Research Of Information Fusion Control Technology For Underactuated System

The control problem of the underactuated system is the main concerned of this dissertation, and a control method based on information fusion estimation theory is proposed for the problem. The main idea of this method is that transform the typical underactuated control problem into optimal control problem which the quadratic performance index contains the constraints of the output error and control energy, and then the information fusion estimation theorem is used to solve the linear or nonlinear optimal control problem, at last, the estimation of the optimal control value is obtained. The main research work focuses on the following aspects.Firstly, a design process of the nonlinear information fusion controller is proposed. The selection problems of information weight matrix, prediction steps and initial filter value is discussed, and several design guides about information fusion controller is summed up, such as, the information weight matrix only has relative meaning, increase or decrease the weight matrix at the same time does not infect the control performance; in general, the number of prediction step is bigger, the used information is greater, and the control effect is better; the contribution to the control effect will reduce gradually with the prediction step increasing, at the same time the calculation load of the controller will increase, so the prediction step should be selected properly.Secondly, for the problem of expected control value in the quadratic performance index function is non-zero, a kind of promotion information fusion method is put forward. For the control problem with input saturation, an anti-saturation control method based on soft constraint of control energy adaptive adjustment is proposed. For the problem of part of states in the control system is not observed, an observer design method based on information fusion estimation is presented. For the control problem of nonlinear system with environmental disturbance or uncertain parameter, by using the disturbance compensation, adding perturbation constraints in performance index, and constructing auxiliary control system effectively improve the robust performance of information fusion control algorithm.Thirdly, for the underactuated system consist of levers and links, an information fusion tracking controller of overhead crane was designed and researched, the simulation result verified the effectiveness of the information fusion controller. For the problem of the steady-state tracking performance of the information fusion controller deteriorate when crane’s load changes, the traditional PI regulator and information fusion controller are combining used to improve the tracking performance of the crane system.At last, for the underactuated system with lateral movement restricted, an information fusion tracking controller of surface vessel was designed and researched. Simulation shows that the information fusion controller has a certain robust performance for the environment disturbance. For the control problem of surface vessel with non-matching parameters perturbation, a robust information fusion control method is proposed, if the disturbance satisfying some condition, by a series of transformation, the robust tracking control problem of surface vessel can be transformed into optimal control problem of an auxiliary system with augmented control variables, and the effectiveness of this method is verified by simulation.Above all, the information fusion control algorithm has a good control effect for underactuated system, and has a broad application prospect.