RU2661180C1 - Method of searching for faulty unit in continuous dynamic system based on change of position of input signal - Google Patents

Abstract

FIELD: control systems; computer engineering.

SUBSTANCE: invention relates to the diagnosis of automatic control. In the method for searching for a faulty block in a continuous dynamic system, based on the change in the position of the input signal, the number of blocks included in the system is recorded, control time is determined, integral signal conversion parameter is determined. Signs of deviations of integral estimates of the output signals of the model and the controlled system are also determined. Elements of the deviation marks vector of integral estimates of the output signals of the model are compared in pairs. Binary diagnostic features are calculated. Faulty structural block with a defect is determined using the unit value of the binary diagnostic feature.

EFFECT: hardware and computing costs are reduced.

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Description

The invention relates to the field of monitoring and diagnosing automatic control systems and their elements.

There is a method of searching for a faulty block in a continuous dynamic system (Method for finding a faulty block in a continuous dynamic system: Pat. 2461861 Russian Federation: IPC ⁷ G05B 23/02 (2006.01) / Shalobanov SS - No. 2011 140376/08; Decl. 04.10 .2011; publ. 09/20/2012, Bull. No. 26).

The disadvantage of this method is that it uses the calculation of the signs of the transmission of signals from the outputs of the blocks to the control points.

The closest technical solution (prototype) is a method for finding a faulty block in a continuous dynamic system based on a change in the position of the input signal (Method for finding a faulty block in a continuous dynamic system based on a change in the position of an input signal: Pat. 2528135 Russian Federation: IPC ⁷ G05B 23 / 02 (2006.01) / Shalobanov S.S. - No. 2013144231/08; application. 01.10.2013; publ. September 10, 2014, Bull. No. 25).

The disadvantage of this method is that it involves the use of complex diagnostic signs of a defect in the structural block of the system.

The technical problem to which this invention is directed is to reduce the hardware and computing costs associated with the implementation of the calculation of diagnostic signs of a defect.

, путем подачи на первые входы k блоков перемножения сигналов системы управления, на вторые входы блоков перемножения подают экспоненциальный сигнал e ^-αt, выходные сигналы k блоков перемножения подают на входы k блоков интегрирования, интегрирование завершают в момент времени Т_к, полученные в результате интегрирования оценки выходных сигналов F _{j ном} (α), j=1, …, k регистрируют, фиксируют число m блоков системы, определяют интегральные оценки выходных сигналов модели для каждой из k контрольных точек и каждой из m позиций входного сигнала, полученные в результате смены позиции входного сигнала после каждого из m блоков, для чего поочередно для каждого блока динамической системы перемещают место подачи входного сигнала на выход каждого блока, подают через сумматор входной сигнал и находят интегральные оценки выходных сигналов системы для параметра α и входного сигнала x(t), полученные в результате интегрирования оценки выходных сигналов для каждой из k контрольных точек и каждой из m моделей с различной (зафиксированной на выходах разных блоков) позицией входного сигнала Y _ji (α), j = 1, …, k; i = 1, …, m регистрируют, определяют деформации интегральных оценок выходных сигналов модели, полученные в результате перемещения позиции входного сигнала на позицию после каждого из соответствующих блоков ΔY _ji (α)=Y _ji (α)-F _{j ном} (α), j=1, …, k; i=1, …, m, определяют знаки отклонений интегральных оценок выходных сигналов модели, полученные в результате перемещения позиции входного сигнала на позицию после каждого из соответствующих блоков singn(ΔY _ji (α)), j=1, …, k; i=1, …, m, замещают систему с номинальными характеристиками контролируемой, на вход системы подают аналогичный тестовый сигнал x(t), определяют интегральные оценки выходных сигналов контролируемой системы для k контрольных точек F _j (α), j=1, …, k для параметра интегрирования α, определяют отклонения интегральных оценок выходных сигналов контролируемой системы для к контрольных точек от номинальных значений ΔF _j (α)=F _j (α)-F _{j ном} (α), j=1, …, k, определяют знаки отклонений интегральных оценок выходных сигналов контролируемой системы для k контрольных точек от номинальных значений sign(ΔF _j (α)), j = 1, …, k.The task is achieved by pre-registering the reaction of a known-good system ƒ _{j nom} (t), j = 1, ..., k on the interval t∈ [0, T _K ] at k control points, and determine the integral estimates of the output signals F _{j nom} (α), j = 1, ..., k of the system, which at the moment of supplying input to the input systems with nominal characteristics simultaneously begin integration control system signals in each of the control points k with weights e ^-αt, wherein

By supplying to the first inputs k multiplication control system signal blocks, the second inputs of multiplying the signal blocks supplied exponential e ^-αt, output signals k multiplying unit is supplied to the inputs k of integration blocks, integration is completed at time T _k obtained by integrating the evaluation output signals _SG F _j (α), j = 1, ..., k is recorded, the number m is fixed system blocks define integral estimates signals output pattern for each of the control points k and m each of the input positions, floor chennye resulting change in position of the input signal after each of the m blocks, which in turn for each dynamic system block is moved place input signal supplied to the output of each unit is fed through the adder input signal and are integrated evaluation system outputs to the parameter α and the input signal x (t) obtained by integrating the estimates of the output signals for each of k control points and each of m models with different (fixed at the outputs of different blocks) input signal position Y _ji (α), j = 1, ..., k ; i = 1, ..., m are recorded, the deformations of the integral estimates of the model output signals obtained by moving the position of the input signal to the position after each of the corresponding blocks Δ Y _ji (α) = Y _ji (α) - F _{j nom} (α) are determined , j = 1, ..., k ; i = 1, ..., m , determine the signs of deviations of the integrated estimates of the output signals of the model obtained by moving the position of the input signal to the position after each of the corresponding blocks singn (Δ Y _ji (α)), j = 1, ..., k ; i = 1, ..., m , replace the system with the nominal characteristics of the controlled one, a similar test signal x (t) is fed to the input of the system, determine the integrated estimates of the output signals of the controlled system for k control points F _j (α), j = 1, ..., k for the integration parameter α, the deviations of the integral estimates of the output signals of the controlled system for k control points from the nominal values Δ F _j (α) = F _j (α) - F _{j nom} (α), j = 1, ..., k are determined, determine signs of deviations of the integrated estimates of the output signals of the controlled system for k control points from the nominal values of sign (Δ F _j (α)), j = 1, ..., k .

Then pairwise comparison operation produce vector elements integral estimates signs deviations model output signals resulting from movement of the input position to position after each of the respective blocks i th block _{sign (Δ Y ji (α)} ), j = 1, ..., k ; i = 1, ..., m and the vector of signs of deviations of the integral estimates sign (Δ F _j (α)), j = 1, ..., k, according to the formula:

Since the operation ≡ is an equivalence operation, expression (1) takes the value 1 only if all elements of the vectors sign (Δ Y _ji (α)), j = 1, ..., k and sign (Δ F _j (α) ), j = 1, ..., k for each control point are pairwise equal.

Then produce pairwise comparison operation element inversion vector topological relations i th block _{inv (sign (Δ Y ji (} α)), j = 1, ..., k; i = 1, ..., m, and the vector deviation marks integral sign changes ( Δ F _j (α)), j = 1, ..., k , by the formula:

Since the operation ≡ is an equivalence operation, expression (2) takes the value 1 only if all elements of the vectors inv (sign (Δ Y _ji (α))), j = 1, ..., k . and sign (Δ F _j (α)), j = 1, ..., k , are equal in pairs for each control point.

Then produce the calculation of binary diagnostic features from the ratio:

The first term of formula (3) takes the value 1 if the signs of the deviations of the integral estimates of the output signals of the controlled system from the nominal values coincide with the elements of the vector of signs of the deviations of the integral estimates of the output signals of the model obtained by moving the position of the input signal, the second term of the formula (3) takes the value 1, if the signs of deviations of the integrated estimates of the output signals of the controlled system from the nominal values coincide with the inverted elements of the vector of signs of deviations th integral estimates of the output signals of the model obtained by moving the position of the input signal. The inversion of the vector of signs of deviations of the integral estimates of the output signals of the model obtained by moving the position of the input signal to the position after each of the corresponding blocks takes into account the possibility of a defect in the same block both with a plus sign (for example, an increase in the value of a block parameter) and with a minus sign (e.g. decreasing the value of a block parameter).

The unit value of the binary diagnostic feature determines the structural unit with a defect.

Thus, the proposed method for finding a faulty unit is reduced to performing the following operations:

1. As a dynamic system, consider a system consisting of arbitrarily connected m dynamic blocks.

2. Pre-determine the monitoring time T _To ≥ T _PP , where T _PP - the transition process of the system. Transient time is estimated for the nominal values of the parameters of the dynamic system.

.3. Determine the parameter of the integral signal conversion from the ratio

.

4. Fix the number of control points k .

5. Preliminarily determine the sign vectors of the deviations of the integrated estimates of the output signals of the model sing (Δ Y _i (α)), i = 1, ..., m , obtained by moving the position of the input signal to the position after the i- th block of each of m blocks for nominal the values of the parameters of the transfer functions of the blocks and the parameter α defined above, for which paragraphs 6-10 are performed.

6. A test signal x (t) (unit step, linearly increasing, rectangular pulse, etc.) is supplied to the input of a control system with nominal characteristics. The proposed method does not provide fundamental restrictions on the type of input test exposure.

, для чего сигналы системы управления подают на первые входы k блоков перемножения, на вторые входы блоков перемножения подают экспоненциальный сигнал e ^-αt, выходные сигналы к блоков перемножения подают на входы k блоков интегрирования, интегрирование завершают в момент времени Т _κ , полученные в результате интегрирования оценки выходных сигналов F _{j ном} (α), j=1, …, k регистрируют.7. The reaction of the system ƒ _{j nom} (t), j = 1, ..., k , on the interval t∈ [0, T _K ] at k control points is recorded and the integral estimates of the output signals F _{j nom} (α), j = 1 are determined , ..., k , systems. To do this, at the time of supplying a test signal to the input of the control system with nominal characteristics, the integration of the output signals of the control system at each of k control points with weights e ^{-αt starts simultaneously}

For which the control system signals are supplied to first inputs of multiplying the k blocks, the second inputs of multiplying the signal blocks supplied exponential e ^-αt, outputs to the multiplying unit is supplied to the inputs k of integration blocks, integration is completed at time T _κ, obtained by integrating the estimates of the output signals F _{j nom} (α), j = 1, ..., k are recorded.

8. Integral estimates of the model output signals for each of k control points are determined, obtained as a result of moving the position of the input signal to the position after each of m blocks, for which, for each block of the dynamic system, the position of the input signal is transferred to the output of the block, fed through the input adder signal and perform paragraphs 6 and 7 for the same input signal x (t) . Estimates of the output signals obtained as a result of integration for each of k control points and each of m models with a displaced position of the input signal Y _ji (α), j = 1, ..., k ; i = 1, ..., m , register.

9. Determine the deformations of the integral estimates of the output signals of the model obtained by moving the position of the input signal from the input to the position after each of the corresponding blocks Δ Y _ji (α) = Y _ji (α) - F _{j nom} (α), j = 1, ..., k ; i = 1, ..., m .

10. Determine the signs of deviations of the integrated estimates of the model output signals obtained by moving the position of the input signal to the position after each of the corresponding blocks sign (Δ Y _ji (α)), j = 1, ..., k ; i = 1, ..., m .

11. Replace the system with the rated characteristics controlled. A similar test signal x (t) is supplied to the system input.

12. Determine the integral estimates of the output signals of the controlled system for k control points F _j (α), j = 1, ..., k, performing the operations described in paragraphs 6 and 7 with respect to the controlled system.

13. The deviations of the integrated estimates of the output signals of the controlled system for k control points from the nominal values Δ F _j (α) = F _j (α) - F _{j nom} (α), j = 1, ..., k are determined .

14. Determine the signs of deviations of the integrated estimates of the output signals of the controlled system for k control points from the nominal values of sign (Δ F _j (α)), j = 1, ..., k .

15. Perform the operation of pairwise comparing the elements of the vector of the signs of the deviations of the integral estimates of the output signals of the model, obtained by changing the position of the input signal of the i- th block sign (Δ Y _ji (α)), j = 1, ..., k ; i = 1, ..., m , and the vector of signs of deviations of the integral estimates sign (Δ F _j (α)), j = 1, ..., k , according to the formula:

16. The operation of pairwise comparing the elements of the inversion of the vector of signs of deviations of the integral estimates of the model output signals obtained as a result of changing the position of the input signal of the i- th block inv (sign (Δ Y _ji (α))), j = 1, ..., k ; i = 1, ..., m , and the vector of signs of deviations of the integral estimates sign (Δ F _j (α)), j = 1, ..., k , according to the formula:

17. Perform the calculation of binary diagnostic features from the ratio:

18. The unit value of the binary diagnostic feature determines the structural unit with a defect.

Consider the implementation of the proposed method for finding a defect for a system whose structural diagram is shown in the figure (see. Fig. The structural diagram of the diagnostic object).

Transfer functions of blocks:

;

;

,

;

;

,

nominal values of the parameters: k ₁ = 1; T ₁ = 5 s; k ₂ = 1; T ₂ = 1 s; k ₃ = 1; T ₃ = 5 s.

When searching for a single defect in the form of a deviation of the time constant T ₁ = 4s (defect No. 1) in the first link by supplying a step test input signal of unit amplitude and integral signal estimates for the parameter α = 0.5 and T _κ = 10 s , the values of binary diagnostic signs of presence defect according to the formula (3) when using three control points located at the outputs of the blocks. The defect calculated by the formula (3) gives the following values of binary diagnostic features: J ₁ = 1; J ₂ = 0; J ₃ = 0 .

Modeling of the defect search processes in the second and third blocks for a given diagnostic object, with the same integration parameter α and with a single step input signal, gives the following values of binary pointers:

If there is a defect in block No. 2 (in the form of a decrease in the parameter T ₂ by 20%, defect No. 2): J ₁ = 0; J ₂ = 1; J ₃ = 0 .

If there is a defect in block No. 3 (in the form of a decrease in the parameter T ₃ by 20%, defect No. 3): J ₁ = 0; J ₂ = 0; J ₃ = 1 .

The single value of the binary diagnostic feature in all cases correctly determines the defective block.

Claims (9)

A method for finding a faulty block in a continuous dynamic system based on a change in the position of the input signal, based on the fact that the number of blocks m that are part of the system is fixed, the monitoring time T _K ≥T _{PP is} determined, where T _PP is the system transition time, the parameter is determined integral signal conversion from the ratio

, use a test signal on the interval t∈ [0, T _K ], use the integral signal estimates obtained for real values of the parameter α as the dynamic characteristics of the system, fix the number k of control points of the system, record the reaction of the diagnostic object and the reaction of a known-good system ƒ _{j nom} (t), j = 1, ..., k on the interval t∈ [0, T _K ] at k control points, determine the integral estimates of the output signals F _{j nom} (α), j = 1, ..., k of a working system, for which at the time of the test signal at the input of the system with nominal characteristics simultaneously begin integration of the output signals of the control system in each of k control points with weights e ^-αt , where

by supplying the output signals of the control system to the first inputs k of the multiplying units, the exponential signal e ^{-αt is} supplied to the second inputs of the multiplying units, the output signals of the multiplying units are fed to the inputs of the integration blocks k, the integration is completed at time T _to , obtained as a result of integration of the estimate output signals F _{j nom} (α), j = 1, ..., k, register, replace the system with the nominal characteristics of the controlled, the input of the system serves the same test signal x (t), determine the integral output estimates data of the controlled system for k control points F _j (α), j = 1, ..., k for parameter α, the deviations of the integrated estimates of the output signals of the controlled system for k control points from the nominal values ΔF _j (α) = F _j (α ) -F _{j nom} (α), j = 1, ..., k, determine the integral estimates of the model output signals for each of the k control points obtained by changing the position of the input signal to the position after each of the m blocks, for which each unit of the dynamic system move the position of the input signal at position n after each block under consideration, the input signal x (t) is fed through the adder there and the integral estimates of the system output signals for the parameter α and the input signal x (t) are obtained by integrating the estimates of the output signals for each of k control points and each of m models with a shifted input signal position Y _ji (α), j = 1, ..., k; i = 1, ..., m register, determine the deformation of the integral estimates of the output signals of the model obtained by moving the position of the input signal to the position after each of the corresponding blocks ΔY _ji (α) = Y _ji (α) -F _{j nom} (α), j = 1, ..., k; i = 1, ..., m, characterized in that the signs of deviations of the integrated estimates of the output signals of the model are determined, obtained by moving the position of the input signal to the position after each of the corresponding blocks: sign (ΔY _ji (α)), j = 1, ..., k; i = 1, ..., m, determine the signs of deviations of the integrated estimates of the output signals of the controlled system for k control points from the nominal values of sign (ΔF _j (α)), j = 1, ..., k, perform the operation of pairwise comparing the elements of the vector of signs of the integral deviations of the integral estimates of the model output signals obtained as a result of a change in the position of the input signal of the ith block sign (ΔY _ji (α)), j = 1, ..., k; i = 1, ..., m, and the vector of signs of deviations of the integral estimates sign (ΔF _j (α)), j = 1, ..., k, according to the formula:

, i = 1, ..., m, perform the operation of pairwise comparing the elements of the inversion of the vector of signs of deviations of the integral estimates of the output signals of the model obtained by changing the position of the input signal of the i-th block inv (sign (ΔY _ji (α))), j = 1, ..., k; i = 1, ... m, and the vector of signs of deviations of the integral estimates sign (ΔF _j (α)), j = 1, ..., k according to the formula:

, i = 1, ..., m, calculate binary diagnostic features from the ratio:

, i = 1, ..., m, the unit value of the binary diagnostic feature determines the structural unit with a defect.

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