WO2019087554A1

WO2019087554A1 - Feedback control method and motor control device

Info

Publication number: WO2019087554A1
Application number: PCT/JP2018/032336
Authority: WO
Inventors: 満松原; 山崎　勝; 裕理高野; 雄介上井; 哲男梁田
Original assignee: 株式会社日立産機システム
Priority date: 2017-10-30
Filing date: 2018-08-31
Publication date: 2019-05-09
Also published as: JP6979330B2; JP2019082791A

Abstract

An objective of the present invention is to provide a feedback control method involving a lag compensator appropriate for implementation and a motor control device using said feedback control method such that computation costs can be reduced for the lag compensator which is capable of reducing step disturbances added to the input end of a plant without leaving errors even if the plant has a pole at the origin. To achieve the objective, provided is a lag compensator 1 which comprises a feedback controller 1, a filter 1, and a model of a plant, receives the output of a feedback controller 2 and a response by the plant as input, and outputs a feedback signal for the controller 2, wherein the lag compensator 1 produces as a manipulation quantity 1 a signal obtained by adding the output of the controller 1 and the output of the controller 2, subtracts an output of the model of the plant in response to the manipulation quantity 1 from the response of the plant to obtain an error signal 1 to be used as the input for the controller 1, and adds a signal resulting from passing the error signal 1 through the filter to the response of the nominal plant model to the manipulation quantity to produce the output signal.

Description

Feedback control method and motor control device

The present invention relates to a feedback control method and a motor control device provided with the control method.

In recent years, in the field of FA, there has been a demand for increasingly faster and more accurate control of motors to improve productivity.

When feedback control of the motor is performed, the control gain may be increased in order to suppress the disturbance and make the control amount follow the target value at high speed with high accuracy. However, when there is a delay element (for example, an operation delay of a low pass filter or digital controller) in the feedback loop, the upper limit of the control gain of the feedback control system is restricted due to this, and high speed / high accuracy target value tracking It is generally known to be a hindrance.

As a method of designing a delay compensator which can compensate for a delay element existing in a closed loop of a feedback control system even when the control target has a pole at the origin and can suppress step disturbances applied to the input end of the control target without steady deviation. Patent Document 1 is proposed.

In Patent Document 1, as shown in FIG. 6, in the delay compensator 62 (corresponding to the conventional Smith method with N = 1) in which the filter 61 is added to the Smith method of the prior art, the control target has a pole at the origin A method of designing the filter 61 is shown, which is characterized in that even if it has the step disturbance applied to the input end of the control object can be suppressed without steady-state deviation and the physical meaning of the design parameter of the filter 61 can be easily understood. . By adopting the filters 61 of various configurations designed by this design method as the delay compensator 62, it is possible to design various delay compensators 62 having the above-mentioned features.

Japanese Patent Application No. 2017-054595

In patent document 1, the structure of Formula (1) shown below and Formula (2) is mentioned as a design example of the filter 61 shown in FIG.

However, Pm is a nominal plant model 14 to be controlled, Cb (θ 1) has θ 1 as an adjustment parameter, a feedback controller 16 capable of suppressing the deviation between the target value and the control target response, and τ m is included in the control object 12 The model value of the sum of the delay time τf and the delay time τb included in the feedback delay element 13, exp (−τm · s), is a nominal delay element model 15 with the delay time τm.

Further, Ca is an optional feedback controller that effectively functions with respect to the control target, and in the case where Ca has the same structure as the feedback controller Cb, Ca is determined as shown in equation (3).

However, the filter 61 represented by the equation (1) and the equation (2) includes exp (-. Tau.m.s) in the denominator, and, of course, when exp (-. Tau.m.s) is calculated strictly Even in the case of approximation by a low order transfer function using the Pade approximation method or the like, the order of the transfer function of the filter represented by the equations (1) and (2) tends to be high.

Therefore, for example, when the filter 61 of the delay compensator 62 shown in FIG. 6, which is designed in Patent Document 1 shown by Equation (1) and Equation (2), is mounted on hardware such as a digital arithmetic device, hardware There is a problem that the calculation cost for the above filter processing is high.

The present invention has been made in view of such problems, and for example, a delay compensator 62 including the filter 61 shown by the equations (1) and (2), which is designed by the design method of Patent Document 1, It is an object of the present invention to provide a control method suitable for mounting, and a control device including the same, which can reduce the calculation cost of hardware of the filter 61 of the delay compensator 62 when mounting on hardware such as a digital arithmetic device. I assume.

In view of the above background art and problems, the present invention is a feedback control method including a delay compensator 1 including a model of an object to be controlled, an optional filter 1 and an optional feedback controller 1 in an example. The model of the control target includes a nominal plant model that simulates the dynamics of the control target and a nominal delay model that simulates a delay element included in the closed loop of the feedback control system, and the delay compensator 1 controls The manipulated variable output by the feedback controller 2 that performs feedback control on the object and the output signal of the controlled object are input signals, and the manipulated variable and the output of any feedback controller 1 included in the delay compensator 1 are added / subtracted Output signal of the nominal plant model to the signal added by A signal obtained by subtracting the output signal of the model to be controlled with respect to the signal obtained by adding the output of an arbitrary feedback controller 1 included in the compensator 1 by the adder / subtracter and the output signal of the control target by the adder / subtracter A model error signal is input to an arbitrary feedback controller 1, and a signal obtained by processing the model error signal by an arbitrary filter 1 and an ideal feedback signal is added to an output signal as an output signal. The feedback controller 2 calculates the deviation between the output signal of the delay compensator 1 and the target value signal with an adder / subtractor, and performs feedback compensation on the control target based on the deviation.

According to the present invention, it is possible to provide a feedback control method suitable for implementation that can reduce the operation cost in hardware implementation, and a motor control apparatus including the same.

FIG. 6 is a configuration diagram of a model following control system in Example 1 (A (s) = 1). FIG. 2 is a configuration diagram of a model following control system in Embodiment 1. FIG. 2 is a block diagram of a feedback control system including a delay compensator in the first embodiment. FIG. 5 is a configuration diagram (A (s) = 1) of a feedback control system including a delay compensator in the first embodiment. FIG. 7 is a configuration diagram (A (s) = γ) of a feedback control system including a delay compensator in the first embodiment. It is a block diagram of the feedback control system containing the delay compensator by a prior art. It is a block diagram of the speed control system of an AC servomotor. It is a block diagram of the speed feedback control system containing the delay compensator in a prior art. FIG. 7 is a block diagram of a speed feedback control system including a delay compensator in a second embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, components having common functions are assigned the same reference numerals and descriptions thereof will be omitted. Also, hereinafter, "feedback" is abbreviated as "FB". For example, "feedback controller is abbreviated as" FB controller ". "Feed forward" is abbreviated as "FF". For example, “feed forward controller” is abbreviated as “FF controller”.

In the motor control method according to the present embodiment and the motor control device provided with the same, as shown in FIG. 3, an FB control system including the delay compensator 2 and the FB controller 16 with respect to the control object 12 including a delay. Shall be configured.

In FIG. 3, CA and A (s) are optional FB controllers 3 and filters 1 that function effectively for the control target. In this embodiment, in order to derive the compensation performance equivalent to the delay compensator 62 shown in FIG. 6 having the filter 61 (for example, the above-mentioned equations (1) and (2)) designed in Patent Document 1 It is suitably configured.

The delay compensator 2 includes an FB controller 3, a filter 1, and a model of a control target. In the present embodiment, the model to be controlled consists of a nominal plant model 14 and a nominal delay element model 15, which simulates the dynamic characteristics of the control object 12 to be actually controlled and the FB delay element 13. It is. That is, the model of the control target includes a nominal plant model that simulates the dynamics of the control target, and a nominal delay model that simulates a delay element included in the closed loop of the feedback control system.

When an element generating delay is included in the closed loop system, such as a filter or a minor loop control system, the model of the control target may include a nominal model of the delay elements.

Hereinafter, the transfer characteristic in which the control target 12 and the FB delay element 13 are connected in series may be simply referred to as a control target.

The delay compensator 2 has as inputs the manipulated variable output by the FB controller 16 and the output of the controlled object with respect to the manipulated variable output by the FB controller 16, and outputs an FB signal with respect to the target value r.

The operation of the delay compensator 2 will be described based on FIG. The delay compensator 2 is an operation in which the FB controller 16 outputs a response of a model to be controlled to a signal obtained by adding the output of an arbitrary FB controller 3 and the manipulated variable output by the FB controller 16 by the adder / subtractor 4 A model error signal is calculated by subtracting at the adder / subtractor 39 from the response output of the control object with respect to the quantity.

Further, the delay compensator 2 calculates a response of the plant nominal model 14 to a signal obtained by adding the output of an arbitrary FB controller 3 and the manipulated variable output by the FB controller 16 by the adder / subtractor 4 as a predicted FB signal, The signal obtained by processing the model error signal by the filter 1 and the predicted FB signal are added by the adder / subtractor 35 and output as an FB signal with respect to the target value r.

The FB controller 16 receives a deviation signal obtained by subtracting the FB signal output from the delay compensator 2 from the target value r by the adder / subtractor 37, and generates an operation amount for the control target.

In the FB control system including the delay compensator 2 shown in FIG. 3, it is assumed that the adder / subtractor 18 is located at the input end of the control target, and the disturbance d is added to the input end of the control target.

When the delay compensator is configured by the generally known Smith method (in the case of the delay compensator 62 where N = 1 in FIG. 6), the step added to the input end of the control target when the control target has a pole at the origin There is a problem that the disturbance can not be suppressed without steady-state deviation. On the other hand, in the case of the delay compensator 62 designed by Patent Document 1, for example, employing the filter N of Equations (1) and (2), the step disturbance applied to the control target input end is suppressed without steady deviation. be able to.

The delay compensator 2 shown in FIG. 3 in the present embodiment has a compensation performance equivalent to that of the delay compensator 62 which is, for example, the filter N of the equations (1) and (2). It is designed.

For this purpose, CA and A (s) of the delay compensator 2 are designed, for example, as in the following formulas (4) and (5).

However, Ca indicates an optional feedback controller that functions effectively for the control object, used in the design of the filter 61 of the delay compensator 62 shown in FIG.

The delay compensators designed as equations (4) and (5) correspond to the delay compensator 42 of FIG. 4, and the input / output characteristics of the delay compensator 42 are expressed by equation (1) from simple calculation The input / output characteristics are equivalent to the delay compensator 62 shown in FIG. 6 including the filter N. This is explained below.

The input / output characteristics of the delay compensator 62 shown in FIG.

On the other hand, the input / output characteristics of the delay compensator 42 of FIG. 3 can be written as Expression (9) by arranging the following equations (7) and (8) derived from FIG. 3 with respect to the input and output.

Formula (9) becomes equal to Formula (6) by setting Formula (4), (5). Therefore, with respect to the delay compensator 2 of FIG. 3, the delay compensator 42 designed as the equations (4) and (5) has the delay compensation of FIG. 6 including the filter N shown in the equation (1). It can be seen that the device 62 is equivalent to the input / output characteristic.

Further, CA and A (s) of the delay compensator 2 are designed, for example, as in the following formulas (10) and (11).

The delay compensator 2 designed as the equations (10) and (11) includes the filter N shown in the equation (2) by the equation expansion similar to the equations (6) to (9). It can be confirmed that the input / output characteristics are equivalent to the delay compensator 62 of FIG.

In all of Equations (4) to (5) and Equations (10) to (11), the transfer characteristic Pm of the nominal plant model 14 and the nominal delay element model 15 included in Equations (1) and (2) It can be seen that the transfer function is a simple transfer function that does not include the transfer characteristic exp (−τm · s).

The reason why the transfer functions of CA and A (s) are simplified as compared with equations (1) and (2) is the reason why Pm and exp (-) included in equations (1) and (2) This is because the delay compensator 2 is configured as a block configuration that can share the calculation of τm · s) with the calculation of the nominal plant model 14 and the nominal delay element model 15 in the figure.

Next, the characteristics of the delay compensator 2 shown in FIG. 3 will be described using FIGS. The command value response r → y and the disturbance response d → y in FIGS. 1 and 2 are equivalent to the command value response r → y and the disturbance response d → y shown in FIGS. 4 and 3, respectively, that is, FIG. FIG. 2 shows a control system whose response is equivalent to that of FIGS. 4 and 3, respectively. Further, FIG. 1 shows the case where A (s) = 1 in FIG.

First, the characteristics of the delay compensator 2 will be described based on FIG. In FIG. 1, the transfer characteristic of rs → y is given by the reference model type real FB control system 7. In order to simplify the explanation below, it is assumed that there is no disturbance and d = 0. However, it should be noted that even if d 説明 0, the following description is true.

A model FB control system 8 is configured as shown in FIG. 1 using the nominal plant model 14, the nominal delay element model 15, and the FB controller CA3. In the model FB control system 8, y corresponds to a command, and u can be regarded as an FF manipulated variable in the response rs → ym. Therefore, the model FB control system 8 is configured to follow the response y of the reference model type real FB control system 7 having a transfer characteristic of rs → y, and is configured as a model following type two degree of freedom control. Therefore, the FB controller Cb plays the role of an FF controller by setting the model response ym to an ideal response that matches the actual response y to a high response, and the FB controller CA performs the model response ym and the actual response y. Play a role in compensating for deviations from The FB controller CA can be designed so as to stably and robustly suppress the deviation y-ym independently of the FB controller Cb from the viewpoint of two-degree-of-freedom control.

As a result, the controller configuration of FIG. 1 can realize the model response ym-the actual response y → 0 with high response, stability and robustness.

Further, in FIG. 1, when CA = 0, this is equivalent to the commonly known Smith method (when N = 1 in FIG. 6).

Yi shown in FIG. 1 is the predicted FB signal described in FIG. 3, and its role does not change even in the Smith method with CA = 0. The Smith method compensates for the delay by canceling the actual response y including the delay with the model response ym and driving the FB controller Cb based on the predicted FB signal yi not including the delay. At this time, when the control target has a pole at the origin, or when the control target is unstable, it is difficult to offset the actual response y by the model response ym. It is considered difficult to apply when there is a pole in the case or when the controlled object is unstable.

Also in the controller configuration of this embodiment, the adder-subtractor 5 and the adder-subtractor 6 form ym-y, and the FB controller Cb performs the FB control based on the command value r-predicted FB signal yi. The idea of is the same as the Smith method. However, as described above, the controller configuration of this embodiment can realize the model response ym-the actual response y → 0 in a high response, stably and robustly. Therefore, the controller configuration of the present embodiment can be regarded as having improved the cancellation of the actual response y due to the model response ym, which is the drawback of the Smith method, by adopting the configuration of the model following type of two degree of freedom control.

In FIG. 2 which is a control system equivalent to FIG. 3, an arbitrary filter A (s) processes the FB signal of the reference model type real FB control system 27, and an arbitrary filter A (s) processes a model response. The processing results are sent to the adder / subtractor 6. That is, the model response ym-the actual response y is processed by an arbitrary filter A (s), and the cancellation characteristic of canceling the actual response y by the model response ym can be adjusted by an arbitrary filter A (s) is there. However, when A (s) ≠ 1, the model response ym and the actual response y need to be separately filtered with A (s) in the configuration of FIG. 2, which is not advantageous in terms of calculation cost. In this case, the configuration shown in FIG. 3, which is a transfer characteristic equivalent to that of FIG. 2, is employed. In the configuration of FIG. 3, the filter A (s) is calculated only once for the model response ym−the actual response y, and duplication of the calculation cost for A (s) can be avoided. Therefore, when A (s) ≠ 1, adopting the configuration of FIG. 3 is advantageous over the configuration of FIG. 2 in terms of calculation cost.

From the above, with respect to the filter N designed in Patent Document 1, for example, when N shown in Formula (1) and Formula (2) is adopted, it is mounted by the configuration of FIG. 1 or FIG. The operation cost can be reduced more than that of the configuration shown in FIG. Also, FIG. 1 or FIG. 3 is configured as shown in FIG. 1 or FIG. 3 because it constitutes a configuration of model following type of two degree of freedom control and can realize model response ym-actual response y → 0 with high response and stability and robustness. For example, it is possible to improve the cancellation of the actual response y due to the model response ym, which is a drawback of the Smith method, and to compensate the delay with high response and stability even when the controlled object has a pole at the origin. It is.

Next, how much the calculation cost can be reduced by the delay compensator 2 of the present embodiment shown in FIG. 3 compared to the conventional delay compensator 62 will be described using a simple example.

In the FB control system shown in FIG. 6, it is assumed that the filter 61 adopts the one represented by the equation (1). An equivalent FB control system is an FB control system including the delay compensator 42 shown in FIG. 4 as described above. The FB controller Cb is a PI controller, and the FB controller Cb can adjust the control response at the response frequency ωb as shown in the following equation (12).

However, N is any positive real number.

Further, for the sake of simplicity, it is assumed that the transfer characteristic of the nominal delay element model 15 is approximated by Pade approximation (first order) as shown in the following equation (13).

Furthermore, it is assumed that any FB control Ca included in the equation (1) has the same structure as the FB controller Cb. That is, it is assumed that the FB controller Ca can adjust the controllability independently of ωb at the response frequency ωa, under the assumption of the equation (3).

Under the above assumption, the filter of equation (1) becomes the following equations (14), (15) and (16).

In FIG. 6, when the model error signal ye is obtained from the operation amount u of the FB controller 16 and the output of the control object, the output yb of the delay compensator 62 is calculated by the following equation (17).

On the other hand, on the premise that the output of the FB controller 3 is already calculated as the previous state quantity in FIG. 4, a model error signal ye is obtained from the manipulated variable u of the FB controller 16 and the output of the control target In this case, the output yb of the delay compensator 2 is calculated by the following equation (18).

Comparing the equations (17) and (18), the second term on the right side is different, and the second term on the right side of the equation (18) has a lower order of the transfer function. Therefore, it can be understood that the calculation cost for calculating the output signal yb is lower in the delay compensator 42 of this embodiment than in the conventional delay compensator 62.

In this example, the Pade approximation is a first-order, but in the case of a higher-order Pade approximation, the order of the transfer function of the second term on the right side of the equation (17) is increased. It can be seen that the reduction of computational cost is more effective.

Even if the filter N is a filter N other than the formulas (1) and (2) designed in Patent Document 1, it is shown in FIG. 3 when the filter N is designed as one that can be expressed as the following formula (19). The configuration of the delay compensator 2 can realize a compensation characteristic equivalent to that of the delay compensator 62 shown in FIG. 6, and can reduce the operation cost more than the delay compensator 62 shown in FIG.

For example, the filter A (s) of the delay compensator 2 of FIG.

And the constant γ, the delay compensator 52 shown in FIG. 5 is obtained. Although proof is omitted, even in this configuration, it is possible to suppress the step disturbance applied to the input end of the control target without steady-state deviation when the control target has a pole at the origin.

As described above, according to this embodiment, the delay compensator 2 shown in FIG. 3 can exhibit compensation performance equivalent to that of the delay compensator 62 employing various filters N designed in the prior art. It can be seen that the configuration has a configuration that can reduce the operation cost compared to the delay compensator 62 of the prior art.

That is, when the delay compensator 2 shown in FIG. 3 is mounted on hardware such as a digital arithmetic device, the operation cost of the hardware applied to the filter 61 of the delay compensator 62 does not deteriorate compared to the prior art without deterioration in control performance. Is a control method suitable for implementation that can reduce

In addition, according to this control method, it is possible to provide a control device by hardware that is less expensive and has low arithmetic performance.

When hardware such as a digital arithmetic device to be mounted has sufficient operation resources, a delay compensator described in Patent Document 1 is described as a delay compensator having equivalent compensation performance to the delay compensator 2 shown in the present embodiment. The FB control system may be implemented as shown in FIG. 6 using a filter 61 designed by technology.

As described above, according to the present embodiment, the processing of the filter 61 of the delay compensator 62 designed in Patent Document 1 is included in the denominator of the filter 61, exp (-τ m · s), and the numerator of the filter 61. Since the calculation of the nominal plant model Pm included in the denominator can be realized by a simple control block configuration common to the calculation processing of the nominal delay element model 15 and the nominal plant model 14 required in the Smith method, According to the present invention, it is possible to provide a feedback control method suitable for implementation that can reduce the operation cost in hardware implementation while maintaining the features and advantages of the delay compensator 62 designed in Patent Document 1, and a motor control apparatus including the same. .

The motor control method and the motor control device according to the present embodiment assume the speed control system 71 in the cascade FB control system of the AC servomotor shown in FIG. 7, and the model of the control object is specifically the following equation (21) It shall be shown to (22) and (23).

Psm is a nominal plant model in the speed control system, Mi is a model idealizing the current control system which is a minor loop control system in the speed control system, and τsm is included in the closed loop of the current control system and the speed control system It is the sum of all delays. Further, J, Ka and Pp are inertia, motor constant and pole-log, respectively, and ωi is a response frequency of the current control system.

Equations (21) to (23) indicate that it is necessary to handle the problem that the controlled object has a pole at the origin in the design of the speed control system in the cascaded FB control system of the AC servomotor.

The velocity FB controller 72 of the velocity control system is a PI controller, and is given by the following equations (24), (25) and (26).

Where L and ωs are the break point ratio and the response frequency of the speed control system, respectively. Generally, in order to regard the current control system as approximately 1, ωi is set to about several to ten times ωs.

If ωs is increased to increase the response of the speed control system, the current control system can not be approximated to 1 unless ωi is simultaneously increased, and it must be regarded as a delay element. In this case, the current control system is a first-order delay element as shown in equation (23), and it is necessary to regard this as a delay element.

In this embodiment, the current control system is regarded as a delay element. In this problem setting, in patent document 1, a delay compensator 82 shown in FIG. 8 is configured, and as a design example of the filter 81, the following equation (27) is cited.

However, as shown in equation (28), Csa is

While having the same structure as the velocity FB controller 86, its control design parameters are determined independently of the velocity FB controller 86.

According to the prior art, the denominator of equation (27) includes the response Mi of the current control system in addition to exp (-τm · s), and the order of the transfer function of the filter of equation (27) tends to be high. is there. Therefore, when the equation (27) is processed by the digital arithmetic unit 713, a high operation cost is required.

The configuration of the speed control system in the cascaded FB control system of the AC servomotor in this embodiment is shown in FIG. In FIG. 9, the delay compensator 92 in the present embodiment has the rotational speed of the AC servomotor to be controlled with respect to the manipulated variable u output from the velocity FB controller 86 and the manipulated variable u output from the velocity FB controller 86. It has a sensor detection value y as an input, and outputs a speed FB signal yb with respect to the target rotational speed r.

The operation of the delay compensator 92 will be described with reference to FIG. The delay compensator 92 rotates the model of the object to be controlled with respect to a signal obtained by the adder / subtractor 94 adding the output of an arbitrary velocity FB controller 93 to the AC servomotor to be controlled and the manipulated variable output by the velocity FB controller 86. The model error signal ye is calculated by subtracting the speed response from the sensor detection value y of the rotational speed of the AC servomotor which is the control object with respect to the operation amount output by the FB controller 86 by the adder / subtractor 89.

In addition, the delay compensator 92 calculates the response of the plant nominal model 84 to the signal obtained by adding the output of an arbitrary velocity FB controller 93 and the manipulated variable output from the velocity FB controller 86 by the adder-subtractor 94 as a predicted FB signal. Then, the signal obtained by processing the model error signal by the filter 91 and the predicted FB signal are added by the adder-subtractor 95, and the result is output as the speed FB signal yb with respect to the target rotational speed r.

The speed FB controller 86 receives a deviation signal obtained by subtracting the speed FB signal yb output from the delay compensator 92 from the target rotational speed r by the adder / subtractor 87, and generates the manipulated variable u for the control target.

In the delay compensator 92 shown in FIG. 9 in the present embodiment, CsA and As (s) are designed, for example, as in the following formulas (29) and (30).

However, Csa in Formula (29) is shown by Formula (28).

The delay compensator 92 designed in this way has an input / output characteristic equivalent to that of the delay compensator 82 including the filter N shown by the equations (27) and (28) designed in Patent Document 1 from the simple calculation. It can be confirmed that That is, the delay compensator 92 designed as in equations (29) and (30) is equivalent to the delay compensator 82 including the filter of equations (27) and (28) designed in Patent Document 1 It has performance.

Equations (29) and (30) both include the transfer characteristic Pm of the nominal plant model 84 that the equation (27) included, and the transfer characteristic Mi · exp (−τm · s) of the nominal delay element model 85. It turns out that the transfer function is simple.

Thus, the reason why the transfer functions of CsA and As (s) are simplified as compared to equation (27) is that Pm and Mi · exp (−τm · s) included in equation (27) This is because the delay compensator 92 is configured as a block configuration that can share the calculation with the calculation of the nominal plant model 84 and the nominal delay element model 85.

As described above, according to this embodiment, the delay compensator 92 in the speed control system of the AC servomotor shown in FIG. 9 is equivalent to the delay compensator 82 adopting various filters N designed in the prior art. The compensation performance can be shown, and the calculation cost can be reduced as compared with the delay compensator 82 of the prior art.

That is, when the delay compensator 92 shown in FIG. 9 is mounted on the digital arithmetic unit 713, the calculation cost of the digital arithmetic unit 713 applied to the filter 81 of the delay compensator 82 is reduced without deterioration of control performance compared It is a control method suitable for implementation that can be reduced.

Further, according to this control method, it is possible to provide a control device by the digital arithmetic device 713 which is cheaper and has low operation performance.

In the speed control system of the AC servomotor, the filter 81 of the delay compensator 82 is expressed by the following equation (31), using the prior art:

In the present embodiment, even in the case where the delay compensator 92 is designed as follows, in the delay compensator 92 shown in FIG.

The delay compensator 82 shown in FIG. 9 and the delay compensator 82 including the filter of the equation (31) have equivalent compensation characteristics.

In this case, for example, as in the following equation (33),

Even when the constant γ is defined, it is possible to suppress the step disturbance applied to the input end of the controlled object without steady-state deviation when the controlled object has a pole at the origin. From the comparison with the equation (30), the delay compensator 92 adopting the equation (28) can be said to be a control method suitable for mounting, if it is the equation (33), without particularly increasing the calculation cost.

1, 61, 81, 91: filter, 2, 42, 52, 62, 82, 92: delay compensator, 3, 16, 93: feedback controller, 4, 5, 6, 18, 35, 37, 39: Adder / subtractor 7, 27: reference model type real feedback control system, 8: model feedback control system, 12: control target, 13: feedback delay element, 14: nominal plant model, 15: nominal delay element model, 71: AC Servo motor speed control system 77: AC servo motor 78: current detector 713: digital arithmetic unit

Claims

A feedback control method including a delay compensator 1 configured of a model to be controlled, an optional filter 1 and an optional feedback controller 1,
The model of the control target includes a nominal plant model that simulates the dynamics of the control target and a nominal delay model that simulates a delay element included in the closed loop of the feedback control system.
The delay compensator 1 uses an operation amount output by a feedback controller 2 that performs feedback control on the control target and an output signal of the control target as input signals.
An output signal of the nominal plant model with respect to a signal obtained by adding the manipulated variable and the output of the arbitrary feedback controller 1 included in the delay compensator 1 by an adder / subtracter is an ideal feedback signal, the manipulated variable and the delayed signal. The signal obtained by subtracting the output signal of the model to be controlled with respect to the signal obtained by adding the output of the optional feedback controller 1 included in the compensator 1 by the adder / subtractor and the output signal of the control target by the adder / subtracter A signal obtained by adding the model error signal processed by the arbitrary filter 1 and the ideal feedback signal by an adder / subtractor while using the model error signal as an input to the arbitrary feedback controller 1 As the output signal,
The feedback controller 2 calculates a deviation between the output signal of the delay compensator 1 and a target value signal with an adder / subtractor, and performs feedback compensation on the control target based on the deviation. Feedback control method.
The feedback control method according to claim 1, wherein
A feedback control method characterized in that the arbitrary filter 1 is an arbitrary real number whose transfer characteristic is greater than zero.
The feedback control method according to claim 1, wherein
A feedback control method characterized in that the transfer characteristic of the arbitrary filter 1 is 1;
A feedback control method including a delay compensator 2 configured of a model to be controlled and a filter 2,
The model of the control target comprises a nominal plant model that simulates the dynamics of the control target and a nominal delay model that simulates a delay element included in the closed loop of the feedback control system.
The delay compensator 2 uses, as input signals, an operation amount output from a feedback controller 2 that performs feedback control on the control target and an output signal of the control target.
A signal obtained by causing the filter 2 to act on an error signal obtained by subtracting an output signal of the control target and an output signal of the model of the control target with respect to the manipulated variable output by the feedback controller 2 by an adder / subtractor And an output signal of the nominal plant model with respect to the manipulated variable output by the feedback controller 2 by using an adder-subtractor as an output signal.
The feedback controller 2 calculates a deviation between the output signal of the delay compensator 2 and a target value signal with an adder / subtractor, and performs compensation on the control target based on the deviation.
The filter 2 is a transfer function of a closed loop system including an arbitrary feedback controller 3 for the control object, a model of the control object, an arbitrary feedback controller 3 for the control object, and a model of the control object. A feedback control method, characterized in that the loop transfer function of the closed loop system is arbitrarily used to be a function configured in the form of a sum difference product quotient.
The feedback control method according to claim 1, wherein
The optional feedback controller 1 has a transfer characteristic equivalent to the optional feedback controller 3 according to claim 4;
The arbitrary filter 1 is given as a transfer function having an appropriate order so that the input / output transfer characteristic of the delay compensator 1 is equivalent to the input / output characteristic of the delay compensator 2 according to claim 4 Feedback control method characterized in that
A motor control apparatus employing a feedback control system including a delay compensator 1 including a model to be controlled, an arbitrary filter 1, and an arbitrary feedback controller 1,
The model of the control target includes a nominal plant model that simulates the dynamics of the control target and a nominal delay model that simulates a delay element included in a closed loop of the feedback control system.
The delay compensator 1 uses as an input signal an operation amount output by a feedback controller 2 that constitutes the feedback control system and performs feedback control on a control target, and an output signal of the control target.
An output signal of the nominal plant model with respect to a signal obtained by adding the manipulated variable and the output of the arbitrary feedback controller 1 included in the delay compensator 1 by an adder / subtracter is an ideal feedback signal, the manipulated variable and the delayed signal. The signal obtained by subtracting the output signal of the model to be controlled with respect to the signal obtained by adding the output of the optional feedback controller 1 included in the compensator 1 by the adder / subtractor and the output signal of the control target by the adder / subtracter A signal obtained by adding the model error signal processed by the arbitrary filter 1 and the ideal feedback signal by an adder / subtractor while using the model error signal as an input to the arbitrary feedback controller 1 As the output signal,
The feedback controller 2 calculates a deviation between the output signal of the delay compensator 1 and a target value signal with an adder / subtractor, and performs feedback compensation on the control target based on the deviation. Motor controller.
The motor control device according to claim 6, wherein
A motor control device characterized in that the arbitrary filter 1 has an arbitrary real number whose transfer characteristic is greater than zero.
The motor control device according to claim 6, wherein
A motor control apparatus characterized in that the transmission characteristic of the arbitrary filter 1 is 1.
A motor control apparatus employing a feedback control system including a delay compensator 2 configured of a model to be controlled and a filter 2 and a feedback controller 2,
The model of the control target includes a nominal plant model that simulates the dynamics of the control target and a nominal delay model that simulates a delay element included in the closed loop of the feedback control system.
The delay compensator 2 takes an operation amount output from the feedback controller 2 and an output signal to be controlled as an input signal.
A signal obtained by causing the filter 2 to act on an error signal obtained by subtracting an output signal of the control target and an output signal of the model of the control target with respect to the manipulated variable output by the feedback controller 2 by an adder / subtractor And an output signal of the nominal plant model with respect to the manipulated variable output by the feedback controller 2 by using an adder-subtractor as an output signal.
The feedback controller 2 calculates a deviation between the output signal of the delay compensator 2 and a target value signal with an adder / subtractor, and performs compensation on the control target based on the deviation.
The filter 2 is a transfer function of a closed loop system including an arbitrary feedback controller 3 for the control object, a model of the control object, an arbitrary feedback controller 3 for the control object, and a model of the control object. A motor control apparatus characterized in that the open loop transfer function of the closed loop system is a function formed arbitrarily in the form of a sum difference product quotient.
The motor control device according to claim 6, wherein
The optional feedback controller 1 has a transfer characteristic equivalent to the optional feedback controller 3 according to claim 9;
The arbitrary filter 1 is given as a transfer function having an appropriate order so that the input / output transfer characteristic of the delay compensator 1 is equivalent to the input / output characteristic of the delay compensator 2 according to claim 9 A motor control device characterized in that.