Investigation of different techniques for determining the road uphill gradient and the pitch angle of vehicles

This report presents different approaches to estimate the road uphill gradient and the vehicle pitch angle with the help of the vertical accelerometer, the longitudinal accelerometer and the wheel speed sensor, which are usually installed in modern vehicles. As the first attempt, only straight forward driving is considered here. All these approaches are developed based on mathematical models. The practicability of these techniques is investigated by car tests. In order to extend the operation area, a strategy to combine the different techniques is developed.