Sliding Mode Control Based On Microscopic Traffic System

Research on transportation systems mainly starts at macroscopic and microscopic perspective.From the macroscopic perspective,traffic flow is considered as a compressible continuous fluid medium consisting of a large number of vehicles.For this purpose,it is necessary to convert the information of individual vehicles into the overall information of the traffic flow,so that the collective behavior of the traffic flow composed of vehicles can be studied.From the macroscopic perspective,people focus on the behavior of individual vehicles.Microscopic variables such as the position,velocity and acceleration of the vehicle are used to study the relationship between vehicles.This study mainly focuss on the control of traffic flow and platoon control of multi-vehicle systems in microscopic traffic system to improve the smoothness and stability of microscopic traffic system.Since traditional control strategies have limitations in terms of control performance,stability,and robustness,considering the real-time demands of traffic system control,new control strategies with high efficiency and robustness need to be studied to improve the smoothness and stability of the traffic system.Therefore,the study on sliding mode control of microscopic traffic systems has important theoretical and practical significance,which can provide theoretical basis and decision-making basis for improving the smoothness and stability of traffic systems.This study focus on the sliding mode control problem based on microscopic traffic systems.On the one hand,applying sliding mode control theory and Lyapunov stability theorem,an exponential sliding mode control algorithm based on microscopic traffic model is proposed.The effectiveness of the sliding mode control algorithm is verified by numerical simulation experiments.On the other hand,for the multi-vehicle system model,a sliding mode control algorithm based on terminal sliding mode control theory and Lyapunov stability theory is proposed to realize the platoon control of multi-vehicle system.Finally,numerical simulation experiments verify the effectiveness of sliding mode control in the formation of multi-vehicle systems.The main work of the study includes the following two aspects:1.Regarding the microscopic traffic model,a sliding mode control algorithm based on exponential reaching law is proposedThis study proposes a sliding mode controller for vehicular traffic flow based on a microscopic traffic model to enhance the smoothness and stability of traffic flow evolution.In particular,the full velocity difference(FVD)model is used to capture the characteristics of vehicular traffic flow.The proposed sliding mode controller is designed in terms of the error between the desired space headway and the actual space headway between the leading and following vehicles.The stability of the controller is guaranteed using the Lyapunov technique.Numerical experiments are used to compare the performance of sliding mode control(SMC)with that of feedback control.The results illustrate the effectiveness of the proposed SMC method in terms of the distribution smoothness and stability of the space headway,velocity,and acceleration profiles.They further illustrate that the SMC strategy is superior to that of the feedback control strategy,while enabling computational efficiency that can aid in practical applications.2.Regarding the formation of multi-vehicle systems,a control algorithm based on terminal sliding mode control is proposedThis study proposes a finite-time robust platoon control strategy for multi-vehicle systems with bounded uncertain dynamics.Different from existing works,the proposed approach guarantees both the closed-loop system stability and finite-time convergence of the system error with strong robustness to uncertain dynamics of the electronic throttle valve and unknown varying accelerations of preceding cars.With the finite-time robust controller,two main results are obtained with rigorous mathematical proofs:(1)when the acceleration of the preceding cars are zero,the position and velocity errors will converge to zero in a finite time;(2)when the acceleration of the preceding cars are nonzero,unknown and bounded,the system errors are bounded,and the explicit bounds for velocity error are analytically given.Simulation results are provided to illustrate the effectiveness of the proposed approach in the presence of unknown disturbances and acceleration.