JPH02127708A - Motor controller - Google Patents

Abstract

PURPOSE:To form a high-speed and inexpensive system when the position of a motor is controlled with use of a sensor that can output only the analog output by realizing the input of a position command in an analog quantity. CONSTITUTION:The position control of a motor 1 is possible with reception of the input of an analog quantity and at the same time the value of the analog quantity and the position control unit of the motor 1 can be controlled. In addition, the input of a digital quantity (pulse) is also possible. In other words, an amplifier 9 is prepared to receive the input of the position command of the analog quantity and to control the gains to vary and set the value of the analog input per resolution unit value of the motor 1. Thus it is possible to obtain such a system that inputs the output of a sensor which outputs the analog quantity directly to the controller of the motor 1 and can control the position of the motor 1 at a high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a control device for controlling the rotational position of an electric motor.

[Conventional technology]

FIG. 2 is a general block diagram in which a two-phase pulse generator (encoder) is attached to a conventional synchronous motor to control the position of the synchronous motor. In the figure, (1) is a synchronous motor, (2) is an encoder, (3) is a current amplifier, and (41) is a synchronous motor.
1'i current feedback circuit, 5) speed amplifier,
(6) is a velocity feed pack circuit, (7) is a position amplifier, and (8) is a position feed pack circuit.

Next, the operation will be explained. Now 1st position command pulse Dre
When f is input, the product of the position command Dref, the position feed pack PfbO difference, and the position amplification gain G in (7) (Dref Pfb) Gp's speed command Vre
f occurs. Similarly, set the speed feed pack to Vfb.

If the speed amplifier gain is Gy, the current command is Iref, the current feed pack is Ifb, and the current amplifier gain is G, then (Vref Vfb) Gy only ¥
An It flow command is generated, a current of (xret-rrb)G flows through, and the motor generates torque and rotates. Here, if Gv is extremely large, Vref # Vfb
That is, the speed command and the speed feed pack almost match. Also, since vre f is a finite value, Dref and P
The frequency of fb always matches, and the number of pulses of #Dref and the number of pulses of Pfb match. In other words, the motor rotates by the number of one position command pulse. Therefore, the position of the electric motor can be freely controlled by one position command pulse.

[Problems to be solved by the invention]

Since the conventional electric motor control device was configured as described above, 'l! In order to control the position of the motive force, pulse commands (including digital commands) must be given.

However, when a motor control device configured in this manner is used to perform tracking control of a moving machine, for example, and a sensor (such as a voltometer) that outputs an analog quantity is used as a position detector for the moving machine. If you want to control the position using an analog quantity, as in the case of using the analog quantity, it is necessary to convert the analog quantity into a pulse command. To create such a system, a general-purpose programmable controller (PC) is required.
etc., it takes an extremely long time to convert from analog to pulse and perform zero position control.

In addition, the system also had the problem of being large-scale and expensive.

This invention was made to solve the above-mentioned problems, and it is possible to configure a system that can perform high-speed position control by inputting the output of a sensor that outputs an analog quantity as it is to a motor control device. It is intended to.

[Means to solve the problem]

The electric motor control device according to the present invention is capable of controlling the position of the electric motor upon receiving the input of an analog quantity, and is also capable of adjusting the magnitude of the analog quantity and the position control unit of the electric motor. , digital quantities (pulses) can also be input.

[Effect]

In controlling the electric motor in this invention, the position of the electric motor is controlled by receiving analog input, and the position of the electric motor can also be controlled by digital input.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (9) is an amplifier capable of receiving an analog position command input and adjusting the gain to vary and set the magnitude of the analog input per unit resolution of the motor.

Next, the operation will be explained. The operation when the digital quantity Dref is input is the same as in the conventional example, and will therefore be omitted. If analog quantity Aref is now input with digital input Dref==0, current command I ref =
Gy (A'ref1 + Vref - Vrf)
becomes. However, immediately after Aref is input, V
Since ref := 0, the electric motor rotates as a current flows according to the current command Iref. When it started rotating, -Pfb came in. It is stored and Vref
=-GpPfb and Nasi.

Iref gradually decreases and Arefl = Vre
When it reaches f, Iref==O and the motor stops. That is, if the gain in (9) is Ga, then GaAr
The electric motor can be stopped at a position where ef:=GpPfb holds true.

Therefore, if the gain of Ga can be adjusted, the magnitude of the analog input voltage in units of resolution of the motor can be adjusted. In this way, in the case of a large amount of power, the electric motor stops at the position where GaAref: GpPfb is established and cannot be rotated continuously. Therefore, when rotating continuously, digital quantity input is used.

It should be noted that the magnitude of the position command analog quantity for moving the position of the motor by a unit amount of resolution determined by the two-phase pulse generator may be variable or settable, or the magnitude of the position command analog quantity of digital quantity and analog quantity may be changed. The position commands may be switched or input at the same time.

〔Effect of the invention〕

As described above, according to the present invention, since the position command is configured to be input as an analog quantity, when controlling the position of the electric motor using a sensor etc. that can only output analog output, it is possible to control the position of the electric motor at high speed and at low cost. This has the effect that the system can be configured.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a motor control device according to an embodiment of this invention, and FIG. 2 is a block diagram of a conventional device. In the figure, (l) is a synchronous motor, (2) is a two-phase pulse generator, (7) is a position amplifier, (8) is a position feedback circuit, and (9) is a variable gain amplifier. Note that the same reference numerals in Figure 9 indicate the same or equivalent parts.

Claims (1)

[Claims] In a device that uses the pulse signal of a two-phase pulse generator directly connected to the shaft of the motor as a feed pack signal, and controls the rotational position of the motor in response to a position command, in addition to position commands based on digital quantities (including pulse commands), analog An electric motor control device configured to receive a position command of a quantity and control the rotational position of the electric motor according to the magnitude of the analog quantity.