| 摘要 |
PROBLEM TO BE SOLVED: To determine rapidly and more accurately whether a road is bad or not. SOLUTION: With a complex function, a wavelet transformation is made of vehicle deceleration G so as to detect the time at which its phaseθvaries from 2πto 0, as time t1 for a first maximum of the deceleration G, and the time at which the phaseθbecomesπ, as time t3 for a first minimum of the deceleration G. By computing a first integral S1 from the first maximum to 0 for the deceleration G and a second integral S2 from the 0 to the first minimum, when an absolute value of the ratio (S2/S3) is larger than a threshold, a road is determined to be bad. The determination is based on the dependence of the deceleration G in the bad road on vibrational elements. Whether the road is bad or not can be satifactorily and rapidly determined by the computation up to the time for the first minimum. Misdetection due to noise and the like can be also prevented by the detection of the times for the first maximum and minimum, employing the wavelet transform.
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