Research On Specified-time Platoon Control For Networked Vehicles/Uavs System

The networked vehicle systems and the networked unmanned aerial vehicle(UAV)systems extende the environmental awareness of the subsystem by the platoon control approach.The accuracy platoon space,velocity of each vehicle,and the path planning can be realized by using the compact following strategy for networked vehicle systems,which can reduce the traffic jam,avoid long-term supersaturation of the roads.The compact following methods of distributed platoon control for the networked UAV systems can also save energy and improve endurance by reducing the wind resistance.Moreover,the networked UAV system expands the perspective of networked vehicle systems,which not only can provide more accurate road information,but also can form an interactive platform in the air to communicate with the networked vehicle systems.However,the current analysis of platoon control is focused on its internal steady-state analysis,which is called string stability.The system-oriented high-performance control method is not well explored under complex constraints,such as the convergence time,external disturbances,and parameter uncertainties.In view of this,this thesis considers specified-time platoon control for networked vehicles/UAV systems,the main research contents are given as follows:(1)For the vehicular platoon control systems with flexible distance constraints,a distributed controller based on dynamic gain is designed to achieve specified-time platoon control under flexible safety distance constraints.Firstly,for the networked vehicle platoon control problem modeled by a single integral model,a distributed platoon control strategy is proposed based on prescribed transient and steady-state performance control approach and time mapping,which can achieve the specified-time vehicle platoon control under the flexible safety distance constraint.The proposed approaches allow vehicles to converge to the platoon within any specified time without depending on the initial conditions or system parameters.The proposed controller using back-stepping method also can be applied for the networked vehicle systems with double-integral model under a flexible safe distance constraint.Finally,the relationship between the control inputs and the convergence time is given.(2)For the vehicular platoon control in a third-order dynamic networked vehicle system subjects to unknown external disturbances,specified-time convergent disturbance observer and controller are designed to achieve disturbance compensation and stable platoon control within a specified time.First,a disturbance observer based on dynamic gain is proposed to realize the specified-time observation of unknown disturbances.Furthermore,an disturbance compensation strategy based on dynamic gain is proposed,and the stability condition of the specified-time platoon is presented,which does not depend on the system parameters.(3)For the vehicular platoon control of a third-order dynamic networked vehicle system with flexible distance constraints and unknown disturbances at the same time,a firstorder disturbance observer with specified-time convergence and a predeterminedperformance controller are proposed to satisfy the flexible safety distance constraints under unknown disturbances.Firstly,a first-order disturbance observer based on dynamic gain is proposed,which realizes specified-time observation of unknown disturbance.Furthermore,a distributed platoon controller that can realize collision avoidance,connectivity maintenance and convergence at a spcified time is proposed.Safe and fast queue control of networked vehicle system.The proposed approach can simultaneously guarantee the specified-time convergence and connectivity maintenance without depending on any system parameters.(4)An adaptive control protocol with radial basis function neural network(RBFNN)and dynamic surface control technique is proposed to guarantee that the state errors can be stable within the zero neighborhood for the nonlinear networked UAV systems.First,the dynamic surface control technique and the RBFNN method are used to estimate the uncertainties.Then,the specified-time control scheme is proposed based on an embedding disturbance observer and adaptive dynamic surface control technique to guarantee the preperformance,communication connectivity,collision avoidance,and the specified convergence time simultaneously.Using the proposed control method,the closed-loop nonlinear system can be stabilized within the specified time and without depending on any system parameters.(5)A novel adaptive sliding mode disturbance observer is first designed for the networked UAV system with a radial basis function neural network(RBFNN)estimator.Then the dynamic gain technology is combined with the prescribed performance control to design the novel platoon controllers for the networked UAV system.With the proposed disturbance observer and the distribute controller,the platoon can be achieved with the communication range constraint.The proposed approach can simultaneously guarantee the specified convergence time and prescribed performance without any initial conditions.