The use of compliant joints and elastic energy storage in bio-inspired legged robots

The green leafhopper,Cicadella viridis(Hemiptera, Auchenorrhyncha, Cicadellidae), jumps with near-constant acceleration

“…If compared with the jump of P. spumarius (Burrows, 2003;Burrows, 2007b), the C. viridis jump is slower (4.7 and 0.9ms -1 , respectively), but in contrast, it is cheaper in terms of energy consumption, by as much as 33% ( Burrows, 2007b). The fact that the insect adopts this strategy is of further interest when considering that jumping with constant thrust force is very close to the optimum strategy (Scarfogliero et al, 2009). Constant acceleration, and hence constant force, which minimizes stress in the legs and soil (Scarfogliero et al, 2009), could be considered as another solution to reduce possible breakage of the structures involved, from the legs to any surface used for take-off.…”

“…It was highlighted that a motion -such as that of C. viridis during the take-off phase of the jump -with a constant force at the foot-ground interface minimizes stresses both in the legs and the substrate for a given take-off speed, representing a behaviour close to the theoretical optimum (Scarfogliero et al, 2009). This suggests that the morphology of C. viridis legs, and their displacement with respect to G c , is responsible for the conversion of a musculo-elastic action into a constant force at the feet.…”

“…The fact that the insect adopts this strategy is of further interest when considering that jumping with constant thrust force is very close to the optimum strategy (Scarfogliero et al, 2009). Constant acceleration, and hence constant force, which minimizes stress in the legs and soil (Scarfogliero et al, 2009), could be considered as another solution to reduce possible breakage of the structures involved, from the legs to any surface used for take-off. In terms of escaping efficiency, this mechanism could ensure more successful jumps and a greater capacity for survival over different substrates.…”

“…In many cases insects have also developed mechanisms to store the energy produced by slow muscle contraction before the jump and to release it quickly, similarly to a loaded spring. To date, jumping locomotion has been studied to understand kinematics, neural mechanisms, energy cost and scale effects (Alexander, 1995;Biewener and Blickhan, 1988;Scholz et al, 2006), but also to extract bio-mimetic principles to develop robotic platforms, which could use these mechanisms to move in unstructured and uneven terrains (Cham et al, 2004;Scarfogliero et al, 2009). The jumping strategy of insects has been studied by means of high-speed video recordings and anatomical or physiological observations (Bennet-Clark and Lucey, 1967;Brackenbury and Wang, 1995;Burrows and Morris, 2003;Burrows, 2006).…”

Bio-inspired vertebral column, compliance and semi-passive dynamics in a lightweight humanoid robot

“…Rollin Justin Arms [10], ECCE Robot [15], robots of the PHRIENDS project [1], [4], [12]) and especially material compliance (see e.g. RHex [32] or [11], [34] [8], [17]). Besides, compliance is also essential in the design of leg prosthesis (see e.g.…”