JPH03282605A - Follow-up control method between two servo systems - Google Patents

Abstract

PURPOSE:To attain the highly accurate synchronous control even in a transient state by applying a 3rd correction coefficient obtained from a follow-up deviation to the 1st and 2nd correction signals respectively. CONSTITUTION:A position command XS of a 2nd servo system obtained by sampling the position detection signal XS of a 1st servo system is applied by a correction coefficient K1 for acquisition of a 1st correction signal. Meanwhile a speed command (f) of the 1st servo system is applied by a correction coefficient K2 for acquisition of a 2nd correction signal. The follow-up deviation of the 2nd servo system set to the 1st servo system is inputted to a compensator H. A 3rd correction signal is obtained from the output of the compensator H. These 1st - 3rd correction signals are added together for correction of the speed deviation of the 2nd servo system. In such a constitution, the highly accurate synchronous control is attained even in a transient state.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a signal obtained by sampling a position detection signal of a first servo system having a speed closed circuit control system as a minor loop and digitally processing the signal. Tracking between two servo systems that causes the behavior of the second servo system to follow the behavior of the first servo system by using the closed-circuit speed control system as a position command signal for the second servo system as a minor loop. Regarding control method.

[Prior Art] Conventionally, in this type of follow-up control method between two servo systems, the following six methods have been proposed in Japanese Patent Laid-Open No. 63-268011, which enable synchronized control of two →novo systems with different response characteristics.
No.

(1) generating a first correction signal according to the position detection signal of the first servo system and a second correction signal according to the speed information obtained from the speed command signal of the first servo system; These first and second correction signals correct the speed deviation of the speed control system of the second servo system.

(2) generating a first correction signal according to the position detection signal of the first servo system and a second correction signal according to the speed information obtained from the position command signal of the first servo system; These first and second correction signals correct the speed deviation of the speed control system of the second servo system.

(3) A first correction signal according to the position detection signal of the first servo system, and a second correction according to the speed information obtained from the speed command signal and position command signal of the first servo system. A signal is generated, and the speed deviation of the speed control system of the second servo system is corrected using these first and second correction signals.

(4) A first correction signal according to the speed information obtained from the position detection signal of the first servo system, and a second correction signal according to the speed information obtained from the speed command signal of the first servo system. A correction signal is generated, and the speed deviation of the speed control system of the second servo system is corrected using these first and second correction signals.

(5) A first correction signal corresponding to the speed information obtained from the position detection signal of the first servo system, and a first correction signal corresponding to the speed information obtained from the position command signal of the first servo system. The first and second correction signals are used to generate the first and second correction signals.
Correct the speed deviation of the servo system.

(6) A first correction signal corresponding to the speed information obtained from the position detection signal of the first servo system and speed information obtained from the speed command signal and position command signal of the first servo system. A corresponding second correction signal is generated, and the speed deviation of the speed control system of the second servo system is corrected using these first and second correction signals.

In the above case, the correction coefficient indicating the influence of these two correction signals, that is, the correction coefficient by which the position detection signal and speed information are multiplied, is 2.
This was based on the condition that complete synchronous control be carried out between the two power systems in a steady state.

Fig. 6 is a block diagram of the control system showing the method [1) of JP-A No. 63-268011, and Fig. 7 (a), et al.
FIG. 3 is a diagram showing command values and their response waveforms in a transient state and a steady state, respectively, when a ramp-like speed command is given to the system shown in the figure. Here, the speed command is converted into a position command.

The loop in the upper row of FIG. 6 is the first servo system (a system with a slow response), and the loop in the lower row is a second servo system (a system with a fast response). K5 and K2 are the proportional gains of the position loop, G
3. G2 is the transfer function, f (t) is the speed command, f (τ
) d(τ) is the position command, Xs, Xz is the speed X, , x
z H position i, k are constants, K is a correction coefficient for the response, 2 is a correction coefficient for the command, and D is a sampling circuit.

In FIG. 7, r@<If(τ)dτ) is a position command for the first servo system, and r2 is a position command for the second servo system. In this case, synchronous control is performed with respect to the speed command in the steady state (Fig. 7, etc.), but in the transient state, the speed command is approximately 4.11%.
A deviation of X 10-' occurs, and strict synchronization is not established (FIG. 7(a)).

[Problem to be solved by the invention]

The above-described conventional follow-up control method between two servos requires synchronous control in a steady state, but has the disadvantage that a speed deviation occurs in a transient state and synchronization is no longer established.

An object of the present invention is to provide a synchronous control method between two servo systems that enables highly accurate synchronous control even in a transient state.

[Means to solve the problem]

The first invention provides a signal obtained by sampling and digitally processing the position detection signal of a first servo system, which has a closed-circuit control system for speed as a minor loop, and a second system, which has a closed-circuit control system for speed as a minor loop. By setting the position command signal of the servo system to , the behavior of the second servo system is made to follow the behavior of the first servo system, and at this time, the position detection signal of the first servo system is multiplied by the first correction coefficient. generates a first correction signal, and the speed information obtained from the speed command signal of the first servo system or the speed information obtained from the position command value of the first servo system or the first servo system The speed information obtained from the speed command signal and position command signal is multiplied by a second correction coefficient to generate a second correction signal, and these first and second
In a follow-up control method between two servo systems, in which a speed deviation of a speed control system of a second servo system is corrected using a correction signal of
The following deviation between the two servo systems is input to a compensator, and the output of this compensator is used as a third servo system to correct the speed deviation of the second servo system.
This correction signal is used to reduce the following deviation of the second servo system in a transient state.

The second invention is a first servo system which has a speed closed circuit control system as a minor loop, and a signal obtained by sampling and digitally processing the position detection signal of the first servo system, which has a speed closed circuit control system as a minor loop. By using the position command signal for the second servo system, the behavior of the second servo system can be changed to the first position command signal.
A first correction signal is generated by multiplying the speed information obtained from the position detection signal of the first servo system by a first correction coefficient. Speed information obtained from a speed command signal, speed information obtained from a position command signal of the first servo system, or speed information obtained from a speed command signal and a position command signal of the first servo system. Follow-up control of two servo systems that generates a second correction signal by multiplying by a second correction coefficient, and corrects the speed deviation of the speed control system of the second servo system using these first and second correction signals. In the method, the following deviation between the two servo systems is input to a compensator, and the output of the compensator is used as a third correction signal for correcting the speed deviation of the second servo system. This is to reduce the following deviation of the servo system.

[Effect]

By the above means, in a transient state due to a change in the command pattern, the following deviation of the second servo system with respect to the first servo system is manually inputted to the compensator, and the output of this compensator is added to the command value of the second servo system. As a result, the command value of the second servo system increases in a transient state, and the follow-up deviation can be rapidly driven to zero.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a control system consisting of two servo systems, showing the first embodiment of the present invention, and FIGS. 2(a) and (b)
1 is a diagram showing command values and their response waveforms in a transient state and a steady state, respectively, when a ramp-shaped speed command is given to the first control system. The same symbols as in FIG. 6 indicate the same things.

This embodiment corresponds to the method (1) of JP-A No. 63-268011, and uses the position command X of the second servo system obtained by sampling the position detection signal X of the first servo system. A first correction signal is obtained by multiplying the correction coefficient by 1, and a second correction signal is obtained by multiplying the correction coefficient by 2 for the speed command f(λ) of the first servo system.
, the following deviation of the second servo system with respect to the first servo system is input to the compensator H, a third correction signal is obtained from the output of this compensator, and these first, second, and The speed deviation of the speed control system of the second servo system is corrected by adding the three correction signals.

Here, 1, K2 is the conventional correction coefficient (Fig. 6), and the compensator is K. PID expressed as (1+1/T is+Tds)
The controller and its constant are Kc=100 Ti-20
Td=10. As can be seen from FIG. 2 [1], by appropriately selecting Kc, Ti, and Td, the second servo system can follow the first servo system well even in a transient state.

[2), (4), [5] of JP-A-63-268011
Examples corresponding to the method described above are shown in FIGS. 3, 4, and 5, respectively, and the same results can be obtained with these examples. In addition, (3) of JP-A-63-268011, (
In the embodiment of method 6), the second correction signal is obtained from the speed command f(λ) and position command Sf(τ)dr of the first servo system, and illustration thereof is omitted.

〔Effect of the invention〕

As described above, the present invention has the effect of enabling highly accurate synchronous control even in a transient state by adding the third correction coefficient created from the tracking deviation to the first and second correction signals.

[Brief Description of the Drawings] Fig. 1 is a block diagram of a control system consisting of two sabot systems showing a first embodiment of the present invention, and Fig. 2 shows a ramp-shaped speed command for the control system of Fig. 1. FIGS. 3, 4, and 5 are block diagrams of control systems according to other embodiments of the present invention. The figure is a block diagram of a control system showing a conventional example, and Figure 7 is a diagram showing the command value and its response waveform in a transient response steady state when a ramp-shaped speed command is given to the control system in Figure 6. be.

Claims (3)

[Claims] (1) A signal obtained by sampling the position detection signal of the first servo system, which has a speed closed-circuit control system as a minor loop, and digitally processing the signal is sent to a second servo system, which has a speed closed-circuit control system as a minor loop. By using the position command signal of the system, the behavior of the second servo system is made to follow the behavior of the first servo system, and at this time, the position detection signal of the first servo system is multiplied by the first correction coefficient to obtain the first servo system. 1 correction signal, and generates speed information obtained from the speed command signal of the first servo system, speed information obtained from the position command signal of the first servo system, or speed information of the first servo system. A second correction signal is generated by multiplying the speed information obtained from the command signal and the position command signal by a second correction coefficient, and these first and second correction signals are used to control the speed control system of the second servo system. In a follow-up control method between two servo systems that corrects the speed deviation of the second servo system, the follow-up deviation between the two servos is input to a compensator, and the output of this compensator is used to correct the speed deviation of the speed control system of the second servo system. A follow-up control method between two servo systems, characterized in that a third correction signal for correcting is used as a third correction signal. (2) The position detection signal of the first servo system, which has a closed-circuit speed control system as a minor loop, is sampled and digitally processed. By using the system position command signal, the behavior of the second servo system is made to follow the behavior of the first servo system, and at this time, the speed information obtained from the position detection signal of the first servo system is combined with the first servo system. A first correction signal is generated by multiplying by a correction coefficient, and the speed information obtained from the command signal for the speed of the first servo system or the speed information obtained from the command signal for the position of the first servo system or the first A second correction signal is generated by multiplying the speed information obtained from the speed command signal and position command signal of the servo system by a second correction coefficient, and these first and second correction signals are used to generate a second correction signal. In a follow-up control method between two servo systems that corrects the speed deviation of the speed control system of the servo system, the follow-up deviation between the two servos is input to a compensator, and the output of this compensator is used as the output of the second servo system. A follow-up control method between two servo systems, characterized in that a third correction signal is used to correct a speed deviation. (3) The follow-up control method between two servo systems according to claim 1 or 2, characterized in that the compensator is constituted by a PID controller.