Tracking Control Of Euler-Lagrange Systems With Severe Uncertainties

This paper is devoted to the tracking control of uncertain Euler-Lagrange systems.The existing results are strictly restricted by the strong assumptions on system uncertainties,or the considerations which only focus on the steady performance but regardless of the transient one.For this,a time-varying feedback compensation mechanism for severe system uncertainties and prescribed transient performance are developed,which relaxes the restrictions on system uncertainties and performance indexes.Specifically,a tracking controller is designed by using the constructive method based on funnel set,which ensures the desirable steady performance(such as the convergence or the boundedness of the tracking error)while the prescribed transient one(such as the tracking accuracy,regulation time of convergence rate);by using vector backstepping method while introducing time-varying function in the estimation of system signals,a time-varying controller is designed to overcome the serious uncertainties from disturbance and unknown parameters while guarantee that that all states of the closed-loop system are bounded and the system output asymptotically tracks the given reference signal.Moreover,a dynamic model of disturbed rotating pendulum system is established by using the dynamic and static method and the relative motion principle.Then,by combining the backstepping method with the adaptive dynamic compensation mechanism and the disturbance learning and switching compensation mechanism,practical tracking and asymptotic tracking controllers are respectively developed to ensure that all states of the closed-loop system are bounded while the system output tracks to the given reference signal.Finally,simulation examples are provided to validate the effectiveness of the theoretical results.