Method for recognizing roof rack mounted at right and left rail bar of roof rail in roof of motor car, involves making determination to check whether roof rack is mounted or not from measurement signal curves of piezo element

摘要

The method involves attaching a piezo element (5) to left and right rail bars (3a, 3b) of a roof rail (3) of a roof (2) of a vehicle (1), and exciting the rail bars or structural elements to mechanical vibrations with a predetermined vibration generating frequency, where the structural elements are mechanically coupled with the roof. Decaying oscillation of the rail bars of the roof rail and the structural elements of the vehicle is detected by the piezo element. A determination is made to check whether a roof rack (4) is mounted or not from measurement signal curves of the piezo element. The piezo elements are activatable as piezo actuators.