Mercedes-Benz 4MATIC, an Electronically Controlled Four-Wheel Drive System for Improved Active Safety

Daimler-Benz have developed an automatically/electronically controlled traction system, the 4MATIC. Great store has been set by active safety. This paper deals with the problems involved in 4-Wheel drive and analyzes the reasons which led to the 4MATIC concept. Depending on the conditions encountered, the drive components engage automatically one after the other in the sequence front-wheel drive - interaxle differential lock - rear axle differential lock. The engagement, and thus the approaching limits of driving dynamics, is indicated to the driver by an indicator lamp so that he can adjust to the deteriorated conditions in time. A further important advantage of this system is the automatic disengagement of the differential locks when braking so that the anti-lock braking remains fully effective.