Detection of roof load for automotive safety systems

The performance and design of lateral stability systems in cars depend on the ratio between the height of the center of gravity and the wheel base. This ratio is car specific, but a roof load can affect this and decrease the stability margins. We investigate the use of vehicle roll dynamics to detect and estimate changes in the overall sprung mass as well as the load positioned on the roof. It is assumed that the vehicle is equipped with a lateral accelerometer and a roll gyro, and a second order physical model is derived. The parameters in this model are partly unknown, and here estimated with a greybox and an ARMAX approach. The changes in load distribution can be detected and the approach is supported by experimental data in a lab environment.