JPH0767297B2 - Shaft vibration suppression control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to shaft vibration suppression for controlling shaft vibration of a control target including a shaft mechanically connecting an electric motor and a load machine, and a motor and a load machine. The present invention relates to a control device.

[Conventional technology]

FIG. 3 is a control block diagram showing a conventional shaft vibration suppression control device. In the figure, 1 is a first subtractor for obtaining a deviation between a speed reference signal N _ref and a speed feedback signal N _fb ,
2 speed controller which receives the first output signal ΔN of the subtractor 1, 3 addition for adding the current command correction signal .DELTA.i _sc correction gain circuit 10 to be described later and the output signal i _sc of the speed controller 2 , 4 is a current command limiter that receives the output signal i _a of the adder 3, 5 is a current controller that receives the output signal I of the current command limiter 4, and 6 is an output signal of the current controller 5. A controlled object including an electric motor to be controlled, a load, and an axis connecting the electric motor and the load is shown. 7 is the output signal i of the speed controller 2
_The current controller model with _sc as input, 8 is the controlled object model with the output signal of the current controller model 7 as input, 9 is the output signal ω _m of the controlled object model 8 and the speed feedback signal which is the output of the controlled object 6. A second subtractor for _obtaining a deviation from N _fb (ω _r ) and a correction gain circuit 10 that receives the output signal Δω of the second subtractor 9 and outputs a current command correction signal Δi _sc .

Next, the operation will be described.

The speed reference signal N _ref and the speed feedback signal N _fb
The first subtractor 1, the speed controller 2, the current command limiter 4, and the current controller 5 that determine the deviation from This is a commonly used method and will not be described here.

The output signal _isc of the speed controller 2 is added to the current controller model 7 simulating the current controller 5 for calculation to simulate the torque T applied to the actual controlled object 6 as an output signal.

Next, the control target model 8 is calculated by using the simulated output signal as an input, and the output signal (speed) of the rotation (rotation of the control target model 8) which is the calculation result of the control target model 8 is calculated.
Get ω _m .

Here, the controlled object model 8 is modeled as a model in which an electric motor and a load are directly coupled without going through a shaft, and is an ideal model without twist (shaft vibration) due to the shaft.

Therefore, the velocity ω _m obtained by the calculation of the controlled object model 8 is considered to be an ideal value.

Next, the deviation (output signal) Δω between the speed ω _m of the controlled object model 8 and the speed feedback signal (actual speed) ω _r is obtained by the second subtractor 9. This deviation Δω is the difference between the ideal speed ω _m and the actual speed ω _r, and is due to the influence of torsion of the shaft (shaft vibration) and the like.

Next, the correction gain circuit 10 obtains a current command correction signal Δi _sc necessary to correct the deviation Δω between the ideal speed ω _m and the actual speed ω _r caused by the shaft vibration or the like, and the current command correction signal .DELTA.i _sc the by connexion speed controller 2 outputs the signal to the adder 3 (current command) is added to i _sc.

Therefore, the shaft vibration of the controlled object 6 can be suppressed.

A shaft vibration suppression control device similar to the above-described shaft vibration suppression control device is disclosed in, for example, AE Icon'86 (IEEE IECON'86), pages 41 to 46, on a micro computer-based motor. Drive system with simulator hollowing control (A Micorcomputer-Based Motor Drive System wit
h Simulator Following Control).

[Problems to be solved by the invention]

Since the conventional shaft vibration suppression control device is configured as described above, as shown in FIG. 4, the load increases at time t ₀ ,
As shown in FIG. 4 (c) at time t ₁ , when the output signal (current command) i _a exceeds the current limit value of the current command limiter 4,
The output signal I of the current command limiter 4 is limited as shown in FIG. At this time, the output signal i of the speed controller 2
_sc (FIG. 4 (a)) tries to increase until the speed controller 2 becomes saturated (limit).

Therefore, since the controlled object model 8 is basically an integrator, the output signal ω _m increases as shown in FIG. 4 (e), and there is a problem when it diverges.

The present invention has been made to solve the above-mentioned problems, and even when the current command is limited by the current command limitation, the controlled object model does not diverge and the shaft vibration is stably operated. The purpose is to obtain a control device.

[Means for solving problems]

When the output signal of the adder exceeds the current command limit value, the shaft vibration suppression control device according to the present invention varies the phase and gain of the current command correction signal output from the correction gain circuit to change the model of the controlled object. A phase inversion / variable gain circuit that feeds back to the input side via the first switch, and a second switch that shuts off the current controller model and the controlled object model are provided.

[Action]

When the output signal of the adder exceeds the current command limit value, the shaft vibration suppression control device according to the present invention controls the current command correction signal by feeding back to the input side of the controlled object model through the phase inversion / variable gain circuit. The controlled object model is controlled so that the deviation between the speed of the object model and the actual speed becomes zero.

〔Example〕

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

In FIG. 1, 11 is a phase inversion / variable gain circuit that feeds back to the controlled object model 8 by inputting the current command correction signal Δi _sc of the correction gain circuit 10, and 12 is a correction gain circuit 10 and a phase inversion / variable gain circuit 11. A first switch connected between the current controller model 7 and the controlled object model 8 is indicated by reference numeral 13.

The first and second switches 12 and 13 are turned on and off by the current limit state signal LMT output from the current command limiter 4, but the states are opposite.

2 (a) to (g) are waveform charts showing the signals of FIG.

Next, the operation will be described.

When the output signal i _a of the adder 3 does not interfere with the current limit of the current command limiter 4, the operation is similar to the operation of the conventional example described above, and therefore the description is omitted and the output signal i _a is the current command limit. A case where the current limit value of the device 4 is violated will be described.

Until time t ₀ when the speed of the controlled object 6 is controlled to be constant by the speed controller 2, as shown in FIG. 2 (e), the output signal ω _{m of the} controlled object model 8 is equal to the load. Becomes higher than the speed feedback signal (actual speed) ω _{r, and} an output signal (deviation) Δω corresponding to the load is always generated from the first subtractor 9. This deviation Δω is output by the correction gain circuit 10 as a current command. It becomes the correction signal Δi _sc .

Therefore, as a result, the current command correction signal Δi _sc bears all the load current commands, and until the time t ₀ , as shown in FIG. 2 (a), the output signal of the speed controller 2 is output. i _sc
Is zero.

Next, when the load increases at time t ₀ , the output signal of the speed controller 2 is transiently changed by the output signal ΔN of the first subtractor 1.
i _sc increases (changes), and as a result, the output signal ω _m of the controlled object model 8 increases as shown in FIG. 2 (e). Therefore, as described above, the output signal Δ of the second subtractor 9 is
ω increases, and the current command correction signal Δi of the correction gain circuit 10
_{Since sc} increases, when the output signal i _a of the adder 3 conflicts with the current limit value of the current command limiter 4 at time t ₁ as shown in FIG. The current limit state signal LMT shown in FIG. 2 (g) is generated, and the first switch 12 is turned on and the second switch 13 is turned off by this current limit state signal LMT.

Therefore, the current command correction signal Δi of the correction gain circuit 10 is
_{The sc} is supplied to the phase inversion / variable gain circuit 11 and fed back to the input side of the controlled model 8.

Further, the current controller model 7 and the controlled object model 8 are cut off.

Since the above operation is performed when the current command is limited, the output signal ω _m of the controlled object model 8 is set as shown in FIG. 2 (e).
Operates with a time constant τ determined by the gain K of the phase inversion / variable gain circuit 11 so that the deviation between the actual speed ω _r and zero is zero. As a result, the current command correction signal Δi _sc becomes zero with the time constant τ, and the output signal _isc of the speed controller 2 increases. That is, until the time t ₁ required for the current command limitation,
As described above, the current command correction signal Δi _sc bears all the load, and thereafter, the output signal _isc bears all the load with the time constant τ.

Therefore, the output signal ω _m of the controlled object model 8 does not diverge even when the current command is limited.

The switching of the load sharing can be performed in a shockless manner by adjusting the gain K of the phase inversion / variable gain circuit 11.

〔The invention's effect〕

As described above, according to the present invention, when the output signal of the adder exceeds the current command limit value, the current command correction signal output from the correction gain circuit is phase-inverted and the gain is changed to input the control target model. Since the phase inversion / variable gain that feeds back to the side via the first switch and the second switch that cuts off the current controller model and the controlled object model are provided, the output of the speed controller when the current command is limited It is possible to smoothly switch the load sharing between the signal and the current command correction signal of the correction gain circuit.

Further, there is an effect that the output signal of the controlled object model does not diverge.

[Brief description of drawings]

FIG. 1 is a block diagram showing a shaft vibration suppressing control apparatus according to an embodiment of the present invention, FIGS. 2 (a) to 2 (g) are waveform diagrams showing respective signals of FIG. 1, and FIG. 3 is a conventional shaft. Block diagrams showing the vibration suppression control device, and FIGS. 4 (a) to 4 (f) are waveform diagrams showing the signals of FIG. In the figure, 1 is a first subtractor, 2 is a speed controller, 3 is an adder, 4 is a current command limiter, 5 is a current controller, 6 is a control target, 7 is a current controller model, and 8 is control. Object model,
9 is a second subtractor, 10 is a correction gain circuit, 11 is a phase inversion / variable gain circuit, 12 is a first switch, and 13 is a second switch. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A first subtractor for calculating a deviation between a speed reference signal and a speed feedback signal from a controlled object, a speed controller having an output signal of the first subtractor as an input, and the speed control. Adder for adding the output signal of the converter and the current command correction signal, a current command limiter for limiting the current command of the output signal of the adder, and outputting a current limit state signal in the current limit state, and the current A current controller that controls the current flowing from the command limiter to the controlled object, a current controller model that simulates the current controller by the output signal of the speed controller, and the control by the output signal of this current controller model A controlled object model simulating the object, a second arithmetic unit for obtaining a deviation between the output signal of the controlled object model and the speed feedback signal, and an output signal of the second arithmetic unit are used as the electric signal. In shaft vibration suppression control apparatus having a correction gain circuit for converting the command correction signal, phase inversion and that feedback by varying the phase inversion and gain the current command correction signal to the input side of the controlled object model
If the output signal of the variable gain circuit and the adder is greater than or equal to the current limit value of the current command limiter, it is closed by the current limit status signal generated from this current command limiter, and open if it is less than the current limit value. The first switch that opens and closes the input path of the phase inversion / variable gain circuit, and the first switch that is opposite to the first switch according to the current limit state signal.
Vibration suppression, characterized in that it has a second switch that opens when the switch of (1) closes and closes when the first switch opens and opens and closes the output path of the current controller model. Control device.