JPS59191621A - Servo device - Google Patents

Abstract

PURPOSE:To prevent the generation of an overshoot by replacing an integrator with a control saturation integrator and at the same time adding a control saturator. CONSTITUTION:A control saturation integrator 11 has a function to saturate a target speed signal 12 with the prescribed value V; while an added control saturator 20 saturates a speed error signal 10 with the prescribed value A. When such an angle command signal is supplied that makes the signal 10 exceed the value A of the saturator 20, the input of the integrator 11 is limited. Thus the signal 12 is smoothly increased and never exceeds the value V. When the angle error is reduced and a speed signal 7 is smaller than the value V, the signal 10 becomes negative and the signal 20 is reduced. The change of the signal 20 is smooth. The target speed is set at 0 when the speed command is 0. Thus no overshoot is produced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a servo device that controls a controlled object to direct it to a commanded position.

A servo device that controls a radar antenna will be described below as an example of a controlled object.

Figure 1 shows an example of a conventional servo device of this type.
In the figure, (1) is an angle command signal, (2) is an angle signal,
(3) is the angle error calculator that calculates the difference between the angle command signal (1) and the angle signal (2) and outputs the angle error signal (4), and (5) amplifies the angle error signal (4). (6) is a management saturator (8) that saturates the output signal of the position amplifier at a constant value and outputs a speed command signal (7).
) is a speed error calculator that calculates the difference between the speed command signal (7) and the speed signal (9) and outputs a speed error signal fin, and I integrates the speed error signal fi1 and outputs a target speed signal (2). (2) is the integrator that calculates the target speed signal and the speed signal (
9), α4 is a servo amplifier that amplifies the output of the error calculator (13), (l is a motor driven by servo amplifier I, βQ is a drive mechanism, +1 is a rake Antenna, mark a is a speed detector that outputs a speed signal (9) proportional to the rotational speed of the motor;
αl is a position detector that outputs an angle signal (2) corresponding to the directivity angle of the radar antenna a71.

Next, the operation will be explained. When the command angle signal (1) is input, an angle error signal (4) corresponding to the difference between the command angle and the antenna angle is generated. This angle error signal (4) is amplified by a position amplifier (5). When the angle error exceeds a certain threshold, the output of the position amplifier (5) is controlled by the saturator (6).
As a result, the speed command signal (7) is saturated at a predetermined value. The speed command signal (7) is subtracted from the speed signal (9), then integrated by an integrator Qll to become a target speed signal, and then subtracted from the speed signal (9) and sent via the servo amplifier 04. Drive the motor. The motor 0!9 rotates the radar antenna completely through the drive mechanism 0e. At this time, the speed detector 0 seconds generates a speed signal (9) proportional to the speed of motor α9, but its polarity is the speed error signal f
The input of lJ and servo amplifier α is reduced. Further, the 9 position detector (11 generates an angle signal (2) corresponding to the angle of the radar antenna 0D).

Since the polarity is such that the angle error signal (4) is completely reduced, the system operates so that the angle of the radar antenna surface matches the angle command.

In such a servo device, when the radar antenna surface is stationary, the angle command signal (1) shown in Fig. 2 (a) is transmitted as the angle command signal (1).
The angular error signal when a step-like command is added is as shown in FIG. 2(b).

While the angle error signal (4) is greater than a certain threshold θ,
The speed command signal (7) is saturated at a constant value ■ as shown in Figure 2 (c), and when the angle error signal (4) becomes smaller than θ, the speed command signal (7) becomes the angle error signal (4). Proportional.

At first, the radar antenna aη is stopped, so the speed signal (9) increases from 0, and the speed error signal fi1 increases as shown in Fig. 2 (
d), and the target speed signal α is the integral value.
2 changes rapidly at first as shown in FIG. 2(e), exceeds the saturation value V of the speed command signal (7), and then converges to . The speed signal (9) changes in the same way as the target speed signal α.

When the angular error becomes smaller and the speed command signal (7) becomes smaller than ■, the speed error signal O1 becomes negative and the target speed signal 0 decreases. As in the case of acceleration, the change is sudden and becomes smaller than the speed command signal (7), the speed error signal III becomes positive, and the change in the target speed signal α2 is gradual, and the speed command signal (7) becomes smaller. The target speed signal becomes smaller than 0.

In order to decelerate in this manner, the target speed signal α oscillates above and below the speed command signal (7). Therefore.

Speed command signal (7) is 0. That is, even when the angle error signal becomes 0, the target speed signal does not become 0, but exceeds 0 and then converges to 0. The angular error once becomes 0, and then becomes 0 again as the radar antenna moves, resulting in a so-called overshoot.

As mentioned above, with conventional servo devices, even if the maximum speed is set, the actual speed exceeds that value and acceleration cannot be managed, so the motor a! The required torque of the motor α9 becomes large, and the speed cannot be limited, so the servo amplifier is lost, the motor α9 needs a large capacity, and it is necessary to increase the strength and rigidity of the drive mechanism fil. There was a drawback that it was not possible.

Furthermore, since the deceleration is not smooth during deceleration, the force received by the radar antenna αD is large, and the strength of the radar antenna αη must be increased, which also has the disadvantage of inevitably overshooting.

This invention was made to eliminate the drawbacks of conventional servo devices of this type.

A servo amplifier with the minimum necessary capacity to manage acceleration,
A motor and a drive mechanism with the minimum necessary strength and rigidity,
Consists of radar antenna.

To provide a servo device that does not overshoot.

FIG. 8 shows a configuration example of the present invention, and its operation will be explained in detail below.

In Fig. 8, (11') is a controlled saturation integrator with a function to saturate the target speed signal (L side) at a predetermined value, and C1l is a newly installed second controlled saturation integrator. The speed error signal layer is saturated at a predetermined value A.

In such a configuration, when an angle command signal is input such that the speed error signal 01 exceeds the predetermined value A of the second management saturator (excellent) as shown by the broken line in FIG. 4(d), the control saturation integrator The input of (11') is limited as shown by the solid line in Figure 4(d), the target speed signal 0 increases smoothly as shown in Figure 4(e), and the target speed signal 02 cannot exceed ■. do not have.

When the angular error becomes small and the speed command signal (7) becomes smaller than V, the speed error signal 01 becomes negative and the target speed signal - decreases, but the change is smooth as in the case of acceleration, and the speed command When is 00, the target speed is also 0 and there is no p overshoot.

Since this invention is configured and operates as described above,
Predetermined maximum speed no matter what angle command is input■
It is possible to realize a servo device that performs directional operation without exceeding the jerk, does not cause an unnecessarily large speed change to the motor or drive mechanism, and does not overseat.

Incidentally, in the above description, a radar antenna is used as an example of the object to be controlled, but the present invention is not limited to this, and an optical machine or the like may be used as the object to be controlled.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of a conventional radar servo device, Fig. 2 is a waveform diagram for explaining the operation of the conventional servo device, and Fig. 8 is a waveform diagram for explaining the operation of the conventional servo device.
FIG. 4 is a configuration diagram of a servo device according to the present invention, and FIG. 4 is a waveform diagram for explaining the operation of the servo device according to the present invention. In the figure, (1) is the angle command signal, (2) is the angle signal, and (3)
is the angle error calculator, (4) is the angle error signal, (5) is the position amplifier, (6) is the management saturator, (7j is the speed command signal, (8) is the speed error calculator, and (9) is the speed signal, 00 is the speed error signal, ■ is the integrator, (11') is the management saturation integrator, α2 is the target speed signal, (I3 is the error calculator, α(
A) is the servo amplifier, a4 is the motor, the mouse is the drive mechanism, the fin is the radar antenna, (1 & is the speed detector, +11 is the position detector, (2I is the second management saturator. Identical or equivalent parts are indicated with the same reference numerals. Fig. 2 JP-A-59-191G21 (4) Fig. 4 Time length 92

Claims (1)

[Claims] A servo device that controls a controlled object to direct it to a given command position includes a position amplifier that amplifies the deviation between the command position signal and the detected position signal, and a position amplifier that saturates the output of the position amplifier at a predetermined value. 1 managed saturator, and the first
a second managed saturator that saturates the deviation between the output of the managed saturator and the speed signal at a predetermined value; and a managed saturation integrator that integrates the output of the second managed saturator and saturates it at a predetermined value. a servo amplifier that amplifies the deviation between the output of the management saturation integrator and the speed signal; a motor that receives the output of the servo amplifier and drives the controlled object through a drive mechanism; A servo device comprising a speed detector that detects and generates a speed signal, and a position detector that detects the position of a controlled object.