Patent Number: 6,254,204

Title: Device for measuring longitudinal acceleration of vehicle immune to static and dynamic errors

Abstract: A first signal is obtained by detecting speed of wheels of a vehicle to indicate the wheel speed. On the other hand, a second signal is obtained by detecting longitudinal acceleration to directly indicate longitudinal acceleration of the vehicle. A third signal indicating the change rate of the wheel speed is obtained by differentiating the first signal by time. The third signal is sensitive to a small convex or concave of the road surface but not sensitive to a longitudinal inclination of the road surface. The second signal is not sensitive to a small convex or concave of the road surface but is sensitive to a longitudinal inclination of the road surface. Then, a fourth signal is obtained from the second signal by filtering low frequency components off therefrom, while a fifth signal is obtained from the third signal by filtering high frequency components off therefrom. Then, a final longitudinal acceleration signal is obtained by composing the fourth and fifth signals together. It will be desirable that a cutoff frequency of the low pass filtering is lowered when a brake locking has occurred.

Inventors: Hara; Kouichi (Susono, JP), Kagawa; Kazunori (Toyota, JP), Kanagawa; Akiharu (Nogoya, JP)

Assignee: Toyota Jidosha Kabushiki Kaisha

International Classification: B60T 8/17 (20060101); B60T 8/171 (20060101); B60T 8/172 (20060101); G01P 15/16 (20060101); G01P 15/08 (20060101); G01P 15/00 (20060101); B60T 008/38 (); B60T 008/58 ()

Expiration Date: 07/03/2018