The Research On Active Fault-tolerant Control Based On Inverse System Method

In this paper, as the study of nonlinear systems, active fault-tolerant control problems are studied based on inverse system method of the SISO system and MIMO system, mainly carried out research in the following areas:1) For certain priori knowledge fault of nonlinear systems, in order to solve the multi-model active fault-tolerant control system in response to an unknown fault of the fast control law calculation problem, proposes an active fault-tolerant control using multi-models based on Radial Basis Function (RBF) inverse system internal model methods. The method first uses RBF set up inverse system modeling for normal and faults with each kind of prior breakdown situation, then buildes inverse model bank for dynamic systems, based on inverse model of inverse system method connect the system become one pseudo-linear system, and designes with a good robust performance of the internal model controller. Actual run-time system, the decision-making mechanism of monitor is being calculated and analysis based on system performance indicators and model of tolerance mismatch index, The diagnosis system locates the movement pattern, call switching RBF inverse model, the system has always been seried with inverse model and remain unchanged pseudo-linear system, thus no need to change the situation of internal model controller for nonlinear systems and to achieve active fault-tolerant control purpose.2) For priori knowledge of the actual system faults and other problems is not easy to obtain, an approach of fault diagnosis and accommodation based on RBF inverse system method is designed. Through the design of RBF inverse model of nonlinear plant estimates actuator fault, while RBF inverse model connect the nonlinear plant become pseudo-linear system, and the introduction of internal model control. Estimates using fault acting on the inverse of the paint and to generate the corresponding compensation, and finally to the plant and the compensated inverse series can maintain the same pseudo-linear system, so no need to change the system in the normal control parameters of the case, in order to achieve the purpose of fault tolerant control through the inverse system method of compensation.3) For the real system with uncertainty and a variety of time-varying faults, the small sample of LS-SVM modeling method for systems is introducted using inverse modeling, using data-driven control idea and model free adaptive control method, design a compensation controller for real-time compensation when system parameter perturbation or fault occur, the system without changing the main controller parameters in the cases of adaptive inverse compensation method, allows the system output can accurately track the reference output.4) For the state space form of multi-variable nonlinear reversible systems, inverse system method is introducted, and a method based on inverse system of multi-variable nonlinear system fault diagnosis is proposed, through the design of nonlinear robust sliding mode observer device to achieve state estimation, and combined with inverse system method, to achieve the implementation of multi-variable nonlinear system fault diagnosis. On the basis of further design of the controller design based on inverse system method, the ultimate the inverse system is accommodated by the fault estimates, to achive MIMO system fault-tolerant control purpose.