Adaptive command filtered fixed-time control of nonlinear systems with input quantization

Highlights：

• Unlike existing adaptive quantized control schemes [29, 30, 31, 32], an improved hysteretic quantizer is introduced to decrease the number of transitions and mitigate the chattering issues. Moreover, the quantizers can be allowed to change at any time.

• Many well-studied results related to input quantization [31, 32, 33, 34, 35] require the sign of control gain to be known a priori. However, the phenomenon of unknown control gains is ubiquitous in practical application. To overcome this restriction, a Nussbaum-type function is incorporated into the adaptive fuzzy command filtered controller to identify the unknown control direction.

摘要

•Different from the finite-time command filtered backstepping literature [25, 26, 27, 28], the fixed time stability can be achieved by the proposed command filtered control scheme in this paper. Moreover, the settling time is independent of the initial condition. Besides, an inequality shown in Lemma 2.5 has been proposed to the stability analysis.•Unlike existing adaptive quantized control schemes [29, 30, 31, 32], an improved hysteretic quantizer is introduced to decrease the number of transitions and mitigate the chattering issues. Moreover, the quantizers can be allowed to change at any time.•Many well-studied results related to input quantization [31, 32, 33, 34, 35] require the sign of control gain to be known a priori. However, the phenomenon of unknown control gains is ubiquitous in practical application. To overcome this restriction, a Nussbaum-type function is incorporated into the adaptive fuzzy command filtered controller to identify the unknown control direction.