Patent · US Expired

Control apparatus for four-wheel drive vehicle

US4712635A · kind A · utility

20Cited by
3References
3Claims
0Family size

Assignees

Inventors

Key dates

Filing dateDec 29, 1986
Grant dateDec 15, 1987
Priority date
Expiry dateDec 29, 2006

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB60W2552/40
  • WIPO fieldTransport
  • WIPO sectorMechanical engineering

Abstract

The coefficient of friction of a road surface lying ahead of a four-wheel drive vehicle is predicted and, if control performed on the basis of the prediction is incorrect, the coefficient of friction of the road surface actually traversed by the vehicle is calculated, thereby revising the prediction so that the next prediction of coefficient of friction will be more accurate. Accordingly, control for changeover between two- and four-wheel drive or for locking a center differential mechanism can be made to conform to the road surface conditions immediately and in an appropriate manner to prevent skidding or lock-up of the tires and, hence, assure a safe and stable traveling state.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.