JPS5864505A - Feedback control circuit for servo system - Google Patents

Abstract

PURPOSE:To obtain a control system with good response, by superposing the acceleration signal of a load upon the difference between an angle error signal and a speed feedback signal and thus generating a speed control signal for a motor in the feedback control circuit of a servo system for an antenna. CONSTITUTION:An arithmetic device 1 finds the difference between an angle command signal (a) and an angle feedback signal (f) to output an angle error signal (c). An arithmetic device 3 finds the difference between the signal (c) and a speed feedback signal (e) and superposes the acceleration signal (g) upon the difference to output a speed error signal (d). When this signal (d) is supplied through a compensating circuit 4 and a power amplifier 5, a motor 6 turns a load. Then, a speed detector 8 detects the speed of the motor 6 and feeds a signal (e) back to the arithmetic device 3. An angle detector 9, on the other hand, detects the rotational angle of the load 7 and feeds a signal (f) back to the arithmetic device 1. Further, an acceleration detector 10 detects the acceleration of the load and feeds a signal (g) back to the arithmetic device 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a feedback control circuit for a servo system such as an antenna servo system.

A conventional circuit of this type was constructed as shown in FIG. In the figure, 1 is an antenna angle command signal, (1) is a first arithmetic unit that takes the difference between the angle command signal a and an angle feedback signal f, which will be described later, and outputs an angle error signal, and (2) is this vgl. This is a first compensation circuit that compensates the angular error signal S, which is the output of the arithmetic unit 11, into a signal suitable for driving an antenna (7), which will be described later, to a desired angle with desired characteristics. (3) is a second arithmetic unit that takes the difference between the output C of this first compensation circuit (2) and a motor speed feedback signal e, which will be described later, and outputs a speed error signal d; A second compensation circuit (5) compensates the speed error signal d, which is the output of the arithmetic unit (3), into a signal suitable for driving a motor (6) with required characteristics, which will be described later. (6) is a motor to which the output power of this power amplifier (5) is applied;
7) is an antenna which is a load of this circuit driven by this motor (6); (8) is a speed detector that detects the speed of the motor (6) and outputs the speed feedback signal C; (9)
) is an angle detector that detects the rotation angle of the antenna (7) and outputs the angle feedback signal f. Further, in the figure, A is a velocity loop, and B is an angle (position) loop.

Next, the operation will be explained.

In this circuit, if you want to set the antenna at a predetermined angle, input the angle command (M number a) corresponding to the predetermined angle.Then, the first calculator (1) uses the angle command signal a to set the angle detector. (9) Angle bar I indicating the current angle of the antenna (7) detected by 2
) is compensated to a signal suitable for driving the antenna (7) with the required characteristics. The output C of this first compensation circuit D (21 is converted into speed feedback signals e and p indicating the speed of the motor (6) detected by the speed detector (8) by the second arithmetic unit (3), The speed error (Th
No. d is obtained. This speed error signal d is compensated by a second compensation circuit (4) into a signal suitable for controlling the speed of the motor (6) with the required characteristics, and this signal is amplified by a power amplifier (5). to drive the motor (6).

The motor (6) therefore rotates at the required speed up to the angle of the input angle signal 3 and drives the antenna (7) to said angle.

However, in this conventional antenna servo system feedback control circuit, only the speed signal from the motor is fed back in speed loop A, so the control loop bandwidth is limited by the resonant frequency determined by the load antenna structure. If the bandwidth is increased in an attempt to obtain an even faster response, the movement of the antenna becomes vibratory and the required electrical and mechanical performance cannot be obtained.
As a result, there was a drawback that a high-speed response could not be obtained.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and it feeds back not only the speed signal but also the acceleration signal of the load in the speed loop, so that the angle error signal and the speed control signal can be combined. By superimposing the acceleration signal of the load on the difference to create a motor speed control signal, it is possible to improve damping and respond even when the resonant frequency of the antenna 44 structure is low or when damping is poor according to the conventional method. It is an object of the present invention to provide a feedback control circuit for a servo system that provides a control system with good performance.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a feedback control circuit for an antenna servo system according to an embodiment of the present invention. In the figure, the same symbols as in Fig. 1 indicate the same parts as in Fig. 1, and fl (it is the antenna (7)
An acceleration detector that detects the acceleration of In the embodiment, the second arithmetic unit (3) is
The difference between the angular error signal, which is the output of the first compensation circuit (2), and the speed 1χ feedback signal e is determined, and the speed control signal d is created by superimposing the acceleration feedback signal on this with the opposite polarity. It looks like this.

According to the feedback control circuit 1i'3 of this embodiment, even if the resonant frequency of the antenna structure is low (in the conventional circuit, the movement of the antenna would be very vibratory), the acceleration feedback signal When the motor and the antenna structure begin to move apart near the resonance frequency due to the applied voltage, the feedback C signal controls the motor so that the movement of the antenna structure matches the movement of the motor, and damping is performed. By improving the servo system, the motor and antenna structure can operate as if they were a rigid body of (5) -q.Therefore, even if the resonance frequency is low, by appropriately applying an acceleration signal, the conventional servo system can be improved. A system with better responsiveness than -C1 can be obtained.

FIG. 3 shows, as an example, the response characteristics obtained by the present invention and the conventional feedback control circuit, where curve X shows the characteristic when the present invention is used, and curve V shows the characteristic when there is no feedback of the conventional acceleration signal. According to this figure, vibration occurs in the conventional method, but vibration is eliminated in the present invention, and it can be seen that the responsiveness is greatly improved.

Note that the present invention is not limited to the above-mentioned embodiment, and can of course be applied to a control system more complicated than the above-mentioned embodiment.

As described above, according to the present invention, in a feedback control circuit such as an antenna servo system, a speed control signal is created by also feeding back an acceleration signal in a speed acceleration loop, so that the resonant frequency of the antenna structure is low. (6) One effect is that damping can be improved and stable high-speed response can be obtained even in cases where vibration is likely to occur.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional feedback control circuit for an antenna servo system, FIG. 2 is a block diagram of a feedback control circuit for an antenna servo system according to an embodiment of the present invention, and FIG. FIG. 3 is a diagram showing response characteristics of a feedback control circuit according to an embodiment. a...Angle command signal, b...Angle error signal, C...
・Speed command signal, d...Speed error signal, C...Speed feedback signal, f...Angle 1y feedback signal, K...Acceleration 1v
Feedback signal, (1)...first computing unit, (3)...second computing unit, (6)...motor, (7)...load,
(8)...Speed detector, (9)...Angle detector, (
1o)...Acceleration detector. Agent Shin Kuzuno −

Claims (1)

[Claims] (1) A first computing unit that calculates the difference between the angle command signal and the angle feedback signal and outputs an angle error signal, and a first calculator that calculates the difference between the angle error signal and the speed feedback signal, and adds a load acceleration signal to this difference. a second arithmetic unit that outputs a speed error signal in a superimposed manner; a motor that rotationally drives a load to which the speed error signal is applied; a speed detector that detects a relationship between the motor and outputs the speed feedback signal; Feedback of a servo system characterized by comprising an angle detector that detects the rotation angle of the load and outputs the angle feedback signal, and an acceleration detector that detects the acceleration of the load and outputs the acceleration feedback signal. control circuit.