Efficiency Optimisation of a Forestry Crane by Implement Hydraulics with Energy Recovery

Forwarders are an essential part in fully mechanised timber harvesting chains. Due to a suboptimal energy usage at the implement hydraulics, caused by unused energy recovery, there is a great potential for an optimisation of the machines to increase its sustainability and environmental compatibility. Hence, innovative solutions for this challenge are designed within the project ‘Forwarder2020’ at the Karlsruhe Institute of Technology (KIT), embedded in and sponsored by the European program ‘Horizon 2020’, managed by the project leader HSM Hohenloher Spezial-Maschinenbau GmbH & Co. KG. The focus in this treatise is on the energy efficiency of a forestry crane, for example mounted on a forwarder. On current machines there is no built-in system to recover energy. An energy recuperation and regeneration system is therefore developed for forestry cranes. To compare the efficiency of different machines or system architectures and to evaluate the energy recovery potential of loading processes, reference loading cycles have been established based on field measurements of real logging processes. These standardized reference cycles represent recurrent loading cycles in a working environment.