Abstract: A traction control algorithm for four wheel drive is presented. Based on the configuration of hardware for traction control system, an algorithm for calculating reference vehicle speed, a controller for engine throttle with PI method, and an algorithm for brake with logic threshold method are devised. At the same time, a development test bench for prototyping is established to develop traction control system. It consists of sensors, actuators, computer, I/O interface cards, conventional components of vehicle, etc. To validate the above-mentioned algorithm, hardware-in-the-loop tests and road tests on icy road and splited road are made. The results indicate that traction control system is able to receive signals exactly, create control command and drive actuators to eliminate excess slip of driving wheel.

Key words: Four wheel drive Traction control system, Hardware-in-the-loop Road test, Vehicle engineering