Research On Mixed Logical Dynamical Model And Its Model Predictive Control

Many industrial processes contain not only continuous variables but also discrete ones, which were traditionally treated as separate parts. However, interactions between these two kinds of variables are often observed in real processes, which urge the need of a new modeling framework that is capable of dealing with this complex condition. A system whose behavior is modeled as the interaction between continuous systems and discrete-event systems is called Hybrid System. The research on hybrid systems provides new idea and method for complex issues. This work is about modeling and control of hybrid systems.After describing general characteristics of hybrid systems, we review several common hybrid system models such as Hybrid Automata, Hybrid Petri nets, Mixed Logical Dynamical Systems and so on. A comparison among them is given.The rest of the work concentrate mainly on modeling and control design based on Mixed Logical Dynamical Systems. Firstly, we prove the equivalence between logical proposition and its equivalent linear inequalities. System dynamics, logical rules and constraints can be integrated into a whole framework based on these equivalent conversions.Secondly, Mixed Logical Dynamical (MLD) method is implemented to describe several typical hybrid systems. Integrate models are provided within this framework. We investigate the optimal control of MLD systems. An optimal control method based on state space system is given. We also apply Model Predictive Control (MPC) based on MLD systems and the convergence of Receding Horizon Control is studied. Several numerical simulations are given to improve the feasibility and effectiveness of the algorithm.Thirdly, we study the Mixed Logical Dynamical K-T steering model, including the dead zone of electro-hydraulic telemotor, and its MPC strategy. To more explicitly explain the effectiveness of the mixed logical model, an improved Dynamic Matrix Control approach based on K-T steering model is presented first. The simulation results show that the former approach is more preferable to the latter one when dealing with the dead zone of electro-hydraulic telemotor.At the end of this paper, the research work is summarized, and prospects for future research works are outlined.