JP2010154674A - Disturbance compensating apparatus - Google Patents

Abstract

Disclosed is a disturbance compensator capable of compensating not only fluctuations in load torque acting on a motor, but also fluctuations in the effects of the armature inductance, DC resistance (fluctuated greatly due to heat generation) and back electromotive force constant of the motor. .
A speed sensor 11 for detecting a rotation speed of a motor 3 and an influence composite signal reflecting an influence of an armature inductance L, a DC resistance R, and a counter electromotive force E _emf of the motor 3 on the rotation operation of the motor 3. A combined signal generating unit 13 that generates ω (JLs ² + JRs + K _t K _emf ) from the rotational speed ω, and a correcting unit 15 that corrects the power supply command value E _i based on the influence combined signal.
[Selection] Figure 1

Description

  The present invention relates to a disturbance compensator that is incorporated in a control device that controls the rotational operation of a motor and compensates for fluctuations in load torque acting on the motor.

A conventional disturbance compensator will be described with reference to FIG. FIG. 2 is a block diagram showing a conventional disturbance compensation device 20 incorporated in the control device 23 of the motor 21.
Definitions of symbols used in FIG. 2 and the following description are as follows. In the following, [] is a unit.
I _i : Current control command value I: Current value supplied to motor 21 [A]
K _t : Torque constant of motor 21 [Nm / A]
J _m : inertia (inertia) of the motor 21 [kg · m ² ]
T _L : Load torque acting on the motor 21 [Nm]
ω: rotational angular velocity of the motor 21 [rad / s]
ω _c : Cut-off frequency [rad / s]
s: Laplace operator

The control device 23 includes a motor driver 25 that supplies power to the motor 21 and a command unit 27 that outputs a current control command value Ii to the motor driver 25. The motor driver 25 supplies a current based on the current control command value I _i to the motor 21.

The motor 21 will be described. By supplying the motor 21 with the current I from the motor driver 25, the torque of IK _t is applied to the motor 21. On the other hand, a load torque _TL such as friction or load acts on the motor 21. Thus, net torque acting on the motor 21, the _IK t -T _L. In this case, the rotation angular velocity ω of the motor _21, the _{(IK t -T L) / J} m s.

Disturbance compensation device 20, based on the rotation angular velocity _{ω = (IK t -T L)} / J m s of the above motor 21, by correcting the current control command value _{I i,} to compensate for the load torque described above. The disturbance compensator 20 includes a command torque calculation unit 29, a speed sensor 31, a speed torque conversion unit 33, a deviation calculation unit 35, a unit adjustment unit 37, and a correction unit 39.
The command torque calculation unit 29 calculates a torque value IK _t from the product of the current value I supplied to the motor 21 by the motor driver 25 and the torque constant K _t .
The speed sensor 31 detects the rotational angular speed ω of the motor 21.
Speed torque converting section 33 calculates the torque value .omega.j m _s by the product of the rotational angular velocity ω and J _{m s.}
Deviation calculating section 35, a torque value IK _t from the command torque calculation section 29 calculates the torque deviation _IK t _{-ωJ m} s of the torque value .omega.j _m s from the speed torque converting unit 33 outputs.
Unit adjusting unit 37 calculates the torque deviation _IK t _{-ωJ m} multiplied by the value 1 / _{K t} in _{s (IK t -ωJ m s)} / K t from deviation calculating section 35.
Correcting unit 39, the output from the unit adjusting unit 37 _{(IK t -ωJ m s) /} K t, by adding to the current control command value _{I i,} corrects the current control command value _{I i.}
Reference numeral 41 denotes a low-pass filter.

In the configuration of the disturbance compensator 20 described above, the torque value .omega.j m _s speed torque converting section 33 has calculated, the load torque, including such as load torque and friction and moment of inertia is one that is reflected, the correction unit 39 but the _{(IK t -ωJ m s) /} K t, by adding to the current control command value _{I i,} it is possible to eliminate the influence of load torque fluctuation.

The disturbance compensator 20 as described above is described in Non-Patent Document 1 below, for example. Moreover, there are the following Patent Documents 1 to 4 as other prior art documents for the present application.
Japanese Patent Laid-Open No. 03-155383 JP 11-285283 A JP 2002-366203 A Japanese Patent Laid-Open No. 2007-233917 Journal of the Robotics Society of Japan Vol. 11 No. 4, pp. 486-493, May 1993

However, in the configuration of FIG. 2, the armature inductance, DC resistance, and counter electromotive force constant of the motor are not considered, and fluctuations in these effects cannot be removed.
Therefore, an object of the present invention is to provide a disturbance that can compensate not only for fluctuations in load torque acting on the motor, but also for fluctuations in the influence of the armature inductance, DC resistance (which varies greatly due to heat generation) and the back electromotive force constant of the motor. It is to provide a compensation device.

In order to achieve the above object, according to the present invention, there is provided a disturbance compensator that is incorporated in a control device that controls the rotational operation of a motor and compensates for fluctuations in load torque acting on the motor,
The control device includes:
A motor driver for applying a voltage to the motor;
A command unit that outputs a power supply command value to the motor driver, and the motor driver applies a voltage to the motor based on the power supply command value,
The disturbance compensator is:
A speed sensor for detecting the rotational speed of the motor;
A combined signal generating unit that generates an influence combined signal reflecting the influence of the armature inductance, DC resistance, and counter electromotive force of the motor on the rotation operation from the rotation speed;
There is provided a disturbance compensation device comprising: a correction unit that corrects the power supply command value based on the influence synthesis signal.

  According to the disturbance compensator according to the present invention described above, the composite signal generation unit generates an influence composite signal that reflects the influence of the armature inductance, DC resistance, and counter electromotive force of the motor on the rotation operation. Generated from the affected rotational speed, and the correction unit corrects the power supply command value based on the influence composite signal, so that not only the motor load torque fluctuation, but also the armature inductance of the motor, The power supply command value can be corrected so as to compensate and remove the fluctuation of the influence of the DC resistance and the counter electromotive force constant. Therefore, a disturbance compensator capable of obtaining a wider compensation effect is realized.

According to a preferred embodiment of the present invention, the value of the voltage which the motor driver applied to the motor based on the power supply command value and E, a torque constant of the motor and K _t, the armature inductance of the motor L , R is the DC resistance of the motor, K _emf is the back electromotive force constant of the motor, J _m is the inertia of the motor, ω is the rotational angular velocity of the motor that is the rotational speed, and Laplace operator is s and α as a constant of 1 or other values,
The correction unit calculates αω (J _m Ls ² + J _m Rs + K _t K _emf ) as the influence synthesized signal.

As will be described later, ω (J _m Ls ² + J _m Rs + K _t K _emf ) is a signal reflecting the influence of the armature inductance, DC resistance, and counter electromotive force of the motor on the rotation operation. Therefore, by correcting the power supply command value based on such an influence composite signal, the motor armature inductance, DC resistance, and back electromotive force constant influence fluctuations are also compensated and removed. The power supply command value can be corrected.

  Specifically, the correction unit may correct the power supply command value with the following configuration.

When β is a constant of 1 or another value and the voltage E is βE _i ,
The correction unit is
A deviation calculating unit for calculating a deviation _{ΔD = αβE i K t -αω (} J m Ls 2 + J m Rs + K t K emf),
Having, an addition unit for adding the deviation ΔD to the power supply command value E _i.

  According to the present invention described above, not only the fluctuation of the load torque acting on the motor but also the fluctuation of the influence of the armature inductance, DC resistance and counter electromotive force constant of the motor can be compensated.

  The best mode for carrying out the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

FIG. 1 is a block diagram showing a disturbance compensator 10 according to an embodiment of the present invention.
The disturbance compensation device 10 according to the present embodiment is incorporated in the control device 5 that controls the rotational operation of the motor 3 and compensates for fluctuations in load torque acting on the motor 3.

First, symbols used in FIG. 1 and the following description will be described. The definition of each symbol is as follows. In the following, [] is a unit.
E _i : Power supply command value E: Voltage value supplied to the motor 3 [V]
E _emf : _Back electromotive force of motor 3 [V]
I: Current value [V] supplied to the motor 3
T _L : Load torque of motor 3 [Nm]
ω _m : rotational angular velocity of motor 3 [rad / s]
θ _m : rotation angle of motor 3 [rad]
K _t : Torque constant of motor 3 [Nm / A]
L: Inductance [H] of the armature of the motor 3
R: DC resistance of motor 3 [R]
J _m : Inertia of motor 3 [kg · m ² ]
K _emf : _Back electromotive force constant [V / (rad / s)]
ζ: damping ratio ω _c: cut-off frequency [rad / s]
s: Laplace operator

The control device 5 includes a motor driver 7 that supplies power to the motor 3 and a command unit 9 that outputs a power supply command value E _i to the motor driver 7. The motor driver 7 supplies a voltage E to the motor 3 based on the power supply command value E _i . The voltage E may be E = βE _i where β is a constant of 1 or another value, but β = 1 in the following description for simplicity.
The control device 5 may output the power supply command value E _i from the command unit 9 based on the rotational angular velocity ω of the motor 3, the rotational angle θ of the motor 3, and the like. As a control method of the control device 5, for example, feedback control, feedforward control, or the like may be employed.

  The disturbance compensation apparatus 10 includes a speed sensor 11, a composite signal generation unit 13, and a correction unit 15.

  The speed sensor 11 detects the rotational speed of the motor 3 (in this example, the rotational angular speed ω).

The combined signal generation unit 13 detects the rotational speed detected by the speed sensor 11 from the combined effect signal that reflects the influence of the armature inductance L, the DC resistance R, and the back electromotive force E _{emf of the} motor 3 on the rotational operation. (In this example, it is generated from the rotational angular velocity ω).
In the example of FIG. 1, the combined signal generation unit 13 affects ω (J _m Ls ² + J _m Rs + K _t K _emf ) by the product of the rotational angular velocity ω and (J _m Ls ² + J _m Rs + K _t K _emf ). Calculate and output as a composite signal. Here, with α being a constant of 1 or another value, the combined signal generation unit 13 may output a combined signal that affects αω (J _m Ls ² + J _m Rs + K _t K _emf ). In the explanation, α = 1.

The correcting unit 15 corrects the power supply command value E _i based on the influence combined signal.
In the example of FIG. 1, the correction unit 15 corrects the power supply command value E _i as follows. The correction unit 15 includes a unit conversion unit 15a, a deviation calculation unit 15b, a unit inverse conversion unit 15c, and an addition unit 15d.

The unit converter 15a calculates EK _t by the product of the voltage value E and the torque constant K _t so that the unit of the voltage E applied by the motor driver 7 to the motor 3 is the same as the unit of the influence synthesis signal. And output.

The deviation calculation unit 15b is a deviation EK _t −ω (J _m Ls ² + J _m ) between the output EK _t of the unit conversion unit 15a and the output ω (J _m Ls ² + J _m Rs + K _t K _emf ) of the combined signal generation unit 13. Rs _{+ K t} K _emf) and outputs them.

The unit inverse conversion unit 15c converts the output of the deviation calculation unit 15b into the power supply command value E _i by unit conversion, so that the output EK _t −ω (J _m Ls ² + J _m Rs + K _t K _{emf of the} deviation calculation unit 15b. ) and, by the product of the reciprocal 1 / _{K t} of the torque constant, and outputs the calculated ^{_{{EK t -ω (J m Ls}} 2 + J m Rs + K t K emf)} / K t. As in the example of FIG. 1, the unit inverse converter 15c calculates {EK _t − − by the product of the output of the deviation calculator 15b that has passed through the secondary low-pass filter 15e and the inverse 1 / K _t of the torque constant. ω (J _m Ls ² + J _m Rs + K _t K _emf )} / K _t is preferably calculated and output.

The adder 15d adds the voltage value E applied by the motor driver 7 to the motor 3 and the output {EK _t −ω (J _m Ls ² + J _m Rs + K _t K _emf )} / K _{t of} the unit inverse converter 15c. Thus, E + {EK _t −ω (J _m Ls ² + J _m Rs + K _t K _emf )} / K _t is calculated and output. The output E + {EK _t −ω (J _m Ls ² + J _m Rs + K _t K _emf )} / K _t of the adding unit 15d is input to the motor driver 7 as the corrected power supply command value E _i .

Note that J _m , L, R, K _emf , and K _t used in the calculation in the disturbance compensation apparatus 10 may be nominal values (nominal values).

The effects of the combined signal generation unit 13 and the correction unit 15 will be described in relation to the voltage affected by the inductance of the motor 3 and the like.
(About voltage)
A voltage E is applied to the motor 3 by the motor driver 7. On the other hand, the counter electromotive force E _emf = ωK _emf due to the rotational motion of the motor 3 is generated in the motor 3. Therefore, the net voltage value applied to the motor 3 is E−E _emf = E−ωK _emf .
(About current)
Since the net voltage applied to the motor 3 is E−ωK _emf , the direct current resistance of the motor 3 is R, and the inductance of the motor 3 is L, the Laplace operator is s, and the current flowing through the motor 3 is ( E−ωK _emf ) / (Ls + R).
(About torque)
The current flowing through the motor _{3, (E-ωK emf)} / are the (Ls + R), a torque constant as _{K t,} the torque applied to the motor 3 by a _{current, K t (E-ωK emf} ) / (Ls + R) It becomes. Meanwhile, since the motor 3 acting load torque _{T L} is the net torque of the motor 3 _{becomes K t (E-ωK emf)} / (Ls + R) -T L.
(Rotational angular velocity)
The net torque of the motor _3, since it is _{K t (E-ωK emf)} / (Ls + R) -T L, the inertia of the motor 3 and _{J m,} the Laplace operator as s, the rotation angular velocity ω of the motor 3 is , Ω = {K _t (E−ωK _emf ) / (Ls + R) −T _L } / J _m s.
(About the influence synthetic signal)
When ω = {K _t (E−ωK _emf ) / (Ls + R) −T _L } / J _m s is transformed,
EK _t = ω (J _m Ls ² + J _m Rs + K _t K _emf ) + T _L (Ls + R)
It becomes.
In this equation, when EK _t on the left side is converted into electric energy, it can be considered that the electric energy is converted into the energy of the first term on the right side and the energy of the second term on the right side. Among these, the first term on the right side can be regarded as the kinetic energy of the motor 3, and the second term on the right side can be regarded as energy lost due to the influence of the load torque, the armature inductance, and the DC resistance.
Therefore, by increasing the voltage E (that is, the power supply command value E _i ) supplied to the motor 3 by a value corresponding to the second term T _L (Ls + R) on the right side, load torque, armature inductance, and DC resistance are increased. The fluctuation of the influence can be removed. Note that the DC resistance varies greatly due to heat generation.
Specifically, the synthesized signal generating unit 13 and the correction unit 15, as described _above, a correction to increase by a value corresponding to T L (Ls + R), _{i.e., T L (Ls + R)} / K t = {EK t -Ω (J _m Ls ² + J _m Rs + K _t K _emf )} / K _t is corrected for the power supply command value E _i to change the influence of load torque, armature inductance, and DC resistance. Can be removed.

According to the disturbance compensator 10 according to the present embodiment, the combined signal generation unit 13 generates an influence combined signal that reflects the influence of the armature inductance, DC resistance, and counter electromotive force of the motor 3 on the rotational operation. The correction unit 15 corrects the power supply command value E _i on the basis of the influence synthesis signal, so that not only the load torque fluctuation of the motor 3 but also the The power supply command value E _i can be corrected so as to compensate and remove fluctuations in the influence of the armature inductance, DC resistance, and counter electromotive force constant of the motor 3. Therefore, the disturbance compensation apparatus 10 that can obtain a wider compensation effect is realized.
As described above, ω (J _m Ls ² + J _m Rs + K _t K _emf ) is a signal reflecting the influence of the armature inductance, DC resistance, and counter electromotive force of the motor 3 on the rotation operation. . Therefore, by correcting the power supply command value E _i based on such an effect synthesis signal, fluctuations in the effects of the armature inductance, DC resistance, and counter electromotive force constant of the motor 3 are also compensated and removed. Thus, the power supply command value E _i can be corrected.

  The present invention is not limited to the above-described embodiment, and various changes can be made without departing from the scope of the present invention.

In the above description, β = 1 and α = 1 have been described for simplicity. However, β and α may be constants other than 1. In this case, E = βE _i , and the combined signal generation unit 13 outputs αω (JLs ² + JRs + K _t K _emf ) as an influence combined signal. In this case, the unit converter 15a multiplies αK _t by the voltage E to calculate and output αEK _t , and the unit inverse converter 15c converts 1 / αβK _t to the output from the deviation calculator 15b. Multiply. In this case, the other configurations may be the same as described above.

It is a block diagram which shows the disturbance compensation apparatus by embodiment of this invention. It is a block diagram which shows the conventional disturbance compensation apparatus.

Explanation of symbols

3 motor, 5 control device, 7 motor driver, 9 command section,
10 disturbance compensator, 11 speed sensor, 13 synthesized signal generator,
15 correction unit, 15a unit conversion unit, 15b deviation calculation unit,
15c unit inverse conversion unit, 15d addition unit, 15e secondary low-pass filter 20 disturbance compensation device, 21 motor, 23 control device,
25 motor driver, 27 command section, 29 command torque calculation section,
31 speed sensor, 33 speed torque conversion unit, 35 deviation calculation unit,
37 unit adjustment unit, 39 correction unit, 41 low-pass filter

Claims (3)

A disturbance compensator that is incorporated in a control device that controls the rotational operation of a motor and compensates for fluctuations in load torque acting on the motor,
The control device includes:
A motor driver for applying a voltage to the motor;
A command unit that outputs a power supply command value to the motor driver, and the motor driver applies a voltage to the motor based on the power supply command value,
The disturbance compensator is:
A speed sensor for detecting the rotational speed of the motor;
A combined signal generating unit that generates an influence combined signal reflecting the influence of the armature inductance, DC resistance, and counter electromotive force of the motor on the rotation operation from the rotation speed;
A disturbance compensation device comprising: a correction unit that corrects the power supply command value based on the influence synthesis signal. The value of the voltage which the motor driver applied to the motor based on the power supply command value and E, a torque constant of the motor and K _t, the armature inductance of the motor is L, the DC resistance of the motor R The motor back electromotive force constant is K _emf , the inertia of the motor is J _m , the rotational angular velocity of the motor, which is the rotational speed, is ω, the Laplace operator is s, and α is 1 or another As a value constant,
The disturbance correcting apparatus according to claim 1, wherein the correction unit calculates αω (J _m Ls ² + J _m Rs + K _t K _emf ) as the influence synthesis signal. When β is a constant of 1 or another value and the voltage E is βE _i ,
The correction unit is
A deviation calculating unit for calculating a deviation _{ΔD = αβE i K t -αω (} J m Ls 2 + J m Rs + K t K emf),
The disturbance compensation apparatus according to claim 2, further comprising: an addition unit that adds the deviation ΔD to the power supply command value E _i .

Images