Approximation-based adaptive control of uncertain non-linear pure-feedback systems with full state constraints

作者：Kim Bong Su^*; Yoo Sung Jin

来源：IET Control Theory and Applications, 2014, 8(17): 2070-2081.

DOI：10.1049/iet-cta.2014.0254

• adaptive control
• nonlinear control systems
• uncertain systems
• constraint theory
• Lyapunov methods
• constraint satisfaction problems
• control system synthesis
• function approximation
• closed loop systems
• state-space methods
• approximation-based adaptive control
• uncertain nonlinear pure-feedback system
• full state constraint
• nonaffine nonlinear function
• dynamic surface design
• integral barrier Lyapunov functional
• tracking performance
• constraints satisfaction

This study proposes an adaptive approximation-based control approach for non-linear pure-feedback systems in the presence of full state constraints. Completely non-affine non-linear functions are considered and assumed to be unknown. The dynamic surface design based on integral barrier Lyapunov functionals is provided to achieve both the desired tracking performance and the constraints satisfaction, in consideration of the full-state-constrained non-affine non-linearities. In this design procedure, simple sufficient conditions for choosing control gains, which can be checked off-line, are established to guarantee the feasibility of the controller. The function approximation technique is employed to estimate unknown non-linearities induced from the controller design procedure where the adaptive laws using the projection operator are designed to ensure the boundedness of the function approximators in the feasibility conditions. It is shown that all the signals in the closed-loop system are uniformly ultimately bounded and the tracking error converges to an adjustable neighbourhood of the origin while all state variables always remain in the constrained state space.

• 出版日期2014-11-20