JPH1165632A - Control device - Google Patents

Abstract

(57) [Summary] [Problem] A single control device can support both an analog voltage signal driver and a pulse train signal driver, and can operate a machine by the same operation program regardless of the type of driver used. Control device is provided. In a control device configured to control a plurality of drive axes, a command acquisition unit that receives an operation command to the control device, and a position interpolation unit that calculates a command position of each drive shaft based on the operation command. Unit 3 and a positioning unit that calculates a speed command voltage and a moving amount pulse number based on the command position
4a, 4b, 4c, an analog voltage signal output device 5a, 5b, 5c for calculating an analog voltage signal based on a speed command voltage, and a pulse train signal output device 6a, 6b, 6c for calculating a pulse train signal based on the number of movement amount pulses According to the type of the drivers 8a, 8b, 8c of the actuators 9a, 9b, 9c for driving the drive shaft,
Output switches 7a, 7b, 7c for selectively outputting either an analog voltage signal or a pulse train signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device used for a machine tool or the like, and more particularly to a control device in which an operation command program does not depend on the type of a driver even in a system in which an analog voltage signal driver and a pulse train signal driver are mixed. .

[0002]

2. Description of the Related Art When controlling the operation of a machine tool or the like, a general-purpose CNC device has been widely used as a control device, and recently, a control board for function extension having a positioning / interpolation function in a commercially available personal computer has been used. A so-called personal computer NC equipped with a computer has been used. These N
Servo motors and pulse motors (including stepping motors) are generally used as actuators controlled by the C device. Servo motors and pulse motors are generally used in combination with dedicated drivers (amplifiers) for rotating these motors.

[0003] There are roughly two types of rotation command signals for the driver, one is an analog voltage signal, and the other is a pulse train signal. The driver for the servo motor only needs to correspond to either an analog voltage signal or a pulse train signal, but some of them have both signal processing circuits and can be appropriately switched by a switch circuit. is there. However, as a driver for a servo motor,
When an analog voltage signal driver is used, the position can be directly controlled by the controller, but when a pulse train signal driver is used, the position cannot be directly controlled by the controller.
In this case, since a position control circuit must be provided in the driver, an analog voltage signal driver whose position can be controlled by the control device is generally used as a driver for the servo motor. Further, a driver for a pulse motor or a stepping motor supports only a pulse train signal.

In the case of a servo motor, position feedback is provided to a driver. In the case of a pulse motor or a stepping motor, position feedback is provided to a driver only by receiving an operation command from the driver. Absent. Therefore, when it is necessary to control a plurality of axes synchronously, it is preferable to use a servo motor having position feedback, and to use a pulse motor or a stepping motor limited to an axis that does not need to be synchronized with another axis. It is generally in the form.

Therefore, in view of the above, in general, in a multi-axis control controller having a pulse motor or a stepping motor as one of actuators, an analog voltage signal driver for driving a servo motor and a pulse motor or a stepping motor are driven. The pulse train signal driver is mixed. Problems in a system in which the analog voltage signal driver and the pulse train signal driver coexist are listed below.

[0006] The analog voltage signal driver performs position control on the control device side, but the pulse train signal driver performs position control on the circuit in the driver, so the control device also supports the analog voltage signal driver. And a control device corresponding to the pulse train signal driver. For example, the aforementioned personal computer NC
In the case of, it is necessary to prepare both a control board for function expansion corresponding to the analog voltage signal driver and a control board for function expansion corresponding to the pulse train signal driver. You will be limited by the number of expansion slots.

[0007] Due to the difference in the control devices described in the section, an operation program must also be separately provided for each control device. . Synchronous control such as interpolation control between different axes, that is, between an axis driven by a pulse motor or a stepping motor and an axis driven by a servomotor, due to the difference in the control device described in the section. Cannot be performed. . If the motor to be used is changed from a servo motor to a pulse motor or a stepping motor, or vice versa, at the stage of production or after completion of the machine, the control unit and the operation program Must also be changed.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems of the prior art, and uses a single control device (a control board for function expansion in the case of a personal computer NC). It is another object of the present invention to provide a control device that can support both an analog voltage signal driver and a pulse train signal driver, and that can operate a machine with the same operation program regardless of the type of driver used.

[0009]

In order to achieve the above object, according to the present invention, in a control device for controlling a plurality of drive shafts, a command acquisition unit for receiving an operation command to the control device; Based on the operation command received by the command acquisition unit, a position interpolation unit that calculates a command position for each sampling interval of each drive axis, and a speed command voltage and the number of movement amount pulses based on the command position calculated by the position interpolation unit. A plurality of positioning units corresponding to each of the plurality of drive shafts, which are calculated at each sampling interval, and a plurality of analog voltage signals calculated based on the speed command voltage calculated by the positioning unit. A pulse train signal is calculated based on an analog voltage signal output device corresponding to each of the drive axes and the number of movement amount pulses calculated in the positioning unit. A pulse train signal output device corresponding to each of the plurality of drive shafts, and selectively outputting either an analog voltage signal or a pulse train signal according to the type of the driver of the actuator that drives the drive shaft. An output switch corresponding to each of the plurality of drive shafts is provided.

With the above configuration, the operation command (operation program or manual input) input to the control device is
After the interpolation processing between the drive axes is performed, the drive signal is finally output to each driver as a drive signal corresponding to the type of the actuator that drives the drive axis. Specifically, when the actuator is a servo motor, an analog voltage signal is output. On the other hand, when the actuator is either a pulse motor or a stepping motor, a pulse train signal is output.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a case where the technique of the present invention is applied to a three-dimensional image processing apparatus will be described as one embodiment of the present invention. A three-dimensional image processing apparatus (not shown) is a machine having a general three-dimensional configuration, and includes an XY table movable in a horizontal plane and a Z-axis movable in a vertical direction. A camera for capturing an image is attached to the Z axis, and the camera is focused by operating a Z axis drive motor to move the Z axis up and down. A pulse motor is used as a Z-axis drive motor for operating this camera. This is because, especially when the magnification of the camera is large, the micro-vibration during the stop of the Z-axis causes a large defocus, so it is preferable to use a pulse motor that does not vibrate during the stop as the Z-axis drive motor. It is.

On the other hand, the X-axis drive motor and the Y-axis drive motor for driving the XY table use a servomotor to secure the synchronization between the X-axis and the Y-axis and to improve the response. I have. Here, the synchronism between the X axis and the Y axis means, for example, that when the XY table is actually operated, the X axis drive motor and the Y axis drive motor are simultaneously used to reduce the positioning time. To work,
In this case, it is necessary to perform the interpolation control between the X axis and the Y axis. In order to ensure synchronism between the X axis and the Y axis, it is preferable to use a servo motor that performs position feedback as the X axis drive motor and the Y axis drive motor. As described above, in the three-dimensional image processing apparatus of the present embodiment in which the camera is focused, different types of motors such as a servo motor and a pulse motor are mixed.

Next, FIG. 1 shows the configuration of a control device according to the present embodiment. The control device 1 includes a command acquisition unit 2, a position interpolation unit 3, and positioning units 4a, 4b, 4c for each drive axis.
Analog voltage signal output devices 5a, 5b, 5c, pulse train signal output devices 6a, 6b, 6c, output switching devices 7a, 7b,
7c. The command acquisition unit 2 interprets an operation command for each drive axis, defines a speed and a movement form in a section from the current position (start point position) to the end point position, and outputs this to the position interpolation unit 3. . Here, the form of the operation command includes a pre-programmed operation program and manual input, the speed includes a target speed and an acceleration, and further, in the movement form, linear interpolation, circular interpolation or each interpolation between the drive axes. Specify the axis movement. The position interpolation unit 3
Calculate the movement curve from the current position (start point position) to the end point position, calculate the command position at each sampling interval when moving on this movement curve at the target speed, and drive this command position at each sampling interval. Shaft positioning parts 4a, 4
b, 4c.

Each of the positioning units of each drive shaft, that is, the X-axis positioning unit 4a, the Y-axis positioning unit 4b, and the Z-axis positioning unit 4c are commanded positions output from the position interpolation unit 3 at each sampling interval. A speed command corresponding to a speed control driver based on information of a command position and a current position of the drive motor obtained from a position detector attached to the drive motor so that the position of the drive motor follows the speed command. Calculate the voltage and output it to each analog voltage signal output device 5
a, 5b, and 5c, and the command position output from the position interpolation unit 3 at each sampling interval.
By calculating the difference between the command position at the time of the previous sampling and the command position at the time of the current sampling, the number of movement amount pulses corresponding to the position control driver or the pulse motor driver is calculated. 6
b, 6c.

An analog voltage signal output device for each drive axis, that is, an X-axis analog voltage signal output device 5a, a Y-axis analog voltage signal output device 5b, and a Z-axis analog voltage signal output device 5c are respectively Positioning parts 4a, 4
This is a D / A converter that inputs a digital speed command voltage at each sampling interval output from b and 4c, and outputs this as an analog voltage signal. Further, the pulse train signal output devices of the respective drive axes, that is, the X-axis pulse train signal output device 6a, the Y-axis pulse train signal output device 6b, and the Z-axis pulse train signal output device 6c are respectively provided with respective positioning portions 4a, 4b. , 4c is a pulse oscillator that inputs the number of movement amount pulses at the time of each sampling and outputs this as a pulse train signal within a sampling time.

The output switch of each drive axis, that is, the X-axis output switch 7a, the Y-axis output switch 7b, and the Z-axis output switch 7c are respectively provided with analog voltage signal outputs 5a, 5b. , 5c, and output signals from the pulse train signal output units 6a, 6b, 6c, and selects an output signal according to the type of driver. Specifically, X
Since the axis drive motor and the Y axis drive motor use servo motors, the X-axis output switch 7a and the Y-axis output switch 7b are respectively provided with the X-axis analog voltage signal output unit 5a and the Y-axis output switch 5a. The respective output signals of the analog voltage signal output unit 5b are converted to an analog voltage signal driver
a and the Y-axis analog voltage signal driver 8b are respectively set to output. On the other hand, since the Z-axis drive motor uses a pulse motor, the Z-axis output switch 7c outputs the Z-axis pulse train signal. The output signal of the output device 6c is
It is set to output to the Z-axis pulse train signal driver 8c.

Each of the X-axis analog voltage signal driver 8a and the Y-axis analog voltage signal driver 8b
Based on the analog voltage signal input through each of the axis output switch 7a and the Y-axis output switch 7b,
A drive command is output to each of the X-axis servo motor 9a as the X-axis drive motor and the Y-axis servo motor 9b as the Y-axis drive motor. On the other hand, the Z-axis pulse train signal driver 8c outputs a drive command to the Z-axis pulse motor 9c, which is a Z-axis drive motor, based on the pulse train signal input via the Z-axis output switch 7c.

Each of the X-axis servo motor 9a and the Y-axis servo motor 9b is driven by the X-axis analog voltage signal driver 8a and the Y-axis analog voltage signal driver 8b based on the drive command output from the X-axis analog voltage signal driver 8b. Operate the Y table. On the other hand, the Z-axis pulse motor 9c operates the Z-axis on which the camera is mounted, based on the drive command output from the Z-axis pulse train signal driver 8c. Each of the X-axis servo motor 9a and the Y-axis servo motor 9b is provided with an encoder (position detector) for detecting the current position, and the X-axis analog voltage signal driver 8a
The current position is fed back to each of the analog voltage signal drivers 8b for Y-axis and the analog voltage signal driver 8b for Y-axis, and is also fed back to the positioning unit 4a for X-axis and the positioning unit 4b for Y-axis. On the other hand, an external position detector 10 is provided in addition to the Z-axis pulse motor 9c, and the current position is fed back to the Z-axis positioning unit 4c.

In the configuration of the present embodiment described above, since the command acquisition unit 2 is common to all drive axes, the control unit 1
Are the same regardless of the type of driver. Further, the position interpolation unit 3
Is common to all the drive axes, so that interpolation control between the X and Y axes driven by the servomotor and the Z axis driven by the pulse motor is also possible. As described above, according to the present embodiment, it is possible to configure a system with a single control device without separately providing a control device for different types of drivers such as an analog voltage signal driver and a pulse train signal driver.

Further, when the drive shaft motor and the driver are changed, for example, when the pulse motor and the pulse train signal driver on the Z axis are changed to a servo motor and an analog voltage signal driver, respectively, This can be dealt with simply by switching the output switch 7c from the pulse train signal output unit 6c side to the analog voltage signal output unit 5c side, and there is no need to change the control unit itself or the operation program (operation command). Further, since the configuration of the control device 1 can be arranged on one board, it can be easily mounted as a control board for expanding the functions of a commercially available general-purpose personal computer.

In the above embodiment, the output switches 7a, 7b, 7c are connected to the analog voltage signal output
a, 5b, 5c, and pulse train signal output devices 6a, 6b,
Although it is arranged as the next process of 6c, this is replaced,
As next steps of the output switches 7a, 7b, 7c, the analog voltage signal output units 5a, 5b, 5c and the pulse train signal output units 6a, 6b, 6c may be arranged.
Further, in the above embodiment, the number of drive shafts is three, but the number of drive shafts may be two or four or more, and the invention is easily applicable within the technical scope of the present invention. For example, a rotary table (C axis) is provided on the XY table of the above-described embodiment, and the present invention can be easily applied to a machine having a total of four drive axes of X, Y, C, and Z axes. . Further, in the above embodiment, the case where the pulse motor is applied as the actuator driven by the pulse train signal driver has been described, but the same applies to the case where the stepping motor is applied as the actuator.

[0022]

According to the present invention, in a control device for controlling a plurality of drive shafts, a command acquisition section for receiving an operation command for the control device, and a command position of each drive shaft based on the operation command. A position interpolating unit to calculate, a positioning unit to calculate the speed command voltage and the number of movement pulses based on the command position; an analog voltage signal output unit to calculate an analog voltage signal based on the speed command voltage; A pulse train signal output device for calculating a pulse train signal;
An output switch that selectively outputs either an analog voltage signal or a pulse train signal in accordance with the type of the driver of the actuator that drives the drive shaft, so that the operation command input to the control device is provided. Is interpolated and finally output to each driver as a drive signal corresponding to the type of driver of the actuator that drives the drive shaft.

Therefore, the present invention has the following unique effects over the prior art. . The operation command input to the control device is interpolated and finally output to each driver as a signal corresponding to the type of the driver of the actuator that drives the drive shaft. It is no longer necessary to provide a separate control device according to the type of driver and the type of driver. As a result, in the case of the personal computer NC, it is not necessary to provide a plurality of function expansion control boards according to the types of the motor and the driver, and the control device can be constituted by one control board.

[0024] Since there is one control device irrespective of the type of motor and driver, it is not necessary to provide an operation program separately for each control device, and the operation program can be created without considering the type of motor or driver to be used. It can be done. . Since the position interpolation unit in the control device is shared by all the drive axes, synchronous control such as interpolation control between the drive axes can be easily performed. . Since the control device is no longer affected by the type of motor or driver, if the motor used is changed from a servo motor to a pulse motor or stepping motor, or vice versa, at the stage of machine production or after completion But there is no need to change the operating program.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a control device according to an embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1 control device 2 command acquisition unit 3 position interpolation unit 4a positioning unit (X-axis positioning unit) 4b positioning unit (Y-axis positioning unit) 4c positioning unit (Z-axis positioning unit) 5a analog voltage signal output unit (X-axis) 5b Analog voltage signal output device (Y-axis analog voltage signal output device) 5c Analog voltage signal output device (Z-axis analog voltage signal output device) 6a Pulse train signal output device (X-axis pulse train signal) Output device 6b Pulse train signal output device (Y-axis pulse train signal output device) 6c Pulse train signal output device (Z-axis pulse train signal output device) 7a Output switching device (X-axis output switching device) 7b Output switching device (Y-axis) 7c Output switcher (Z-axis output switcher) 8a Driver (X-axis analog voltage signal driver) 8b Driver (Y-axis analog switch) Grayed voltage signal driver) 8c driver (Z-axis pulse train signal driver) 9a actuator (servomotor X-axis) 9b servomotor actuator (Y-axis) 9c actuators (pulse motor for Z-axis) 10 Position detector

Claims (2)

[Claims] 1. A control device configured to control a plurality of drive axes, a command acquisition unit for receiving an operation command for the control device, and a command acquisition unit that receives the operation command for each drive shaft based on the operation command received by the command acquisition unit. A position interpolator for calculating a command position for each sampling interval; and a plurality of speed command voltages and the number of movement pulses based on the command position calculated by the position interpolator for each sampling interval. A positioning section corresponding to each of the plurality of drive axes; and an analog voltage corresponding to each of the plurality of drive axes, wherein an analog voltage signal is calculated based on the speed command voltage calculated in the positioning section. A signal output unit; and the plurality of drive units configured to calculate a pulse train signal based on the number of movement amount pulses calculated by the positioning unit. A pulse train signal output device corresponding to each of the axes, and corresponding to a type of a driver of an actuator that drives the drive shaft, wherein the analog voltage signal or the pulse train signal is selectively output. An output switching device corresponding to each of the plurality of drive shafts. 2. The output switching device outputs the analog voltage signal when the actuator is a servo motor, and outputs the pulse train signal when the actuator is a pulse motor or a stepping motor. The control device according to claim 1, wherein: