System of control objects identification

FIELD: information technologies.

SUBSTANCE: system comprises a model of a control object, the third block of comparison and a block of calculation of parameters of an object model, the inlet of which is connected with an output of the operator controller, the outlet of the model parameters calculation block is connected to the second output of the control object identification system and is connected to the first inlet of the comparison object model, the second and third inlets of which are connected, accordingly, with the inlet and outlet of the control object; the first, second and third outlets of the control object model are connected, accordingly, to the first inlet of the third block of comparison, to the second and third inlets of the operator controller, the second inlet of the third block of comparison is connected with the outlet of the control object, and the outlet of the third comparison block is connected to the second inlet of the second comparison block and to the inlet of the block of generation of control error properties.

EFFECT: higher accuracy of control objects identification.

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The invention relates to automatic control and can be used in automatic control systems dynamic non-stationary objects, mathematical models that contain variables, operators, and/or parameters.

Examples of such objects can serve as a cyclone combustion chamber for burning a mixture of coal and water slurry fuel in a process which is susceptible to the influence of uncontrolled disturbances caused, in particular, changes in the quality characteristics of coal-water slurry fuel, violations of the sputtering process, the aging of the structural elements of the furnace, which leads to a change in the dynamics of thermal processes and, consequently, the dynamics of the channels of transformation of material and energy flows. Furthermore, this object is a flexible structure, which varies, for example, when switching setup to work with supply and without a supply of coal that along with the change in the object structure management entails changes its mathematical model.

For the identification of control objects known adaptive identifier [1], containing the first object model, the first block of comparison, the adder, the first delay unit, the second model of the object, the second block comparison, series reg the system, extrapolator and the second delay unit, connected the output to the first input of the second model object and the second unit of comparison, a second input connected to the output of the controller, and the output to the first input of the first object model, the output of which is connected to the first input of the adder, the first and second inputs of the first unit of comparison is connected respectively with the output of the adder and the first input of the identifier, a second input connected through a first delay unit with a second input of the first and second object models, the outputs of which are connected respectively with the first and second inputs of the adder, the output of the first unit of comparison is connected to the input of the controller.

When the ID in the model is a closed-loop system composed of the adder, the first object model, controller, first and second units of comparison, is restored with time-delay estimation of the transmission factor of the object. This estimate is extrapolated to the current time, and is adjusted for the errors of extrapolation, which is defined in the circuit containing the second delay unit and the second Comparer.

A disadvantage of the known identifier is its low functionality, as it is aimed to determine only the evaluation of the transmission factor of the dynamic object.

The closest t is nicesly nature of the proposed identification system objects control is the control system [2], contains the object control series unit, the first unit of comparison, the processing unit properties throttling errors, the second block of the comparison operator, the regulator, cross regulator, a second input connected to the output of the first unit of comparison, the output coordinate of the encoder is connected to the input of the control object, the output of which is connected to the second input of the first unit of comparison, the output of which is connected to the second input of the second unit of comparison, the output of the control object connected to the system output.

When the operation of the control system depending on the error signal at the output of the first unit comparing a coordinate regulator produced a regulatory impact, for example, to ensure the properties specified error control output exposure control object affected by unknown disturbances. If the error coordinate regulation does not correspond to the set of its properties, the signal which is generated at the output of the block-forming properties of the errors of regulation, the operator controller produces the control actions on the changes in the structure or values of the parameters of the control law implemented in the coordinate controller.

The disadvantage of this system is the low functionality as it is not intended to perform the function of identification of non-stationary object, i.e. assessment of the structure and values of parameters of the mathematical model.

The objective of the invention is the extension of system functionality.

This object is achieved in that in a system containing unit, connected in series control object, the first block of comparison, the coordinate controller, connected in series forming unit properties throttling errors, the second block of the comparison operator, the regulator, and the output coordinate of the encoder is connected to the input of the control object whose output is the first output system, the output of the generator is connected to the second input of the first unit of comparison, introduced the model of the control object, the third block comparison and calculation of parameters of the model object, the input connected to the output of the operator of the controller, the unit output calculation of the model parameters is connected to the second output system identification control object and connected to the first input of the model of the control object, the second and third inputs of which are connected respectively with the inlet and outlet of the control object; first, second and third outputs of the model of the control object connected respectively to the first input of the third block of comparison, the second and third inputs of the operator of the controller, the second input of the third Comparer coupled to the output of the object of control is to be placed, and the output of the third unit of comparison is connected to the second input of the second unit of comparison and to the input of the processing unit properties throttling errors.

The model of the control object includes serially connected first delay block, the fourth block of comparison, the model of the object in increments and the fifth block of comparison, a second delay unit, an input connected to the third input to the model of the control object, and the output of the second delay unit connected to the second input of the fifth block of comparison, the output of which is connected to the first output model of the control object, model object in increments connected with the second output model of the control object, the third output of which is connected to the first input of the model object in increments, the second input of the fourth unit of comparison is connected to the input of the first delay unit and the second input to the model control object, the second input to the model object in increments connected to the first input of the model of the control object, which is connected to the unit output calculation of the model parameters.

Operator controller includes serially connected first block override signal, the first block squaring, the adder, the first unit, the first unit of the multiplication, the first block of integration and the first scaling unit, connected in series the differentiation block, the second the lock override signal, the second unit, the second block multiplication, the second block of integration and the second scaling block, the second block squaring, the input connected to the output of the second unit of the override signal, and its output terminal connected to the second input of the adder, the first operator input controller connected to the output of the second unit of comparison is connected to the second inputs of the first and second multiplier units respectively, the second input of the operator controller connected to the second output of the model of the control object connected to the input of the differentiation block, the third operator input controller connected to the third output model of the control object connected to the input of the first block override signal, the output of which is connected to a second input of the first unit, the first input connected to the second input of the second unit, the first input of which is connected to the input of the second block squaring, the outputs of the first and second scaling units connected to the output of the operator controller and are components of its output signal connected to the input of the calculation of the model parameters.

Figure 1 shows the block diagram of the identification system of the control object. Figure 1 shows the following notation:

u(t) is the signal of the control effect;

y(t) is the signal on the output is ostatnie control object;

k_j(t);$$j=\stackrel{}{\mathrm{1,}J}$$signal about the estimates of the coefficients in the model of the control object;

J is the number of these coefficients;

t is continuous time.

Figure 2 presents the block diagram model of the control object, which is a variant of implementation of the model of the control object 5. Figure 2 shows the following notation:

y^M(t) signal on the output impact model of the control object;

δu(t) - difference signals u(t) and u(t-τ);

δy(t) is the signal on the output impact model of the control object in increments.

Figure 3 shows an example block diagram of the operator controller that implements the law of(16), (17), (10), (11). Figure 3 shows the following notation:

σ(t) is the signal about the variance of the error object model ε_y(t) of the reference$${\epsilon }_y^{*}(t)$$on the properties of the error operator regulation;

$$k_1^l(t)$$;$$k_2^l(t)$$ signals on the current estimates of the coefficients of the linear parametric model (9).

System identification of control objects includes a control object 1, the coordinate controller 2, the first block 3 comparison unit 4, model 5 control object, the third block 6 comparison unit 7 calculation of the model parameters, the operator controller 8, the second block 9 comparison unit 10 forming properties throttling errors.

The model of the control object contains the first delay block 11, the fourth block of 12 comparisons, the model 13 of the object in increments, the fifth block 14 comparison and the second unit 15 delays.

Operator the controller includes a first block 16 override signal, the first unit 17 squaring first block 18 dividing the first block 19 multiplication, the adder 20, the first block 21 of integration, the first scaling block 22, block 23 of differentiation, the second block 24 override signal, the second block 25 squaring, the second block 26 division, the second block 27 multiplication, the second block 28 of integration and the second scaling unit 29.

System identification of control objects is as follows. The signal y(t) on the output effects of the control object 1 is fed by the first entry in the first block 3 comparison, where it is compared with the signal y^*(t) about the job output variable of the object 1, which comes from wychodzacych 4 to the second input of the first block 3 comparison. The output signal ε(t) of the first block 3 comparison comes in a coordinate regulator 2, the output of which appears the signal u(t) on the control effect produced in accordance with the algorithm f_R{·} the coordinate regulation

$$\text{u(t)}={\text{f}}_{\text{R}}\text{{}{\epsilon }_{\text{u}}(t)\}.(1)$$

The signal u(t) with the output coordinate of the encoder 2 is fed to the second input of the model 5 control object and to the input of the control object 1, where he provides with the required accuracy compensation of deviations of the signals y(t) from y^*(t). Simultaneously with the signal u(t) the input to the model 5 control object signal y(t), which is the calculation of the signal y^M(t) on the output impact model 5 control object.

The functioning of the model 5 control object is performed as follows. The signal u(t) with the output coordinate of the encoder 2 is delayed in the first block 11 delay time delay time is τ and is subtracted from the signal u(t). The resulting difference signal δu(t) is supplied to the first input of the model 13 of the object in increments, to the second input of which is fed from the output of block 7 of the calculation of the model parameters the signal on the current estimates of its coefficientsa₁(t). The signal δy(t) with the model output 13 of the object in increments, describing her reaction to the increment δu(t), is summarized in the fifth block 14 comparison with pre-detainees at time τ in the second unit 15 delays the output signal y(t-τ) of the control object 1, forming the first output models 5 object control signal y^M(t).

The law of models 5 object management in General is represented by the following expressions

$${\text{y}}^{\text{M}}\text{(t)}=\text{y(t-a}t\text{)}+\delta \text{y(t);}\left(\text{2}\right)$$

$$\delta y(t)=\phi \{\delta u_j(t);k_j(t)\};j=\stackrel{}{\mathrm{1,}J};(4)$$

$$\delta u(t)=u(t)-u(t-t);(5)$$

$$u(t-t=f_C\{u(t)\},\left(6\right)$$

where τ is the delay time of the signals u(t) and y(t);

f_C{·} operator delay signals at time τ;

φ{·) - operator model of the object in increments;

$$k_j(t);j=\stackrel{}{\mathrm{1,}J}$$- the coefficients of the model object in increments;

J is the number of coefficients.

In particular, the model (4), including nonlinear, can be presented in an easy to identify linear parametric form

$$\delta y(t)={\displaystyle \underset{j=1}{\overset{J^l}{\sum }}{k}_j^l(t)\delta u_j}$$

where$$k_j^l$$;$$j=\stackrel{}{\mathrm{1,}{J}^l}$$the coefficients of the linear parametric model of the object in increments;

J^l- the number of coefficients of the linear parametric model.

For example, if the model 13 of the object in increments presented in the form of linear differential equation of first order

$$T(t)\frac{d\delta y(t)}{dt}+\delta y(t)=k(t)\delta u(t),(8)$$

where T(t), k(t) are the current values of the estimates of the model parameters in increments: time constant and gain, respectively, which are components of the signal k_j(t), the expression (7) will be

$$\delta y(t)=k_1^l(t)\delta u_1(t)+k_2^l(t)\delta u_2(t);\left(9\right)$$

$$\delta u_2(t)=\frac{d\delta y(t)}{dt}.(11)$$

The signal y^M(t) from the first output models 5 control object arrives at the first input of the third block of 6 comparisons, where it is subtracted from the signal y(t)received by the second I shall do the third unit 6 comparison with the output of the control object 1. The output signal ε_y(t) third Comparer 6, proportional to the difference signals from the output of the control object 1 y(t) and from the first output models 5 control object y^M(t), i.e.,

$${\epsilon }_y(t)=y(t)-y^M(t),(12)$$

flows through the second input to the second block 9 comparison and to the input unit 10 forming properties mistakes regulation, which implements the operator S{ε_y(t)}, reflecting in General, the job of the error properties of the operator control.

Alternatively, this task can be associated with the nature of the transition process errors ε_y(t) and, in particular, expressed using the ratio of the following form

$${\epsilon }_y^{*}(t)={\epsilon }_y(t)\cdot e^{-\alpha t},\left(13\right)$$

where α is a constant factor.

Signal$${\epsilon }_y^{*}(t)$$arrives at the first input to the second block 9 comparison, where it is compared with the signal ε_y(t), generating the output of the second unit 9 comparison signal

$$\sigma (t)={\epsilon }_y^{*}(t)-{\epsilon }_y(t),(14)$$

which arrives at the first input of the operator controller 8, the second and the third input of which receives signals δy(t) and δu(t) respectively from the second and third outputs of the model 5 control object.

The law of functioning of the operator controller 8, which can implement customlocale parametric functions of the regulator, in General represented by the following expressions

$$k_j(t)=f_{\mathrm{and}}\{\sigma (t);[\delta u_j(t)]\};j=\stackrel{}{\mathrm{1,}J};(15)$$

;

$$\sigma (t)={\epsilon }_y^{*}(t)-{\epsilon }_y(t)$$;

$${\epsilon }_y^{*}(t)=S\{{\epsilon }_y(t)\}$$;

ε_y(t)=y(t)-y^M(t)

where f_and{·} is the operator of the current estimation of the model coefficients in increments.</>

If the model 13 of the object in increments represented as expression (9), the expression (15) takes the following simple form

$$k_1^l(t)=\frac{1}{\theta }{\displaystyle \underset{t-\theta }{\overset{t}{\int }}\frac{\delta u_1(t)}{{\displaystyle \underset{j=1}{\overset{2}{\sum }}\delta u_j^2(t)}}}\cdot \sigma (t)dt;\left(16\right)$$

$$k_2^l(t)=\frac{1}{\theta }{\displaystyle \underset{t-\theta }{\overset{t}{\int }}\frac{\delta u_2(t)}{{\displaystyle \underset{j=1}{\overset{2}{\sum }}\delta u_j^2(t)}}}\cdot \sigma (t)dt;\left(17\right)$$

δu₁(t)=δu(t);

$$\delta u_2(t)=\frac{d\delta y(t)}{dt}$$

where θ is the interval of integration.

The operation of the operator of the regulator is as follows. The signal δu(t) from the third output model of the control object 5 is supplied by a third operator input controller in the first block 16 override signal and, after conversion in accordance with the expression (10) in the signal δu₁(t), enters the first block 17 squaring, forming at its output a signal proportional to the value of$$\delta u_1^2(t)$$that on the first input signal in the adder 20.

Simultaneously with the signal δu(t) signal δy(t a second model output 5 of the control object arrives at the second input of the operator control unit 23 of differentiation, at the output of which a signal is generated that is proportional to the value of the derivative of$$\frac{d\delta y(t)}{dt}$$, which, coming in the second block 24 override signal is converted in accordance with the expression (11) in the signal δu₂(t). The latter, acting in the second block 25 squaring, generates at its output a signal proportional to the value of$$\delta u_2^2(t)$$, through which the second input signal in the adder 20, where, being summarized in the course signal$$\delta u_1^2(t)$$produces the output of block 20 a signal proportional to$${\displaystyle \underset{j=1}{\overset{2}{\sum }}\delta u_j^2(t)}$$. This signal on the second input comes in blocks 18 and 26 divide, the output of which produces signals proportional to the values of$$\frac{\delta u1(t)}{{\displaystyle \underset{j=1}{\overset{2}{\sum }}\delta u_j^2(t)}}$$and$$\frac{\delta u_2(t)}{{\displaystyle \underset{j=1}{\overset{2}{\sum }}\delta u_j^2(t)}}$$respectively.

Simultaneously with the signals δu(t) and δy(t) through the first input of the operator controller to the second inputs of the first 19 and second 27 blocks the multiplication comes from the output of the second unit 9 comparison signal σ(t), is proportional to the deviation of the error model 5 object ε_y(t) from a signal$${\epsilon }_y^{*}(t)$$about the job on the properties of the error operator regulation, i.e

$$\sigma (t)={\epsilon }_y^{*}(t)-{\epsilon }_y(t).(18)$$

Signal values$${\epsilon }_y^{*}(t)$$determined in block 10 forming properties throttling errors. The output signals of the blocks 19 and 27 multiplying the received respectively in the first 21 and second 28 blocks of integration, and then in the first 22 and second 29 scaling units are multiplied by the value of$$\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$\theta $}\right.$$.

Thus, at the output of the first scaling unit 22 produces a signal proportional to the current estimate of the coefficient

$$k_1^l(t)=\frac{1}{\theta }{\displaystyle \underset{t-\theta }{\overset{t}{\int }}\frac{\delta u_1(t)}{{\displaystyle \underset{j=12}{\overset{}{\sum }}\delta u_j^2(t)}}}\cdot \sigma (t)dt$$,

which corresponds to the expression (16), and the output of the second scaling unit 29 is a signal proportional to

$$k_2^l(t)=\frac{1}{\theta }{\displaystyle \underset{t-\theta }{\overset{t}{\int }}\frac{\delta u_2(t)}{{\displaystyle \underset{j=1}{\overset{2}{\sum }}\delta u_j^2(t)}}}\cdot \sigma (t)dt$$,

which corresponds to the expression (17). These signals, as components of signal$$k_j^l(t)=\{k_1^l(t);k_2^l(t)\},$$ coming from the output of the operator controller 8 to the input unit 7 calculation of the model parameters, in which the current estimates of the coefficients of$$k_1^l(t)$$and$$k_2^l(t)$$linear parametric model (9) are translated into the coefficients of the model object in increments of (4). In particular, if this model is represented by the expression (8), the conversion is carried out according to the formula

$$k(t)=k_2^l(t);T(t)=-k_2^l(t).(19)$$

Current estimates of the coefficients in the model (8), which is a special case of the model volume is that the increments of (4), act as components of the signal k_j(t)={k(t);T(t)} of block 7 of the calculation of the model parameters in the model 13 of the object in increments, as one of the elements of the model of the control object. This ensures a continuous adjustment of the estimated coefficients of this model.

The introduction of new units and connections allows you to extend the functionality of the system identification of control objects, i.e. to evaluate the structure and values of parameters of the mathematical model of non-stationary object management. It also gives the opportunity to use this system for identification of linear and nonlinear control objects, models can lead to linear parametric form.

SOURCES of INFORMATION

1. SU 1365047 A1. 07.07.1986.

2. Emelyanov S.V., Korovin S. Kaliev New types of feedback: the Management of uncertainty. - M.: Nauka. Fizmatlit, 1997. - 352 S., S. 143, RES.

1. System identification of control objects containing unit, connected in series control object, the first block of comparison, the coordinate controller, connected in series forming unit properties throttling errors, the second block of the comparison operator, the regulator, the output coordinate of the encoder is connected to the input of the control object whose output is the first output system, the output of the generator is connected to the second I shall do the first block comparison characterized in that it introduced the model of the control object, the third block comparison and calculation of parameters of the model object, the input connected to the output of the operator of the controller, the unit output calculation of the model parameters is connected to the second output of the identification system of the control object and connected to the first input of the model of the control object, the second and third inputs of which are connected respectively with the inlet and outlet of the control object; first, second and third outputs of the model of the control object connected respectively to the first input of the third block of comparison, the second and third inputs of the operator of the controller, the second input of the third Comparer coupled to the output object control, and the output of the third unit of comparison is connected to the second input of the second unit of comparison and to the input of the processing unit properties throttling errors.

2. The system according to claim 1, characterized in that the model of the control object includes serially connected first delay block, the fourth block of comparison, the model of the object in increments and the fifth block of comparison, a second delay unit, an input connected to the third input to the model of the control object, and the output of the second delay unit connected to the second input of the fifth block of comparison, the output of which is connected to the first output of the plant model, the model output of the volume is the same in increments connected with the second output model of the control object, the third output of which is connected to the first input of the model object in increments, the second input of the fourth unit of comparison is connected to the input of the first delay unit and the second input to the model of the control object, the second input to the model object in increments connected to the first input of the model of the control object, which is connected to the unit output calculation of the model parameters.

3. The system according to claim 1, characterized in that the operator controller includes serially connected first block override signal, the first block squaring, the adder, the first unit, the first unit of the multiplication, the first block of integration and the first scaling unit, connected in series the differentiation block, the second block override signal, the second unit, the second block multiplication, the second block of integration and the second scaling block, the second block squaring, the input connected to the output of the second unit of the override signal, and its output terminal connected to the second input of the adder, the first operator input controller connected to the output of the second unit of comparison is connected to the second inputs of the first and second multiplier units respectively, the second input of the operator controller connected to the second output of the model of the control object connected to the input of the differentiation block, the third entrance is paratinga regulator, connected with the third output model of the control object connected to the input of the first unit of the override signal, the output of which is connected to the second input of the first unit, the first input connected to the second input of the second unit, the first input of which is connected to the input of the second block squaring, the outputs of the first and second scaling units connected to the output of the operator controller and are components of its output signal connected to the input of the calculation of the model parameters.