System und Verfahren zum Ermitteln der Geschwindigkeit eines allradgetriebenen Fahrzeugs

摘要

A vehicle speed calculation system capable of calculating a reference speed of a four-wheel drive vehicle with high accuracy even when a four-wheel slip or lock occurs. The system uses a wheel speed sensor for each wheel and a longitudinal acceleration sensor. The speed signals corresponding to the lowest and highest wheel speeds are selected and their variation per unit time is calculated. An integrated value of the longitudinal acceleration signal is forcedly used for the calculation of the reference speed when the vehicle is not braked and the variation of the lowest wheel speed is negative, or when the vehicle is braked and the variation of the highest wheel speed is positive. <IMAGE>