The invention provides a traction control system and sensor unit thereof
which easily and highly accurately senses accelerations generated
vertically, longitudinally and laterally in a wheel to control the drive
of the vehicle. A sensor unit provided with an acceleration sensor
sensing accelerations generated in association with rotation in the X, Y
and Z directions including the rotation direction is disposed in a body
of rotation of a rotation mechanism section including each tire NO, and
the sensing result, a digital value, is transmitted as digital data by
use of radio wave. The digital data is received by a monitor apparatus
disposed in each tire house and is subjected to arithmetic processing.
The acceleration value thus obtained is outputted to a drive control
unit. Based on the acceleration value obtained and distortion
characteristic data preliminarily stored, the drive control unit
estimates the amount of distortion of each tire, and based on the
estimated amount of tire distortion and the sensing result of the number
of rotations of each tire, controls a sub-throttle actuator to drive a
sub-throttle.