JPH0991016A - Numerical controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a position error at an optional place and optional time other than reference point restoration. SOLUTION: An integration counter 16 integrates the interpolation pulses of moving command data 11 and the interpolation pulses of correction data 12. A machine coordinate counter 17 integrates only the interpolation pulses of the data 11. An absolute position detecting counter 18a counts up an one- rotation signal to be an absolute position detection value from a servo motor 72. A machine side position error detecting means 19 compares a value obtained by adding the integration value of the counter 16 and the initial value of the counter 18a with the count value of the counter 18a. A CNC (computerized numerical controller) side position error detecting means 20 compares the output of a machine coordinate data generating part 13 with the integration value of the counter 17. When a data difference is not included in an allowable range as the result of comparison, an alarm signal is outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a numerical control device, and more particularly to a numerical control device that performs position error detection control.

[0002]

2. Description of the Related Art In a numerical control device (CNC), it is checked whether or not the absolute position measured by an absolute position detector and the integrated value of movement commands instructed by an NC program correspond to each other. This is also done when returning to the reference point.

That is, an absolute position detector is attached to each axis of the numerical controller. Then, the absolute position detection counter in the absolute position detector counts the current position of the machine to detect the absolute position. On the other hand, the interpolation pulse of the movement command data in the NC program is counted by the reference counter in the device. Then, the position error is detected by comparing the count value from the absolute position detection counter and the count value from the reference counter at the reference point.

[0004]

However, the position error detection performed at the time of returning the reference point is limited to the reference point at a specific place and at a specific time. Therefore, the position error detection is not performed at any other place or time. Didn't.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a numerical controller capable of detecting a position error at an arbitrary place and time.

[0006]

In order to solve the above problems, the present invention integrates an interpolation pulse of movement command data and an interpolation pulse of correction data for a servomotor in a numerical controller for position error detection control. A total counter, an absolute position detection counter for counting the absolute position detection value for the servo motor, a value obtained by adding the total value of the total counter and the initial value of the absolute position detection counter, and the count of the absolute position detection counter If the difference between these data is not within the allowable range by comparing the values, the machine side position error detection means that outputs an alarm signal and the machine coordinate counter that integrates the interpolation pulse of the movement command data for the servo motor , Machine coordinate data set by parameters, integrated value of the machine coordinate counter and the machine coordinate data By comparing the difference in these data may not be within the allowable range, a numerical controller and having a numerical control-side position error detecting means for outputting an alarm signal is provided.

Here, the integration counter integrates the interpolation pulse of the movement command data and the interpolation pulse of the correction data. The machine coordinate counter integrates only interpolation pulses of movement command data. The absolute position detector is attached to the servo motor, and an absolute position detection counter inside the servo motor counts one rotation signal which is an absolute position detection value of the servo motor. The machine side position error detection means compares the value obtained by adding the integrated value from the integration counter and the initial value of the absolute position detection counter with the count value from the absolute position detection counter, and the data difference is not within the allowable range. In that case, an alarm signal is output. The CNC side position error detecting means compares the integrated value from the machine coordinate counter with the machine coordinate data and outputs an alarm signal if the data difference is not within the allowable range.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a numerical control device (C
It is a conceptual diagram which shows the principal part in NC. CNC is
The movement command data 11 and the correction data 12, the movement command data interpolating means 14 and the correction data interpolating means 15 for converting these data into interpolation pulses respectively, the machine coordinate data 13 set by the parameters, and the interpolation pulse to the speed instruction. An axis control circuit 52 that converts the signal into a signal and outputs the signal to the servo amplifier 62, and an integration counter 16 that integrates the interpolation pulse
A mechanical coordinate counter 17 that integrates only the interpolation pulses of the movement command data 11, an absolute position detector 18 attached to the servomotor 72, an absolute position detection counter 18a included in the absolute position detector 18, Machine side position error detection means 19 for comparing the count value of the absolute position detection counter 18a and the integration value of the integration counter 16, and CNC side position error detection means 20 for comparing the integration value of the machine coordinate counter 17 and the machine coordinate data. Composed of and.

The movement command data 11 is a movement command value for the servo motor 72. This is instructed by the motion command from the CNC. The correction data 12 are correction values such as backlash correction, pitch error correction, and straightness correction. The machine coordinate data 13 is set in advance as a parameter for each command for detecting a position error in the NC program.

The movement command data interpolation means 14 converts the movement command data 11 into interpolation pulses. The correction data interpolating means 15 converts the correction data 12 into interpolation pulses. The axis control circuit 52 receives these interpolation pulses, converts them into speed command signals, and outputs them to the servo amplifier 62.

The integration counter 16 integrates the interpolation pulse of the movement command data 11 and the interpolation pulse of the correction data 12. The machine coordinate counter 17 integrates only the interpolation pulse of the movement command data 11. The absolute position detector 18 is attached to the servomotor 72 and backed up by a battery. The absolute position detection counter 18a provided therein counts one rotation signal which is the absolute position detection value of the servo motor 72.

The machine side position error detecting means 19 compares the value obtained by adding the integrated value from the integrating counter 16 and the initial value of the absolute position detecting counter after the power is turned on with the count value from the absolute position detecting counter 18a. , If the data difference is not within the allowable range, an alarm signal is output. Therefore, when the alarm signal is output, it can be determined that the absolute position detector 18 is abnormal, the integrating method of the integrating counter 16 is abnormal, or the like.

The CNC side position error detecting means 20 compares the machine coordinate data 13 with the integrated value from the machine coordinate counter 17, and outputs an alarm signal if the data difference is not within the allowable range. The machine coordinate data 13 is a value in which the integrated value of the machine coordinate counter 17 is set in advance in the form of a parameter for each command for position error detection. Therefore, when the alarm signal is output, it can be determined that there is an abnormality in the movement command data 11 or a parameter setting error in the machine coordinate data 13.

Next, the process of the position error detection according to the present invention will be described in detail using an NC program. FIG. 2 shows an NC program 10 for position error detection. The command “G28 G91 X0 Y0Z0;” of the sequence number N001 of the program number O100 is a reference point return command, and the origin is positioned as a reference point in incremental coordinates. Sequence number N002 command "G00 G90 Z-100. Y2
00. X-200. “;” Is a positioning command, which is an absolute coordinate value and Z = −100.0, Y = 20 for each axis.
0.0 and X = -200.0, respectively, and it is positioned. Sequence number N003 command "T01
; Is a tool change command and has a sequence number N00.
Tool exchange is performed with the coordinate values positioned in 2. Sequence number N004 command "S1000 M03
; Is the rotation command of the spindle, and is 100 clockwise per minute.
Rotate 0 times. Sequence number N005 command "G01
X200. F1000; ”and the sequence number N
006 “Y300 .;” is a linear interpolation command, and X =
200.0 is linearly interpolated at a cutting feed speed of 1000 mm / min, and then Y = 300.0 is linearly interpolated at the same speed. Therefore, the position up to here is X by these commands.
= 200.0 Y = 300.0 Z = -100.0. This coordinate value corresponds to the integrated value counted by the machine coordinate counter.

Sequence number N007 "G25.1
"P1;" is a command for detecting a position error. G25.
When one code is commanded, the machine side position error detection and the CNC side position error detection are performed. In the machine side position error detection, a value obtained by adding the integrated value of the integration counter and the initial value of the absolute position detection counter after the power is turned on is compared with the count value of the absolute position detection counter. Furthermore, in the position error detection on the CNC side, the integrated value of the machine coordinate counter and the machine coordinate data 1
Coordinate value P1 of 3 (X = 200.0, Y = 300.0, Z
= -100.0) is compared. When the difference between these data exceeds the allowable range, an alarm signal is output. In this figure, the integrated value of the machine coordinate counter and the coordinate value P
It turns out that it matches 1 correctly.

The command "G90" of the sequence number N020
X500.0 Y600.0; ", the position coordinates of absolute coordinate values X = 500.0 and Y = 600.0 are set. Therefore, by these operations, the position up to this point is X = 500.0 Y = 600.0 Z = -100.
It is 0, and this value corresponds to the integrated value of the machine coordinate counter.

Sequence number N021 "G25.1
"P2;" is also a command for performing absolute position detection. G25.
When one code is commanded, the machine side position error detection and the CNC side position error detection are performed. The machine side position error detection is similar to the above description. In the position error detection on the CNC side, the integrated value of the machine coordinate counter and the coordinate value P2 of the machine coordinate data 13
(X = 500.0, Y = 600.0, Z = -100.
0) is compared. If the data difference exceeds the allowable range, an alarm signal is output. In this figure, it can be seen that the integrated value of the machine coordinate counter and the coordinate value P2 are correctly matched.

FIG. 3 is a diagram showing a schematic configuration of hardware to which the present invention is applied. Numerical control unit (CNC) 30
Is composed of a main processor section (MAIN CPU) 40 and an expansion slot section 50. Processor (CPU)
41 is a read-only storage device (RO
M) Read out the system program stored in 42.
The entire operation of the CNC 30 is controlled according to this system program. Random access memory (RAM) 43
Stores temporary calculation data, display data, and the like.
A nonvolatile random access memory (RAM) 44 is backed up by a battery 45, and stores a tool measurement value, a tool correction amount, an NC program, parameters, etc., which are data to be retained even after the power is turned off. The video RAM 46 stores image data to be displayed on the display device.
This image data is transmitted to the display device (CRT) 47 and displayed. The keyboard (KEY) 48 includes operation keys and function keys used for data input.

A programmable machine cot roller (PMC) 51 controls the machine side with a sequence program created in a ladder format. That is, the sequence program is converted into a necessary signal on the machine side according to the M function, S function and T function created by the NC program.
Then, the output is made from the I / O unit 61 to the machine side. Further, the I / O unit 61 is connected to a strong electric panel or an operation panel 71.

The axis control circuits 52 and 53 receive a movement command interpolated and distributed to each axis from the CPU 41, convert it into a speed command signal, and output it to the servo amplifiers 62 and 63. The servo amplifiers 62 and 63 amplify the speed command signal and drive the servo motors 72 and 73 of each axis. Similarly, the spindle control circuit 54 also receives a movement command interpolated and distributed to the spindle from the CPU 41, converts the movement command into a speed command signal, and outputs the speed command signal to the servo amplifier 64. The servo amplifier 64 amplifies the speed command signal and drives the servo motor 74 of the main shaft.

The spindle control circuit 55 outputs a spindle speed signal to a spindle amplifier 65 in response to a spindle rotation command and a spindle orientation command. The spindle amplifier 65 receives the spindle speed signal and rotates the spindle motor 75 at the commanded rotation speed. Further, the spindle is positioned at a predetermined position according to the orientation command.

The interface (INT) 56 is an interface for an external device, and is connected to an external device (TR) 66 such as a paper tape reader or a paper tape puncher.
Since the machine side position error detection and the CNC position error detection are provided as described above, the position comparison check can be performed at any time by the program command. Further, in the above description, the case of the numerical control device including both the machine side position error detection and the CNC side position error detection has been described, but a numerical control device having only one of them may be used.

[0023]

As described above, according to the present invention, the numerical control device is provided with the function of performing the machine side position error detection and the CNC side position error detection. As a result, the position error detection performed at the time of returning to the reference point can be performed at other places and times, so that the position error can be detected early and erroneous cutting can be minimized.

[Brief description of drawings]

FIG. 1 is a principle diagram showing an outline of a numerical controller according to the present invention.

FIG. 2 is an example of an NC program that performs position error detection.

FIG. 3 is a diagram showing a schematic configuration of hardware to which the present invention is applied.

[Explanation of symbols]

 11 Movement Command Data 12 Correction Data 13 Machine Coordinate Data 14 Movement Command Data Interpolation Means 15 Correction Data Interpolation Means 16 Integration Counter 17 Machine Coordinate Counter 18 Absolute Position Detector 18a Absolute Position Detection Counter 19 Machine Side Position Error Detection Means 20 CNC Side Position Error detection means 52 Axis control circuit 62 Servo amplifier 72 Servo motor

Claims (3)

[Claims] 1. A numerical controller for performing position error detection control, wherein an integration counter for integrating an interpolation pulse of movement command data and an interpolation pulse of correction data for a servo motor, and an absolute position detection value for the servo motor are counted. An absolute position detection counter, a value obtained by adding the integrated value of the integration counter and the initial value of the absolute position detection counter, and the count value of the absolute position detection counter are compared, and the difference between these data is within an allowable range. And a machine side position error detecting means for outputting an alarm signal if not present in the numerical control device. 2. In a numerical controller for performing position error detection control, a machine coordinate counter that integrates interpolation pulses of movement command data for a servo motor, machine coordinate data set by a parameter, and an integrated value of the machine coordinate counter. And the machine coordinate data are compared with each other, and if the difference between these data is not within the allowable range, the numerical control side position error detecting means for outputting an alarm signal is provided. 3. A numerical controller for performing position error detection control, an integration counter for integrating an interpolation pulse of movement command data and an interpolation pulse of correction data for a servo motor, and an absolute position detection value for the servo motor. An absolute position detection counter, a value obtained by adding the integrated value of the integration counter and the initial value of the absolute position detection counter, and the count value of the absolute position detection counter are compared, and the difference between these data is within an allowable range. If not, the machine side position error detection means that outputs an alarm signal, the machine coordinate counter that integrates the interpolation pulse of the movement command data for the servo motor, the machine coordinate data set by the parameter, and the machine coordinate counter Of the machine coordinate data and the difference between these data is within the allowable range. And a numerical control side position error detecting means for outputting an alarm signal.