JP7120821B2 - Control device, control method and program - Google Patents

Description

The present invention relates to a control device, control method and program.

In actuators that drive machines, deterioration in positioning accuracy occurs mainly due to the nonlinearity of friction elements, and deterioration in quality is a problem. The stick-slip phenomenon caused by frictional fluctuations on the slip surface is a vibration phenomenon that is caused by repeated stopping and moving due to static friction, especially during low-speed operation.

As a method for reducing the influence of such friction, Patent Document 1 discloses that a control device includes torque command calculation means for calculating a torque command for a mechanical device and friction estimation means for calculating an estimated value of the frictional force generated in the mechanical device. adjusting means for calculating a correction value by multiplying the estimated value calculated by the friction estimating means by a predetermined gain; and adjusting means for calculating the torque command calculated by the torque command calculating means. and correction means for correcting with the correction value, wherein the gain is determined based on the gain characteristics of the transfer function from the position command to the position deviation for the mechanical device. .

Japanese Patent No. 6177705

Frictional force increases under the influence of static friction at low speeds, and the frictional force also abruptly changes when the direction of movement is reversed. Therefore, there is a problem that the correction value becomes oscillating due to the estimation error. This problem becomes conspicuous when using a highly accurate friction model.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a control device, a control method, and a program capable of preventing oscillation of a correction value by appropriately correcting the frictional force. do.

According to the first aspect of the present invention, a control device includes a command value acquisition unit that acquires a command value for a controlled machine, an observed value acquisition unit that acquires an observed value for the controlled machine, and the command value a control unit that controls the controlled machine so as to eliminate the difference between the observed value and the observed value; and a frictional force acting on the controlled machine based on the observed value and a friction model applied to the controlled machine. a friction calculation unit; and a compensation unit that compensates for a phase shift with the controlled machine in a control loop with respect to the frictional force and corrects the command value.

Further, according to the second aspect of the present invention, the apparatus further includes a correction unit that corrects the command value further based on the moving direction of the controlled machine indicated by the command value.

Further, according to the third aspect of the present invention, the observed value is a position parameter of the load of the controlled machine whose position changes under the control of the control unit, and the friction calculation unit is a position parameter of the load is differentiated and converted into the moving speed of the load in the machine to be controlled.

Further, according to the fourth aspect of the present invention, the observed value is a motor angle, which is a rotation angle of a motor of the controlled machine whose rotation angle changes under the control of the control unit, and the friction calculation unit is , using the transfer function of the controlled machine and a notch filter, the motor angle is converted into the moving speed of the load of the controlled machine whose position changes under the control of the control unit.

Further, according to the fifth aspect of the present invention, the speed of the controlled machine is determined based on the deviation between the command value and the observed value and a physical model applied to the controlled machine, and the determined speed and the A first disturbance observer section that corrects the command value further based on a deviation from a value based on an observed value is further provided.

Further, according to the sixth aspect of the present invention, the speed of the controlled machine is determined based on the deviation between the command value and the observed value and a physical model corresponding to the controlled machine, and the determined speed and the a second disturbance observer unit that generates a correction value based on a deviation from a value based on an observed value and outputs the generated correction value to the friction calculation unit; The calculated frictional force is updated based on the correction value output by the disturbance observer unit.

Further, according to the seventh aspect of the present invention, the speed of the controlled machine is obtained based on the deviation between the command value and the observed value and a physical model corresponding to the controlled machine, and the obtained speed and the observed speed are calculated. a third disturbance observer that generates a correction value based on a deviation from a value based on the value and outputs the generated correction value to the compensator, wherein the compensator is the third disturbance observer The command value is corrected based on the correction value output by the unit.

Further, according to an eighth aspect of the present invention, a control device includes a command value acquisition unit that acquires a command value for a machine to be controlled, an observation value acquisition unit that acquires an observation value for the machine to be controlled, and a control unit for controlling the controlled machine so as to eliminate the difference between the command value and the observed value; and a frictional force acting on the controlled machine based on the observed value and a friction model corresponding to the controlled machine. and a correction unit for correcting the command value by correcting the value based on the frictional force based on the movement direction of the controlled machine indicated by the command value.

Further, according to the ninth aspect of the present invention, the control method includes the step of obtaining a command value for a machine to be controlled by a command value obtaining unit; a step in which an observed value acquisition unit acquires; a control unit controls the controlled machine so as to eliminate the difference between the command value and the observed value; determining a frictional force acting on the controlled machine based on the applied friction model; and compensating the frictional force for a phase shift with the controlled machine in a control loop. and a step of correcting the command value.

Further, according to the tenth aspect of the present invention, a control method includes the steps of: a command value acquisition unit acquiring a command value for a machine to be controlled; and a control unit controlling the controlled machine so as to eliminate the difference between the command value and the observed value; a step of obtaining a frictional force acting on the controlled machine based on the command value, and a correction unit correcting the value based on the frictional force based on the moving direction of the controlled machine indicated by the command value to determine the command value. and performing a correction.

Further, according to the eleventh aspect of the present invention, the program provides a computer of a control device that controls the controlled machine with a step of obtaining a command value for the controlled machine and an observed value for the controlled machine. a step of controlling the controlled machine so as to eliminate the difference between the command value and the observed value; and based on the observed value and a friction model applied to the controlled machine, the obtaining a frictional force acting on a machine to be controlled; and compensating for a phase shift with the machine to be controlled in a control loop for the frictional force to correct the command value. .

Further, according to the eleventh aspect of the present invention, the program provides a computer of a control device that controls the controlled machine with a step of obtaining a command value for the controlled machine and an observed value for the controlled machine. and controlling the controlled machine to eliminate the difference between the command value and the observed value, acting on the controlled machine based on the observed value and a friction model corresponding to the controlled machine. A step of obtaining a frictional force and a step of correcting the command value by correcting the value based on the frictional force based on the movement direction of the controlled machine indicated by the command value are executed.

According to each aspect of the invention described above, it is possible to prevent the correction value from oscillating by appropriately correcting the frictional force.

1 is a diagram showing drive components of one axis of a machine tool having a control device according to a first embodiment; FIG. 3 is a block diagram showing the functional configuration of a control device according to the first embodiment; FIG. FIG. 4 is a diagram showing an example of a friction model; 6 is a flow chart showing an example of a processing procedure performed by a correction unit according to the first embodiment; It is a figure which shows the example which the control apparatus which concerns on 1st Embodiment analyzed the result of having controlled the controlled object machine. It is a block diagram which shows the structural example of the machine tool in a comparative example. FIG. 9 is a diagram showing an example of analysis of results of control of a controlled machine by a control device in a comparative example; It is a figure which shows the example of a stick-slip phenomenon. FIG. 2 is a diagram showing a physical model of a machine to be controlled and a friction compensator according to the first embodiment; It is a block diagram which shows the functional structure of the control apparatus which concerns on 2nd Embodiment. FIG. 11 is a block diagram showing the functional configuration of a control device according to a third embodiment; FIG. FIG. 11 is a block diagram showing the functional configuration of a control device according to a fourth embodiment; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in the drawings used for the following description, the scale of each member is appropriately changed so that each member has a recognizable size.

<First embodiment>
[Example of drive configuration for one axis of a machine tool]
First, an example of a drive configuration for one axis of a machine tool will be described.
FIG. 1 is a diagram showing uniaxial drive components of a machine tool 1 having a control device 10 according to the present embodiment. As shown in FIG. 1, the machine tool 1 includes a control device 10 and a machine 2 to be controlled.

The control device 10 controls the controlled machine 2 such that the observed value of the controlled machine 2 matches a command value input from a host device (not shown). A host device is, for example, a computer or the like. Specifically, the control device 10 controls the motor position observation value θ _M that is the observed value of the machine 2 (motor 21) to be controlled, and the motor position command value θ _M * input from the host device. is output to the machine 2 to be controlled. Thereby, the control device 10 performs positioning control of the table 23 of the machine 2 to be controlled, for example.

The machine 2 to be controlled is a mechanical movable mechanism of the machine tool 1, and has a motor 21, a gear 22, and a table 23, for example. As shown in FIG. 1, the motor 21 and the gear 22, and the gear 22 and the table 23 are respectively connected by a connecting member such as a ball screw, and the torque generated by the motor 21 is transmitted to the table 23 as a load. Construct a mechanism to The motor 21 is, for example, a servomotor. An encoder is attached to the controlled machine 2 . The encoder of the controlled machine 2 outputs the observed value of the load angle to the control device 10 .

[Example of functional configuration of control device 10]
Next, a functional configuration example of the control device 10 will be described.
FIG. 2 is a block diagram showing the functional configuration of the control device 10 according to this embodiment.
As shown in FIG. 2 , the control device 10 includes a control section 101 and a friction compensation section 16 . The control device 10 controls the controlled machine 2 .
The control unit 101 includes a position proportional control unit 11 (command value acquisition unit, observation value acquisition unit), a velocity proportional integral control unit 12, a calculation unit 13, a current control unit 14, and a pseudo differentiation unit 15 (observation value acquisition unit). Prepare.
The friction compensator 16 also includes a difference calculator 161 (command value acquirer), a friction calculator 162 (observed value acquirer), a compensator 163 , and a corrector 164 .
The friction calculation section 162 includes a conversion section 1621 and a friction model storage section 1622 .
The compensation section 163 includes a friction compensation filter storage section 1631 .

Note that the controlled machine 2 includes, for example, the motor 21, the gear 22, and the table 23, as described with reference to FIG. An encoder (not shown) is attached to the table 23 which is the load of the controlled machine 2 .

The position proportional control unit 11 calculates the deviation (θ _M *−θ _M ) between the motor position command value θ _M * input from the host device and the motor position observation value θ _M input from the motor 21 (FIG. 1). Generate a motor speed command value ω _M * (control signal) of proportional magnitude. The position proportional control unit 11 outputs the generated motor speed command value ω _M * to the speed proportional integral control unit 12 and the difference calculation unit 161 .

The speed proportional integral control unit 12 calculates the deviation (ω _M *−ω _M ) between the motor speed command value ω _M * output by the position proportional control unit 11 and the motor speed observed value ω _M output by the pseudo differentiating unit 15, and A torque command value τ* (control signal) having a magnitude proportional to the time integral is generated. The speed proportional integral control unit 12 outputs the generated torque command value τ* to the calculation unit 13 .

The calculation unit 13 adds the correction torque command value Δτ* (correction command value) output by the correction unit 164 of the friction compensation unit 16 to the torque command value τ* (control signal) output by the speed proportional integral control unit 12. . The calculation unit 13 outputs the torque command value τ* after addition to the current control unit 14 .

The current control unit 14 outputs a motor current corresponding to the torque command value τ* output by the calculation unit 13 to the controlled machine 2 . The motor 21 (FIG. 1) of the controlled machine 2 outputs a torque τ that matches the torque command value τ* by this motor current.

The pseudo differentiating section 15 generates a motor speed observed value ω _M by pseudo differentiating the motor position observed value θ _M input from the motor 21 (FIG. 1). The pseudo differential unit 15 outputs the generated motor speed observed value ω _M to the speed proportional integral control unit 12 .

The friction compensator 16 compensates for the influence of friction based on the encoded value (observed value) detected by the encoder of the controlled machine 2 and the motor position command value θ _M * to obtain a corrected torque command value Δτ* (correction command value). The corrected torque command value Δτ* is a correction value of the command value for compensating for the phase shift (phase delay or phase lead) in the control loop. The encoded value (observed value) is a position parameter of the load of the controlled machine 2 whose position changes under the control of the control unit 101 .

The difference calculator 161 obtains the difference between the motor position command values θ _M * for each predetermined time as an angle command difference value. For example, the difference calculator 161 obtains the angle command difference value between the motor position command value θ _M * at the first time and the motor position command value θ _M * at the second time after the first time by a predetermined time. The difference calculation unit 161 outputs the calculated angle command difference value Δθ _M * to the correction unit 164 . The angle command difference value Δθ _M * indicates the direction of rotation (rotation in the positive direction, rotation in the negative direction) in the torque command.

The conversion unit 1621 of the friction calculation unit 162 converts the measurement signal θ (observed value) of the load angle output by the encoder on the load side into the moving speed of the load by, for example, differentiation processing.

The friction model storage unit 1622 stores a friction model that models friction force with respect to velocity. Note that the friction model stored in the friction model storage unit 1622 will be described later using FIG.

The friction calculation unit 162 uses the speed converted by the conversion unit 1621 to refer to the friction model stored in the friction model storage unit 1622, and obtains the friction amount corresponding to the speed, thereby obtaining an estimated friction value (correction command value). Ask for Note that when the friction model is represented by a formula, the friction calculation unit 162 may obtain the friction estimated value (correction command value) by calculation.

The friction compensation filter storage unit 1631 stores a friction compensation filter that cancels the influence of friction. An example of how to obtain the friction compensation filter will be described later with reference to FIG.

Compensation unit 163 uses the friction compensation filter stored in friction compensation filter storage unit 1631 for the estimated friction value output from friction calculation unit 162 to obtain a friction compensation value that compensates for the phase lag and phase lead of the multi-inertia system. (value based on frictional force, correction command value).

The correction unit 164 corrects the friction compensation value output by the compensation unit 163 according to the angle command difference value Δθ _M * calculated by the difference calculation unit 161 . The correction unit 164 outputs the corrected value to the calculation unit 13 as the corrected torque command value Δτ*.

[Friction model example]
Next, an example of the friction model stored in the friction model storage unit 1622 will be described.
FIG. 3 is a diagram showing an example of a friction model. In FIG. 3, the horizontal axis is velocity [deg/s] and the vertical axis is frictional force [Nm].
Symbol g1 is the characteristic of frictional force against speed during acceleration. The frictional force of symbol g1 changes in the direction of increasing speed from zero as indicated by symbol g11.
Symbol g2 is the characteristic of frictional force with respect to speed during deceleration. The frictional force of symbol g2 changes in the direction of decreasing speed from about 50 as indicated by symbol g12.
Note that the characteristics shown in FIG. 3 are simulation values. Such a friction model is calculated using, for example, a physical model of the controlled machine 2, which will be described later with reference to FIG. Therefore, the friction model differs depending on the machine 2 to be controlled.

[Processing example of correction unit]
Next, an example of processing performed by the correction unit 164 will be described.
FIG. 4 is a flowchart showing an example of a processing procedure performed by the correction unit 164 according to this embodiment.

(Step S<b>1 ) The correction unit 164 acquires the angle command difference value Δθ _M * output by the difference calculation unit 161 . Subsequently, the correction unit 164 determines whether the acquired angle command difference value Δθ _M * is positive, 0, or negative. Thereby, the correction unit 164 determines the movement direction of the controlled machine 2 indicated by the command value. When the correction unit 164 determines that the angle command difference value Δθ _M * is positive (step S1; positive), the process proceeds to step S2. When the correction unit 164 determines that the angle command difference value Δθ _M * is 0 (step S1; 0), the process proceeds to step S3. When the correction unit 164 determines that the angle command difference value Δθ _M * is negative (step S1; negative), the process proceeds to step S4.

(Step S2) The correction unit 164 performs friction compensation only in the forward direction. In other words, the correction unit 164 outputs the corrected torque command value Δτ* when the friction compensation value is positive, and outputs 0 as the corrected torque command value Δτ* when the friction compensation value is 0 or negative.

(Step S3) The correction unit 164 does not perform friction compensation. In other words, the correction unit 164 outputs 0 as the corrected torque command value Δτ*.

(Step S4) The correction unit 164 performs friction compensation only in the negative direction. In other words, the correction unit 164 outputs the corrected torque command value Δτ* when the friction compensation value is negative, and outputs 0 as the corrected torque command value Δτ* when the friction compensation value is 0 or positive.

The significance of the correction unit 164 processing as shown in FIG. 4 will be described.
As shown in FIG. 2 , the control device 10 performs feedback control on the controlled machine 2 . Therefore, if the table 23 (FIG. 1) advances too much, the torque command value τ* output by the speed proportional integral control unit 12 is a control value that returns the excessive advance. If the corrector 164 outputs a correction torque command value Δτ* for further returning when the table 23 advances too much, the table 23 will return too much, which will promote the stick-slip vibration of the table 23 . It could be. For this reason, in the present embodiment, by correcting the output of the friction compensation value according to the angle command difference value Δθ _M *, vibration due to the stick-slip phenomenon is prevented from being promoted. Note that the stick-slip phenomenon is a vibration phenomenon caused by adhesion of a friction surface caused by friction and repetition of slippage.

[Analysis result example]
Next, an example of analyzing the results of the control of the controlled machine 2 by the control device will be described.
FIG. 5 is a diagram showing an example of analysis of the results of control of the controlled machine 2 by the control device 10 according to this embodiment. In addition, in FIG. 5, the control is started at time 1. As shown in FIG.

FIG. 5(A) is the analysis result of the angle change with respect to time. In FIG. 5A, the horizontal axis is time [s] and the vertical axis is angle [deg].
Symbol g31 indicates the change in angle on the motor side. Symbol g32 indicates the change in angle on the load side. Symbol g33 indicates a change in reference angle in which the stick-slip phenomenon does not occur.

FIG. 5(B) is the analysis result of the change in angle error with respect to time. In FIG. 5B, the horizontal axis is time [s] and the vertical axis is angle error [deg].
Symbol g34 indicates the change in angle error on the motor side. Symbol g35 indicates the change in angle error on the load side.

FIG. 5(C) is an analysis result of changes in input torque with respect to time. In FIG. 5C, the horizontal axis is time [s] and the vertical axis is input torque [Nm].
Symbol g36 indicates a change in integrated torque (Total Torque). Symbol g37 indicates a change in friction compensation.

According to this embodiment, as shown in FIG. 5B, the angle error between the motor side and the load side converges within 1 to 2 seconds. Then, as shown in FIG. 5B, the change in the angle error value between the motor side and the load side after 2 seconds is almost 0, that is, the vibration is suppressed. As a result, as shown in FIG. 5A, the stick-slip phenomenon can be suppressed.
Further, according to the present embodiment, the compensator 163 compensates for phase lag and phase advance in the control loop to generate the correction command value, which is the correction value of the command value. It is possible to reduce the effects of lag and damping until , and correctly compensate for friction.

Next, in the machine tool 900 of the comparative example, the results of the control of the controlled machine 2 by the control device will be described.
First, a configuration example of a machine tool 900 in a comparative example will be described.
FIG. 6 is a block diagram showing a configuration example of a machine tool 900 in a comparative example. As shown in FIG. 6, a machine tool 900 includes a control device 910 and a machine 2 to be controlled.
The control device 910 includes a position proportional control section 11 , a speed proportional integral control section 12 , a current control section 14 , a pseudo differentiating section 15 , a computing section 913 , a differentiation processing section 921 and an estimating section 922 . Functional units having the same functions as those of the control device 10 are denoted by the same reference numerals, and description thereof is omitted.

The controlled machine 2 includes a motor 21, a gear 22, and a table 23 as in FIG. An encoder (not shown) is attached to the motor 21 .

The differential processing unit 921 performs differential processing on encoded values (observed values) output by the encoder of the motor 21 (FIG. 1) of the controlled machine 2 to obtain the velocity.
Estimation unit 922 stores the friction model. The estimating unit 922 uses the velocity obtained by the differential processing unit 921 to estimate the frictional force by referring to the friction model. The estimation unit 922 outputs the estimated frictional force to the calculation unit 913 as the compensation torque command value τ′*.

The calculation unit 913 adds the compensation torque command value τ′* output by the estimation unit 922 to the torque command value τ* output by the speed proportional integral control unit 12 . The calculation unit 913 outputs the torque command value τ* after addition to the current control unit 14 .

Next, an example of analyzing the results of control of the controlled machine 2 by the control device 910 of this comparative example will be described.
FIG. 7 is a diagram showing an example of analysis of the results of control of the controlled machine 2 by the control device in the comparative example. In addition, in FIG. 7, the control is started at time 1. As shown in FIG.

FIG. 7(A) is the analysis result of the angle change with respect to time. In FIG. 7A, the horizontal axis is time [s] and the vertical axis is angle [deg].
Symbol g41 indicates the change in angle on the motor side. Symbol g42 indicates the change in angle on the load side. Symbol g43 indicates a change in reference angle in which the stick-slip phenomenon does not occur.

FIG. 7B is an analysis result of changes in angle error with respect to time. In FIG. 7B, the horizontal axis is time [s] and the vertical axis is angle error [deg].
Symbol g44 indicates the change in angle error on the motor side. Symbol g45 indicates the change in angle error on the load side.

FIG. 7(C) is an analysis result of changes in input torque with respect to time. In FIG. 7C, the horizontal axis is time [s] and the vertical axis is input torque [Nm].
Symbol g46 indicates a change in integrated torque. Symbol g47 indicates a change in friction compensation.

According to the comparative example, as shown in FIG. 7(B), the angle error between the motor side and the load side vibrates greatly between 1 second and 2 seconds, and the vibration continues after about 2 seconds. . As a result, the stick-slip phenomenon as shown in FIG. 8 continues to occur. FIG. 8 is a diagram showing an example of a stick-slip phenomenon. In FIG. 8, the horizontal axis is time [s] and the vertical axis is angle [deg]. Reference g51 indicates a target value, and reference g52 indicates an actually observed angle (actual angle).

In the comparative example, since the vibration of the angle error continues even after 2 seconds, as shown in FIG. It continues to vibrate with amplitude. Further, as shown in FIG. 7A, the angle between the motor side and the load side continues to oscillate even after about 2 seconds. In the change of the angle with respect to time, when the scale of the angle is enlarged, as shown in FIG. Note that FIG. 8 is not an enlarged view of the angular scale of FIG. 7, but merely an example of a stick-slip phenomenon.

On the other hand, in this embodiment, as shown in FIG. 5(C), the amplitudes of the integrated torque and friction compensation values after 2 seconds are almost 0, and there is no vibration. Further, in this embodiment, as shown in FIG. 5A, there is almost no angular vibration between the motor side and the load side after about 2 seconds. Thus, in this embodiment, the stick-slip phenomenon could be significantly suppressed as compared with the comparative example.

[Friction Compensation Filter Used in Compensator]
Next, an example of a friction compensation filter used in compensator 163 will be described.
First, the physical model of the machine to be controlled and the physical model of the friction compensator used to obtain the friction compensation filter will be described.

FIG. 9 is a diagram showing the controlled machine 2 and the friction compensator 16 according to this embodiment as a physical model. As shown in FIG. 9 , the controlled machine 2 is modeled by a combination of a transfer function for the motor 21 , a transfer function for the gear 22 and a transfer function for the table 23 . Note that reference numerals T11 to T15 denote calculation units that perform addition or subtraction.
Further, the symbol CP is a closed loop to which the torque command value τ* is input. Let the transfer function of this closed loop CP be P(s).

A transfer function for the motor 21 is defined by the moment of inertia J _M of the motor 21 and the viscosity coefficient D _M of the motor 21 .
The transfer function for gear 22 is defined by gear 22 moment of inertia J _d and gear 22 viscosity coefficient D _d .
The transfer function for table 23 is defined by table 23 moment of inertia J _L and table 23 viscosity coefficient D _L .

The transfer function T1 is defined by the stiffness coefficient _Kg of the connecting member that connects the motor 21 and the gear 22 .
The transfer function T2 is defined by the stiffness _coefficient KR of the connecting member that connects the gear 22 and the table 23 .

Furthermore, as shown in FIG. 9, the transfer function for the table 23 includes the first linear friction coefficient T3, which is one of the nonlinear components of the machine 2 to be controlled. The first linear friction coefficient T3 is a linear coefficient F which is a load friction model to be controlled. The first linear friction coefficient T3 has the characteristic of the frictional resistance T _fL generated by the table 23 according to the speed of the table 23 (observed table speed ω _L ), for example. The first linear friction coefficient T3 includes static friction generated when the table 23 is stationary and dynamic friction generated when the table 23 is in motion (dynamic friction has a smaller frictional resistance than static friction).

The differentiating unit 51 differentiates the observed value of the angle of the controlled machine 2 to obtain the velocity, and outputs the obtained velocity to the second linear friction coefficient 52 .
The second linear friction coefficient 52 is a control system load friction model and is assumed to be a linear coefficient _Fc . The second linear friction coefficient 52 uses a friction model to estimate and output a friction value corresponding to the speed input from the differentiating section 51 . The second linear friction coefficient 52 outputs the estimated friction value to the friction compensation filter 53 .

The friction compensation filter 53 is a filter for removing the influence of the linear coefficient _F and the linear coefficient FC on the transfer function P(s), and is a function G. In other words, the friction compensation filter 53 is a filter for canceling the effects of friction. This filter is used in compensator 163 .

It should be noted that the physical model of the controlled machine 2 shown in FIG. 9 merely explains that each drive mechanism (motor 21, gear 22, table 23, etc.) includes non-linear elements, mainly frictional characteristics. The physical model of the machine to be controlled 2 may be any model that corresponds to the machine to be controlled, and may be different.

Next, an example of how to obtain the friction compensation filter will be described.
The closed-loop transfer function P(s) in FIG. 9 is represented by the following equation (1).

In the formula (1), the numerator x is represented by the following formula (2), the denominator y is represented by the following formula (3),

In equation (3), the term F(-D _d D _g s ³ -...-K _g K _r s) is the term of the load friction model of the controlled object. The term _{Fc ( DgDrGs3} ⁺ _{DgGKrs2 + DrGKgs2} ^{+ GKgKrs} ₎ is a _term of the load friction model of the control system _. The term (D _g D _r Gs ³ +D _g GK _{rs 2 +D r} ^GK _{g s} ² +GK _g K _rs ) is a friction filter term.
When the numerator of the formula (2) is B ₁ (s), the following formula (4) is obtained.

In the denominator, if the term other than the term of the linear coefficient F, the term of Fc, and the term of the function G is A1, A1 is represented by the following equation ( ₅ ). Also, if (-D _d D g s ³ -... -K _g K _r s) in the term F (-D _d D _g s ³ _-... - K _g K _r s) is A2, then A ₂ is represented by the following equation (6). In addition, in the term of F _c (D _{g Dr} Gs ³ +D _g GK _rs ² +D _r GK _g s ² +GK _g K _rs ), (D _{g Dr} Gs ³ +D _g GK _rs ² +D _r GK _g s ² +GK _g K _r s) is bounded by a function G, which is a friction compensation filter, to form GA ₃ , A ₃ is expressed by the following equation (7).

Expression (1) using B ₁ , A ₁ , A ₂ , A ₃ , linear coefficient F, linear coefficient _Fc , and function G results in the following equation (8).

Assuming that the linear coefficient F and the linear coefficient _Fc are equal in Equation (8), Equation (8) can be replaced with Equation (9) below.

In order to cancel the term of the linear coefficient F in the equation (8), the function G should be the following equation (10).

Equation (10) is a non-proper transfer function, ie the numerator is of higher order than the denominator. For this reason, in this embodiment, the function G is further subjected to a third-order LPF (low-pass filter) as shown in the following equation (11) to make the order of the numerator smaller than that of the denominator.

In equation (11), the term 1/(τ _G s+1) ³ is the third-order LPF term. Also, _τG is a predetermined time constant in the LPF.
Further, in the formula (11), a ₁ ^' is the following formula (12), a ₂ ^' is the following formula (13), a ₃ ^' is the following formula (14), and a ₄ ^' is the following formula (15), and a ₅ ^' is the following equation (16).

In this embodiment, the function G (also referred to as the friction compensation filter G), which is the friction compensation filter, is obtained in this way.
Note that the friction compensation filter G in equation (11) is a value obtained by solving the physical model shown in FIG. Therefore, if the machine to be controlled is different and the physical model is different, the value of the friction compensation filter G will be different from that in equation (11). Even in this case, the friction compensation filter G is designed as a filter that cancels the effects of friction.

As described above, in this embodiment, in order to estimate the frictional force generated in the sliding portion, the speed is calculated from the encoded value attached to the load. Further, in this embodiment, the velocity value is referred to, and the currently acting friction force is estimated from the friction model and added to the control torque value. In addition, in this embodiment, the friction model is assumed to be a model that reproduces not only simple dynamic friction but also static friction and dynamic friction.
In this embodiment, the estimated friction force is added after compensating for the phase delay and phase lead of the characteristics from the motor to the load so that the influence of nonlinear friction disappears from the closed loop system.
Further, in this embodiment, nonlinear load friction, which is difficult to model, is linearized near the operating point, and a filter is designed to correct the influence of the internal inertial system. In addition, the effects of modeling errors due to linearization were reduced by compensating with feedback control.
In addition, in this embodiment, the direction in which friction is generated is predicted from the command value, and hunting is prevented by correcting the frictional force.

Thus, according to this embodiment, by applying an appropriate friction compensating force to the actuator, high positioning accuracy can be achieved.
Here, conventionally, there are mechanical elements that can be simulated in multiple inertia systems between the actuator and the actual sliding part (for example, reduction gear rigidity, shaft torsional rigidity in the case of a rotating system, translational In the case of a system, the ball screw rigidity used for translational transformation, etc.), these characteristics were corrected with a simple DC gain. However, in order to achieve high-precision friction compensation, the mechanical element characteristics should be precisely grasped and corrected, but conventional methods could not correct them.
In contrast, according to the present embodiment, the mechanical element characteristics can be accurately grasped and corrected in order to realize highly accurate friction compensation.

Further, according to the present embodiment, it is possible to realize highly accurate friction compensation by compensating for the frictional force in which the phase advance/phase delay included in the multi-inertia system is corrected.
Further, according to the present embodiment, even if an overshoot occurs during slippage, hunting (oscillation of the correction value) can be reduced by limiting the direction of friction compensation by the correction unit 164 . As described above, according to the present embodiment, the correction unit 164 corrects the output of the friction compensation value according to the angle command difference value Δθ _M *, thereby preventing the vibration caused by the stick-slip phenomenon from being promoted. can.

<Second embodiment>
In the first embodiment, the example in which the encoder is attached to the table 23 (FIG. 1), which is the load of the controlled machine 2, has been described. In this embodiment, an example in which an encoder (not shown) is attached to the motor 21 (FIG. 1) of the machine 2 to be controlled will be described.

FIG. 10 is a block diagram showing the functional configuration of the control device 10A according to this embodiment.
As shown in FIG. 10, the control device 10A includes a control section 101 and a friction compensation section 16A. The control device 10A controls the controlled machine 2 .
The control unit 101 includes a position proportional control unit 11 (command value acquisition unit, observation value acquisition unit), a velocity proportional integral control unit 12, a calculation unit 13, a current control unit 14, and a pseudo differentiation unit 15 (observation value acquisition unit). Prepare.
The friction compensator 16A includes a difference calculator 161 (command value acquirer), a friction calculator 162A (observed value acquirer), a compensator 163 and a corrector 164 .
The friction calculation section 162A includes a conversion section 1621A and a friction model storage section 1622A.
The compensation section 163 includes a friction compensation filter storage section 1631 .
Note that functional units having functions similar to those of the control device 10 are denoted by the same reference numerals, and description thereof is omitted.

The converter 1621A acquires an encoded value (observed value) output by an encoder (not shown) attached to the motor 21 (FIG. 1). The encoded value to be acquired is the motor angle, which is the rotation angle of the motor 21 ( FIG. 1 ) of the controlled machine 2 whose rotation angle changes under the control of the control unit 101 . The converter 1621A, for example, passes this motor angle through the transmission characteristic from the motor to the load to estimate the load speed. Then, the conversion unit 1621A, for example, refers to this load speed value and estimates the currently acting frictional force from the friction model. Note that the converter 1621A is designed by, for example, applying a notch filter to the transfer function of the speed of the load from the motor angle.

The friction model storage unit 1622A stores a finely modeled friction model such as a LuGre model or a GMS model. The LuGre model is a friction model obtained by extending the Dahl friction model. The GMS model is a friction model in which N blocks with different characteristics and springs are connected in parallel.

The friction calculation unit 162A uses the speed converted by the conversion unit 1621A to refer to the friction model stored in the friction model storage unit 1622, and obtains the friction amount corresponding to the speed, thereby obtaining an estimated friction value (correction command value). Ask for

After that, the processing of the compensator 163 and the corrector 164 is the same as that of the control device 10 .

The controlled machine 2 is often under semi-closed control without a sensor (encoder) on the load. In such a case, it is costly to implement a configuration in which the encoder is attached to the load. On the other hand, the motor 21 (FIG. 1) of the controlled machine 2 often has an encoder. With such a configuration, the configuration of the present embodiment is easier to implement than the configuration of the first embodiment, and there is no need to add an encoder, so there is no cost increase.
The results obtained with the configuration of this embodiment are the same as those of the configuration of the first embodiment.

As described above, in this embodiment, the influence of friction is canceled based on the output value of the encoder of the motor 21 (FIG. 1).
Thereby, in this embodiment, the same effects as those of the first embodiment can be obtained.

<Third Embodiment>
The control device 10 of the first embodiment or the control device 10A of the second embodiment may include a disturbance observer section.

FIG. 11 is a block diagram showing the functional configuration of the control device 10B according to this embodiment. FIG. 11 shows an example in which the present embodiment is applied to the control device 10A of the second embodiment. The functional units having the same functions as those of the control device 10A are denoted by the same reference numerals, and descriptions thereof are omitted.
As shown in FIG. 11, the control device 10B includes a control section 101B, a friction compensation section 16A, and a first disturbance observer section 17. As shown in FIG.
The control unit 101B includes the position proportional control unit 11 (command value acquisition unit, observation value acquisition unit), velocity proportional integral control unit 12, calculation unit 13B, current control unit 14, and pseudo differentiation unit 15 (observation value acquisition unit). Prepare.
The first disturbance observer section 17 includes a model storage section 171 .

The model storage unit 171 stores, for example, the physical model of the controlled machine 2 shown in FIG. 9 and the inverse model of the physical model of the controlled machine 2 . The model storage unit 171 stores a physical model obtained by simplifying the physical model of the controlled machine 2 shown in FIG. 9 and an inverse model of the simplified physical model of the controlled machine 2 . A simplified physical model of the controlled machine 2 is a model including, for example, two of the motor 21 (FIG. 1), the gear 22 (FIG. 1), and the table 23 (FIG. 1).

The first disturbance observer unit 17 acquires the torque command value τ* (control signal) output by the speed proportional integral control unit 12 and the motor speed observation value ω _M output by the pseudo differentiation unit 15 . The first disturbance observer unit 17 inputs the torque command value τ* to the physical model of the controlled machine 2 stored in the model storage unit 171 to obtain the speed. The first disturbance observer unit 17 obtains a speed difference between the obtained speed and the motor speed observed value _ωM . The first disturbance observer unit 17 inputs the obtained speed difference to the inverse model of the physical model of the controlled machine 2 stored in the model storage unit 171 to obtain the correction value ε. The first disturbance observer section 17 outputs the correction value ε to the calculation section 13B.

The calculation unit 13B combines the torque command value τ* output by the speed proportional integral control unit 12 with the corrected torque command value Δτ* output by the correction unit 164 of the friction compensation unit 16 and the first disturbance observer unit 17. and the correction value ε. The calculation unit 13B outputs the torque command value τ* after addition to the current control unit 14 . In other words, this correction value ε is a torque command that cancels the response difference, which is the difference between the command value and the observed value.

By modeling the friction model in detail, it becomes possible to perform friction compensation with higher accuracy than before. However, it has low robustness and may lead to deterioration of accuracy when applied in a small nonlinear range.
Therefore, in this embodiment, the first disturbance observer section 17 is further provided.

Thus, in this embodiment, the nonlinear component can be compensated for by the correction value ε obtained by the first disturbance observer section 17 . It should be noted that the delay caused by the disturbance observer (waste time due to compensation after receiving the signal) can be dealt with by the feedforward issuing a command in advance. Thus, in this embodiment, nonlinear characteristics such as stick-slip can be compensated for by the synergistic effect of the combination of the two.
Even if the control device 10 described in the first embodiment further includes the first disturbance observer section 17, similar effects can be obtained.

<Fourth Embodiment>
3rd Embodiment demonstrated the example which correct|amends a torque command value with the correction value which the 1st disturbance observer part 17 (FIG. 11) produced|generated. In this embodiment, an example in which the feedforward correction amount is sequentially updated based on the correction value ε generated by the disturbance observer unit will be described. This embodiment can also be applied to the control device 10 of the first embodiment or the control device 10A of the second embodiment.

FIG. 12 is a block diagram showing the functional configuration of the control device 10C according to this embodiment. FIG. 12 shows an example in which the present embodiment is applied to the control device 10A of the second embodiment. The functional units having the same functions as those of the control device 10A are denoted by the same reference numerals, and descriptions thereof are omitted.
As shown in FIG. 12, the control device 10C includes a control section 101, a friction compensation section 16C, and a second disturbance observer section 17C (or a third disturbance observer section 17D). The second disturbance observer section 17C (or the third disturbance observer section 17D) has a model storage section 171 .
The control unit 101 includes a position proportional control unit 11 (command value acquisition unit, observation value acquisition unit), a velocity proportional integral control unit 12, a calculation unit 13, a current control unit 14, and a pseudo differentiation unit 15 (observation value acquisition unit). Prepare.
The friction compensator 16C includes a difference calculator 161 (command value acquirer), a friction calculator 162C (observed value acquirer), a compensator 163C, and a corrector 164 .
The friction calculation unit 162C includes a conversion unit 1621 and a friction model storage unit 1622.
The compensator 163</b>C includes a friction compensation filter storage unit 1631 .

A second disturbance observer unit 17C acquires the torque command value τ* output by the speed proportional integral control unit 12 and the motor speed observation value ω _M output by the pseudo differentiation unit 15 . The second disturbance observer unit 17C inputs the torque command value τ* to the physical model of the controlled machine 2 stored in the model storage unit 171 to obtain the speed. The second disturbance observer unit 17C obtains a speed difference between the obtained speed and the motor speed observed value _ωM . The second disturbance observer unit 17C inputs the obtained speed difference to the inverse model of the physical model of the controlled machine 2 stored in the model storage unit 171 to obtain the correction value ε. The second disturbance observer section 17C outputs the correction value ε to the friction calculation section 162C. The third disturbance observer section 17D will be described later.

The friction calculation unit 162C uses the speed converted by the conversion unit 1621 to refer to the friction model stored in the friction model storage unit 1622 to obtain the friction amount corresponding to the speed, thereby obtaining the estimated friction value (correction command value ). The friction calculator 162C obtains the feedforward correction amount K using the correction value ε output by the second disturbance observer 17C. For example, the friction calculator 162C obtains the feedforward correction amount K by K=(1+ε/E) (where E is a constant). The feedforward correction amount K is, for example, gain. The friction calculation unit 162C sequentially updates the estimated friction value (correction command value) by multiplying the obtained estimated friction value by a feedforward correction amount K (eg, 1, 1.1, 1.2, . . . ).
For example, the friction calculation unit 162C increases K on the assumption that the larger the correction value ε, the greater the frictional disturbance and the insufficient compensation. Conversely, when the correction value ε is small, the friction calculation unit 162C considers that the friction is sufficiently compensated and brings K close to 1, which is the default.

As described above, in the present embodiment, the feedforward correction amount K is sequentially updated based on the correction value ε of the second disturbance observer section 17C.
The correction value ε by the second disturbance observer unit 17C indicates the disturbance estimation error. A large estimation error means a large amount of friction, so in the present embodiment, the feedforward correction amount is increased to correct this. Correction is also possible with an observer, but correction is delayed if the observer band cannot be increased due to mechanical characteristics such as resonance of the machine 2 to be controlled. In such a case, feedforward correction can reduce the delay, so that the nonlinear characteristics can be compensated immediately.

In addition, although the example mentioned above demonstrated the example which updates the feedforward correction amount K of 162 C of friction calculating parts one by one, it does not restrict to this. For example, the friction calculation unit 162C may vary the parameters of the physical model described with reference to FIG. 9 based on the correction value ε. good too.

Furthermore, the feedforward correction amount K' of the compensator 163C may be updated sequentially. In this case, the third disturbance observer section 17D may output the correction value ε to the compensation section 163C without outputting it to the friction calculation section 162C.

The compensation unit 163C uses the friction compensation filter stored in the friction compensation filter storage unit 1631 to adjust the phase delay and phase lead of the multi-inertia system with respect to the friction estimated value (correction command value) output by the friction calculation unit 162C. A friction compensation value (correction command value) to be compensated is obtained. The compensator 163C may obtain the feedforward correction amount K' using the correction value ? output by the third disturbance observer 17D. For example, the compensator 163C may obtain the feedforward correction amount K' by K'=(1+ε/E') (where E' is a constant). The compensation unit 163C multiplies the obtained friction compensation value by a feedforward correction amount K' (eg, 1, 1.1, 1.2, . . . ) to sequentially update the friction compensation value (correction command value). may

The compensator 163C may vary the parameters of the physical model described with reference to FIG. 9 based on the correction value ε.

In each of the above-described embodiments, the machine 2 to be controlled is a machine including the motor 21, the gear 22, and the table 23 as shown in FIG. Not exclusively. The machine 2 to be controlled may be, for example, a robot having a six-axis manipulator, and the control device 10 (or 10A, 10B, 10C) may control the angle of each joint and each speed. Also, the machine 2 to be controlled may be a device that has strong nonlinear elements such as stick-slip and causes positioning control deviation.

In each of the embodiments described above, an example in which the control device 10 (or 10A, 10B, or 10C) includes the compensator 163 (or 163C) and the corrector 164 has been described, but the present invention is not limited to this. The control device 10 (or 10A, 10B, 10C) does not have to include the corrector 164 . Even in this case, it is possible to compensate for phase lag and phase lead in the control loop.
Also, the control device 10 (or 10A, 10B, 10C) does not have to include the compensator 163 (or 163C). Even in this case, the correction unit 164 corrects the output of the friction compensation value according to the angle command difference value Δθ _M *, so that the vibration due to the stick-slip phenomenon can be prevented from being promoted.

A program for realizing all or part of the functions of the control device 10 (or 10A, 10B, 10C) in the present invention is recorded on a computer-readable recording medium, and the program recorded on this recording medium is executed by a computer. All or part of the processing performed by the control device 10 (or 10A, 10B, 10C) may be performed by loading and executing the system. "Computer system" shall also include a WWW system equipped with a homepage providing environment (or display environment).In addition, "computer-readable recording medium" shall include flexible discs, optical It refers to portable media such as magnetic disks, ROMs, CD-ROMs, and storage devices such as hard disks built into computer systems.In addition, "computer-readable recording media" refers to networks such as the Internet, telephone lines, etc. It also includes a volatile memory (RAM) inside a computer system that serves as a server or a client when the program is transmitted via the communication line of (1), which holds the program for a certain period of time.

Further, the above program may be transmitted from a computer system storing this program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in a transmission medium. Here, the "transmission medium" for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. Further, the program may be for realizing part of the functions described above. Furthermore, it may be a so-called difference file (difference program) that can realize the above-described functions in combination with a program already recorded in the computer system.

As described above, the mode for carrying out the present invention has been described using the embodiments, but the present invention is not limited to such embodiments at all, and various modifications and replacements can be made without departing from the scope of the present invention. can be added.

1... machine tools,
10, 10A, 10B, 10C... control device,
2 ... machine to be controlled,
101, 101B...control unit,
11 ... position proportional control unit (command value acquisition unit, observation value acquisition unit),
12... Velocity proportional integral control section,
13, 13B... calculator,
14 ... current control unit,
15 Pseudo differential unit (observed value acquisition unit),
16, 16A, 16C...friction compensator,
161 ... Difference calculation unit (command value acquisition unit),
162, 162A, 162C ... friction calculation unit (observation value acquisition unit),
163, 163C... compensator,
164 ... correction unit,
1621, 1621A ... conversion unit,
1622, 1622A ... friction model storage unit,
1631 ... friction compensation filter storage unit,
17 ... the first disturbance observer section,
17C ... second disturbance observer section,
17D ... third disturbance observer section,
171 ... model storage unit,
21... motor,
22 gear,
23 ... table,
θ _M *... motor position command value,
θ _M … Observed motor position,
ω _M *... motor speed command value,
ω _M … motor speed observed value,
τ*: Torque command value,
Δτ*: corrected torque command value,
τ…Torque,
Δθ _M * ... angle command difference value,
P(s): closed-loop transfer function,
F, F _C … linear coefficients,
J _M … Moment of inertia of the motor,
D _M … viscosity coefficient of the motor,
J _d … moment of inertia of gear,
D _d … gear viscosity coefficient,
J _L … moment of inertia of the table,
D _L … viscosity coefficient of the table,
K _g … Rigidity coefficient of the connecting member that connects the motor and the gear,
K _R … Rigidity coefficient of the connecting member that connects the gear and the table,
G ... function (friction compensation filter),
ω _L … Table velocity observed value,
T _fL … Frictional resistance,
K, K' ... feedforward correction amount,
ε…Correction value

Claims (11)

a command value acquisition unit that acquires a command value for the machine to be controlled;
an observation value acquisition unit that acquires an observation value for the machine to be controlled;
a control unit that controls the controlled machine so as to eliminate the difference between the command value and the observed value;
a friction calculation unit that calculates a frictional force acting on the controlled machine based on the observed value and a friction model applied to the controlled machine;
a compensating unit for compensating for a phase shift with the controlled machine in a control loop with respect to the frictional force and correcting the command value;
with
The observed value is a motor angle, which is the rotation angle of the motor of the controlled machine whose rotation angle changes under the control of the control unit;
The friction calculation unit uses the transfer function of the controlled machine and a notch filter to convert the motor angle into a movement speed of the load of the controlled machine whose position changes under the control of the control unit.
Control device. 2. The control device according to claim 1, further comprising a correction unit that corrects said command value further based on the direction of movement of said controlled machine indicated by said command value. The observed value further includes a position parameter of the load of the controlled machine whose position changes under the control of the control unit,
3. The control device according to claim 1, wherein the friction calculation unit further differentiates the position parameter of the load to convert it into a moving speed of the load in the machine to be controlled. The speed of the controlled machine is obtained based on the deviation between the command value and the observed value and a physical model applied to the controlled machine, and the The control device according to any one of claims 1 to 3, further comprising a first disturbance observer section that corrects the command value. A speed of the controlled machine is determined based on the deviation between the command value and the observed value and a physical model corresponding to the controlled machine, and a correction value is based on the deviation between the determined speed and the value based on the observed value. and a second disturbance observer unit that outputs the generated correction value to the friction calculation unit,
The control device according to any one of claims 1 to 4, wherein the friction calculation section updates the obtained friction force based on the correction value output by the second disturbance observer section. A speed of the controlled machine is obtained based on the deviation between the command value and the observed value and a physical model corresponding to the controlled machine, and a correction value is calculated based on the deviation between the speed obtained and the value based on the observed value. A third disturbance observer unit that generates and outputs the generated correction value to the compensation unit,
The control device according to any one of claims 1 to 4, wherein the compensation section corrects the command value based on the correction value output by the third disturbance observer section. a command value acquisition unit that acquires a command value for the machine to be controlled;
an observation value acquisition unit that acquires an observation value for the machine to be controlled;
a control unit that controls the controlled machine so as to eliminate the difference between the command value and the observed value;
a friction calculation unit that calculates a frictional force acting on the controlled machine based on the observed value and a friction model corresponding to the controlled machine;
a correction unit that corrects the value based on the frictional force based on the movement direction of the controlled machine indicated by the command value to correct the command value;
with
The observed value is a motor angle, which is the rotation angle of the motor of the controlled machine whose rotation angle changes under the control of the control unit;
The friction calculation unit uses the transfer function of the controlled machine and a notch filter to convert the motor angle into a movement speed of the load of the controlled machine whose position changes under the control of the control unit.
Control device. a command value acquiring unit acquiring a command value for the machine to be controlled;
an observed value acquisition unit configured to acquire an observed value of the machine to be controlled;
a step in which a control unit controls the controlled machine so as to eliminate the difference between the command value and the observed value;
a friction calculation unit obtaining a frictional force acting on the controlled machine based on the observed value and a friction model applied to the controlled machine;
a step in which a compensator compensates for a phase shift with the controlled machine in a control loop with respect to the frictional force to correct the command value;
including
The observed value is a motor angle, which is the rotation angle of the motor of the controlled machine whose rotation angle changes under the control of the control unit;
In the step of obtaining the frictional force, the motor angle is converted into a movement speed of the load of the controlled machine whose position changes under the control of the control unit, using a transfer function of the controlled machine and a notch filter.
control method. a command value acquiring unit acquiring a command value for the machine to be controlled;
an observation value acquisition unit acquiring an observation value for the machine to be controlled;
When the control unit controls the controlled machine so as to eliminate the difference between the command value and the observed value,
a friction calculation unit obtaining a frictional force acting on the controlled machine based on the observed value and a friction model corresponding to the controlled machine;
a step in which a correction unit corrects the command value by correcting the value based on the frictional force based on the movement direction of the controlled machine indicated by the command value;
including
The observed value is a motor angle, which is the rotation angle of the motor of the controlled machine whose rotation angle changes under the control of the control unit;
In the step of obtaining the frictional force, the motor angle is converted into a movement speed of the load of the controlled machine whose position changes under the control of the control unit, using a transfer function of the controlled machine and a notch filter.
control method. In the computer of the control device that controls the machine to be controlled,
obtaining a command value for the machine to be controlled;
an observation value acquisition unit that acquires an observation value for the machine to be controlled;
controlling the controlled machine so as to eliminate the difference between the command value and the observed value;
obtaining a frictional force acting on the controlled machine based on the observed value and a friction model applied to the controlled machine;
a step of compensating for a phase shift with the controlled machine in a control loop with respect to the frictional force to correct the command value;
A program that executes
The observed value is a motor angle, which is the rotation angle of the motor of the controlled machine whose rotation angle is changed by the control in the step of controlling the controlled machine,
In the step of obtaining the frictional force, the movement speed of the load of the controlled machine whose position is changed by the control in the step of controlling the controlled machine from the motor angle using the transfer function and the notch filter of the controlled machine. convert to,
program. In the computer of the control device that controls the machine to be controlled,
obtaining a command value for the machine to be controlled;
obtaining observations about the controlled machine;
When the controlled machine is controlled to eliminate the difference between the command value and the observed value,
obtaining a frictional force acting on the controlled machine based on the observed value and a friction model corresponding to the controlled machine;
a step of correcting the command value by correcting the value based on the frictional force based on the movement direction of the controlled machine indicated by the command value;
A program that executes
The observed value is a motor angle, which is the rotation angle of the motor of the controlled machine whose rotation angle is changed by the control in the step of controlling the controlled machine,
In the step of obtaining the frictional force, the movement speed of the load of the controlled machine whose position is changed by the control in the step of controlling the controlled machine from the motor angle using the transfer function and the notch filter of the controlled machine. convert to,
program.

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