Vehicle Abs System, The Maximum Longitudinal Adhesion Coefficient Estimation Algorithm

With the development of science and society, performance of automobile braking system is highly required, especially the anti-lock brake system (ABS). Because it can make the vehicle achieve the minimum brake distance on most of the road. Now the ABS is used more and more widely and many manufacturers are developing the new ABS.During braking instant ,ABS can avoid the tire locking and ensure the lateral stability and turning steering at the time of braking when the vehicle urgent braking.So the ABS system has more developmental prospects.The paper anatomized the control principle of ABS Firstly ,and based on it introduced the structures, species, every part functions of ABS.Basing on automobile dynamic theory,the paper analysed the relation of the adhesion and slide rate when braking and the factor of affect,and analysed the relation of the adhesion and slide rate with the modle of LuGre.With the analysis above,we can ensure the point of the best slide rate.The paper sets up the parameter of the state of road surface—θand the observatory of the state of road surface,and simulates it with the software of Matlab/Simulink. The result indicates that the observator can estimate the state of road surface real-timely in order to ensure the point of the best parameter of adhesion in the braking.So,it is likely to crotroling the parameter of adhesion about the best parameter of adhesion.The control way based on the best parameter of adhesion has its advantage that we only need to get the sensor information of the wheel speed in order to estimate the state of the road surface, so that we can crotroling the parameter of adhesion about the best parameter of adhesion.It can enhance the braking effect and the security in briking.