JPH02241382A - Controller for motor - Google Patents

Abstract

PURPOSE:To shorten a time until an integrated value of an integrator becomes a steady value by setting an initial value most adapted to effectively form the integrator with an initial value setter at the time of transient response of a motor. CONSTITUTION:A rotating period of a motor 1 is converted to a period signal proportional to a rotating period by a rotation detector 2, and a period error signal becomes an error between the rotating period of the motor 1 and a target period. An integrator 5 integrates the period error signal, outputs its result, and an initial value setter 4 sets an initial value most adapted for effectively operating the integrator 5 in a transient state at the time of change of a target period if the target period is varied or variation in a disturbance upon target period change is predicted. Thus, since the time until the integrated value becomes a steady value is almost eliminated, responding characteristic can be improved without altering the steady characteristic of the motor 1.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a video tape recorder (hereinafter abbreviated as VTR).
The present invention relates to a motor control device used in a digital audio tape recorder (hereinafter abbreviated as DAT) and the like.

Conventional technology In recent years, in motor control circuits used in VTRs and DATs, in order to improve wow and flutter caused by load fluctuations, an integrator circuit is inserted into the feedback loop to increase the feedback gain in the low frequency region. has been taken. (For example, Actual Use of Servo Equipment, edited by Nobutoshi Kimura, Sanpo Publishing, pages 135-145).

Problems to be Solved by the Invention However, although the steady-state characteristics of the motor can be improved with the above configuration, the integration effect has a negative effect during transient response of the motor, and the time it takes for the data after integration to reach a steady value is difficult to compare. Since the target speed is long, there is a problem in that the time required for the motor to reach the target speed is delayed.

In view of the above problems, the present invention provides a motor control device that shortens the time required to reach a target speed without deteriorating the control characteristics of a motor subjected to integral compensation.

Means for Solving the Problems In order to solve the above problems, a motor control device of the present invention includes a motor, a rotation detector that outputs a period signal proportional to the rotation period of the motor, and a period signal and a target period. A speed error detection circuit that outputs the error as a periodic error signal, an integrating circuit that can set an initial value for integrating the periodic error signal, an initial value setting circuit that sets the initial value of the integrating circuit, and a periodic signal and integrating circuit. The adder circuit includes an adder circuit that adds the output of the adder and outputs the resultant output, and a drive circuit that drives the motor in accordance with the output of the adder circuit.

Effect of the Invention With the above-described configuration, the present invention allows the integral value of the integral circuit to become a steady value by setting the most suitable initial value for the integral circuit to function effectively during a transient response of the motor by using the initial value setting circuit. The time required to reach the target speed can be shortened, the time required to reach the target speed can be shortened, and the response characteristics of the motor can be improved.

Embodiment Hereinafter, a motor control device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a motor control device according to an embodiment of the present invention. In FIG. 1, 1 is a motor, 2 is a rotation detector, 3 is a speed error detection circuit, 4 is an initial value setting circuit, 5 is an integration circuit, 6 is an addition circuit, and 7 is a drive circuit.

The operation of the motor control circuit configured as described above will now be described with reference to FIG.

The rotation period of the motor 1 is converted by a rotation detector 2 into a period signal proportional to the rotation period. The speed error detection circuit 3 detects an error between the period of the periodic signal output from the rotation detector 2 and a predetermined period, and outputs it as a periodic error signal. Therefore, the period error signal is the error between the rotation period of the motor 1 and the target period. Integrating circuit 5 integrates the periodic error signal and outputs the result. The initial value setting circuit 4 is
If a change in the target period or a change in the disturbance associated with it is predicted, set the most suitable initial value for the integrator circuit so that it will work effectively in the transient state when the change in the target period occurs. . The adding circuit 6 adds the periodic error signal and the output of the integrating circuit and outputs the sum. The drive circuit 7 receives the output of the adder circuit 6 and drives the motor 1 according to the output.

In this way, by setting the initial value of the integrating circuit 5 according to the change in the target cycle of the motor 1 using the initial value setting circuit 4, the time required for the integral value to reach a steady value, which was a problem in the conventional example, can be reduced. Since this phenomenon is almost eliminated, the steady-state characteristics of the motor 1 are not changed (response characteristics can be improved).

FIG. 2 is a block diagram in the second embodiment. Components having the same functions as those in FIG. 1 are given the same numbers and their explanations will be omitted.

31 is a reference signal generation circuit, 32 is a reference signal generation circuit 31
33 is a target value generation circuit that outputs a target value of the periodic signal; 34 is a target value generation circuit 33 that receives the output of the timing signal generation circuit 32; 35 is an error signal latch circuit that receives the output of the timing signal generation circuit 32 and latches the output of the counter circuit 34.

The speed error detection circuit 3 includes a reference signal generation circuit 31°, a timing signal generation circuit 32. Target value generation circuit 33, counter circuit 34. It is composed of an error signal latch circuit 35.

51 is an adder circuit; 53 is an integral value latch circuit that latches the output of the adder circuit 51; 52 is an integral time generator circuit that outputs a latch timing signal of the integral value latch circuit 53;
4 is the output of the initial value setting circuit 4 and the integral value latch circuit 53
a selection circuit that selects and outputs either one of the outputs; 55;
is a multiplication circuit. The output of the selection circuit 54 is sent to the addition circuit 51
The signal is fed back to the error signal latch circuit 35 and added to the output of the error signal latch circuit 35 to form a closed loop configuration.

The integrating circuit 5 includes an adding circuit 51 . Integral time generation circuit 52.
It is composed of an integral value latch circuit 539, a selection circuit 54, and a multiplication circuit 55.

FIG. 3 is an operation waveform diagram showing the operation of the speed error detection circuit 3 of FIG. 2. In Fig. 3, the horizontal axis shows time and the vertical axis shows the magnitude of the signal, and the waveform.

E shows a digital quantity converted into an analog quantity. Hereinafter, the operation of the embodiment shown in FIG. 2 will be explained using FIG. 3.

The rotation period of the motor 1 is detected by a rotation detector 2 and output as a periodic signal proportional to the rotation period. The periodic signal is shown at A in FIG. The timing signal generation circuit 32 that has received the periodic signal outputs the timing signals shown in B and C in FIG. 3 based on the output of the reference signal generation circuit 31. The error signal latch circuit 35 receives the output of the timing signal generation circuit 32 (B in FIG. 3), latches the count value of the counter circuit 34, and outputs it as a periodic error signal. The periodic error signal is shown at E in FIG. The counter circuit 34 performs a counting operation upon receiving the output of the reference signal generation circuit 31, and after receiving the output of the error signal latch circuit, the target value generation circuit 33 receives the output of the timing signal generation circuit 32 (C in FIG. 3). Load the output of . The counting operation of the counter circuit 34 is shown in FIG. 3D.

In the integrating circuit 5, the periodic error signal which is the output of the speed error detection circuit 3 and the output of the selection circuit 54 are added together in the adding circuit 51 and outputted to the integral value latch circuit 53. The integral value latch circuit 53 receives a constant cycle latch signal output from the integral time generating circuit 52 and outputs the calculation result of the adder circuit 51. The selection circuit 54 normally outputs the output of the integral value latch circuit 53, but when changing the target rotation speed of the motor 1, the selection circuit 54 integrates the value corresponding to the change in the target rotation period from the initial value setting circuit 4 as an initial value. The output of the initial value setting circuit 4 is selected and output in order to be taken into the circuit 5.

The multiplication circuit 55 multiplies the output of the selection circuit 54 by a constant and outputs the result as the output of the integration circuit 5.

In this way, when a change in the target period and an accompanying change in disturbance are predicted, the most suitable initial value for the integration circuit 5 to function effectively in the transient state when the change in the target period occurs is determined. Set by the initial value setting circuit 4.

The periodic error signal E and the output of the integrating circuit 5 are added together by an adding circuit 6 and transmitted to a driving circuit 7. The drive circuit 7 drives the motor 1 according to the input signal.

As described above, the initial value setting circuit 4. By providing the integrating circuit 5, it is possible to set the initial value of the integrating circuit 5 suitable for the transient state of the motor 1, and there is almost no time required for the integral value of the integrating circuit 5 to reach a steady value. Therefore, the time required for the motor 1 to reach the target rotational speed is shortened, and the transient characteristics of the motor 1 are improved without changing the steady-state characteristics.

Note that the initial value setting circuit 4. Integral circuit 5. The adder circuit 6 can also be implemented using a microcomputer, and the effects of the invention will remain the same.

Furthermore, the speed error detection circuit 3 may be configured to count the output of the rotation detector using a reference periodic signal and calculate the difference from the target value, and is not limited to the embodiment. In addition, in the integrating circuit 5, an integral value latch circuit 53 and a selection circuit 5
The same effect can be obtained even if the order of 4 is reversed, or even if a latch circuit is placed before the adder circuit 51 and the periodic error signal E is latched in response to the latch signal from the integral time generating circuit 52.

Furthermore, the multiplication circuit 55 can also be realized by bit shifting, and the effect of the invention remains unchanged.

Effects of the Invention As described above, the present invention provides a motor, a rotation detector that outputs a periodic signal proportional to the rotation period of the motor, and a speed error detection circuit that outputs an error between the periodic signal and a target period as a periodic error signal. and an integrator circuit that integrates the periodic error signal, an initial value setting circuit that sets the initial value of the integrator circuit, an adder circuit that adds the periodic error signal and the output of the integrator circuit, and a drive circuit that drives the motor. By setting the initial value of the integrating circuit according to the change in target rotational speed when the target rotational speed changes, the time until the integral value reaches a steady value can be shortened, and the control characteristics of the motor can be improved. It becomes possible to shorten the time required to reach the target rotation speed without causing deterioration.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a motor control device according to a first embodiment of the present invention, FIG. 2 is a block diagram of a motor control device specifically showing a second embodiment of the present invention, and FIG. 2 is an operation waveform diagram for explaining the operation of FIG. 2. FIG. 1...Motor, 2...Rotation detector, 3...
・Speed error detection circuit, 4...Initial value setting circuit,
5... Integrating circuit, 6... Adding circuit, 7.
...Drive circuit. Name of agent: Patent attorney Shigetaka Awano et al. 18th
Fig. Fig. 2 - Rotating skating y-fjA, Teppou Kuebu 4 Fig. □ Unexamined Japanese Patent Application

Claims (3)

[Claims] (1) A motor, a rotation detector that outputs a periodic signal according to the rotational speed of the motor, and outputs an error between an output period of the rotation detector and a target period of the rotation detector as a periodic error signal. a speed error detection circuit that integrates and outputs a periodic error signal that is an output of the speed error detection circuit, and is capable of setting an initial value; and an initial value setting circuit that sets the initial value of the integration circuit; It is characterized by comprising an adding circuit that adds and outputs a periodic error signal that is an output of a speed error detection circuit and an output of the integrating circuit, and a drive circuit that drives the motor according to the output of the adding circuit. A control device for a motor. (2) The speed error detection circuit consists of a reference periodic signal generation circuit that generates a constant periodic signal, a timing signal generation circuit that outputs a timing signal in response to the output of the rotation detector, and a timing signal generation circuit that generates a timing signal according to the target rotational speed of the motor. a target value generation circuit that outputs a value; an error signal latch circuit that receives the output of the timing signal generation circuit and outputs a periodic error signal that is an output of the speed error detection circuit; and the error signal latch circuit that outputs the periodic error signal that is the output of the speed error detection circuit. After outputting,
A counter circuit receives the output signal of the timing signal generation circuit, inputs the output of the target value generation circuit, counts the output of the reference period signal generation circuit, and outputs the result to the error signal latch circuit. 2. The motor control device according to claim 1. (3) The integration circuit includes an integration time generation circuit that generates a constant periodic signal, an integration value latch circuit that receives the periodic signal of the integration time generation circuit and outputs the input signal, and an integration value latch circuit that outputs the input signal after receiving the periodic signal of the integration time generation circuit. a selection circuit that selects and outputs either the output of the output or the output of the initial value setting circuit; an addition circuit that adds the output of the selection circuit and the periodic error signal and outputs the result to the integral value latch circuit; and an output of the selection circuit. 2. The motor control device according to claim 1, further comprising a multiplier circuit which multiplies the result by a constant and outputs the result.