to the above aspect, the control device estimates the inertial force of the link that is generated due to the motion of the joint, and uses the estimated inertial force of the link to estimate the force that the link receives. Therefore, the accuracy of estimating the force applied to the link is improved.

A control device according to an aspect of the present disclosure includes a first position estimating unit that estimates the position of the link, a second position estimating unit that estimates the position of the connecting portion, an inertial characteristic of the link and the second an inertia element estimator for estimating an inertial characteristic of the robot arm, the inertial characteristic of the link including the moment of inertia and the mass of the link as elements, and the inertial characteristic of the second robot arm being: The moment of inertia and the mass of the second robot arm are included as elements, and the force-of-inertia estimating unit calculates the inertia characteristics of the link, the inertia characteristics of the second robot arm, the acceleration of the at least one joint, estimating the inertial force generated in the link using a joint screw of the at least one joint, wherein the joint screw includes an element indicating an orientation of the at least one joint; It may be a feature indicating

According to the above aspect, the inertial characteristics include a moment of inertia component and a mass component. The control device uses the inertial characteristics of the link and the second robot arm to estimate the inertial force generated in the link due to the motion of the joint. Therefore, the estimation accuracy of the inertial force is improved.

A robot according to an aspect of the present disclosure includes a control device according to an aspect of the present disclosure, the first robot arm, and the second robot arm. According to the above aspect, the same effect as that of the control device according to the aspect of the present disclosure can be obtained. The robot can cause the first robot arm and the second robot arm to perform the target motion while suppressing unintended changes in the position of the base of the second robot arm.

In the robot according to one aspect of the present disclosure, the control device is configured to generate the first motion command and the second motion command, and control motions of the first robot arm and the second robot arm. may According to the above aspect, the control device can function as a robot controller. That is, the robot controller can cause the first robot arm and the second robot arm to perform the target motion while suppressing unintended changes in the position of the base of the second robot arm.

In addition, all numbers such as ordinal numbers and numbers used above are examples for specifically describing the technology of the present disclosure, and the present disclosure is not limited to the numbers exemplified. Also, the connection relationship between the components is an example for specifically describing the technology of the present disclosure, and the connection relationship for realizing the function of the present disclosure is not limited to this.

Also, the division of blocks in the functional block diagram is an example, and a plurality of blocks may be implemented as one block, one block may be divided into a plurality of blocks, and/or some functions may be moved to other blocks. good. Also, a single piece of hardware or software may process functions of multiple blocks having similar functions in parallel or in a time division manner.

1, 1A, 1B Robots 100, 100A, 100B First robot arms 101, 101A, 101B First links 102, 102A, 102B Second links 103 Links (proximal links)
103B Third link 104B Fourth link (proximal link)
110 connection part (interface)
200 Second robot arm 300 Control device 300A Information processing device 300B Robot controller 403 First estimation unit 404 Second estimation unit 405 Third estimation unit 406 Fourth estimation unit 407 First position estimation unit 408 Second position estimation unit 409 Inertia element Estimation unit 410 Inertia force estimation unit 411 Correction instruction unit JTA1, JTAA1, JTAB1 First joint JTA2, JTAB2 Second joint JTAB3 Third joint

Claims (7)

A control device for a first robot arm having at least two links supporting a second robot arm and at least one joint interconnecting the at least two links,
acquiring a first motion command for causing the first robot arm to perform a first target motion, which is a target motion, and determining motion of the at least one joint when the first robot arm moves according to the first motion command; a first estimation unit that estimates;
A second motion command for causing the second robot arm to perform a second target motion, which is a target motion, is acquired, and when the second robot arm moves according to the second motion command, the second robot arm and the a second estimator for estimating a force applied to the connection portion with the link from the second robot arm;
a third estimating unit that estimates the force applied to the link based on the motion of the at least one joint estimated by the first estimating unit and the force estimated by the second estimating unit;
a fourth estimation unit that estimates at least one of the deformation amount of the link and the deformation amount of the at least one joint based on the force estimated by the third estimation unit;
based on the amount of deformation estimated by the fourth estimator, generating a correction command for the first motion command for compensating for the amount of deformation so as to move the connecting portion according to the first target motion; a correction command unit that commands a command to the first robot arm. the at least two links include a proximal link and a first link connected to the proximal link and the second robot arm;
the at least one joint includes a first joint connecting the first link to the proximal link;
The first estimation unit estimates the motion of the first joint,
the third estimating unit estimates the force applied to the first link based on the motion of the first joint estimated by the first estimating unit and the force estimated by the second estimating unit;
The fourth estimation unit estimates at least one of a deformation amount of the first link and a deformation amount of the first joint based on the force received by the first link estimated by the third estimation unit. A control device according to claim 1 . the at least two links include a proximal link, a first link connected to the proximal link, and a second link connected to the second robot arm;
the at least one joint includes a first joint connecting the first link to the proximal link and a second joint connecting the second link to the first link;
The first estimation unit estimates motions of the first joint and the second joint,
The third estimating unit is configured to generate a force that the first link receives based on the motions of the first joint and the second joint estimated by the first estimating unit and the force estimated by the second estimating unit. , and
The third estimating unit is configured to generate a force that the second link receives based on the motions of the first joint and the second joint estimated by the first estimating unit and the force estimated by the second estimating unit. , and
The fourth estimation unit estimates at least one of a deformation amount of the first link and a deformation amount of the first joint based on the force received by the first link estimated by the third estimation unit. ,
The fourth estimation unit estimates at least one of a deformation amount of the second link and a deformation amount of the second joint based on the force received by the second link estimated by the third estimation unit. A control device according to claim 1 . further comprising an inertial force estimator estimating an inertial force generated in the link due to the motion of the at least one joint based on the motion of the at least one joint estimated by the first estimator;
4. The third estimator estimates the force applied to the link based on the force of inertia estimated by the force-of-inertia estimator and the force estimated by the second estimator. 1. The control device according to claim 1. a first position estimator that estimates the position of the link;
a second position estimator for estimating the position of the connecting portion;
an inertial element estimating unit that estimates the inertial characteristics of the link and the inertial characteristics of the second robot arm;
the inertial characteristics of the link include the moment of inertia and mass of the link as factors;
the inertial characteristics of the second robot arm include the moment of inertia and the mass of the second robot arm as elements;
The inertial force estimator uses the inertial characteristics of the link, the inertial characteristics of the second robot arm, the acceleration of the at least one joint, and the joint screw of the at least one joint to determine the link estimating the inertial force occurring at
5. The control device of claim 4, wherein the joint screw includes a feature indicating the state of the at least one joint including an element indicating the orientation of the at least one joint. A control device according to any one of claims 1 to 5;
the first robot arm;
A robot comprising the second robot arm. 7. The robot of claim 6, wherein the controller is configured to generate the first motion command and the second motion command and to control motion of the first robot arm and the second robot arm.

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