JPH05253864A - Master slave manipulator - Google Patents

Abstract

PURPOSE:To provide a master slave manipulator which realizes excellent operationablity even if a slave arm is located in remote areas, concurrently minimizes operation load at the slave arm side, and also can quickly deal with interference which is applied to the slave arm from the outside. CONSTITUTION:Operation process devices are separately disposed to a master arm 501 and a slave arm 502, and both of them are connected to each other by a serial communication. A master arm operation processing device 504 is equipped with a master command value generating section 504B performing control operations for the master arm 501, and with a slave command value generating section 5O4A generating action commands to the terminal of the slave arm 502, and each action command signal is so designed as to be applied onto communication signals to a slave arm operation processing device 507 from the master arm operation processing device 504. The slave arm operation processing device 507 is equipped with a control. circuit which corrects the command signal to the terminal of the slave arm 502 based on the signal from outside sensors.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a master-slave manipulator operated by an operator, and more particularly to a manipulator control system suitable for surely performing work in an environment that humans cannot withstand, such as space.

[0002]

2. Description of the Related Art Conventionally, as a remote control manipulator, a basic bilateral master-slave manipulator has been known as disclosed in, for example, Japanese Patent Laid-Open No. 63-77670. First, a conventional technique will be described with reference to FIGS. 4 is a perspective view showing a hardware configuration of a conventional master-slave manipulator, FIG. 5 is a block diagram showing a signal flow of the device of FIG. 2, and FIG. 6 is a block of a control system of the master-slave manipulator of FIG. It is a diagram.

In FIG. 4, 201 is a master arm and 2 is a master arm.
Reference numeral 02 is a slave arm, 203 is a master arm input / output device, 204 is a slave arm input / output device, and 205 is an arithmetic processing device that performs all control calculations regarding the master arm and the slave arm. In addition, the master arm 201
6-axis force sensor 2 for detecting force and torque on the wrist
06, and similarly, a wrist portion of the slave arm 202 is also provided with a 6-axis force sensor 207.

FIG. 5 shows in detail the signal flow at this time. The actuators 401 to 406 are attached to the first to sixth joints of the master arm 201 and drive the respective joints, while the respective joint angles at that time are the same as the first to sixth joints.
It is adapted to be detected by the joint angle sensors 407 to 412 provided in the sixth joint. Similarly, the actuators 413 to 418 are the first to sixth actuators of the slave arm 202.
While being attached to a joint and driving each joint, each joint angle at that time is detected by joint angle sensors 419 to 424 also provided to the first to sixth joints.

Further, although represented by a single line in the figure,
Since the signals from the 6-axis force sensor 206 for the master arm and the 6-axis force sensor 207 for the slave arm are forces / torques for 6 axes, there are 6 types of signals respectively. All of the above signals are output from or input to the arithmetic processing unit 205. At that time,
A signal regarding the master arm 201 is transmitted via the master arm input / output device 203, and a signal regarding the slave arm 202 is transmitted via the slave arm input / output device 204.

FIG. 6 shows a control algorithm according to the prior art, and this processing is performed by the arithmetic processing unit 205. When the operator operates the master arm 201, the position / posture state signal 107 of the tip of the master arm is obtained by positively converting a plurality of joint angle signals 106 of the master arm 201. This signal 107 is used by the slave command value generation unit to generate the target value 306 of the position / orientation to the slave. The slave command value generation unit will be described later in detail, but here, the position / posture state signal 107 at the tip of the master arm is assumed to be a unit matrix.
Shall be output as is. At this time, the position / posture state signal 305 of the tip of the slave arm can be obtained by similarly performing the positive conversion from the plurality of joint angle signals 304 of the slave arm.

Now, the purpose of this control is that the slave arm 202 is positioned at the position of the tip of the master arm 201.
The position / orientation state signals 305 and 306 must match because they move in accordance with the posture or move in accordance with the posture. Therefore, the master arm position / attitude command signal 30
By subtracting the slave arm position / posture state signal 305 from 6, a position / posture difference signal 307 in which the slave arm 202 should move is obtained, and by inversely converting this, each joint of the slave arm 202 should be driven. The command value 308 is output and the slave arm 202 is driven.

On the other hand, the purpose of driving the master arm 201 is to convey the force received by the slave arm 202 to the operator at the same time as the master arm itself moves according to the operation of the operator.
1, it is driven based on signals 101 and 109 from a 6-axis force sensor attached to the wrist of the slave arm 202. Specifically, the force / torque signal 101 from the 6-axis force sensor 206 on the wrist of the master arm 201
Is expressed in the coordinate system of the 6-axis force sensor 206 itself, that is, in the coordinate system of the wrist of the master arm 201, so that this is positively converted to obtain the force / torque signal 102 expressed in the reference coordinate system. Similarly, the force / torque signal 109 from the 6-axis force sensor 207 attached to the wrist of the slave arm 202 is positively converted, and the force / torque applied to the wrist of the slave arm 202 is represented by a reference coordinate system. The signal 110 is obtained.

Further, slave arm force / torque signal 1
By subtracting the master arm force / torque signal 102 from 10, the force / torque difference signal 301 is output. A master command value generation unit generates a target position / posture value 302 of the tip of the master arm 201 from the difference signal 301, and inversely converts the target value 302 to obtain a command value 303 for each joint of the master arm 201. You can

Here, depending on the mode, the master arm 20
If the command state of the slave arm 202 by 1 can be changed, the operability is improved. That is, in the first operation mode, the master arm is operated by a position command from the slave arm, and the movement amount of the master arm becomes the movement amount of the slave arm as it is. In the second operation mode, the master arm is operated by a speed command from the slave arm, and the movement amount of the master arm from the reference position is the speed of the slave arm.

In the first operation mode, the operation of the master arm 201 continues to move in that direction when the operator is exerting a force, so that the master command value generating section is integrated. Further, since the operation of the slave arm 202 is to move in accordance with the position / posture of the master arm 201, the slave command value generation unit is a unit matrix. Here, if the slave command value generation unit is a diagonal matrix, the operation ratio of the slave 202 to the master arm 201 can be changed according to the value of the diagonal element.

Next, in the second operation mode, the master arm 201 operates like a joystick. That is, it is necessary to displace from the reference position according to the force applied by the operator and return to the reference position when the operator is not applying the force. Therefore, the master command value generation unit is a diagonal matrix. At this time, the slave arm 202
Since the operation of (1) moves at a speed according to the deviation of the master arm 201 from the reference position, the slave command value generation unit is an integral.

By the above method, the slave arm 202 makes a movement corresponding to the position / orientation of the master arm 201, and the operator can feel the force applied to the tip of the slave arm 202 as it is. As a result, when the slave arm comes into contact with the work target, the reaction force returns to the operator's hand, so that the operator can move the reaction force in a direction to mitigate the reaction force and avoid the danger. Also, various modes can be switched.

Further, in the case of an industrial robot which moves in response to a computer command, when the arm contacts the work target, the operator is not operating as described above. Compliance control is performed. Compliance control is based on Hitachi Review Vol. 6
6, No. 10, pp35 / 40, "Development of basic technology for assembling FA robot", the arm tip is driven by a contact force as if it is virtually supported by a spring. In order to realize this, an external force is detected by a force sensor attached to the arm wrist, and this force is controlled by superimposing it on the arm tip position / posture.

[0015]

The above-mentioned prior art is for the case where the master arm and the slave arm are arranged close to each other. For example, the master arm on the ground is operated to set the slave arm in the outer space. In the case of moving it, the cycle time becomes long due to the influence of communication time delay, etc., and there is a problem that it is not possible to cope with it by only having one arithmetic processing unit on the ground side or the space side. In addition, the space side cannot have a high-performance computer due to resource limitation, but even in that case, no consideration was given to the separation of functions between the ground side and the space side in order to realize comfortable operability.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and realizes good operability and stable control even if the slave arm is arranged at a remote place with respect to the master arm. It is an object of the present invention to provide a master-slave manipulator that enables the operation load on the slave arm side to the minimum while enabling it. Another object of the present invention is to provide a master-slave manipulator capable of promptly dealing with interference received by the slave arm from the outside.

[0017]

In order to achieve the above object, the configuration of the first invention relating to the master-slave manipulator of the present invention is a master arm, a slave arm, an input / output device for each arm, and an arm for each arm. In a master-slave manipulator system including at least two arithmetic processing devices capable of individually performing arithmetic processing, the at least two arithmetic processing devices are coupled by serial communication, and the master arm arithmetic processing device has a master arm control arithmetic operation. In addition to this, an operation command to the tip of the slave arm is generated, and the operation command signal of the tip of the slave arm is added to the communication signal from the master arm arithmetic processing unit to the slave arm arithmetic processing unit. ..

In order to achieve the above object (including other objects), the structure of the second invention relating to the master-slave manipulator of the present invention is a master arm, a slave arm, an input / output device for each arm, and In a master-slave manipulator system including at least two arithmetic processing units capable of individually performing arithmetic processing of each arm, the at least two arithmetic processing units are coupled by serial communication, and the arithmetic processing unit for the master arm is a master arm. And a slave command value generation unit for generating an operation command for the tip of the slave arm, and the master arm arithmetic processing device includes a master command value generation unit for generating a control command of the slave arm. The operation command signal from the tip of the slave arm should be placed on the Comprising a sensor, the slave arm processor, to the command signal of the slave arm tip, in which a control circuit including a compliance superimposing section that performs a correction based on a signal from the external sensor.

That is, in summary, in addition to individually arranging arithmetic processing units in each of the master arm and the slave arm and connecting them by serial communication,
In order to minimize the load on the slave arm side processor, the master arm side processor performs all possible calculations, and communication from the master arm side to the slave side is performed from the slave arm tip. I sent the command value. Further, as a fine adjustment on the slave side, the command signal is corrected using the signal of the external sensor.

[0020]

[Operation] By dividing the arithmetic processing unit for controlling the master arm and the slave arm and providing each with a control arithmetic loop, the cycle time can be speeded up regardless of the communication time. There is no lowering. In addition, for communication from the master arm side to the slave side, by sending a command signal to the tip of the slave arm, the arithmetic processing unit on the space side performs a slight correction and minimum processing such as coordinate conversion calculation. The slave arm can be controlled. Therefore, even the space side arithmetic processing device having a limited function can perform arithmetic in a short cycle time.

Further, by correcting the command signal using the signal of the external sensor such as the force / torque sensor, it is possible to avoid applying a great force to the slave arm, and the force feedback control is performed to improve the positioning accuracy. be able to.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram of a control system of a master-slave manipulator according to an embodiment of the present invention,
2 is a perspective view showing a hardware configuration of a master-slave manipulator according to an embodiment of the present invention, and FIG. 3 is a block diagram showing a signal flow of the device of FIG. Figure 2
Shows an example of moving a slave arm on an artificial satellite by a ground master arm.

In FIG. 2, reference numeral 501 denotes a ground-side master arm, and a master arm input / output device 503 and a master arm arithmetic processing device 504 are stored in a panel equipped with the master arm 501. Further, 502 is a slave arm on the artificial satellite, 506 is a slave arm input / output device, and 507 is a slave arm arithmetic processing device. Further, the wrist portion of the master arm 501 is provided with a 6-axis force sensor 509 for detecting force and torque,
Similarly, the wrist portion of the slave arm 502 is also equipped with a 6-axis force sensor 510. Master arm processor 5
The command signal to the slave arm generated by 04 is transmitted to the slave arm communication system 508 through the ground station 505 by serial communication.

FIG. 3 shows in detail the signal flow at this time. The actuators 601 to 606 are attached to the first to sixth joints of the master arm 501 to drive the respective joints, and the respective joint angles at that time are determined by joint angle sensors 607 to 612 similarly provided to the first to sixth joints. It is supposed to be detected. Similarly, the actuators 613 to 618 are attached to the first to sixth joints of the slave arm 502 and drive the respective joints, while the respective joint angles at that time are the joint angle sensors 619 also provided to the first to sixth joints. ˜624. Further, although shown by a single line in FIG. 3, since the signal from the 6-axis force sensor for master arm 509 and the signal from the 6-axis force sensor for slave arm 510 are forces / torques for 6 axes, respectively. There are 6 types of signals each.

Of the above signals, the signal relating to the master arm 501 is input and output to the master arm arithmetic processing unit 504 via the master arm input / output unit 503. Similarly, a signal related to the slave arm 502 is input and output to the slave arm arithmetic processing unit 507 via the slave arm input / output device 506. here,
Basically, the control calculation regarding the master arm is performed by the master arm arithmetic processing unit 504, and the control calculation regarding the slave arm is performed by the slave arm arithmetic processing unit 507, but normally, the computer on the orbit is inferior in function to the computer on the ground. Therefore, in order to reduce the load on the slave arm arithmetic processing unit 507, all calculations that can be performed by the master arm arithmetic processing unit 504 are performed, and data by serial communication from the master arm arithmetic processing unit 504 to the slave arm arithmetic processing unit 507. The delivery is performed by the command value of the tip position / posture of the slave arm.

FIG. 1 shows a control algorithm for implementing the present invention. In this processing, the left side from the alternate long and short dash line is performed by the master arm arithmetic processing unit 504, and the right side is performed by the slave arm arithmetic processing unit 507. .. When the operator operates the master arm 501, the master arm 5
The position / posture state signal 107 of the tip of the master arm is obtained by positively converting the plurality of joint angle signals 106 of 01. This signal 107 causes the slave command value generator 504A to generate a target position / orientation value 108 for the slave. This slave command value generation unit 504A
Is the same as that described in the prior art, and here it is assumed that the position / posture state signal 107 at the tip of the master arm is output as it is, assuming that it is a unit matrix.

Now, the purpose of this control is to make the slave arm 502 move in conformity with or in accordance with the position / posture of the tip of the master arm 501. Therefore, the slave arm 502 follows the position / posture command signal 108. 502 must move. Therefore, it is simply necessary to perform the reverse conversion to obtain the angle of each joint of the slave arm and drive it, but in reality, when the slave arm contacts the work target, it receives a strong reaction force and becomes a dangerous situation. There is a chance. In the conventional technology, by returning the reaction force to the operator's hand, it is possible to move the reaction force in a direction to mitigate the reaction force at the operator's discretion, but in the case of this control, it takes time to communicate between the slave side and the master side. Therefore, the method based on the operator's judgment cannot be taken.

Therefore, compliance control is applied here. That is, the slave arm 50
The force / torque signal 109 from the 6-axis force sensor 510 attached to the wrist portion of No. 2 is positively converted to obtain the force / torque 110 expressed in the reference coordinate system. The compliance superimposing unit 507A superimposes the compliance on the slave command value signal 108 to obtain a command value 111 to the slave arm including the relaxation of the force, and further inversely converts the command value 111 to determine each joint of the slave arm 502. Command value to drive 1
After obtaining 12, the slave arm 502 is driven.

On the other hand, the purpose of driving the master arm 501 is to move the master arm itself according to the operation of the operator. Explaining this control method, the force / torque signal 101 from the 6-axis force sensor 509 on the wrist of the master arm 501 is positively converted to obtain a force / torque signal 102 expressed in a reference coordinate system. From this signal 102, the position of the tip of the master arm 501 /
A command value 104 for each joint of the master arm 501 is generated by generating a posture target value 103 and inversely converting the target value 103.
Then, the master arm 501 is driven.

According to the present embodiment, even if the slave arm 502 is installed at a remote place with respect to the master arm 501, communication time is not included in the loop of control calculation,
A normal master-slave operation can be realized by a high-speed cycle time. Further, at that time, all processing associated with the switching of the operation mode is performed by the arithmetic processing device 504 on the master arm side, and the arithmetic processing device 5 on the slave arm side is executed.
By giving a communication signal to 07 as a command value of the slave arm tip position / orientation, the load on the arithmetic processing device 507 on the slave arm side can be minimized, so that the arithmetic processing device 507 on the slave arm side, which is inferior in function, also supports it. can do.

Further, the arithmetic processing unit 5 on the master arm side
The slave arm tip position / posture command value sent from the slave No. 04 is subjected to the primary correction by the external sensor on the slave arm side, so that the slave arm 502 can promptly deal with the interference received from the external environment. it can.

[0032]

As described above in detail, according to the present invention, even if the slave arm is located at a remote place with respect to the master arm, good operability is realized and stable control is possible. At the same time, it is possible to provide a master-slave manipulator that can minimize the calculation load on the slave arm side. Further, according to the present invention, it is possible to provide a master-slave manipulator capable of promptly coping with interference that the slave arm receives from the outside world.

[Brief description of drawings]

FIG. 1 is a block diagram of a control system of a master-slave manipulator according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a hardware configuration of a master-slave manipulator according to an embodiment of the present invention.

FIG. 3 is a block diagram showing a signal flow of the device of FIG.

FIG. 4 is a perspective view showing a hardware configuration of a conventional master slave manipulator.

5 is a block diagram showing a signal flow of the device of FIG.

FIG. 6 is a block diagram of a control system of the master-slave manipulator in FIG.

[Explanation of reference numerals] 501 master arm 502 slave arm 503 master arm input / output device 504 master arm arithmetic processing device 504A slave command value generation unit 504B master command value generation unit 506 slave arm input / output device 507 slave arm arithmetic processing device 507A compliance superposition 509 Master arm 6-axis force sensor 510 Slave arm 6-axis force sensor

Claims (6)

[Claims] 1. A master-slave manipulator system comprising a master arm, a slave arm, an input / output device for each arm, and at least two arithmetic processing devices capable of individually performing arithmetic processing for each arm, wherein the at least two arithmetic processing devices are provided. The master arm arithmetic processing unit generates an operation command to the tip of the slave arm in addition to the master arm control arithmetic operation, and the master arm arithmetic processing unit transmits the master arm arithmetic processing unit from the master arm arithmetic processing unit to the slave arm arithmetic processing unit. A master-slave manipulator characterized in that the operation command signal of the tip of the slave arm is put on a communication signal to the master-slave manipulator. 2. A master-slave manipulator system comprising a master arm, a slave arm, an input / output device for each arm, and at least two arithmetic processing devices capable of individually performing arithmetic processing for each arm, wherein the at least two arithmetic processing devices are provided. The master arm arithmetic processing unit includes a master command value generation unit that performs a control calculation of the master arm and a slave command value generation unit that generates an operation command for the tip of the slave arm. The operation command signal of the tip of the slave arm is placed on the communication signal from the arm arithmetic processing device to the slave arm arithmetic processing device, and the slave arm is provided with an external sensor, and the slave arm arithmetic processing device is For the command signal at the tip of the slave arm, is the external sensor Master slave manipulator, characterized in that it comprises a control circuit including compliance superimposing section that performs, based on the signal correction. 3. The master arm has two or more operation command modes to the slave arm, and the processing for switching between these modes is performed by the master arm arithmetic processing unit. That master-slave manipulator. 4. The command signal relating to the slave arm tip position is carried on serial communication from the master arm arithmetic processing unit to the slave arm arithmetic processing unit. Master slave manipulator. 5. The command signal relating to the slave arm tip speed is carried on the serial communication from the master arm arithmetic processing unit to the slave arm arithmetic processing unit. Master slave manipulator. 6. The master-slave manipulator according to claim 2, wherein the external sensor is a sensor that detects force and torque.