Nussbaum-based robust adaptive control for nonlinear switching systems with switching unknown control coefficients

This paper develops a robust adaptive dynamic surface control (DSC) design approach for switching strict feedback nonlinear systems with multiple switching control gains and unknown control directions. To capture the multiple unknown control directions, we design multiple Nussbaum-type gains for every subsystem. Based on this Nussbaum-type gain design, we construct a common Lyapunov function for all subsystems via backstepping technique, which can ensure the system stability under the existence of random switches. Meanwhile, the problem of multiple switching control gains is resolved by this means. To obviate repeated differentiation and decrease computation complexity, the dynamic surface control technique is introduced. Finally, two simulation examples are provided to validate the effectiveness of the developed method.