Predefined‐Time Adaptive Output Feedback Control of Nonlinear Systems Under Input/Output Quantization

ABSTRACT In this article, for a class of uncertain nonlinear systems, an adaptive predefined‐time output feedback tracking control problem is investigated. Both the input signal and the output signal of the system are quantized for the sake of a lighter communication burden. First of all, a dynamic filtering technology is applied to overcome the virtual control signals being directly differentiated. Secondly, a well‐constructed observer powered by quantized output and input is devised, which can help resolve the difficulty of immeasurable states. Thirdly, an adaptive output feedback control scheme is put forward under the backstepping design framework. Compared with the current predefined‐time design methods, the adaptive law designed in this paper is expressed as a nonlinear differential equation, which ensures the predefined‐time stability. It is shown that all the signals in a predefined time interval are bounded and the controlled system is practically predefined‐time stable (PPTS). Ultimately, the effectiveness of the suggested control algorithm is illustrated through two examples.