Detecting moisture on road surface from vehicle - detecting water spray noise or wheel rolling noise, bandpass filtering, forming effective value, low-pass filtering, compensating for other parameters e.g. speed or tyre pressure and relating to wetness.

摘要

The method involves detecting the noise of water spray or the rolling noise of at least one wheel of a vehicle as it is driven over the surface. The noise sensor's output signal is band-pass filtered to isolate a frequency range characteristic of moisture on the road. The effective value of the filtered signal is formed and passed through a low-pass filter. The effective value is associated with a value for the moisture on the road whilst compensating for the influence of parameters other than moisture on the effective value. The moisture value is output. USE/ADVANTAGE - Enables continuous measurement of moisture on road surface for use in vehicle, e.g. by anti-lock braking system.