Improved prescribed performance control for nonlinear systems with unknown control direction and input dead-zone |
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| Authors: | Zongsheng Huang Tieshan Li Yue Long Hanqing Yang C L Philip Chen Hongjing Liang |
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| Affiliation: | 1. School of Automation Engineering, University of Electronic Science and Technology of China, Sichuan, China;2. School of Automation Engineering, University of Electronic Science and Technology of China, Sichuan, China
School of Computer Science and Engineering, South China University of Technology, Guangdong, China |
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| Abstract: | In view of the input dead-zone, unknown control direction and difficulty in satisfying the prescribed performance that suffered in practical systems, an improved prescribed performance-based adaptive control scheme is stressed for uncertain nonlinear systems in this paper. Firstly, by adopting a characteristic function, the input dead-zone is linearized to a model with bounded perturbation. To settle the “computation complexity” issue, an adaptive controller is built via command filter design method, where the fuzzy logic systems are introduced to approximate the unknown nonlinearities. Meanwhile, the Nussbaum function is brought in controller design to counter the hardship of unknown control direction. Besides, the tracking error can be restricted in the prescribed boundary in finite time with the improved performance function. The presented control approach can not only ensure the finite-time convergence property of tracking error and the boundedness of all signals in the closed-loop system, but also easily implement in engineering. Finally, the simulation examples confirm the validity of the designed control scheme. |
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| Keywords: | command filter finite-time performance function input dead-zone strict-feedback nonlinear systems unknown control direction |
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