Time Optimal Model Predictive Control Of Nonlinear System

As model predictive control developing up to now,predictive control of linear systems has been relatively mature,and it can effectively dealing with constraint system,optimizing goal,makes the online computation quantity is small enough,widely used in industrial process,but in fact,most of industrial process system is nonlinear,the complexity,the multiplicity and uncertainty of nonlinear system factors,which make the stability,robustness,an online optimization computation complexity are increased greatly,so this article in view of the nonlinear system with constraints,proposed the time optimal nonlinear model predictive control algorithm,used to solve the optimization of nonlinear system,the details is as follows:(1)Based on Jacobian linearization to linearization of nonlinear system is able to derivation a series of convex optimization problems,and the linearized error under Lipschitz conditions determine the scope of the upper boundary.Then adopts the dual model control strategy,in the case of offlines structure to describe a series of ellipses set t feasible region,each balance of ellipsoid set according to the last ellipsoid,then online ccording to the appropriate input calculate the system stable.Using backstepping calculation method can ensure the feasibility and stability of the iteration,the numerical examples show that algorithm greatly reduces the computational burden,to prove the effectiveness of the algorithm.(2)For a class of constrained nonlinear systems based on multiple linear model,first of all,based on the gap metric within the operation range through the gridding point of nonlinear system,and then determine the smallest set of linear model library can get a series of linear model,this kind of linear model can precise estimate the nonlinear system,secondly,according to the robust constraint model predictive control algorithm,under the offline condition each model can design an offline local controller,which can be structure a series of the ellipsoid set;Online calculation suitable input,where the initial state can reach the target area as soon as possible,and the way of offline calculation can reduce the online computation burden,which make the optimization solution can be faster and more efficient,online condition in different sub models of thestructure conversion between ellipsoid range to ensure the stability of the closed-loop system.The continuous stirring reactor to verify the feasibility of the algorithm.