Global fixed-time event-triggered control for stochastic nonlinear systems with full state constraints

This paper is devoted to solving the global fixed-time event-triggered stabilization problem for a class of nonstrict-feedback stochastic systems with full state constraints. Firstly, the nonlinear state constrained system is converted into a novel constrained free system with the help of nonlinear mappings, which eliminates the feasibility conditions of virtual control signals while satisfying the state constraints. Secondly, a lemma about the variable separation technique is put forward to deal with unknown nonlinear terms in stochastic systems, which avoids the restrictive growth assumption that unknown functions need to be satisfied. Then, a fixed-time event-triggered control strategy based on the symbol function technique is designed by combining the backstepping method with the fixed-time stability theory of stochastic systems. It is proved that all closed-loop signals are globally fixed-time stable in probability. Finally, a numerical example and a single-link robot system are simulated to verify the availability and feasibility of the developed approach.