Patent ID: 8234051

Claim:
A driving-force control apparatus for a vehicle having an engine (E), a plurality of wheels, and a transmission (T), the driving-force control apparatus including a driving-force control means (M 8 ) for determining a state of a road surface on which the vehicle is running and for controlling a driving force of the vehicle based on the determined state of the road surface, the driving-force control apparatus comprising: a first low-friction-coefficient road-surface determination means (M 1 ) for determining whether the road surface has a low friction coefficient based on a highest wheel speed and a lowest wheel speed of the plurality of wheels; a second low-friction-coefficient road-surface determination means (M 2 ) for determining whether the road surface has a low friction coefficient based on wheel speeds of front and rear wheels of the plurality of wheels; a third low-friction-coefficient road-surface determination means (M 3 ) for determining whether the road surface has a low friction coefficient based on wheel speeds of left and right driving wheels of the plurality of wheels; a fourth low-friction-coefficient road-surface determination means (M 4 ) for determining whether the road surface has a low friction coefficient by comparing a reference vehicle-body acceleration calculated from a driving force of the engine (E) with an actual vehicle-body acceleration calculated from a measured number of revolutions of a differential gear (Df, Dr); a low-friction-coefficient road-surface total-determination means (M 5 ) for determining whether the road surface has a low friction coefficient based on the determination results of the first to fourth low-friction-coefficient road-surface determination means (M 1 to M 4 ); a grip-travel determination means (M 6 ) for determining whether the vehicle is running with good gripping based on the determination results of the first to fourth low-friction-coefficient road-surface determination means (M 1 to M 4 ) and a driving state of the vehicle; and a low-friction-coefficient road-surface suspect determination means (M 7 ) for determining whether there is a possibility that the road surface has a low friction coefficient based on the determination results of the low-friction-coefficient road-surface total-determination means (M 5 ) and the grip-travel determination means (M 6 ).