Adaptive robustSMC of hybrid robot for automobile electro‐coating conveying

Abstract

For a novel hybrid robot for automobile electro‐coating conveying, an adaptive robust sliding‐mode controller is proposed to improve the control performances and counteract the influences of uncertainties including modelling error, friction, and external disturbance. One remarkable feature of the controller lies in that it does not require the boundary of the uncertainties in the hybrid robot by designing a novel gain adaptation law. The law is capable of dynamically adjusting control gains to avoid selecting excessively bigger values of the control gains, and further attenuating the chattering phenomenon of the super‐twisting sliding‐mode control (SMC) simultaneously. Moreover, disturbance observer is used to estimate and compensate various uncertainties to further improve the robustness of the control system. The stability of the designed control algorithm is proved by Lyapunov stability theorem. The simulation and experimental results show that the adaptive robust SMC has superior tracking performance and is able to attenuate the chattering phenomenon effectively in the presence of modelling error, frictions, and external disturbances.