JPH05301196A - Robot control system parameter regulating device - Google Patents

Abstract

PURPOSE:To prevent a robot from entering a dangerous operation in an automatic regulation by finding beforehand a scope the robot can enter a dangerous operation condition when the robot operates actually, and setting the scope of parameters to be regulated in the scope other than the dangerous scope. CONSTITUTION:A controller is composed of a main member 50, a servo member 60, and a driver member 70. A CRT 14 and a keyboard 15 are connected to the main member 50. A motor 3 and an encoder 4 are connected to the driver member 70. Furthermore, the interfaces 56 and 65 of the main member 50 and the servo member 60 are the common memory, and the interfaces 66 and 75 of the servo member 60 and the driver member 70 are composed of a two port RAM respectively. In this case, since the scope of parameter to generate an abnormal hunting or an oscillation condition is found by changing the parameter without moving the robot, the operation condition of the robot is evaluated and decided by the parameter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention In a robot driven by an NC servomotor, the present invention adjusts parameters including a gain of a control system so that the operation of a robot arm which moves to a target value is in an appropriate operating state. The present invention relates to a robot control system parameter adjusting device.

[0002]

2. Description of the Related Art In order to obtain an appropriate operation state of a robot driven by an NC servo motor as shown in FIG. 4, it is necessary to adjust parameters including a gain of a robot control system. .. Therefore, while observing the operation of the robot using a measuring device such as a sensor, a person determines and adjusts whether or not the operation state is appropriate by changing the parameter. There is also an adjusting method in which the parameter value is determined by measuring the frequency response of the robot.

Further, regarding the automatic adjustment method, means for automatically measuring the above-mentioned frequency response, obtaining the transfer function thereof, and determining a theoretically proper gain based on the result (Japanese Patent Laid-Open No. 2-253303). (Refer to Japanese Patent Application Laid-Open No. 2-284831) or the like, or a means for determining while determining the proper or improper depending on the presence or absence of overshoot or the presence or absence of vibration while observing the actual operating state in order from the standard parameter. there were.

[0004]

However, in the above-mentioned conventional example, while observing the actual operation of the robot with a measuring device such as a sensor, the parameters are changed to determine whether or not the operation is appropriate by a person. Therefore, it takes a lot of time and effort to adjust the parameters, and further, the judgment by the person is ambiguous, and there is the variation by the operator.

Even after the introduction of the factory, it was difficult to adjust the parameters each time the magnitude of the load grasped by the hand changed.

The adjustment based on the frequency response does not always match the theoretical value and the actual value, that is, the operating state in which the robot is actually operated, and there are cases where the condition is unsatisfactory. In order to automatically measure this frequency response and determine a theoretically proper value, the program for the automation needs a considerably large memory capacity. Also, in the latter of the automatic adjustment methods, the appropriate values of the parameters vary considerably depending on the type of motor and the size of the load, so standard parameters are not set, and it is not possible to set them. there were. In addition, when judging whether there is an overshoot amount or not, in some cases it is better to have a faster arrival time even if the overshoot amount is large. Had some drawbacks, such as being dangerous when making that decision.

[0007] Therefore, an object of the present invention is to provide a device which ensures safety in the actual driving of the robot and can quickly set an appropriate operating range of the robot.

[0008]

Therefore, according to the present invention, there is provided a parameter adjusting device for a robot control system, that is,
A controller capable of setting the parameters of the robot control system from the outside is connected to a robot driven by an NC servomotor, and the controller controlling the movement of the robot to the input target position is adjusted to a predetermined parameter value. In the robot control system parameter adjusting device, the parameters can be changed without moving the robot in the area of the parameter that causes abnormal hunting or oscillation, or without moving the robot as much as the actual movement.
As a means for finding out, by providing a means for evaluating and judging the operating state of the robot with given parameters by an internal device, it is possible to avoid a state in which the robot becomes dangerous in adjusting the parameter value. Then, set the values of the parameters within the range of parameters that avoid the dangerous state of this robot in the controller of the robot one after another, and actually control the operation of the robot by the controller having the set parameter values. Then, the arrival time to the target position, the overshoot amount, the settling time, the settling accuracy, etc. can be recorded one after another. In addition, when operating the actual robot,
The necessary criteria for movement such as movement amount are set so that the movement of the controlled object as a result can be judged to be proper or unsuitable. Time, overshoot amount, settling time, settling accuracy, etc. are set based on the judgment, and if it is judged to be improper, the next parameter is immediately given to the control device and the time taken for the adjustment. To save money. If it is judged to be appropriate, each data at that time is recorded and saved, and can be displayed if necessary.

[0009]

When a parameter is set in the control device that can cause an abnormal hunting or oscillation state of the robot, the action of the abnormal hunting or oscillation state appears by moving the robot slightly, without moving it to the same extent as in reality. In addition, it is possible to find out whether or not the vibration oscillates while the servo is locked, that is, even if the controlled object is not moved as a result. It is possible to find out what is dangerous when the value of is before the investigation to see its operating state by moving it to the same extent as in reality. The present invention allows the means for finding this to be done by an internal device.

Therefore, when operating the actual robot to record various data or adjust appropriate parameters within a range of parameters that avoids a dangerous state of the robot, the robot is in a dangerous state. Never becomes. Then, appropriate parameters can be automatically determined so that the internal device can automatically determine the suitability of the parameters to be set, and this can be recorded.

[0011]

EXAMPLES Examples of the present invention will be described below.

FIG. 4 is a diagram showing an example of the configuration of a robot driven by an NC servo motor and a control device therefor, which is the subject of the present invention.

In FIG. 4, the 4-axis horizontal articulated robot body 1 includes a first axis arm 2, a second axis arm 5 and a hand 8.
It is composed of The first axis arm 2 includes the first axis motor 3
Thus, it is driven via a speed reducer (not shown). The first axis motor 3 is equipped with a first axis encoder 4 and feeds back the current position to the controller 13. Similarly, the Z axis direction and the S axis direction of the second axis arm 5 and the hand 8 are the second axis motor 6, the Z axis motor 9, and the S axis motor 11 respectively.
Driven by, each equipped with an encoder. That is, 7 is a second axis encoder, 10 is a Z axis encoder, and 12 is an S axis encoder. The robot 1 is connected to the controller 13 and controls the motor of each axis. The controller 13 has a CRT 14 and a keyboard 15
Are connected.

FIG. 2 shows an internal block diagram of the controller 13. The controller 13 includes a main unit 50, a servo unit 60, and a driver unit 70. The interface (IF) 55 of the main unit 50 is connected to the CRT 14 and the keyboard 15, and the pulse width of the interface (IF) 74 of the driver unit 70. The motor 3 is connected to a power amplifier capable of modulation (PWM), and the current position from the encoder 4 is connected to a counter 76. The interfaces (IF) 56 and 65 of the main unit 50 and the servo unit 60 are shared memories, and the servo unit 60 and the driver unit 7 are
0 interface (IF) 66, 75 is 2 port R
It is composed of AM.

Further, the CPUs 51, 61 and 7 are provided in the respective units.
1, ROM 52, 62, 72, RAM 53, 63, 73
The main unit 50 has an I / O port 54.

The main section 50 controls the entire sequence, the servo section 60 controls the position of the motor 3, and the driver section 70 controls the speed and current.

For example, a case where the first axis arm 2 of the robot is moved from the current position to a certain position P (1) will be described. FIG. 3 shows P in the controller 13 (FIG. 4).
The I control system 100 is shown as a block diagram. From the position data of P (1) in the main section 50 shown in FIG.
Interface 5 to move to that position
It is sent to the servo unit 60 through 6, 65, and the servo unit 60
Then, based on the position data, the position deviation 122 (in FIG. 6) 60 for each sampling time is moved so as to move so as to obtain the theoretical value 501 of the velocity waveform in FIG.
3: Command position 120 (601) and current position 121 (60
The difference from 2) is multiplied by the position gain (Kp) by the multiplier 101 and the speed command 123 is sent to the driver unit 70 through the interfaces 66 and 75 (FIG. 3). In the driver unit 70, the current speed 124 obtained by differentiating the output 126 of the encoder 4 by the differentiator 109 and the speed deviation 125 obtained from the speed command 123 are multiplied by the speed gain (Kv) by the multiplier 102. A value 127 obtained by integrating the deviation 125 in the integrator 104 is multiplied by a constant (Iv) in the multiplier 105, and these are combined to form a current command 128. Then, the current deviation 130 from the current value 129 from the current detector 110 is multiplied by the current gain (K
i) Multiply, on the other hand, the current deviation 130 is integrated by the integrator 106 in the same manner as the speed deviation, and the output 131 is multiplied by the multiplier 107.
, The constant (Ii) is multiplied, and the sum of these is increased by the power amplifier of the interface 74 before the motor 3
It is configured to output to. And the motor 3
Is detected by the encoder 4 and compared with the target position command 120 by the counter 76 as the current position signal 121, and the speed command 1 is differentiated by the differentiator 109 as described above.
Compared with 23.

In the present invention, in the main section 50, a system program is incorporated into the ROM 52, and a condition setting program which requires rewriting is incorporated into the RAM 53, various condition settings are made from the keyboard 15, and parameters (Kp and Kv in the figure) are set. , Ki, Iv, Ii) are set. All these parameters, namely Kp, Kv, ki,
All of Iv and Ii may be adjustable, but if Iv and Ii are set to appropriate constants, it becomes easy to adjust each parameter.

In the servo unit 60, the position deviation is calculated and the arrival time (a), overshoot amount (b) and settling shown in FIG. Time (c),
The steady-state deviation, that is, the settling accuracy (d) is measured using the timer 64 to enable recording, and it is determined whether the condition set by the main unit 50 is satisfied. The conditions are, for example, a movement of 50,000 pulses (500 mm, angle of 90 °), a = 0.49 sec, b = 20 pulses (0.2 mm),
It is possible to set c = 0.2 sec and d = 2 pulses.

The RAM 72 in the driver section 70
In the RAM 73, programs for positioning control, speed control, and current control are stored, and in the RAM 73, robot operation programs and the like are stored.

The signal from the encoder 4 is sent to the driver unit 7
The current position is received by the counter 76 within 0 and sent to the servo unit 60 through the interfaces 75 and 66.
FIG. 1B shows a flowchart of the automatic adjustment method according to the present invention.

The procedure of this parameter automatic adjustment method is shown in FIG.
An explanation will be given based on (b).

First, the following procedure is performed for the first axis of the four axes of the robot shown in FIG. The conditions in the automatic adjustment program are set by the keyboard 15 in the main unit 50 (201). Next, the automatic adjustment program in the servo unit 60 is executed to find a parameter area that is in a hunting state or an oscillation state, and an upper limit value and a lower limit value that are ranges of each parameter are determined and set (20).
2). In this step 202, the parameters are arranged in a matrix, the parameters are sequentially set by giving a servo LOCK state or an extremely minute movement command, and the settling state at that time is monitored in the servo section 60 to determine a non-dangerous range. ..

The parameters are arranged in a matrix within a non-dangerous range, and are sequentially set (203). Therefore,
The motor 3 is actually operated once or a plurality of times (204),
The arrival time (a), the overshoot amount (b), the settling time (c), which serve as the judgment reference data in the servo unit 60,
Settling accuracy (d) is calculated for each operation (20
5). The judgment reference data is stored in the memory (RAM 63) (207), and is displayed as necessary after completion of the entire parameter range (208, 210, 209) (FIG. 1 (a)).
Further, it is judged in the servo unit 60 whether this judgment reference data satisfies the condition set in the main unit 50 (206). If the condition is not satisfied, the next parameter is immediately or repeated several times. If a value is set and the condition is satisfied, the above data and the value of the parameter at that time are stored in the RAM 63 (207), and it is checked whether the entire parameter range is completed (208). The data saved in the RAM 63 is displayed on the CRT 14 as a gain (209) (FIG. 1).
(B)). If the entire range is not finished in step 208, the parameter value is set to the next value (210) and the processes in steps 203 to 208 are repeated. (FIGS. 1 (a) and 1 (b)) Here, the condition is to determine the condition that "the data serving as the judgment standard is equal to or less than the minimum required value in the actual operation of the robot", that is, It can be said that there is no particular problem when the robot actually operates when the parameters satisfy all the conditions, and thus it can be said that the gain is appropriate. In this way the first
Each axis parameter can be adjusted to an appropriate gain.

Further, the conditions set in the main unit can be changed in various ways, and the operator can arbitrarily set the conditions as required.

In the other axes in FIG. 4, the Z axis, the S axis, and the S axis, the parameters of the position gain, the velocity gain, the velocity integration constant, the current gain, and the current integration constant, which are the parameters, are calculated by the same automatic adjustment method. A plurality or all can be adjusted to appropriate values.

[0027]

As described above, according to the present invention,
It is possible to prevent dangerous robot movement during automatic adjustment by finding in advance the range of parameters that can be adjusted when the robot actually moves and setting the range to remove that area. Since this can be prevented and the range can be narrowed, there is an effect that the time required for recording the set conditions and parameter values and automatically adjusting the parameter values can be shortened.

Then, the robot is actually moved to a target position under a certain operating condition and a certain parameter, and an arbitrarily set judgment criterion is set for the operating state so that the robot has a proper gain. Can be adjusted to an appropriate gain so that the actual operation of the above-mentioned operation satisfies an arbitrary criterion.

Further, the parameters can be automatically set from the outside, the operating state of the robot is measured and judged inside the device, and the automatic adjustment device that makes the parameter a proper gain a plurality of times for all the operations is set by the external adjustment device. There is an effect that an immediate gain can be easily adjusted without preparing a measuring instrument, and an appropriate gain including stability of robot operation can be automatically adjusted in a short time.

[Brief description of drawings]

FIG. 1 is a flowchart of a method for recording or automatically adjusting parameters according to the present invention. (A) is a flowchart mainly for recording parameters. (B) is a flowchart mainly for automatic parameter adjustment.

[Figure 2] Robot controller configuration diagram

[Fig. 3] Block diagram of PI control system in controller

FIG. 4 shows an example of a robot to which the present invention is applied and its control device.

FIG. 5 is a diagram showing the moving speed of the robot to a certain target position.

FIG. 6 is a diagram showing criteria for determining whether the parameters are proper.

[Explanation of symbols]

1 4 axis horizontal articulated robot main body 2 1 axis arm 3 1 axis motor 4 1 axis encoder 8 hand 13 controller 14 CRT 15 keyboard 50 main part 60 servo part 70 driver part 51, 61, 71 CPU 52, 62, 72 ROM 53 , 63, 73 RAM 64 timer 55, 56, 65, 66, 74, 75 interface 76 counter 100 PI control system 210-210 in controller Each step of flowchart

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G05D 3/12 305 V 9179-3H

Claims (7)

[Claims] 1. A controller for externally connecting a controller capable of setting parameters of a robot control system to a robot driven by an NC servomotor, and controlling the movement of the robot to move to an input target position is predetermined. In the parameter control device of the robot control system that is adjusted to the parameter value of, by changing the parameter in the area of the parameter that causes abnormal hunting or oscillation without changing the robot or moving the robot as much as the actual movement, As a means for finding, a robot control system characterized by providing means for evaluating and judging the operating state of the robot with given parameters, and making it possible to avoid a dangerous state of the robot in the adjustment of parameter values in advance. Parameter adjustment device. 2. The robot control system according to claim 1, further comprising means for successively setting parameter values avoiding a parameter value in a state in which the robot is in danger, which is found in the parameter adjusting apparatus, to the control device. By controlling the actual robot operation with the controller having the parameter values
A data recording device for adjusting a parameter value of a robot control system, characterized in that it has means for recording the arrival time to a target position at that time, the amount of overshoot, the settling time, the settling accuracy, etc. one after another. 3. The actual robot operation according to claim 2 is performed a plurality of times by a control device having the same set parameter value, and the arrival time to the target position, the overshoot amount, the settling time, A data recording device for adjusting a parameter value of a robot control system, comprising means for recording an average value such as settling accuracy. 4. A recorded data display device for adjusting a parameter value of a robot control system, comprising display means capable of displaying the data recorded according to claim 2 or 3 as required. 5. The robot control system according to claim 1, further comprising means for successively setting parameter values in the control device, avoiding parameter values in a state in which the robot is in danger, which is found in the parameter adjusting device. When operating an actual robot with a controller that has different parameter values,
When it is judged that the operation is performed with conditions related to movement such as speed / movement, etc., and the result of the movement of the controlled object is set to a criterion for distinguishing whether the movement is appropriate or not, An automatic parameter adjusting device for a robot control system, characterized in that the controller can be set to the next parameter value to be set at that time. 6. The determination criterion according to claim 5 is one or more of a set value of arrival time to a target position, an overshoot amount, a settling time, and a settling accuracy, and means for setting based on a combination including all of them is provided. An automatic parameter control device for robot control systems. 7. The means for allowing an operator to arbitrarily set the arrival time to the target position, the overshoot amount, the settling time, the value to which the settling accuracy should be set, and the combination thereof according to claim 6. An automatic parameter adjustment device for robot control systems.