Disturbance Observer Based Finite-time Anti-disturbance Control For System With Disturbance

Disturbances are ubiquitous in the actual system and will cause unpredictable effects on the system performance.In addition,performance requirements such as control accuracy and convergence speed of the controlled system in a complex environment are becoming more and more stringent.Hence,how to effectively deal with disturbances,to improve the convergence speed and control accuracy of the system is an urgent problem.On the basis of this background,disturbance observer-based control(DOBC)scheme is utilized to consider the finite-time anti-disturbance control for a class of systems affected by various disturbances.The main contents of the paper are as follows:Firstly,the finite-time anti-disturbance control for systems with disturbance and nonlinearity is discussed.The known information of the disturbance is utilized to construct the disturbance observer(DO)to achieve the disturbance observation.Then on the basis of disturbance estimation,a finite-time anti-disturbance control(FTADC)is presented by combing with the implicit Lyapunov function method,which ensures the globally finite time stable of the composite system.Secondly,the finite-time anti-disturbance control is concerned for system subject to multi-source disturbances,which consists of disturbance with unknown model parameters and uncertain bounded disturbance.Firstly,the disturbance with unknown model parameters is evaluated by designing the adaptive disturbance observer(ADO).Then,combined with the implicit Lyapunov function method,a disturbance observer based finite-time control strategy(DOBFTC)is constructed,which makes the composite system global finite time stability with multiple disturbances.Thirdly,a command filtering finite-time anti-disturbance control scheme is put forward for nonlinear system with multiple disturbances.The DO and extended state observer(ESO)are designed to evaluate the above disturbances,respectively.Then the command filtered finite-time anti-disturbance control(CMFTADC)scheme is designed by using the command filtered backstepping control scheme to make the tracking error converges to the bounded concentration in finite time.