DSP-Based Sliding-Mode Control for Electromagnetic-Levitation Precise-Position System

作者：Lee Jeng Dao; Khoo Suiyang; Wang Zhi Bin

来源：IEEE Transactions on Industrial Informatics, 2013, 9(2): 817-827.

DOI：10.1109/TII.2012.2219062

• Digital-signal-processor (DSP)
• electromagnetic levitation
• exact estimator
• lumped uncertainty estimator
• sliding-mode control
• terminal sliding-mode control

This paper investigates the robust tracking control problem for a bipolar electromagnetic-levitation precise-position system. The dynamic model of the precise-position device is derived by conducting a thorough analysis on the nonlinear electromagnetic forces. Conventional sliding-mode control and terminal sliding-mode control strategies are developed to guarantee asymptotic and finite-time tracking capabilities of the closed-loop system. A lumped uncertainty estimator is proposed to estimate the system uncertainties. The estimated information is then used to construct a smooth uniformly ultimately bounded sliding-mode control. An exact estimator is also proposed to exactly estimate the unknown uncertainties in finite time. The output of the exact estimator is used to design a continuous chattering free terminal sliding-mode control. The time taken for the closed-loop system to reach zero tracking error is proven to be finite. Experiment results are presented, using a real time digital-signal-processor (DSP) based electromagnetic-levitation system to validate the analysis.

• 出版日期2013-5