Research On Active Collision Avoidance Control Strategies For Vehicles In Adjacent Vehicle Cutover

As an essential part of active vehicle safety technology,active collision avoidance systems can effectively reduce crashes and have received widespread attention from major vehicle manufacturers and research institutes.However,most of the current active collision avoidance systems do not sufficiently consider the influence of dynamic obstacles or road constraints when making behavioural decisions and collision avoidance control,and can hardly cope with complex driving conditions.Therefore,it is necessary to conduct an in-depth study on the intervention timing and intervention mode of collision avoidance systems,as well as collision avoidance local path planning methods.The thesis proposes an active collision avoidance behaviour decision strategy based on the safety distance model analysis for the dangerous scenario of neighbouring vehicle cut-in,designs active braking and active lane change collision avoidance control strategies,and conducts simulation experiments to verify the proposed control strategies.Firstly,the neighbouring car cut-in scenario is analysed,and the hazardous conditions are judged according to the Time To Collision(TTC)and Anti-collision Safe Distance in Cut-in Scene(AS)models,and a decision is made on the collision avoidance mode under the hazardous conditions.The AS model is validated by varying the initial speed of the vehicle,the speed of the cut-in vehicle and the road adhesion coefficient,and conducting simulation experiments.Based on the principle of throttle and brake pressure control,an active braking collision avoidance control strategy is designed and simulation experiments are conducted on roads with different road surface adhesion coefficients,and the results show that the proposed active braking collision avoidance control strategy can effectively achieve active collision avoidance.In order to solve the problem of unreachable target and local minimum of the traditional artificial potential field,the proposed artificial potential field method is proposed to improve the path planning of lane change collision avoidance,change the repulsive potential field function,solve the problem of unreachable target and local minimum of the traditional artificial potential field,increase the repulsive potential field of the road boundary to ensure that the vehicle can still keep driving in a straight line in the middle of the road after the end of collision avoidance,introduce the speed adjustment factor,and establish the dynamic obstacle potential field to achieve collision avoidance path planning in dynamic scenarios.The vehicle speed,cut-in vehicle speed and cut-in angle are changed and simulation experiments are carried out to verify the proposed lane change collision avoidance path planning strategy.Based on the model prediction control algorithm,a linear time-varying prediction model in the finite time domain is established,and constraints are placed on the lateral deflection angle of the centre of mass,the maximum lateral acceleration and the lateral deflection angle of the tyre,etc.A lane change collision avoidance path tracking controller is designed,and simulation experiments are carried out by varying the vehicle speed and road adhesion coefficient.The results show that the designed lane change avoidance path controller can achieve active lane change path tracking and meet the vehicle stability requirements.The research results of the paper can provide theoretical and practical basis for the study of vehicle collision avoidance control strategies.