WO2023007574A1

WO2023007574A1 - Robot control device and robot control method

Info

Publication number: WO2023007574A1
Application number: PCT/JP2021/027680
Authority: WO
Inventors: 卓矢岡原; 浩司白土
Original assignee: 三菱電機株式会社
Priority date: 2021-07-27
Filing date: 2021-07-27
Publication date: 2023-02-02
Also published as: JP2023030226A; JPWO2023007574A1

Abstract

A robot control device (1, 1a, 1b) provided with: a command value candidate generation unit (12, 12b) that generates a command value candidate for a robot (10) on the basis of an operation program configured using a pre-generated operation path of the robot (10) and on the basis of a previous command value previously output to the robot (10) or operation information of the robot (10); a command value candidate correction unit (14) that corrects the command value candidate on the basis of an external correction amount associated with a change in the operation path and uses the same as a corrected command value candidate; a corrected operation path determination unit (16, 16b) that determines whether or not the robot (10) can perform operation on a corrected operation path passing through the corrected command value candidate and outputs the determination result; and a command value output unit (17, 17a) that calculates a command value for the robot (10) using the command value candidate or the corrected command value candidate on the basis of the determination result and outputs the command value.

Description

ROBOT CONTROL DEVICE AND ROBOT CONTROL METHOD

The present disclosure relates to a robot control device and a robot control method for correcting the motion of a robot based on an external sensor or the like.

In general, a robot control device presets a target position and operates the robot according to a motion program composed of a motion path passing through the motion start position and the target position. This is called teaching playback control. In teaching playback control, if there is an error between the preset target position and the actual target position to be reached, the robot may not be able to perform correct movements and may stop due to an error. In order to solve this problem, there is a method of correcting the motion path based on the image data acquired from the imaging device. This is called visual feedback control. Note that the image data includes a target position to be actually reached.

Patent Document 1 discloses a robot control device that realizes visual feedback control. First, the robot controller generates a first command value according to a preset operation program. Next, the robot controller generates a second command value based on the image of the robot at the current position and the image of the robot at the target position to be reached. Next, the robot control device calculates a command value by adding each of the first command value and the second command value with a predetermined weight. Finally, the robot controller operates the robot according to the calculated command value.

JP 2015-74061 A

In Patent Document 1, there are cases where the robot interferes with the surrounding environment because the motion path passing through the superimposed command values deviates from the motion path determined by the motion program. In order to prevent this, it is necessary to stop the robot urgently, and there is a problem that recovery work takes time.

The present disclosure has been made to solve the above-described problems, and provides a robot control device and a robot control method that minimize emergency stoppages of a robot even when the motion of the robot is corrected based on an external sensor. for the purpose.

A robot control apparatus according to the present disclosure provides a motion program configured with a pre-generated motion path of a robot, and based on a previous command value output to the robot last time or motion information of the robot, to the robot. a command value candidate generating unit for generating a command value candidate of, a command value candidate correcting unit for correcting the command value candidate to be a post-correction command value candidate based on the external correction amount accompanying the change of the motion path; a corrected motion path determination unit for determining whether the robot is operable or inoperable with respect to a corrected motion path passing through the corrected command value candidates and outputting a determination result; a command value output unit that calculates a command value for the robot using the value candidate or the corrected command value candidate, and outputs the command value.

Further, the robot control method according to the present disclosure is based on an operation program including a pre-generated robot operation path and a previous command value output to the robot last time or operation information of the robot. a step of generating a command value candidate for a robot; a step of correcting the command value candidate to a post-correction command value candidate based on an external correction amount associated with a change in the motion path; a step of determining whether the modified motion path passing through is operable or inoperable and outputting a determination result; and based on the determination result, using the command value candidate or the corrected command value candidate to the robot and calculating a command value of and outputting the command value

According to the present disclosure, the robot control device and the robot control method can minimize emergency stops of the robot even when the motion of the robot is corrected based on the external sensor.

3 is a diagram showing a hardware configuration of a robot control device according to Embodiments 1 to 3; FIG. 1 is a block diagram showing an example of a robot control device according to Embodiment 1; FIG. 4 is a block diagram showing an example of a command value candidate generating section in

Embodiments

1 and 2; FIG. FIG. 4 is a schematic diagram showing an example of the motion of the robot in Embodiments 1 to 3; 4 is a flow chart showing an example of the operation of the robot control device according to Embodiment 1; 4 is a flow chart showing an example of the operation of a command value candidate generation unit in

Embodiments

1 and 2; 7 is a flow chart showing an example of the operation of a post-correction motion path calculator in

Embodiments

1 and 2; 7 is a flow chart showing an example of the operation of a post-correction motion path determining unit in

Embodiments

1 and 2; FIG. 10 is a block diagram showing an example of a robot control device according to Embodiment 2; FIG. FIG. 10 is a block diagram showing an example of a command value output section in Embodiment 2; FIG. FIG. 10 is a schematic diagram showing an example of the motion of the robot in Embodiment 2; 9 is a flow chart showing an example of the operation of the robot control device according to Embodiment 2; 9 is a flow chart showing an example of the operation of a command value output unit according to Embodiment 2; 10 is a flow chart showing another example of the operation of the command value output unit according to Embodiment 2; FIG. 11 is a block diagram showing an example of a robot control device according to Embodiment 3; FIG. 11 is a block diagram showing an example of a command value candidate generation unit according to Embodiment 3; FIG. 12 is a schematic diagram showing an example of the motion of the robot in Embodiment 3; 14 is a flow chart showing an example of the operation of the robot control device according to Embodiment 3; FIG. 11 is a flow chart showing an example of the operation of a post-correction motion path determination unit according to Embodiment 3. FIG. 14 is a flow chart showing an example of the operation of a command value candidate generation unit according to Embodiment 3;

Embodiment 1.
FIG. 1 is a diagram showing a hardware configuration of a robot control device 1 according to Embodiment 1. As shown in FIG. A robot control device 1 is a device for controlling a robot 10, and includes a CPU (Central Processing Unit) 2 that operates to control the robot 10, and a storage device 3 that stores data used when the CPU 2 operates. , and an IO (Input Output) interface 4 . The robot control device 1 will be described later in detail with reference to FIG.

The CPU 2 controls the robot 10 by implementing the functions of each part of the robot control device 1 using software (software, firmware, or software and firmware). CPU2 is an example of a processor. Therefore, the control of the robot 10 is not limited to the CPU 2, and may be, for example, a microprocessor, a microcomputer, or a DSP (Digital Signal Processor).

The storage device 3 stores data indicating the housing model of the robot 10 , data indicating the position and orientation of the hand (not shown) of the robot 10 , and an operation program for the robot 10 . The motion program consists of a pre-generated motion path of the robot 10 , and this motion path includes at least the motion start position and the target position of the robot 10 . Alternatively, based on the housing model of the robot 10, a motion path obtained by converting the position and posture of the hand at the motion start position into joint angles and a motion path obtained by converting the position and posture of the hand at the target position into joint angles are used as the motion program. may be configured in this motion path. The storage device 3 is, for example, a ROM (Read Only Memory), a HDD (Hard Disk Drive), or a RAM (Random Access Memory).

The IO interface 4 outputs signals to the receiving device 6 . The receiving device 6 is, for example, a lamp or a buzzer that notifies the operating state of the robot 10 to the outside. The signal output to the receiving device 6 is, for example, an instruction command for notifying the operating state of the robot 10 to the outside. The IO interface 4 inputs a signal from the input device 7 . The input device 7 is, for example, an external sensor such as a light curtain, an area sensor or an imaging device. The signal from the input device 7 is, for example, the position of the surrounding environment detected from the image acquired by the input device 7 . The surrounding environment is, for example, obstacles such as safety fences, work benches, or work jigs around the robot 10 . Also, the surrounding environment may refer to the imaging device itself. The position of the surrounding environment is acquired by, for example, geometric information or point group information. The geometric information is CAD (Computer Aided Design) data of the surrounding environment, and cylinders, cuboids, and the like that contain the surrounding environment. The point group information is information obtained when the input device 7 is an RGB-D (Red Green Blue-Depth) sensor or a LiDAR (Light Detection and Ranging) sensor.

The robot 10 has a plurality of arms (not shown) and a hand provided at the tip of each arm. Each arm is connected to the main body of the robot 10 so as to be rotatable about the connecting portion of the adjacent arm. Also, a portion where the main body of the robot 10 and the arm are connected is defined as a joint portion. The robot 10 has one or more joints. Moreover, each joint part is provided with a driving device (not shown) for changing the joint angle. The robot control device 1 can control the position and posture of the hand by controlling the driving device. Note that the connecting portion can also be provided with a driving device like the joint portion, and the driving device can change the rotation angle of the connecting portion. Therefore, hereinafter, the connection portion and the joint portion will be collectively referred to as the joint portion. The driving device may be, for example, an electric motor typified by a servomotor or a stepping motor, or a cylinder using pneumatic pressure or hydraulic pressure, but is not limited to these.

The joint is equipped with a joint angle measuring device (not shown). The joint angle measuring device is, for example, an encoder or imaging device. When the joint angle measuring device is an imaging device, the joint angle can be obtained using an image acquired by the imaging device. Alternatively, on the premise that the robot 10 follows the command value without error, the command value itself in each control cycle stored by the storage device 3 may be used as the joint angle. Here, the command value is the joint angle transmitted from the IO interface 4 to the robot 10, or the position and posture of the hand. If the command value is the position and orientation of the hand, it is necessary to convert the position and orientation of the hand into joint angles based on the housing model of the robot 10 stored in the storage device 3 . Hereinafter, command values are described as joint angles unless otherwise specified. That is, the information input and output between each component of the robot control device 1 is information regarding joint angles.

FIG. 2 is a block diagram showing an example of the robot control device 1 according to the first embodiment. As shown in FIG. 2, the robot control device 1 includes an operation program storage unit 11, a command value candidate generation unit 12, an external correction amount acquisition unit 13, a command value candidate correction unit 14, and a post-correction motion path calculation unit. 15 , a post-correction motion path determination unit 16 , and a command value output unit 17 . FIG. 2 is a block diagram when the robot control device 1 controls the robot 10 in a certain control period. The robot control device 1 outputs command values to the robot 10 at predetermined control cycles. A command value is a joint angle output to a driving device corresponding to one or more joints. Therefore, the command value is composed of one or more joint angles. The robot 10 drives a plurality of arms of the robot 10 by inputting joint angles from the robot control device 1 .

The motion program storage unit 11 is a part of the storage device 3 and stores one or more data indicating the position and orientation of the hand of the robot 10 and the motion program of the robot 10 . The operation program may be set in advance by the operator before the robot operates. At this time, it is desirable that the motion path constituting the motion program is generated so that the robot 10 does not interfere with the surrounding environment.

The command value candidate generation unit 12 generates command value candidates for the robot 10 based on the operation program from the operation program storage unit 11 and the previous command value output to the robot 10 last time. Alternatively, the command value candidate generator 12 generates command value candidates based on the motion program and the motion information of the robot 10 . The previous command value is a command value output from the command value output unit 17 to the robot 10 in the previous control cycle starting from a certain control cycle. The motion information of the robot 10 is information acquired by the joint angle measuring device of the joint of the robot, and is information acquired at the timing when the command value candidate generation unit 12 generates command value candidates. The command value candidate generator 12 will be described later in detail with reference to FIG.

The external correction amount acquisition unit 13 acquires the external correction amount associated with the change of the motion path, particularly the target position, stored in the motion program storage unit 11 . That is, the external correction amount acquisition unit 13 acquires the external correction amount used by the robot control device 1 to correct the command value candidate when the target position is changed during operation of the robot 10 . The target position is changed when there is an error between the preset target position and the target position to be actually reached, and when the preset target position itself is changed. The latter is, for example, the case where the container is moved by a belt conveyor or the like when storing the parts gripped by the robot 10 in the container. In this case, the target position, that is, the position of the container, is changed during operation of the robot 10 . The amount of external correction is calculated based on an image of the robot in a certain control cycle acquired by an external sensor such as an imaging device and an image of the robot at the target position to be reached. Specifically, the external correction amount is calculated based on the position of the robot and the position of the target position to be reached in a certain control cycle, obtained from the image. The external correction amount is not the difference between the two positions itself, but a value with a certain step size for the difference between the two positions. That is, the external correction amount is a value that gradually reduces the difference between the two positions. The external correction amount may be the same value in each control cycle, or may be a different value.

As a method of calculating the amount of external correction, an example of using an image acquired by an imaging device was given, but it is not limited to this. As an example, a LiDAR may be used instead of the imaging device, and the external correction amount may be calculated using the point cloud information of the robot 10 acquired by the LiDAR. Also, the external correction amount acquisition unit 13 acquires an external correction amount calculated outside the robot control device 1, but is not limited to this. The external correction amount acquisition unit 13 may have a function of calculating as well as acquiring the external correction amount. When the external correction amount is a correction amount relating to the position and orientation of the hand of the robot 10, the external correction amount acquisition unit 13 converts the position and orientation of the hand into joint angles.

The command value candidate correction unit 14 corrects the command value candidate from the command value candidate generation unit 12 based on the external correction amount from the external correction amount acquisition unit 13, and uses this as a post-correction command value candidate.

The post-correction motion path calculation unit 15 calculates a post-correction motion path passing through the post-correction command value candidates from the command value candidate correction unit 14 . A method for calculating the modified motion path will be described later in detail.

The post-correction motion path determination unit 16 determines whether the robot 10 is operable or inoperable with respect to the post-correction motion path from the post-correction motion path calculation unit 15, and outputs the determination result. If the robot 10 can follow the corrected motion path, the corrected motion path determining unit 16 determines that the robot 10 can move. There are static determination and dynamic determination for determining whether or not the robot 10 can follow. The static determination is, for example, a determination as to whether or not the robot 10 can move on the post-correction motion path within the physical movable range of the joint angles. In addition, the static determination is, for example, whether the robot 10 can move on the corrected motion path without interfering with the surrounding environment, or whether the robot 10 can move on the modified motion path within the set work space. It is a judgment of no. Dynamic determination is, for example, a determination as to whether or not the robot 10 can move on the corrected motion path within a predetermined period of time. This corresponds to determining whether or not the angular velocity and angular acceleration of the joints required for moving on the modified motion path are equal to or less than the upper limit values of the angular velocity and angular acceleration of the joints that the robot 10 can output. .

The command value output unit 17 uses the command value candidate from the command value candidate generation unit 12 or the corrected command value candidate from the command value candidate correction unit 14 based on the determination result from the corrected operation path determination unit 16. A command value to the robot 10 is calculated using the controller 10, and the command value is output. In the first embodiment, the command value output unit 17 uses the corrected command value candidate as the command value when the determination result is operable, and commands the command value candidate when the determination result is inoperable. value.

FIG. 3 is a block diagram showing an example of the command value candidate generator 12 according to the first embodiment. The command value candidate generation unit 12 includes an interpolation point setting unit 121 , a previous interpolation point holding unit 122 , a relative value calculation unit 123 , and a command value candidate calculation unit 124 .

The interpolation point setting unit 121 sets an interpolation point J(k) in a certain control cycle k among the interpolation points passing through the operation path from the operation program storage unit 11 . However, k is k≧0, and is an integer that is incremented according to the number of command value outputs from the start of the robot 10 operation. Further, although k originally indicates an index of the control period, hereinafter, it is simply described as "control period" for the sake of simplification. When the control period k is 0, it means that the robot 10 is set at the motion start position, and the command value is output in advance as the motion start position. Therefore, it is treated as k>0 hereinafter. The interpolation point J(k) is the joint angle of the robot 10 assuming that the external correction amount from the external correction amount acquisition unit 13 is always zero. The interpolation point J(k) is desirably set so that the angular velocity and angular acceleration of the joint are equal to or less than different predetermined values. This predetermined value is a value having a likelihood (for example, 80%) with respect to the upper limit values of joint angular velocities and angular accelerations that can be output by the robot 10 .

The previous interpolation point holding unit 122 holds the previous interpolation point J(k-1) in the control cycle (k-1) one before a certain control cycle k.

The relative value calculation unit 123 calculates a relative value in a certain control cycle k based on the interpolation point J(k) from the interpolation point setting unit 121 and the interpolation point J(k−1) from the previous interpolation point holding unit 122. Compute dJ(k). The relative value dJ(k) is given by Equation (1) below.

However, n is n≧1 and is an integer indicating the control cycle at the target position of the movement path.

The command value candidate calculation unit 124 outputs the command value J ₀ (k−1) in the previous control period (k−1) from the command value output unit 17, the relative value dJ(k) from the relative value calculation unit 123, and A command value candidate J _p (k) in a certain control cycle k is calculated based on . The command value candidate J _p (k) is given by Equation (2) below. Note that the motion information of the robot 10 may be J ₀ (k−1) instead of the command value in the previous control cycle (k−1).

Next, a method for the post-correction motion path calculation unit 15 to calculate the post-correction motion path will be described. The calculation method differs according to the magnitude of the control period k and the control period n at the target position. When k>n, the post-correction motion path calculation unit 15 directly sets the post-correction command value candidate from the command value candidate correction unit 14 as the post-correction motion path. When k≦n, the post-correction motion path calculation unit 15 calculates the post-correction motion path by the following method.

First, the post-correction motion path calculation unit 15 defines a motion path T(k) from a certain control cycle k to a control cycle n at the target position, passing through the command value candidates, as shown in Equation (3) below.

The post-correction motion path calculation unit 15 sets the interpolation point after the control cycle (k+1) and calculates the relative value using the formula (1), thereby obtaining the motion path T(k) shown in the formula (3). set. Next, the post-correction motion path calculation unit 15 defines a motion path difference dT(k) from a given control cycle k to a control cycle n up to the target position as shown in Equation (4) below.

Finally, the post-correction motion path calculation unit 15 passes through the post-correction command value candidate J _m (k) and calculates the post-correction motion path T _m (k) from a certain control cycle k to the control cycle n at the target position as follows: is defined as in Equation (5).

From the equations (3) and (5), the modified motion path T _m (k) is the modified command value candidate J _m (k) and the motion path T (k) passing through the command value candidate J (k). It is the difference (J _m (k)-J(k)) from the command value candidate J(k).

4(a) to (c) are schematic diagrams showing an example of the motion of the robot 10 according to the first embodiment. FIGS. 4A to 4C show the robot 10 when the target position is changed to GLb while the robot 10 is moving from the motion start position ST toward the target position GLa along the preset motion path Ra. 10 shows the operation of FIG. FIG. 4(a) is a diagram showing the operation of the robot 10 when the surrounding environment SO does not exist around the robot 10. FIG. 4(b) and 4(c) are diagrams showing the motion of the robot 10 when the surrounding environment SO exists. 4(a) to 4(c), the position of the hand of the robot 10 is used as the command value instead of the joint angle of the robot 10, in order to describe the operation of the robot 10 in an easy-to-understand conceptual diagram. This also applies to later FIGS. 11 and 17. FIG.

As shown in FIG. 4(a), when the control cycle is 0, the operator or the robot control device 1 sets the hand of the robot 10 to the motion start position ST. In control cycle 1, the command value candidate generator 12 sets an interpolation point P1 on the motion path Ra. The command value output unit 17 outputs to the robot 10 a command value corresponding to the interpolation point P1.

Assume that the target position GLa is changed to GLb in control cycle 2. In this case, the command value candidate generation unit 12 sets an interpolation point P2 on the motion path Ra and uses this as a command value candidate. Further, the command value candidate correction unit 14 corrects the command value candidate P2 from the command value candidate generation unit 12 based on the external correction amount from the external correction amount acquisition unit 13, and sets the corrected command value candidate P21. . The external correction amount from the external correction amount acquisition unit 13 in control cycle 2 corresponds to the difference between the post-correction command value candidate P21 and the command value candidate P2. Next, the corrected motion path calculator 15 sets interpolation points P3, P4, . . . on the motion path Ra. Based on the interpolation points P3, P4, . . . Calculate a modified motion path R1 passing through . Next, the corrected motion path determination unit 16 determines whether the robot 10 can move the corrected command value candidates P21, positions P31, P41, . . . judge. As shown in FIG. 4A, the surrounding environment SO does not exist on the post-correction motion path R1. It is also assumed that the angular velocity and angular acceleration of the joints required for moving along the corrected motion path R1 are equal to or less than the upper limit values of the angular velocity and angular acceleration of the joints that the robot 10 can output. In this case, the corrected motion path determination unit 16 determines that the robot 10 is operable. The command value output unit 17 outputs to the robot 10 a command value corresponding to the post-correction command value candidate P21.

In control cycle 3, the command value candidate generation unit 12 generates a command value candidate P31 based on the difference between the interpolation point P3 and the interpolation point P2 and the previous command value P21. Further, the command value candidate correction unit 14 corrects the command value candidate P31 from the command value candidate generation unit 12 based on the external correction amount from the external correction amount acquisition unit 13, and sets the command value candidate after correction P32. . The external correction amount in control cycle 3 corresponds to the difference between the post-correction command value candidate P32 and the command value candidate P31. Next, the post-correction motion path calculator 15 sets positions P42, . . . based on the positions P41, . A corrected motion path R2 passing through is calculated. Next, the corrected motion path determination unit 16 determines whether the robot 10 can move the corrected command value candidate P32, the position P42, . . . do. As shown in FIG. 4A, the surrounding environment SO does not exist on the post-correction motion route R2. It is also assumed that the angular velocity and angular acceleration of the joints required for moving along the corrected motion path R2 are equal to or less than the upper limit values of the angular velocity and angular acceleration of the joints that the robot 10 can output. In this case, the corrected motion path determination unit 16 determines that the robot 10 is operable. The command value output unit 17 outputs to the robot 10 a command value corresponding to the post-correction command value candidate P32.

In control cycle 4, the command value candidate generator 12 generates a command value candidate P42 based on the difference between the interpolation point P4 and the interpolation point P3 and the previous command value P32. Since the motion path R2 passing through the command value candidate P42 passes through the changed target position GLb, the external correction amount in the control cycle 4 becomes zero. Therefore, after control period 4, the robot 10 operates on the motion route R2 passing through the command value candidate P42.

In the case of FIG. 4(a), the robot 10 is controlled to pass through the motion start position ST, position P1, position P21, position P32, position P42, .

As shown in FIG. 4(b), when the control period is 0, the operator or the robot control device 1 sets the hand of the robot 10 to the motion start position ST. In control cycle 1, the command value candidate generator 12 sets an interpolation point P1 on the motion path Ra. The command value output unit 17 outputs to the robot 10 a command value corresponding to the interpolation point P1.

Assume that the target position GLa is changed to GLb in control cycle 2. In this case, the command value candidate generation unit 12 sets an interpolation point P2 on the motion path Ra and uses this as a command value candidate. Further, the command value candidate correction unit 14 corrects the command value candidate P2 from the command value candidate generation unit 12 based on the external correction amount from the external correction amount acquisition unit 13, and sets the corrected command value candidate P21. . The external correction amount from the external correction amount acquisition unit 13 in control cycle 2 corresponds to the difference between the post-correction command value candidate P21 and the command value candidate P2. Next, the corrected motion path calculator 15 sets interpolation points P3, P4, . . . on the motion path Ra. Based on the interpolation points P3, P4, . . . Calculate a modified motion path R1 passing through . Next, the corrected motion path determination unit 16 determines whether the robot 10 can move the corrected command value candidates P21, positions P31, P41, . . . judge. As shown in FIG. 4(b), the surrounding environment SO exists on the corrected motion path R1. In this case, the corrected motion path determining unit 16 determines that the robot 10 cannot move. The command value output unit 17 outputs to the robot 10 a command value corresponding to the command value candidate P2.

In control cycle 3, the command value candidate generation unit 12 sets the interpolation point P3 as a command value candidate. Further, the command value candidate correction unit 14 corrects the command value candidate P3 from the command value candidate generation unit 12 based on the external correction amount from the external correction amount acquisition unit 13, and sets the corrected command value candidate P31. . The external correction amount in control cycle 3 corresponds to the difference between the post-correction command value candidate P31 and the command value candidate P3. Next, the post-correction motion path calculator 15 sets positions P41, . . . based on the interpolation points P4, . Compute a modified motion path R1 through . Next, the corrected motion path determining unit 16 determines whether the robot 10 can move the corrected command value candidates P31, positions P41, . . . do. As shown in FIG. 4(b), the surrounding environment SO exists on the corrected motion path R1. In this case, the corrected motion path determining unit 16 determines that the robot 10 cannot move. The command value output unit 17 outputs to the robot 10 a command value corresponding to the command value candidate P3.

From control cycle 4 onward, the same processing as in control cycle 3 is performed. However, the post-correction motion path determining unit 16 determines that the robot 10 cannot move on the post-correction motion path R1. In the case of FIG. 4(b), the robot 10 is controlled to pass through the operation start position ST, position P1, position P2, position P3, position P4, . . . It is controlled to pass through the target position GLb.

Note that the corrected motion path calculated by the corrected motion path calculation unit 15 in the control period 2 and the corrected motion path calculated by the corrected motion path calculation unit 15 in the control period 3 are the same motion path R1. , will not necessarily be the same. This is because the external correction amount is calculated based on the position of the robot and the target position GLb in a certain control cycle, and the position of the robot differs depending on the control cycle. Therefore, even if the corrected motion path calculated by the corrected motion path calculation unit 15 in the control cycle 2 is R1, the corrected motion path calculated by the corrected motion path calculation unit 15 in the control cycle 3 is not R1. There is If it is determined that the robot 10 can operate on the corrected motion path calculated in the control cycle 3, the command value output unit 17 outputs a command value corresponding to the corrected command value candidate on the corrected motion path to the robot. 10.

As shown in FIG. 4(c), when the control period is 0, the operator or the robot control device 1 sets the hand of the robot 10 to the motion start position ST. In control cycle 1, the command value candidate generator 12 sets an interpolation point P1 on the motion path Ra. The command value output unit 17 outputs to the robot 10 a command value corresponding to the interpolation point P1.

Assume that the target position GLa is changed to GLb in control cycle 2. In this case, the command value candidate generation unit 12 sets an interpolation point P2 on the motion path Ra and uses this as a command value candidate. Further, the command value candidate correction unit 14 corrects the command value candidate P2 from the command value candidate generation unit 12 based on the external correction amount from the external correction amount acquisition unit 13, and sets the corrected command value candidate P21. . The external correction amount from the external correction amount acquisition unit 13 in control cycle 2 corresponds to the difference between the post-correction command value candidate P21 and the command value candidate P2. Next, the corrected motion path calculator 15 sets interpolation points P3, P4, . . . on the motion path Ra. Based on the interpolation points P3, P4, . . . Calculate a modified motion path R1 passing through . Next, the corrected motion path determination unit 16 determines whether the robot 10 can move the corrected command value candidates P21, positions P31, P41, . . . judge. As shown in FIG. 4(c), the surrounding environment SO does not exist on the corrected motion path R1. It is also assumed that the angular velocity and angular acceleration of the joints required for moving along the corrected motion path R1 are equal to or less than the upper limit values of the angular velocity and angular acceleration of the joints that the robot 10 can output. In this case, the corrected motion path determination unit 16 determines that the robot 10 is operable. The command value output unit 17 outputs to the robot 10 a command value corresponding to the post-correction command value candidate P21.

In control cycle 3, the command value candidate generation unit 12 generates a command value candidate P31 based on the difference between the interpolation point P3 and the interpolation point P2 and the previous command value P21. Further, the command value candidate correction unit 14 corrects the command value candidate P31 from the command value candidate generation unit 12 based on the external correction amount from the external correction amount acquisition unit 13, and sets the command value candidate after correction P32. . The external correction amount in control cycle 3 corresponds to the difference between the post-correction command value candidate P32 and the command value candidate P31. Next, the post-correction motion path calculator 15 sets positions P42, . . . based on the positions P41, . A corrected motion path R2 passing through is calculated. Next, the post-correction motion path determination unit 16 determines whether the robot 10 can move through the positions P32, P42, . . . on the post-correction motion path R2. As shown in FIG. 4(c), the surrounding environment SO exists on the post-correction motion path R2. In this case, the corrected motion path determining unit 16 determines that the robot 10 cannot move. The command value output unit 17 outputs to the robot 10 a command value corresponding to the command value candidate P31.

From control cycle 4 onward, the same processing as in control cycle 3 is performed. However, the post-correction motion path determining unit 16 determines that the robot 10 cannot move on the post-correction motion path R2. In the case of FIG. 4(c), the robot 10 is controlled to pass through the operation start position ST, position P1, position P21, position P31, position P41, . controlled to pass through

The corrected motion path calculated by the corrected motion path calculation unit 15 in the control period 3 and the corrected motion path calculated by the corrected motion path calculation unit 15 in the control period 4 are the same motion path R2. , will not necessarily be the same. This is for the same reason as described with reference to FIG. 4(b). Therefore, even if the corrected motion path calculated by the corrected motion path calculation unit 15 in the control cycle 3 is R2, the corrected motion path calculated by the corrected motion path calculation unit 15 in the control cycle 4 is not R2. There is If it is determined that the robot 10 can operate on the corrected motion path calculated in the control cycle 4, the command value output unit 17 outputs a command value corresponding to the corrected command value candidate on the corrected motion path to the robot. 10.

FIG. 5 is a flow chart showing an example of the operation of the robot control device 1 according to the first embodiment. That is, FIG. 5 is a flow chart showing an example of the robot control method according to the first embodiment.

As shown in FIG. 5, when the control of the robot 10 is started by means (not shown), the means (not shown) initializes k, which is an index of the control cycle, to 1 (step ST1).

The command value candidate generation unit 12 generates command value candidates based on an operation program configured in advance with the motion path of the robot 10 and the previous command value output to the robot 10 last time or the motion information of the robot 10. is generated (step ST2). The processing of step ST2 will be described later in detail using FIG.

The command value candidate correcting unit 14 corrects the command value candidate based on the external correction amount from the external correction amount acquisition unit 13 to obtain a post-correction command value candidate (step ST3).

The post-correction motion path calculation unit 15 calculates a post-correction motion path passing through the post-correction command value candidates (step ST4). The processing of step ST4 will be described later in detail with reference to FIG.

The post-correction motion path determination unit 16 determines whether the robot 10 is operable or inoperable with respect to the post-correction motion path, and outputs the determination result (step ST5). The processing of step ST5 will be described later in detail with reference to FIG.

The command value output unit 17 calculates a command value for the robot 10 using the command value candidate or the corrected command value candidate based on the determination result from the corrected motion path determination unit 16, and outputs the command value ( step ST6). If k>n, and if the determination result from the post-correction movement path determination unit 16 indicates that the operation is impossible, the command value output unit 17 outputs the previous command value output last time as the command value to the robot 10. set as That is, the robot 10 is stopped by means not shown. The robot control device 1 may generate a movement path for the robot 10 again from this state. Then, the robot control device 1 may perform the processing from step ST1 to step ST8 of FIG. 5 on the regenerated motion path.

Whether or not to complete the control of the robot 10 is determined by means not shown (step ST7).

If the determination in step ST7 is "Yes", the control of the robot 10 ends. If the determination in step ST7 is "No", the process proceeds to step ST8. Control of the robot ends when, for example, the robot 10 reaches the target position GLb. Alternatively, it is a case where it is determined that the robot 10 has performed an abnormal operation. This determination is made by means not shown.

If the determination in step ST7 is "No", k is incremented by means not shown (step ST8).

After the processing of step ST8 is performed, the processing of steps ST2 to ST8 is repeatedly performed until the determination of step ST7 becomes "Yes".

FIG. 6 is a flow chart showing an example of the operation of the command value candidate generator 12 according to the first embodiment. That is, FIG. 6 is a flow chart showing the details of the process of step ST2 in FIG.

As shown in FIG. 6, when command value candidate generation processing is started by command value candidate generation unit 12, interpolation point setting unit 121 sets interpolation point J(k) in a certain control cycle k (step ST21). The interpolation point setting unit 121 sets an interpolation point J(k) on the motion path forming the motion program.

The previous interpolation point holding unit 122 holds and outputs the previous interpolation point J(k-1) in the previous control cycle (k-1) (step ST22).

The relative value calculator 123 calculates the relative value dJ(k) in the control period k based on the interpolation point J(k) and the previous interpolation point J(k-1). The relative value calculator 123 calculates the relative value dJ(k) based on Equation (1) (step ST23).

Command value candidate calculation unit 124 calculates command value candidate J _p ( k) is calculated (step ST24). Command value candidate calculation unit 124 calculates command value candidate J _p (k) based on expression (2).

The command value candidate generation unit 12 ends the command value candidate generation process.

FIG. 7 is a flowchart showing an example of the operation of the post-correction motion path calculation unit 15 according to the first embodiment. That is, FIG. 7 is a flow chart showing the details of the process of step ST4 in FIG.

As shown in FIG. 7, when the post-correction motion path calculation unit 15 starts the post-correction motion path calculation process, the post-correction motion path calculation unit 15 determines whether or not k is greater than n (step ST41).

If the determination in step ST41 is "Yes", the process proceeds to step ST42. If the determination in step ST41 is "No", the process proceeds to step ST43.

If the determination in step ST41 is "Yes", the post-correction motion path calculation unit 15 directly sets the post-correction command value candidate from the command value candidate correction unit 14 as the post-correction motion path T _m (k) (step ST42). ). After the process of step ST41 is performed, the post-correction motion path calculation unit 15 ends the post-correction motion path calculation process.

If the determination in step ST41 is "No", the post-correction motion path computation unit 15 computes the motion path T(k) in a certain control cycle k based on Equation (3) (step ST43).

The post-correction motion path computation unit 15 computes the motion path difference dT(k) at a certain control cycle k based on Equation (4) (step ST44).

The post-correction motion path calculation unit 15 calculates the post-correction motion path T _m (k) in a certain control cycle k based on Equation (5) (step ST45). After the process of step ST45 is performed, the post-correction motion path calculation unit 15 ends the post-correction motion path calculation process.

FIG. 8 is a flowchart showing an example of the operation of the post-correction motion path determination unit 16 according to the first embodiment. That is, FIG. 8 is a flow chart showing the details of the process of step ST5 in FIG.

As shown in FIG. 8, when the post-correction motion path determination unit 16 starts the process of determining whether the robot 10 is operable or inoperable, the post-correction motion path determination unit 16 initializes the variable i to 0. (Step ST51). The variable i is an index of the corrected motion path T _m (k) at the control period k represented by Equation (5). For example, in Equation (5), the joint angle when i=0 is J _m (k), and the joint angle when i=1 is J _m (k)+dJ(k+1).

The post-correction motion path determining unit 16 calculates the joint angle, hand position and posture of the robot 10 corresponding to the index i of the post-correction motion path (step ST52). For example, in the modified motion path T _m (k) in Equation (5), the joint angle when i is 0 is J _m (k), and the joint angle when i is 1 is J _m (k)+dJ(k+1 ). Furthermore, in FIGS. 4A to 4C, when the post-correction command value candidate is P21, the post-correction motion path is R1. In this case, the joint angle when i is 0 is the joint angle at P21, and the joint angle when i is 1 is the joint angle at P31. The post-correction motion path determination unit 16 converts the joint angles of the robot 10 into positions and postures based on the housing model of the robot 10 .

The post-correction motion path determination unit 16 determines whether the joint angle at the index i is within the allowable range (step ST53). Specifically, the post-correction motion path determination unit 16 determines whether or not the joint angle at the index i is within the physical movable range.

If the determination in step ST53 is "Yes", the process proceeds to step ST54. If the determination in step ST41 is "No", the process proceeds to step ST55.

If the determination in step ST53 is "Yes", the post-correction motion path determination unit 16 acquires the robot housing model from the storage device 3 (step ST54). The robot housing model includes mesh information of the robot 10 as well as conversion formulas between the joint angles of the robot 10 and the hand position and posture. The robot housing model is obtained by covering the robot 10 with, for example, a plurality of triangular mesh data, and includes the triangular vertex positions of each mesh. The post-correction motion path determination unit 16 acquires this vertex position.

If the determination in step ST53 is "No", the post-correction movement path determination unit 16 determines that the determination result is inoperable (step ST55). That is, the post-correction motion path determination unit 16 determines that the joint angle at the index i cannot follow the desired joint angle, and determines that the motion cannot be performed. After the process of step ST55 is performed, the post-correction motion path determination unit 16 terminates the determination process.

Based on the vertex position acquired in step ST54, the post-correction motion path determination unit 16 determines whether the position and posture of the robot 10 at the index i are non-interfering with the surrounding environment (step ST56).

If the determination in step ST56 is "Yes", the process proceeds to step ST57. If the determination in step ST56 is "No", the process proceeds to step ST55.

If the determination in step ST56 is "Yes", the post-correction motion path determination unit 16 determines whether or not the joint angular velocity of the robot 10 at the index i is equal to or less than a predetermined value (step ST57). Alternatively, the corrected motion path determination unit 16 may also determine whether or not the joint angular acceleration of the robot 10 at the index i is equal to or less than a predetermined value. In this case, the post-correction motion path determination unit 16 determines whether the joint angular velocity of the robot 10 is equal to or less than a predetermined value, and whether the joint angular acceleration is equal to or less than a predetermined value. That is, the post-correction motion path determining unit 16 determines whether or not the angular velocity and angular acceleration of the joint obtained by the index i are equal to or less than the upper limit values of the angular velocity and angular acceleration of the joint that the robot 10 can output. When i is 0, the joint angular velocity is obtained by dividing the difference between the joint angle of the robot 10 at index 0 and the joint angle corresponding to the previous command value output in step ST6 of FIG. 5 by the control cycle. . The joint angular velocity is obtained by dividing the difference between the joint angle of the robot 10 at the index i and the joint angle at the index (i−1) by the control period when i is 1 or more. The joint angular acceleration is calculated based on the difference in joint angular velocities by a method similar to the method for calculating joint angular velocities.

If the determination in step ST57 is "Yes", the process proceeds to step ST58. If the determination in step ST56 is "No", the process proceeds to step ST55.

If the determination in step ST57 is "Yes", the post-correction motion path determination unit 16 determines whether or not all data have been determined (step ST58). That is, when k≦n, the post-correction motion path determination unit 16 determines whether or not the determinations of steps ST53, ST56, and ST57 have been performed for joint angles from a control cycle k to a control cycle n. When k>n, the corrected motion path determination unit 16 determines whether or not the determinations of steps ST53, ST56, and ST57 have been performed for the corrected motion path, that is, the corrected command value candidate. If k>n, the determination in step ST58 is "Yes" at i=0.

If the determination in step ST58 is "Yes", the process proceeds to step ST59. If the determination in step ST58 is "No", the process proceeds to step ST60.

If the determination in step ST58 is "Yes", the post-correction movement path determination unit 16 determines that the determination result is operable (step ST59). In other words, the post-correction motion path determination unit 16 determines that the joint angles of all the indices can follow the desired joint angles, and determines that the motion is possible in the determination result. After the process of step ST59 is performed, the post-correction motion path determination unit 16 ends the determination process.

If the determination in step ST58 is "No", the post-correction motion path determination unit 16 increments the variable i (step ST60). After the process of step ST60 is performed, the process proceeds to step ST52.

It should be noted that the determination procedure of steps ST53, ST56 and ST57 is not limited to the procedure shown in FIG.

According to the first embodiment described above, it is determined whether the robot 10 is operable or inoperable with respect to the corrected motion path passing through the command value candidate corrected based on the external correction amount, and based on the determination result. Since the command value to the robot 10 is calculated by using an external sensor, the emergency stop of the robot 10 can be minimized even when the operation of the robot 10 is corrected based on the external sensor.

Embodiment 2.
In the first embodiment, when it is determined that the corrected motion path passing through the corrected command value candidate is inoperable, the command value candidate is output as the command value to the robot 10 instead of the corrected command value candidate. On the other hand, in the second embodiment, even if it is determined that the motion path after correction is inoperable, the corrected command value candidate is output to the robot 10 as a command value for a certain period of time.

FIG. 9 is a block diagram showing an example of the robot control device 1a according to the second embodiment. 9 differs from FIG. 2 in that the robot control device 1a includes a command value output section 17a instead of the command value output section 17. FIG. Since the components other than the command value output unit 17a are the same as those shown in FIG. 2, description thereof will be omitted.

The command value output unit 17a outputs the corrected command value candidate from the command value candidate correction unit 14 to the robot 10 as a command value when the determination result from the corrected motion path determination unit 16 indicates that the robot is operable. When the judgment result is that the operation is impossible, the command value output unit 17a outputs the arrival time from the time when the operation is judged to be impossible to the time when the operation is actually impossible, and the command value candidates within the arrival time. Compare with the recovery time required to bring the corrected integrated value to zero. If the arrival time is longer than the restoration time, the command value output unit 17a uses the corrected command value candidate as the command value. The command value is obtained by superimposing the restored amount on the command value candidate. Alternatively, when the determination result indicates that the operation is impossible, the command value output unit 17a compares the corrected integrated value with the restoration integrated value within the arrival time of the amount of restoration calculated when the operation is determined to be impossible. do. In this case, the command value output unit 17a sets the corrected command value candidate as the command value if the restored integrated value is greater than the corrected integrated value, and if the restored integrated value is equal to or less than the corrected integrated value, sets the restoration amount. A value superimposed on the command value candidate is used as the command value. Here, the restoration amount is an amount per unit control cycle that is set so that the corrected integrated value gradually decreases to zero, and is calculated so as not to deviate from the movement restrictions of the robot 10 . A motion constraint is an upper limit value that can be output for the angular velocity and angular acceleration of the joints of the robot 10 .

FIG. 10 is a block diagram showing an example of the command value output section 17a according to the second embodiment. FIG. 10 is a block diagram when the command value output unit 17a compares the arrival time and the restoration time to calculate the command value when the determination result is that the operation is impossible. The command value output unit 17a includes a corrected integrated value calculation unit 171a, a restoration amount calculation unit 172a, and a command value calculation unit 173a.

When the determination result from the corrected operation path determination unit 16 indicates that the operation is impossible, the corrected integrated value calculation unit 171a calculates the corrected command value from the command value candidate correction unit 14 using the following formula (6). A correction amount ΔJ(k), which is the difference between the candidate and the command value candidate from the command value candidate generation unit 12, is calculated.

Then, the corrected integrated value calculation unit 171a calculates the corrected integrated value ΔJ _sum within the arrival time of the correction amount ΔJ using the following formula (7).

Here, ΔJ _sum,0 is the initial value of the corrected integrated value, and the motion path passing through the command value candidate in the control cycle when it is determined that the motion path after correction is judged to be inoperable, and the previous output to the robot 10 It is the amount of correction between the motion path passing through the command value. The initial value ΔJ _sum,0 will be described in detail with reference to FIG. 11 . Also, _tT is the arrival time, and _Ts is the actual control cycle. Also, floor(y) is obtained by truncating the decimal point of y to an integer. The corrected integrated value calculation unit 171a calculates a corrected integrated value ΔJ _sum for joint angles corresponding to one or more joints using Equation (7). When the determination result from the corrected operation path determination unit 16 indicates that the vehicle is operable, the corrected integrated value calculation unit 171a clears the corrected integrated value. i.e. set to zero.

The restoration amount calculation unit 172a calculates the restoration amount when the determination result from the corrected movement path determination unit 16 indicates that the movement is impossible. Then, the restoration amount calculation unit 172a calculates the restoration time based on the corrected integrated value from the corrected integrated value calculation unit 171a. The amount of restoration and the restoration time will be described later in detail with reference to FIG. When the determination result from the post-correction motion path determination unit 16 indicates that the motion is operable, the restoration amount calculation unit 172a sets the restoration amount to zero.

The command value calculation unit 173a calculates the arrival time from the corrected integrated value calculation unit 171a and the restoration time from the restoration amount calculation unit 172a when the determination result from the corrected operation path determination unit 16 indicates that the operation is impossible. compare. The command value calculator 173a calculates a command value based on the comparison result between the arrival time and the restoration time. When the determination result from the corrected operation path determination unit 16 indicates that the vehicle is operable, the command value calculation unit 173a calculates the corrected command value candidate as the command value.

FIGS. 11(a) and 11(b) are schematic diagrams showing an example of the motion of the robot 10 according to the second embodiment. FIGS. 11A and 11B show the case where the target position is changed to GLb while the robot 10 is moving from the motion start position ST toward the target position GLa along the preset motion path Ra. 2 is a diagram showing the motion of the robot 10 in FIG.

As shown in FIG. 11(a), when the control cycle is 0, the operator or the robot control device 1a sets the hand of the robot 10 to the motion start position ST. In control cycle 1, the command value candidate generator 12 sets an interpolation point P1 on the motion path Ra. The command value output unit 17a outputs to the robot 10 a command value corresponding to the interpolation point P1.

Assume that the target position GLa is changed to GLb in control cycle 2. In this case, the command value candidate generation unit 12 sets an interpolation point P2 on the motion path Ra and uses this as a command value candidate. Further, the command value candidate correction unit 14 corrects the command value candidate P2 from the command value candidate generation unit 12 based on the external correction amount from the external correction amount acquisition unit 13, and the corrected command value candidate P21 is set. be. The external correction amount from the external correction amount acquisition unit 13 in control cycle 2 corresponds to the difference between the post-correction command value candidate P21 and the command value candidate P2. Next, the corrected motion path calculator 15 sets interpolation points P3, P4, . . . on the motion path Ra. Based on the interpolation points P3, P4, . . . Calculate a modified motion path R1 passing through . Next, the corrected motion path determination unit 16 determines whether the robot 10 can move the corrected command value candidates P21, positions P31, P41, . . . judge. As shown in FIG. 11(a), the surrounding environment SO exists on the post-correction motion path R1. In this case, the corrected motion path determining unit 16 determines that the robot 10 cannot move. Then, the arrival time from the time when it is determined to be inoperable to the time when it actually becomes inoperable is compared with the restoration time required to set the corrected integrated value of the command value candidate within the arrival time to zero. be. In FIG. 11A, if the restoration time is shorter than the arrival time, the command value output unit 17a outputs to the robot 10 a command value corresponding to the post-correction command value candidate P21.

In the case of FIG. 11A, the arrival time is the time from the time corresponding to control cycle 2 until the robot 10 reaches the position P4m. Specifically, the arrival time is the time from the position P1 of the robot 10 in the control cycle 2 to the position P4m through the positions P21, P31, P41, . . . . Here, the position P4m is a position on the corrected motion path R1, and is a position where interference with the surrounding environment SO begins. In addition, since the corrected motion path R1 is determined to be inoperable for the first time, the motion path Ra passing through the command value candidate P2 in the control period 2 at this time and the motion path passing through the previous command value P1 output to the robot 10 last time The difference with Ra is zero. Therefore, the initial value ΔJ _sum,0 of the corrected integrated value in control cycle 2 is zero. Assuming that the position on the motion path R2 passing through the target position GLb after change is reached within the arrival time, the corrected integrated value ΔJ _sum is, for example, the difference between the joint angle at position P21 and the joint angle at position P2, and the position It is obtained by adding the difference between the joint angle at P32 and the joint angle at position P31. The restoration time is the time required for the robot 10 to return from the motion route R2 passing through the position P32 to the motion route Ra. This restoration time will be described in detail with reference to FIG. 11(b).

In control cycle 3, the command value candidate generation unit 12 generates a command value candidate P31 based on the difference between the interpolation point P3 and the interpolation point P2 and the previous command value P21. Further, the command value candidate correction unit 14 corrects the command value candidate P31 from the command value candidate generation unit 12 based on the external correction amount from the external correction amount acquisition unit 13, and sets the command value candidate after correction P32. . The external correction amount in control cycle 3 corresponds to the difference between the post-correction command value candidate P32 and the command value candidate P31. Next, the post-correction motion path calculator 15 sets positions P42, . . . based on the positions P41, . A corrected motion path R2 passing through is calculated. Next, the corrected motion path determination unit 16 determines whether the robot 10 can move the corrected command value candidate P32, the position P42, . . . do. As shown in FIG. 11(a), the surrounding environment SO does not exist on the post-correction motion path R2. It is also assumed that the angular velocity and angular acceleration of the joints required for moving along the corrected motion path R2 are equal to or less than the upper limit values of the angular velocity and angular acceleration of the joints that the robot 10 can output. In this case, the corrected motion path determination unit 16 determines that the robot 10 is operable. The command value output unit 17a outputs to the robot 10 a command value corresponding to the post-correction command value candidate P32.

In the case of FIG. 11(a), the robot 10 is controlled to pass through the motion start position ST, position P1, position P21, position P32, position P42, . In this way, even if the determination result indicates that the robot 10 cannot move due to the presence of the surrounding environment SO on the corrected motion route R1 in control cycle 2, the robot 10 is given time to move along the corrected motion route R1. Therefore, the robot 10 can reach the target position GLb without passing through the target position GLa.

As shown in FIG. 11(b), when the control cycle is 0, the operator or the robot control device 1a sets the hand of the robot 10 to the motion start position ST. In control cycle 1, the command value candidate generator 12 sets an interpolation point P1 on the motion path Ra. The command value output unit 17a outputs to the robot 10 a command value corresponding to the interpolation point P1.

Assume that the target position GLa is changed to GLb in control cycle 2. In this case, the command value candidate generation unit 12 sets an interpolation point P2 on the motion path Ra and uses this as a command value candidate. Further, the command value candidate correction unit 14 corrects the command value candidate P2 from the command value candidate generation unit 12 based on the external correction amount from the external correction amount acquisition unit 13, and sets the corrected command value candidate P21. . The external correction amount from the external correction amount acquisition unit 13 in control cycle 2 corresponds to the difference between the post-correction command value candidate P21 and the command value candidate P2. Next, the corrected motion path calculator 15 sets interpolation points P3, P4, . . . on the motion path Ra. Based on the interpolation points P3, P4, . . . Calculate a modified motion path R1 passing through . Next, the corrected motion path determination unit 16 determines whether the robot 10 can move the corrected command value candidates P21, positions P31, . . . do. As shown in FIG. 11(b), the surrounding environment SO exists on the post-correction motion path R1. In this case, the corrected motion path determining unit 16 determines that the robot 10 cannot move. Then, the command value output unit 17a compares the arrival time and the restoration time. In FIG. 11B, assuming that the restoration time is shorter than the arrival time, the command value output unit 17a outputs to the robot 10 a command value corresponding to the post-correction command value candidate P21.

In the case of FIG. 11B, the arrival time is the time from the time corresponding to control cycle 2 until the robot 10 reaches the position P61. Specifically, the arrival time is the time from the position P1 of the robot 10 in the control cycle 2 to the position P61 through the positions P21, P31, and P41 on the corrected motion path R1. is the time equivalent to Here, the position P61 is a position on the corrected motion path R1 and is a position where interference with the surrounding environment SO begins. In addition, since the corrected motion path R1 is determined to be inoperable for the first time, the motion path Ra passing through the command value candidate P2 in the control period 2 at this time and the motion path passing through the previous command value P1 output to the robot 10 last time The difference with Ra is zero. Therefore, the initial value ΔJ _sum,0 of the corrected integrated value in control cycle 2 is zero. Assuming that the position on the motion path R2 passing through the target position GLb after change is reached within the arrival time, the corrected integrated value ΔJ _sum is, for example, the difference between the joint angle at position P21 and the joint angle at position P2, and the position It is obtained by adding the difference between the joint angle at P32 and the joint angle at position P31. The restoration time is the time required for the robot 10 to return from the corrected motion route R1 to the motion route Ra.

In control cycle 3, the command value candidate generation unit 12 generates a command value candidate P31 based on the difference between the interpolation point P3 and the interpolation point P2 and the previous command value P21. Further, the command value candidate correction unit 14 corrects the command value candidate P31 from the command value candidate generation unit 12 based on the external correction amount from the external correction amount acquisition unit 13, and sets the command value candidate after correction P32. . The external correction amount in control cycle 3 corresponds to the difference between the post-correction command value candidate P32 and the command value candidate P31. Next, the post-correction motion path calculator 15 sets positions P42, . . . based on the positions P41, . A corrected motion path R2 passing through is calculated. Next, the corrected motion path determination unit 16 determines whether the robot 10 can move the corrected command value candidates P32, positions P42, P52, . . . judge. As shown in FIG. 11(b), the surrounding environment SO exists on the post-correction motion path R2. In this case, the corrected motion path determining unit 16 determines that the robot 10 cannot move. Then, the command value output unit 17a compares the arrival time and the restoration time. In FIG. 11B, if the restoration time is shorter than the arrival time, the command value output unit 17a outputs to the robot 10 a command value corresponding to the post-correction command value candidate P32.

In the case of FIG. 11B, the arrival time is the time from the time corresponding to control cycle 3 until the robot 10 reaches the position P52. Specifically, the arrival time is the time from the position P21 of the robot 10 in the control cycle 3 to the position P52 through the positions P32 and P42 on the corrected motion route R2, which corresponds to 3 control cycles. It is time to Here, the position P52 is a position on the corrected motion path R2, and is a position where interference with the surrounding environment SO begins. Further, the initial value ΔJ _sum,0 of the corrected integrated value in the control cycle 3 is the difference between the motion path R1 passing through the previous command value P21 output to the robot 10 last time and the motion path Ra. It is the difference between the angle and the joint angle at position P2. The corrected integrated value ΔJ _sum is, for example, the sum of the difference between the joint angle at position P32 and the joint angle at position P31 and the initial value ΔJ _sum,0 . The restoration time is the time required for the robot 10 to return from the corrected motion route R2 to the motion route Ra.

In control cycle 4, the command value candidate generator 12 generates a command value candidate P42 based on the difference between the interpolation point P4 and the interpolation point P3 and the previous command value P32. Since the motion path R2 passing through the command value candidate P42 passes through the changed target position GLb, the external correction amount in the control cycle 4 becomes zero. Therefore, the command value candidate correcting unit 14 sets the post-correction command value candidate P42 that is the same as the command value candidate P42. Next, the corrected motion path determination unit 16 determines whether the robot 10 can move the corrected command value candidate P42, the position P52, . . . . As shown in FIG. 11(b), the surrounding environment SO exists on the post-correction motion path R2. In this case, the corrected motion path determining unit 16 determines that the robot 10 cannot move. Then, the command value output unit 17a compares the arrival time and the restoration time. In FIG. 11B, if the restoration time is equal to or longer than the arrival time, the command value output unit 17a outputs to the robot 10 a command value corresponding to the position PR41 in which the restoration amount is superimposed on the command value candidate P42.

In the case of FIG. 11B, the arrival time is the time from the time corresponding to control cycle 4 until the robot 10 reaches the position P52. Specifically, the arrival time is the time from the position P32 of the robot 10 in the control cycle 4 to the position P52 through the position P42 on the corrected motion path R2, and is the time corresponding to two control cycles. is. The initial value ΔJ _sum,0 of the corrected integrated value in control cycle 4 is the difference between the motion path R2 passing through the previous command value P32 output to the robot 10 last time and the motion path Ra. It is the difference between the angle and the joint angle at position P3. The corrected integrated value ΔJ _sum is the initial value ΔJ _sum,0 . Also, the restoration amount is the difference between the joint angle at the position P42 and the joint angle at the position PR41. The position PR41 is between the command value candidate P42 in the control period 4 and the position P4 on the movement path Ra at which the determination result indicates that the robot can move. It is a position set so as not to deviate from the motion restrictions. Also, the restoration time is calculated based on the restoration amount in the control period 4 and the restoration amounts in the subsequent control periods. In the case of FIG. 11B, the restoration amount in the next control cycle is the difference between the joint angle at position PR51 and the joint angle at position P5. That is, in the next control cycle, it is assumed that the determination result is likely to be restored to the position P5 on the operation path Ra where the operation becomes possible. In this case, the restoration time is a time corresponding to two control cycles. As described above, since the arrival time and the restoration time are the same, the command value to the robot 10 is the position PR41, assuming that there is a possibility of interference with the surrounding environment SO if the robot 10 continues to operate on the corrected motion trajectory R2.

In control cycle 5, the command value candidate generation unit 12 generates a command value candidate PR51 based on the difference between the interpolation point P5 and the interpolation point P4 and the previous command value PR41. Further, the command value candidate correction unit 14 corrects the command value candidate PR51 from the command value candidate generation unit 12 based on the external correction amount from the external correction amount acquisition unit 13, and sets the command value candidate after correction P52. . The external correction amount in control cycle 5 corresponds to the difference between the post-correction command value candidate P52 and the command value candidate PR51. Next, the corrected motion path calculator 15 sets positions PR61, PR71, . . . (not shown) based on the interpolation points P6, P7, . Based on the positions PR61, PR71, . Calculate a modified motion path R2 passing through . Next, the post-correction motion path determining unit 16 determines whether the robot 10 can or cannot move the post-correction command value candidates P52, . . . on the post-correction motion path R2. As shown in FIG. 11(b), the surrounding environment SO exists on the post-correction motion path R2. In this case, the corrected motion path determination unit 16 determines that the robot 10 cannot move. Then, the command value output unit 17a compares the arrival time and the restoration time. In FIG. 11B, if the restoration time is equal to or longer than the arrival time, the command value output unit 17a outputs to the robot 10 a command value corresponding to the position P5 where the restoration amount is superimposed on the command value candidate PR51.

In the case of FIG. 11B, the arrival time is the time from the time corresponding to control cycle 5 until the robot 10 reaches the position P52. Specifically, the arrival time is the time from the position PR41 of the robot 10 in the control cycle 5 to the position P52 on the corrected motion route R2, and is the time corresponding to one control cycle. The initial value ΔJ _sum,0 of the corrected integrated value in control cycle 5 is the difference between the motion path RR1 passing through the previous command value PR41 output to the robot 10 last time and the motion path Ra. It is the difference between the angle and the joint angle at position P4. The corrected integrated value ΔJ _sum is, for example, the sum of the difference between the joint angle at the position P52 and the joint angle at the position PR51 and the initial value ΔJ _sum,0 . The restoration amount is the difference between the joint angle at the position PR51 and the joint angle at the position P5. The restoration time is calculated based on the amount of restoration in control cycle 5 . In the case of FIG. 11B, in control cycle 5, the determination result can be restored to the position P5 on the operation path Ra where the operation is possible, so the restoration time is the time corresponding to one control cycle. As described above, since the arrival time and the restoration time are the same, the command value to the robot 10 is the position P5 assuming that there is a possibility of interfering with the surrounding environment SO when operating on the corrected motion trajectory R2.

In control cycle 6, the command value candidate generation unit 12 sets interpolation point P6 as a command value candidate. In addition, the command value candidate correction unit 14 sets a post-correction command value candidate P61. Since the corrected command value candidate P61 is a position that interferes with the surrounding environment SO, the command value output unit 17a outputs to the robot 10 a command value corresponding to the command value candidate P6.

From control cycle 7 onwards, the post-correction motion path is determined in the same way as before. Assuming that all the determination results of the corrected motion paths after the control period 7 are operable, control is performed from the position P6 to the position P71, the position P82, the position P92, and the target position GLb. As described above, in the case of FIG. 11(b), the robot 10 moves to the operation start position ST, position P1, position P21, position P32, position PR41, position P5, position P6, position P71, position P82, position P92, It is controlled to pass through the target position GLb.

FIG. 12 is a flow chart showing an example of the operation of the robot control device 1a according to the second embodiment. That is, FIG. 12 is a flow chart showing an example of the robot control method according to the second embodiment. 12 differs from FIG. 5 in that step ST9 is performed instead of step ST6. Since the steps other than step ST9 are the same as those shown in FIG. 5, description thereof is omitted.

The command value output unit 17a calculates a command value for the robot 10 using the command value candidate or the corrected command value candidate based on the determination result from the corrected motion path determination unit 16, and outputs the command value ( step ST9). The processing of step ST9 will be described in detail with reference to FIGS. 13 and 14. FIG.

FIG. 13 is a flow chart showing an example of the operation of the command value output unit 17a according to the second embodiment. That is, FIG. 13 is a flow chart showing details of the process of step ST9 in FIG.

As shown in FIG. 13 , when command value output processing is started by the command value output unit 17a, the command value output unit 17a receives the determination result from the post-correction operation path determination unit 16, and determines the input determination result. It is determined whether or not the result is operable (step ST91).

If the determination in step ST91 is "Yes", the process proceeds to step ST92. If the determination in step ST91 is "No", the process proceeds to step ST94.

If the determination in step ST91 is "Yes", the corrected integrated value calculator 171a clears the corrected integrated value (step ST92). That is, the corrected integrated value calculator 171a sets the corrected integrated value to zero.

The restoration amount calculator 172a sets the restoration amount to zero (step ST93).

If the determination in step ST91 is "No", the corrected integrated value calculation unit 171a calculates the arrival time from the time when the operation is determined to be inoperable to the time when it actually becomes inoperable (step ST94).

The corrected integrated value calculation unit 171a calculates the initial value of the corrected integrated value (step ST95).

The corrected integrated value calculation unit 171a calculates the corrected integrated value based on the formulas (6) and (7) (step ST96).

The restoration amount calculation unit 172a calculates the restoration amount in a certain control cycle k (step ST97).

The restoration amount calculation unit 172a calculates the restoration time required to zero the corrected integrated value calculated in step ST96 (step ST98).

The restoration amount calculation unit 172a determines whether or not the arrival time is equal to or less than the restoration time (step ST99).

If the determination in step ST99 is "Yes", the process proceeds to step ST100. If the determination in step ST99 is "No", the process proceeds to step ST93.

When the determination in step ST99 is "Yes", the command value calculation unit 173a calculates a command value for the robot 10 (step ST100). Specifically, the command value calculation unit 173a sets the command value by superimposing the restoration amount calculated in step ST97 on the command value candidate. After the processing of step ST100 is performed, the command value output unit 17a ends the command value output processing.

FIG. 14 is a flow chart showing another example of the operation of the command value output unit 17a according to the second embodiment. That is, FIG. 14 is a flow chart showing the details of the process of step ST9 in FIG. 14 differs from FIG. 13 in that step ST101 is performed instead of step ST98 and step ST102 is performed instead of step ST99. Since steps other than steps ST101 and ST102 are the same as those shown in FIG. 13, description thereof is omitted.

The restoration amount calculation unit 172a calculates the restoration integrated value of the restoration amount within the arrival time (step ST101).

The restoration amount calculation unit 172a determines whether or not the restoration integrated value is equal to or less than the corrected integrated value (step ST102).

If the determination in step ST102 is "Yes", the process proceeds to step ST100. If the determination in step ST102 is "No", the process proceeds to step ST93.

According to the second embodiment described above, even if it is determined that the motion path after correction is inoperable, the modified command value candidate is output to the robot 10 as the command value for a certain period of time. In some cases, the time required to move to the target position can be shortened.

Embodiment 3.
In Embodiment 3, it is determined whether the robot 10 is operable or inoperable with respect to the post-correction motion path based on the relative distance or relative speed from the surrounding environment SO with respect to each position of the post-correction motion path.

FIG. 15 is a block diagram showing an example of the robot control device 1b according to the third embodiment. 15 is that the robot control device 1b includes a command value candidate generation unit 12b instead of the command value candidate generation unit 12, and a corrected motion path determination unit 16b instead of the corrected motion path determination unit 16. , different from FIG. Since the parts other than the command value candidate generation unit 12b and the corrected motion path determination unit 16b are the same as those shown in FIG. 2, description thereof will be omitted.

The command value candidate generation unit 12b sets interpolation points passing through the motion path before change, and generates command value candidates based on the interpolation points. Further, the command value candidate generation unit 12b corrects the interpolation point based on the determination result from the post-correction motion path determination unit 16b, and generates the next command value candidate for the robot 10 based on the corrected interpolation point. . The command value candidate generator 12b will be described later in detail with reference to FIG.

The post-correction motion path determination unit 16b outputs determination results based on the relative distance or relative speed from the surrounding environment SO around the robot 10 with respect to each position of the post-correction motion path, in addition to the determination results described in the first embodiment. .

FIG. 16 is a block diagram showing an example of the command value candidate generating section 12b according to the third embodiment. The command value candidate generation unit 12b includes an interpolation point setting unit 121b, a previous interpolation point holding unit 122, a relative value calculation unit 123, and a command value candidate calculation unit . FIG. 16 is different from FIG. 3 in that the command value candidate generation unit 12b includes an interpolation point setting unit 121b instead of the interpolation point setting unit 121. FIG. Since the components other than the interpolation point setting unit 121b are the same as those shown in FIG. 3, description thereof will be omitted.

The interpolation point setting unit 121b corrects the interpolation points based on the determination result from the post-correction motion path determination unit 16b. Assuming that the robot 10 moves on the corrected movement path, the robot 10 needs to decelerate when the surrounding environment SO approaches the corrected movement path from the front. Therefore, the interpolation point setting unit 121b reduces the interval between interpolation points. Further, when the surrounding environment SO approaches the corrected motion path from behind, the robot 10 needs to be accelerated. Therefore, the interpolation point setting unit 121b increases the interval between the interpolation points. When increasing the intervals between the interpolation points, the interpolation point setting unit 121b sets the interpolation points so that the upper limit values of the joint angular velocity and angular acceleration that the robot 10 can output are not exceeded.

The interpolation point setting unit 121b does not necessarily need to set interpolation points to decelerate the robot 10, for example, when the surrounding environment SO faces the corrected motion path from the front. The interpolation point setting unit 121b may decelerate the robot 10 if the relative distance from each position on the corrected motion path to the surrounding environment SO is equal to or less than a predetermined value, or if the relative speed is equal to or greater than a predetermined value. The predetermined value is, for example, a value that eliminates the possibility of collision with the surrounding environment SO when the robot 10 moves on the corrected motion path.

17(a) and 17(b) are schematic diagrams showing an example of the motion of the robot 10 according to the third embodiment. FIGS. 17A and 17B show the case where the target position is changed to GLb while the robot 10 is moving from the motion start position ST toward the target position GLa along the preset motion path Ra. 2 is a diagram showing the motion of the robot 10 in FIG. FIG. 17(a) is a diagram showing the motion of the robot 10 when the surrounding environment SO is approaching from the front. FIG. 17(b) is a diagram showing the motion of the robot 10 when the surrounding environment SO is approaching from behind.

As shown in FIG. 17(a), when the control period is 0, the operator or the robot control device 1b sets the hand of the robot 10 to the motion start position ST. In control cycle 1, the command value candidate generator 12b sets an interpolation point P2 on the motion path Ra. The command value output unit 17 outputs to the robot 10 a command value corresponding to the interpolation point P1.

Assume that the target position GLa is changed to GLb in control cycle 2. In this case, the command value candidate generation unit 12b sets an interpolation point P2 on the motion path Ra and uses this as a command value candidate. Further, the command value candidate correction unit 14 corrects the command value candidate P2 from the command value candidate generation unit 12b based on the external correction amount from the external correction amount acquisition unit 13, and sets the corrected command value candidate P21. . The external correction amount from the external correction amount acquisition unit 13 in control cycle 2 corresponds to the difference between the post-correction command value candidate P21 and the command value candidate P2. Next, the corrected motion path calculator 15 sets interpolation points P3, P4, . . . on the motion path Ra. Note that the interpolation points P3, P4, . . . set here are different from the interpolation points P3, P4, . Based on the interpolation points P3, P4, . . . Calculate a modified motion path R1 passing through . Positions P31, P41, . . . set here are different from positions P31, P41, . Next, the corrected motion path determination unit 16b determines whether the robot 10 can move the corrected command value candidates P21, positions P31, P41, . . . judge. As shown in FIG. 17A, the corrected motion path determination unit 16b determines that the surrounding environment SO does not exist on the corrected motion path R1, but is approaching from the front. In this case, the corrected motion path determination unit 16b determines that the robot 10 cannot move. The command value output unit 17 outputs to the robot 10 a command value corresponding to the command value candidate P2. Since the surrounding environment SO does not exist on the corrected motion path R1, the command value output unit 17 may output to the robot 10 a command value corresponding to the corrected command value candidate P21. Here, the command value output unit 17 sets the command value candidate P2 as the command value for the robot 10 .

Note that the post-correction motion path determination unit 16b determines that when the relative distance between each position on the post-correction motion path R1 and the surrounding environment SO suddenly decreases, or when the relative speed suddenly increases, the surrounding environment SO Judging that it is coming from the front. When the corrected motion path determination unit 16b determines that the relative distance is equal to or less than a predetermined value or that the relative speed is equal to or greater than a predetermined value, the corrected motion path determining unit 16b determines that the motion is impossible as a result of the determination. The post-correction motion path determination unit 16b may only determine whether the relative distance is equal to or less than a predetermined value, or may determine whether the relative speed is equal to or greater than a predetermined value. Alternatively, the post-correction motion path determination unit 16b may use relative acceleration. That is, when the corrected motion path determination unit 16b determines that the relative acceleration is equal to or greater than a predetermined value, the determination result may be the inability to move.

In the control cycle 3, the command value candidate generation unit 12b sets a point P3 with a small interval from the interpolation point P2 on the operation path Ra as shown in FIG. . That is, the robot 10 is controlled to slow down. This is because it was determined in the previous control cycle that the surrounding environment SO was approaching from the front. In control cycle 3, the command value candidate generator 12b sets the interpolation point P3 as a command value candidate. Further, the command value candidate correction unit 14 corrects the command value candidate P3 from the command value candidate generation unit 12b based on the external correction amount from the external correction amount acquisition unit 13, and sets the corrected command value candidate P31. . The external correction amount in control cycle 3 corresponds to the difference between the post-correction command value candidate P31 and the command value candidate P3. Next, as shown in FIG. 17A, the post-correction motion path calculation unit 15 sets interpolation points P4, . Based on the interpolation points P4, . A post-movement path R1 is calculated. Next, the corrected motion path determination unit 16b determines whether the robot 10 can move the corrected command value candidates P31, positions P41, . . . do. Since the operation after this is the same as the operation in the control period 2, the explanation is omitted.

As shown in FIG. 17(b), when the control period is 0, the operator or the robot control device 1b sets the hand of the robot 10 to the motion start position ST. In control cycle 1, the command value candidate generator 12b sets an interpolation point P2 on the motion path Ra. The command value output unit 17 outputs to the robot 10 a command value corresponding to the interpolation point P1.

Assume that the target position GLa is changed to GLb in control cycle 2. In this case, the command value candidate generation unit 12b sets an interpolation point P2 on the motion path Ra and uses this as a command value candidate. Further, the command value candidate correction unit 14 corrects the command value candidate P2 from the command value candidate generation unit 12b based on the external correction amount from the external correction amount acquisition unit 13, and sets the corrected command value candidate P21. . The external correction amount from the external correction amount acquisition unit 13 in control cycle 2 corresponds to the difference between the post-correction command value candidate P21 and the command value candidate P2. Next, the corrected motion path calculator 15 sets interpolation points P3, P4, . . . on the motion path Ra. Note that the interpolation points P3, P4, . . . set here are different from the interpolation points P3, P4, . Based on the interpolation points P3, P4, . . . Calculate a modified motion path R1 passing through . Positions P31, P41, . . . set here are different from positions P31, P41, . Next, the corrected motion path determination unit 16b determines whether the robot 10 can move the corrected command value candidates P21, positions P31, P41, . . . judge. As shown in FIG. 17B, the corrected motion path determination unit 16b determines that the surrounding environment SO does not exist on the corrected motion path R1, but is approaching from behind. In this case, the corrected motion path determination unit 16b determines that the robot 10 cannot move. The command value output unit 17 outputs to the robot 10 a command value corresponding to the command value candidate P2. Since the surrounding environment SO does not exist on the corrected motion path R1, the command value output unit 17 may output to the robot 10 a command value corresponding to the corrected command value candidate P21. Here, the command value output unit 17 sets the command value candidate P2 as the command value for the robot 10 .

Note that the post-correction motion path determining unit 16b determines that the position of the surrounding environment SO is determined when the relative distance to each position on the post-correction motion path R1 from the surrounding environment SO gradually decreases, or when the relative speed gradually increases. Determined to come from behind. When the corrected motion path determination unit 16b determines that the relative distance is equal to or less than a predetermined value or that the relative speed is equal to or greater than a predetermined value, the corrected motion path determining unit 16b determines that the motion is impossible as a result of the determination. The post-correction motion path determination unit 16b may only determine whether the relative distance is equal to or less than a predetermined value, or may determine whether the relative speed is equal to or greater than a predetermined value. Alternatively, the post-correction motion path determination unit 16b may use relative acceleration. That is, when the corrected motion path determination unit 16b determines that the relative acceleration is equal to or greater than a predetermined value, the determination result may be the inability to move.

In the control cycle 3, the command value candidate generation unit 12b sets a point P3 on the operation path Ra with an increased interval from the interpolation point P2 as shown in FIG. . That is, the robot 10 is controlled to increase its speed. This is because it was determined in the previous control cycle that the surrounding environment SO was approaching from behind. In control cycle 3, the command value candidate generator 12b sets the interpolation point P3 as a command value candidate. Further, the command value candidate correction unit 14 corrects the command value candidate P3 from the command value candidate generation unit 12b based on the external correction amount from the external correction amount acquisition unit 13, and sets the corrected command value candidate P31. . The external correction amount in control cycle 3 corresponds to the difference between the post-correction command value candidate P31 and the command value candidate P3. Next, as shown in FIG. 17B, the post-correction motion path calculator 15 sets interpolation points P4, . Based on the interpolation points P4, . A post-movement path R1 is calculated. Next, the corrected motion path determination unit 16b determines whether the robot 10 can move the corrected command value candidates P31, positions P41, . . . do. Since the operation after this is the same as the operation in the control period 2, the explanation is omitted.

FIG. 18 is a flow chart showing an example of the operation of the robot control device 1b according to the third embodiment. That is, FIG. 18 is a flow chart showing an example of the robot control method according to the third embodiment. 18 differs from FIG. 5 in that step ST11 is performed instead of step ST5 and step ST12 is performed instead of step ST2. Since steps other than steps ST11 and ST12 are the same as those shown in FIG. 5, description thereof is omitted.

The post-correction motion path determination unit 16b determines whether the robot 10 is operable or inoperable with respect to the post-correction motion path, and outputs the determination result. Further, the post-correction motion path determination unit 16b outputs a determination result based on the relative distance or relative speed between each position of the post-correction motion path and the surrounding environment SO around the robot (step ST11). The processing of step ST11 will be described in detail using FIG.

The command value candidate generation unit 12b corrects the interpolation point based on the determination result from the corrected motion path determination unit 16b, and generates the next command value candidate based on the corrected interpolation point (step ST12). The processing of step ST12 will be described in detail using FIG.

FIG. 19 is a flow chart showing an example of the operation of the post-correction motion path determination unit 16b according to the third embodiment. That is, FIG. 19 is a flow chart showing details of the process of step ST11 in FIG. FIG. 19 differs from FIG. 8 in that the processing from step ST111 to step ST113 is performed. Since steps other than steps ST111 to ST113 are the same as those shown in FIG. 8, description thereof is omitted.

After the process of step ST51 is performed, the post-correction motion path determination unit 16b sets the flag to 0 (step ST111). The flag is a variable that indicates whether or not the command value candidate generation unit 12b corrects the interpolation point. After the process of step ST111 is performed, the process of step ST52 is performed.

After the process of step ST53 is performed, the post-correction motion path determination unit 16b determines whether the relative distance is equal to or less than a predetermined value or the relative speed is equal to or greater than a predetermined value (step ST112). Note that the post-correction motion path determination unit 16b may simply determine whether the relative distance is equal to or less than a predetermined value, or may determine whether the relative speed is equal to or greater than a predetermined value.

If the determination in step ST112 is "Yes", the process proceeds to step ST54. If the determination in step ST112 is "No", the process proceeds to step ST113.

When the determination in step ST112 is "No", the post-correction motion path determination unit 16b sets the flag to 1 (step ST113). After the process of step ST113 is performed, the process of step ST55 is performed. Note that the process of step ST54 may be performed after the process of step ST113 is performed. That is, even if the determination in step ST112 is "No", the post-correction movement path determination unit 16b does not perform the process of making the determination result inoperable in step ST55, and continues the processes from step ST54 to step ST58. you can go Even if the determination in step ST112 is "No", the post-correction motion path determination unit 16b may determine that the determination result is "Yes" in steps ST56 to ST58.

FIG. 20 is a flow chart showing an example of the operation of the command value candidate generator 12b according to the third embodiment. That is, FIG. 20 is a flow chart showing details of the process of step ST12 in FIG. FIG. 20 differs from FIG. 6 in that steps ST121 and ST122 are performed. Since steps other than steps ST121 and ST122 are the same as those shown in FIG. 6, description thereof is omitted.

When command value candidate generation processing is started by the command value candidate generation unit 12b, the interpolation point setting unit 121b determines whether or not the flag is 1 (step ST121).

If the determination in step ST121 is "Yes", the process proceeds to step ST122. If the determination in step ST121 is "No", the process proceeds to step ST22.

If the determination in step ST121 is "Yes", the interpolation point setting unit 121b corrects the interpolation point J(k) in a certain control cycle k (step ST122). For example, when the surrounding environment SO approaches the corrected motion path from the front, the interpolation point setting unit 121b corrects the interpolation points J(k) so that the intervals between the interpolation points are reduced. Further, when the surrounding environment SO approaches the corrected motion path from behind, the interpolation point setting unit 121b corrects the interpolation points J(k) so that the intervals between the interpolation points are increased. After the process of step ST122 is performed, the process of step ST22 is performed.

According to the third embodiment described above, the command value candidate generation unit 12b corrects the interpolation point on the motion path based on the relative distance or relative speed from the surrounding environment SO with respect to each position on the motion path after correction. Therefore, the robot 10 can be appropriately controlled not only when the surrounding environment SO is stationary but also when it is moving.

Although the case where the third embodiment is applied to the first embodiment has been described here, the third embodiment can also be applied to the second embodiment.

1, 1a, 1b Robot controller, 11 Operation program storage unit, 12, 12b Command value candidate generation unit, 121, 121b Interpolation point setting unit, 122 Previous interpolation point holding unit, 123 Relative value calculation unit, 124 Command value candidate calculation 13 external correction amount acquisition unit 14 command value candidate correction unit 15 post-correction motion

path calculation unit

16, 16b post-correction motion

path determination unit

17, 17a command value output unit 171a corrected integrated value calculation unit 172a Restoration amount calculation unit, 173a command value calculation unit, 2 CPU, 3 storage device, 4 IO interface, 6 receiving device, 7 input device, 10 robot, SO peripheral environment.

Claims

A command value for generating a command value candidate for the robot based on an operation program composed of a motion path of the robot generated in advance and a previous command value output to the robot last time or motion information of the robot. a candidate generator;
a command value candidate correction unit that corrects the command value candidate to obtain a post-correction command value candidate based on the external correction amount associated with the change of the motion path;
a corrected motion path determination unit that determines whether the robot is operable or inoperable with respect to the corrected motion path that passes through the corrected command value candidates, and outputs a determination result;
a command value output unit that calculates a command value for the robot using the command value candidate or the corrected command value candidate based on the determination result and outputs the command value;
A robot controller comprising:
The robot control device according to claim 1, wherein the corrected motion path is a difference between the corrected command value candidate and the command value candidate with respect to the motion path passing through the command value candidate.
If the robot can follow the corrected motion path, the corrected motion path determining unit determines that the determination result is operable, and if the robot cannot follow the corrected motion path, the determination result. 3. The robot control device according to claim 1 or 2, wherein the operation is disabled.
The command value output unit sets the corrected command value candidate as the command value when the determination result indicates that the operation is possible, and changes the command value candidate to the command value when the determination result indicates that the operation is impossible. The robot control device according to any one of claims 1 to 3, wherein:
The command value output unit sets the corrected command value candidate as the command value when the determination result indicates that the operation is possible, and determines that the operation is not possible when the determination result indicates that the operation is impossible. The arrival time from the time to the time when the operation becomes impossible is compared with the restoration time required to set the corrected integrated value of the command value candidate within the arrival time to zero, and the restoration time is greater than the arrival time. is smaller, the corrected command value candidate is used as the command value, and when the restoration time is equal to or longer than the arrival time, the restoration amount calculated when it is determined that the operation is impossible is superimposed on the command value candidate. 4. The robot control device according to any one of claims 1 to 3, wherein the command value is a value of .
The command value output unit sets the corrected command value candidate as the command value when the determination result indicates that the operation is possible, and determines that the operation is not possible when the determination result indicates that the operation is impossible. Comparing the corrected integrated value of the command value candidate within the arrival time from the time to the time when the operation becomes impossible with the restoration integrated value within the arrival time of the restoration amount calculated when it is determined that the operation is impossible. when the modified integrated value is smaller than the restored integrated value, the command value candidate after modification is set as the command value, and when the modified integrated value is equal to or greater than the restored integrated value, the restored amount is set as the command value candidate 4. The robot control device according to any one of claims 1 to 3, wherein the command value is superimposed on the .
The robot control device according to claim 5 or 6, wherein the command value output unit calculates the restoration amount so as not to deviate from the movement restrictions of the robot.
The robot control device according to any one of claims 1 to 7, wherein the command value candidate generation unit sets interpolation points passing through the motion path and generates the command value candidates based on the interpolation points.
The corrected motion path determining unit outputs the determination result based on the relative position or relative speed of the surrounding environment around the robot with respect to each position of the corrected motion path,
9. The robot controller according to claim 8, wherein the command value candidate generating section corrects the interpolation point based on the determination result, and generates the next command value candidate based on the corrected interpolation point.
a step of generating a command value candidate for the robot based on a motion program composed of a motion path of the robot generated in advance and a previous command value output to the robot last time or motion information of the robot; ,
a step of correcting the command value candidate as a post-correction command value candidate based on the external correction amount associated with the change of the motion path;
a step of determining whether the modified motion path passing through the modified command value candidate is operable or inoperable, and outputting the determination result;
a step of calculating a command value for the robot using the command value candidate or the corrected command value candidate based on the determination result, and outputting the command value;
A robot control method comprising: