Simulation Study Of Transverse-longitudinal Control System For Intelligent Vehicles

Intelligent vehicles are at the forefront of research in the field of vehicle engineering and a new direction for the future development of the automotive industry.They are also an important component of intelligent transport systems,which can effectively reduce the incidence of traffic accidents,improve the safety and comfort of driving and alleviate the current energy shortage and environmental pollution.Motion control is one of the core issues in the field of intelligent vehicles,and is also the focus of subsequent research and development,which mainly involves transverse control,longitudinal control and integrated horizontal and vertical coordination control.This paper focuses on the study of transverse-longitudinal control of intelligent vehicles,and the main work is as follows:(1)Establish vehicle transverse dynamics model and vehicle trajectory tracking model,obtain feedforward front wheel turning angle based on curvature feedforward control,design feedback controller based on transverse deviation and heading deviation joint-standing sliding mode control theory,combine feedforward and feedback to obtain vehicle trajectory tracking controller,design upper level transverse moment based on nonsingular terminal sliding mode control theory with transverse angular velocity deviation and mass lateral deviation angle deviation as input Based on the non-singular terminal sliding mode control theory,the upper level transverse moment controller is designed with the deviation of the transverse swing angular velocity and the deviation of the mass centre side deflection as inputs,and the quadratic lower level moment distribution controller is designed based on the minimum sum of the longitudinal tyre force utilisation.The simulation is validated by a joint simulation between Carsim and Simulink under two different road conditions: low-speed snow and ice and high-speed dry asphalt.The simulation results show that the designed controller is able to track the trajectory well,improving the driving safety of the vehicle and reducing tyre wear.(2)The vehicle longitudinal controller is designed using a direct control structure.The longitudinal dynamics model of the vehicle and the longitudinal speed tracking model of the vehicle are first established.The final results show that the controller can achieve the vehicle speed tracking well and ensure the comfort of the occupants.(3)Adopting the parallel transverse-longitudinal control system structure,combined with the establishment of the previous vehicle transverse-longitudinal dynamics model,the vehicle longitudinal controller is designed based on PID control theory,and the vehicle transverse controller is designed based on LQR control theory,and the longitudinal speed is used as the coupling point of the transverse-longitudinal control system.The simulation results show that the tracking accuracy of the vehicle is high and appears at the corresponding turn,which is in line with the reality.It can be seen that the designed integrated transverse-longitudinal controller can track the desired trajectory well and ensure the comfort of the ride and the stability of the vehicle.