JP2020185637A - Robot program evaluation device, robot program evaluation method and robot program evaluation program - Google Patents

Abstract

To evaluate pass-operation between work points in which interference regions exist in terms of time.SOLUTION: A robot program evaluation device comprises a pass-operation evaluation part 63 that calculates a reference maximum operation time, being a maximum operation time of operation times corresponding to variation absolute values of shafts with respect to a shortest pass operation that directly operates on an attitude of a current work point which is a work position for a tip of a robot arm and then on an attitude of the next work point, forms pass-operation to be evaluated which passes through one or more relay work points where the attitudes are set, in a range from the current work point to the next work point, determines the maximum operation time of the operation times corresponding to the variation-absolute values of the shafts for each of a plurality of divided pass operations into which the pass operation to be evaluated is divided by the relay work points, calculates the total of the maximum operation times of the divided operation passes as a comparison-maximum operation time, and outputs the magnitude in a magnitude relation between the reference maximum operation time and the comparison maximum operation time as an evaluated value of the pass operation to be evaluated.SELECTED DRAWING: Figure 2

Description

The present invention relates to a robot program evaluation device, a robot program evaluation method, and a robot program evaluation program that can evaluate a path motion between work points in the presence of an interference region in terms of time.

In order for a robot to perform work such as welding, a robot operation program is required. This robot operation program is created by performing an actual machine teaching operation in which a robot teaches a work position and a posture such as a welding position to a work arranged on a robot line. However, in this actual machine teaching work, there is a problem that the production line is stopped and teaching skills are required. Furthermore, in the actual teaching work, it is necessary to ensure safety because the robot approaches the robot. Therefore, when creating a robot operation program, an offline teaching system using a computer is often used.

In Patent Document 1, an evaluation function for evaluating the change in the angular velocity of the predetermined axis of the robot in the designated section is set based on the teaching data of the designated section of the movement path, and the change in the angular velocity of the predetermined axis of the robot is minimized. It is disclosed that the teaching data of the attitude angle in the designated section is corrected so that the value of the evaluation function becomes.

Japanese Unexamined Patent Publication No. 7-334228

By the way, when spot welding of a plurality of points using a welding gun or the like is performed, a pass operation is performed in which the tip position of the robot arm is moved from the current work point to the next work point. Then, in this pass operation, it is necessary to move the posture of the robot arm at the current work point to the posture of the robot arm at the next work point.

When performing this path operation, if there is an interference region that interferes with the work between the current work point and the next work point, it is necessary to perform a detour operation that avoids this interference area. If there is no interference area, the tip position of the robot arm can be moved directly from the current work point to the next work point, and the posture of the robot arm at the current work point and the robot arm at the next work point Since the posture has already been determined, the drive of each axis of the robot arm is uniquely determined.

On the other hand, when an interference area exists, one or more relay work points that define the movement path of the tip position of the robot arm are set between the current work point and the next work point, and the robot arm sets the interference area. Make the path action to avoid. In addition, the posture of the robot arm is set at each relay work point. The relay work point and the posture of the robot arm at the relay work point can be freely set. In particular, the posture of the multi-axis robot arm has a high degree of freedom. Therefore, there is a problem that it is difficult to determine what kind of path operation is optimal. In particular, the operating angular velocities of each axis of the robot arm are different, and the time required to complete the posture change of the robot arm is affected by one axis having a slow operation completion time.

The present invention has been made to solve the above problems, and is a robot program evaluation device, a robot program evaluation method, and a robot that can evaluate a path motion between work points in the presence of an interference region in terms of time. The purpose is to provide a program evaluation program.

In order to solve the above-mentioned problems and achieve the object, the present invention includes a change in the posture of the robot between work points when creating an operation program of a robot that drives a plurality of axes of a robot arm to perform work. A robot program evaluation device that evaluates path motion, and is an absolute value of change in each axis with respect to the shortest path motion that directly operates from the posture of the current work point, which is the tip work position of the robot arm, to the posture of the next work point. The reference maximum operation time, which is the maximum operation time of each operation time corresponding to, is calculated, and one or more relay work points whose postures are set between the current work point and the next work point. The evaluation target path operation is formed via the above, and the evaluation target path operation is divided by the relay work point. The maximum of each operation time corresponding to the absolute value of the change amount of each axis for each of the plurality of division path operations. The operation time is obtained, the sum of the maximum operation times of each divided path is calculated as the comparison maximum operation time, and the magnitude of the magnitude relationship between the reference maximum operation time and the comparison maximum operation time is evaluated for the evaluation target path operation. It is characterized by being output as a value.

Further, the present invention is characterized in that, in the above invention, the evaluation value indicates the ratio of the reference maximum operating time to the comparative maximum operating time as a percentage.

Further, in the above invention, the present invention displays the evaluation value, the operating time of each axis of the shortest path operation, and the operating time of each axis of the divided path operation, and emphasizes at least the maximum operating time of each axis. It is characterized by displaying.

Further, the present invention is a robot program evaluation method for evaluating a path motion including a change in the posture of the robot between work points when creating a motion program of a robot that drives a plurality of axes of a robot arm to perform work. Therefore, the maximum operation of each operation time corresponding to the absolute value of the amount of change of each axis with respect to the shortest path operation that directly operates from the posture of the current work point, which is the tip work position of the robot arm, to the posture of the next work point. The evaluation target path operation via one or more relay work points whose postures are set between the reference calculation step for calculating the reference maximum operation time, which is the time, and the current work point to the next work point. Is formed, the maximum operation time of each operation time corresponding to the absolute value of the change amount of each axis is obtained for each of the plurality of division path operations in which the evaluation target path operation is divided by the relay work point, and each division path is obtained. Outputs the magnitude of the magnitude relationship between the reference maximum operation time and the comparison maximum operation time as the evaluation value of the evaluation target path operation and the comparison target calculation step that calculates the sum of the maximum operation times of the above as the comparison maximum operation time. It is characterized by including an evaluation step to be performed.

Further, the present invention is a robot program evaluation program that evaluates a path motion including a change in the posture of the robot between work points when creating a motion program of a robot that drives a plurality of axes of a robot arm to perform work. Therefore, the maximum operation of each operation time corresponding to the absolute value of the amount of change of each axis with respect to the shortest path operation that directly operates from the posture of the current work point, which is the tip work position of the robot arm, to the posture of the next work point. The reference calculation procedure for calculating the reference maximum operation time, which is the time, and the evaluation target path operation via one or more relay work points in which the posture is set between the current work point and the next work point. Is formed, the maximum operation time of each operation time corresponding to the absolute value of the change amount of each axis is obtained for each of the plurality of division path operations in which the evaluation target path operation is divided by the relay work point, and each division path is obtained. The comparison target calculation procedure that calculates the sum of the maximum operating times of the above as the comparison maximum operating time and the magnitude of the magnitude relationship between the reference maximum operating time and the comparative maximum operating time are output as the evaluation value of the evaluated path operation. It is characterized by having a computer execute an evaluation procedure to be performed.

According to the present invention, the path operation between working points in the presence of an interference region can be evaluated in terms of time.

FIG. 1 is a diagram showing an outline configuration of a robot system controlled by an operation program created by the robot program evaluation device according to the present embodiment. FIG. 2 is a functional block diagram showing the configuration of the robot program evaluation device. FIG. 3 is a flowchart showing a path motion evaluation processing procedure by the path motion evaluation unit. FIG. 4 is a diagram showing a maximum axial speed and a maximum unit operating time of each axis of the robot arm. FIG. 5 is a diagram showing the posture of the work point in the shortest path operation, the absolute value of the change amount of each axis, and the operation time. FIG. 6 is a diagram showing the postures of the work point and the relay work point in the path operation to be evaluated, the absolute value of the amount of change of each axis, and the operation time. FIG. 7 is a diagram showing an operation time and an evaluation value of each axis of the pass operation.

Hereinafter, the robot program evaluation device, the robot program evaluation method, and the robot program evaluation program according to the present embodiment will be described with reference to the attached drawings.

<Robot configuration>
FIG. 1 is a diagram showing an outline configuration of a robot system 1 controlled by an operation program 4 created by the robot program evaluation device according to the present embodiment. In this embodiment, a robot system 1 that performs welding work as a robot system will be described as an example. The robot system 1 performs spot welding on work points P1 and P2, which are work points of the vehicle body 100 to be worked.

As shown in FIG. 1, the robot system 1 includes a robot 2 and a control device 3. The robot 2 has, for example, a 6-axis robot arm 5. A welding gun 6 is provided at the tip position of the robot arm 5. The control device 3 controls the welding work of the robot 2 on the vehicle body 100 by the operation program 4.

The robot 2 changes the posture of the robot arm 5 so that the tip position of the robot arm 5 enters the work point P1 from the standby position, holds the posture at the work point P1 and sandwiches the work point P1, and is electrically operated by the welding gun 6. Welding work is performed by welding or the like. After that, the robot 2 moves to the next work point P2, holds the posture at the work point P2, sandwiches the work point P2, and performs the welding work by the welding gun 6. After that, the robot arm 5 is moved to the standby position, and when the next vehicle body 100 is conveyed, the above operation is repeated as a cycle.

Here, when the interference region 101 exists between the work points P1 and P2, the robot 2 controls the tip position of the robot arm 5 to pass through the relay work point P10 in order to avoid interference with the interference region 101. To do. At the relay work point P10, the posture is also controlled so that the tip position of the robot arm 5 becomes the relay work point P10.

When the interference region 101 does not exist, the robot 2 performs a pass operation L0 in which the tip position of the robot arm 5 moves from the work point P1 to the work point P2 at the shortest distance. In this pass operation, each axis of the robot arm 5 is controlled so as to change from the posture of the work point P1 to the posture of the work point P2.

When the interference region 101 exists, the robot 2 has a path operation of the split path L1 in which the tip position of the robot arm 5 moves from the work point P1 to the relay work point P10, and the tip position of the robot arm 5 is from the relay work point P10. The path operation of the divided path L2 that moves to the work point P2 is performed. In the pass operation of the divided path L1, each axis of the robot arm 5 is controlled so as to change from the posture of the work point P1 to the posture of the relay work point P10. Further, in the pass operation of the divided path L2, each axis of the robot arm 5 is controlled so as to change from the posture of the relay work point P10 to the posture of the work point P2. One or more relay work points P10 are provided according to the shape of the interference region 101 and the like.

<Structure of robot program evaluation device>
FIG. 2 is a functional block diagram showing the configuration of the robot program evaluation device 10. In this embodiment, a robot offline program system that creates an operation program 4 offline is applied. The robot program evaluation device 10 has a function of evaluating the path operation of the operation program 4, but also has a function of creating the operation program 4 offline.

As shown in FIG. 2, the robot program evaluation device 10 includes an input unit 20, a display unit 30, a communication unit 40, a storage unit 50, and a control unit 60.

The input unit 20 is an input device such as a keyboard or a mouse, the display unit 30 is a display device such as a liquid crystal panel, and the communication unit 40 is a communication interface for communicating with another device including the control device 3. It is a department.

The storage unit 50 is a storage device including a hard disk device, a non-volatile memory, or the like, and stores CAD data 51, robot software 52, and an operation program 4. The CAD data 51 is three-dimensional data of the vehicle body 101 including the work points P1 and P2. The robot software 52 is the same software as software such as an operating system that is incorporated in the control device 3 and executes and controls the operation program 4.

The control unit 60 is a control unit that controls the entire robot program evaluation device 10, and includes a program creation unit 61, a simulation unit 62, and a path motion evaluation unit 63. The control unit 60 stores the programs corresponding to the program creation unit 61, the simulation unit 62, and the path operation evaluation unit 63 in a storage device such as a non-volatile memory or a magnetic disk device, and loads these programs into the memory. Then, by executing it on the CPU, the corresponding process is executed.

The program creation unit 61 is a program that creates the operation program 4 offline. The program creation unit 61 creates the operation program 4 by displaying the CAD data 51 in three dimensions and generating teacher data for the vehicle body 100 displayed in three dimensions.

The simulation unit 62 operates the created operation program 4 on the robot software 52 to perform debugging processing and correction of control errors and the like.

The path motion evaluation unit 63 evaluates the path motion including the posture change of the robot 2 between the work points when creating the motion program 4 of the robot that drives the plurality of axes of the robot arm 5 to perform the work.

The path motion evaluation unit 63 operates each motion time corresponding to the absolute value of the amount of change of each axis with respect to the shortest path motion that directly operates from the posture of the current work point, which is the tip work position of the robot arm 5, to the posture of the next work point. The reference maximum operating time, which is the maximum operating time, is calculated, and the path operation to be evaluated via one or more relay work points with a set posture between the current work point and the next work point. The maximum operation time of each operation time corresponding to the absolute value of the change amount of each axis is obtained for each of the plurality of division path operations in which the evaluation target path operation is divided by the relay work point. The sum of the maximum operating times is calculated as the comparative maximum operating time, and the magnitude of the magnitude relationship between the reference maximum operating time and the comparative maximum operating time is output as the evaluation value of the evaluated path operation.

The evaluation value is, for example, the ratio of the reference maximum operating time to the comparative maximum operating time as a percentage. This evaluation value indicates that the larger the value, the shorter the operation time of the pass operation, and therefore the more appropriate the time of the pass operation. The ratio of the comparative maximum operating time to the reference maximum operating time may be indicated as a percentage.

Further, the evaluation value, the operation time of each axis of the shortest path operation, and the operation time of each axis of the divided path operation are displayed on the display unit 30, and at that time, at least the maximum operation time of each axis is highlighted. As a result, the axis affecting the operation time of the path operation can be identified, and the path operation can be easily analyzed.

<Path operation evaluation process>
Next, the path operation evaluation process by the path operation evaluation unit 63 will be described. FIG. 3 is a flowchart showing a path operation evaluation processing procedure by the path operation evaluation unit 63. As shown in FIG. 3, first, the path operation evaluation unit 63 calculates the absolute value of the amount of change of each axis during the shortest path operation (step S101). After that, the operation time corresponding to the calculated absolute value of the change amount of each axis is calculated (step S102). Further, the maximum operating time of the calculated operating times is extracted as the reference maximum operating time (step S103).

After that, the absolute value of the amount of change of each axis for each divided path operation during the evaluated path operation, which is the path operation of the detour route, is calculated (step S104). After that, the operation time corresponding to the absolute value of the change amount of each axis is calculated for each division path operation (step S105). Further, the maximum operating time of the operating time is extracted for each divided path operation (step S106). After that, the comparative maximum operating time, which is the sum of the maximum operating times for each divided path operation, is calculated (step S107).

After that, an evaluation value indicating the ratio of the reference maximum operating time to the comparative maximum operating time as a percentage is output to the display unit 30 (step S108). Further, the operation time of each axis of the shortest path operation and the operation time of each axis of the divided path operation are displayed, and at least the maximum operation time of each axis is highlighted (step S109), and this process is terminated.

When there are a plurality of evaluation target path operations to be evaluated, the processes from steps S104 to S109 are repeated.

<Example of path operation evaluation processing>
FIG. 4 is a diagram showing a maximum axial speed and a maximum unit operating time of each axis of the robot arm 5. Further, FIG. 5 is a diagram showing the postures of the work points P1 and P2 in the pass operation L0, which is the shortest path operation, the absolute value of the change amount of each axis, and the operation time. Further, FIG. 6 is a diagram showing the postures of the work points P1 and P2 and the relay work point P10 in the pass operation L10, which is the pass operation to be evaluated, the absolute value of the change amount of each axis, and the operation time. Further, FIG. 7 is a diagram showing the operation time and the evaluation value of each axis of the pass operation L0, the divided path operation L1, and the divided path operation L2.

As shown in FIG. 4, the maximum axial speed of each axis of the robot arm 5 is different, and the maximum unit operating time is also different depending on the maximum axial speed.

As shown in FIG. 5, the reference maximum operating time T0 of the shortest path operation is 0.85 (sec) of four axes, which is the maximum operating time of the operating times of each axis between the work points P1 and P2. To. In the shortest path operation, the operation time of the entire robot arm 5 is determined by the operation time of the four axes.

On the other hand, as shown in FIG. 6, in the calculation of the comparative maximum operating time T10, first, 0.7 (sec) of the four axes, which is the maximum operating time of the operating times of each axis of the divided path operation L1, is the divided path. It is extracted as the maximum operating time T1 of the operation L1. Further, 0.6 (sec) of one axis, which is the maximum operating time of each axis of the divided path operation L2, is extracted as the maximum operating time T2 of the divided path operation L2. Then, the sum of the maximum operating time T1 and the maximum operating time T2 is calculated as the comparative maximum operating time T10. In the divided path operation L1, the operating time of the entire robot arm 5 is determined by the operating time of the four axes, and in the divided path operation L2, the operating time of the entire robot arm 5 is determined by the operating time of one axis. Therefore, the comparative maximum operating time T10 is the sum of the maximum operating time T1 and the maximum operating time T2, that is, 1.3 (sec).

As shown in FIG. 7, the path operation evaluation unit 63 calculates an evaluation value indicating the ratio of the reference maximum operation time T0 to the comparative maximum operation time T10 as a percentage. The evaluation value is (0.85 / 1.3) × 100 = 65.4 (%). As for the evaluation value, the larger the value, the shorter the pass operation time, so that the evaluation value is evaluated as appropriate.

The path operation evaluation unit 63 includes the operation time of each axis of the path operation L0, which is the shortest path operation, the operation time of each axis of the divided path operation L1 of the path operation L10, which is the path operation to be evaluated, and the operation of the divided path operation L2. The time, the reference maximum operating time T0, the comparative maximum operating time T10, and the evaluation value are displayed on the display unit 30. At this time, the axes (4 axes, 4 axes, 1 axis) from which the reference maximum operation time T0, the maximum operation time T1, and the maximum operation time T2 in the path operation L0, the division path operation L1, and the division path operation L1 are extracted, and their operations Highlight time.

As a result, the program creator can evaluate the evaluated path operation L10 in terms of time based on the value of the evaluation value, and the highlighting makes it easy to axis the neck that lengthens the operation time of the pass operation. It can be found, and the position and orientation of the relay work point P10 can be adjusted to create a more optimum path operation to be compared.

In the above embodiment, the program creation system adopting the offline teaching method has been described, but the program creation system adopting the manual teaching method using the actual robot can also be applied. In this case, the path operation evaluation unit 63 will be mounted on the control device 3.

Further, each configuration shown in the above-described embodiment is a schematic function, and does not necessarily have to be physically illustrated. That is, the form of distribution / integration of each device is not limited to the one shown in the figure, and all or part of the device is functionally or physically distributed / integrated in an arbitrary unit according to various loads and usage conditions. Can be configured.

The robot program evaluation device, the robot program evaluation method, and the robot program evaluation program of the present invention change the posture of the robot between work points when creating an operation program of a robot that drives a plurality of axes of a robot arm to perform work. This is useful when evaluating path behavior including.

1 Robot system 2 Robot 3 Control device 4 Operation program 5 Robot arm 6 Welding gun 10 Robot program evaluation device 20 Input unit 30 Display unit 40 Communication unit 50 Storage unit 51 CAD data 52 Robot software 60 Control unit 61 Program creation unit 62 Simulation unit 63 Pass operation evaluation unit 100 Body 101 Interference area L0, L10 Pass operation L1, L2 Divided path operation P1, P2 Work point P10 Relay work point T0 Reference maximum operation time T1, T2 Maximum operation time T10 Comparison maximum operation time

Claims (5)

A robot program evaluation device that evaluates a path motion including a change in the posture of the robot between work points when creating a motion program of a robot that drives a plurality of axes of a robot arm to perform work.
At the maximum operation time of each operation time corresponding to the absolute value of the amount of change of each axis with respect to the shortest path operation that directly operates from the posture of the current work point, which is the tip work position of the robot arm, to the posture of the next work point. A certain reference maximum operation time is calculated, and an evaluated pass operation via one or more relay work points whose postures are set is formed between the current work point and the next work point. The maximum operation time of each operation time corresponding to the absolute value of the change amount of each axis is obtained for each of the plurality of division path operations in which the evaluation target path operation is divided by the relay work point, and the maximum operation time of each division path is calculated. A robot program creation device characterized in that the sum is calculated as a comparative maximum operating time, and the magnitude of the magnitude relationship between the reference maximum operating time and the comparative maximum operating time is output as an evaluation value of the evaluated path operation. .. The robot program evaluation device according to claim 1, wherein the evaluation value indicates the ratio of the reference maximum operating time to the comparative maximum operating time as a percentage. Claim 1 or claim 1, wherein the evaluation value, the operation time of each axis of the shortest path operation, and the operation time of each axis of the divided path operation are displayed, and at least the maximum operation time of each axis is highlighted. 2. The robot program evaluation device according to 2. This is a robot program evaluation method for evaluating a path motion including a change in the posture of the robot between work points when creating a motion program of a robot that drives a plurality of axes of a robot arm to perform work.
The maximum operating time of each operating time corresponding to the absolute value of the amount of change of each axis with respect to the shortest path operation that directly operates from the posture of the current working point, which is the tip working position of the robot arm, to the posture of the next working point A reference calculation step that calculates a certain reference maximum operating time, and
Between the current work point and the next work point, an evaluated pass operation is formed via one or more relay work points whose postures are set, and the relay work point causes the evaluated path operation. For each of the multiple divided path operations, the maximum operation time of each operation time corresponding to the absolute value of the change amount of each axis is obtained, and the sum of the maximum operation times of each division path is calculated as the comparison maximum operation time. Target calculation steps and
A robot program evaluation method including an evaluation step that outputs the magnitude of the magnitude relationship between the reference maximum operation time and the comparison maximum operation time as an evaluation value of the evaluation target path operation. A robot program evaluation program that evaluates a path motion including a change in the posture of the robot between work points when creating an motion program of a robot that drives a plurality of axes of a robot arm to perform work.
At the maximum operation time of each operation time corresponding to the absolute value of the amount of change of each axis with respect to the shortest path operation that directly operates from the posture of the current work point, which is the tip work position of the robot arm, to the posture of the next work point. A standard calculation procedure for calculating a certain standard maximum operating time, and
Between the current work point and the next work point, an evaluated pass operation is formed via one or more relay work points whose postures are set, and the relay work point causes the evaluated path operation. For each of the multiple divided path operations, the maximum operation time of each operation time corresponding to the absolute value of the change amount of each axis is obtained, and the sum of the maximum operation times of each division path is calculated as the comparison maximum operation time. Target calculation procedure and
A robot program evaluation program characterized in that a computer executes an evaluation procedure that outputs the magnitude of the magnitude relationship between the reference maximum operation time and the comparison maximum operation time as an evaluation value of the evaluation target path operation.

Images