JP4829151B2 - Robot program evaluation / correction method and robot program evaluation / correction device - Google Patents

Description

  The present invention relates to a robot program evaluation / correction method and a robot program evaluation / correction apparatus for correcting a robot operation program so that a robot performs a desired operation.

  Generally, robot operation programs created off-line are rarely used in the field as they are, and are used after being modified. This is because the relative positional relationship between the workpiece and the robot, the posture of the robot, and the like are slightly different between the offline world and the online (on-site) world, causing a shift. The work for correcting the operation program may include work for correcting a shift in the operation path in addition to work for correcting the speed command and acceleration command for the servo motor.

  When correcting the speed command or acceleration command of the operation program, check the load of the servo motor and use the teaching operation panel on site to check the duty (average value of one work cycle as a percentage of the limit value of the current value). While correcting the speed command and acceleration command.

  The movement path deviation is a deviation that occurs between the target movement path of the robot and the actual movement path. To correct this deviation, the actual position obtained by touching up the target position of the workpiece with the robot. The target movement path is set while shifting the teaching point defined on the screen in a direction that is gradually approaching the point. Alternatively, as an example of another method, the teaching point is shifted by multiplying the target position from the right by a unit difference matrix obtained from the difference between the teaching point at the target position and the teaching point actually touched. Make corrections.

  Patent Documents 1 and 2 are known as examples of known robot program evaluation / correction devices. In addition, software “Robo Guide” (registered trademark) provided by the present applicant is commercially available as software for operating this type of correction device.

JP 2005-66797 A Japanese Patent Laid-Open No. 2005-22062

  However, the work to correct the deviation of the movement path on site is a careful work to prevent interference, and the teaching point with a large deviation specified on the movement path is touched up and shifted for each teaching point. There is a problem that it takes a lot of time to construct a robot production system.

  Further, the work of correcting the program speed command and the acceleration command for the servo motor of the robot while checking the duty at the site has a problem that it takes a lot of trial and error, and takes a lot of man-hours.

  Accordingly, an object of the present invention is to provide a robot program evaluation / correction method and a robot program evaluation / correction device that can easily evaluate and correct an operation program of a robot created offline in a short time. .

In order to solve the above problem, the invention of claim 1 of the present invention is a robot program evaluation / correction method for correcting an operation program of a robot so that the robot performs a desired operation. Calculating and recording the amount of deviation between the target teaching point on the motion path and the pseudo teaching point on the pseudo motion path by simulation corresponding to the target teaching point, and whether or not the target teaching point should be corrected If the deviation amount as an evaluation function for evaluating the deviation exceeds an allowable value, and the deviation amount is larger than the allowable value , the pseudo teaching is performed with a predetermined change width so that the deviation amount becomes smaller. shifting the teaching points in the operating program corresponding to the point repeats the simulation run until the displacement amount becomes smaller than the allowable value, corresponding to the pseudo teaching point the Characterized in that it comprises a modifying the teaching point in the work program, the.

  According to a second aspect of the present invention, in the first aspect of the present invention, by calculating the load of a motor that drives an operating part of the robot by the simulation, an evaluation function is used to determine whether the motor load exceeds an allowable value. And further evaluating.

The invention of claim 3 is a robot program evaluation / correction device for correcting an operation program of a robot, comprising a computer having a simulation function for confirming the operation of the robot, the computer comprising: Storage means for calculating and storing a deviation amount between a target teaching point on a target motion path and a pseudo teaching point on a pseudo motion path by simulation corresponding to the target teaching point, and whether the target teaching point should be corrected Tests whether the amount of deviation of an evaluation function for evaluating the whether is greater than the allowable value, when the shift amount is greater than the allowable value, a predetermined change width as the displacement amount is small, the shifting the teaching points in the operating program corresponding to the pseudo teaching point, repeat the simulation until the displacement amount becomes smaller than the allowable value Run, characterized in that it comprises a correction means for correcting the teaching points in the operating program corresponding to the pseudo teaching point.

  According to a fourth aspect of the present invention, in the invention according to the third aspect, the computer calculates a load of a motor that drives an operation part of the robot by the simulation, and the load of the motor has an allowable value. Determining means for evaluating whether or not the value exceeds the value by an evaluation function.

  According to the first aspect of the present invention, the deviation amount between the target teaching point and the pseudo teaching point is stored in the first step, and the simulation is repeatedly executed until the deviation amount becomes smaller than the allowable value in the second step. Since the teaching points can be corrected, the teaching point of the operation program can be corrected in a short time compared with the case where a large number of teaching points are corrected so that the target operation path and the pseudo operation path coincide with each other. It can be performed. Thereby, the setup time of the robot in the field can be significantly shortened.

  According to the second aspect of the present invention, it is possible to evaluate the load of the servo motor offline (desktop), and based on this evaluation, the quality of the operation program can be determined from the viewpoint of the load. For this reason, compared with the case where an actual motor load is measured and evaluated in the field, the operation program can be corrected in a short time, and the robot setup time in the field can be shortened.

  According to the third aspect of the present invention, the amount of deviation between the target teaching point and the pseudo teaching point is stored by the storage means, and the computer simulation is repeatedly executed by the correcting means until the deviation amount becomes smaller than the allowable value. Since the correction is corrected, the teaching point of the operation program can be corrected in a shorter time compared with the case where a large number of teaching points are corrected so that the target operation path and the pseudo operation path coincide with each other. Thereby, the setup time of the robot in the field can be significantly shortened.

  According to the fourth aspect of the invention, the computer includes the load calculating means and the determining means, so that the load of the servo motor can be evaluated off-line (desktop). Therefore, the quality of the operation program can be determined. For this reason, compared with the case where an actual motor load is measured and evaluated in the field, the operation program can be corrected in a short time, and the robot setup time in the field can be shortened.

  Specific examples of embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a system configuration diagram of a robot system including a robot program evaluation / correction apparatus according to the present invention.

  In FIG. 1, 7 is a computer included in the robot program evaluation / correction device 2, 8 is an input device such as a keyboard and mouse connected to the computer, and 9 is an output device connected to the computer. Reference numeral 3 denotes a controller for controlling the operation of the robot by a robot operation program, 4 denotes an industrial robot as a control target, and 5 denotes a teaching device used for teaching a teaching point of the robot. Note that various robots having a plurality of motion axes can be applied to the robot 4.

  The robot program evaluation / correction device 2 according to the present invention includes at least a computer 7, an input device 8, and an output device 9, and is an apparatus that can correct an operation program created offline. The robot program evaluation / correction device system 1, the controller 3, the robot 4, and the teaching device 5 constitute a robot program evaluation / correction device system 1.

  The output device 9 of the robot program evaluation / correction device 2 is a display as a display device, and a robot 4, a workpiece (not shown) as a processing target, and peripheral devices (not shown) around the robot 4. ) And other image data. The computer 7 can perform a simulation of the robot 4 together with the output device 9 based on the operation program. The simulation is performed to evaluate and correct the robot operation program, and simulates the robot according to a designated movement command.

  As shown in FIG. 2, the robot program evaluation / correction device 2 (computer 7A) according to the first embodiment is capable of correcting teaching points on the operation path of the operation program in a short time. The read operation program is displayed on the screen, the operation unit specifying means 10 for specifying the operation part of each operation axis, the path specifying means 11 for storing and specifying the target operation path of the actual system, and the robot A deviation amount designation means 12 for designating a deviation amount between an arbitrary target teaching point on the target movement path 4 and a pseudo teaching point on the pseudo movement path by computer simulation corresponding to the target teaching point; Simulation means 13 for performing, recording means 14 for recording the elapsed time and the position / posture of the robot 4 at that time from the simulation result, The storage means 15 for calculating and storing the deviation amount between the target teaching point and the pseudo teaching point from the simulation result, and evaluating whether or not the deviation amount is larger than the allowable value are evaluated by a known evaluation function. Correction means 16 that corrects the teaching point by repeatedly executing the simulation until the deviation amount becomes smaller than the allowable value by shifting the teaching point so that the deviation amount becomes smaller when the deviation is larger. .

  FIG. 3 is a flowchart showing a flow of a correction method by the robot program evaluation / correction device. In FIG. 3, in step T <b> 1, a layout is created that three-dimensionally arranges image data of the robot 4, the workpiece, and peripheral devices on the screen of the output device 9. Image data such as the positions and postures of the robot 4, work, and peripheral devices is created by reading graphic information, arrangement information, and the like from a CAD device or the like.

  In step T2, an operation program associated with the robot 4, the workpiece, and the peripheral device is created on the screen of the output device 9. In steps T3 to T5, program correction conditions are set. Specifically, the motion part of each motion axis of the robot 4 is designated (corresponding to the motion part designating means 10 of the robot program evaluation / correction device), the program execution line to be displayed on the screen is designated, the target The motion path is specified as a cubic curve (corresponding to the robot program evaluation / correction apparatus path specifying means 11), or the allowable deviation from the target path (corresponding to the robot program evaluation / correction apparatus deviation amount specifying means 12). ).

  In step T6, an operation program is executed by the simulation means 13 to simulate the robot operation. In step T7, the current position of each operation axis for each unit time is recorded together with the elapsed time (the teaching point can be referred from the execution line). Suppose). This step corresponds to the recording means 14 of the robot program evaluation / correction device.

  As described above, according to the present embodiment, the teaching point of the operation program is corrected in a short time compared to the case where a large number of teaching points are corrected so that the target motion path and the pseudo motion path coincide with each other at the site. As a result, the setup time of the robot 4 at the site can be greatly shortened. Therefore, a robot production system can be easily constructed at the production site, and a change in the production system can be flexibly handled.

  Next, a second embodiment of the robot program evaluation / correction apparatus 2 having the computer 7B will be described. The robot program evaluation / correction device 2 (computer 7B) of this embodiment corrects the command speed and the command acceleration so that the cycle time of the robot 4 (see FIG. 1) is minimized within the allowable range of the motor load. As shown in FIG. 4, a designating unit 20 for designating an operation part such as an upper arm or a forearm of a 6-axis articulated robot and a load of a servo motor that drives the operation part, and an operation program Simulation means 21 for performing simulation, load calculation means 22 for calculating the load of the servo motor, storage means 23 for storing the command speed and command acceleration for the servo motor and the motor load in association with each other in time series, and the load on the servo motor Determine whether the load on the servo motor of each motion axis is within the allowable range using a well-known evaluation function to evaluate It includes a constant unit 24.

  FIG. 5 is a flowchart showing a flow of an evaluation / correction method performed by the robot program evaluation / correction device 2 of FIG. In FIG. 5, in step S <b> 1, a layout is created that three-dimensionally arranges image data of the robot 4, work, and peripheral devices on the screen of the output device 9 (see FIG. 1). Image data such as the positions and postures of the robot 4, workpieces, and peripheral devices are created by reading graphic information, arrangement information, and the like from a CAD device or the like.

  In step S <b> 2, an operation program associated with the robot 4, the workpiece, and the peripheral device is created on the screen of the output device 9. In step S3, program correction conditions are set (corresponding to the designation means 20 of the robot program evaluation / correction device 2). Specifically, the operating part of the robot 4 is specified, the allowable load of the servo motor is specified, the program execution line to be displayed on the screen is specified, the program command speed or command acceleration to be corrected is specified. , A correction range δ for changing the command speed and command acceleration for each line of the program, or an initial value of the cycle time.

In step S4, the motion program is executed by the simulation means 21, the robot motion is simulated, and the current position of each motion axis per unit time is recorded together with the elapsed time. In step S5, the load torque of the servo motor is calculated from the relationship between the elapsed time and position of each motion axis of the robot 4 as a simulation result (corresponding to the load calculation means 22 of the robot program evaluation / correction device 2). ).
Load torque = Newton oiler torque + friction force + rotor inertia driving force

  In step S6, the program command speed and command acceleration for each line and the motor load of each motion axis are stored in association with each other in time series (corresponding to the storage means 23 of the robot program evaluation / correction device 2). In step S7, it is determined by a well-known evaluation function whether the motor load of each operation axis is equal to or less than the allowable value for each line of the operation program, and whether it is within the allowable range for each line when the simulation is first executed. Record how. Here, the evaluation function is a weighted function as an evaluation criterion used for determining the load of the servo motor or optimizing the relative positional relationship between the robot 4, the workpiece, the peripheral devices, and the like. Say. For example, there is an apparatus described in Japanese Patent Application Laid-Open No. 2005-22062 as an apparatus for evaluating the operation of a robot using an evaluation function.

  FIG. 6 is a configuration diagram showing a third embodiment of the robot program evaluation / correction apparatus 2. The robot program evaluation / correction device 2 (computer 7C) of this embodiment is obtained by adding correction means 25 for correcting the command speed and command acceleration to the robot program evaluation / correction device 2 of the second embodiment.

  FIG. 7 is a flowchart showing the flow of the correction method by the robot program evaluation / correction device 2 of FIG. This flowchart is obtained by adding step S8 to the flowchart of FIG. In step S8, when it is determined in step S7 that the motor load of each operation axis is within the allowable range, the command speed, command acceleration and execution time for each row at this time, and the total cycle time are calculated. If it is shorter than the recorded cycle time, record it. Then, the correction width δ is added to the command speed and command acceleration of the target program line, and the simulation is repeated again. When it is determined that the motor load of each operation axis is not within the allowable range, the correction width δ is subtracted from the command speed and command acceleration of the target program line. If it is not within the allowable range when first executed, δ is subtracted from the speed and acceleration until the motor load is within the allowable range. When it is within the allowable range when it is first executed, the change width δ is added to the speed and acceleration until the allowable range of the duty is exceeded or the upper limit of the command speed and the command acceleration is reached.

  The evaluation is performed for each row, and if it is not within the allowable range when it is first executed, the row change is terminated when the duty is within the allowable range. Otherwise, the simulation in step S4 is performed and the evaluation process is repeated. . When it is within the allowable range when it is first executed, the line change is finished when the allowable range of the duty is exceeded or the command speed and the command acceleration are reached. Otherwise, the simulation of step S4 is performed, Repeat the evaluation process. This operation is repeated until all the lines in the program have been processed. In this way, the maximum command speed and command acceleration can be obtained within the allowable range of the motor load.

  As described above, according to the second and third embodiments, the load on the servo motor can be evaluated offline (on the desk), and the quality of the operation program can be determined based on this evaluation. Compared with the case where the motor load is measured and evaluated, the operation program can be corrected in a shorter time, and the setup time of the robot on site can be shortened. Further, according to the second embodiment, the operation program can be corrected in a short time compared to the case where the command speed and command acceleration of the operation program are corrected so that the cycle time is minimized at the site. As a result, the setup time of the robot 4 at the site can be greatly shortened. Further, when multi-product production is performed using the same robot 4, it is possible to greatly reduce the trouble of correcting the operation program.

  In addition, this invention is not limited to the said embodiment, A various change can be implemented. In this specification, although 1st, 2nd, 3rd embodiment is described separately, it is also possible to combine these embodiment. For example, it is possible to improve the consistency between the computer model and the actual system by implementing the second embodiment after implementing the first embodiment and correcting the deviation of the operation path. .

1 is a system configuration diagram of a robot program evaluation / correction device system including a robot program evaluation / correction device according to the present invention. It is a block diagram which shows 1st Embodiment of a robot program evaluation and correction apparatus. It is a flowchart which shows the flow of the correction method by the robot program evaluation and correction apparatus shown in FIG. It is a block diagram which shows 2nd Embodiment of a robot program evaluation and correction apparatus. It is a flowchart which shows the flow of the correction method by the robot program evaluation and correction apparatus shown in FIG. It is a block diagram which shows 3rd Embodiment of the robot program evaluation and correction apparatus. It is a flowchart which shows the flow of the correction method by the robot program evaluation and correction apparatus shown in FIG.

Explanation of symbols

2 Robot program evaluation / correction device 7, 7A to 7C Computer 8 Input device 9 Output device 10, 20 Operation designation means 11 Path designation means 12 Deviation amount designation means 13, 21 Simulation means 14 Recording means 15, 23 Storage means 16 Correction means 22 Load calculation means 24 Determination means 25 Correction means

Claims (4)

A robot program evaluation / correction method for correcting an operation program of a robot so that the robot performs a desired operation,
Calculating and recording a deviation amount between a target teaching point on the target movement path of the robot and a pseudo teaching point on a pseudo movement path by simulation corresponding to the target teaching point;
It is evaluated whether a deviation amount as an evaluation function for evaluating whether or not the target teaching point should be corrected exceeds an allowable value. If the deviation amount is larger than the allowable value, the deviation amount is reduced. The teaching point in the operation program corresponding to the pseudo teaching point is shifted by a predetermined change width, the simulation is repeatedly executed until the shift amount becomes smaller than the allowable value, and the pseudo teaching point corresponding to the pseudo teaching point is Correcting the teaching points in the motion program ;
A robot program evaluation / correction method comprising: Calculating a load of a motor that drives an operation part of the robot by the simulation;
Evaluating whether the load of the motor exceeds an allowable value by an evaluation function;
The robot program evaluation / correction method according to claim 1, further comprising: A robot program evaluation / correction device for correcting a robot operation program,
A computer having a simulation function for confirming the operation of the robot;
Storage means for calculating and storing a shift amount between a target teaching point on the target motion path of the robot and a pseudo teaching point on a pseudo motion path by simulation corresponding to the target teaching point;
It is evaluated whether a deviation amount as an evaluation function for evaluating whether or not the target teaching point should be corrected exceeds an allowable value. If the deviation amount is larger than the allowable value, the deviation amount is reduced. The teaching point in the operation program corresponding to the pseudo teaching point is shifted by a predetermined change width, the simulation is repeatedly executed until the shift amount becomes smaller than the allowable value, and the pseudo teaching point corresponding to the pseudo teaching point is A robot program evaluation / correction device comprising: correction means for correcting teaching points in an operation program . A load calculating means for calculating a load of a motor for driving the moving part of the robot by the simulation;
A determination means for evaluating by an evaluation function whether the load of the motor exceeds an allowable value;
The robot program evaluation / correction device according to claim 3, further comprising:

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