Model based detection of tyre deflation by estimation of a virtual transfer function

In the last years a lot of efforts have been done to develop monitor systems for the detection of a tyre deflation, because many accidents are caused by a tyre pressure drop. Though the systems, which are based on pressure sensors, have a rather high accuracy, they weren´t accepted because of their high price. To avoid special pressure sensors, a new method for the classification of tyre pressure is presented, which estimates a virtual transfer function between the vertical accelerations of the front and rear axis. This approach doesn´t require the form of the actual road surface as an input signal, which normally isn´t available. The magnitude of the presented virtual transfer function itself depends on the tyre pressure in a significant way, so that observing a certain threshold will be sufficient to detect a tyre deflation