Browsing by Author "Tsai, Che-Lun"

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Study of VSC reliable designs with application to spacecraft attitude stabilization
(2007-03-01)
Liang, Yew-Wen
;
Xu, Sheng-Dong
;
Tsai, Che-Lun
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This brief investigates variable structure reliable control (VSRC) issues of a set of second-order nonlinear systems and their application to spacecraft attitude stabilization. Both passive and active reliable designs are presented. To achieve the active task, an observer to identify faults as they occur in the spacecraft actuators is also presented. These VSRC laws do not require the solution of a Hamilton-Jacobi (HJ) equation, which is essential in the optimal approaches such as linear quadratic Riccati (LQR) and H-infinity reliable designs. As a matter of fact, this approach can relax the computational burden for solving the HJ equation. Simulation results regarding spacecraft attitude stabilization with comparisons among the VSRCs and the LQR reliable designs are also given. It is shown from these simulations that the active VSRC is the most flexible, robust and effective method because it does not need to prespecify susceptible actuators and because it allows more space for the control parameter adjustment.
VSC reliable design with application to spacecraft attitude tracking
(2005)
Liang, Yew-Wen
;
Xu, Sheng-Dong
;
Chu, Tzu-Chiang
;
Tsai, Che-Lun
;
Cheng, Chiz-Chung
This study investigates variable structure reliable control issues of nonlinear systems and its applications to spacecraft attitude tracking problems. Both passive and active reliable control laws are proposed using Variable Structure Control (VSC) technique. The passive one must know which group of actuators is allowed to fail, while the active one must accompany a fault detection and diagnosis (FDD) scheme. Both the reliable controllers need not the solution of Hamilton-Jacobi equation or inequality, which are essentials in optimal approaches such as reliable LQR and H-infinity designs. As a matte of fact, the VSC approach is able to relax the computational latency in control law computing. The proposed reliable designs are also applied to spacecraft attitude tracking problems to explain their effectiveness and benefits. Finally, simulation results and comparisons between LQR and VSC reliable designs are given to illustrate the merits of the proposed scheme.