JP3240778B2 - Motor speed control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed control device for a motor used in OA equipment or audio and video equipment.

[0002]

2. Description of the Related Art In recent years, in a recording / reproducing apparatus of an OA apparatus and the like, as the density of media increases, high-precision motor speed control is also required.

A conventional motor speed control device will be described below. FIG. 3 shows a conventional motor speed control device. In FIG. 3, reference numeral 1 denotes a motor consisting of a rotating permanent magnet magnetized with multiple poles and an armature, 2 a drive circuit, 3 a frequency generator, 4 a speed error detection circuit, and 5 a speed control circuit.

The operation of the motor speed control device configured as described above will be described below. A rotation cycle signal of the motor detected by the frequency generator 3 is compared with a target cycle by a speed error detection circuit 4 to output a speed error signal. The speed control circuit 5 outputs a torque signal to the drive circuit 2 so as to eliminate the speed error signal.
Drives the motor 1 according to the torque signal, and rotates the motor 1 at a substantially constant speed.

[0005]

However, in the above configuration, the speed is reduced by the cogging torque generated with respect to the magnetic poles of the permanent magnet of the motor and the salient poles of the armature core and the torque ripple generated in proportion to the current flowing through the motor. There is a problem that the cogging torque and the torque ripple are added to the torque by the control, and the rotational speed becomes uneven.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a motor speed control device which is free from uneven rotation due to cogging torque.

[0007]

In order to achieve this object, a motor speed control apparatus according to the present invention comprises: a motor comprising a multi-pole magnetized permanent magnet and an armature; Driving means for driving, a rotation state detector for detecting a state corresponding to a rotation speed or a rotation cycle of the motor, and a speed error for outputting an error signal with respect to a target rotation speed or a target rotation cycle from an output of the rotation state detector A detection circuit, a speed control circuit that outputs a torque command so as to make an error signal of the speed error detection circuit zero, a rotation position detector that detects a rotation position serving as a base point of one rotation of the motor, A first torque pattern generation circuit that outputs a torque signal of a predetermined fluctuation pattern for one rotation of the motor in synchronization with the output of the rotation state detector with the output of the position detector as a base point ; Similarly to the first torque pattern generation circuit, a second torque for outputting a signal of a predetermined fluctuation pattern for one rotation of the motor in synchronization with the output of the rotation state detector with the output of the rotation position detector as a base point. A pattern generation circuit, a current value detection circuit that calculates a current value flowing to the motor from a torque signal of the speed control circuit, and a multiplication circuit that multiplies an output of the second torque pattern generation circuit by an output of the current value detection circuit. And an addition circuit that adds a composite signal of the output of the speed control circuit, the output of the first torque pattern generation circuit, and the output of the multiplication circuit, and outputs the resultant signal to driving means.

[0008]

With this configuration, the cogging torque is canceled.
Generates the first torque pattern for one motor rotation pattern
Circuit for one rotation of motor to cancel torque ripple in circuit
In advance in the second torque pattern generation circuit,
Synchronized with the rotation status detector based on the output of the shift position detector
By adding a torque signal for canceling the cogging torque to the drive signal of the conventional speed control device and a torque signal for canceling the torque ripple generated in proportion to the current flowing to the motor, the cogging torque and the torque ripple are obtained. Thus, it is possible to realize a motor speed control device having no rotation unevenness caused by the above.

[0009]

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

In FIG. 1, reference numeral 1 denotes a motor consisting of a multi-pole magnetized rotating permanent magnet and an armature, 2 a drive circuit, 3 a frequency generator, 4 a speed error detection circuit, 5 a speed control circuit, and 6 Is a position detector, 7 is a first torque pattern generation circuit, 8 is a second torque pattern generation circuit, 9 is a current value detection circuit, 10 is a multiplication circuit, and 11 is an addition circuit.

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

In FIG. 2, A is an output signal of the position detector 6, B is an output signal of the frequency generator 3, and C is an adder circuit 11.
Is a torque generated in the motor 1.

First, a rotation cycle signal B of the motor detected by the frequency generator 3 is compared with a target rotation cycle by a speed error detection circuit 4 and an error signal is output. The speed control circuit 5 outputs a torque signal so that the error signal of the speed error detection circuit 4 becomes zero. On the other hand, the rotational position detector 6 detects the rotational position of the motor 1 and outputs a position signal A once per rotation. The first torque pattern generation circuit 7 outputs a predetermined pattern of one rotation of the motor in synchronization with the output of the position signal A of the rotation position detector 6 and the rotation cycle signal B of the frequency generator 3. Also, the second torque pattern generation circuit 8 outputs a signal of a predetermined pattern of one rotation of the motor to the multiplication circuit 10 in synchronization with the output of the rotation position detector 6 and the frequency generator 3, and the current value detection circuit 9 The current flowing through the motor 1 is calculated from the torque signal of the speed control circuit 5 and output to the multiplication circuit 10. The multiplication circuit 10 multiplies the output of the second torque pattern generation circuit 8 and the output of the current value detection circuit 9 to output a torque signal. I do. The addition circuit 11 adds the torque signals of the speed control circuit 5, the first torque pattern generation circuit 7, and the multiplication circuit 10 and outputs a torque signal C to the drive circuit 2, and the drive circuit 2 Is output to the motor 1 for driving the
The motor 1 generates a torque according to the drive signal and a torque ripple and a cogging torque proportional to the magnitude of the current flowing through the motor. At this time, the cogging torque of the motor 1 is canceled by setting the output pattern of the first torque pattern generation circuit 7 to cancel the cogging torque, and the output pattern of the second torque pattern generation circuit 8 is changed to a torque ripple. By setting to cancel, the torque ripple of the motor 1 is canceled, and only the torque signal of the speed control circuit 5 is generated as the torque D of the motor 1. As is apparent from this, the motor speed control apparatus according to the present embodiment has an effect that the cogging torque and the torque ripple do not affect the speed control.

As described above, according to this embodiment, the torque of the multiplication circuit 10 for multiplying the output of the second torque pattern generation circuit 8 and the output of the current value detection circuit 9 by the torque signal of the first torque pattern generation circuit 7 is used. By synthesizing the signal and the torque signal of the speed control circuit 5, the cogging torque generated with respect to the magnetic poles of the permanent magnets of the motor 1 and the salient poles of the armature core and uneven rotation due to torque ripple generated in proportion to the motor current are eliminated. be able to.

[0015]

As described above, according to the present invention, the motor speed control device outputs a torque signal of a predetermined pattern for one rotation of the motor in synchronization with the outputs of the rotation state detector and the rotation position detector. A torque pattern generation circuit, an output of a second torque pattern generation circuit for outputting a signal of a predetermined pattern for one rotation of the motor in synchronization with outputs of the rotation state detector and the rotation position detector, and a speed control circuit An excellent motor speed control device that has a multiplication circuit that multiplies an output of a current value detection circuit that calculates a current value from an output of the motor and outputs a torque signal, so that there is no uneven rotation speed of the motor caused by cogging torque and torque ripple. Can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a motor speed control device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of each output signal in the embodiment.

FIG. 3 is a block diagram showing a configuration of a conventional motor speed control device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 motor 2 drive circuit 3 frequency generator 4 error detection circuit 5 speed control circuit 6 position detector 7 first torque pattern generation circuit 8 second torque pattern generation circuit 9 current value detection circuit 10 multiplication circuit 11 addition circuit A position Signal B Rotation cycle signal C Torque signal D Torque

Claims (1)

(57) [Claims] 1. A motor consisting of a multi-pole magnetized permanent magnet and an armature, a driving means for driving the motor in accordance with an input signal, and detecting a state corresponding to a rotation speed or a rotation cycle of the motor. A rotation state detector, a speed error detection circuit that outputs an error signal with respect to a target rotation speed or a target rotation cycle from the output of the rotation state detector, and a torque command to set the error signal of the speed error detection circuit to zero. The output speed control circuit and the base point for one rotation of the motor.
That a rotational position detector for detecting a rotational position, first for outputting a torque signal having a predetermined pattern of variation in synchronism of the motor one rotation to the output of the rotation state detector an output of the rotational position detector as a base point And a signal of a predetermined fluctuation pattern for one rotation of the motor in synchronization with the output of the rotation state detector based on the output of the rotation position detector as in the case of the first torque pattern generation circuit. A second torque pattern generation circuit that outputs a current value, a current value detection circuit that calculates a current value flowing to a motor from a torque signal of the speed control circuit, an output of the second torque pattern generation circuit, and the current value detection circuit. A multiplying circuit that multiplies the output of the first control unit, a combined signal of the output of the speed control circuit, the output of the first torque pattern generation circuit, and the output of the multiplication circuit, and outputs the result to the driving unit. Speed control device provided with an adding circuit to perform the operation.