SLIPPAGE CONTROL SYSTEM USING ESTIMATED ROAD SURFACE RESISTANCES

A vehicle slippage control system has wheel drive torque controlled so as to prevent drive wheels from excessively slipping on a road and is regulated in accordance with road surface resistances. The system estimates lateral and rectilinear road surface resistances on the basis of lateral and rectilinear gravitational acceleration of the vehicle, respectively, and then selects one of the estimated lateral and rectilinear road surface resistances, on the basis of predetermined terms, as an effective road surface resistance in accordance with which wheel drive torque is changed.