The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 10, 2002
Filed:
Sep. 29, 1999
Shoji Ito, Susono, JP;
Eiichi Ono, Aichi-gun, JP;
Masaru Sugai, Aichi-ken, JP;
Takaji Umeno, Aichi-gun, JP;
Katsuhiro Asano, Aichi-gun, JP;
Hiroyuki Yamaguchi, Aichi-gun, JP;
Satoru Onozawa, Kariya, JP;
Other;
Abstract
A wheel velocity signal for each wheel detected by a wheel velocity sensor is input to a bandpass filter. Signals from frequency bands unrelated to the unsprung resonance are then removed from the wheel velocity signal and only signals from frequency bands related to the unsprung resonance are output. A road surface &mgr; gradient estimation device uses an online identification method to identify an damping ratio of a second order resonance model similar to a suspension—tire resonance model from the signal output from the bandpass filter. The road surface &mgr; gradient is then estimated from the identified damping ratio. The damping ratio of the second order resonance model corresponds to the road surface &mgr; gradient in the following manner: when the damping ratio is identified as being small, the road surface &mgr; gradient is estimated as being large; and when the road surface &mgr; gradient is identified as being large, the damping ratio is estimated as being small.