Distributed Model Predictive Control Schemes Of Nonlinear Platooning Systems

Platooning systems are equipped with sensors,communication units,controllers,actuators,etc.,which have superior performance in improving mobility and safety of mobile bodies,reducing energy consumption,and rapid formation control.Meanwhile,distributed control of platooning systems relies on network communication among mobile bodies.This implies that the communication quality and communication topologies have important influence on control of platooning systems.On the basis of the recalling the literatureat at home and abroad,this dissertation considers the cooperative control problem of nonlinear platooning systems subject to state and control constraints and communication concerns.By adopting the input-tostate stability property,average-dwell time method,string stability property,the dissertation study distributed model predictive control strategies of nonlinear platooning systems.The main work of the dissertation is as follows.(1)For the problems of information transmission delays and energy-efficiency of nonlinear platooning systems,the distributed economic model predictive control strategy is proposed for multi-agent nonlinear systems with time-delay.The Lyapunov-based coupled contractive constraints are established by employing the states and delayed information received from neighbors of subsystems.By giving the economic performance index,the finite horizon economic optimal control problem is established for the platooning system with time-delay.The input-to-state stability(ISS)property is used to rigorously prove the stability of each subsystem and the generalized small gain condition is used to prove the stability of the whole system for both strongly and weakly connected network.Finally,the effectiveness of the proposed strategy is illustrated by some comparison simulation.(2)For the changing communication topology problem of nonlinear platooning system,the distributed model predictive control strategy is proposed for heterogeneous vehicle platooning systems with switching topologies.Combining dynamic communication topologies,the time-dependent graph function is established.Then the average cooperative costs function and receding horizon optimization problem are defined by using the state information of vehicles in neighbor set.On this basis,the concept of average dwell-time is adopted to establish sufficient conditions for the internal stability and string stability of the platooning system with changing communication topologies.The effectiveness of theoretical results are verified by numerical simulation.(3)For the problems of string stability and scalability of nonlinear platooning systems,the DMPC strategy is proposed for scalable platooning systems.By taking into account the unidirectional predecessor-following communication topology,the notions of “Regional String Stability(RSS)” and “Regional Scalable String Stability(SRSS)” are defined via the information from each preceding vehicle,which describe the control performance of vehicle platooning systems.By the Lyapunov function perporties,some sufficient conditions are derived to guarantee the RSS and SRSS perporities of the vehicle platooning system.The validity of the results is verified by simulation.