The traction control method involves monitoring of the wheel speed and detecting the slip condition from the variations in wheel speed. The actual slip limit is compared with the calculated slip limit and with the road speed signals. The oscillations in the wheel speed are derived from the monitored values. The system also detects high frequency, low amplitude oscillations. The control system continuously updates the road grip values without additional sensors and without additional programmed values. The oscillations are characterised e.g. the phase differences of the oscillations are deduced.
