CN111090945B - Actuator and sensor fault estimation design method for switching system - Google Patents
Actuator and sensor fault estimation design method for switching system Download PDFInfo
- Publication number
- CN111090945B CN111090945B CN201911326838.9A CN201911326838A CN111090945B CN 111090945 B CN111090945 B CN 111090945B CN 201911326838 A CN201911326838 A CN 201911326838A CN 111090945 B CN111090945 B CN 111090945B
- Authority
- CN
- China
- Prior art keywords
- observer
- fault
- actuator
- fault estimation
- substances
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F17/00—Digital computing or data processing equipment or methods, specially adapted for specific functions
- G06F17/10—Complex mathematical operations
- G06F17/11—Complex mathematical operations for solving equations, e.g. nonlinear equations, general mathematical optimization problems
- G06F17/13—Differential equations
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F17/00—Digital computing or data processing equipment or methods, specially adapted for specific functions
- G06F17/10—Complex mathematical operations
- G06F17/16—Matrix or vector computation, e.g. matrix-matrix or matrix-vector multiplication, matrix factorization
Abstract
The invention discloses a method for switchingThe fault estimation design method for the actuator and the sensor of the system comprises the following steps: 1) establishing a continuous time switching system model to complete preparation work; 2) designing a fault estimation observer, and designing observer parameters to obtain a gain matrix of the observer; 3) accurately estimating the state of the system on lineActuator failure fa(t) sensor failure fs(t) and a measurement disturbance ω (t). Compared with the prior art, the fault diagnosis observer based on the adaptive observer meets the robustness of the fault diagnosis system to external disturbance, so that the error system is stable and meets the requirement of H∞And the performance index realizes accurate online estimation of faults of an actuator and a sensor of the system.
Description
Technical Field
The present invention relates to a design method for an adaptive fault estimation observer for switching systems with actuator and sensor faults.
Background
With the rapid development of science and technology, engineering systems become more and more complex, which makes the requirements for the safety and reliability of the systems higher and higher. In the actual production process, the system is inevitably failed, which can cause the performance reduction, the stability deterioration and the system breakdown of the system, and even bring catastrophic property and personnel loss. An effective method, namely a fault diagnosis technology, is provided for solving the problem of faults in industrial production, and is widely applied. The fault diagnosis technology comprises three parts of fault detection, fault isolation and fault estimation. The fault detection is the primary work of the fault diagnosis technology, namely, whether a system has a fault or not is quickly judged. And determining the fault, and then performing the next fault estimation and other work. Compared with the fault detection technology, the fault estimation technology can obtain more fault information, such as: the form of the failure. At present, observer-based fault diagnosis methods are more popular, such as adaptive observers, sliding mode observers, proportional-integral observers (PIO), Unknown Input Observers (UIO), and the like. Where the output and variance of a proportional-integral observer (PIO) are considered known and can be used, but if there is a measurement disturbance or sensor fault in the system, a conventional observer cannot be applied directly, which may be amplified by the observer gain. Therefore, various observer design methods are proposed, wherein the generalized observer design method is widely applied, including the original system state and the sensor fault. From the above results, it can be seen that the system model plays an important role, and the fault estimation observer can be designed according to the model information. However, in practical applications, it is very difficult to know all the information of the dynamic system, and measurement disturbance may affect the estimation result. Further, it is noted that when the actuator failure is slowly time varying, the PIO can achieve good estimation performance. Conversely, if the fault changes frequently, the estimated performance may be affected by the fault differential.
In an actual engineering system, an electric power system, a chemical system, a mechanical system, an aerospace system and the like can be modeled into a switching system in a mathematical analysis mode, and control theory research based on a model method becomes one of important research directions of a control theory. With a very practical modeling form, the fault diagnosis research of the switching system has become one of the mainstream research directions in the field of control theory, and a great deal of researchers are attracted to research on the fault diagnosis research in recent years. The switching system is a kind of hybrid system, and includes a plurality of subsystems (continuous subsystems or discrete subsystems) and a rule for coordinating switching between the subsystems. The switching signal can be classified into an arbitrary switching and a constrained switching according to the switching characteristics. The average residence time (ADT) technique is a limited switching signal that requires the average running time of the subsystems to be greater than a constant value for a limited time, with less conservation than the classical algorithms. Therefore, the ADT technology is widely used in fault diagnosis and fault-tolerant control.
The present document mainly studies the problem of fault estimation for a class of continuous-time linear switching systems. Firstly, based on average residence time (ADT) and switching Lyapunov function, a fault estimation observer of an augmented switching system is designed, so that an error system is gradually stabilized. On the basis, the fault of the system is accurately estimated. Finally, the estimation effect of the designed observer is illustrated by calculation.
Disclosure of Invention
The purpose of the invention is as follows: aiming at the problems in the prior art, the invention provides a fault estimation design method for an actuator and a sensor of a switching system, which can accurately estimate the fault form of the system on line, so that an error system is gradually stable, the elimination of external disturbance by a fault diagnosis system is realized, and the on-line fault estimation of the system is satisfied.
The technical scheme is as follows: the invention provides a fault estimation design method for an actuator and a sensor of a switching system, which comprises the following steps:
step 1: constructing a continuous time switching system model, and completing related preparation work, wherein the related preparation work comprises introducing a replacement variable and reconstructing an augmentation system;
the continuous time switching system model is as follows:
wherein, x (t) ∈ Rn,d(t)∈RdRespectively representing a state vector, a control input vector, a measurable output vector and an external disturbance vector of the system; the system has actuator fault, sensor fault and measurement disturbance caused byIs represented by RnRepresenting a set of n-dimensional real vectors, Ai,Bi,Ci,Di,Fi,Wi,GiRepresenting a known constant matrix of appropriate dimensions; sigmai(t) is a switching signal, which is required to satisfy:
step 2: aiming at the continuous time switching system model in the step 1, designing a fault estimation observer, and designing observer parameters to obtain a gain matrix of the observer;
the fault estimation observer is designed as follows:
wherein the content of the first and second substances,andwhich represents the state of the observer,respectively represent z (t), x (t),fa(t) and y (t) is an adjustable parameter, and the gain of the fault estimation observer is
And step 3: estimating the state of the system on lineActuator failure fa(t) sensor failure fs(t) and a measurement disturbance ω (t). Further, the process of introducing the replacement variable and reconstructing the augmented system in step 1 is as follows:
2.1) introducing the variable η (t):
from the output equation (4), we get:
therefore, the temperature of the molten metal is controlled,
wherein the content of the first and second substances,because of the fact thatIs of full rank, with its left inverse presentTo express, then can knowThus existSo thatThe following can be obtained:
2.3) the output y (t) is measurable, andis difficult to measure, in the above formula (7), the right side of the equal sign containsTo this end, a new variable z (t) is introduced:
further, the system state error and parameters of the fault estimation observer in the step 2 are designed as follows:
3.1) systematic state error:
then there is e (t) ═ ez(t), it is possible to obtain:
the following can be obtained:
wherein the content of the first and second substances,
3.3) observer parameter design:
case 1: when in useThe error system equation (15) is asymptotically stable and satisfies H∞The performance index γ, that is:
wherein the content of the first and second substances,the ADT constraint is satisfied for any switching signal:
the error system (15) is stable and satisfies H∞The performance index γ. By solving the linear matrix inequality (17), the gain matrix in the fault estimation observer in 4.1) can be obtained as:
further, the state of the system is estimated online in step 3Actuator failure fa(t) sensor failure fs(t) and a measured disturbance ω (t), which can be done as follows:
has the advantages that:
1. based on the adaptive observer technique, a new adaptive dynamic proportional-integral observer (PIO) is designed to estimate system states, actuator and sensor faults, and measure disturbances. In a dynamic proportional-integral observer (PIO), the output and output differential information of an original system are used, which is different from the existing method, the fault form of the system can be accurately estimated on line, an error system is enabled to be gradually stable, the elimination of external disturbance by a fault diagnosis system is realized, and the online fault estimation of the system is satisfied.
2. The designed fault estimation observer satisfies H∞The performance is gradually stable;
3. the fault estimation design method provided by the invention has general adaptability.
Drawings
FIG. 1: a flow diagram of the present invention;
FIG. 2: switching signal diagram sigma in the inventioni(t);
FIG. 3: external disturbances in the system: white noise d (t);
Detailed Description
The present invention will be described in detail with reference to the accompanying drawings.
The invention provides a design method of a self-adaptive fault estimation observer for a switching system with faults of an actuator and a sensor by taking a continuous time switching system model as an implementation object and aiming at faults occurring in the system.
And (4) note marking: p involved in the algorithm of the inventionT,P-Respectively representing the transpose of the matrix P and the inverse of the matrix, P > 0(P < 0) indicating that the P matrix is a positive (negative) definite matrix, RnRepresenting a set of n-dimensional real vectors, I and 0 representing identity matrices and 0 matrices with appropriate dimensions, where x represents the symmetric terms in the symmetric matrix.
In the present invention, some of the quotations and related definitions are used, and a brief description is given first:
1) definition 1: for arbitrary switching signal sigmai(t) and an arbitrary time t2>t1Is greater than 0, orderIs shown in the time period (t)1,t2) Inner number of handovers, for a given N0≥0,τa> 0 if the following holds:
then constant τaReferred to as average residence time, N0Called buffeting limit value.
2) Note 1: the switching signal involved in the invention is a slow switching signal, and has a residence time longer than the classical residence timeThe switching signal is less conservative and more general, and for simplicity, the invention makes the buffeting boundary N0=0。
3) Introduction 1: considering continuous time switching system modelLet α > 0, μ > 1 all be given constantsFunction(s)And two typesFunction k1,k2Such that:
and isVi(x(t))≤μVi(x (t)), then the switching systemADT constraints are satisfied for any switching signal:the system is stable.
4) Assume that 1: matrix Wi,GiIs of full rank.
The fault estimation method comprises the following steps:
step 1: and establishing a continuous time switching system model and carrying out preparation work.
The continuous time switching system model is as follows:
wherein, x (t) ∈ Rn,d(t)∈RdRespectively representing a state vector, a control input vector, a measurable output vector and an external disturbance vector of the system. The actuator fault, sensor fault and measurement disturbance of the system can be respectively composed ofIs represented by RnRepresenting a set of n-dimensional real vectors, Ai,Bi,Ci,Di,Fi,Wi,GiRepresenting a known constant matrix of appropriate dimensions; sigmai(t) is a switching signal, which is required to satisfy:
the parameters of each constant real matrix of the system are expressed as follows:
for simplicity, we first make some variable substitutions, the process is as follows:
1) introducing variable η (t):
at this time, from the output equation (4), we find:
thus:
because of the fact thatIs full rank, so its left inverse existsTo express, then can knowThus existSo thatBased on the above analysis it can be found that:
3) in general, we know that the output y (t) is measurable, andis difficult to measure, in the above formula (7), the right side of the equal sign containsTo avoid this problem, we introduce a new variable z (t):
step 2: the following fault estimation observer is designed, and the specific content is as follows:
1) based on the transformation of the above equation (9), the following fault observer is designed, and the process is as follows:
in the formula (10), the compound represented by the formula (10),andwhich represents the state of the observer,respectively represent z (t), x (t),fa(t) and y (t), are adjustable parameters,representing the observer gain.
2) Error of system state:
we have e (t) ═ ez(t), then, it can be known that:
then, it can be known that:
wherein the content of the first and second substances,
4) the observer parameter design process is carried out as follows:
theorem: for a given parameter γ > 0, μ > 1, α > 0:
case 1: when in useThe error system (15) is asymptotically stable and satisfies H∞The performance index γ, that is:
wherein the content of the first and second substances,the ADT constraint is satisfied for any switching signal:
the error system (15) is stable and satisfies H∞The performance index γ. By solving the linear matrix inequality (17), the gain matrix in the fault estimation observer in step 4.1) can be obtained as:
the proof process of theorem is as follows: for a given parameter γ > 0, μ > 1, α > 0:
(1) when in useThen, we build the stability of the stand (15): the following switching Lyapunov function is defined:
wherein, Pi> 0, one can get:
we define:
the formula (16) is also satisfied by the following formula:
in the formula (22), the reaction mixture is,therefore, if (17) is true, φ < 0 can be obtained. Given below is H∞Proof of performance index, for the system (15), defines:
then there are:
the formula (22) also represents:
And step 3: for accurately estimating the state of the system on lineActuator failure fa(t) sensor failure fs(t) and measuring the disturbance ω (t), and performing the following work by a specific method:
the alternative known sensor fault estimation and measurement disturbance estimation from the variables described above can be represented by the following equations:
in summary, the algorithm of the present invention comprises the following steps:
the first step is as follows: an augmentation system (7) is constructed.
The second step is that: calculating the gain matrix K of the observer according to (17)1i,K2iAnd an unknown matrix Pi,Qi。
The third step: based on the fault estimation observer (equation (10)), a state estimate can be obtainedAnd actuator fault estimation
The fourth step: since the state estimate has already been obtained in the third step, we can obtain a sensor fault estimate by (25)And measurement disturbance estimation
When α is equal to 0.5, mu is equal to 1.01, and gamma is equal to 0.2, the product can be obtainedBy using a linear matrix inequality tool in MATLAB, a gain matrix K can be obtained1i,K2i:
K21=1.0*e8[-1.3358 0.0474],K22=1.0*e7[-1.8078 8.4465],
K23=1.0*e8[-2.0972 1.5217]
Assuming that the switching system actuator fails, the failure model is as follows:
assuming a ramp signal when a sensor of the system fails, the failure model is as follows:
we consider the measured disturbance as a time-varying signal, modeled as follows:
for the simulation, the switching signal of the system is shown in FIG. 3, FIG. 4 is the external disturbance white noise and the actuator fault signal f in the systema(t) and estimation thereofAs shown in fig. 4, sensor failure signal fs(t) and estimation thereofFIG. 6 shows the measured disturbance signal ω (t) and its estimation, as shown in FIG. 5
From the simulation result, when the system has a fault, the fault noble observer designed by the invention can estimate the fault of the actuator, the fault of the sensor and the measurement disturbance on line, and has practical value.
The above embodiments are merely illustrative of the technical concepts and features of the present invention, and the purpose of the embodiments is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.
Claims (4)
1. A design method for fault estimation of actuators and sensors of a switching system, comprising the steps of:
step 1: constructing a continuous time switching system model, and completing related preparation work, wherein the related preparation work comprises introducing a replacement variable and reconstructing an augmentation system;
the continuous time switching system model is as follows:
wherein, x (t) ∈ Rn,d(t)∈RdRespectively representing a state vector, a control input vector, a measurable output vector and an external disturbance vector of the system; actuator failure, sensor failure of a systemAnd measuring the disturbance respectively byIs represented by RnRepresenting a set of n-dimensional real vectors, Ai,Bi,Ci,Di,Fi,Wi,GiRepresenting a known constant matrix of appropriate dimensions; sigmai(t) is a switching signal, which is required to satisfy: sigmai(t):[0,∞)→{0,1},
Step 2: aiming at the continuous time switching system model in the step 1, designing a fault estimation observer, and designing observer parameters to obtain a gain matrix of the observer;
the fault estimation observer is designed as follows:
wherein the content of the first and second substances,andwhich represents the state of the observer,
respectively represent z (t), x (t),fa(t) and y (t) is an adjustable parameter, and the gain of the fault estimation observer is
And step 3: on-lineEstimating the state x (t) of the system, the actuator fault fa(t) sensor failure fs(t) and a measurement disturbance ω (t).
2. The actuator and sensor fault estimation design method for switching system as claimed in claim 1, characterized in that the process of introducing replacement variables and reconstructing the augmented system in step 1 is as follows:
2.1) introducing the variable η (t):
from the output equation (4), we get:
therefore, the temperature of the molten metal is controlled,
because of the fact thatIs of full rank, with its left inverse presentTo express, then can knowThus existSo thatThe following can be obtained:
2.3) the output y (t) is measurable, andis difficult to measure, in the above formula (7), the right side of the equal sign containsTo this end, a new variable z (t) is introduced:
3. the actuator and sensor fault estimation design method for switching systems of claim 2, wherein the system state errors and parameters of the step 2 fault estimation observer are designed as follows:
3.1) systematic state error:
then there is e (t) ═ ez(t), it is possible to obtain:
the following can be obtained:
wherein the content of the first and second substances,
3.3) observer parameter design:
case 1: when in useThe error system equation (15) is asymptotically stable and satisfies H∞The performance index γ, that is:
wherein the content of the first and second substances,the ADT constraint is satisfied for any switching signal:
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201911326838.9A CN111090945B (en) | 2019-12-20 | 2019-12-20 | Actuator and sensor fault estimation design method for switching system |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201911326838.9A CN111090945B (en) | 2019-12-20 | 2019-12-20 | Actuator and sensor fault estimation design method for switching system |
Publications (2)
Publication Number | Publication Date |
---|---|
CN111090945A CN111090945A (en) | 2020-05-01 |
CN111090945B true CN111090945B (en) | 2020-08-25 |
Family
ID=70395148
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201911326838.9A Active CN111090945B (en) | 2019-12-20 | 2019-12-20 | Actuator and sensor fault estimation design method for switching system |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN111090945B (en) |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN111638702B (en) * | 2020-05-10 | 2023-05-05 | 哈尔滨工程大学 | Non-conductive fault reconstruction method for constant tension system |
CN111812980B (en) * | 2020-07-02 | 2022-03-22 | 淮阴工学院 | Robust fault estimation method of discrete switching system based on unknown input observer |
CN111830943B (en) * | 2020-07-27 | 2022-07-29 | 华北电力大学 | Method for identifying faults of electric actuator of gas turbine |
CN112067925B (en) * | 2020-09-07 | 2023-05-26 | 淮阴工学院 | Real-time weighted fault detection method for boost converter circuit |
CN112799374B (en) * | 2020-12-24 | 2023-01-10 | 南京财经大学 | Design method of full-order fault estimation observer of Delta operator switching grain management system |
CN113031570B (en) * | 2021-03-18 | 2022-02-01 | 哈尔滨工业大学 | Rapid fault estimation method and device based on self-adaptive unknown input observer |
CN112947392B (en) * | 2021-04-05 | 2022-04-26 | 西北工业大学 | Flight control system actuator and sensor composite tiny fault estimation method based on robust observer |
CN113359438A (en) * | 2021-05-18 | 2021-09-07 | 浙江工业大学 | Two-axis engraving machine fault estimation method based on two-dimensional gain adjustment mechanism |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7254528B2 (en) * | 2002-05-14 | 2007-08-07 | Sun Microsystems, Inc. | Tool for defining verbs and adverbs in a fault injection test creation environment |
EP3132548B1 (en) * | 2014-04-15 | 2021-06-02 | ARRIS Enterprises LLC | Smart receivers and transmitters for catv networks |
CN108196532B (en) * | 2018-03-07 | 2020-06-26 | 山东科技大学 | Fault detection and separation method for longitudinal flight control system of unmanned aerial vehicle based on nonlinear adaptive observer |
CN108733030B (en) * | 2018-06-05 | 2021-05-14 | 长春工业大学 | Design method of switching time-lag system intermediate estimator based on network |
CN109471364B (en) * | 2018-12-28 | 2020-10-27 | 西安交通大学 | Reliable control method of nonlinear switching system with actuator fault |
CN110493031A (en) * | 2019-07-05 | 2019-11-22 | 湖北工业大学 | A kind of substation control system network device state on-line monitoring method |
CN110555398B (en) * | 2019-08-22 | 2021-11-30 | 杭州电子科技大学 | Fault diagnosis method for determining first arrival moment of fault based on optimal filtering smoothness |
CN110412975B (en) * | 2019-08-26 | 2021-05-25 | 淮阴工学院 | Robust fault diagnosis method for chemical liquid level process control system |
-
2019
- 2019-12-20 CN CN201911326838.9A patent/CN111090945B/en active Active
Also Published As
Publication number | Publication date |
---|---|
CN111090945A (en) | 2020-05-01 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN111090945B (en) | Actuator and sensor fault estimation design method for switching system | |
CN110209148B (en) | Fault estimation method of networked system based on description system observer | |
CN110703744B (en) | Fault detection method for chemical liquid level control system based on unknown input observer | |
Shi et al. | Quantized learning control for flexible air-breathing hypersonic vehicle with limited actuator bandwidth and prescribed performance | |
CN111812980B (en) | Robust fault estimation method of discrete switching system based on unknown input observer | |
CN110119588B (en) | On-line optimization design method based on extended Kalman filtering state estimation value | |
CN108762072B (en) | Prediction control method based on nuclear norm subspace method and augmentation vector method | |
Oliveira et al. | An iterative approach for the discrete‐time dynamic control of Markov jump linear systems with partial information | |
Doca et al. | A frictional mortar contact approach for the analysis of large inelastic deformation problems | |
Xu et al. | Conservatism comparison of set-based robust fault detection methods: Set-theoretic UIO and interval observer cases | |
Zhang et al. | Different Zhang functions leading to different ZNN models illustrated via time-varying matrix square roots finding | |
Huang et al. | Discrete‐time extended state observer‐based model‐free adaptive sliding mode control with prescribed performance | |
Butt et al. | Adaptive backstepping control for an engine cooling system with guaranteed parameter convergence under mismatched parameter uncertainties | |
Nguyen et al. | Neural network-based prediction of the long-term time-dependent mechanical behavior of laminated composite plates with arbitrary hygrothermal effects | |
Gu et al. | Parametric design of functional observer for second‐order linear time‐varying systems | |
Langueh et al. | Fixed‐time sliding mode‐based observer for non‐linear systems with unknown parameters and unknown inputs | |
Chen et al. | Finite‐time adaptive neural dynamic surface control for non‐linear systems with unknown dead zone | |
Zhu et al. | H∞ fault detection for discrete-time hybrid systems via a descriptor system method | |
CN111625995B (en) | Online time-space modeling method integrating forgetting mechanism and double ultralimit learning machines | |
Czajkowski et al. | Stability analysis of the neural network based fault tolerant control for the boiler unit | |
Farhat et al. | Fault detection for LPV systems: Loop shaping H_ approach | |
Feng | Spatial basis functions based fault localisation for linear parabolic distributed parameter systems | |
Li et al. | Fault tolerant shape control for particulate process systems under simultaneous actuator and sensor faults | |
Guo et al. | Output‐feedback boundary adaptive fault‐tolerant control for scalar hyperbolic partial differential equation systems with actuator faults | |
Leite et al. | Robust ℋ∞ state feedback control of discrete-time systems with state delay: an LMI approach |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant |