A Cost-Effective Sideslip Estimation Method Using Velocity Measurements From Two GPS Receivers

This paper demonstrates that the vehicle sideslip can be estimated through the kinematic relationship of velocity measurements from two low-cost GPS receivers. To compensate for the low update rate of low-cost GPS receivers, acceleration/angular rate measurements from an inertial measurement unit (IMU) are merged with the GPS measurements using an extended Kalman filter (EKF). Two technical challenges were addressed: 1) unsynchronized updates of the two GPS receivers and 2) significant delays in GPS velocity measurement. A stochastic observability analysis reveals that the proposed method guarantees the observability when a vehicle has nonzero yaw rates. Experimental verification shows that the vehicle sideslip is estimated regardless of surface friction levels under several maneuvers.