Sliding Mode Observer and Control System Design

Abstract

Due to its distinct feature and robustness heritage the sliding mode control theory receives wide attention in control system research and applications Its distinct properties achieved by discontinuous switching control action are established when the ideal sliding motion takes place The concept of sliding mode control has extended to the problem of state estimation known as the sliding mode observer which possesses the merits of sliding mode dynamics When system attains to the sliding surface the system dynamics are totally independent of the matched uncertainties or disturbances called the invariance property This dissertation synthesizes a sliding mode observer scheme and it applies to a 4D chaotic system under different conditions This shows that the observer has satisfactory performance and can updates the system parameters under specific assumptions In addition the systems with unstable invariant zeros and mismatched uncertainties are considered It reveals that the mismatched uncertainties will degrade the estimation accuracy and even result in system instability The proposed sliding mode observer guarantees the stability and maintains the superior performance with the observer gains optimized by the LMIs technique The robust observer is also applied to the control of a mechanical system to demonstrate the feasibility and advantages of the proposed design scheme

Date of Award	2014 Aug 22
Original language	English
Supervisor	Chieh-Li Chen (Supervisor)