A proposal for a variable structure adaptive backstepping control

This paper presents a proposal for a Variable Structure Adaptive Backstepping Control (VS-ABC). Instead of traditional integral adaptive laws for estimating the plant parameters, switching laws are used to increase robustness to parametric uncertainties and disturbances, as well as, to improve transient response. Moreover, the controller design is easier when compared with the original adaptive backstepping controller, since the amplitude relays are related to the plant nominal parameters. This new approach, using variable structure, also reduces the practical implementation complexity, encouraging the use of industrial embedded components, such as, FPGAs (Field Programmable Gate Arrays), MCUs (Microcontrollers) and DSPs (Digital Signal Processors). Additionally, preliminary simulation results for an unstable first order system are shown.