JPH02100113A - Controller for motor - Google Patents

Abstract

PURPOSE:To reduce the KP without increasing the number of bits of a D/A converter by setting the microvibration width of a servo-lock to the maximum resolution in spite of a gradual decreased rate in a feedback pulse gradual decrease system. CONSTITUTION:When a command pulse PP enters, a feedback pulse CCWP follows it up and returns, but since a pulse CCWP1 is outputted only when a count value of a cycle counter 16 is '2', the CCWP becomes a pulse frequency of six times, comparing with the CCWP1. That is, the pulse which is brought to six gradual decrease of the CCWP pulse becomes the CCWP1, and balanced with the command pulse PP. Subsequently, when the command pulse is gone and at the time of a servo-lock, when a CCW pulse enters in a state that the count value is '2', the CCWP1 pulse is outputted and the count value becomes '1', and when a CWP pulse enters, it is accompanied with a CWP1 pulse and the count value returns to '2'. That is, the microvibration width at the time of the servo-lock becomes the maximum resolution. In such a way, even if the KP is reduced, it becomes to unnecessary to increase the number of bits of a D/A converter.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electric motor control device configured to control the position of an electric motor.

[Conventional technology]

Figure 3 shows a two-phase pulse generator attached to a synchronous motor.
This is a general block diagram of a device that performs P1 stage electric motor device control. Figure 4 is a block diagram of a conventional device for the circuit section (9) that performs position control in Figure 3. a)
(6) is for reducing the feedback pulse by T (hereinafter referred to as type A), and (6) is for multiplying the command pulse by 7774 (hereinafter referred to as type B).

In the figure, (1) is a synchronous motor, (2) is a two-phase pulse generator, (3) is a current amplifier 2, (4) is a current feedback circuit, (5) is a speed amplifier, (6) is a speed feedback circuit, (7) is a position amplifier, [81 is a position feedback circuit, α・ is a two-phase pulse generator (
F.A.

Forward rotation pulse CCW when the motor is rotating forward from Pi3)
A circuit that outputs P and a reversing pulse OWP when the rotation is reversed, - Pulse PA for boat fishing, pulse aawp from PB
, when making cwp f, it is multiplied by 4 tees. αυ is determined by setting the tee reduction rate of the feedback pulse.
C2 is a command pulse (PP, NP or PP1.NPl).
and feedback pulse (ccwp, (!WP or c
0Wp1. C! A deviation counter that integrates the pulse difference from WP, ), (13 is the digital jt of the deviation counter
(141 is an amplifier for setting the position loop gain KP, αS is a D/A converter that converts the forward rotation command pulse PP and the reverse rotation command pulse NP into an analog signal, and Pulse PP1
．． This is a circuit for creating NP+.

Next, the operation will be explained. First, in FIG. 3, when the output (7), ie, the speed command, is applied, it is amplified by the speed amplifier (5), and a current command is added, causing current to flow to the motor and causing the motor to rotate. Then, it accelerates at 1, which is the same speed as the speed command. Next, FIG. 4(a) will be explained. For example, when a forward rotation command pulse pp is input, a pulse is sent to the counter, which is D/A converted and amplified to become a speed command.The motor rotates.◎When the motor rotates, a feedback pulse FA is generated.
, FB are input, and the normal rotation pulse ccwp is obtained by multiplying the number of pulses by 4T. And pulse tea reduction rate 17k
The pulse 0OWP1 reduced by T inputs a pulse to the deviation counter a2 in a direction that cancels PP.

When pp is input in this way, the frequency of pp and the 0OWP10 frequency match. Also, No. (4)
In the diagram (b), the command pulse PP is multiplied by the pulse T multiplier and PIJ is input to the deviation counter. Then, the frequencies of PP1 and C0WP match. FIG. 5 summarizes the above explanation. The figure shows the case of h:2, and the resolution per shaft-rotation of the motor is the same.

[Problem to be solved by the invention]

The conventional electric motor control device shows the movement at the time of servo lock as shown in Fig. 1<), which is the case when l(==5).As is clear from the figure, the feedback is reduced by , the minute vibration width θ of the motor is twice the maximum resolution determined by the two-phase pulse generator. Therefore, as the tee multiplier k increases, θ also increases. The sound is loud when you hit the crush.

In addition, since the command pulse shown in Fig. 6 (Koji) is multiplied by T, the feedback pulse frequency does not change depending on h.
It is not possible to increase k and decrease KP as shown in Figure (a). [In order to lower P, increase the variable range of the C4 amplifier.

The number of bits in the az deviation counter must be increased. That is, there are problems such as the need for a D/A converter with a large number of bits and the high cost of the circuit.

This invention was made to solve the above-mentioned problems, and the slight vibration at the time of servo lock is the same as the maximum resolution, and even if the KP is lowered, the number of bits of the D/A converter does not increase. The aim is to obtain a device that can be used easily.

[Means to solve the problem]

The electric motor control device according to the present invention is configured such that the minute vibration width at the time of servo lock is the maximum resolution of the two-phase pulse generator, regardless of the tee reduction rate of the feedback pulse.

[Effect]

The electric motor ILJ control device in this invention not only has the slight vibration width at the time of servo lock always at the maximum resolution (, Kp
can be easily obtained by increasing the feedback tee reduction rate.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. "No."
In the figure, C0 is the normal rotation feedback pulse acwp
upL, reverse feedback pulse CW
The cycle counter is configured to count dOWn at P, and the maximum value of sicrant changes depending on the tee reduction rate. In addition, (US passes the forward rotation pulse acwp'f only when the cycle counter has a certain count value,
A gate action is performed to generate pulse CCWP1. A reverse pulse CWP is passed at a count value different from the count value described above. Next, the operation will be explained. Now, the tee reduction rate = s
, oe is configured so that the pulse ccwp is passed when the count value of the cycle counter is 121, and the pulse CW1 is passed when the count value is 11'.

FIG. 2 is a time chart showing the operation. When the command pulse PP comes in, the feedback pulse ccwp returns to follow it, but only when the count value of the oe cycle counter is 12' is the pulse C!
In order not to issue 0WP1.

0OWP has a pulse frequency six times higher than ccWPl. That is, the pulse obtained by subtracting 6 points from the acwp pulse becomes 0CWPt and is combined with the command pulse PP. Next, when there is no command pulse and the robot is locked,
When the count value is 12' and a CCW pulse is input, cawp1
A pulse is emitted and the count value becomes 11'. Next, cwp
Pulse is input.

The count value returns to 12' with the CWP+ pulse.

In other words, when the servo is locked, type B and β1 in Figure 4 are used.
(The slight vibration width at the time of servo lock is the maximum resolution).

〔Effect of the invention〕

As described above, according to the present invention, since the feedback pulse tee reduction method is used and the minute vibration width of the servo lock is configured to have a high resolution regardless of the tee reduction rate, D
It is possible to reduce KP without increasing the number of bits of the /A converter or deviation counter.It is not an inexpensive device, and the accuracy of the minute vibration amplitude at the time of servo lock is the same as that of the command pulse tee multiplication method. There are benefits to be gained.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a position control part according to an embodiment of the present invention, FIG. 2 is a diagram showing a time chart for explaining the operation of the present invention, and FIG. 3 is a general diagram of a position control device for a synchronous motor. block diagram. FIG. 4 is a block diagram of a position control portion of a conventional device. FIG. 5 is a diagram showing a time chart when a command pulse is input in the conventional device, and FIG. 6 is an explanatory diagram of the operation of the conventional device when the servo is locked. In the figure, (1) is a synchronous motor, (2) is a two-phase pulse generator, Ql is a forward/reverse pulse generation circuit, αυ is a pulse tee reduction circuit, α9 is a pulse stay multiplier circuit, and αe is a pulse tee reduction circuit with a built-in cycle counter. be. Note that the same reference numerals j in Figure 1 indicate the same or equivalent parts. Figure 1

Claims (1)

[Claims] A device that uses the pulse signal of a two-phase pulse generator directly connected to the shaft of the motor as a feedback signal to control the rotational position of the motor in response to a position command, and multiplies or subtracts the pulse signal to generate a signal per revolution of the motor shaft. In a device configured to be able to vary the resolution of The micro-vibration width when the motor is stopped (that is, when the motor is servo-locked) is configured to be the highest resolution width determined from the pulse signal, regardless of the above-mentioned Tay multiplication factor and Tay reduction rate. A control device for an electric motor.