JPS58141692A - Synchronous operation control system - Google Patents

Abstract

PURPOSE:To improve the follow-up of a synchronization side motor by detecting the angular acceleration of an instruction side motor and adding the acceleration to the current command of the synchronization side motor. CONSTITUTION:An instruction side motor 101 rotates at a speed in response to the generating speed of a command pulse CMP. A speed feedback pulse FP1 which is proportional to the rotating speed of an instruction side motor 101 is generated from a pulse coder 102, and an active speed voltage signal AVS1 which is proportional to the rotating speed of the instruction side motor 101 is generated from a tachometer generator 103. The pulse FP1 becomes the command pulse of a synchronous motor 210, inputted to the error arithmetic memory 204a of a servo circuit 204, and the actual speed voltage signal AVS1 is differentiated by a differentiator 205 and inputted to an arithmetic unit 204g of the servo circuit 204. The circuit 204 rotates the synchronization side motor 201 in synchronization with the motor 101.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synchronous operation control method, and particularly to a synchronous operation control method for rotating two motors, a command side motor and a synchronous side motor, in synchronization.

The need to operate two motors in synchronization arises in feed control of large machine tools, drafting machines, and the like. For example, an IJ type machine tool (gun) is moved and positioned in one predetermined axis direction by two feed motors. In such a case, it is necessary to send the two feed motors in complete synchronization, and if the synchronization is disrupted, machining accuracy will be reduced or the machine tool will be twisted, causing damage to the machine tool.

For this reason, various synchronous operation control methods have been proposed in the past, but they have the disadvantage that when the feed speed becomes high or the speed fluctuations become large, the tracking error becomes large and complete synchronization cannot be achieved.

Therefore, it is an object of the present invention to provide a new synchronous operation control system that allows two motors to operate synchronously even when the speed of the wheelchair becomes high or the speed fluctuations become large.

Embodiments of the present invention will be described in detail below with reference to the drawings.

The figure is a block diagram showing an embodiment of the present invention.

Reference numerals 101 and 201 represent a command side motor and a synchronous side motor, respectively, which are constructed of, for example, a DC motor.

The synchronous feeding motor 201 is controlled to rotate in synchronization with the rotation of the command side motor 101, and the command side motor 101 is controlled to rotate at a command speed by servo control. 102
10 is a pulse coder that generates one feedback pulse Fl'P1 every time the command side motor 101 rotates by a predetermined amount; 103 is a tacho generator that generates an actual speed voltage signal AVS1 according to the rotational speed of the command side motor 101;
4 is a well-known servo circuit having the same configuration as a servo circuit 204 described later. To this servo circuit 104, for example, a distribution pulse outputted from an NO cover (not shown) is inputted as a command pulse OMP, and feedback pulses F'P1. An actual speed voltage signal AV81 generated from the tacho generator 103 is input as a position feedback signal and a speed feedback signal, respectively.

202 is 1 every time the synchronous side motor 201 rotates by a predetermined amount.
A pulse coder that generates 203 feedback pulses FP2, and a tachogenerator that generates an actual speed voltage signal AVS2 according to the rotational speed of the synchronous side motor 201%2.
04 is a servo circuit, and 205 is a differential circuit, which differentiates the actual speed voltage signal AVS1 of the command side motor 101 from 1 to 1 and outputs the differential value thereof, or the differential value multiplied by a predetermined gain.

The rotational position of the command side motor 101, in other words, the feedback pulse FPt generated from the pulse coder 102 is input to the servo circuit 204 as a command pulse, and the feedback FP2 generated from the pulse coder 202 and the actual speed voltage signal generated from the tacho generator 205 are input to the servo circuit 204. A.V.
S2 is input as a position feedback signal and a speed feedback signal, respectively. Feedback pulse FP1. generated from the 204m Haharu coder 102.202. Difference in FP2 (
This is an error calculation storage section that calculates and stores the error (referred to as an error), and is composed of a gate circuit, a reversible counter, and the like. The error calculation storage section 204a adds feedback pulse FP1 and subtracts feedback pulse FP2 when the rotation direction is positive, and subtracts feedback pulse FP1 and adds feedback pulse FP2 when the rotation direction is negative. . 204b is error calculation memory 1! ! 20
The DA converter 204C generates an analog voltage (speed command voltage signal) VOMDI proportional to the error FSr stored in 4m, and the DA converter 204C generates the actual speed voltage signal AVS2 and the speed command voltage signal multiplied by the amplifier 204d. 204e is an amplifier that multiplies the speed command voltage signal old by Kv to generate a current command Ic; 204f is the synchronous side motor 201;
A current transformer 204g that detects the armature current Ia is a second calculation unit. This second arithmetic unit 204g is a differential circuit 2
If the output of 05 is Id, Ic + Id - Ia = I
The calculation (1) is performed and the calculation result I is output.

204h is an amplifier that amplifies the output of the second calculation unit 204g, and 2041 is the output of the amplifier 204h and the amplifier 204j.
A third calculation unit 204m that calculates the difference between the actual speed voltage kV82 multiplied by Ke and 204m is a main power circuit, and includes a voltage/phase converter, a transistor or a thyristor circuit, and the like. Note that the servo circuit 104 has substantially the same configuration as the servo circuit 204. However, the servo circuit 104 is different in that a distribution pulse is inputted as a command signal from an NO device (not shown) and that the output of a differentiating circuit is not inputted thereto.

Next, a synchronous operation control method according to the present invention will be explained with reference to the drawings.

The command side motor 101 is based on the command pulse OMF.

It rotates at a speed corresponding to the generation speed (command speed) K of the command pulse OMP. Then, the pulse coder 102 generates a feedback pulse FP1 having a speed proportional to the rotation speed of the command side motor 101, and the tacho generator 103 generates an actual speed voltage signal AV81 proportional to the rotation speed of the command side motor 101.

The feedback pulse FP1 becomes a command pulse for the synchronous motor 201 and is sent to the error calculation storage section 2 of the servo circuit 204.
04m, and the actual speed voltage signal AV81 is differentiated by the differentiating circuit 205K to become Id, which is input to the second calculation section 204gK of the servo circuit 204.

Feedback pulse FP1 is sent to the error calculation storage section 204m.
is applied and an error Er occurs, the error Er becomes DA
It is DA-converted by the converter 204bK, becomes the speed command voltage signal VOMD, and is input to the first calculation section 204C. The first calculation unit 204C outputs a speed command voltage signal VOMD.
and the actual speed signal ^V generated from the tacho generator 203
The difference between the signal obtained by multiplying S2 by Kg is calculated as 9, and the cough difference is output as a speed deviation voltage signal VER. Amplifier 204@-f
is the speed deviation voltage signal VBR multiplied by Kv and outputs the current command Ic and L5 to the second calculation section 204g. This second calculation section further includes the output Id of the differentiating circuit 205 and the current transformer 2.
The armature current Ia detected by 04f is inputted, and the calculation of equation (a) is performed at 704
i K is input. Then, here is the actual speed voltage signal AV
The difference between the signal S2 and the signal obtained by multiplying S2 by Ke is taken, and a portion of the power is inputted to the main circuit 204m, which controls firing of the thyristor and rotationally drives the synchronous side motor 201. When the synchronous motor 201 rotates, the pulse coder 202 outputs a feedback pulse FP2, and the tachogenerator 205 outputs an actual speed voltage signal AV.
82 occur respectively.

The feedback pulse FP2 is stored in the error calculation storage section 204a.
and operates to reduce its contents (error) Er. As a result, the error Er stored in the error calculation storage unit 204a is expressed as Er = f17/k (2
After maintaining the constant value (steady deviation value) indicated by j, the synchronous side motor 201 rotates in synchronization with the command side motor 101.

In the case where the servo system on the synchronization side does not have a differential correction circuit, the input command position is 01 and the actually moved position is 00, then dt9° --=: K (e5-00) dt.

However, K is a position loop gain, and if the error me (IEII) between the command θi and the amount of movement is K, it is a constant indicating that the error is corrected at a speed of 67 wg. That is, the above equation shows that the rotation is performed at a speed proportional to the difference (position w error) K between the input command 0i and the movement position θ07, which is a characteristic of a -order lag system. At this time, the cutoff frequency is 2/2πHz, which indicates that even if a steeper input is input, the response will be poor. In general, in a control system that has multiple foot-nosic loops, we focused on the fact that the minor loop has a stormy frequency characteristic, that is, it has good response.The present invention detects the angular acceleration to the command-side motor and converts this acceleration. By adding the current command (torque command) K of the synchronous motor, the follow-up performance of the synchronous motor is improved.

In conventional servo systems with a first-order delay, if the command motor accelerates suddenly or a large instantaneous load is applied to the command inertia motor, causing speed fluctuations, the following error cannot be corrected, resulting in a large synchronization error and the motor When installed on a machine, it causes stress, twisting, etc. on the machine side, but by applying the present invention, it has become possible to eliminate these problems.

[Brief explanation of drawings]

The figure is a block diagram of an embodiment of the invention. 101... Command side motor, 102... Pulse coder, 103... Tacho generator, 104... Servo circuit, 201... Synchronous side motor, 202... Pulse coder, 20! l...Tachogenerator, 2D4...
・Dabo circuit.

Claims (1)

[Claims] In a synchronous operation control method that rotates two motors in synchronization, the rotational position of the command side motor is used as the position command of the motor to be synchronized, and the differential value of the speed signal of the command side motor or a value corresponding to this is synchronized. A synchronous operation control method characterized by adding the current command to the side motor current command.