Reach stackers are heavy duty mobile machines mainly used for container handling on intermodal terminals or harbors. The increasingly restrictive legislation on pollutant emissions as well as the need to reduce fuel costs for operators motivate manufacturers to design more efficient machines. Previous studies highlighted three ways to improve the fuel consumption, namely: (i) improving the engine efficiency; (ii) recuperating the potential energy of elevated containers; (iii) recovering the kinetic energy of the vehicle during decelerations. The architecture proposed in this paper combines these three requirements while preserving most of the conventional components. It results in a moderately priced solution. Control strategies are also studied, especially focusing on the potential energy recovery system where an input-output linearization method is compared to a conventional linear controller. Simulation conducted on several duty cycles shows fuel savings of up to 18.4% and a good robustness to cycle variations.

This study focuses on the global energy flow analysis along the three main energy lines of an off-highway vehicle used on port areas called a reach stacker. In order to characterize the energy consumption of the power train and the actuation system, a model of the machine has been established using the bond graph methodology. This language is suitable for representing multi domains energy transfers and allows the determination of the needed energy for an actuator to perform a given task. The simulation results are then compared with measurements carried out on a real reach stacker. Those data help to identify several parameters like friction coefficients and efficiencies. The energy flow analysis also gives detailed information on the main energy losses sources which prefigures coming evolutions.