Reasearch On Vehicle Stability Layered Integrated Control Strategy Based On Braking And Suspension System

With the increasing demand of safety performance by the automobile consumers,automobile-manufacturers are paying constant attention to the active safety of automobiles.As the control of the yaw and roll is becoming a major project in the active safety research field.By integrating the control of the yaw and roll,the stability of vehicles can be effectively maintained.This dissertation firstly analyzes the lateral dynamics and longitudinal dynamics of the vehicle,then an 8DOFs vehicle model including yaw and roll motion,the H.B.Pacejka tyre model and the hydraulic system model were established.By simplifing the vehicle model,the 2DOFs and 3DOFs vehicle model as the referential model and predicted model for the control system were established.Secondly,this dissertation seeks to discuss the use of yaw velocity as the control target,combining with direct yaw control and fuzzy control theory to design the yawing stability system.Then,the TTR rollover prediction system as the superior control system to switch the yawing and rollover control system was built.Meanwhile,with the TTR rollover prediction system,the rollover stability system was established.By using the direct yaw control and suspension,the rollover stability of the vehicle was kept.Then,this dissertation integrates the yawing and rollover control system using the TTR,the strategy of the integration is that when the TTR which calculated from rollover prediction system is less than the reference value,opening the rollover control system only,otherwise,the yawing control system will operate normally.In the Matlab/Simulink software,By choosing the law slip rate sideslip driving condition and high slip rate rollover driving condition,the effectiveness of the integrated control strategy is tested through the simulation.Finally,based on dSPACE hardware-in-the loop simulation test bench,the simulation on different typical condition is further carried out.The result shows the integrated control strategy can effectively improve the vehicle stability.