Research On The Automotive Crosswind Stability And The Control Of The Crosswind Stability Consider The Location Of The Center Of Pressure

With the car in everyday life is becoming increasingly popular, the current speedof the car is improving people’s cars with security requirements have become moresophisticated, so the impact of cars with the air forces of the cars are also more tomore attention. Car in motion the process often encounter lateral aerodynamic force,the nature of the effects of crosswinds are often unstable, especially the impact on thecar’s high-speed car is very large, it will directly affect driving safety car. Car speedby the highway between col mountainous areas, bridge piers or between largebuildings in the cities, are likely to encounter greater strength crosswind effects; carsovertaking, small cars and large cars the car will. When the car out of the tunnel willcrosswind rats. In the case of high speed driving, the driving force of the longitudinalvehicle tire adhesion of the car will increase, and due to the aerodynamic lift force ofthe impact, so that the adhesive side is further reduced. Therefore, under suchcircumstances, the forces and moments by the side effects of the wind generated byautomobile body will produce larger changes in the trajectory of the automotivevehicle and the state will be affected, the operation stability of the vehicle will have agreater impact. For the impact of the current stage pneumatic crosswind stabilitystudies of the car is still relatively small.This paper is the study taking into account the pressure center drift in a carcrosswind stability and crosswind stability control study using active controltechnology for cars. Pressure center car is equivalent aerodynamic center, in theactual cars with the process, due to the location of the randomness of natural windaerodynamic center of pressure will change over time, so in this paper will considerthe impact of the position of the center of pressure in this article in order to study thecrosswind crosswind stability control of system stability and impact of active control,the paper uses the integrated image modeling. In order to study the active controlmethods to improve the crosswind stability of high-speed vehicle, established theeight degrees of freedom nonlinear vehicle dynamic model under crosswind, theinfluence of different aerodynamic crosswind conditions on driving the car, andestablished two degrees of freedom model based on piecewise linear tire features as areference model. It designed an active front steering (AFS) controller based onflexible PID control and a direct yaw moment control (DYC) controller based on LQR Optimal control. Comparative analysis of the two kinds of typical operatingconditions in two different active control methods for high-speed vehicle crosswindstability control. The results show that: on driving straight crosswind conditions, DYCon performances of maneuverability, stability, ability to keep track is superior to AFS,but AFS is superior to DYC in longitudinal dynamic; on crosswind front cornercondition, AFS and DYC have few difference on performances of maneuverability,stability and, but AFS significantly better than DYC.