A Combined Hard and Soft Variable-Structure Control Scheme for a Class of Nonlinear Systems

作者：Su Juhng Perng^*; Lee Ting En; Yu Ker Wei

来源：IEEE Transactions on Industrial Electronics, 2009, 56(9): 3305-3313.

DOI：10.1109/TIE.2009.2023634

• Alpha-beta filter
• fuzzy control
• magnetic levitation system
• variable-structure control (VSC)

This paper presents a novel variable-structure-based control scheme for nonlinear systems. First, a hard variable-structure control is constructed for achieving a uniform ultimate boundedness control. Then, a soft variable-structure control using fuzzy logic is incorporated to help improve dynamic responses when trajectories enter into the ultimate bound. For practical consideration, we added a genetic-algorithm-based alpha-beta filter in front of the fuzzy controller to suppress noise and obtain smooth input signals. For comparison purposes, an inverted pendulum system was first used as a simulated example to demonstrate the effectiveness of the design. Then, the performance of the control scheme was practically tested with an experimental PC-based magnetic levitation system. The simulation and experimental results strongly suggest that the newly proposed control scheme is encouraging for practical applications.

• 出版日期2009-9