JPH0724757A - Robot controller - Google Patents

Abstract

PURPOSE:To move an arm with less labor easily by controlling a control means when a manual switch is operated and controlling a servo motor by an integration term in a switch operation time. CONSTITUTION:This controller is provided with a subtracter 82 for finding out a velocity deviation eV by subtracting a present velocity Vfb from a velocity detector 80 based on the signal from a detector 20 from an order velocity VS and a control interruption part 84 based on the operation of a manual switch and a proportion calculation part 86 for calculating a proportion term VP by mutiplying the velocity deviation eV inputted through the control interruption part 84 by a velocity proportion gain KVP. The velocity deviation ev inputted through the control interruption part 84 is time-integrated by an integrator 88 and an integration calculation part 90 calculates an integration term Vi by multiplying this integrated value by a velocity integration gain Kvi. An adding machine 92 calculates an order value IS so as to output to a servo amplifier 70 by adding a proportion term VP to an integration term Vi. The servo amplifier 70 drives and controls a servo motor 10 based on this order value IS and moves a first arm to an order position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot controller which allows an operator to push and move an arm of a robot.

[0002]

2. Description of the Related Art Conventionally, in order to make a robot perform a certain work, it is necessary to command the movement of a robot arm. For example, in the case of performing an operation such as grasping an object existing at a certain position and placing it at another place, it is necessary to accurately teach the position where the object is grasped and the position where the object is placed. In that case, the arm is actually moved to that position and the position is taught. When teaching the operating position of this robot, the robot is moved by a jog operation with a remote control terminal device called a teaching box, or when the power source is turned off and the operator directly moves the robot arm by hand. was there.

In addition, there are cases where the arm of the robot interferes with the work and it is necessary to retract the arm to another position. Also in this case, similarly, there are cases in which the arm is moved by a jog operation in the teaching box and cases in which the operator directly moves the arm.

[0004]

However, in such a conventional device, when teaching the position by operating the keys of the teaching box, it takes a huge amount of time to perform a delicate positioning operation, and moreover, an accurate positioning operation is required. Is difficult to do.

For example, a work 42 having a positioning hole 40 as shown in FIG. 7 is shown in FIG.
A positioning pin 34 of the jig 32 is used by the articulated robot.
In case of inserting into the positioning pin 34, the jog command key 67 of the teaching box 66 is used to visually check the hole 40.
Move it so that it is directly above. Then, the positioning pin 34 is moved by moving the jog command key 67 in the vertical direction.
Fit in.

If the positioning pin 34 does not come in contact with the edge of the hole 40, the jog command key 67 is operated to correct the deviation. The jog command key 67 is repeatedly operated to repeatedly move the work 42 back and forth and to the left and right to determine the position. It took a huge amount of time to move.
Even if there is a slight deviation, if the work 42 is inserted into the positioning pin 34, the positioning pin 34 and the hole 40 may be twisted or the positioning pin 34 may be bent.
Alternatively, there is a problem that the hole 40 may be deformed.

When the arm is temporarily retracted to another position, the jog command key 67 is operated to move the arm. However, there are a plurality of jog command keys 67 depending on the number of servo motors and they are operated. Then, the arm has to be moved, and there is a problem that the operation is troublesome.

On the other hand, when the operator directly moves the arm, it is easy to perform a delicate positioning operation and to retract it to another position, but if the power source is cut off, the operator However, there is a problem in that the arm must be moved by hand to perform a positioning operation or to be moved to a position with a large distance while supporting the weight of the arm, which requires a large amount of labor to move the arm.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a robot controller capable of easily moving an arm with a small amount of labor in order to solve the above problems.

[0010]

In order to achieve such an object, the present invention has the following constitution as means for solving the problem. That is, as illustrated in FIG. 1, the servo motor M
1 has a detecting means M2 for detecting the position and speed of the arm driven by 1, and calculates a proportional term corresponding to the speed deviation between the command speed and the detected speed based on the command position and the position deviation between the detected positions. In addition, in the robot controller including the control means M3 for calculating the integral term according to the integral value of the speed deviation and performing feedback control of the servomotor M1 with the command value based on the proportional term and the integral term. A manual operation switch M4 is provided, and when the manual operation switch M4 is operated,
This is the configuration of the robot controller characterized in that it is provided with a manual operation control means M5 for controlling the control means M3 to control the servomotor M1 by the integral term when the switch is operated.

[0011]

In the robot controller having the above structure, when the manual operation switch M4 is operated, the manual operation control means M5 is provided.
Controls the control means M3 to control the servomotor M1 by the integral term when the manual operation switch M4 is operated. Therefore, since the servomotor M1 is controlled by the integral term, the operator can easily move the arm.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 2 is a schematic configuration diagram of a robot controller which is an embodiment of the present invention. Articulated robot body 1
Includes a movable table 2 supported so as to be horizontally movable, and the movable table 2 is configured to be reciprocated in the horizontal direction by a servo motor 4 (see FIG. 3). The servomotor 4 is provided with a detector 6 composed of a rotary encoder, and the detector 6 is configured to output a pulse signal according to the rotation of the servomotor 4.

One end of a first arm 8 is swingably supported on the movable table 2 and is configured to be driven to rotate by the rotation of a servo motor 10. Further, one end of the second arm 12 is swingably supported at the tip of the first arm 8, and is configured to be driven to rotate by the rotation of the servo motor 14. And the second arm 1
A hand 16 is swingably supported at the tip of the second member 2, and is configured to be rotated by the rotation of a servo motor 18.

Each of the servomotors 10, 14 and 18 has a detector 20 composed of a rotary encoder,
22 and 24 are provided, and the detectors 20, 22, and 24 are provided.
Are configured to output pulse signals corresponding to the rotations of the servomotors 10, 14, and 18, respectively.

Two chucks 26, 28 capable of gripping the outer circumference of the work 42 shown in FIG. 7 are attached to the hand 16 so as to be orthogonal to each other. Also,
A jig 32 is placed on a work table 30 arranged in the vicinity of the movable table 2, and a positioning pin 34 that can be fitted into a hole 40 of a work 42 is erected on the jig 32. ing.

Each of the servo motors 4, 10, 14, 18
The detectors 6, 20, 22, and 24 are connected to an electronic control circuit 50, and the electronic control circuit 50 includes the well-known CPU 5
2. The ROM 54 and the RAM 56 are configured as the center of a logical operation circuit, and an input / output circuit for performing input / output with the outside, here, an input circuit 58 and an output circuit 60 are connected to each other via a common bus 62.

The CPU 52 includes detectors 6, 20, 22,
A signal from the manual operation switch 64 provided on the second arm 12 facing the operator and a signal from the teaching box 6 are input from the input circuit 58.
The signal from 6 is input via the input circuit 58. on the other hand,
Based on these signals and the data in the ROM 54 and RAM 56 and the control program stored in advance, the CPU 52
Via the output circuit 60, each servo amplifier 68, 70,
A signal is output to 72, 74, and each servo motor 4, 10,
The robot body 1 is controlled by controlling 14 and 18.

The control processing performed by the electronic control circuit 50 is shown in a block diagram in FIG. A subtractor 7 for subtracting the current position Pfb detected by the detector 20 from the command position Ps to obtain a position deviation ep (= Ps-Pfb).
6 and a multiplication unit 78 that calculates the command speed Vs (= Kp * (Ps-Pfb)) by multiplying the position deviation ep by the position proportional gain Kp.

Further, the command speed Vs is subtracted from the current speed Vfb from the speed detector 80 based on the signal from the detector 20 to obtain a speed deviation ev (= Vs-Vfb).
2, the control interruption unit 84 based on the operation of the manual operation switch 64, and the speed deviation e input via the control interruption unit 84.
and a proportional operation unit 86 for calculating a proportional term Vp by multiplying v by a velocity proportional gain Kvp.

Further, an integrator 88 for time-integrating the speed deviation ev input via the control interruption unit 84, and an integration calculation unit 90 for multiplying the integrated value by the speed integration gain Kvi to calculate an integral term Vi. , And an adder 92 for adding the proportional term Vp and the integral term Vi to calculate the command value Is and outputting it to the servo amplifier 70. The block diagram is
Although the servo motor 10 of the arm 8 is taken as an example, the other servo motors 4, 14 and 18 are similarly configured.

Next, the control processing performed in the electronic control circuit 50 described above will be described with reference to the flowchart of FIG. The servo motor 10 of the first arm 8 will be described below.
, The other servo motors 4, 14,
The same applies to 18. First, the current position Pfb of the first arm 8 is calculated by adding the pulse signals from the detector 20.
Further, the current speed Vfb is detected from the number of pulses per unit time or the like (step 100. Hereinafter referred to as S100. The same applies hereinafter). Next, the mode selection key 66a of the teaching box 66 is used to determine which mode is selected.
Judgment is made depending on which one is selected (S1
10).

When the memory key 66b is selected, it is determined that the memory mode is selected, the preset program is read, and the next command position P at which the first arm 8 moves.
s is calculated (S120). This calculated command position Ps
From the current position Pfb detected by the processing of S100
To calculate the position deviation ep (= Ps-Pfb),
This position deviation ep is multiplied by the position proportional gain Kp to calculate the command speed Vs (= Kp * (Ps-Pfb)) (S1).
30).

Next, the current speed Vfb detected by the processing of S100 is subtracted from the commanded speed Vs to obtain the speed deviation ev (= Vs-Vfb) (S140). continue,
The speed deviation ev is multiplied by the speed proportional gain Kvp to calculate the proportional term Vp (S150), and the speed deviation ev is time-integrated, and the integrated value is multiplied by the speed integral gain Kvi to calculate the integral term Vi. (S160).

The proportional value Vp and the integral term Vi are added to calculate the command value Is (S170) and output to the servo amplifier 70 (S180). The servo amplifier 70 drives and controls the servomotor 10 based on the command value Is to move the first arm 8 to the command position Ps.

On the other hand, when the teaching key 66c of the teaching box 66 is pressed by the execution of the process of S110 and the teaching mode is selected, it is determined whether or not there is a jog command (S190). Whether or not it is a jog command is determined by whether or not a plurality of jog command keys 67 of the teaching box 66 are pressed. When the jog command key 67 is pressed, the jog command key 67 is pressed according to the pressed jog command key 67. , A new value is added to or subtracted from the command position Ps to calculate a new command position Ps (S200),
Based on the new command position Ps, the processes from S130 onward are executed, and according to the instruction of the jog command key 66b,
The first arm 8 is swung.

The teaching mode is selected, for example, when teaching the insertion position for inserting the hole 40 of the work 42 held by the chuck 26 into the positioning pin 34, as shown in FIG. Then, the jog command key 66b is operated to move the work 42 gripped by the chuck 26 to the vicinity of the positioning pin 34, and thereafter, when the operator operates the manual operation switch 64, the manual operation switch 6
4 is turned on (S210), and the command position Ps
Is replaced with the current position Pfb detected by the process of S100 (S220). Then, the speed deviation ev is cleared (ev = 0) (S230). The execution of this process works as the control unit 84 in FIG.

Then, the processing from S150 onward is executed,
In S150, since the speed deviation ev is 0, the proportional term Vp becomes 0, and in the subsequent processing, only the integral term Vi is calculated (S160). Since the speed deviation ev is 0, the value of the integral term Vi is held as it is when the manual operation switch 64 is operated.

Therefore, the command value Is becomes equal to the integral term Vi (S170), and the command value Is becomes the servo amplifier 70.
(S180), the rotational force due to the own weight of the hand 16 or each arm 8, 12 at that time balances the rotational force of the servo motor 10, and in that state, each arm 10, 12 or the hand. 16 does not move.

When the operator moves the work 42 while holding the hand 16, the second arm 12, etc., the position P during the movement is moved.
fb is replaced by the commanded position Ps (S220), and by the balance between the driving force of the servomotor 10 and its own weight (S160-
S180), it is possible to move lightly. In the vicinity of the operation of the manual operation switch 64, the positioning force can be easily moved by the balance between the driving force of the servo motor 10 and its own weight, so that the positioning pin 34 can be easily fitted in the hole 40 of the work 42. Alternatively, when the hand 16 and the arms 8 and 12 are desired to be retracted to other positions, they can be moved lightly.

Thereafter, when it is determined that the manual operation switch 64 has been released and turned off (S210), S130.
The following processing is executed. At this time, since the command position Ps is equal to the detected current position Pfb by the processing of S220, the command value Is is equal to the integral term Vi, and this integral term V
Since the servomotor 10 is driven according to the value of i, the first arm 10 does not move rapidly.

When teaching the position where the positioning pin 34 is fitted in the hole 40 of the work 42, the edit key 66 is used.
If e is pressed and it is determined that the edit mode is selected (S1
10), the program is modified by using the current position stored in the command position Ps as the taught position by the processing of S220 (step 240).

When the memory switch 66b is pressed again,
When the memory mode is selected (S110), the process of S120 and thereafter is executed to carry the work 42 to the taught position and insert the hole 40 into the positioning pin 34, so that the positioning pin 34 and the hole 40 are twisted. Or positioning pin 34
Does not bend.

The execution of the processing of S130 to S180 is
It functions as the control unit M3, and the execution of the processes of S210 to S230 functions as the manual operation control unit M5. In addition, S210 to S230 after the manual operation switch 64 is pressed.
It is also possible to execute the processing of (1) not only in the teaching mode but also in another mode, for example, the memory mode.

The present invention is not limited to the embodiments as described above, and can be carried out in various modes without departing from the scope of the present invention.

[0035]

As described above in detail, in the robot controller according to the present invention, when the manual operation switch is operated, the motor is controlled by the integral term when the switch is operated. Therefore, the operator pushes the arm with a light force. The effect that it can be moved is exhibited.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a basic configuration of a robot controller according to the present invention.

FIG. 2 is a schematic configuration diagram of a robot controller according to an embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of an electric system of this embodiment.

FIG. 4 is a block diagram showing a configuration of a control system of this embodiment.

FIG. 5 is a flowchart showing an example of operation control processing performed by the electronic control circuit of the present embodiment.

FIG. 6 is an explanatory diagram illustrating teaching of an insertion position by a conventional robot.

FIG. 7 is an explanatory diagram of a work conveyed by a robot.

[Explanation of symbols]

M1, 4, 10, 14, 18 ... Servo motor M2 ...
Detection means M3 ... Control means M4, 64 ... Manual operation switch M5 ... Manual operation means 1 ... Robot body 6, 2
0, 22, 24 ... Detector 8 ... First arm 12 ... Second arm 34 ...
Positioning pin 40 ... Hole 42 ... Work 50 ...
Electronic control circuit

Claims (1)

[Claims] 1. A detection means for detecting a position and a speed of an arm driven by a servomotor, and a speed deviation according to a speed deviation between the command speed and the detected speed based on a position deviation between the command position and the detected position. A robot having control means for calculating a proportional term, an integral term corresponding to the integral value of the speed deviation, and feedback controlling the servo motor by a command value based on the proportional term and the integral term. The control device includes a manual operation switch, and a manual operation control means for controlling the control means when the manual operation switch is operated to control the servo motor by the integral term when the switch is operated. A robot control device characterized in that