Estimation And Measurement Of Sideslip Angle For Vehicle Stability Control

Vehicle sideslip angle is critical for many active safety systems such as VehicleDynamics Stability Control System (DSC), yaw stability control, rollover prevention andlane departure avoidance. Therefore, estimation of vehicle sideslip angle based on thevehicle input/output signals is an important topic. In this paper, the sideslip angle’sestimation and measurement is researched and based on the research and hardware resourceof the Vehicle Dynamics and Control Group in Tsinghua University. The general contentsof this paper can be summarized as follows:Utilizing linear2degrees of freedom vehicle model, continuous and discrete stateobserver have been built of vehicle sideslip angle, and High friction lane change simulationis carried out using a nonlinear15degrees of freedom vehicle model of the VehicleDynamics and Control Group. The simulation results show that the two state estimationobservers work well when the tire is in linear region, but don’t work well when the tire is innonlinear region.Utilizing Kalman filtering theory, linear and extend Kalman filter have been developedfor lateral speed, and then sideslip angle has been calculated. In contract with linear Kalmanfilter, Extend Kalman Filter (EKF) is based on Simplified “HSRI” tire model in which areconsidered the load transfer, vertical load, surface friction and slip rate. The simulationresults show that EKF works well for nonlinear tire dynamics.Also, a real-time measurement of vehicle sideslip angle is developed usingdual-antenna GPS. Detailed experimental results show that the method and data collectorcan reliably measure slip angle in Lane Change Test and Steady State Circular Test.