Investigations on energy optimal solutions to control a forestry crane

Due to the progressing climate change, climate-neutral resources are becoming increasingly important. The forest industry is aware of this problem and hence, is looking for new technologies to make the production of its natural resource more ecient. Therefore, this thesis presents an energetic optimization of a forestry crane. For this purpose, a pseudoinverse solution of the crane kinematics is optimized by the gradient projection method according to minimum hydraulic pressure and ow rate. The hydraulic pressure reveals to be the relevant optimization parameter. By increasing the feedback pressure, its inuence on high-pressure peaks is increased in order to successfully reduce these. To maximize the energy savings, a hydraulic transformer is included in this approach. By coupling the inner and outer boom, potential energy is utilized for contrary motions of these. The developed algorithm for optimizing the energy demand is implemented in a holistic simulation model of a forestry crane arm. The eectiveness of this approach is tested in the model using representative trajectories. Energy savings of up to 26.9 % compared to a least norm pseudoinverse solution can be determined using the optimized control system. When the energy-saving potential of the coupling of the inner and outer boom is also considered, the total reduction in energy increases to up to 31.8 %.