JPH0576193A - Motor controller - Google Patents

Abstract

(57) [Summary] According to the present invention, in a motor control device for controlling a motor for driving a load whose inertia moment changes, the speed of the motor is detected, and the inertia of the load is detected based on the detected value. Estimating means for estimating the moment, and a correcting means for calculating the amount of change in the moment of inertia of the load based on the estimated value of the estimating means and correcting the control amount according to the calculated value are provided. The frequency response is controlled to be constant even when the inertia moment of the load changes. [Effect] According to the present invention, the control amount is corrected according to the changing load inertia moment, so that a constant frequency response is always obtained It is possible to realize highly accurate and accurate motor control.

Description

Detailed Description of the Invention

 [Object of the Invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control device capable of obtaining a constant frequency response to a change in load inertia moment.

[0002]

2. Description of the Related Art Generally, in the case of proportional-plus-integral control, a motor control device also changes its frequency response with respect to changes in the moment of inertia of the load.

An outline of a conventional electric motor control device will be described below with reference to FIG. A deviation between the speed command V _REF and the speed feedback V _FBK is calculated by the adder 1, the calculated deviation is integrated by the integrator 2, and the current command I is proportionally calculated by the proportional device 3.
Output _REF . Torque constant T is _added to this current command I _REF.
The multiplier 4 multiplies _CON to output the torque T. This torque T is divided by a divider 5 into an inertia moment J _{M of the} electric motor (not shown) and a moment of inertia J _{L of the} load (not shown).
Divide by the sum of. Then, this divided value becomes the speed, which is fed back and becomes the speed feedback V _FBK . In this way, the proportional and integral constants of proportional-plus-integral control are fixed.

[0004]

In the motor control device as described above, when the moment of inertia of the load changes, for example, when the speed of the drive shaft of the winder is controlled, the load is controlled. The moment of inertia increases every moment and the frequency response deteriorates. Therefore, an object of the present invention is to provide a motor control device that can obtain a constant frequency response even if the moment of inertia of the load changes. [Constitution of Invention]

[0005]

In order to achieve the above object, the present invention detects the speed of the electric motor in a motor control device for controlling an electric motor for driving a load whose inertia moment changes, and detects the detected value. Based on the estimation means for estimating the moment of inertia of the load, and based on the estimated value of this estimation means, the change amount of the moment of inertia of the load is calculated, and the control amount is corrected according to the calculated value. There is provided a motor control device that includes a correction unit that controls the frequency response to be constant even when the inertia moment of the load changes.

[0006]

In the electric motor control device of the present invention configured as described above, the inertia of the load is kept constant by always keeping a value obtained by dividing an arbitrary controlled variable by the sum of the moment of inertia of the load and the moment of inertia of the electric motor. Speed control can be performed in which the frequency response does not change even if the moment changes.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the deviation between the speed command V _REF and the speed feedback V _FBK is calculated by an adder 1, the calculated deviation is integrated by an integrator 2, and proportional by a proportionalizer 3, Outputs the command I _REF . This current command I _REF is multiplied by the torque constant T _CON in the multiplier 4 to output the torque T. A value obtained by dividing the torque T by the sum of the inertia moment J _{M of the} electric motor (not shown) and the inertia moment J _L of the load (not shown) by the divider 5 becomes the speed feedback V _FBK . The load inertia moment estimator 10 (not shown) estimates the load inertia moment J _L from the speed feedback V _FBK , and the motor inertia moment J
A signal proportional to the change in the sum of _M and the load inertia moment J _L is output. The proportional setting device 11 sets in the proportional device 3 a proportional constant proportional to the signal output from the load inertia moment estimator 10. Next, load inertia moment J
_{The L} estimation method will be described with reference to FIG.

As shown in FIG. 2, radius A [m] and length L
At the core 20 of the solid cylindrical winding at [m], the thickness h [m],
The moment of inertia J of the load after T [sec] when the pulp 21 having the width L [m] is wound at the speed N [rpm]
_{Find L.} When the pulp 21 is wound from the shaft to R [m], the relationship between the speed N and the radius R is

[0010]

[Equation 1] Is expressed as The load inertia moment J _L is R

[0011]

[Equation 2] Is expressed as Where δ and δ ₀ are specific gravity [kg
/ M ³ ]. Therefore, the load inertia moment J _L is a function of time T and speed N.

Thus, when the time for sampling the velocity feedback V _FBK is known in advance, the load inertia moment J _L can be obtained from the velocity feedback V _FBK .

According to the present embodiment configured as described above, as shown in FIG. 3, the frequency response gain G _P / (J _M + J _L ) shown in FIG. Then, the frequency response from point A to point B shown in FIG. 1 does not change. In FIG. 3, K _t represents a torque constant.

[0014]

As described above, according to the motor control device of the present invention, the control amount is corrected according to the changing moment of inertia of the load, so that a constant frequency response is always obtained and the reliability is high. It is possible to realize accurate motor control.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram illustrating a method for estimating a load inertial moment according to an embodiment of the present invention.

FIG. 3 is a diagram showing a frequency response according to an embodiment of the present invention.

FIG. 4 is a schematic block diagram showing a conventional electric motor control device.

[Explanation of symbols]

 10 ... Moment of inertia estimator 11 ... Proportional setting device

Claims (1)

[Claims] 1. An electric motor control device for controlling an electric motor that drives a load whose inertia moment changes, and an estimating means for detecting the speed of the electric motor and estimating the moment of inertia of the load based on the detected value. Based on the estimated value of the estimation means, the change amount of the inertia moment of the load is calculated, and a correction means for correcting the control amount is provided according to the calculated value, and the inertia moment of the load changes. Is a motor control device characterized in that the frequency response is controlled to be constant.