1. Fluid Power and Mechatronic Systems, Department of Energy Technology, Aalborg University, Aalborg East, 9220, Denmark e-mail:
2. Professor Fluid Power and Mechatronic Systems, Department of Energy Technology, Aalborg University, Aalborg East, 9220, Denmark e-mail:
3. Associate Professor Fluid Power and Mechatronic Systems, Department of Energy Technology, Aalborg University, Aalborg East, 9220, Denmark e-mail: