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Adaptive unit vector control of multivariable systems using monitoring functions
Author(s) -
Hsu Liu,
Oliveira Tiago Roux,
Cunha José Paulo V. S.,
Yan Lin
Publication year - 2018
Publication title -
international journal of robust and nonlinear control
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.361
H-Index - 106
eISSN - 1099-1239
pISSN - 1049-8923
DOI - 10.1002/rnc.4253
Subject(s) - control theory (sociology) , multivariable calculus , overshoot (microwave communication) , trajectory , transient (computer programming) , state vector , tracking error , disturbance (geology) , adaptive control , tracking (education) , computer science , mathematics , control (management) , control engineering , engineering , physics , psychology , telecommunications , paleontology , pedagogy , classical mechanics , artificial intelligence , astronomy , biology , operating system
Summary An adaptive sliding‐mode unit vector control approach based on monitoring functions to deal with disturbances of unknown bounds is proposed. An uncertain multivariable linear system is considered with a quite general class of nonsmooth disturbances. Global stabilization/tracking is demonstrated using either state or output feedback. The proposed adaptation method makes the control gain less conservative, becoming large enough when the disturbance grows and becoming smaller when it decreases, leading to reduced chattering effects. In contrast to previous methods, the new switching scheme is able to guarantee a prespecified transient time, maximum overshoot, and steady‐state error for multivariable uncertain plants. The proposed technique is applied to the trajectory tracking control of a surface vessel subjected to ocean currents, wind, and waves. Simulations are presented to show the performance of the new adaptation scheme in this adverse scenario of possibly growing, temporarily large, or vanishing exogenous disturbances.