RU2571570C1 - Automatic control system and method - Google Patents

Abstract

FIELD: information technology.

SUBSTANCE: in an automatic control system, having a controller which is connected in series through an actuating mechanism to a controlled object, unlike the prototype, the actuating mechanism is a digital-to-analogue converter and the system further includes an analogue-to-digital converter connected between the output of the controlled object and the input of a controller, which consists of a command value setting device, connected in series to adders, the outputs of which are connected through a divider to an exponentiation unit, the output of which is the output of the controller, the inputs of which are the second inputs of the adders which serve for the output variable of the controlled object.

EFFECT: automatic control of systems in an adaptive range owing to adaptive signal estimation based on a program-controlled normalised measure.

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Description

The present invention relates to automation and can be used in cleanrooms to maintain a constant optimum temperature.

A known method of automatic control of systems, including the use of command and actual values of the output variables to regulate the managed system [Nosov GR and others. Automation and automation of mobile agricultural machinery. - K .: Higher School, 1984, p.171]. For its implementation, a device is known that includes the elements of transformation and amplification of the output variable of a controlled object connected in blocks, as well as a block for measuring the disturbed effect on a controlled object.

The disadvantage of this method and device is low efficiency due to insufficient accuracy of transient control at the required speed.

The prototype adopted a method of automatic control of systems [see RF patent No. 2153697, G05B 17/00, 2000, Furunzhiev RI], in which the output variable of the actuator is fed to the input of the managed object, measure the actual value of the output variable of the managed object, which together with the value of the output variable of the actuator and the command value the output variable of the controlled object is used to generate a control signal, which is fed to the input of the actuator, and additionally use negative feedback on the output variable ADDITIONAL mechanism that measure the velocity and acceleration of change of the actual value of the output variable controlled object and fed it to the input of block forming the desired properties of the motion of the output variable controlled object together with the actual value of the output variable controlled object and the value of the output variable of the actuator.

In the controller, which includes the elements of conversion and amplification of the signal speed of the controlled object combined into blocks, the channels for measuring the magnitude, speed and acceleration of the output variable of which are connected to the inputs of the controller, the output of which is connected to the input of the actuator, the output of the latter is connected to the input of the controlled object signs: measurement channels of the output variable of speed and acceleration of the controlled object are connected to the inputs of the block forming the desired motion properties of the output variable of the control object to be added.

Prototypes have significant drawbacks: the inability to automate in the adaptive range due to the need for manual tuning according to the subjective measure of assessment. This reduces the versatility of using the method and device and their effectiveness.

The technical task of the proposed solution is the automation of regulation by systems in the adaptive range due to adaptive signal estimation by software-controlled standardized measure.

The task is achieved by the fact that

1. in the method of automatic control of systems, in which the output variable of the actuator is fed to the input of the controlled object, the actual value of the output variable of the controlled object is measured, which, together with the command value of the input variable of the controlled object, is used to generate the control signal. The control signal is fed to the input of the actuator through the use of negative feedback on the output variable of the managed object. Unlike the prototype, the output variable of the controlled object in digital equivalent is fed to the input of the controller block, the control signal of which corresponds to the desired properties of the output variable of the controlled object and it is implemented by the multiplicatively symmetric error criterion, which acts as an automatic controller that adapts to the range by evaluating the actual values input and output variables to the normalized equivalent of their maximum values at each moment of time, and corresponding to the ratio of the difference and the sum of the command input and output variables of the managed object.

2. In an automatic control system containing a controller connected in series through an actuator to a controlled object, in contrast to the prototype, a digital-to-analog converter serves as an actuator and an analog-to-digital converter is added, connected between the output of the controlled object and the input of the controller, which consists of a master command quantity, series-connected adders, the outputs of which through the divider are connected to the exponentiation block, the output of which th is the controller output, whose inputs are the second inputs of adders serving to output variable managed object.

3. In the system according to claim 2, in contrast to the prototype, the controller consists of a command value master connected to the inputs of the adder and multiplier. The output of the adder is combined with the input of the quadrator, the output of which through the divider is connected to the output of the multiplier, and the output of the divider is connected via the subtraction unit to the output of the controller.

4. In the system of claim 2, in contrast to the prototype, the controller is executed on a programmable logic matrix, including the number of programmable decoders of the binary code of the input variable of the command value and the output variable of the managed object, systematized in the address space of the programmable logic matrix in the number of equivalents of the command quantity sign generator, information inputs of which are used for clocking by variables, and outputs for generating a control signal of the sign generator, which adapt ruetsya on the range by evaluating the actual values of input and output variables to a normalized equivalent of their maximum values at each time point and the corresponding square of the ratio of the difference and the sum of the command input and output variable of the controlled object at the outputs of the logical framework.

The essence of the method and device is illustrated in FIG. 1-8. FIG. 1-5 reflect the structure of the device at the level of generalized and structural, functional and matrix circuits. The dependences of the amplitude-time dynamic characteristics U and the error ε on the type of control action are shown in FIG. 6-7, a qualitative analysis of which is presented in tables 1-3. FIG. Figure 8 shows the dependence of the error ε and the time t of reaching the regime on the coefficient k realized during regulation using the standard criterion.

In the proposed method for automatic control of systems, the output variable ε (E, U) = ε of the actuator is fed to the input of the controlled object, the actual value U of the output variable of the controlled object is measured, which, together with the command value of the input variable E of the controlled object, is used to generate the control signal ε ( U ₂ , E) = ε ₂ . It is fed to the input of the actuator, and use negative feedback on the output variable U of the managed object. To automate regulation in the adaptive range, the output variable U of the controlled object in digital equivalent U _{2 is} fed to the input of the controller unit, the control signal ε (U ₂ , E) = ε _{2 of} which corresponds to the desired properties of the output variable U of the controlled object.

The algorithm for calculating the control signal, in digital ε (U ₂ , E) = ε ₂ and the identical analog ε (U, E) = ε representation, performing the function of an automatic controller (error of the multiplicatively symmetric criterion of the MSC), is estimated by the relative error:

where (X _CG / X _CA ) ² is the ratio of the product of random variables PU _i to their normalized equivalent - max P = X _CA, for i = 1,2, because used n = 2 variables U ₁ = E and U ₂ = U, corresponds to (X _CA ) ² .

Their physical meaning is identical to the square of the geometric mean score:

products of variable signals E and U, as well as the square of the arithmetic mean:

Opening the values of X _SG and X _CA, respectively (2) and (3), we transform (1):

We bring the expression to a common denominator, expand the brackets and combine similar members:

сокращаются в числителе и знаменателе, поэтому получаем относительную погрешность МСК в виде квадрата отношения разности и суммы командной входной Е и выходной переменных U управляемого объекта:The expression [E ² -2EU + U ² ) represents the square of the difference, and $$\frac{\mathrm{one}}{2^2}$$

are reduced in the numerator and denominator, therefore, we obtain the relative error of the MSC in the form of the square of the ratio of the difference and the sum of the command input E and output variables U of the managed object:

The essence of the method is illustrated in FIG. 1-5. FIG. 1 is a generalized block diagram, in which 1 is a controller (K), 2 is an actuator (MI) in the form of a digital-to-analog converter (DAC), 3 is a managed object (UO), 4 is an analog-to-digital converter (ADC).

(4) адаптируется по диапазону за счет оценки фактических величин входной Е и выходной U переменной к нормированному эквиваленту их максимальных max (E,U) величин (3) в каждый момент времени.1. In the generalized block diagram (Fig. 1), the output variable e of the actuator 2 is fed to the input of the managed object 3, the actual value U of the output variable of the managed object is measured, which, together with the command value of the input variable E of the managed object in the code U _{2, is} used to form control signal ε (E, U ₂ ) = ε ₂ . It is fed to the input of the actuator 2, and negative feedback is used on the output variable U of the controlled object 3. To automate regulation in the adaptive range, the output variable U of the controlled object is converted into code U ₂ , and fed to the input of controller 1, the control signal ε of which corresponds to desired properties of the output variable U of the managed entity. The control signal ε is realized by the multiplicatively symmetric criterion (MSC) of the error (4) corresponding to the squared ratio of the difference (EU) and the sum (E + U) of the command input E and output U of the variables of the controlled object 3 and acting as an automatic controller. MSC $$\epsilon ={\left(\frac{E-U}{E+U}\right)}^2$$

(4) adapts over the range by evaluating the actual values of the input E and output U variable to the normalized equivalent of their maximum max (E, U) values (3) at each time point.

2. In FIG. 2 shows a block diagram of an automatic control system comprising a controller 1 connected in series through an actuator 2 to a controlled UOZ object, characterized in that the actuator 3 is a digital-to-analog DAC converter, and an analog-to-digital converter ADC4 connected between the output of the controlled object 3 and the input of controller 1. Controller 1 consists of a command value master (1a), adders (1b) connected in series with it, the outputs of which are through a divider l (1c) are connected with the exponentiation block (1d), the output of which is the output of controller 1, the inputs of which are the second inputs of the adders, which serve for the output variable of the managed object.

On the structural diagram of the system (Fig. 2), the output variable E of the setpoint unit of command value 1a is fed to the input of adders 1b. The actual value of the output variable U (identical to the digital equivalent U ₂ ) of the controlled object 3 is measured, which, together with the value of the input variable E of the controller 1, is fed to the adders 1b. The signals EU and E + U are fed to the divider 1B, and then to the block raising to the power of 1 g, which are used to generate the control signal ε (4). The control signal ε (U ₂ , E) is fed to the input of the DAC actuator 2. The signal from the actuator ε is supplied to the managed object 3. Additionally, negative feedback is used on the output variable of the managed object 3. The control action corresponding to the desired properties of the output variable U of the controlled object 3, implement the multiplicatively symmetric error criterion (1). Block 1 in FIG. 1 corresponds to the square of the ratio of the difference and the sum of the input and output variables of the controlled object U and acts as an automatic controller. MSC adapts to the range by evaluating the actual values of input E and output variable U (2) to the normalized equivalent of their maximum values (3) at each time point. The signal U from the managed object 3 is converted by the ADC 4 into a digital equivalent (signal U ₂ ) and fed to the input of adders 1b.

A specific implementation of the blocks may have the following features (Fig. 1): block 1 is a controller, it is necessary to set the signal E and generate a control signal ε (U ₂ , E) = ε ₂ . Block 2 is an executing mechanism (in the form of a DAC) for converting ε ₂ into an analog signal ε (4). Block 3 is a managed entity. The signal U from the output of the controlled object 3 control is fed to the input of the ADC 4, from which the signal in digital equivalent U _{2 is} fed to the controller unit (1).

3. In FIG. 3 is a functional diagram of the system, characterized in that the controller 1 consists of a command value master (1a) connected to the inputs of the multiplier (1d) and the adder (1b), the output of which is combined with the input of the quadrator (1c), the output of which is through a divider (1g) ) is connected with the output of the multiplier 1d. The output of the divider (1g) is connected via the subtraction unit (1e) to the output of the controller 1.

The input variable E of the master unit 1a is fed to the input of the multiplier 1e and the adder 1b. The signal П = EU from the multiplier 1d is fed to the division unit 1g, and the signal Σ = E + U from the adder 1b is fed to the quadrator 1c and normalized to the power of 2. Then both of these signals are sent to the divider (1g), and their ratio is subtracted from unity in block 1e, i.e. form a control signal (1).

4. The functional diagram is explained by the controller architecture as an indivisible combination of a programmable logic matrix (Fig. 4) and a table (Fig. 5) of error decryption. The controller 1 is made on a programmable logic matrix (PLM, PLM), which includes the number of programmable decoders (DC) of the binary code of the input variable of the command value E and the output variable of the managed object U ₂ , systematized in the address space of the programmable logic matrix into the character generator . Its information inputs d ₀ -d _n serve for clocking with the variables E and U ₂ , and the outputs Y ₀ -Y _m serve for generating a control signal ε (U ₂ , E) = ε ₂ character generator, which adapts to the range by evaluating the actual values input E and output U variables (2) to the normalized equivalent (3) of their maximum values at each moment of time and corresponding to the square of the ratio (4) of the difference and the sum of the command input and output variables of the managed object at the outputs of the logical matrix. The decryption table (Fig. 5) explains the address space of the PLM character generator by the example of the first equivalent command value E (0,1) of the first product decoder (2) to the control signal (4). The first and second columns of the table reflect the output variables U of the managed object, respectively, in binary U ₂ and decimal U ₁₀ code. The last and penultimate columns illustrate the result of decryption of the control signal (4) also in binary ε ₂ and decimal ε ₁₀ code.

The main criteria for evaluating the quality of work of proportional regulation are the error and the time to reach the steady-state value of the dynamic characteristic.

Let us compare the effectiveness of the proposed MSC criterion with the standard criterion, the coefficients of which are manually adjusted:

where E is the steady-state value of the command value of the input variable, and U is the value of the output at a given time. The standard and most common assessment measure is the difference (5) between the steady-state and the current value, which is explained by the simplicity of its calculation. But the reliability and objectivity of this assessment is conditional due to the lack of an optimal equivalent. We normalize criterion (5) to the level of error.

The relative error with the standard criteria is found by the formula:

In FIG. Figure 8 shows the dependences of the error and time to exit to the mode on the coefficient k using the standard criterion (Table 1).

1. Optimization k k Error at t = 0.9 Error time = 0.02 one 0.14 0.89 0.5 0.12 0.85 0.3 0.103 0.81 0.2 0.17 1.7 0.1 0.42 3.8 pre.cr 0 0.23

In the process of manual control (Fig. 8), the best characteristic was selected from the family according to the standard criterion (6) with the optimal control coefficient k = 0.3 with a minimum error ε = 0.103 and the time to reach the mode t = 0.81 s.

The results of computer simulation of the dependence of the amplitude-time dynamic characteristics 1 and 2, corresponding to the multiplicatively symmetric (1,4) and standard (6) criteria, are systematized in FIG. 6. Qualitative analysis of Fig.6 shows an increase in the efficiency of reaching the characteristics mode from standard 1 to precision 2 criteria. For quantitative analysis in FIG. 7, fix the value t = 0.2 and estimate the value of the error at a fixed time (Table 2).

2. Accuracy Types of regulation (time = 0.2) Error: Adaptive MSC 2 0.05 Standard 1 0.65

A quantitative analysis of Table 2 shows a decrease in the control error from 65% for standard 1 to 5% MSC 2 criteria. The error of MSC 2 is 13 times better than standard 1, i.e. precision because an order of magnitude lower.

In FIG. 7 shows the error graphs of the precision criterion MSC 2 and the most optimally adjusted for k = 0.3 (Fig. 8) standard 1 criterion. For the analysis of efficiency, we fix the level of 0.2 error and evaluate the current value of time for efficiency (see table 3).

3. Efficiency Types of regulation (error ε = 0.2) Value t, s Adaptive MSC 2 0.1 Standard 1 0.5

Efficiency in efficiency is calculated from the ratio of the regulation intervals of the standard 1 t ₂ and MSC 2 t ₁ criteria, which allows us to compare how much one criterion is more effective than the other:

As can be seen from FIG. 7, MSC 2 criterion is 5 times more effective than standard 1, i.e. almost an order of magnitude higher.

Let us analyze the effectiveness of the accuracy of the standard 1 criterion ε ₁ relative to the MSC 2 of the criterion ε ₂ , dividing (6) by (4):

We express U in proportion to the command E value U = E / m, then:

From (7) we find:

Suppose that m varies from 1.01 to 1.1, the results of the efficiency η are systematized in Table 4:

4. Efficiency m 1.01 1,02 1,03 1,04 1.05 1.06 1,07 1,08 1.09 1,1 η 400 200 133 one hundred 80.1 66.7 57.2 50.1 44.5 40.1

From table 4 it is seen that ε _{1 is} always η times greater than ε ₂ , therefore, the proposed MSC 2 is 2 orders of magnitude more effective than standard 1. In addition, (7) shows that m can vary in the range from 1 to 0 and is physically a control coefficient k, i.e. η = k (table 5):

5. The control coefficient m 0.9 0.8 0.7 0.6 0.5 0.4 0, (3) 0.2 0.1 0.01 η 40 twenty 13.3 10.7 9 8.2 8 9 13,4 103

From Table 5 it follows that the control coefficient is not a constant, but a function with an optimum at m = 0.3 (3), which allows us to conclude that it is adaptive in automating the regulation process to the desired optimal normalized equivalent.

Thus, the formation of a control signal by a program-controlled standardized measure of the MSC error, in contrast to the known solutions, doubles the efficiency in accuracy and the order of magnitude of the efficiency of automatic control by evaluating the actual values of the input and output variables to the normalized equivalent of their maximum values. The normalized equivalent for follow-up feedback automatically optimizes the parameters of the dynamic characteristics of the system in the adaptive range, this eliminates manual control by the operator and increases the metrological efficiency by an order of magnitude.

Claims (4)

1. The method of automatic control of systems, in which the output variable of the actuator is fed to the input of the managed object, measure the actual value of the output variable of the managed object, which, together with the command value of the input variable of the managed object, is used to generate a control signal, which is fed to the input of the actuator due to the use of negative feedback on the output variable of the managed object, characterized in that the output variable In the digital equivalent, the supplied object is fed to the input of the controller unit, the control signal of which corresponds to the desired properties of the output variable of the controlled object, and it is implemented by the multiplicatively symmetric error criterion, which acts as an automatic controller that adapts to the range by evaluating the actual values of the input and output variables to the normalized equivalent of their maximum values at each moment of time, and the corresponding squared relations of the difference and the sum of the command input single and output variables of the managed object. 2. An automatic control system comprising a controller connected in series through an actuator to a controlled object, characterized in that the digital-to-analog converter is used as an actuator and an analog-to-digital converter is added, connected between the output of the controlled object and the input of the controller, which consists of a command unit of adders connected in series with it, the outputs of which through the divider are connected to the exponentiation block, the output of which is the controller output, the inputs of which are the second inputs of the adders, which serve for the output variable of the managed object. 3. The system according to claim 2, characterized in that the controller consists of a command value commander connected to the inputs of the multiplier and the adder, the output of which is combined with the input of the quadrator, the output of which is connected through the divider to the output of the multiplier, and the output of the divider is connected through the subtraction unit with controller output. 4. The system according to claim 2, characterized in that the controller is executed on a programmable logic matrix, including the number of programmable decoders of the binary code of the input variable of the command value and the output variable of the managed object, systematized in the address space of the programmable logic matrix into the character generator, according to the number of command-value equivalents information inputs of which are used for clocking by variables, and outputs are used to form a control signal of the character generator, which is adapted etsya on the range by evaluating the actual values of input and output variables to a normalized equivalent of their maximum values at each time point and the corresponding square of the ratio of the difference and the sum of the command input and output variable of the controlled object at the outputs of the logical framework.

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