Energetics of bio-inspired legged robot locomotion with elastically-suspended loads

Elasticity is an essential property of locomotion. In biology, elastically-suspended loads increase the efficiency of locomotion and load carrying. Similarly, elastically-suspended loads have the potential to increase the energy efficiency of legged robot locomotion. External loads and the inherent mass of a legged robot, such as batteries, electronics, and fuel, can be elastically-suspended from the robot with compliant springs, passively reducing the energetic cost of locomotion. An experimental prototype hexapod robot with a novel elastic load suspension mechanism based on the Christie suspension system is developed and utilized to test the energy efficiency of legged robot locomotion with elastically-suspended loads versus rigidly-attached loads. Elastically-suspended loads are shown to reduce the energetic cost of locomotion compared to rigidly-attached loads. Thus, the speed, operation time, or load carrying capacity could be increased for robots that utilize elastically-suspended loads.