JPH0553622A - Multi-axis controller for servo motor - Google Patents

Abstract

PURPOSE:To obtain a multi-axis controller for a servo controller which is capable of proper control in accordance with the basic performance of the rated torque, the rated rotational frequency, etc., when plural types of servo motors of different rated outputs are driven with mutual switching. CONSTITUTION:A control circuit 24 of a servo motor driving system is provided with a DSP 30, an inverter selection circuit 32, a sensor selection circuit 38, and a control information storage circuit 42. The DSP 30 reads the control information out of the circuit 42 with input of the servo motor selection information and energizes an inverter selection circuit 32 for selection of an inverter circuit 16a. At the same time, the DSP 30 energizes a sensor selection circuit 38 to select a current sensor 20 and a position sensor 22a of a servo motor. Thus the DSP 30 can apply the optimum control to a selected servo motor based on the optimum control information, the current sensor information, and the position sensor information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a servomotor multi-axis controller capable of appropriately controlling a plurality of servomotors.

[0002]

2. Description of the Related Art In recent years, industrial robots such as welding robots and assembly robots have been widely used in the industrial world. However, these industrial robots have high responsiveness for driving axes of manipulators and Servo motors with high positioning accuracy are widely used.

A servo motor control device including a digital signal processor (hereinafter, referred to as DSP) is used to control the plurality of servo motors. In this servo motor control device, a plurality of servo motors can be controlled by a single DSP.

[0004]

However, in the servo motor control device according to the above-mentioned prior art, since the preset control information is for a servo motor having a single rated output, a plurality of different rated outputs are provided. There is an inconvenience that the servo motor cannot be controlled.

Further, even if the servomotors have the same rated output, since the preset feedback gain is constant, proper control cannot be performed when the loads are largely different.

The present invention has been made in order to solve such a conventional problem, and it is possible to properly control a plurality of servomotors having different rated outputs, and to load a plurality of servomotors. It is an object of the present invention to provide a multi-axis controller for a servo motor that can be appropriately controlled according to the above.

[0007]

In order to achieve the above object, the present invention provides a sensor selection circuit for selecting a desired sensor from a current sensor and a position sensor arranged in each of a plurality of servomotors. An inverter selection circuit for selecting a desired inverter circuit from the inverter circuits arranged in each of the plurality of servo motors, a control information storage circuit for storing control information of the respective servo motors, and a servo supplied from the outside. Based on the motor selection information, the sensor selection circuit is energized to select the desired sensor, the inverter selection circuit is energized to select the desired inverter circuit, and the desired control information is stored from the control information storage circuit. And a control circuit for reading and controlling the servo motor.

[0008]

In the servomotor multi-axis controller according to the present invention, the control circuit reads the desired control information from the control information storage circuit based on the servo motor selection information output from the teaching device, and also controls the sensor selection circuit. Energize to select the sensor and energize the inverter selection circuit to select the inverter circuit.

Therefore, the control circuit can control the servomotor connected to the proper inverter circuit according to the proper control information and the sensor information.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a multi-axis controller for a servo motor according to the present invention will be described in detail below with reference to the accompanying drawings with reference to preferred embodiments.

FIG. 1 is a block diagram showing the configuration of a servo motor drive system for implementing a multi-axis controller for a servo motor according to the present invention.

In the figure, reference numeral 10 indicates a servo motor drive system. The servomotor drive system 10 includes a converter circuit 14 that converts an AC power supply 12 into a direct current, and inverter circuits 16a to 16a that convert the direct current into a high frequency alternating current.
6c, current sensors 20a to 20c composed of a toroidal coil or the like for detecting a current value supplied to the servomotors 18a to 18c, and the servomotors 18a to 18
Position sensors 22a to 22c that are absolute type encoders that detect the amount of rotation of c.

Further, the servo motor drive system 10 includes the current sensors 20a to 20c and the position sensor 22.
The sensor information of a to 22c is read and the inverter circuits 16a to 16c are provided with servo motors 18a to 18c.
Control circuit 24 for deriving a signal for controlling
And a teaching box 26 for supplying control information including rotational speeds and displacement positions of the servo motors 18a to 18c and selection information for selecting the servo motors 18a to 18c to be driven to the control circuit 24.
Composed of and.

FIG. 2 shows a block diagram of the control circuit 24.

The control circuit 24 includes an I / O 28,
A DSP 30 as a control calculation unit, an inverter selection circuit 32 that selects the inverter circuits 16a to 16c under the control of the DSP 30, and an RO that stores a control program.
RAM for temporarily storing M34 and data under control
And 36.

Further, the control circuit 24 includes the current sensors 20a to 20c and the position sensors 22a to 22c.
The sensor selection circuit 38 includes an analog multiplexer that selects a desired sensor output from a sensor such as 2c, and an A / D conversion circuit 40 that converts the value output from the sensor selection circuit 38 into a digital value. A control information storage circuit 42 that stores optimum control information of the servo motors 18a to 18c having different outputs as a look-up table (hereinafter referred to as LUT).

In this case, the control information storage circuit 42 stores the feedback gain information of the servomotors 18a to 18c and the control information including the abnormality detection level such as the overcurrent abnormality and the overload abnormality.

By the servo motor drive system 10 configured as described above, the servo motor 18a is supplied in accordance with the information supplied from the teaching box 26 for selecting the servo motor 18a having a predetermined rated output, for example.
The function and effect of appropriately controlling the above will be described in detail below with reference to FIGS. 1 to 3.

An external device (not shown) stores feedback gain information and control information including abnormality detection levels such as overcurrent abnormality and overload abnormality in the control information storage circuit 42 in advance as an LUT.

The selection information for selecting the servo motor 18a input using the teaching box 26 is I / O2.
The data is read by the DSP 30 via 8 (step S3
1), D based on the information indicating the servo motor 18a
The SP 30 reads the LUT indicating the control information of the servo motor 18a stored in advance in the control information storage circuit 42 (step S32), and further outputs a control signal to the sensor selection circuit 38 including an analog multiplexer, The current sensor 20a and the position sensor 22a of the servomotor 18a are selected, and the selection signal S for selecting the inverter circuit 16a is output to the inverter selection circuit 32 (step S33).

The inverter circuit 16a selected by the inverter selection circuit 32 by the selection signal S is a DSP.
The servomotor 18a can be driven based on the drive signal D output from 30, and the other inverter circuits 16b and 16c cannot enter the drive signal D, which is a so-called input prohibited state.

Next, the DSP 30 reads the drive sequence information of the servo motor 18a, which is input from the teaching box 26 and is stored in the RAM 36, and is composed of a plurality of position information and the like (step S34). Output to the servo motor 18 only by the inverter circuit 16a selected in step S33 reads the drive signal D.
Drive a (step S35).

In step S35, the servo motor 18
When a is driven, the current sensor 20a reads the drive current Ia output from the inverter circuit 16a, and the read drive current Ia is input to the sensor selection circuit 38.

Since the sensor selection circuit 38 selects the current sensor 20a in step S33, the drive current Ia detected by the current sensor 20a is A / D conversion circuit 40.
Is input to and converted into a digital value. This drive current I
The value a is read by the DSP 30 and used for control calculation based on the feedback gain information read from the control information storage circuit 42.

On the other hand, the rotation amount information Pa of the servo motor 18a detected by the position sensor 22a provided on the servo motor 18a is the same as the current sensor information, and the sensor selection circuit 3
8 and the A / D conversion circuit 40 and read by the DSP 30, and feedback control of the servo motor 18a is performed.

When all the driving sequence information read from the RAM 36 is completed (step S36), the DSP 30
Stops the output of the selection signal S to put the inverter circuits 16a to 16c into the input prohibited state (step S37).

By repeating the above steps S31 to S37, the servomotors 18a to 1 having different rated outputs are provided.
8c is driven under the control of the DSP 30.

As described above, according to this embodiment, the servo motor 1 output from the teaching box 26 is output.
Based on the information for selecting 8a, the DSP 30 reads the control information of the servo motor 18a stored in advance from the control information storage circuit 42, and the inverter selection circuit 32.
To select the inverter circuit 16a that drives the selected servomotor 18a by controlling the
8 to select the current sensor 20a and the position sensor 22a arranged on the servo motor 18a, the servo motors having different rated outputs can be properly operated to maintain basic performance such as rated torque and rated speed. It can be controlled by the state.

Further, D is determined by the value of the current for driving the servo motor 18a detected by the current sensor 20a.
By controlling the feedback gain preset in the control information storage circuit 42, the SP 30 can perform appropriate current control even when the servo motors have the same rated output and the loads are significantly different. Becomes

Further, since a plurality of servomotors can be controlled by the single control circuit 24 and the converter circuit 14, the servomotor drive system 10 can be miniaturized.

[0031]

In the servo motor multi-axis control controller according to the present invention, the control circuit can properly control a plurality of types of servo motors connected to a predetermined inverter circuit according to appropriate control information and sensor information. It is possible to properly control a plurality of servo motors having different loads according to the loads.

Therefore, it is possible to control a plurality of servo motors having different rated outputs and a plurality of servo motors having different loads with a single controller, so that the servo motor control system can be miniaturized. At the same time, there is an effect that the production cost is reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a servo motor drive system that implements a multi-axis controller for a servo motor according to the present invention.

FIG. 2 is a block diagram showing a configuration of a control circuit in the servo motor drive system shown in FIG.

FIG. 3 is a control flowchart for controlling a servo motor in the embodiment shown in FIG.

[Explanation of symbols]

 10 ... Servo motor drive system 14 ... Converter circuit 16a-16c ... Inverter circuit 18a-18c ... Servo motor 20a-20c ... Current sensor 22a-22c ... Position sensor 24 ... Control circuit 30 ... DSP 32 ... Inverter selection circuit 38 ... Sensor selection Circuit 42 ... Control information storage circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeo Kobayashi 1-10-1 Shin-Sayama, Sayama City, Saitama Prefecture Honda Engineering Co., Ltd. (72) Inventor Minoru Kobayashi 1-10-1 Shin-Sayama City, Sayama City, Saitama Prefecture Engineering Co., Ltd.

Claims (1)

[Claims] 1. A sensor selection circuit for selecting a desired sensor from a current sensor and a position sensor provided in each of a plurality of servo motors, and a desired one from an inverter circuit provided in each of the plurality of servo motors. An inverter selection circuit that selects an inverter circuit, a control information storage circuit that stores the control information of each servo motor, and a desired sensor that activates the sensor selection circuit based on servo motor selection information supplied from the outside. A control circuit for selecting a sensor, activating the inverter selection circuit to select a desired inverter circuit, reading desired control information from the control information storage circuit, and controlling the servo motor. Servo motor multi-axis controller.