Jaakim Lastunen

Hydraulic systems are widely used in NRMMs due to their high force generation potential for their size. They are, however, notoriously inefficient. The adoption of battery-electric mobile machines underlines the importance of more energy efficient actuation methods as the energy storage density of batteries is much lower than conventional diesel powertrains. The electrification of mobile machines also allows for novel hydraulic power transfer concepts that were previously infeasible.

The aim of my research is to develop a novel energy-efficient hydraulic actuation concept suitable for use in hybrid and electric non-road mobile machines (NRMM). The efficacy of the concept both in terms of energy saving potential and performance in key NRMM applications will be evaluated and verified with both simulations and experimental testing.

As a result of the research, a novel electro-hydraulic actuator (EHA) system with a multi-pressure booster is developed and validated. Its energy saving potential is verified with simulations as well as experimentally. The goal of the actuator concept is to attain energy efficiencies on par with or better than existing EHA concepts while reducing the torque demand, and thus physical size, of the prime mover. Consideration will be given to the performance of the actuator in hybrid and electric NRMM applications most suited for the system, such as the boom hydraulics of a forestry harvester or forwarder and the bucket hydraulics of a mining load-haul-dump machine.