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Full-Text Articles in Controls and Control Theory
Fast And Low-Frequency Adaptation In Neural Network Control, Yongping Pan, Qin Gao, Haoyong Yu
Fast And Low-Frequency Adaptation In Neural Network Control, Yongping Pan, Qin Gao, Haoyong Yu
Yongping Pan
In adaptive neural network (NN) control, fast adaptation through high-gain learning rates can cause high-frequency oscillations in control response resulting in system instability. This paper presents a simple adaptive NN with proportional-derivative (PD) control strategy to achieve fast and low-frequency adaptation for a class of uncertain nonlinear systems. Variable-gain PD control without the knowledge of plant bounds is proposed to semiglobally stabilize the plant so that NN approximation is applicable. A low-pass filter-based modification is applied to the adaptive law to filter out high-frequency content so that tracking performance can be safely improved by the increase of learning rates. The …
Output Feedback Adaptive Neural Control Without Seeking Spr Condition, Yongping Pan, Meng Joo Er, Rongjun Chen, Haoyong Yu
Output Feedback Adaptive Neural Control Without Seeking Spr Condition, Yongping Pan, Meng Joo Er, Rongjun Chen, Haoyong Yu
Yongping Pan
For output-feedback adaptive control of affine nonlinear systems based on feedback linearization and function approximation, the observation error dynamics usually should be augmented by a low-pass filter to satisfy a strictly positive real (SPR) condition so that output feedback can be realized. Yet, this manipulation results in filtering basis functions of approximators, which makes the order of the controller dynamics very large. This paper presents a novel output-feedback adaptive neural control (ANC) scheme to avoid seeking the SPR condition. A saturated output-feedback control law is introduced based on a state-feedback indirect ANC structure. An adaptive neural network (NN) observer is …