JP2005304132A - Motor controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a motor controller which can reduce an influence caused by the disturbance of motor thrust without changing the property of a velocity control loop. <P>SOLUTION: This motor controller, which is equipped with a position control loop for feedback-controlling the position of a moving element of a motor and a velocity control loop which feedback-controls the travel speed of the moving element of the motor, is provided with an acceleration control loop for feedback-controlling the travel acceleration of the moving element of the motor, and a signal path for giving an acceleration command value outputted by the velocity control loop to the acceleration control loop as a feed forward signal. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a motor control device including a position control loop that feedback-controls the position of a motor slider and a speed control loop that feedback-controls the moving speed of the motor slider. More specifically, the present invention relates to a motor control device devised for reducing the influence of thrust disturbance due to cogging, ripple, etc. of the motor.

FIG. 3 is a diagram showing a configuration example of a conventional motor control device.
In FIG. 3, the motor 10 is a linear motor, a planar motor in which a moving element moves in a two-dimensional direction, a rotary motor, or the like.
The sensor 11 detects the movement of the mover of the motor 10. In this case, the mover corresponds to a rotor in the case of a rotary motor. The sensor 11 is, for example, an optical encoder, a magnetic resolver, a magnetostrictive sensor, or the like.

The position control unit 12 outputs a control signal for feedback control of the position of the moving element of the motor 10 based on the deviation between the position command value and the position detection value of the sensor 11. This control signal is a speed command value signal.
The speed converter 13 converts the detection signal of the sensor 11 into a speed detection signal. The speed converter 13 is an F / V converter, for example.

The speed control unit 14 outputs a control signal for feedback control of the moving speed of the moving element of the motor 10 based on the deviation between the speed command value from the position control unit 12 and the detected speed value from the speed converter 13. To do.
The drive circuit 15 drives the motor 10 based on a control signal from the speed control unit 14. The drive circuit 10 includes a PWM circuit that generates a pulse width modulation signal (PWM signal) for controlling the excitation current of the motor coil, a bridge-type inverter circuit that drives the motor based on the PWM signal, and the like. Yes.

FIG. 4 is a block diagram of the motor control device of FIG. FIG. 4 shows a block diagram of the speed control loop.
In FIG. 4, the gain of the speed error amplifier is G (s). The speed error amplifier is in the speed control unit 14 and amplifies the deviation between the speed command value and the speed detection value from the speed converter 13.
The gain of the thrust generator is Kf. The thrust generator is a part such as the PWM circuit, the inverter circuit, or the motor described above.
A thrust disturbance ΔF is generated by thrust due to cogging of the motor, thrust ripple, and the like. The actual thrust is F.

The gain of the load is 1 / M (M is mass). The load is an inertia of the motor itself, a load connected to the motor, or the like.
From the acceleration α, the velocity v is v = α / S (S is a Laplace operator). Therefore, the gain for converting acceleration into velocity is 1 / S.
The speed detection sensitivity of the sensor 11 is Kvel.
A deviation between the speed detection value VEL output from the sensor 11 and the speed command value Vin is given to the speed error amplifier. Based on the amplified error, speed feedback control of the motor 10 is performed.

  Cited Document 1 describes a motor control device provided with a position feedback control unit and a speed feedback control unit.

Japanese Patent Laid-Open No. 2002-171782

  In the conventional example in which the gain is as shown in FIG. 4, unless the gain G (s) of the speed error amplifier is sufficiently increased, the fluctuation ΔVEL occurs in the speed detection value VEL due to the above-described thrust disturbance ΔF. However, when the gain G (s) is increased, there is a problem that oscillation occurs when the signal delay in the loop is large or when there is mechanical resonance in the motor.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to realize a motor control device that can reduce the influence of disturbance of the motor thrust without changing the characteristics of the speed control loop.

  In order to achieve such a subject, the present invention is configured as follows.

(1) In a motor control device including a position control loop that feedback-controls the position of the moving element of the motor and a speed control loop that feedback-controls the moving speed of the moving element of the motor.
An acceleration control loop that feedback-controls the moving acceleration of a moving element of a motor is provided, and a signal path that provides an acceleration command value output from the speed control loop as a feedforward signal to the acceleration control loop is provided. Control device.

(2) The speed control loop is provided with a speed error amplifier that amplifies a deviation between a speed command value and a speed detection value of the motor moving element, and the acceleration control loop has an acceleration command value and an acceleration detection value of the motor moving element. The motor control device according to (1), further comprising an acceleration error amplifier that amplifies a deviation of the acceleration error amplifier, wherein the speed error amplifier bypasses the acceleration error amplifier and provides an acceleration command value to the acceleration control loop.

(3) The motor control device according to (2), wherein a loop gain of the acceleration control loop excluding the acceleration error amplifier is set to be 1.

(4) The motor control device according to (2), wherein the acceleration error amplifier is an integral type error amplifier.

As is apparent from the above description, the present invention has the following effects.
An acceleration control loop is provided, and the acceleration command value of the speed control loop is given to the acceleration control loop as a feedforward signal. At this time, by adjusting a gain (acceleration constant) when converting acceleration into speed, the influence of disturbance thrust can be reduced, and the characteristics of the speed control loop can be set so as not to be affected by the acceleration control loop. As a result, it is possible to reduce the influence of disturbance of the thrust of the motor caused by cogging thrust, thrust ripple, etc., without changing the characteristics of the speed control loop.

Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, the same reference numerals are assigned to the same parts as those in the previous figure.
In the motor control device shown in FIG. 1, an acceleration control loop is provided in addition to the position control loop and the speed control loop.

The acceleration sensor 20 detects the acceleration of the moving element of the motor 10. The control signal output from the speed control unit 14 is an acceleration command value signal.
The acceleration control unit 21 outputs a control signal for feedback control of the moving acceleration of the moving element of the motor 10 based on the deviation between the acceleration command value from the speed control unit 14 and the detected acceleration value from the acceleration sensor 20. . This control signal is given to the drive circuit 15.
A signal path through which the acceleration command value output from the speed control unit 14 bypasses the acceleration control unit 21 is provided. The bypassed acceleration command value is added to the output of the acceleration control unit 21 as a feed forward signal. Thereby, the acceleration is feedforward controlled.

FIG. 2 is a block diagram of the motor control device of FIG. FIG. 2 shows a block diagram of the speed control loop and the acceleration control loop.
In FIG. 2, the gain of the speed error amplifier is Gvel (s).
The gain of the acceleration error amplifier is Gacc (s). The acceleration error amplifier is in the acceleration control unit 21 and amplifies a deviation between the acceleration command value and the acceleration detection value of the acceleration sensor 20. The acceleration error amplifier is, for example, an integral type error amplifier.
The acceleration detection sensitivity of the acceleration sensor 20 is Kα.

The acceleration command value Accd of the speed error amplifier is added to the output of the acceleration error amplifier, bypassing the acceleration error amplifier. Thus, a signal path for feedforward control of the acceleration is provided.
The acceleration constant Ka is a gain of a circuit that generates an acceleration control signal.

となり、速度指令Ｖｉｎに対する応答には加速度誤差増幅器のゲインＧａｃｃ（ｓ）は影響しないが、外乱推力に対しては１／｛１＋Ｇａｃｃ（ｓ）｝に減衰させることができる。
このようにゲインを設定すると、加速度制御ループで、加速度誤差増幅器を除く部分のループゲインは１になる。 In the control loop of FIG.
Ka = M / (Kα · Kf)
Then, the closed loop characteristic of speed is

Thus, the response to the speed command Vin is not affected by the gain Gacc (s) of the acceleration error amplifier, but the disturbance thrust can be attenuated to 1 / {1 + Gacc (s)}.
When the gain is set in this way, the loop gain of the portion excluding the acceleration error amplifier in the acceleration control loop becomes 1.

It is a block diagram which shows one Example of this invention. It is a block diagram of the control apparatus of the motor of FIG. It is the figure which showed the structural example of the conventional motor control apparatus. It is a block diagram of the control apparatus of the motor of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Motor 11 Sensor 12 Position control part 13 Speed converter 14 Speed control part 15 Drive circuit 20 Acceleration sensor 21 Acceleration control part

Claims (4)

In a motor control device comprising a position control loop for feedback control of the position of the motor mover and a speed control loop for feedback control of the moving speed of the motor mover,
An acceleration control loop that feedback-controls the moving acceleration of a moving element of a motor is provided, and a signal path that provides an acceleration command value output from the speed control loop as a feedforward signal to the acceleration control loop is provided. Control device.   The speed control loop is provided with a speed error amplifier that amplifies the deviation between the speed command value and the detected speed value of the motor moving element, and the acceleration control loop is provided with a deviation between the acceleration command value and the detected acceleration value of the motor moving element. 2. The motor control device according to claim 1, further comprising an acceleration error amplifier for amplifying, wherein the speed error amplifier bypasses the acceleration error amplifier and provides an acceleration command value to the acceleration control loop.   3. The motor control device according to claim 2, wherein a loop gain of the acceleration control loop excluding the acceleration error amplifier is set to be 1. 3. The motor control apparatus according to claim 2, wherein the acceleration error amplifier is an integral type error amplifier.

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