There is provided a tire ground contact pattern specifying method and an
apparatus thereof for specifying a tire ground contact pattern usable to
perform the stable control of a running vehicle. Using a sensor unit 100
mounted in each tire 2 of a vehicle 1, accelerations generated in X, Y
and Z directions are sensed and at the same time, a low frequency noise
component and high frequency noise component added to the Z axis
direction acceleration signal are extracted. Digital values being the
sensing result are transmitted as digital information to a monitor device
200 by radio wave. The monitor device 200 compares many pieces of tire
ground contact pattern information preliminarily stored with the digital
information to thereby specify a tire ground contact pattern. A stability
control unit 700 performs, based on the acceleration values and the
information on tire ground contact pattern obtained, the correction
control of driving of a sub-throttle actuator 412 or a brake drive
actuator 640.