JPS6358504A - Gain setting system for digital servo controller - Google Patents

Abstract

PURPOSE:To simplify calculation of both feedback and observer gains by using a gain setting device consisting of a feedback gain table, an observer gain table and a gain setting part. CONSTITUTION:A feedback gain table 131 of a gain setting device 13 contains at least a pair of feedback gains K0 of an optimum regulator 11 which are obtained with a sampling cycle TS0 of a digital servo controller 10 and the gain GS0 of a controlled system 15 respectively. Then an observer gain table 132 stores at least a pair of observer gains F0 of an observer 12 with said cycle TS0 and gain GS0. Thus the feedback gain K1 and the observer gain F1 of the regulator 11 can be simply calculated based on the gains K0 and F0 of a feed back gain table 131 and gain setting part 133 and set to the regulator 11 and the observer 12 with a sampling cycle TS1 of the controller 10 and the gain GS1 of the controlled system 15 respectively.

Description

[Detailed Description of the Invention] [Summary] In a gain setting method for a digital servo control device equipped with an optimal regulator and an observer, the control target is a target whose transfer function is “G/S”. The feedback gain and observer gain of the optimal regulator for the gain are determined in advance and stored in a table, and the feedback gain and observer gain for other sampling periods and the gain of the controlled object are calculated based on each gain in the table. This simplifies calculation of the feedback gain and observer gain, and allows desired response characteristics to be quickly achieved.

[Industrial application field]

The present invention provides a method for setting the feedback gain and other gains of a digital servo control device, and in particular, a method for setting the feedback gain and other gains of a digital servo control device. This invention relates to a gain setting method for a digital servo control device that is equipped with an optimal regulator that works to make the difference between the control amount and the control amount zero, and an observer that estimates the internal state of a controlled object.

[Conventional technology]

2. Description of the Related Art Numerical control (NC) devices, industrial robots, and the like use DC motors to move the workpieces and joints that constitute them. That is, position (rotation angle) control or speed control is performed on the DC motor to cause the workpiece or each joint to reach a predetermined target position or speed.

In that case, in order for the DC motor to reach the target position or speed quickly and stably, a servo system is used that feeds back the output of the DC motor to be controlled so that it reaches the desired target value. However, gravity, friction,
In order to configure a servo system that is stable and has good coordination without being affected by other disturbances, it is necessary to appropriately set the feedback gain and other gains of the servo system.

In the past, gain setting methods for servo systems had no clear guidelines and relied on experience and intuition, but recently, gain setting methods for control systems based on so-called modern control theory, especially control system gains based on optimal regulator theory, have been introduced. The setting method has been attracting attention. An outline of the gain setting method based on this optimal regulator theory will be explained below.

When the controlled object is expressed by a state equation, it is expressed by the following equations (1) and (2).

Xft) = [A C] Xft) + Be
u(t) ... Old "(1))'(
t)=CTXftl...Old...
...(2) Here, u (t): input of the controlled object, y (t): output of the controlled object, X(t): internal state vector of the controlled object, which is generally a linear vector. .

[AC3: nxn matrix, Bc: linear vector, Can
is the next vector. Further, "." is a differential symbol, and "T" is a transposition symbol. In addition, in the formula symbol, [ ] indicates a matrix, an uppercase letter indicates a vector, and a lowercase letter indicates a scalar quantity. Further, the scalar quantity of an uppercase letter is indicated by adding a lowercase letter "S" to the uppercase letter.

Equations (1) and (2) are continuous state equations, but in digital control, sampling is performed at the MT, and the input is zero-order held (the input value at the time of sampling is held as it is). 2) Since 2 is converted to discrete time,
It becomes as shown in the following equations (3) and (4).

X (i + l) = [A] x (tl+B u
(il ---(3)y(1)=C'X(i)
・・・・・・・・・・・・・・・(4)
Here, X (11 is X (il, that is, X
(iT,), and similarly, u (') s y bl indicates u (1) s Y m at iT, time.

(3) Apply state feed packing to the controlled object represented by 2, and obtain u fit = −K ”X (1)
By setting ・・・・・・・・・・・・・・・(6), the optimal regulator
) system is constructed. Here, K is a feedback gain, which is composed of an n-th order vector.

This feedback gain has an evaluation function [Q] given by the following equation (7): n, xn coefficient matrix Rs: 1 It is obtained from equation (9).

K= (Rs+B" [P co B)-B"
[P] [A] [P] = [Q] +
[A co' [P] [A co
(a) [A] ” [P] B (Rs +BT [P] B) - BT [P] [A] The first term of the evaluation function J represents the penalty for the deviation from the origin of the state vector , the second term is the input u
If the coefficients [CB and Rs are set as a penalty to prevent fl) from becoming large, the feedback gain K of the optimal regulator can be uniquely determined from (a) 2.

In the above explanation, it is assumed that the state vector X fi) can be observed, but in actual state feedbank control, only a part of the state vector Instead, an observer (observer) that estimates the state vector X(1)
) is used. This observer is expressed by the following equation (9).

Z (il1) = [A co Z (11+
B u (il - (9a) il1))...
(9c) Here, Z (1) is the state estimate, F is the observer gain, and y (1) is the output estimate. Furthermore, (9b)
, Equation (9c) is equivalent to when considered at one time, but (9a), (9b),
In order to be able to calculate variables in the order of equation (9c), i+1
I'm thinking in terms of time.

Using this observer, u fit = −K TZ (i) ・・
... An optimal regulator system is constructed by setting αω.

The observer gain F in equation (9) is the dual system Xd (i
l1) = EA co” Xdflll+CT u
For d(1) . . . -αω, it is determined as F that minimizes the evaluation function Jd given by the following (2) using the same procedure as for determining the state feedback gain.

[Qd]: nxn coefficient matrix Rds: lXl coefficient matrix That is, coefficient spacing When the coefficients [Qd] and Rds of this evaluation function Jd are set, the observer gain F is obtained from the following α equation.

F= (Rds+C[Pdl C') C[
Pdl [A,] '[Pdl = [Qd]
+ [A] [Pdl [A] ”-[A
[Pdl C' ([Rd+C[Pdl C
"l-'C[Pdl[A]" FIG. 9 shows a digital servo control device equipped with the optimal regulator obtained in this manner and an observer for estimating the internal state of the controlled object.

In FIG. 9, 20 is a digital servo control device,
An optimal regulator 21 having a feedback gain K and an observer 22 are provided inside. 23 is a controlled object which receives input u (11) and generates output y(1).

In the observer 22, 221 is a B calculation unit, and input u
(1) That is, the vector B is applied to the output of the optimal regulator 21.
Multiply by 222 is an A calculation unit, which calculates the estimated state quantity Z (1
) is multiplied by matrix [A]. 223 is an adder which adds the calculation outputs of the B calculation unit 221 and the A calculation unit 222 and calculates Z (
i+1) (see equation (9a)).

224 is a delay calculation unit which inputs and outputs from the adder 223.

225 is a cT calculation unit which multiplies Z(1) input from the delay calculation unit 224 by vector cT to calculate CTZ(1), and outputs this as an output estimated value y(1) (
9b)).

226 is an adder that outputs the difference between the output y(1) of the controlled object 23 and the output y(1) of the cT calculation unit 225. 227 is F
In the arithmetic unit, the output of the adder 226 (y (11-y (1
)) is multiplied by the observer gain [F]. 228 is an adder that adds the output Z (11) of the delay calculation section 224 and the output F (>'(1)-y(i)) of the F calculation section 227 and adds it to the state optimal regulator 21 (see formula (9C)) ).

The optimal regulator 21 multiplies Z (+1) input from the observer 22 by a feedback gain "-" to generate an input U(1) to the controlled object 23.

[Problem that the invention seeks to solve]

In the conventional configuration method of the optimal regulator, if (7) and the coefficients [Q], Rs, [Qdco, Rds are given, the feedback gain K and the observer gain can be mechanically calculated from the formula (a) and the zero-turbine formula. I was able to find F.

Since Equation (a) and measurement for determining each gain K and F are determinant equations, it would take a lot of time to solve them by hand, so they are solved using a computer. However, even when solving with a computer, it generally requires repeated calculations, so
Although it is faster than when done manually, it takes a considerable amount of time to solve on an inexpensive computer. If it is necessary to solve the problem quickly, it is necessary to use an expensive computer with high calculation speed.

Furthermore, in an actual digital servo control device, when the gain G of the controlled object or the sampling frequency MT3 is changed, it is necessary to re-solve equations (a) and Q3 each time. Furthermore, in order to investigate the characteristics of the control system and realize the desired response characteristics, the coefficients [Q
] , Rs , [Qd] , and Rds to adjust each gain K and F, it is necessary to resolve Equation (a) and Equation 01 each time.

For this reason, there was a problem in that it took a lot of time to calculate the feedback gain K and observer gain F of the conventional optimal regulator. Furthermore, there is a problem in that an expensive computer for high-speed calculation is required if each gain is to be calculated in a short period of time.

The present invention is applicable to an object such as a DC motor in which the manipulated variable and the controlled variable have second-order integral characteristics, that is, the transfer function P fsl is G, /S
To provide a gain setting method for a digital servo control device which is improved so that the feedback gain and observer gain of the digital servo control device equipped with an optimum regulator and an observer can be easily calculated, with the object being controlled as follows. With the goal.

[Means for solving problems]

First, the principle of the present invention will be explained with reference to FIGS. 2 to 6.

The transfer function P (51) of a controlled object in which the manipulated variable and the constraint 4111ffi have second-order integral characteristics like a DC motor is expressed by the following equation (141).

P(3)=G,/S", G, Nigain -04
3 Now, the time unit of gain G is the sampling period T
, then the gain g in this unit is expressed by the following 0 equations.

g=Ts”×Gs...
...αω First, consider the case where g = 1, and in that case, the output y (t) of the controlled object and its time derivative are expressed as the state variable
2(t) and x+(t), and furthermore, let [Ac1 be [Ac
1. If B is B and CT is CT, the above equations (11 and (2)) become as shown in the following 00 and a power test.

・・・・・・0[9 Since sampling is done at time 1, the above (3) and (4)
) formula becomes the following 08) and 0ω.

...If an integrator is added to eliminate the steady-state deviation, the αω equation becomes the following I20) equation.

(2II) Here, in the present invention, it is not an essential requirement to provide such an integrator.

Next, if [Q 3 and R3 of the evaluation function J in equation (7) are set, the feedback gain corresponding to each [Q] and Rs can be found by solving equation (a). [Q] and R for selecting the optimal feedback gain K
There are various ways to set s, but for example, set [Q] to the following (2
By fixing the value shown in equation 1), that is, and solving equation (a) by varying Rs, the feedback gain K in each case can be easily obtained.

Figure 2 shows each feedback gain K (k+, 2
, and 3) are shown in a table.

Similarly, if [Qdl and Rds of the evaluation function Jd of the hit two are set, the observer gain F corresponding to each [Qdl and Rds can be obtained by solving the αω equation.

In this case as well, [Qdl is fixed at the value shown in the following equation (22), that is, by varying Rds (to solve equation 131 (
By doing so, the observer gain F in each case can be easily determined. Figure 3 shows this fixed [Qdl
Each observer gain F when changing Rs with respect to
(El, [2) is shown in a table.

Select one set of feedback gain and observer gain from each feed bank gain and observer gain table obtained in this way,
The response characteristics in each case are observed, and the feedback gain and observer gain are set to match the desired response characteristics.

FIG. 4 is a block diagram showing the configuration of a digital servo control device using the feedback gain K and observer gain F obtained in this manner. or,
The constraint jl1 equation in FIG. 4 is shown in the following equation (23).

e (1) = y (1) −r (i)
−・−・・・・・・(23a) w(1)=w (i −
1) + e(1) -----(23c)Z (i
+ 1) = [A] Z (1) + Bufil +
+ (23e) Here, K1□ is the first . In the second element, ,k.

The target value, e (1) is the error, and w is the integral amount.

In addition, regarding the value, time i+1 is considered so that variable calculations can be performed in the order of (23a) to (23f).

In FIG. 4, reference numeral 10 denotes a digital servo control device, which includes an optimal regulator 11, an observer 12, an adder 141, and an integrator 142.

15 is the controlled object, a transfer function with a gain of 1 (1/S2)
It has a characteristic expressed by , and receives a manipulated variable (input) u(1) and generates a controlled variable (output) y(i).

In the controlled object 15, 151 is a θ-order hold circuit that holds the value of the sampling point as it is, 152 is a characteristic instruction section that indicates the transfer function of the controlled object 15, and 153 is a sampler that performs sampling in unit time 1.

In the digital servo control device 10, the adder 141
is the error e(1) of the target value r (il and output y fi)
is generated (see equation (23a)).

The integrator 142 generates an integral output w(1), which is the error e(i) plus the integral value W(i-1) of one sample period before, and applies it to the optimal regulator 11 (in the observer 12 using equation (23c)) , 121 is a B calculation unit, and input u
(1) That is, the output of the optimal regulator 11 is multiplied by the vector B. 122 is an A calculation unit that multiplies the estimated state value Z(1) by the matrix [A]. 123 is an adder, and B calculation unit 1
21 and the calculation output of the A calculation unit 122, Z (i+
1) ((23e) Equation 124 is a delay calculation unit that delays z (i+1) input from the adder 123 by unit time "1" and outputs Z (i).125
is the C7 calculation unit, which calculates Z(
i+1), this is output as the estimated output y(i+1) (see equation (23f)).

126 is an adder, and y inputted from the cT calculation unit 125
(11) and e (1) input from the adder 141. 127 is an F calculation unit, which multiplies the observer gain F by the rule (e (i) - y () input from the adder 126). .128 is an adder, which inputs Z (i-1) inputted from the delay calculation unit 124 and the F calculation unit △
2 teZ (1)-Z (11+ F (e (1) -y
(Output the old and add it to the optimal regulator 11 ( (
23b)).

In the optimal regulator 11, 111 is a three-calculation unit that multiplies Z(1) input from the integrator 142 by +z.

The negative values of each input from the calculator 112 are added and input to the input U5 (see equation (23d)).

The above describes how to configure a digital servo control device when the gain of the transfer function of the controlled object is ``1'' and the sampling period T is ``1'' per unit time.Next, Based on this configuration method, see Figures 5 and 6 for a configuration method of a digital servo control device when the gain of the transfer function is g (≠1) and the sampling period is T, (≠1). and explain.

FIG. 5(A) is simply a rewrite of FIG. 4.

If a 1/g calculating section 154 is added to the controlled object 15 in FIG. 5(A) as shown in FIG. 5(B), and the transfer function of the characteristic indicating section 152A is set as "g/s", then 5
Figures (A) and (B) are equivalent, and the transfer function of the controlled object 15 is 1/S2.

In FIG. 5(B), if the 1/g calculation unit 154 in the controlled object 15 is moved to the digital servo control device 10 side and equivalently converted using a known block conversion method, the result is as shown in FIG. 6(B).
A digital servo control system having the configuration of A) is obtained.

In this digital servo control system, the controlled object 15
The transfer function of is g/SZ. The feedback gain of the optimal regulator IIA is the feedback gain of FIG. 5(A), that is, the feedback gain of FIG.
A g calculation unit 143 that multiplies g is inserted in the path that is fed from the output side of A to the observer 2. This g
When the calculation unit 143 is incorporated into the observer gain B calculation unit 121, equivalent conversion is performed as shown in FIG. 6(B).

From the above, since g=Ts G* (see the α expression), generally the sampling period is T and the transfer function G
In a digital servo control system for a controlled object having a gain of "1" as shown in FIG. 4, the optimal regulator feedback gain is l/T,G.

The argument that the observer gains of the observers are the same and the multiplier B of the B calculation unit is T, G, or more can be further generalized as follows.

■ Sampling frequency MTl of digital servo control device
is TSO, and when the gain G8 of the controlled object is Gso, the optimal regulator feedback gain 0 and the observer gain Fo are determined in advance.

■ At that time, when the sampling period T is Tsl and the gain G of the controlled object is GtI, the feed bank gain of the optimal regulator is 1, and the observer gain is Fl, then F+=F.

are required respectively.

The present invention is designed to set the optimal regulator feedback gain and observer gain of a digital servo control device based on such a principle. Hereinafter, the configuration of the present invention will be explained with reference to FIG. FIG. 1 is a block diagram showing the basic configuration of the present invention.

In FIG. 1, 10 is a digital servo control device,
An optimal regulator 11, an observer 12, and a gain setting device 13 are provided inside.

r is the target i.

Reference numeral 15 denotes a controlled object, in which the control amount (
Output) y is the second-order integral characteristic, that is, the transfer function P
(S)=G,/S” (G is the gain of the transfer function).

The optimal regulator 11 works to make the difference e between the target value r and the controlled amount zero. The observer 12 estimates the internal state of the controlled object 15.

In the gain setting device 13, 131 is a feedback gain table, in which at least one set of feedback gains Ko of the optimal regulator 11 is set when the sampling period Ts of the digital servo control device 10 is Tto and the gain G of the controlled object 15 is GsO. Stored.

Reference numeral 132 is an observer gain table, which indicates the observer gain F of the ρ observer 12 when the sampling period of the digital servo control device 10 is Tso and the gain of the controlled object 15 is G g Q. is small < t, IIJ1 is stored.

133 is a gain setting section, which is connected to the digital servo control device 1;
The feedback gain of the optimal regulator 11 and the observer gain F1 when the sampling period of 0 is T□ and the gain of the controlled object 15 is Gil, and each gain K of the feedback gain table 131 and the observer gain table 132. and Fo, and set the optimum regulator 1 and observer 12.

Note that part or all of the gain setting device 13 may be provided outside the digital servo control device 10.

[For production]

The sampling period T of the digital servo control device 10,
is Ts+, and the gain G of the transfer function of the controlled object 15 is
is G□, the gain setting unit 133 calculates the feed hack gain KI of the optimal regulator 11 from the following equation based on the feedback gain stored in the feedback gain table 131 as 0.

Further, the gain setting unit 133 sets the observer gain Fo stored in the observer gain table 132 when the sampling period T is Tit and the gain G of the transfer function is G.
Set as the observer gain F1 when il.

If the feedback gain table 131 stores a plurality of sets of feedback gains, 01 to KO, and the observer gain table 132 stores a plurality of observer gains Fl to FOn, then the For one set of feedback gains, a feedback gain Gli is calculated for H using the machining allowance. Also, the feedback gain G in the observer gain table 132. Observer gain FOi corresponding to i is observer gain F. , is set as .

Each feedback gain and observer gain (K(11, Fo+; Koz, Fo
2+~;KIll, , Fo, , ), the response characteristics of the digital servo control system are observed, and the feed bank gain and observer gain that provide the desired response characteristics are selected.

By doing the above, any sampling period T
It is possible to simply calculate the feed bank gain and observer gain for sI and the gain aSI of the controlled object, and easily realize a digital servo control system having desired response characteristics.

[First embodiment] A first embodiment of the present invention will be described with reference to FIG.

FIG. 7 is a block diagram showing the configuration of the first embodiment of the present invention.

The first embodiment embodies the gain setting method of the digital servo control device described above with reference to FIGS. 4 to 6.

In FIG. 7, a digital servo control iB device 10,
The optimal regulator 11, observer 12, gain setting device 13, feed bank gain table 131, observer gain table 132, gain setting section 133, and controlled object 15 are as described in FIGS. 1 and 4.

The gain setting device 13 is internally equipped with tables 131 and 132 for feedback gain K and observer gain F as shown in FIGS. 2 and 3. The gain setting section 133 includes a feedback gain calculation circuit 134.

Now, the sampling period TI, the gain G of the controlled object 15
1. Coefficient Rs ((
7) Refer to formula, Q is fixed), evaluation function J of observer 12
When the coefficient Rds of d (see equation (2), Qd is fixed) is given, the gain setting unit 133 looks up the feedback gain K in the feedback gain table 131 from the coefficient R.

Next, the feedback gain calculation circuit 134 calculates
The feedback gain setting unit 133 of the optimal regulator 11 looks up the observer gain F from the coefficient Rd, and sets this F as the observer gain F of the observer 12.

In other words, it is complicated and time-consuming like the conventional gain setting method (
There is no need to solve equations a) and 03) 2, and the feedback gain and observer gain can be immediately set by the simple calculation shown in (24) 2 below.

F=F Also, the control equation for the digital servo control device 10 at this time is expressed by the following equation (25) based on the above equation (23) and the matters explained in FIGS. 4 to 6. .

e (1)= )' (il −r (1)
=------...(25a)Zfl)=Z(
i) + F (e(1)-)'(i)) -----
(256)w(1)=w(i-1)+e(11...
... (25c) ufll=-, z IZ(
+l] −, w(j) −(25d)B u
(i) --(25e)8 Equation (25f) is y(+1-cT
Z (equivalent to 11, but (25a) ~ (25f)
The time i+1 is considered so that the variables can be calculated in the order of .

FIG. 7 shows a concrete example of the digital servo control system expressed by equation (25). Since its configuration is the same as that shown in Figure 4, the same components are given the same reference numerals, and corresponding components have the suffix A after the numerical code.
I will explain it by attaching it.

The controlled object 15 is a transfer function of gain Gs (Gs/S2)
It has the characteristics expressed as , and generates the control N (output) y (1) in response to the manipulated variable (input) u (1). 151 is O
The next hold circuit, 152A, is a characteristic instruction unit that indicates the transfer function of the controlled object 15, and 153A is a sampler that performs sampling at a period T.

In the digital servo control device 0, the adder 141
is the error e(1) between the target value r(1) and the output)F(il
) is generated (see equation (25a)).

The integrator 142 generates an integral output W(1) obtained by adding the integral value W (i-1) of one sample period before to the error e (11) and adds it to the optimal regulator 11 ((25c) Equation 2
．． 1A, the input u (i), that is, the calculation unit 122 of the optimal regulator 11 inputs the estimated state quantity [Z (11F has a matrix [A
](il1) (see equation (25e)).

The delay calculation unit 124 receives the input z from the adder 123.
(il1) by one sampling period and Z
Output (i). The CT calculation unit 125 includes the delay calculation unit 1
The vector is output to Z (i) input from 24 as the output estimated value y (++1) (see equation (25f)).

The adder 126 receives y(
1) and the e_filO input from the adder 141. The F calculation section 127A multiplies (e (i) - Y (11) input from the adder 126 by the observer gain F. The adder 128 multiplies Z (i-1) input from the delay calculation section 124. is added to the calculation unit 127 and the optimal regulator 11 (see equation (25b)).

In the optimal regulator 11, the k3 calculation unit 111A multiplies w (11) input from the integrator 142 by . The Kl! calculation unit 112A multiplies Z (1) input from the observer by KI! .The adder 113 is
k, the negative values of each input from the arithmetic unit 111A and the KI2 arithmetic unit 112A are added to obtain an input u (1) = K + t
Z (i) k 3 W (1) is generated and input to the controlled object 15 (see equation (25d)).

As described above, the feedback gain K and observer gain F of the optimal regulator corresponding to the coefficients Rs and Rds of the given evaluation functions J and Jd can be immediately obtained by simple calculation. Coefficients Rs and Rds
is changed to find the corresponding feedback gain K and observer gain F, the response characteristics of the control system in each case are observed, and the feedback gain K and observer gain F that match the desired response characteristics are selected.

[Second Embodiment] The second embodiment simplifies the configuration of the observer in the first embodiment, and also uses a function generator to generate the control amount (output) y(
1) target trajectory and its second derivative acceleration a (11
The response characteristics of the control system are improved by adding a feedforward ring Ts Gs a(i) based on this acceleration a (due to R).

[A] in equation (25), which is the control equation of the first embodiment.

Then, the control equation expressed by the following equation (26) is obtained.

e (1)= y (1) −r (i)
−...(26a)z(1)=[Ar1 Z (i−
1)+i3 f u (i −1) +F e(11・
...(26b) (26)w(i)=w(i-
1) +(1) −(26c)u(i)=
K+zZ(il ks w(i) --(26
d) Furthermore, equation (26b) is calculated as Z(i
+1)=[Ar1 Z(ll+B f u(i)+F
e (i + l), but (26a) to (26
We are considering one time so that the variables can be calculated in the order of d).

here It is.

FIG. 8 shows a concrete example of the digital servo control system expressed by equations (26) and (27).

In the configuration, the same components as in the first embodiment are designated by the same reference numerals, and corresponding components are described with a suffix B added after the numerical symbol.

In FIG. 8, a digital servo control device 101, an optimal regulator 11, a k3 calculation unit 111A, an Lx calculation unit 1
12A, adder 113, gain setting device 13, feedback gain table 131, observer gain table 132, feedback gain calculation circuit 134, adder 141, integrator 142, controlled object 15.0-order hold circuit 151, characteristic instruction section 152A, The sampler 153A has a configuration common to that of the first embodiment shown in FIG.

In the gain setting unit 133B of the gain setting device 13, the feedback gain calculation circuit 134 calculates ((27
a)), 135 is an AtBt arithmetic circuit, and f of F read out from the observer gain table 132, and f
z (see formula (27b)), (27c) and (2
7d) Calculate [, +l] and Bf shown in the formula.

In the digital servo control device 10, 144 is a function generator that generates a target trajectory r(i) for operating the controlled object 15.
And an acceleration a(i) which is the second derivative of this r (1) is generated. 145 is a feedforward unit which multiplies the acceleration a(1) inputted from the function generator 144 by T2C. 146 is an adder that adds u(1) inputted from the optimal regulator 11 and Ts Gi −a (1) inputted from the feedforward section, and inputs the result to the controlled object 15.

In the observer 121B, 12B is a Bf calculation unit,
A to the output u(1) of the optimal regulator 11.

The eAf calculation unit 122B, which multiplies the vector B sent by the calculation circuit 135, calculates the estimated state value Z (i)
The matrix [At
Multiply by The adder 123 includes B, arithmetic unit 121 and A.
The calculation outputs of the t calculation unit 122B are added to output z(i+1).

The delay calculation unit 124 receives the input “z(i
+1) by one sampling period. The F calculation unit 127B receives e(11(=
)'fl) -r(i), see equation (26a)) is multiplied by the observer gain F. The adder 128 adds the inputs from the delay calculation unit 124 and the F calculation unit 127B to calculate Z.
(il= [At] Z (+ 1) + 3゜u (
t1) +Fe(1) is output and added to the optimal regulator 11 (see equation (26b)).

The integrator 142 receives the error e input from the adder 141.
(It generates an integral output w (1) obtained by adding the integral value w (i-1) of one sampling period before and applies it to the optimal regulator 11 (see equation (26c)).

In the optimal regulator 11, the k3 calculation unit 111A multiplies W(1) input from the integrator 142 by . KVI! The calculation unit 112A performs KI! on Z (1) input from the observer! Multiply by Adder 11
3 adds the negative value of each input from the □ calculation unit 112A to the k calculation units 111A and 112A to obtain u (il = −KIZ
Generate Z(1) ks w(1) ((26d)
(see formula).

The adder 146 adds the inputs from the feedforward unit 145 and the adder 113 and inputs the result to the controlled object 15 .

By doing the above, the observer 12B of the second embodiment can be replaced with the observer 12B of the first embodiment shown in FIG.
Since the C7 arithmetic unit 125 and the adder 126 are not required compared to the above, the configuration of the observer can be simplified.

Furthermore, since the acceleration a (1) is included in the control amount, the stability and coordination of response characteristics can be improved.

〔Effect of the invention〕

As explained above, according to the present invention, the following effects can be obtained.

(a) A desired feedback gain and observer gain can be obtained by a simple calculation of converting the basic feedback gain and observer gain stored in the table.

(b) Since it is easy to calculate the feedback gain and observer gain, it is possible to easily realize a digital servo control system having desired response characteristics corresponding to the characteristics of the controlled object.

[Brief explanation of drawings]

Fig. 1...Explanatory diagram of the basic configuration of the present invention, Fig. 2...
An explanatory diagram of the feedback gain table used in the present invention. Figure 3: An explanatory diagram of the observer gain table used in the present invention. Figure 4: Explanation of the principle of the present invention when the gain of the controlled object is 1. Figure 5: An explanatory diagram of the principle of the present invention when the gain of the controlled object is not 1, Figure 6: An explanatory diagram of a control system obtained by equivalently converting Figure 5, Figure 7: This figure Explanatory diagram of the first embodiment of the invention, Fig. 8...
・Explanatory diagram of the second embodiment of the present invention, FIG. 9...Explanatory diagram of a conventional digital servo control system, In FIGS. 1 to 8, 10...Digital servo control device, 11, 11A・
...Optimum regulator, 12. 12B... Observer, 13... Gain setting device, 131... Feedback gain table, 132... Observer gain table, 133, 133B... Gain setting section, 15.
...Controlled object. Patent applicant: Fujitsu F-Party Co., Ltd./)k, f-ishi j or Figure 1

Claims (2)

[Claims] (1) The controlled object (15) is an object in which the manipulated variable and the controlled amount have second-order integral characteristics, and the optimal regulator (11) that works to zero the difference between the target value and the controlled amount and the controlled object (15)
) In the gain setting method of a digital servo control device (10) equipped with an observer (12) that estimates the internal state of the control object (15), (a) the sampling period of the digital servo control device (10) is T_s_o, (b) A feedback gain table (131) in which at least one set of feedback gains K_o of the optimal regulator 11 when the gain G_s_o is stored; ) gain is G
(c) an observer gain table (132) storing at least one set of observer gains F_o of the observer (12) when _s_o; ) gain is G
The feedback gain of the optimal regulator (11) when __g_l, and the observer gain F_l,
A digital device comprising: a gain setting unit (133) that calculates based on each gain K_o and F_o of the feedback gain table 131 and the observer gain table 132 and sets it to the optimal regulator (11) and observer (12). Gain setting method for servo control equipment. (2) The gain setting section (133) K_l=K_o×(T_g_o/T_g_l)^2×
A gain setting method for a digital servo control device according to claim 1, wherein the feedback gains K_l and F_l are calculated by (G_s_o/G_s_l)F_l=F_o.