JPH01207624A - System for mastering absolute pulse coder system - Google Patents

Abstract

PURPOSE:To perform mastering operation automatically by making a return to an incremental origin and storing the value of the counter of an absolute pulse coder (APC) at the time of the completion of the origin return as a reference position. CONSTITUTION:Servo amplifiers 21 for respective shafts are connected to a shaft controller 16 coupled with a CPU 11 and perform power amplification to drive respective servomotors 20. An absolute pulse encoder (APC) 22 is fitted to the motor shaft of each servomotor 20 and the APC 22 is provided with an incremental pulse coder which generates pulses by the rotation of the servomotors 20 and a counter 22a which counts output pulses of the pulse encoder. The counted value S2 of the counter 22a is inputted to a controller 10 through the shaft controller 16. Then the incremental origin return is made and the value of the counter 22a of the APC 22 at the time of the completion of the origin return is stored as the reference position in a data memory 13 consisting of an RAM backed up by the battery 14 of the controller 10.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a mastering method for an absolute pulse coder (hereinafter referred to as APC) having a counter backed up by a battery, which is applied to industrial robots, NG machine tools, etc. .

The conventional technology △PC system includes an incremental pulse coder and a counter backed up by a battery, the output pulses from the pulse coder are counted by the counter, and the APC is installed based on the counted value of the counter. It detects the absolute position of @ (a moving object such as a machine).

In this APC system, the counter counts and updates the output pulses from the incremental pulse coder, so the value of the counter corresponding to a specific position of the axis on which the APC is installed, that is, the reference position, is stored in the control device. It is stored in a battery-backed memory, and based on the counter value at this reference position, the current position is determined according to the formula shown below.

Current position δ=K·(Current counter value−Counter value at reference position) 10 Reference position Note that in the above equation, K is a constant determined by the reduction ratio of the mechanical part, etc.

As mentioned above, in this APC system, it is necessary to store the counter value at the reference position.
It is necessary to perform an operation to store the value of the PC counter in a battery backup memory in a control device of a robot, an NG machine tool, etc., that is, a mask ring. Normally, this mastering involves installing a calibration jig, manually positioning the industrial robot or NC machine tool accurately at the position specified by the calibration jig, and controlling the value of the APC counter at the end of this positioning. A method is adopted in which the information is stored in a battery backup memory within the W device.

Problems to be Solved by the Invention The above-mentioned mastering is useful not only when first determining the coordinate system for industrial robots and NC machine tools, but also when replacing major mechanical parts such as motors, and when using battery backup power sources. However, the mastering operation, which involves installing a calibration jig and manually positioning all the axes of the machine to the positions specified by the jig, is time-consuming and troublesome, and recovery is troublesome. The disadvantage is that it requires

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a mastering method for an APC system that allows automatic mastering.

Means for Solving the Problems In order to solve the above problems, the method of the present invention performs incremental home return, and when the home return is completed, the APC
The value of the counter is stored in the battery backup memory of the controller 11 as a reference position.

By performing incremental home return, the machine is operated according to a certain sequence, and the dog and limit switch provided in the mechanical part of the machine cause the limit switch to step on the dog, and the signal from the limit switch is output immediately. The motor (machine) is stopped at the first motor rotation signal position from the falling edge of . The position of the motor (machine) at this time is a specific position set by the dog, that is, the reference position, and by storing the current APC counter value in the battery backup memory, the machine reference position d The APC counter value at is stored in the battery backup memory, and mastering is completed.

Embodiment FIG. 2 is a block diagram of a main part of an APC system for a machine such as an industrial robot or an NC machine tool in which the present invention is implemented.

In the figure, 10 is a control device such as a machine NG device, and a central processing unit (hereinafter referred to as CPLI) 11 includes a memory 12 . Backed up by battery 14,
15° axis controller 16. Manual data input device with data processing and CRT display device consisting of RAM. Input/output circuit 17
are connected by a bus 18.

The memory 12 stores a control program, and the data memory 13 stores teaching data if the machine is a robot, and NG programs if the machine is an NC machine tool. The axis controller 16 is composed of a software servo including a servo system position control circuit for controlling a servo motor 20 that drives an axis that is a movable part of the machine, and a voltage control circuit for a servo amplifier 21.

A servo amplifier 21 for each axis is connected to the axis controller 16, and the servo amplifier 21 amplifies power to drive each servo motor 20. Note that FIG. 2 shows only one axis, and only one servo amplifier, servo motor, etc. A ΔPC 22 is attached to the motor shaft of the servo motor 20, and the APC 22 has an incremental pulse coder that generates pulses by the rotation of the servo motor 20, and a counter 22a that counts the output pulses of the pulse coder (<5). .The counter 2
The count value S2 of 2a is sent to the control device 10 via the axis controller 16.
has been entered. Further, a one-rotation signal S1 generated from the ΔPC every time the servo motor 20 makes one rotation is also input to the control device 10 via the axis controller 16.

In connection with the present invention, the input/output circuit 17 receives a signal generated when the limit switch depresses the dog by a switch for the dog and limit 1 provided in the machine to detect the reference position. There is.

The above configuration is similar to the APC system of conventional industrial robots and NC machine tools, and the difference from the conventional APC system is that the machine is equipped with a dog and a limit switch to detect the reference position. The only difference is that the signal from the switch is input to the input/output circuit, and the one-rotation signal S1 is input to the control device 10.

In the above configuration, the CPU 11 performs the processing shown in FIG. 1 every time the power is turned on to a machine employing this APC system 1'.

First, the CPU 11 determines whether the mask ring end flag F provided in the data memory 13 is set (step S1), and if it is not set, performs incremental origin return processing (step S2). That is, the servo motor 20 of each axis is controlled by the axis controller 16 .
It is driven via a servo amplifier 21. Servo motor 20
When the APC 22 rotates, output pulses are generated from the incremental pulse loader of the APC 22, and the counter 22a counts these pulses. On the other hand, when the limit switch provided in the machine steps on the dog and outputs a signal, the falling edge of the signal is detected via the input/output circuit 17, and the CPU 11 detects the first one-rotation signal S1 generated thereafter (normal limit When the servo motor rotates half a revolution from the fall of the signal from the switch, the dog etc. are adjusted so that a one revolution signal is output), and the rotation of the servo motor is stopped. After performing this incremental home return process on all axes, the count value S2 of the counter 22a of the APC 22 for each axis is stored in the data memory 13 as mastering data (step 83). Then, the mastering completion flag F provided in the data memory 13 is set (F=1) (step 8
4). Then, evaluate the current position of each axis in step S5.
), the power-on processing ends.

In this way, after the mastering end flag F1 is set, when the power is turned off and then turned on again, since the mastering end flag F1 has already been set, step S1
The process then proceeds to step S5, where the current position is calculated and the process proceeds to the next process without performing mastering processing such as incremental return to origin.

As described above, since the first process is automatically performed every time the machine is powered on, there is an accident such as the battery 14 backing up the data memory 13 running out, and the data stored in the data memory 13 is APC2 at the reference position
Even if the value of the counter 22a of No. 2, that is, the mask ring data, disappears, mastering is automatically performed by inputting the Tie, so there is no need to perform conventional mastering, which is troublesome and time-consuming.

In the above embodiment, when the power is turned on, it is determined whether or not mastering has been completed, and if mastering has not been completed, the mastering process is automatically performed.
It is also possible to input a mastering command from the manual data input fI device 5 with a T-display device, etc., and have the processes from step 82 onward in FIG. 1 be performed automatically.

Effects of the Invention The mastering method of the present invention does not require a calibration jig, etc., and mastering is automatically performed using incremental home return based on mastering commands. Therefore, mastering does not take much time and effort, and it reduces the risk of accidents. Recovery becomes easier.

[Brief explanation of the drawing]

FIG. 1 is a flowchart of an embodiment of the present invention, and FIG. 2 is a 10-step diagram of essential parts of an APC (absolute pulse coder) system implementing the embodiment. 10...Control device, 11...Central processing unit 1 (CP
U), 13... data memory, 16... axis controller,
20... Servo motor, 22... Absolute pulse coder (APC). Figure 1 Figure 2

Claims (1)

[Claims] A mastering method for an absolute pulse coder system that performs incremental home return and stores the value of the absolute pulse coder's counter at the time the home return is completed as the reference position in the battery backup memory.