Abstract :
In this paper, discrete-time quasi-sliding-mode control systems are considered. A new definition describing the quasi-sliding mode as a motion of the system, such that its state always remains in a certain band around the sliding hyperplane, is introduced. Then, two novel reaching laws satisfying conditions of the definition are proposed and applied to the design of appropriate linear control strategies which drive the state of the controlled system to a band around the sliding hyperplane. Consequently, the undesirable chattering and high-frequency switching between different values of the control signal are avoided. The strategies, when compared with previously published results, guarantee better robustness, faster error convergence, and improved steady-state accuracy of the system. Furthermore, better performance of the system is achieved using essentially reduced control effort
Keywords :
control system synthesis; discrete time systems; robust control; variable structure systems; definition; discrete-time quasi-sliding-mode control strategies; error convergence; linear control strategies design; reaching laws; robustness; sliding hyperplane; steady-state accuracy; Algorithm design and analysis; Automatic control; Control systems; Convergence; Digital control; Internet; Robustness; Shape; Sliding mode control; State-space methods;