Fault-Tolerant Quantized Sliding Mode Observers Design for a Class of Takagi-Sugeno Fuzzy System With Unmeasurable Premise Variable

This article addresses the state and fault estimation problems for a class of quantized Takagi–Sugeno (T-S) fuzzy systems with sensor and actuator faults. Two types of observer design methods are developed for two different network transmission environments. In the first case, the signal quantization effect is only considered on the channel between sensor and controller, and a sliding mode observer is designed, which can reconstruct the actuator faults. In the second case, the quantization effects are considered in both the sensor-controller side and the controller-actuator side, which is more difficult to be dealt with compared to the first case, and the sliding mode observer method cannot be effective now since the discontinuous term is difficult to be designed. A descriptor reduced-order observer is presented to solve this problem, where the jumping behavior that resulted from the signal quantization is considered in the observer, which is novel and effective to compensate the quantization effects. Finally, simulation examples of rigid-body satellite attitude control T-S fuzzy system are presented to verify the effectiveness of the proposed observer design approaches.