PURPOSE: To always obtain appropriate reducing function of driving force at generating slip regardless of atmospheric pressure by correcting a control quantity of an engine output control means so as to gradually enlarge accompanied with a fall of atmospheric pressure.
CONSTITUTION: When a slip condition is detected from difference of rotating speed of driving wheels (a right front wheel 3 and a left front wheel 4) and driven wheels (a right rear wheel 5 and a left rear wheel 6), a traction control unit 33 respectively outputs control signals for reducing the slip to a brake control unit 31 and an engine output control unit 32. Hereby, prescribed brake force is applied on the driving wheels 3, 4, engine output is lowered by a prescribed quantity, the driving force transmitted from the respective driving wheels 3, 4 to the road surface side is reduced, and the slip is prevented. In the above- stated constitution, when the atmospheric pressure falls, the reducing control quantity of engine output by the engine output control unit 32 is further corrected on the increase side.
OIZUMI YUTAKA
SHITANI YUJI
