T-S model-based SMC reliable design for a class of nonlinear control systems

This paper studies the robust reliable control issues based on the Takagi-Sugeno (T-S) fuzzy system modeling method and the sliding-mode control (SMC) technique. The combined scheme is shown to have the merits of both approaches. It not only alleviates the online computational burden by using the T-S fuzzy model to implement the original nonlinear system (since most of the system parameters of the T-S model can be offline computed) but also preserves the advantages of the SMC schemes, including rapid response and robustness. Moreover, the combined scheme does not require online computation of any nonlinear term of the original dynamics, and the increase in the partition number of the region of premise variables does not create extra online computational burdens for the scheme. Under the design, the control mission can continue safely without prompt external support, even when some of the actuators fail to operate. Meanwhile, both the active and the passive reliable designs are presented. The proposed analytical results are also applied to the attitude control of a spacecraft. Simulation results demonstrate the benefits of the proposed scheme.