Research On Vehicle Anti-rollover Control Strategy Based On Vertical Tire Force Prediction

Due to the popularity of cars in recent years,the incidence of traffic accidents is increasing year by year and the ratio of the casualty rate of the rollover accident is very high.Rollover prevention system acts as an important research on the automobile active safety technique.Its aim is to reduce vehicle's rollover accident rate and the death rate of the traffic accidents,improve the safety level of the vehicle,promote the automobile electrification and automation and the direction of intelligence development by controlling the chassis subsystem.Therefore,the research on rollover evaluation,prediction and control strategy based on tire vertical force is of great significance for improving vehicle active safety performance.First of all,the vehicle rollover dynamics model is established including three degrees of freedom vehicle dynamics model,driver model,active steering system model and differential braking system model.Secondly,the simulation and comparison of multiple working conditions are taken for common rollover evaluation indexes.As the existing indicators of vehicle rollover process description is not accurate enough,a new type of vertical tire force rollover evaluation index is put forward and then the PVTF rollover warning index is designed merging the fusion derivative and iterative prediction theory.In order to ensure the accuracy of the prediction index,the optimal selection of the prediction time and iteration steps is carried out.Lastly,considering external disturbances,sensor noise and the influence of controller response time of the anti roll control system,a two degree of freedom robust rollover prevention controller is designed based on the PVTF index,the active front steering system and differential braking system and H_?robust control theory.Merging active steering system,differential braking system,rollover evaluation unit and controller module,the anti rollover threshold control system based on PVTF index is built.The research contents in this paper can provide theoretical support for the research and development of vehicle active safety system.