Fixed-Time Dynamic Surface-Based Adaptive Composite Control for Nonlinear Systems and Its Application to the RLC Circuit

This brief investigates the fixed-time dynamic surface-based adaptive composite control issue for nonlinear systems subject to unknown constants. With the help of the adaptive technology, unknown parameters for the system are approximated. Then, using the serial-parallel estimation models (SPEMs), the forecast biases and the track biases can change adaptive laws and the fixed-time approximate characteristics for unknown parameters will be improved. Introducing the backstepping method, a novel adaptive fixed-time composite controller design scheme is proposed. Moreover, it can make all the closed-loop signals bounded and the system tracking error incline to a small region near zero within fixed-time interval. In the end, the simulation results will be provided to further prove the utilizability of the designed control scheme.