Observer Design for Estimating Road Elevations at All Tire Contact Patches Using Only an Inertial Sensor

This paper designs an observer for estimating road elevations at all tire contact patches using only an inertial sensor with high accuracy, comparable to that of laser scanning. The observer is constructed within the framework of the unknown input Kalman filter to estimate road elevations, which act as disturbances to vehicle dynamics. The model for the observer is based on vertical-pitch-roll dynamics, encompassing road elevations at all tire contact patches. The introduction of virtual measurements for all tires ensures the observability of the model in the inertial sensor-based observer without requiring both additional sensors and model simplification. Additionally, a bias model is added to compensate for sensor installation errors for practical realization. Experimental validation demonstrates that the proposed observer can estimate road elevation with high accuracy, regardless of vehicle speed and dynamics, even when utilizing only an inertial sensor, making it suitable for rapid and robust road maintenance.