Anti-lock braking system based on an estimated gradient of friction torque, method of determining a starting point for anti-lock brake control, and wheel-behavior-quantity servo control means equipped with limit determination means
US6122585A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 13, 1997 |
| Grant date | Sep 19, 2000 |
| Priority date | — |
| Expiry date | Aug 13, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60T2210/12
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
An anti-lock braking system includes a friction torque gradient estimating unit for estimating, from a small number of parameters, the gradient of friction torque with respect to a slip speed, and controls a braking force acting on wheels on the basis of the friction torque gradient estimated by the friction torque gradient estimating unit. The friction torque gradient estimating unit may employ several types of estimating methods; e.g., a method of estimating the gradient of friction torque from only time-series data concerning a wheel speed; a method of estimating the friction torque gradient from time-series data concerning wheel deceleration as well as from braking torque or time-series data concerning physical quantities associated with the braking torque; or a method of estimating the friction torque gradient from micro-gains which are obtained when brake pressure is excited in a very small amount at the resonance frequency of a vibration system comprising a vehicle, wheels, and a road surface and which represent the characteristics of the vibration system. Further, there is also disclosed a method of determining, from the thus-estimated friction torque gradient, the limit of…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.