Variable gear ratio steering system
US6155377A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 1998 |
| Grant date | Dec 5, 2000 |
| Priority date | — |
| Expiry date | Jul 29, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/19575
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
In a variable gear ratio steering system, a control unit determines the steering angle ratio which is to be achieved by the steering angle ratio varying unit according to a condition of the vehicle with respect to a given road condition. Such vehicle conditions may include a road surface frictional coefficient so that an excessive steering may be avoided on slippery road surfaces by increasing the steering gear ratio under such conditions. Such vehicle conditions may also include a side force utilization ratio of the steerable wheels so that an excessive steering may be avoided when there is little margin in the available side force for the steerable wheels. The steering system may include a CCD camera for determining the lateral position of the vehicle relative to the current driving lane and a control unit for determining the predicted lateral travel of the vehicle, typically from the steering input angle and the vehicle speed, so that the steering gear ratio may be increased when the vehicle has traveled or drifted sideways more than predicted. Thereby, the vehicle is prevented from inadvertently drifting out of the driving lane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.