Box 118, SE-22100 Lund, Sweden; Zan.wu@energy.lth.se 3 State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou 310027, China * Correspondence: bengt.sunden@energy.lth.se; Tel.: +86-0571-87951216 Received: 3 September 2019; Accepted: 16 October 2019; ...