Research On Anti-rollover Control Of A Heavy Vehicle Based On Co-Simulation

With the increasing development of the highway network construction and heavy-duty vehicle market,the rollover accidents of heavy-duty vehicle continue to increase. Thus the vehicle stability causes a lot of scholar’s attention. However,research on rollover formation mechanism and heavy-duty vehicle rollover control method is still in its infancy in China. And the research on heavy-duty vehicle anti-rollover control strategy is also rare. Therefore, study on heavy-duty vehicle anti-rollover control is beneficial to enhancing driving safety of vehicle, and has important theoretical significance and broad application prospects.When the vehicle gets a large steering angle input at high speed on a dry road,vehicle lateral acceleration and the lateral load transfer rate will increase sharply,which will cause rollover easily.Therefore, this dissertation puts emphasis on the driving conditions of large angle input and high speed for heavy-duty vehicles.Meanwhile, the impact of vehicle parameters on rollover stability and anti-rollover control strategy are studied. Details of this dissertation are as follows:Firstly, heavy-duty vehicles model with linear tire model is established.It contains three degrees of freedom, describing the vehicle’s lateral, yaw and roll motion. Differential equations of vehicle are converted to state space model with modern control theory. Then, simulations are made in typical operating conditions to analysis the rollover risk of vehicle model. By variation of important vehicle parameters such as roll angle, lateral acceleration, yaw rate, side slip angle and tire load transfer rate, the sensitivity of the vehicle parameters to vehicle rollover stability is investigated.Then, a nonlinear virtual prototype model of a domestic heavy-duty vehicles is established in ADAMS / CAR, including front and rear suspension, steering system,tire systems, brake systems, power-train and vehicle body. Meanwhile, the model considers non-linearity of the tires, shock absorbers, springs and other parts of thevehicle. Typical driving conditions are simulated to verify the virtual prototype mode To improve the rollover stability of heavy vehicles at high speeds, an anti-rollover control strategy is designed in Matlab by using differential braking system to control the lateral load transfer rate. Taking LTR as the control objective, the controller can generate the appropriate torque by differential braking to improve rollover stability and yaw stability of vehicle.Finally, the result of simulation is analyzed based on ADAMS-Matlab co-simulation for virtual prototype model of vehicle. Some typical conditions,with different speed, steering wheel angle input, curve radius, road adhesion coefficient(dry asphalt, wet concrete, snow and ice) are simulated. Simulation results show that this anti-rollover control strategy can improve the rollover stability and handle stability of heavy-duty vehicles.