College of Energy Engineering Zhejiang University Hangzhou 310058 China;
Zhejiang Zhixin Technology Co. Ltd Shaoxing 312000 China;
College of Energy Engineering Zhejiang University Hangzhou 310058 China;
Ocean College Zhejiang University Zhoushan 310021 China;
College of Energy Engineering Zhejiang University Hangzhou 310058 China;
The State Key Labora-tory of Fluid PowerTransmission and Control Hangzhou 310058 China;