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.