ECU controlled intelligent lift axle dropping and lifting system for heavy trucks

This paper reports the design and control of an automatic lift axle auto-drop system that is normally controlled manually by the driver. The goal of the automatic lift axle dropping system is to drop or lower one or more of the liftable axles of the truck automatically, based on loading and other conditions. In this paper, the experimental implementation of an AutoDrop system in a truck suspended with a compensating arm type mechanical suspension is presented. Axle weight estimation for a compensating arm type suspension has challenges because of the articulated nature of the suspension mechanism and the presence of a large hysteresis characteristic. This paper introduces an analysis and higher accuracy height sensor based estimation method for weight determination in axles with a compensating arm suspension. An improved algorithm is developed and the lift axle system operation is automated to satisfy the rules mentioned in EU Directive 1230/2012 EEC. The developed algorithm is coded and implemented using an electronic control unit mounted in the vehicle cabin. Experimental results are used to demonstrate the successful implementation of the developed algorithm.