JPH099662A - Motor control device - Google Patents

Abstract

PURPOSE: To maintain an optimum gain always by providing an auto tuning section for identifying load inertia, a gain reading section for reading a gain stored in accordance with a command value and an output, and a feedback loop. CONSTITUTION: Turning to an optimum gain is performed by repeating a cycle of determining a gain in an auto tuning section 1 from an output (c) and the quantity-of-operation (b) to a command value (a), and giving a corrected quantity of the gain (d), to a controller 2. This one pattern is sampled, and a gain value (e) to be stored is stored in a gain storing section 4 making the command value (a) and the output (c) as an address. At the time of real operation, a command value (a) and an output (c) are read in a gain reading section 5 every constant time, and address commanding (f) of the gain storing section 4 is performed. The gain storing section 4 inputs a gain value stored at a designated address to the controller 2 as a gain direction (g).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a feedback loop for controlling a mechanical system, and aims to perform optimum control of a mechanical system that performs a constant repetitive operation by varying a control gain. The present invention relates to a control device.

[0002]

2. Description of the Related Art In recent years, servo motors have been widely used for controlling machines, but it has been necessary to appropriately adjust the gain of a control system according to the characteristics of the machine. Conventionally, this research work has often relied on manual labor, but since it requires specialized knowledge, auto-tuning in which the control device itself automatically sets the optimum gain is being put to practical use. In this auto tuning, there is a method of fixing the gain during the operation of the machine, which is limited to the initial gain adjustment, and a method of changing the gain according to the fluctuation of the load inertia even during the operation.

A conventional motor control device adopting the above-mentioned auto tuning method will be described below.

FIG. 2 is a block diagram of a conventional motor control device. In FIG. 2, reference numeral 1 is an auto tuning unit, 2 is a controller, and 3 is a mechanical system load including a motor to be controlled.

The operation of the motor control device configured as described above will be described below. First, in the auto tuning method in which only initial gain adjustment is performed, a command value (a) of a certain specific pattern is generated, and an operation amount (b) that is an output of the controller 2 with respect to this command value,
The output (c) of the controlled object 3 is calculated by the auto tuning unit 1 and the gain correction amount (d) is given to the controller 2 so that the output (c) becomes a predetermined optimum value. For example, when the command value (a) is given in steps, the current value which becomes the operation amount (b) and the rise time and overshoot amount of the controlled object which becomes the output (c) are read, and the operation of gain correction is continued.

On the other hand, in the auto tuning system in which the gain is changed according to the change of the load inertia even during operation,
Read the command value (a) that changes from time to time at regular intervals,
The load inertia is identified from the operation amount (b) and the output (c) for this command value (a), and the gain correction amount (d) is determined. By performing this series of calculations at high speed, real-time gain tuning becomes possible.

[0007]

However, the above-described conventional tuning method has the following problems. First, with the method that only performs initial gain adjustment, it is difficult to change the gain with respect to changes in load inertia, and it is not possible to always maintain the optimum gain in a series of operations, which leads to deterioration of positioning performance and further load inertia. There is a problem in that it cannot be used in applications that change drastically.

Further, in the method of performing the gain tuning by performing the calculation in real time, the calculation requires a huge amount of time, which deteriorates the responsiveness and is not suitable for applications such as high-speed positioning. However, there is a problem in that the cost of the circuit element is high.

The present invention solves the above-mentioned conventional problems by changing the gain according to the change of the load inertia,
An object of the present invention is to provide a motor control device that can inexpensively realize always maintaining an optimum gain even for high-speed operation.

[0010]

In order to achieve this object, a motor control device of the present invention has an automatic tuning section for initially identifying a load inertia from a series of operations, and a gain storage section for storing a determined gain. And a gain reading unit for reading the stored gain according to the command value and the output, and a feedback loop.

[0011]

With this configuration, the motor control device of the present invention first repeats some patterned operations to determine the gain for each pattern in the auto tuning section from the command value, the manipulated variable and the output, and store the gain. An address is designated and stored in the section according to the command value and the output. Then, in practical use, the gain of the corresponding address is read from the command value and output at regular time intervals by the gain reading unit, and the gain of the controller can be changed in an extremely short time without performing tuning work, and the optimum gain according to changes in load inertia can be obtained. You can set the gain.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a motor controller which is an embodiment of the present invention. In FIG. 1, 1 is an auto tuning unit, 2 is a controller, 3 is a control target, 4 is a gain storage unit, and 5 is a gain reading unit.

The operation of the motor control device configured as described above will be described below. First, the gain is tuned before the actual operation is started, but the actual operation is divided into some patterns and the patterns are repeated to obtain the optimum gain. From the operation amount (b) and the output (c) for the command value (a), the auto tuning unit 1
The gain is determined by, and the optimum gain is tuned by repeating the cycle of giving the gain correction amount (d) to the controller 2. This one pattern is sampled at regular intervals, and the command value (a) and output (c) are output to the gain storage unit 4.
Is used as an address to store the stored gain value (e). This work is performed for some patterns to determine the gain value determined by the combination of the command value (a) and the output (c).

Next, at the time of actual operation, the gain reading unit 5 reads the command value (a) and the output (c) at regular intervals, and issues the address command (f) of the gain storage unit 4. The gain storage unit 4 uses the gain value stored in the designated address as the gain instruction (g) and the controller 2
Enter With the above operation, in practical use, the gain can be maintained in the optimum state in real time without performing the tuning work.

[0016]

As described above, the present invention is provided with the gain storage section for storing the gain determined by the automatic tuning operation according to the command value and the output, and the gain reading section for reading the gain and changing the gain of the controller. As a result, even if high-speed calculation is not performed using expensive elements,
In practical use, the gain can be changed in real time according to the change in the load inertia, and an excellent motor control device that can always maintain the optimum gain is realized.

[Brief description of drawings]

FIG. 1 is a block diagram of a motor control device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a conventional motor control device having an auto tuning function.

[Explanation of symbols]

 1 Auto-tuning unit 2 Controller 3 Control target 4 Gain storage unit 5 Gain reading unit (a) Command value (b) Operation amount (c) Output (d) Gain correction amount (e) Gain stored value (f) Address command (g ) Gain instruction

Claims (1)

[Claims] 1. An auto-tuning unit for automatically determining a control gain by measuring a magnitude of load inertia of a mechanical system to be controlled by a motor, a gain storage unit for storing the determined gain, a command value and an output. A motor control device including a controller configured with a gain reading unit that reads out the gain stored by and a feedback loop.