A Novel Longitudinal Speed Estimator for Fully Automation Ground Vehicle on Cornering Maneuver

For a fully automation ground vehicle, the accurate longitudinal speed becomes more and more important due to the increasing demands on tracking of position, velocity and acceleration. Based on low-cost wheel speed encoders, this paper proposes a novel longitudinal speed estimator for vehicles on cornering maneuver. In the estimator, a gain-varying Kalman estimator is designed to output lateral states of vehicle body. On its basis, the side slip dynamics of tyres are modeled and then the relationship between wheel absolute speed and wheel angular speed is obtained. Subsequently, we calculate the longitudinal speed at center of gravity by using a planar vehicle model to describe the kinetic motion of vehicle body. With a passenger car equipped with differential GPS and other on-board sensors, a series of cornering experiments are carried out and demonstrate the success of the proposed estimator.