CN101536305A - Motor control device, and its control method - Google Patents

Abstract

Provided are a motor control device, which can estimate an inertial moment highly precisely within a small working range and even in case the gradient of a low frequency is not fixed due to the influence of friction or control, and a control method for the device. The motor control device comprises a speed signal generating unit (2) for generating a speed signal from a position signal, and a current control unit (1) for controlling a motor current on the basis of a torque command. Further comprised are a test torque command generating unit (3) for generating a test torque command containing multiple frequency components, a frequency characteristic calculating unit (4) for calculating the frequency characteristics from a response of the speed signal to the test torque command, and a mechanical parameter calculating unit (6) for calculating a mechanical parameter from the frequency characteristics.

Description

Controller for motor and control method thereof

Technical field

The present invention relates to a kind of controller for motor of calculating mechanical model.

Background technology

When the moment of inertia of adjusting machinery, with the actual scope that drives to a certain degree of the action of prescribed model, the torque instruction and the speed of output were tried to achieve moment of inertia (patent documentation 1) according to this moment in the past.

In addition, also have plenty of according to the low frequency slope of frequency characteristic and try to achieve moment of inertia (patent documentation 2,3).

By utilizing the value of this moment of inertia, can adjust the parameter of controller for motor best, by being used in the feedforward controller that carries out vibration damping control or the model of observer mechanical property is improved.

Patent documentation 1: the spy of Japan opens flat 9-182479 communique

Patent documentation 2: the spy of Japan opens the 2002-304219 communique

Patent documentation 3: the spy of Japan opens the 2003-79174 communique

Summary of the invention

In existing mechanical model estimation device, for the situation of the prior art of patent documentation 1, because with the actual scope that drives to a certain degree of the action of prescribed model, so in the time can't guaranteeing the actuating range of machinery, existence can't be implemented the situation of adjusting and moving.In addition, in the prior art of patent documentation 2,3, owing to adopt the method for trying to achieve moment of inertia by the low frequency slope of frequency characteristic, so because of the influence low frequency slope of friction or control not fixedly the time, existence can't obtain the situation of enough precision of adjusting.

The present invention carries out in view of the above problems, and purpose is to provide a kind of controller for motor and control method thereof, even in less operation range, because of the influence low frequency slope of friction or control not fixedly the time, also can infer moment of inertia accurately.

In order to address the above problem, the present invention is following formation.

Scheme 1 described invention provides a kind of controller for motor, be to possess by the rate signal generating unit of position signalling formation speed signal and according to the controller for motor of the current control division of torque instruction control motor current, it is characterized in that, possess: test torque instruction generating unit generates the test torque instruction that comprises a plurality of frequency contents; Real machine frequency characteristic calculating part goes out the real machine frequency characteristic by the RESPONSE CALCULATION at the described rate signal of described test torque instruction; And Machinery Ministry, generate mechanical parameter by described real machine frequency characteristic.

Being characterized as of scheme 2 described inventions in scheme 1 described controller for motor, possesses: position control section, by position command and the instruction of described position signalling formation speed; And speed controlling portion, generate described torque instruction by described speed command and described rate signal.

Being characterized as of scheme 3 described inventions, in scheme 1 described controller for motor, described real machine frequency characteristic comprises resonance frequency and amplitude and antiresonant frequency and amplitude thereof.

Being characterized as of scheme 4 described inventions, in scheme 1 and 2 described controller for motor, the mechanical parameter generating unit makes total moment of inertia of two inertia formula models and damping coefficient minor variations repeatedly, make two inertia formula model frequency characteristics roughly consistent, described total moment of inertia and described damping coefficient are determined as parameter with the real machine frequency characteristic.

Being characterized as of scheme 5 described inventions is in scheme 4 described controller for motor, by the described two inertial system formula models of formula (1) expression, by the intermediate-frequency gain of formula (2) expression antiresonant frequency and resonance frequency.

(formula 1)

$G\left(s\right)\≡\frac{1}{\mathrm{Js}}\frac{{{\mathrm{\ω}}_H}^2(s^2+2{\mathrm{\ζ\ω}}_{L}s+{{\mathrm{\ω}}_L}^2)}{{{\mathrm{\ω}}_L}^2(s^2+2{\mathrm{\ζ\ω}}_{H}s+{{\mathrm{\ω}}_H}^2)}---\left(1\right)$

(formula 2)

$H\left(\mathrm{\ω}\right)=\left|G\left(\mathrm{j\ω}\right)\right|=20\log \left(\frac{{{\mathrm{\ω}}_H}^2\sqrt{{\mathrm{\ω}}^4-2{\mathrm{\ω}}^2{{\mathrm{\ω}}_L}^2+{{\mathrm{\ω}}_L}^4+4{\mathrm{\ζ}}^2{{\mathrm{\ω}}_L}^2{\mathrm{\ω}}^2}}{J{{\mathrm{\ω}}_L}^2\mathrm{\ω}\sqrt{{\mathrm{\ω}}^4-2{\mathrm{\ω}}^2{{\mathrm{\ω}}_H}^2+{{\mathrm{\ω}}_H}^4+4{\mathrm{\ζ}}^2{{\mathrm{\ω}}_H}^2{\mathrm{\ω}}^2}}\right)---\left(2\right)$

Here, J is total moment of inertia, ω _HBe resonance frequency, ω _LBe antiresonant frequency, ω is a test frequency, and ζ is a damping coefficient, and s is a Laplacian.

Being characterized as of scheme 6 described inventions, in scheme 5 described controller for motor, the antiresonant frequency of more described real machine frequency characteristic of mechanical parameter generating unit and described two inertial system formula model frequency characteristics is to the gain of the scope of resonance frequency, if the gain of described real machine frequency characteristic is bigger, then make the small increase of total moment of inertia of two inertial system formula models, if less then small minimizing proceeds to roughly till the unanimity repeatedly.

Being characterized as of scheme 7 described inventions, in scheme 6 described controller for motor, the size of described gain is determined by comparing antiresonant frequency to the gain area of resonance frequency.

Being characterized as of scheme 8 described inventions, in scheme 6 described controller for motor, the initial value of described total moment of inertia is formula (3).

(formula 3)

$J=\frac{2{{\mathrm{\&omega;}}_H}^2(3{\mathrm{\&omega;}}_L+{\mathrm{\&omega;}}_H)}{{\mathrm{<figure-callout\; id="1"\; label="e"\; filenames="A200780040459E00111.png,A200780040459E00121.png"\; state="\{\{state\}\}">e</figure-callout>}}^{\frac{1}{40}(Y_L+Y_H)}{{\mathrm{\&omega;}}_L}^2({\mathrm{\&omega;}}_L+{\mathrm{\&omega;}}_H)({\mathrm{\&omega;}}_L+3{\mathrm{\&omega;}}_H)}---\left(3\right)$

But, Y _LBe the db conversion gain of the antiresonant frequency of real machine frequency characteristic, Y _HIt is the db conversion gain of resonance frequency.

Being characterized as of scheme 9 described inventions, in scheme 6 described controller for motor, the initial value of described total moment of inertia is formula (5).

But, Y _MIt is the real machine frequency characteristic

The time gain.

Scheme 10 described inventions provide a kind of control method of controller for motor, be to possess by the rate signal generating unit of position signalling formation speed signal and according to the control method of the controller for motor of the current control division of torque instruction control motor current, it is characterized in that possessing: comprise the test torque instruction of a plurality of frequency contents and obtain the step of real machine frequency characteristic to current control division input; The step of more described real machine frequency characteristic and two inertial system formula model frequency characteristics; Total moment of inertia of small repeatedly correction and damping coefficient are so that the consistent step of gain of described real machine frequency characteristic and described two inertial system formula model frequency characteristics; And the step of roughly total moment of inertia and damping coefficient being determined as parameter after the unanimity in described gain.

According to scheme 1 described invention, a kind of controller for motor can be provided, when the frequency resolution result in using open loop adjusts moment of inertia, even, also can adjust accurately at the such object that descends of the frequency characteristic because of the influence low frequency region of viscous friction or controller.

According to scheme 2 described inventions, a kind of controller for motor can be provided, when the frequency resolution result in using the closed-loop structure of being controlled by controller adjusts moment of inertia, even, also can adjust accurately at the such object that descends of the frequency characteristic because of the influence low frequency region of viscous friction or controller.

According to scheme 3 to 9 described inventions, a kind of controller for motor can be provided, even in less operation range,, also can infer moment of inertia accurately because of the influence low frequency slope of friction or control not fixedly the time.

According to scheme 10 described inventions, a kind of control method of controller for motor can be provided, even in less operation range,, also can infer moment of inertia accurately because of the influence low frequency slope of friction or control not fixedly the time.

Description of drawings

Fig. 1 is the block diagram of expression formation of the present invention.

Fig. 2 is the block diagram of expression formation of the present invention.

Fig. 3 is the flow chart of expression method of the present invention.

Fig. 4 is the figure of expression curve-fitting method of the present invention.

Fig. 5 is the figure of expression based on the result that adjusts of existing method.

Fig. 6 is the figure of expression based on the result of adjusting of the present invention.

Symbol description

The 1-current control division; 2-rate signal generating unit; 3-test torque instruction generating unit; 4-frequency characteristic calculating part; 5-mechanical parameter calculating part; The 6-mechanical parameter; The 7-position control section; The 8-speed controlling portion; The 11-motor; The 12-position detector; 13-machinery; 21-measure and frequency response; The frequency response of 22-two inertial system models; 23-estimates starting point; 24-estimates end point; The frequency characteristic of 25-rigid system model.

Embodiment

Below, with reference to accompanying drawing specific embodiments of the invention are described.

Embodiment 1

Fig. 1 is the block diagram of the formation of expression the present invention the 1st embodiment.Among the figure, the 1st, current control division, the 2nd, rate signal generating unit, the 3rd, test torque instruction generating unit, the 4th, frequency characteristic calculating part, the 5th, mechanical model calculating part, the 6th, mechanical model, the 11st, motor, the 12nd, position detector, the 13rd, machinery.Current control division 1 converts torque instruction to current-order, and the current deviation of current-order and motor current is carried out PID control and treatment and formation voltage instruction, and voltage instruction is carried out pulse-width modulation (PWM) and driving power transducer to the motor supply capability.Rate signal generating unit 2 is obtained the time difference formation speed signal of the position signalling of the position detector that combines with motor.Test torque instruction generating unit 3 is not in common operation mode at controller for motor but generates the torque instruction that comprises a plurality of frequency contents during test pattern and to current control division 1 input.Rate signal when frequency characteristic calculating part instrumentation test torque instruction is input to current control division 1 also calculates frequency characteristic.Several candidates are extracted in the combination that mechanical model calculating part 5 is calculated resonance frequency, antiresonant frequency from the frequency of the Wave crest and wave trough of frequency characteristic out, differentiate and wish modeled 2 inertial systems.

The flow chart of expression the inventive method in Fig. 3.As shown in the figure, method of the present invention is handled by 7 steps of step 1～7.In step 1, will comprise the test torque instruction input current control part of a plurality of frequency contents, the response of instrumentation rate signal.In step 2, according to the frequency characteristic of the response computing machinery of the test torque instruction of input and the rate signal of instrumentation.In step 3,, carry out the detection of Wave crest and wave trough at the result of frequency characteristic computing.Reckoning is extracted several candidates out as the resonance frequency of two inertial system models and the combination of antiresonant frequency.In step 4,, differentiate the group of wishing modeled two inertial systems according to purpose.For example, when the moment of inertia of the rigid body mode of obtaining entire system, select minimum frequency.In addition, when adjusting vibration damping at dither and be controlled to be purpose, be selected to the resonance frequency and the antiresonant frequency corresponding of problem with it.When there being a plurality of resonance frequencys, differentiate automatically when difficult, or when wishing that directly setting object is frequency, by step 5 manually selective reaonance frequency and antiresonant frequency.In step 6, come adjustment model by the curve fit of carrying out two inertial system models for the combination of selected resonance frequency and antiresonant frequency.In step 7, according to the model after this evaluation, the damping of the resonance frequency of adjusting, antiresonant frequency, moment of inertia and vibration.In addition, dotted line part 8 is the parts that are equivalent to patent documentation 3.

Below, step 6 and step 7 are elaborated.

If set resonance frequency ω H, antiresonant frequency ω L, damping ζ, total moment of inertia J, then the torque of two inertial system models to the transfer function of speed is represented by formula (1).

The amplitude of frequency field is converted gain H (ω) when representing as db, by formula (2) it is represented as the function of frequencies omega.If damping ζ is enough little here, then the intermediate point of resonance frequency ω H, antiresonant frequency ω L approx as the formula (5).

(formula 4)

$H\left(\frac{{\mathrm{\&omega;}}_L+{\mathrm{\&omega;}}_H}{2}\right)=20\log \left(\frac{2{{\mathrm{\&omega;}}_H}^2(3{\mathrm{\&omega;}}_L+{\mathrm{\&omega;}}_H)}{J{{\mathrm{\&omega;}}_L}^2({\mathrm{\&omega;}}_L+{\mathrm{\&omega;}}_H)({\mathrm{\&omega;}}_L+3{\mathrm{\&omega;}}_H)}\right)---\left(5\right)$

If the gain of the antiresonant frequency of obtaining by the frequency response computing is YL, the gain of resonance frequency is YH, but then total moment of inertia J through type (3) calculates.Gain adopts the mean value of peripheral several points to get final product.

, as initial value the model of employing formula (2) and the frequency response operation result that is obtained by mensuration are carried out curve fitting by the J that will obtain approx by formula (5) and ζ=0, come setting parameter.In curve fit, can use the whole bag of tricks such as least square method or genetic algorithm, the area between antiresonant frequency-resonance frequency is as shown in Figure 4 relatively reached intermediate point here and relatively describe.The real machine frequency characteristic 1 that expression is obtained by mensuration among the figure, two inertial system formula model frequency characteristics 2, evaluation starting point 3, evaluation end point 4.3 corresponding to antiresonant frequency, and 4 corresponding to resonance frequency.If expression regularization condition then as follows.

At first, at damping coefficient ζ,, then adjust with the condition of formula (6) if the gain that is obtained by the frequency characteristic computing is Y (ω).

(formula 5)

Here, δ is adjusted value arbitrarily, in addition, at total moment of inertia J, adjusts with following conditions.

(formula 6)

$\left\{\begin{array}{ccc}J=J+\mathrm{\&sigma;}& \mathrm{if}& H\left(\frac{{\mathrm{\&omega;}}_L+{\mathrm{\&omega;}}_H}{2}\right)>Y\left(\frac{{\mathrm{\&omega;}}_L+{\mathrm{\&omega;}}_H}{2}\right)\\ J=J-\mathrm{\&sigma;}& \mathrm{if}& H\left(\frac{{\mathrm{\&omega;}}_L+{\mathrm{\&omega;}}_H}{2}\right)<Y\left(\frac{{\mathrm{\&omega;}}_L+{\mathrm{\&omega;}}_H}{2}\right)\end{array}\right.---\left(7\right)$

Here, σ is adjusted value arbitrarily.Because when model was defined in two inertial systems, the condition of total moment of inertia through type (7) was easy to obtain, and obtains so damping coefficient can be judged with the consistent degree of the frequency characteristic that is obtained by mensuration by model.

The example of the concrete result that the adjusts when moment of inertia of rigid body mode of entire system is obtained in expression in Fig. 3, Fig. 4.Fig. 3 is the figure of expression based on the result that adjusts of existing method.Fig. 6 is the figure of expression based on the result of adjusting of the present invention.With respect to the frequency characteristic of measuring 1, the model of adjusting by curve fit is that conventional example is 5, is 2 based on model of the present invention.Machinery for 60 times of the moment of inertia exact values of rigid body mode, with in existing method, by the mean value of the slope of low frequency region adjust be 70 times relatively, by adopting this method, setting value is 55.5 times, compares the moment of inertia of can adjusting accurately as can be known with existing method.

Embodiment 2

Fig. 2 is the block diagram of the formation of expression the present invention the 2nd embodiment.Position control section 7 and speed controlling portion 8 in the 1st embodiment, have been appended.

In addition, for total moment of inertia of adjusting, also the frequency of the intermediate point of resonance frequency and antiresonant frequency can be chosen to be

The frequencies omega of ζ=0 o'clock _MThe gain H ' of two inertial system models (ω) represent by formula (8).

In addition, be YM if make the gain of the intermediate point of real machine frequency characteristic, then total moment of inertia J is represented by formula (9).

It is made to be used for adjusting as initial value get final product.

Because the moment of inertia of obtaining is used the frequency and the gain of resonance point and antiresonance point, even so in the modeling of many inertia machinery, also can obtain the spring constant and the moment of inertia of spring unit separately, therefore, the best that can be applied to corresponding therewith filter is set.

Even because controller for motor of the present invention is in less operation range, when the influence of friction or control is big, also can infer moment of inertia accurately, so can expect to be applied to based on the general industry machinery of robot or lathe etc.In addition, though the present invention is a prerequisite to be installed in the controller for motor, also can be used as the moment of inertia apparatus for predicting and use.

Claims (10)

1. controller for motor is to possess by the rate signal generating unit of position signalling formation speed signal and according to the controller for motor of the current control division of torque instruction control motor current, it is characterized in that possessing:

Test torque instruction generating unit generates the test torque instruction that comprises a plurality of frequency contents;

Real machine frequency characteristic calculating part goes out the real machine frequency characteristic by the RESPONSE CALCULATION at the described rate signal of described test torque instruction;

And the mechanical parameter generating unit, generate mechanical parameter by described real machine frequency characteristic.

2. controller for motor according to claim 1 is characterized in that possessing: position control section, by position command and the instruction of described position signalling formation speed; And speed controlling portion, generate described torque instruction by described speed command and described rate signal.

3. controller for motor according to claim 1 is characterized in that, described real machine frequency characteristic comprises resonance frequency and amplitude and antiresonant frequency and amplitude thereof.

4. according to claim 1 and 2 described controller for motor, it is characterized in that, the mechanical parameter generating unit makes total moment of inertia of two inertia formula models and damping coefficient minor variations repeatedly, make two inertia formula model frequency characteristics roughly consistent, described total moment of inertia and described damping coefficient are determined as parameter with the real machine frequency characteristic.

5. controller for motor according to claim 4 is characterized in that, by the described two inertial system formula models of formula (1) expression, by the intermediate-frequency gain of formula (2) expression antiresonant frequency and resonance frequency.

$G\left(s\right)=\frac{1}{\mathrm{Js}}\frac{{{\mathrm{\&omega;}}_H}^2}{{{\mathrm{\&omega;}}_L}^2}\frac{(s^2+2\mathrm{\&zeta;}{\mathrm{\&omega;}}_{L}s+{{\mathrm{\&omega;}}_L}^2)}{(s^2+2\mathrm{\&zeta;}{\mathrm{\&omega;}}_{H}s+{{\mathrm{\&omega;}}_H}^2)}---\left(1\right)$

$H\left(\mathrm{\&omega;}\right)=\left|G\left(\mathrm{j\&omega;}\right)\right|=20\log \left(\frac{{{\mathrm{\&omega;}}_H}^2\sqrt{{\mathrm{\&omega;}}^4-2{\mathrm{\&omega;}}^2{{\mathrm{\&omega;}}_L}^2+{{\mathrm{\&omega;}}_L}^4+4{\mathrm{\&zeta;}}^2{{\mathrm{\&omega;}}_L}^2{\mathrm{\&omega;}}^2}}{j{{\mathrm{\&omega;}}_L}^2\mathrm{\&omega;}\sqrt{{\mathrm{\&omega;}}^4-2{\mathrm{\&omega;}}^2{{\mathrm{\&omega;}}_H}^2+{{\mathrm{\&omega;}}_H}^2+4{\mathrm{\&zeta;}}^2{{\mathrm{\&omega;}}_H}^2{\mathrm{\&omega;}}^2}}\right)---\left(2\right)$

Here, J is total moment of inertia, ω _HBe resonance frequency, ω _LBe antiresonant frequency, ω is a test frequency, and ζ is a damping coefficient, and s is a Laplacian.

6. controller for motor according to claim 5, it is characterized in that, the antiresonant frequency of more described real machine frequency characteristic of mechanical parameter generating unit and described two inertial system formula model frequency characteristics is to the gain of the scope of resonance frequency, if the gain of described real machine frequency characteristic is bigger, then make the small increase of total moment of inertia of two inertial system formula models, if less then small minimizing proceeds to roughly till the unanimity repeatedly.

7. controller for motor according to claim 6 is characterized in that, the size of described gain is determined by comparing antiresonant frequency to the gain area of resonance frequency.

8. controller for motor according to claim 6 is characterized in that, the initial value of described total moment of inertia is formula (3),

$J=\frac{2{{\mathrm{\&omega;}}_H}^2(3{\mathrm{\&omega;}}_L+{\mathrm{\&omega;}}_H)}{e^{\frac{1}{40}(Y_L+Y_H)}{{\mathrm{\&omega;}}_L}^2({\mathrm{\&omega;}}_L+{\mathrm{\&omega;}}_H)({\mathrm{\&omega;}}_L+3{\mathrm{\&omega;}}_H)}---\left(3\right)$

But, Y _LBe the db conversion gain of the antiresonant frequency of real machine frequency characteristic, Y _HIt is the db conversion gain of resonance frequency.

9. controller for motor according to claim 6 is characterized in that, the initial value of described total moment of inertia is formula (5),

But, Y _MIt is the real machine frequency characteristic The time gain.

10. the control method of a controller for motor is to possess by the rate signal generating unit of position signalling formation speed signal and according to the control method of the controller for motor of the current control division of torque instruction control motor current, it is characterized in that possessing:

Comprise the test torque instruction of a plurality of frequency contents and obtain the step of real machine frequency characteristic to current control division input;

The step of more described real machine frequency characteristic and described two inertial system formula model frequency characteristics;

Total moment of inertia of small repeatedly correction and damping coefficient are so that the consistent step of gain of described real machine frequency characteristic and described two inertial system formula model frequency characteristics;

And the step of roughly total moment of inertia and damping coefficient being determined as parameter after the unanimity in described gain.

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