Energy efficient fluid power in autonomous legged robotics based on bionic multi-stage energy supply

摘要

To improve the efficiency of hydraulic system of legged robot, a particular driving system is presented in this paper by imitating the multi-stage energy supplement from biological creatures. With respect to this design, it comes up with a double-stage energy supply system (DSS) using small accumulators. The DSS is a composition of a low-pressure variable pump and some other distributed instantaneous high power sources. The former provides energy for most continuous works under low pressure, while the latter is established to satisfy instant high-pressur demands by accumulators. DSS is able to achieve smaller energy loss than the energy supply system in which single-stage energy supply system (SSS) is used. The principle of DSS is described and DSS is analyzed for low energy loss. The DSS was applied in a quadruped robot as an example, and the efficiencies were calculated and compared with that of SSS when the robot makes squats, turns, and trots. Finally, some other performances were compared between DSS and SSS. The result shows that the efficiency is higher but the trim control is more difficult for DSS than SSS.