Research On The Roll Stability Of Commercial Vehicles Based On Differential Braking

In China,with the rapid economic development,the road traffic system gradually improved,the commercial vehicles as an important part of transportation,its demand increased year by year.Heavy vehicles especially for its own structural characteristics in the steering,changing lane and overtaking at high speed,vehicles are in a non-linear area,which prone to rollover traffic accidents,resulting in serious personal safety and property losses.In order to improve the driving safety of the vehicles,the paper chooses the two-axle heavy-duty vehicle to design the appropriate anti-rollover control system for the research object,and to improve the anti-rollover ability of the vehicles.The paper mainly studies the following points:(1)Analysis the rollover stability mechanism of the heavy vehicle,the two-axle heavy-duty vehicle model with the same vehicles operation is established in Trucksim software.According to the theory of vehicle dynamics,the vehicle is simplified and the three-degree of freedom rollover model is established in Matlab/Simulink software.Under the typical conditions the vehicle models are co-simulated,the results show that the model can describe the actual dynamic characteristics of the vehicles in the non-linear area,and also confirm the feasibility and correctness of the vehicle model and the three-degree of freedom rollover model.(2)It is proposed that the lateral load transfer rate as the rollover index and the running direction of the vehicle is judged by the positive and negative of the lateral load transfer rate.Through the design of the rollover conditions to achieve the anti-rollover control of the vehicles.According to the principle of differential braking,the front and outer wheel of the vehicle is selected as the control target.Two additional yaw moment controllers are designed with the yaw rate error and the rate of change as the control variable as the input of the controller.(3)According to the corresponding test standards,the vehicle model,the three-degree of freedom rollover model and the differential braking anti-rollover control system were co-simulated under two kinds of limit conditions respectively.Through the comparison and analysis of several parameters and control effects that characterize the state of vehicle movement,the simulation results show that the anti-rollover control system designed in the paper can effectively prevent the rollover of the heavy vehicles under different conditions,thereby improving the anti-rollover ability of the vehicle.