JPH11184503A - Device and method for control - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit stable control even when a controlled system and/or the actuator of that controlled system has spring characteristics. SOLUTION: In addition to a feed forward(FF) control operating part 1.2 and a feedback(FB) control operating part 16, a resonance cancel filter element 19 is provided for performing operation to cancel the spring characteristics. The resonance cancel filter element 19 has a secondary advance element for providing a minimal amplitude value or secondary delay element for providing a maximal amplitude value and cancels resonance characteristics caused by a spring element provided in a driving system. Besides, a setting part 40 is provided for setting a parameter for resonance cancel filter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method and apparatus for performing servo control of equipment having a drive system requiring high-speed positioning control, such as an industrial robot and a component mounting machine for an electric circuit board.

[0002]

2. Description of the Related Art There are various control objects. For example, even in an industrial robot, a basic control object is an electric motor (motor). There are various types of motors, and, for example, servo motors used in industrial robots will be exemplified below.

Various methods have been proposed for controlling a servomotor. The most basic method is to control the proportional (P) operation, the integral (I) operation and the differential (D) operation in combination. This is the control method.

FIG. 1 is a block diagram of a conventional control device using such a control method. The control device illustrated in FIG. 1 drives a motor 1 as a control object via a motor driving unit (driver) 2.
And a rotary encoder 200 for detecting the rotational position of the rotor of the motor 1.

[0005] A controller (controller) 100 includes a feedforward (FF) control operation unit 12 for performing feedforward control (positive feedback control, FF control) from the target position signal P _ref (or the target angle signal A _ref ). 1 feedback circuit (FB) control operation unit 1 for performing feedback control (negative feedback control, FB control) operation
6 and the control operation unit 1 having the second addition circuit 18
0, a digital / analog conversion circuit (D / A converter) 20, and a sampler 30 that samples a detection signal of the rotary encoder 200 and applies the detection signal to the addition circuit 14.
Having. The controller 100 is a discrete controller that performs sampling and control at a predetermined sampling period, and controls the feed-forward control by the FF control operation unit 12 in the control operation unit 10 and the feed-forward control in the addition circuit 14. Calculated position deviation = (target position signal _Pref
This is a combination of feedback control by the FB control calculation unit 16 based on the position detection signal of the encoder 200).

The FF control calculation unit 12 performs a control calculation defined by the following equation (1).

[Equation 14] …… (1)

The FB control calculation section 16 performs a control calculation defined by the following equation (2).

(Equation 15) …… (2)

In equations 1 and 2, the control parameter k _p is a proportional constant (proportional gain or proportional gain), the control parameter k _d is the differential constant (differential gain), and the control parameter k _i
Indicates an integration constant (integral gain). The control parameter α indicates a feed forward gain (gain), and the control parameter β indicates a speed feed forward gain. Symbol T
Indicates a sampling period, and a variable z ^-1 indicates a first-order lag element. Therefore, in this example, the FF control operation unit 12 performs a combination operation of the proportional (P) control operation and the differential (D) control operation. The FB control calculation unit 16 performs a PID control operation.

The general operation of the control device illustrated in FIG. 1 will be described. The FF control calculation unit 12 performs proportional and differential (PD) with respect to the target position signal P _ref (or the target angle signal A _ref ).
Perform control calculation. The adder circuit 14 outputs the target position signal P
_The deviation is calculated by subtracting the actual position detection signal (or angle detection signal) detected by the encoder 200 with respect to _ref (or the target position signal P _ref ). The FB control calculation unit 16 performs a PID calculation on the deviation. The addition circuit 18
The calculation result of the FF control calculation unit 12 and the calculation result of the FB control calculation unit 16 are added. The above operations are performed digitally (discretely). The calculation result is converted into an analog signal in the D / A converter 20 and the drive of the motor 1 is controlled via the motor drive unit (driver) 2. The result is detected by the encoder 200 and applied to the addition circuit 14 via the sampler 30. This control operation is repeatedly performed at a predetermined sampling cycle.

[0010]

In the servo control device shown in FIG. 1, control parameters for improving control performance,
For example, the control is performed only by the proportional constant k _P , the differential constant k _d , the integral constants k _i , α, and β. However, in an actual drive system, the spring characteristics of the drive units such as the motor driver 2 and the motor 1 are used. Often have resonance characteristics. If control is performed ignoring this resonance characteristic, the stability of the control system may be impaired by the resonance characteristic. The spring characteristics will be described later with reference to FIG.

In general, when a control parameter having high control performance (a control parameter having high sensitivity used for performing precise control) is used, the stability of the control system is reduced, and the stability of the control system is impaired due to the resonance characteristics. Tend to be Conversely, in order to maintain the stability of the control system, the drive system must be controlled with a control parameter with low sensitivity (a control parameter with reduced control performance). Then, sufficient control is not performed. As described above, there is an inherent problem in control that depends on the sensitivity of the control parameter.

An object of the present invention is to overcome the above-described control-related problems. An object of the present invention is to apply a resonance canceling filter for canceling a spring element even if it exists in a mechanical system to be controlled. An object of the present invention is to provide a control device and a control method that enable stable and precise control.

It is another object of the present invention to provide a method and an apparatus for adjusting the parameters of the resonance canceling filter which can easily and appropriately adjust the parameters of the resonance canceling filter.

[0014]

In order to achieve the above-mentioned object, according to the present invention, a secondary advance element and / or a secondary advance element are provided in order to cancel a resonance characteristic caused by a spring element included in a drive system.
Alternatively, the control signal is filtered by a resonance cancellation filter including a second-order lag element.

That is, according to the present invention, in a control device for controlling a control system having a spring characteristic in a controlled object and / or an actuator of the controlled object by a discrete time method, a target command signal and a position or an angle of the controlled object are controlled. A deviation calculation unit for obtaining a difference from the detection signal, a feedback control operation unit for performing a feedback control operation in accordance with the deviation calculated by the deviation calculation unit, and a resonance cancellation for performing an operation for canceling the front spring characteristic with respect to the result A control device having a filter element is provided.

[0016] The resonant cancellation filter element secondary lead element results in amplitude _{minima: (s-z r + z} i j) (s-z
_r -z _i j), or, second-order lag element providing amplitude maximum _{value: 1 / (s-p r} + p i j) (s-p r -p
_i j) or both.

Preferably, the filter characteristic of the resonance canceling filter element is a zero point of the resonance canceling filter element: z _fp ±
z _fi j and the resonance pole of the controlled object and / or the actuator: p _r ± p _i j are matched, and the pole of the resonance canceling filter element: p _fr ± p _fi j and the resonance of the controlled object and / or the actuator Zero: obtained by matching z _r ± z _i j.

The control device of the present invention further includes a resonance canceling filter parameter setting section for setting parameters of the resonance canceling filter element. The resonance canceling filter parameter setting unit includes an amplitude maximum frequency f _fp and a maximum value damping coefficient d _{fp of} the resonance cancellation filter element,
_{Alternatively, a} minimum amplitude frequency f _fz and a minimum value damping coefficient d _fz of the resonance canceling filter are designated, and parameters in the resonance canceling filter element are set in the resonance canceling filter element.

Preferably, the parameter setting section for the resonance cancellation filter applies the following equation from the amplitude minimum frequency f _fz and the minimum value damping coefficient d _fz to determine the zero point z _fr ± z _fi j of the resonance cancellation filter element. Then, the amplitude minimum frequency and the amplitude minimum value sharpness of the resonance canceling filter element are designated independently.

[0020]

(Equation 16)

Preferably, the resonance canceling filter parameter setting unit applies the following equation from the amplitude maximum frequency f _fp and the maximum value damping coefficient d _fp to the pole p _fr ± p _fi j of the resonance canceling filter element. And the sharpness of the amplitude maximum frequency and the amplitude maximum value of the resonance canceling filter element are designated independently.

[Equation 17]

Further, according to the present invention, when a control target and / or a control system having a spring characteristic for an actuator to be controlled is controlled by a discrete time method, a control method for performing a resonance cancellation filter process for canceling the spring characteristic. Is provided.

Further, according to the present invention, the object to be controlled and / or
Or, when controlling a control system having a spring characteristic in the actuator to be controlled by a discrete time method, parameter setting of the resonance cancellation filter element in a control method of performing a resonance cancellation filter process defined by the following equation to cancel the spring characteristic. The method

(Equation 18) The amplitude maximum frequency f _fp , the maximum value damping coefficient d _fp , the amplitude minimum frequency f _fz , and the minimum value damping coefficient d _fz of the resonance canceling filter element are input, and the following equation is calculated to calculate the pole p _{fr of the} resonance canceling filter element. ± p _fi j and zero point z _fr ±
Calculate z _fi j,

[Equation 19]

(Equation 20) Calculate the following equation to calculate the zero point Z of the resonance canceling filter element.
_{Find fr} ± Z _fi j and P _fr ± P _fi j,

(Equation 21)

(Equation 22) Calculate parameters a, b, c, and d by performing the following equation,

(Equation 23)

(Equation 24)

(Equation 25)

(Equation 26) A parameter setting method for a resonance canceling filter for setting the calculated parameters a, b, c, and d in the resonance canceling filter element is provided.

According to the present invention, when a control target and / or a control system having a spring characteristic is controlled by a discrete-time method for a control target and / or an actuator of the control target, a resonance canceling filter process defined by the following formula for canceling the spring characteristic is performed. A method of adjusting the parameters of the resonance cancellation filter element in the control method of performing the above, wherein the zero point of the resonance cancellation filter element is determined so as to cancel the drive system resonance pole, the resonance cancellation filter of the resonance cancellation filter so as not to impair the stability of the control system. A method is provided for adjusting parameters for a resonant cancellation filter that determines a pole.

[0025]

[Equation 27]

Further, according to the present invention, when a control system having a spring characteristic is controlled by a discrete time method on a controlled object and / or an actuator of the controlled object, a resonance canceling filter defined by the following formula cancels the spring characteristic. An adjustment method for a control system that performs processing,

[Equation 28] The amplitude frequency characteristics of the drive system are measured, and the amplitude maximum frequency fp,
The amplitude minimum frequency fz is read, and the maximum value damping coefficient dp and the minimum value damping coefficient _dfz are set to appropriate values. As initial values, the amplitude minimum frequency _ffz = fp of the resonance canceling filter element and the amplitude maximum frequency _fp = Fz, the minimum value damping coefficient d _fz = dp, the maximum value damping coefficient d _fp = dz, and the initial setting value is set as the initial value of the resonance canceling filter element, and is input to the resonance canceling filter parameter setting section. The drive system frequency characteristics including the resonance canceling filter element are measured to confirm whether the amplitude maximum value of the drive system is sufficiently canceled.If the amplitude maximum value of the drive system is not sufficiently canceled, the resonance canceling filter element Either the amplitude minimum frequency f _fz or the minimum value damping coefficient d _fz is changed and input again to the resonance canceling filter parameter setting unit, and The above processing is repeated until the amplitude minimum frequency f _fz and the minimum value damping coefficient d _{fz at} which the width maximum value becomes the smallest are obtained. If the amplitude maximum value of the drive system is sufficiently canceled, the resonance canceling filter at that time is used. The element's amplitude minimum frequency f _fz and minimum value damping coefficient d
_fz is stored, the resonance cancellation filter element is configured using the parameters determined as described above, and the control system including the resonance cancellation filter element is operated, and the operation result of the control system has no problem in stability. An adjustment method of the control system for confirming the above is provided.

Looking at the amplitude frequency characteristics of the drive system including the spring element, the maximum amplitude value and the minimum amplitude value due to the resonance characteristics are observed. Due to the influence of the maximum value of the amplitude, the amplitude in the high frequency region is increased over a wide frequency range. For this reason, the open-loop transfer function of the entire control system including the control target and the control device including the drive system was observed. Occasionally, the gain margin is reduced and oscillation becomes easy. On the other hand, in the frequency characteristic of the resonance cancellation filter, there are a minimum amplitude value due to the zero point and a maximum amplitude value due to the pole of the resonance cancellation filter. By setting the parameters of the resonance canceling filter such that the minimum value of the amplitude due to the zero point has exactly the opposite characteristic to the maximum value of the amplitude of the resonance pole due to the resonance characteristics of the drive system, the frequency characteristics of the drive unit including the filter are as if they were. The frequency characteristic is as if there is no amplitude maximum value due to the resonance pole. As a result, the stability of the control system can be as stable as the absence of the resonance pole of the drive unit. However, at this time, an amplitude maximum occurs at another frequency due to a pole in the resonance canceling filter. It is necessary to arrange at an appropriate position so that the maximum value of the amplitude does not impair the stability of the control system. The parameters of the resonance canceling filter giving the above characteristics are automatically calculated and set by the parameter setting unit by specifying the maximum amplitude frequency and the minimum amplitude frequency of the drive unit and the respective damping coefficients.

When the operation of the drive system is controlled by the control device including the resonance cancellation filter, the resonance cancellation filter operates so as to cancel the influence of the resonance pole of the drive system, and the control system is not affected by the influence of the drive system resonance pole. Prevent stability and achieve good control.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A control device according to an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 2 is a configuration diagram of a servo control device which controls a servo motor as an embodiment of the control device according to the present invention.

The configuration of the servo control device illustrated in FIG. 2 is similar to that of the servo control device illustrated in FIG. 1, but the control operation unit 10A of the controller (controller) 100A illustrated in FIG. An element 19 is added, and a resonance canceling filter parameter setting unit 40 for setting parameters of the resonance canceling filter element 19 is added to the controller 100A.

That is, the servo control device illustrated in FIG. 2 includes a controller 100A for driving a motor 1 as a control object via a motor drive unit (driver) 2 and a rotary for detecting the rotational position of the rotor of the motor 1. Encoder 200
And

The controller 100A receives the target position signal P
_ref (or the target angle signal A _ref ), a feedforward (FF) control calculation unit 12 that performs feedforward control (positive feedback control, FF control) calculation, a first addition circuit 1
4. a feedback (FB) control operation unit 16 for performing feedback control (negative feedback control, FB control) operation, a control operation unit 10A having a second addition circuit 18 and a resonance cancellation filter element 19, and a digital / analog conversion circuit ( A D / A converter 20, a sampler 30 that samples a detection signal of the encoder 200 and applies the sampled signal to the addition circuit 14, and a resonance canceling filter parameter setting unit 40. The controller 100A is also a discrete controller that controls the sampler 30 by performing sampling at a predetermined sampling cycle, and the control content is the FF control operation unit 1
2 and the feedback control in the FB control calculation unit 16 based on the position deviation calculated by the addition circuit 14 = (target position signal P _ref (or target angle signal A _ref ) _-position detection signal of encoder 200). It is a combination.

The FF control operation unit 12 performs a feedforward control operation in accordance with the control algorithm shown in Expression 1. The FB control calculation unit 16 performs a feedback control calculation according to the control algorithm shown in Expression 2. In this example, the FF control operation unit 12 performs a combination operation of a proportional (P) control operation and a differential (D) control operation, and the FB control operation unit 16 performs a PID control operation.

The resonance canceling filter element 19 performs an operation represented by the following equation (3).

(Equation 29) …… (3)

The characteristics of the resonance canceling filter element 19 usually include at least a second-order lag element, but may include a second-order advance element depending on the control target. In this embodiment, a case where both a second-order delay element and a second-order advance element are included will be described as a representative example.

The operation of the servo control device illustrated in FIG. 2 will be described. The FF control calculation unit 12 performs a proportional and differential (PD) control calculation on the target position signal P _ref (or the target angle signal A _ref ) based on Equation 1. The adder circuit 14 subtracts the actual position detection signal (or angle position detection signal) detected by the encoder 200 from the target position signal P _ref (or target angle signal A _ref ) to calculate a deviation. The FB control calculation unit 16 calculates PID of the deviation based on Equation 2.
Perform the operation. The addition circuit 18 adds the operation result of the FF control operation unit 12 and the operation result of the FB control operation unit 16. The resonance canceling filter element 19 performs an operation based on Equation 3.
The above operation is performed digitally. The calculation result is converted into an analog signal in the D / A converter 20, and the driving of the motor 1 is controlled via the motor driving unit 2. The motor driver 2 controls the rotation operation of the motor by adjusting the power supplied to the motor 1 according to the drive signal from the D / A converter 20. The rotation operation result of the motor 1 is detected by the encoder 200 and applied to the addition circuit 14 via the sampler 30 at a predetermined sampling cycle. This control operation is repeated at a predetermined sampling cycle.

Hereinafter, the resonance canceling filter element 19 and the parameter setting section 40 for the resonance canceling filter will be described.

[0039] As the resonance cancellation filter element 19 resonating cancellation filter element 19, shown in Formula 3, 2
The following delay element, made from the secondary lead element and the gain k _f,
By performing the calculation defined by Expression 3, the resonance pole of the drive system is canceled, and the stability of the control system is improved. The resonance pole of the drive system is described in detail in JP-A-8-171402.

The reason why the calculation by the resonance canceling filter element 19 improves the stability of the control system will be described. Drive system with spring element (motor 1 and motor driver 2)
Is generalized into inertia 1 and inertia 2 as illustrated in FIG.
And represented as a two inertial system with Two inertia 1, 2
Are connected via a spring element. Inertia 1 and 2 have viscosity 1 and 2, respectively. The transfer function G (s) of the inertial system illustrated in FIG. 3 can be generally expressed by the following equation (4).

[Equation 30] (4) where J ₁ is the inertia constant of inertia 1 (inertia constant), J ₂ is the inertia constant of inertia 2 (inertia constant), K is the spring constant of the spring element, and D ₁ is a viscous friction coefficient of inertia 1, D ₂ is the viscous friction coefficient of inertia 2, s is a Laplace operator.

FIG. 4A shows the frequency characteristics of the two inertial system.
It is shown in (B). FIG. 4A is a graph showing amplitude characteristics, and FIG. 4B is a graph showing phase characteristics. FIG.
(A) and (B) respectively show characteristic curves A1 and P1 when there is a spring element and characteristic curves A when there is no spring element.
It is a figure which shows 0, P0. The case where there is no spring element is a case where it is assumed that they are connected by an ideal rigid body instead of the spring element. Considering the amplitude characteristic illustrated in FIG. 4A, when the spring element is present, the amplitude maximum value due to the resonance pole of the resonance characteristic and the amplitude minimum value due to the resonance zero are smaller in the resonance characteristic than when the spring element is absent. Can be seen. Under the influence of the maximum value of the amplitude, the amplitude in the high frequency region is increased over a wide frequency range, and the amplitude characteristics are increased. For this reason, when considering the open loop transfer function of the entire control system including the control target including the drive unit and the control device, the gain margin (gain margin) decreases, and the control system becomes unstable.
Oscillation becomes easy.

In order to overcome this problem and perform highly stable operation control of the drive unit, the resonance canceling filter element 19 illustrated in FIG. 2 is used. Hereinafter, the resonance canceling filter element 19
Will be described in detail.

Equation 4 indicating the transfer function G (s) of the driving section can be rewritten as Equation 5.

(Equation 31) …… (5)

Considering Equation 29, one inertial system: 1 / s
In (J's + D '), a secondary advance element: (s- _zr + zi _{)
j) (s-z r -z} i j), 2 -order lag element: 1 / (s-
_{p r + p i j) (} s-p r -p i j), and can be considered as multiplied by the gain K _f. Here, the gain _Kf is a constant gain that makes the amplitude frequency characteristics of Expression 5 and Expression 4 the same. j is an operator representing an imaginary number.

The minimum value of the amplitude shown in FIG.
_{(S-z r + z i} j) (s-z r -z i j) is due to the amplitude maxima secondary delay _{element: 1 / (s-p r} +
is due to the _{p i j) (s-p} r -p i j). Therefore, in the servo controller illustrated in FIG. 2, the second-order leading element that gives the minimum amplitude: (s−z _r + z _i j)
(S−z _r −z _i j) and a second-order lag element that provides an amplitude maximum value: 1 / (s−p _r + p _i j) (s−p _r −p
It is desirable to insert a component that offsets _i j). Equation 6 shows the offset component.

(Equation 32) ...... (6)

The resonance canceling filter element 19 is basically expressed by the following equation (6).
Is calculated. However, the zero point of the resonance cancellation filter element 19: z _fp ± z _fi j and the drive system of the resonance poles match p _r ± p _i j, i.e. the _{z fr ± z fi j = p} r ± p i j, The pole of the resonance canceling filter element 19: p _fr ± p _fi j
A drive system of the resonant zero: z _r to match the ± z _i j, i.e., FIG. 3 by the _{p fr ± p fi j = z} r ± z i j
The resonance pole and resonance zero of the two inertial system illustrated in FIG.
(A) is canceled by the resonance canceling filter element 19 and can be regarded as a pseudo-inertia system: 1 / s (J's + D '). As a result, the amplitude maximum value of the frequency characteristic due to the resonance characteristic of the drive system is canceled, and the frequency characteristic becomes like a one inertial system (curve P0 in FIG. 4A). As a result, a decrease in the gain margin as viewed from the open loop transfer function is also relieved, and control with high stability can be performed. As described above, by providing the resonance canceling filter element 19 having the characteristic shown in Expression 3, the stability of the control system is increased and good control can be realized.

The resonance cancellation filter parameter setting unit 40 then describes resonance cancellation filter parameter setting unit 40. The parameter setting unit 40 for the resonance cancellation filter illustrated in FIG. 2 includes the amplitude maximum frequency f _fp and the maximum value damping coefficient d _fp of the resonance cancellation filter element 19 or the amplitude minimum frequency _ffz and the minimum value damping coefficient d of the resonance cancellation filter. _fz and the resonance canceling filter element 19
Output the parameters a, b, c, and d appearing in Equation 3 in

The damping coefficient will be described. Generally, the frequency characteristic of the resonance canceling filter element 19 is shown in FIG.
It is illustrated as (B). FIG. 5A is a graph showing the amplitude characteristic of the resonance canceling filter element 19, and FIG.
(B) is a graph showing phase characteristics. As shown in FIG. 5 (A), it has one amplitude minimum value and one amplitude maximum value. In the resonance cancellation filter element 19, it is possible to offset the effect of the drive system resonant pole by matching the sharpness of the frequency f _fz and amplitude minima give amplitude minima on the frequency f _p and sharpness of the drive system resonant pole. Further, the influence of the drive system resonance zero is canceled by matching the amplitude maximum frequency f _fp giving the amplitude maximum value of the resonance cancellation filter element 19 and the sharpness of the amplitude maximum to the frequency f _z and the sharpness of the drive system resonance zero. Can be. However, the zero point giving the amplitude minimum value characteristic of the resonance canceling filter element 19: z _fr ±
To find z _fi j, the real part z _fr or the imaginary part z _{fi of the} zero point
Is changed, the sharpness of the amplitude minimum frequency f _fz and the amplitude minimum value simultaneously change, and the resonance canceling filter element 19
Finding the appropriate zero for is laborious. Similarly,
The pole p _fr that gives the maximum value characteristic of the resonance canceling filter element 19
To find ± p _fi j, the real part p _fr or the imaginary part p _{fi of the} pole
Is changed, the amplitude maximum frequency f _fp and the sharpness of the amplitude maximum value simultaneously change, and the resonance canceling filter element 19
Finding the right pole for is time-consuming.

Therefore, in the present embodiment, the minimum value damping coefficient d _fz corresponding to the sharpness of the amplitude minimum value of the resonance canceling filter element 19 is expressed by Equation 7, and the maximum value corresponding to the sharpness of the amplitude maximum value of the resonance canceling filter element 1 is obtained. Value damping coefficient d _fp
Is defined as in Expression 8.

[Equation 33] …… (7)

(Equation 34) …… (8)

The minimum amplitude frequency f _fz (Hz) and the maximum amplitude frequency f _fp (Hz) are given by equations 9 and 10, respectively.

(Equation 35) ...... (9)

[Equation 36] …… (10)

Thus, the zero point: z _fr ± z _fi j of the resonance canceling filter element 19 is obtained from the above-mentioned minimum amplitude frequency f _fz and the minimum value damping coefficient d _fz as Expression 11.

(37) …… (11)

When the minimum value damping coefficient d _fz > 1, the zero point is on the real axis and has no vibration and does not contribute to canceling the resonance. Therefore, the minimum value damping coefficient d _fz is set in the range of 0 <d _fz ≦ 1. FIG. 6 shows how the frequency characteristic of the secondary advance element in the resonance canceling filter element 19 changes when the minimum value damping coefficient d _fz is changed.
(A) and (B) show. FIG. 6A is a graph showing amplitude characteristics, and FIG. 6B is a graph showing phase characteristics. Referring to FIG. 6A, the minimum value damping coefficient d
_{When fz} increases, the amplitude minimum frequency f _fz does not change and the negative peak of the amplitude minimum value becomes gentle. That is, Equation 7
It can be seen that the minimum value damping coefficient d _fz represented by affects only the sharpness of the amplitude minimum value. Similarly, the pole p _fr ± p _fi j of the resonance canceling filter is obtained as Expression 12 from the amplitude maximum frequency f _fp and the maximum value damping coefficient d _fp .

(38) …… (12)

When the maximum damping coefficient d _fp > 1, the pole is on the real axis and has no vibration and does not contribute to canceling the resonance. Therefore, in the present embodiment, the maximum value damping coefficient d _fp is set in the range of 0 <d _fp ≦ 1.

FIGS. 7A and 7B show how the frequency characteristic of the secondary delay element in the resonance canceling filter element 19 changes when the maximum value damping coefficient _dfp is changed. FIG.
7A is a graph showing amplitude characteristics, and FIG. 7B is a graph showing phase characteristics. Referring to FIG. 7A,
When the maximum value damping coefficient _dfp increases, the amplitude maximum frequency _ffp does not change and the peak of the amplitude maximum value becomes gentle. That is, it can be seen that the maximum value damping coefficient d _fp given by Expression 8 affects only the sharpness of the amplitude maximum value.

As described above, in the present embodiment,
Applying Equation 11 from the amplitude minimum frequency f _fz and the minimum value damping coefficient d _fz , the zero point z of the resonance canceling filter element 19 is obtained.
_{By obtaining fr} ± z _fi j, the amplitude minimum frequency and the sharpness of the amplitude minimum value of the resonance canceling filter element 19 can be independently specified. Further, the resonance cancellation filter element 1 is obtained by applying Equation 12 from the amplitude maximum frequency f _fp and the maximum value damping coefficient d _fp.
By _{obtaining the} pole p _fr ± p _fi j at 9, the amplitude maximum frequency and the sharpness of the amplitude maximum value of the resonance canceling filter element 19 can be independently specified. Thereby, the zero point and the pole of the resonance canceling filter element 19 having the frequency characteristic that cancels out the drive system resonance characteristic can be easily obtained.

Next, how to calculate the parameters a, b, c and d used in the resonance canceling filter element 19 will be described.

It is assumed that the poles p _fr ± p _fi j and the zero point z _fr ± z _fi j of the resonance canceling filter element 19 are given by Expressions 11 and 12. Here, since the resonance canceling filter element 19 performing the calculation shown in Expression 6 is realized by the control calculation unit 10A performing the discrete calculation, the resonance canceling filter element 19 is realized by the discrete calculation.

First, the resonance canceling filter element 1 shown in Equation 6
9 poles: equivalent to p _fr ± p _fi j, poles p _fr ± in the z plane
p _fi j is calculated by applying Equation 13.

[Equation 39] ...... (13)

Further, the zero point Z on the z-plane corresponding to the zero point z _fr ± z _fi j of the resonance canceling filter element 19 shown in the equation (6).
_fr ± Z _fi j is calculated by applying Equation 14.

(Equation 40) …… (14)

The characteristics of the discrete resonance canceling filter element 19 having poles and zeros on the z-plane calculated by applying Expressions 13 and 14 are expressed by Expression 15.

[Equation 41] ...... (15)

From the equation (15), the control operation unit 10 illustrated in FIG.
The parameters a, b, c, and d of A are defined by Expressions 16 to 19.

(Equation 42) ...... (16)

[Equation 43] ...... (17)

[Equation 44] ...... (18)

[Equation 45] ...... (19)

The discrete-time resonance canceling filter element 19
Is realized by a sequence expression represented by Expression 20.

[Equation 46] (20) where in _k is an input value to the filter at time k, and out _k is an output value of the filter at time k.

Here, 1 / K ′ _f is a coefficient that makes the DC amplitude of the discrete-time resonance canceling filter element 19 in Equation 15 be 1, and is defined by Equation 21.

[Equation 47] …… (21)

Parameter setting section 40 for resonance canceling filter
Calculates the parameters a, b, c, and d in the control calculation unit 10A by performing the above-described calculation, and sets the parameters in the resonance canceling filter element 19.

FIG. 8 is a flowchart showing the operation of the resonance canceling filter parameter setting section 40. Less than,
The operation of the resonance canceling filter parameter setting unit 40 is shown in FIG.
Will be described with reference to FIG.

Step 1 (S1): In the resonance canceling filter parameter setting unit 40, the amplitude maximum frequency f _fp , the maximum value damping coefficient d _fp , the amplitude minimum frequency f _fz , and the minimum value damping coefficient d _fz of the resonance cancellation filter element 19 are set. Enter z.

Step 2 (S 2): The resonance canceling filter parameter setting unit 40 performs the operations of the equations 11 and 12 to obtain the poles p _fr ± p _fi j and the zero point z _fr ± z _fi j of the resonance canceling filter element 19. Is calculated.

Step 3 (S3): For resonance canceling filter
The parameter setting unit 40 performs the calculations of Expressions 13 and 14.
U. Thereby, the zero point Z of the resonance canceling filter element 19 is obtained._fr
± Z _fij and P_fr± P_fij is determined.

Step 4 (S4): The resonance canceling filter parameter setting unit 40 calculates the parameters a, b, c, and d by performing the calculations of the equations 16 to 19, and calculates the calculated parameters a, b, c, and d. The resonance canceling filter element 19 is set.

As described above, the parameters a, b, c, and d of the resonance canceling filter element 19 can be calculated, and are set and used in the resonance canceling filter element 19.

Next, a method of adjusting the parameters of the resonance canceling filter element 19 will be described. In the control using the resonance canceling filter element 19 illustrated in FIG. 2, in order to prevent the gain margin of the control system from decreasing due to the influence of the maximum amplitude due to the drive system resonance characteristic, the zero point of the resonance canceling filter element 19 is set to the drive system resonance. The poles need to be well offset. Since the pole of the resonance canceling filter element 19 is a pole newly added by the control system, it is necessary to set the parameters of the resonance canceling filter element 19 so as not to impair the stability of the control system. Therefore, as a procedure for adjusting the parameters of the resonance canceling filter element 19, (1) first, the zero point of the resonance canceling filter element 19 is determined so as to cancel the drive system resonance pole, and (2) the stability of the control system is impaired. The poles of the resonance canceling filter are determined so as not to cause the problem. Since the control system can be controlled stably, the pole of the resonance canceling filter element 19 does not always need to cancel the drive system zero point. In other words, the first is that the stability is not impaired even if the zero point of the drive system is not canceled. Therefore, the maximum value damping coefficient d _fp and the maximum amplitude frequency f _fp of the resonance canceling filter element 19 are changed while confirming the stability of the control system.

FIG. 9 is a flowchart showing the operation of adjusting the parameters of the resonance canceling filter element 19.

Step 11: First, the amplitude frequency characteristics of the drive system are measured, and the amplitude maximum frequency f _p and the amplitude minimum frequency f _z are measured.
Read. Further, the maximum value damping coefficient d _p and the minimum value damping coefficient d _fz are set to appropriate values.

Step 12: Next, as an initial value setting,
The amplitude minimum frequency f _fz of the resonance canceling filter element 19 =
f _p , the amplitude maximum frequency f _fp = f _z , the minimum value damping coefficient d _fz = d _p , and the maximum value damping coefficient d _fz = d _z .

Step 13: The initial set value is set as the initial value of the resonance canceling filter element 19 and input to the resonance canceling filter parameter setting section 40.

Steps 14 and 15: The frequency characteristics of the drive system including the resonance canceling filter element 19 are measured, and it is confirmed whether or not the maximum amplitude of the drive system is sufficiently canceled.

Step 16: If the amplitude maximum value of the drive system is not sufficiently canceled, either the amplitude minimum frequency _ffz or the minimum value damping coefficient _dfz of the resonance canceling filter is changed, and the process returns to step 13. Are input to the parameter setting unit again.

Steps 13 to 15 and 16 are repeated until the amplitude minimum frequency f _{fz at} which the amplitude maximum value becomes the smallest and the minimum value damping coefficient d _fz are obtained.

Step 17: If the maximum amplitude of the driving system is sufficiently canceled, the resonance canceling filter element 19 at that time is used.
Minimum frequency f _fz and minimum value damping coefficient d _fz
Is stored.

Step 18: A resonance canceling filter element 19 is constructed using the parameters determined as described above,
The servo control device illustrated in FIG. 2 including the resonance canceling filter element 19 is operated.

Step 19: Check whether the operation result of the servo control device has no problem in stability.

Step 20: If there is a problem with the stability, the resonance canceling filter parameter setting unit 40 first increases the local maximum damping coefficient d _fz and inputs it to the resonance canceling filter parameter setting unit 40. The process is terminated when the maximum value damping coefficient _dfp is increased and there is no problem in stability.

Steps 21 to 24: If there is a problem in stability even when the maximum value damping coefficient _dfp is increased to 1, the resonance canceling filter parameter setting unit 40 sets the maximum value damping coefficient _dfp = 1. The maximum amplitude frequency f _fp is increased until there is no problem in the stability, and is input to the resonance canceling filter parameter setting unit 40.

Step 25: The characteristics of the resonance canceling filter are determined as described above.

As described above, as an embodiment of the present invention, a motor has been exemplified as a control object, and a servo control device having a resonance canceling filter has been described. However, the present invention is not limited to the above-described embodiment, and various control devices can be used. Applicable to For example,
The control object is not limited to the motor described above, and can be applied to various control objects exhibiting spring characteristics and their actuators. Although the two-inertia system is typically illustrated as the spring characteristic, the present invention can be applied to a controlled object and an actuator having other spring characteristics. In that case, the characteristics of the resonance cancellation filter element 19 are different from those described above.

In the above embodiment, an example has been described in which the resonance canceling filter element 19 has the filter characteristics represented by the equations (6) and (15).
The present invention can be applied to a case where only the secondary delay element or only the secondary advance element is used.

In the controller 100A illustrated in FIG.
The FF control operation unit 12 is not essential. Therefore, the present invention can be applied to a control device in which the FF control operation unit 12 does not exist. The arithmetic expression of the FF control arithmetic unit 12 and the arithmetic expression of the FB control arithmetic unit 16 described with reference to Expressions 1 and 2 are examples, and are expressed by an algorithm according to the control target.

[0088]

According to the control device of the present invention, by applying a resonance canceling filter element for canceling the spring characteristics of the controlled object and / or the actuator (drive unit),
The stability of the control system can be increased by canceling the influence of the resonance pole of the resonance characteristics due to the spring element of the drive unit, and as a result, good operation control can be realized.

According to the present invention, the parameter of the resonance canceling filter element can be easily obtained by calculating the value of the parameter from the resonance frequency and the margin coefficient.
The parameter adjustment time of the resonance canceling filter element can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a conventional servo control device that controls a motor.

FIG. 2 is a configuration diagram of a servo control device that controls a motor as a first embodiment of the control device according to the present invention.

FIG. 3 is a diagram illustrating a drive system having a spring element as a two-mass system.

4 (A) and 4 (B) are graphs showing frequency characteristics of the two inertial system illustrated in FIG. 3, and FIG. 4 (A) is a graph showing amplitude characteristics, and FIG. 4 (B) Is a graph showing phase characteristics.

FIGS. 5A and 5B are graphs showing frequency characteristics of the resonance canceling filter element illustrated in FIG. 2;
FIG. 5A is a graph showing amplitude characteristics, and FIG. 5B is a graph showing phase characteristics.

FIGS. 6A and 6B show how the frequency characteristic of the second-order lead element in the resonance canceling filter element changes when the minimum value damping coefficient d _fz is changed in the present embodiment. FIG. 6A is a graph showing amplitude characteristics, and FIG. 6B is a graph showing phase characteristics.

FIGS. 7A and 7B show how the frequency characteristic of the second-order lag element in the resonance canceling filter element changes when the maximum value damping coefficient d _fp is changed in the present embodiment. FIG. 7A is a graph showing an amplitude characteristic, and FIG. 7B is a graph showing a phase characteristic.

FIG. 8 is a flowchart showing a calculation operation of a resonance canceling filter parameter setting unit illustrated in FIG. 2;

FIG. 9 is a flowchart illustrating an operation of adjusting a parameter of a resonance canceling filter element.

[Explanation of symbols]

1, motor 2, motor driver 100A, controller (controller) 200, rotary encoder 10A, control operation unit 12, feedforward (FF) control operation unit 14, addition circuit 16, feedback ( FB) Control calculation unit 18 Addition circuit 19 Resonance cancellation filter element 20 D / A converter 30 Sampler 40 Parameter setting unit for resonance cancellation filter

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁶ Identification code FI G05D 3/12 305 G05D 3/12 305V

Claims (15)

[Claims] 1. A control device for controlling a control system having a spring characteristic for a control target and / or an actuator of the control target by a discrete time method, wherein a difference between a target command signal and a position or angle detection signal of the control target is determined. A control comprising: a deviation calculation unit to be obtained; a feedback control calculation unit for performing a feedback control calculation in accordance with the deviation calculated by the deviation calculation unit; and a resonance cancellation filter element for performing a calculation for canceling the spring characteristic with respect to the result. apparatus. Wherein said resonant cancellation filter element secondary lead element results in amplitude _{minima: (s-z r + z} i j) (s-z
having _r -z _i j), the control device according to claim 1. Wherein the resonant cancellation filter element secondary delay element to bring the amplitude _{maxima: 1 / (s-p r} + p i j) (s
-P _r -p _i j) having a control device according to claim 1. Wherein said resonant cancellation filter element secondary lead element results in amplitude _{minima: (s-z r + z} i j) (s-z
_r -z _i j) and the amplitude maxima second-order lag element results _{in: 1 / (s-p r} + p i j) (s-p r -p i j) having a control device according to claim 1. 5. The filter characteristic of the resonance canceling filter element includes a zero point of the resonance canceling filter element: z _fp ± z _fi j,
The resonance pole of the control target and / or the actuator:
A method wherein the values of p _r ± p _i j are matched, and the pole of the resonance canceling filter element: p _fr ± p _fi j is matched with the resonance zero of the controlled object and / or the actuator: z _r ± z _i j. 5. The control device according to 4. 6. The control device according to claim 4, further comprising a resonance canceling filter parameter setting unit for setting parameters of the resonance canceling filter element. 7. The resonance canceling filter parameter setting section includes an amplitude maximum frequency f _fp and a maximum value damping coefficient d _{fp of} the resonance cancellation filter element, or an amplitude minimum frequency _ffz and a minimum value damping coefficient of the resonance cancellation filter. The control device according to claim 6, wherein d _fz is specified, and a parameter in the resonance cancellation filter element is set in the resonance cancellation filter element. 8. The resonance canceling filter parameter setting section comprises: a minimum amplitude frequency f _fz and a minimum value damping coefficient d.
7. The method according to claim 6, wherein the following equation is applied from _fz to obtain a zero point z _fr ± z _fi j of the resonance canceling filter element and independently designate the amplitude minimum frequency and the sharpness of the amplitude minimum value of the resonance canceling filter element. Control device. (Equation 1) 9. The parameter setting section for a resonance canceling filter includes a maximum amplitude frequency f _fp and a maximum value damping coefficient d.
_Calculate the pole p _fr ± p _fi j of the resonance canceling filter element by applying the following equation from _fp, and independently designate the amplitude maximum frequency and the sharpness of the amplitude maximum value of the resonance cancellation filter element,
The control device according to claim 6. (Equation 2) 10. A feedforward control operation unit for performing a feedforward control operation in response to a target command signal,
2. The control according to claim 1, further comprising an adding unit that adds an operation result of the feedforward control operation unit and an operation result of the feedback control operation unit, wherein the resonance canceling filter element performs the filtering on the addition result. 3. apparatus. 11. A control method for performing a resonance canceling filter process for canceling a spring characteristic when a control system having a spring characteristic is controlled by a discrete time method for a controlled object and / or an actuator of the controlled object. 12. A control method for performing a resonance canceling filter process defined by the following equation for canceling the spring characteristic when controlling a control system having a spring characteristic for a controlled object and / or an actuator of the controlled object by a discrete time method. A parameter setting method of the resonance canceling filter element according to The amplitude maximum frequency f _fp , the maximum value damping coefficient d _fp , the amplitude minimum frequency f _fz , and the minimum value damping coefficient d _fz z of the resonance cancellation filter element are input, and the following equation is calculated to calculate the pole p of the resonance cancellation filter element. _fr ± p _fi j and zero z _fr
Calculate ± z _fi j and (Equation 5) The following equation is calculated to calculate the zero point z of the resonance canceling filter element.
_fr ± z _fi j and p _fr ± p _fi j are obtained, and (Equation 7) The parameters a, b, c, and d are calculated by performing the calculation of the following equation, and (Equation 9) (Equation 10) [Equation 11] A method for setting parameters for a resonance cancellation filter, wherein the calculated parameters a, b, c, and d are set in the resonance cancellation filter element. 13. A control method for performing a resonance canceling filter process defined by the following equation to cancel the spring characteristic when controlling a control target and / or a control system having a spring characteristic in an actuator of the control target by a discrete time method. Wherein the parameters of the resonance canceling filter element are adjusted, wherein the zero point of the resonance canceling filter element is determined so as to cancel the drive system resonance pole, and the pole of the resonance canceling filter is determined so as not to impair the stability of the control system. Adjustment method of resonance cancellation filter parameters. (Equation 12) 14. The method according to claim 13, wherein the maximum value damping coefficient d _fp and the maximum amplitude frequency f _fp of the resonance cancellation filter element are changed while confirming the stability of the control system. 15. A control system for performing a resonance canceling filter process defined by the following equation for canceling the spring characteristic when controlling a control system having a spring characteristic for a control target and / or an actuator of the control target by a discrete time method. Is a method of adjusting The amplitude frequency characteristics of the drive system are measured, and the amplitude maximum frequency fp,
The amplitude minimum frequency fz is read, and the maximum value damping coefficient dp and the minimum value damping coefficient _dfz are set to appropriate values. As the initial value setting, the amplitude minimum frequency _ffz = fp of the resonance canceling filter element and the amplitude maximum frequency _ffp = Fz,
The minimum value damping coefficient d _fz = dp, the maximum value damping coefficient d _fp = dz, the initial setting value is set as the initial value of the resonance canceling filter element, and input to the parameter setting unit for the resonance canceling filter, and the resonance canceling filter element is used. The drive system frequency characteristics including the above are measured to check whether the drive system maximum amplitude is sufficiently canceled out. If the drive system maximum amplitude is not sufficiently canceled out, the amplitude minimum frequency f of the resonance canceling filter element is determined. Either _fz or the minimum value damping coefficient d _fz is changed and input to the resonance canceling filter parameter setting section again to obtain the amplitude minimum frequency f _fz and the minimum value damping coefficient d _fz at which the amplitude maximum becomes the smallest. The above processing is repeated until the amplitude maximum value of the drive system is sufficiently canceled, and the amplitude minimum value of the resonance canceling filter element at that time is minimized. The frequency f _fz and the minimum value damping coefficient d _fz are stored, the resonance canceling filter element is configured using the parameters determined as described above, and the control system including the resonance canceling filter element is operated. A control system adjustment method to check whether the operation result has no problem with stability.