JP2013121634A - Robot device and control method of robot device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a robot and a control method capable of restraining the vibration of a robot arm, particularly, vibration when stopping in a target position in an arm tip having a work mechanism by a simple control system.SOLUTION: The robot device includes an arm connecting device including an actuator and an angle sensor, an arm body, a base body rotatably connected with the arm body, and an inertia sensor in a work arm attached with a workpiece holding means, and includes a first arithmetic operation part for arithmetically operating the angular velocity of the arms, a second arithmetic operation part for arithmetically operating the angular velocity in an installation position of the inertia sensor of the work arm, a third arithmetic operation part for arithmetically operating torsional angular velocity between the arms, a fourth arithmetic operation part for arithmetically operating an overshoot of the work arm, and a control part having a comparing means of the overshoot of the work arm and an overshoot specified value, and increasing and decreasing a speed loop integral gain by an overshoot comparing result of the comparing means.

Description

  The present invention relates to a robot apparatus and a method for controlling the robot apparatus.

  A robot apparatus having a multi-joint structure, which is often used as a part of an IC handler or an assembly apparatus, has been widely used in various industrial sites. Therefore, it has become an important performance specification and quality for a robot apparatus to be able to move an arm quickly and accurately to a required position more than ever. In general, in order to move the arm at high speed and accurately, it is necessary to reduce the inertial force applied to the arm and not to increase the load of the driving actuator. In order to reduce the inertial force applied to the arm, weight reduction of the arm is used as the most effective method. However, reducing the weight of the arm causes a decrease in arm rigidity, making it difficult to suppress arm vibration that occurs when the arm is stopped, and it is determined that the arm tip has been stopped at the target position based on the control signal. However, in practice, there is a positional shift corresponding to the amplitude of the vibration of the arm itself, and there is a problem that the next operation cannot be started until the vibration is attenuated.

  To solve this problem, for example, Patent Document 1 includes means for setting a gain adjustment evaluation function that takes into account the elastic deformation of the robot arm, and the control gain based only on the drive position of a drive source such as a motor is set as the gain adjustment that has been set. It is disclosed that by controlling a robot arm using an adjusted control gain adjusted by an evaluation function, it is possible to perform highly accurate control in consideration of elastic deformation of the robot arm.

JP 2001-92511 A

  However, in the above-mentioned Patent Document 1, in addition to the control system for driving the robot arm, a vibration control control system for setting the gain adjustment evaluation function and generating the adjusted control gain must be provided. Had to build.

  Accordingly, a robot apparatus and a control method therefor are provided that can suppress vibration of a robot arm, particularly vibration at the time of stopping a target position at an arm tip provided with a working mechanism, even with a simple control system.

  The present invention can be realized as the following forms or application examples so as to solve at least one of the above-described problems.

  [Application Example 1] In the robot apparatus of this application example, an actuator, an arm connecting device including an angle sensor for detecting a rotation angle of the actuator, and a plurality of arms are connected in series and rotatably by the arm connecting device. A base body in which the arm body is rotatably connected by a base body connecting device including an arm body, an actuator provided at one end of the arm body, and an angle sensor for detecting a rotation angle of the actuator; And an inertial sensor including at least an angular velocity sensor at an attachment position of the work arm to which the work piece holding means is attached. A first calculation unit for calculating the angular velocity of the arm from the angle detection data, and an angle of the inertial sensor. From the degree detection data, a second calculation unit that calculates an angular velocity at the attachment position of the working arm, the angular velocity of the arm, and the angular velocity of the arm calculated by the angular velocity detection data of the inertia sensor, A third calculation unit that calculates a torsional angular velocity between the actuator and the arm connected to the actuator, a fourth calculation unit that calculates an overshoot of the working arm from the torsional angular velocity, A control unit that includes a comparison unit that compares the overshoot of the working arm with an overshoot specified value, and that increases or decreases a speed loop integral gain according to an overshoot comparison result of the comparison unit.

  The overshoot and tact time in this application example will be described with reference to FIG. As shown in FIG. 1, the work arm provided with the work holding means in the arm body of the robot apparatus of this application example receives the operation command from the work arm standby position, and is attached with the work holding means. The mounting position is driven to a predetermined work arm stop specified position. At this time, even if the mounting position of the arm body reaches the specified work arm stop position, the arm body is elastically deformed within the elastic range of the arm body due to the inertia of the arm body, and swings beyond the specified work arm stop position. The amplitude gradually decreases with time from the amplitude, and the arm body stops. The amount of movement from the work arm stop prescribed position to the work arm maximum swing position that appears first is referred to as “overshoot”. The time from the start of driving from the operating arm standby position to the time when the mounting position reaches the operating arm stop specified position is referred to as “tact time”.

  According to the robot apparatus of Application Example 1, even if the overshoot within the initially set overshoot specified value shifts with the passage of operating time and deviates from the overshoot specified value, the speed loop integral gain is increased. By increasing / decreasing, the robot apparatus can be operated within the overshoot specified value for a long time, that is, when the target position is stopped at the installation position of the workpiece holding means provided at the tip of the arm, especially the vibration of the robot arm. Can be obtained. Further, by calculating an overshoot and adjusting an appropriate speed loop integral gain during driving of the robot apparatus, long-term operational stability and productivity can be maintained with initial performance.

  Application Example 2 In the application example described above, the comparison unit compares the tact time of the working arm with a tact time specified value, and the speed loop integral gain is determined based on the overshoot comparison result and the tact time comparison result. It is characterized by increasing or decreasing.

  According to the above application example, in addition to the adjustment of the overshoot, the tact time is adjusted by increasing / decreasing the speed loop integral gain so that the tact time becomes the specified tact time. The robot apparatus can be operated, and productivity can be maintained at the initial performance.

  Application Example 3 In the application example described above, an external display unit that displays the overshoot calculated by the fourth calculation unit and the result of the tact time is provided.

  According to the application example described above, the predetermined display content can be displayed on the external display means, so that the driving of the robot apparatus can be controlled by the operator's judgment, and safety and productivity can be further improved. it can.

  [Application Example 4] A control method of a robot apparatus according to this application example includes an actuator, an arm coupling device including an angle sensor for detecting a rotation angle of the actuator, and a plurality of arms that can be rotated in series by the arm coupling device. A base body in which the arm body is rotatably connected by a base body connecting device including an arm body connected to the arm body, an actuator provided at one end of the arm body, and an angle sensor for detecting a rotation angle of the actuator. And an inertial sensor including at least an angular velocity sensor at an attachment position of the work arm to which the work piece holding means is attached among the plurality of arms. A control method for determining an angular velocity of the arm based on rotation angle detection data of the angle sensor. A first calculation step for calculating; a second calculation step for calculating an angular velocity at the mounting position of the working arm based on angular velocity detection data of the inertia sensor; the angular velocity of the arm; and the angular velocity detection of the inertia sensor. A third calculation step of calculating a torsional angular velocity between the actuator and the arm connected to the actuator based on a difference between the angular velocity of the arm calculated by data, and the working arm from the torsional angular velocity. A fourth calculation step of calculating the overshoot of the working arm, a comparison step of comparing the overshoot of the working arm with an overshoot specified value, and a control step of increasing or decreasing the speed loop integral gain according to the overshoot comparison result of the comparison means It is characterized by including these.

  The control method of the robot apparatus according to this application example is such that even if the overshoot within the initially set overshoot specified value shifts from the overshoot specified value as the operation time elapses, the speed loop integral gain By executing the control method for increasing / decreasing the robot device, the robot apparatus can be operated within the overshoot specified value for a long time, that is, the vibration of the robot arm, particularly the installation of the work holding means provided at the tip of the arm. It is possible to obtain a robot apparatus that can suppress vibration when the target position is stopped at a position. Further, by calculating an overshoot and adjusting an appropriate speed loop integral gain during driving of the robot apparatus, long-term operational stability and productivity can be maintained with initial performance.

  Application Example 5 In the application example described above, in the comparison step, the takt time of the working arm is compared with a specified takt time, and the speed loop integral gain is determined based on the overshoot comparison result and the takt time comparison result. It is characterized by increasing or decreasing.

  According to the application example described above, in addition to the control method for adjusting the overshoot, by executing the control method for adjusting the increase / decrease of the speed loop integral gain so that the tact time becomes the tact time specified value, Thus, the robot apparatus can be operated within the specified tact time, and productivity can be maintained at the initial performance.

  Application Example 6 In the application example described above, an external display process for displaying the result of the overshoot and the tact time calculated in the fourth calculation process is provided.

  According to the application example described above, by providing a step of displaying predetermined display contents on the external display means, it becomes possible to control the driving of the robot apparatus based on the judgment of the operator, and further improve safety and productivity. Can do.

The figure explaining the definition of overshoot and tact time. The robot apparatus which concerns on 1st Embodiment is shown, (a) is a schematic plan view, (b) is a schematic sectional drawing. The control block diagram which shows the structure of the robot apparatus which concerns on 1st Embodiment. The block diagram which shows the robot apparatus shown in FIG. 2 with the connection apparatus represented with the characteristic model. The block diagram which shows the structure of the control means included in the control part shown in FIG. The figure which shows the behavior of arm vibration. The flowchart of the control method of the robot apparatus which concerns on 2nd Embodiment. The flowchart of the gain adjustment method of the robot apparatus which concerns on 2nd Embodiment.

  Embodiments according to the present invention will be described below with reference to the drawings.

(First embodiment)
2A and 2B show the robot apparatus according to the first embodiment, wherein FIG. 2A is a schematic plan view, and FIG. 2B is a schematic cross-sectional view. The robot apparatus according to this embodiment is a so-called two-axis horizontal articulated robot 100 (hereinafter referred to as a robot apparatus 100) in which two arms are connected so as to be rotatable in the horizontal direction.

  The robot apparatus 100 includes an arm body 10 configured by a first arm 11 and a second arm 12 being rotatably connected by an arm connecting device 20. The arm body 10 is rotatably connected to the base body 40 fixed to the base by the base body connecting device 30 to constitute the robot apparatus 100.

  The arm coupling device 20 includes an actuator 51 and a torque transmission device 61 that transmits the torque of the actuator 51 at a predetermined reduction ratio. Moreover, the base | substrate connection apparatus 30 contains the torque transmission apparatus 62 which transmits the actuator 52 and the torque of the actuator 52 with a predetermined reduction ratio. At the end of the second arm 12 which is the end opposite to the base body 40 of the arm body 10, a work holding device 70 is provided as a work holding means for holding a processing tool or a work.

  The actuator 51 included in the arm coupling device 20 is provided with an angle sensor 81 that detects a rotation angle. Further, the actuator 52 is also provided with an angle sensor 82 in the base body connection device 30. In addition, an inertia sensor 90 is provided at a position corresponding to the attachment position P where the work holding device 70 of the second arm 12 is provided. The inertial sensor 90 includes at least an angular velocity sensor, and enables detection of the angular velocity and position at the attachment position of the inertial sensor 90, that is, the attachment position P of the work holding device 70.

  FIG. 3 is a control block diagram illustrating a configuration of the robot apparatus 100 according to the present embodiment. The CPU 200 includes a first calculation unit 510, a second calculation unit 520, a third calculation unit 530, a fourth calculation unit 540, and a control unit 600, which will be described later, and reads and executes a program stored in the ROM 300. The RAM 400 stores data obtained by executing the program in the CPU 200, and sends necessary data from the stored data to the CPU 200.

  The rotation angle data of the actuators 51 and 52 detected by the angle sensors 81 and 82 provided in the robot apparatus 100 are converted into the rotation angle θ1 of the actuator 51 and the rotation angle θ2 of the actuator 52 by the first calculation unit 510 and converted. Each of the rotation angles θ1 and θ2 is differentiated once with respect to time, and the rotation angular velocity of the actuator is calculated.

From the obtained rotational angular velocity of the actuator, the rotational angular velocity of the arm driven by the actuator is obtained. In the case of the first arm 11, since it is driven by the torque transmission device 62 having a reduction ratio 1 / N2 from the actuator 52, the rotational angular velocity ω2 of the output portion of the base body coupling device 30 is
ω2 = (dθ2 / dt) × (1 / N2)
It becomes.

Similarly, the rotational angular velocity ω1 of the output unit of the arm coupling device 20 including the actuator 51 that drives the second arm 12 is:
ω1 = (dθ1 / dt) × (1 / N1)
1 / N1: A reduction ratio of the torque transmission device 61.

In the second calculation unit 520, the position where the inertial sensor 90 having the rotation axis of the base body coupling device 30 as the angular velocity of the arm body 10, that is, the workpiece is detected from the detection value detected by the inertial sensor 90 provided on the second arm 12. The angular velocity ω _a of the holding device 70 is calculated.

In the third calculation unit 530, the angular velocity ω1 of the second arm 12, the angular velocity ω2 of the first arm 11, and the second arm using the connecting device including the actuator 51 by the rotation of the actuator 51 calculated as described above as the rotation axis. The torsional angular velocity ω _b, which is the difference from the angular velocity ω _a of the second arm about the base body coupling device 30 obtained from the inertia sensor 90 attached to the rotation axis 12,
ω _b = ω _a −ω2−ω1
Obtained by. The obtained twist angular velocity ω _b is considered to be a combination of the twist angular velocity ω _b1 caused by the first arm 11 and the twist angular velocity ω _b2 caused by the second arm 12,
ω _b = ω _b1 + ω _b2
It is expressed. In other words, by decomposing the torsional angular velocity ω _b into the torsional angular velocities ω _b1 and ω _b2 caused by the arms 11 and 12, the actuator 51 is configured so that the vibration of the arm body 10 has an appropriate overshoot and tact time. , 52 can be adjusted.

The torsional angular velocity omega _b, torsional angular velocity omega _b1 due to the arms 11 and 12, illustrating a method for decomposing the omega _b2. FIG. 4 is a diagram showing the arm coupling device 20 and the base body coupling device 30 of the robot apparatus 100 shown in FIG. 2 in a characteristic model of spring characteristics and damping characteristics (damper characteristics). As shown in FIG. 4, the arm coupling device 20 of the robot apparatus 100 includes a virtual spring 20a and a virtual damping device 20b, and the first arm 11 and the second arm 12 are coupled. The robot apparatus 100 can be schematically shown as having the first arm 11 connected to the base body 40 with the 30a and the virtual damping device 30b. In the modeled robot apparatus 100, the first arm 11 and the second arm 12 are generally different in weight, length, rigidity, and the like, so that the first arm 11 is provided in the base connecting device 30. Calculation is made using the frequency response when driven by the actuator 52 and the configurations of the virtual springs 20a and 30a and the virtual damping devices 20b and 30b when the second arm 12 is driven by the actuator 51 provided in the arm coupling device 20. It shows different characteristics with the frequency response.

That is, since the first arm 11 can be provided with a high output actuator 52 provided in the base body coupling device 30, it can have high rigidity and weight. On the other hand, since the second arm 12 includes the arm coupling device 20 in the first arm 11, the second arm 12 needs to be a small and low-power actuator 51, so that the weight is reduced. With such a configuration, attention is paid to the fact that the first arm 11 and the second arm 12 have different frequency characteristics, and the torsional angular velocity ω _b is determined from the torsional angular velocities ω _b1 and ω _b2 caused by the arms 11 and 12. Can be broken down into Specifically, the first arithmetic unit 530 filters the torsional angular velocity ω _b with a bandpass filter having respective characteristics corresponding to different frequency characteristics in the first arm 11 and the second arm 12, thereby The twist angular velocity ω _b1 component of the arm 11 and the twist angular velocity ω _b2 component of the second arm 12 can be extracted and obtained.

The torsion angular velocity ω _b1 component of the first arm 11 and the torsion angular velocity ω _b2 component of the second arm 12 obtained in this way are integrated in the fourth calculation unit 540, and the mounting position P (see FIG. 2). The vibration as shown in FIG. 1 is calculated, the overshoot is calculated, and the tact time is also acquired.

  Data on the overshoot and tact time of the mounting position P due to the calculated vibration is sent to the control unit 600. In the control unit 600, the overshoot specified value and the tact time specified value specified as the specifications of the robot apparatus 100, and the overshoot and the tact time sent from the fourth calculation unit 540 are compared. The speed loop integral gain included in the control means 620 included in the control unit 600 is adjusted based on the comparison result in 610.

  FIG. 5 shows a control block diagram as an example of the control means 620. As shown in the control block diagram of FIG. 5, the control means 620 includes a control loop including a speed loop integral gain Kvi 620a (hereinafter referred to as Kvi 620a). Based on the comparison result in the comparison unit 610, the gain adjustment instruction unit 620b instructs the Kvi 620a to increase or decrease the gain, and adjusts the overshoot and the tact time so as to match the specified values. Specifically, the position loop 620c generates a speed command based on the difference between the input position command and the current position detected by the actuators 51 and 52. The position loop 620c is preferably proportional control using a proportional gain Kpp. The speed command and the current position detected by the angle sensors 81 and 82 are differentiated, and proportional control for adjusting the proportional gain Kp620d with respect to the deviation from the actual speed and integration control for adjusting the integral gain Kvi620a are performed. A current command is generated so that the speed is based on the speed command. Then, a current loop 620e (proportional control, integral control) is performed on the difference between the current command and the actual drive current, and control is performed so that a current according to the current command is supplied to the motor. By being controlled in this way, the motor is in a driving state that matches the position command and the speed command.

  Here, gain adjustment will be described. Originally, in the robot apparatus 100 according to the present embodiment, it is preferable that the overshoot and the tact time of the attachment position P are as small as possible. However, as described above, vibration that occurs when the arm body 10 is stopped due to elastic deformation of the arms 11 and 12 is unavoidable, and the overshoot specified value and the tact time based on predetermined specifications are determined depending on the work contents that the robot apparatus 100 performs in advance. A specified value is defined. FIG. 6A shows an operation locus of the mounting position P in a state controlled within the range of the overshoot specified value and the tact time specified value, which are required specifications, and FIG. 6B shows that the overshoot is within the specified value. FIG. 6 (c) shows an operation trajectory of the mounting position P in a state where the tact time exceeds the specified value, and FIG. 6C shows the mounting position P in a state where the tact time is within the specified value but the overshoot exceeds the specified value. An operation locus is shown.

  As shown in FIG. 6A, the robot apparatus 100 is adjusted in advance and manufactured and shipped. That is, the mounting position P starts driving from the S0 position in the standby stop state, and the tact time Ta to the stop specified position Ss is set to be equal to or less than the specified tact time value Ts. Then, after reaching the specified stop position Ss, an overshoot Da is generated by the vibration of the arm body 10, and the vibration is attenuated as time passes. This overshoot Da is also set to be equal to or less than the overshoot specified value Ds, and becomes a vibration form of the operation locus F0 of the attachment position P. This overshoot specified value Ds is set corresponding to an area in which the work holding device 70 can hold the work. However, by operating the robot apparatus 100, the overshoot Da and the tact time Ta gradually change, and may exceed the overshoot specified value Ds and the tact time specified value Ts. That is, it is a case where it becomes a vibration form of the operation locus | trajectory F1, F2 of the attachment position P shown to FIG.6 (b), (c) as an example.

  The motion trajectory F1 shown in FIG. 6B is the vibration of the overshoot motion trajectory F1 with the overshoot Db being smaller than the overshoot specified value Ds. In other words, the vibration is attenuated in a short time. However, as is apparent from the figure, the movement of the mounting position P to the stop specified position Ss is gentler than the movement locus F0 shown in FIG. 6A, and the moving speed of the arm body 10 is slow. Is shown. Therefore, the tact time Tb is longer than the tact time specified value Ts. This increases the time for the work holding device 70 to arrive at the work piece, resulting in a decrease in cycle time, that is, productivity. Therefore, in the case of the operation locus F1 as shown in FIG. 6B, the tact time Tb can be made equal to or less than the tact time specified value Ts by adjusting the overshoot Db closer to the overshoot Ds. Specifically, by increasing the gain in Kvi 620a, the overshoot Db can be increased so that the tact time Tb is decreased. The gain adjustment in Kvi 620a is preferably executed with an adjustment width of 2% in one adjustment operation.

  The operation locus F2 shown in FIG. 6C is the vibration of the overshoot operation locus F2 where the overshoot Dc exceeds the overshoot specified value Ds. As is apparent from the figure, the movement of the mounting position P to the stop specified position Ss is steeper than the movement locus F0 shown in FIG. 6A, and the movement speed of the arm body 10 is increased. Yes. Accordingly, the tact time Tc is shorter than the tact time specified value Ts. However, since the overshoot Dc exceeds the overshoot specified value Ds, the work holding device 70 cannot shift to the work holding operation, and the operation start time in the next overshoot specified value Ds region is reached. At Tn, the work holding operation can be executed. That is, it means that the tact time is substantially increased, and the time until the work holding device 70 starts the holding operation of the work is increased, and the cycle time is lowered, that is, the productivity is lowered. Therefore, in the case of the motion trajectory F2 as shown in FIG. 6C, the work is held from the tact time Tc that is equal to or less than the tact time specified value Ts by adjusting the overshoot Dc closer to the overshoot Ds. The operation, that is, the operation of the work holding device 70 can be started. Specifically, the overshoot Db can be reduced by reducing the gain in Kvi 620a. The gain adjustment in Kvi 620a is preferably executed with an adjustment width of 2% in one adjustment operation.

  As illustrated in FIG. 3, the robot apparatus 100 may include a display unit 700. The display unit 700 includes the movement trajectories F0, F1, and F2 shown in FIG. 6 of the mounting position P calculated by the fourth calculation unit, specific overshoots Da, Db, and Dc, or tact times Ta, Tb, and Tc. The information can be displayed to the operator by displaying the numerical value of the value, displaying the numerical value of the gain in Kvi 620a by the control unit 600, and further displaying the abnormality when the adjustment range is exceeded.

  In the robot apparatus 100 according to the present embodiment described above, the overshoot and tact time within the initially set overshoot specified value Ds and the tact time specified value Ts shift as the operating time elapses, and overshoot specified. Even when the value Ds or the tact time specified value Ts is deviated, the robot apparatus 100 is operated within the overshoot specified value Ds and the tact time specified value Ts by increasing or decreasing the gain in the speed loop integral gain Kvi 620a. The stability of the operation and the productivity can be maintained at the initial performance for a long time. In addition, since predetermined display contents can be displayed on the display unit 700 by the display process, it is possible to control the driving of the robot apparatus 100 based on the operator's judgment, and the safety can be further enhanced.

(Second Embodiment)
As a second embodiment, a control method of the robot apparatus 100 according to the first embodiment will be described. FIG. 7 is a flowchart showing a control method of the robot apparatus 100.

[First calculation step]
In the operating state of the robot apparatus 100, the first calculation step (S111) is first executed. In the first calculation step (S111), rotation angle data is obtained from the angle sensors 81 and 82 provided in the actuators 51 and 52 in the first calculation unit 510. The obtained rotation angle data is converted into a rotation angle, the rotation angle is differentiated once with respect to time, the rotation angular velocity ω1 of the output portion of the arm coupling device 20 including the actuator 51 that drives the second arm 12, the base body coupling The rotational angular velocity ω2 of the output unit of the device 30 is calculated.

[Second calculation step]
At the same time, in the second calculation step (S112), the angular velocity data is obtained from the inertial sensor 90 provided in the second arm 12 in the second calculation unit 520, and the connecting devices 20 and 30 for connecting and driving the arm body 10 are used as the rotation axes. The angular velocities of the arms 11 and 12 are calculated. That is, the angular velocity ω _a at the position where the inertial sensor 90 of the arm body 10 having the base body coupling device 30 as the rotation axis is calculated from the data obtained from the inertial sensor 90 as described above.

[Third calculation step]
Next, the process proceeds to the third calculation step (S120). In the third calculation step (S120), the angular velocity ω1, ω2 calculated in the first calculation step (S111) and the angular velocity ω of the arm body 10 calculated from the detection data of the inertial sensor 90 in the second calculation step (S112). _{From a}
ω _b = ω _a −ω2−ω1
To calculate the torsional angular velocity ω _b . The calculated torsional angular velocity ω _b is filtered by a bandpass filter, and the torsional angular velocity ω _b1 of the first arm 11 and the torsional angular velocity ω _b2 of the second arm 12 are extracted and calculated.

[Fourth calculation step]
Next, the process proceeds to the fourth calculation step (S130). In the fourth calculation step (S130), the torsion angular velocity ω _b1 component of the first arm 11 and the torsion angular velocity ω _b2 component of the second arm 12 calculated in the third calculation step (S120) are integrated and attached. The vibration shown in FIG. 1 at the position P (see FIG. 2) is calculated, and the overshoot is calculated. Based on the result, the process proceeds to an integral gain adjustment step (S140) as a control step. In the fourth calculation step (S130), the tact time is also acquired.

[Integral gain adjustment process]
The integral gain adjustment step (S140) as a control step is configured by a flowchart shown in FIG. In the integral gain adjustment step (S140), the control unit 600 integrates Kvi 620a (see FIG. 5) based on the overshoot (hereinafter referred to as overshoot D) that is the calculation result in the fourth calculation step (S130) obtained. Adjust the gain.

[Quantity judgment process]
As shown in FIG. 8, from the fourth calculation step (S130), first, the quantity determination step (S210) for determining whether the work of the robot apparatus 100 has been completed, that is, whether the work piece inputted in advance has reached a predetermined quantity. It is transferred to. If it is determined in the quantity determination step (S210) that the planned quantity has been reached (YES), the process proceeds to a robot apparatus stop confirmation step (S150) described later. If it is determined in S210 that the planned quantity has not been reached (NO), the process proceeds to the next specified value reading process (S220).

[Default value reading process]
In the specified value reading step (S220), the overshoot specified value Ds and the tact time specified value Ts determined in advance as specifications or request criteria are read into the control unit 600. The overshoot specified value Ds and the tact time Ts can be written in the RAM 400 in advance, or can be input and stored in the ROM 300 by input means, and can be read and read from the RAM 400 or the ROM 300. Further, it may be input directly to the control unit 600 by input means. Next, the process proceeds to an overshoot comparison step (S230) as a comparison step for comparing the overshoot D calculated in the fourth calculation step (S130) with the overshoot specified value Ds.

[Overshoot comparison process]
In the overshoot comparison step (S230) as the comparison step, it is determined whether or not the overshoot D is within the overshoot specified value Ds. In the overshoot comparison step (S230), when it is determined that the overshoot D is within the overshoot specified value Ds, that is, D ≦ Ds, the process proceeds to the first tact time comparison step (S240). If it is determined that the overshoot D exceeds the overshoot specified value Ds, that is, D> Ds, the process proceeds to the second tact time comparison step (S250).

[First tact time comparison process]
In the overshoot comparison step (S230), it is determined that D ≦ Ds, and in the shifted first tact time comparison step (S240), the tact time (hereinafter referred to as tact time T) acquired until the fourth calculation step (S130). ) And the tact time prescribed value Ts read in the prescribed value reading step (S220). In the first tact time comparison step (S240), when it is determined that the tact time T is within the tact time specified value Ts, that is, T ≦ Ts, both the overshoot D and the tact time T are within the specified values Ds and Ts. Since there is no need to adjust the integral gain, the process proceeds to the next robot apparatus operation stop confirmation step (S150).

[First gain adjustment instruction step]
However, in the first tact time comparison step (S240), if the tact time T exceeds the tact time specified value Ts, that is, it is determined that T> Ts, the process proceeds to the first gain adjustment instruction step (S250). In the first gain adjustment instruction step (S250), a gain adjustment instruction is sent from the gain adjustment instruction unit 620b to the Kvi 620a so that the tact time T is reduced and within the tact time Ts. In this case, the overshoot D is within the overshoot specified value Ds, and the tact time T can be shortened by increasing the overshoot D, as shown by the operation locus F2 described with reference to FIG. it can. Therefore, in the first gain adjustment instruction step (S250), an instruction to increase the gain in Kvi 620a is issued so as to increase the overshoot D, and the Kvi 620a having the adjusted gain is obtained, and the process proceeds to the test operation step (S260). As the adjustment amount at this time, it is preferable to increase the gain by about 5%.

[Test operation process]
In the test operation step (S260), the robot apparatus 100 is test-driven by the Kvi 620a having the adjusted gain, and the first calculation step (S111), the second calculation step (S112), the third calculation step (S120), The fourth calculation step (S130) is executed, the adjusted overshoot D 'and the tact time T' are calculated and measured, the process proceeds to the overshoot comparison step (S230) again, and the overshoot comparison step (S230) is performed. ) The subsequent steps are executed. At this time, the overshoot D ′ is rewritten to the overshoot D and the tact time T ′ is rewritten to the tact time T, respectively.

[Second tact time comparison process]
In the above description, the case of D ≦ Ds in the overshoot comparison step (S230) has been described. However, in the following, in the overshoot comparison step (S230), the overshoot D exceeds the overshoot specified value Ds, that is, D> Ds. The case of will be described. If it is determined that D> Ds in the overshoot comparison step (S230), the process proceeds to the second tact time comparison step (S270). In the second tact time comparison step (S270), the tact time T and the tact time specified value Ts are compared as in the first tact time comparison step (S240).

  In the second tact time comparison step (S270), when it is determined that the tact time T is within the tact time specified value Ts, that is, T ≦ Ts, the process proceeds to the second gain adjustment instruction step (S280). In the second gain adjustment instruction step (S280), since the tact time T is within the tact time specified value Ts, the overshoot D determined as D> Ds in the overshoot comparison step (S230) is changed to the overshoot specified value Ds. The instruction to lower the gain in Kvi 620a is issued so that the Kvi 620a has an adjusted gain, and the process proceeds to the test operation step (S260). As an adjustment amount at this time, it is preferable to lower the gain by about 5%.

[Operation stop]
However, in the second tact time comparison step (S270), when the tact time T exceeds the tact time specified value Ts, that is, it is determined that T> Ts, the operation shifts to the operation stop (S300) and the robot apparatus 100 operates. Is stopped, and the display unit 700 displays the display content indicating the operation stop. That is, in order to shorten the tact time T, the tact time T can be shortened by increasing the overshoot D as shown by the operation locus F2 described in FIG. Since it is determined that D> Ds in the shoot comparison step (S230), there is no gain adjustment range in Kvi 620a that can increase the overshoot D, so the robot apparatus 100 is stopped.

  As described above, in the integral gain adjustment step (S140), the gain of Kvi 620a is adjusted in one adjustment so that the overshoot D and the tact time T are in the range of the overshoot specified value Ds and the tact time specified value Ts. Is increased or decreased by 5% to be adjusted to the prescribed values Ds and Ts, and the process proceeds to the next robot apparatus stop confirmation step (S150). The integral gain adjustment step (S140) includes a display step (not shown) for displaying overshoot D, tact time T, overshoot specified value Ds, tact time Ts, operation stop information, etc. Information is displayed.

[Robot device stop confirmation process]
In the robot apparatus operation stop confirmation step (S150), it is confirmed whether the robot apparatus 100 is in an operation state. If the robot apparatus 100 is in an operation state (No), the first operation step (S111) and the second operation step (S112). Return to) and repeat the control. If the operation is stopped (Yes), the control ends.

  By the above-described control method, the robot apparatus 100 causes the overshoot and tact time within the initially set overshoot specified value Ds and the tact time specified value Ts to shift as the operating time elapses and the overshoot specified value Ds. Alternatively, the robot apparatus 100 is operated within the overshoot specified value Ds and the tact time specified value Ts over a long period of time by increasing or decreasing the speed loop integral gain Kvi even if the state deviates from the tact time specified value Ts. The stability of the operation and the productivity can be maintained at the initial performance. In addition, since predetermined display contents can be displayed on the display unit 700 by the display process, it is possible to control the driving of the robot apparatus 100 based on the operator's judgment, and the safety can be further enhanced.

  In the control method of the robot apparatus 100 described above, only the overshoot can be compared and determined to adjust the integral gain. In that case, the first tact time comparison step (S240) and the second tact time comparison step (S270) can be omitted. In the control method of the robot apparatus 100 according to the above-described embodiment, the same effect can be obtained by adjusting the proportional gain of the position loop like the integral gain of the speed loop.

  DESCRIPTION OF SYMBOLS 10 ... Arm body, 11, 12 ... Arm, 20 ... Arm coupling device, 30 ... Base body coupling device, 40 ... Base body, 51, 52 ... Actuator, 61, 62 ... Torque transmission device, 70 ... Work holding device, 81, 82 ... An angle sensor, 90 ... Inertia sensor, 100 ... Robot device.

Claims (6)

An arm coupling device including an actuator and an angle sensor for detecting a rotation angle of the actuator;
A plurality of arms connected in series and rotatably by the arm connecting device;
A base body in which the arm body is rotatably connected by a base body connecting device including the actuator provided at one end of the arm body and an angle sensor for detecting a rotation angle of the actuator;
Among the plurality of arms, an inertial sensor including at least an angular velocity sensor is provided at an attachment position of the work arm to which the work piece holding means is attached.
A first calculator that calculates an angular velocity of the arm from rotation angle detection data of the angle sensor;
A second calculator that calculates an angular velocity at the mounting position of the work arm from the angular velocity detection data of the inertia sensor;
A torsional angular velocity between the actuator and the arm connected to the actuator is calculated from a difference between the angular velocity of the arm and the angular velocity of the arm calculated based on the angular velocity detection data of the inertial sensor. A third computing unit;
A fourth calculation unit for calculating an overshoot of the working arm from the twist angular velocity;
A control unit that includes a comparison unit that compares the overshoot and the overshoot specified value of the working arm, and a controller that increases or decreases a speed loop integral gain according to an overshoot comparison result of the comparison unit;
A robot apparatus characterized by that. The comparison unit compares the tact time of the working arm with a tact time specified value, and increases or decreases the speed loop integral gain according to the overshoot comparison result and the tact time comparison result.
The robot apparatus according to claim 1. An external display means for displaying the overshoot calculated by the fourth calculation unit and the result of the tact time;
The robot apparatus according to claim 1 or 2, wherein An arm coupling device including an actuator and an angle sensor for detecting a rotation angle of the actuator;
A plurality of arms connected in series and rotatably by the arm connecting device;
A base body in which the arm body is rotatably connected by a base body connecting device including the actuator provided at one end of the arm body and an angle sensor for detecting a rotation angle of the actuator;
A control method of a robot apparatus comprising: an inertial sensor including at least an angular velocity sensor at an attachment position of the work arm to which the work piece holding means is attached among the plurality of arms. Because
A first calculation step of calculating an angular velocity of the arm from rotation angle detection data of the angle sensor;
A second calculation step of calculating an angular velocity at the mounting position of the work arm from the angular velocity detection data of the inertia sensor;
A torsional angular velocity between the actuator and the arm connected to the actuator is calculated from a difference between the angular velocity of the arm and the angular velocity of the arm calculated based on the angular velocity detection data of the inertial sensor. A third calculation step;
A fourth calculation step of calculating an overshoot of the working arm from the twist angular velocity;
A comparison step of comparing the overshoot of the working arm with a specified overshoot value;
A control step of increasing or decreasing the speed loop integral gain according to the overshoot comparison result of the comparison means,
A method for controlling a robot apparatus, comprising: The comparison step compares the tact time of the working arm with a tact time specified value, and increases or decreases the speed loop integral gain according to the overshoot comparison result and the tact time comparison result.
The robot apparatus control method according to claim 4, wherein: An external display step of displaying the overshoot calculated by the fourth calculation step and the result of the tact time;
The method for controlling a robot apparatus according to claim 4 or 5, wherein

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