Center of gravity height real-time estimation for lightweight vehicles using tire instant effective radius

Center of gravity (CG) height is an important parameter for lightweight vehicles (LWVs). Because of the inherently smaller weight and size, a LWV's CG height is more easily affected by loading conditions compared with conventional vehicles. This paper proposes a novel tire instant effective radius (TIER) method for real-time estimation of the CG height for LWVs. The method utilizes the mathematical correlation between the tire vertical load transfer that is proportional to the CG height, and the TIER variation. A Kalman filter based estimator is designed to simultaneously identify the vehicle CG height as well as the unknown nominal tire effective radius. To verify the performance of the proposed estimator, simulation results are first provided for several vehicles with different CG heights, and then road test results obtained on a lightweight electric ground vehicle (EGV) equipped with an advanced measurement system are given. Both simulation and experimental results show that the developed estimator is capable of providing an accurate estimation of the vehicle CG height in real-time.