Tire pressure control with vibration parameters

The present system of tyre pressure control is based on monitoring vibrational parameters. These parameters characterize the system consisting of tyre, undamped masses, spring/damper and body. Three physically independent parameters are analysed which depends typically on the tyre pressure. Measuring signals are the vertical accelerations of the center of the wheels which are analysed in the frequency range. The first method look to a special defined transfer function in the range of 15 Hz to 35 Hz, which is proper for tyre pressure information. Additionally theses transfer function is independent of the mode of excitation. The second method deals with a oszillation of tyre. The characteristic frequency of this oscillation drops from about 100 Hz to about 75 Hz when the tyre pressure goes down from 3.0 bar to 1.0 bar. The third method analyses the growing unbalance which comes up with decreasing tyre pressure. All three methods are able to work independent and parallel in time. Information about decreasing tyre pressure are only given if all parameters has uniformity changes.