Adaptive output-feedback control of an uncertain strict-feedback time-delay system

作者：Si, Wenjie; Dong, Xunde; Zeng, Wei

来源：Systems Engineering and Electronics, 2017, 39(6): 1325-1333.

DOI：10.3969/j.issn.1001-506X.2017.06.22

• Adaptive Control
• Adaptive output-feedback control
• Barrier lyapunov functions
• Dead zones
• Output constraints
• Radial basis function neural networks
• Semi-globally uniformly ultimately bounded
• Strict-feedback nonlinear systems

This paper investigates the problem concerning tracking control for a class of single input and single output uncertain strict-feedback nonlinear systems, under the condition of the input dead-zone and output constraint with unknown time delays. Firstly, a state observer is established to estimate the unmeasured states. Secondly, radial basis function neural networks are used to approximate the unknown nonlinearity;a barrier Lyapunov function is designed to ensure that the output parameters are restricted and the effects of unknown time-delays are eliminated by choosing appropriate Lyapunov-Krasovskii functions in the design procedure. Finally, based on Lyapunov stability theory, a robust adaptive neural network output feedback controller is constructed. The designed controller overcomes the problem of over-parameterization. It is shown that the designed control scheme can ensure that all the closed-loop signals are semi-globally uniformly ultimately bounded and the tracking error converges to a small neighborhood of the origin. Two examples are provided to further show the effectiveness of the proposed approach.

• 出版日期2017-6-1
• 单位华南理工大学