To provide a road surface roughness detector based on a detection signal from a sensor even when any frequency analysis (FFT: Fast Fourier Transform) or the like is not performed.
The road surface roughness is detected by using the detection signal of an acceleration sensor 22 which is originally provided on a tire pneumatic pressure detector. More specifically, the AC element is extracted from the detection signal of the acceleration sensor 22, the AC element is rectified, and the road surface roughness is detected from the voltage signal according to the amplitude of the signal. According to the road surface roughness detection method, the road surface roughness can be detected based on the detection signal of the acceleration sensor 22 even when the frequency analysis (FFT) or the like is not performed. Thus, the state of the road surface roughness can be detected only by providing a small number of additional components to an existing system by utilizing the acceleration sensor 22 mounted on a transmitter 2 of a direct type tire pneumatic pressure detector which has been mounted on automobile extensively in recent years.
Takahiro Miura
Fumihiro Mizuno