An analytical estimation of the energy cost for legged locomotion

Abstract

Legged locomotion requires the determination of a number of parameters such as stride period, stride length, order of leg movements, leg trajectory, etc. How are these parameters determined? It has been reported that the locomotor patterns of many legged animals exhibit common characteristics, which suggests that there exists a basic strategy for legged locomotion. In this study we derive an equation to estimate the cost of transport for legged locomotion and examine a criterion of the minimization of the transport cost as a candidate of the strategy. The obtained optimal locomotor pattern that minimizes the cost suitably represents many characteristics of the pattern observed in legged animals. This suggests that the locomotor pattern of legged animals is well optimized with regard to the energetic cost. The result also suggests that the existence of specific gait patterns and the phase transition between them could be the result due to optimization; they are induced by the change in the distribution of ground reaction forces for each leg during locomotion.

Evolution of archosaurian body plans: skeletal adaptations of an air‐sac‐based breathing apparatus in birds and other archosaurs

“…However, given the exceptional skeletal evidence for a heterogeneously partitioned pulmonary apparatus in saurischian dinosaurs and pterosaurs, it is important to note that such pulmonary systems in extant sauropsids also occupy a significant volume of the body cavity (see Duncker,'79;Perry,'83;Duncker and Güntert,'85). Thus, whole body mass estimates in fossil archosaurs (e.g., Wedel, 2005Wedel, , 2007Schwarz and Fritchs, 2006) and any associated energetic considerations for whole body mechanics (e.g., turning inertia [Carrier et al, 2001], cost of transport [Nishii, 2006]) or thermoregulation (Perry et al, this volume) must account for those portions of the anatomy (e.g., intrathoracic and intraabdominal air sacs) not predicted to directly impact skeletal morphology in preserved fossils of these taxa. For example, recent modeling efforts (Hutchinson et al, 2007) have explicitly attempted to model locomotor biology in extinct archosaurs using a range of estimates for whole trunk density based on different models of pulmonary structure.…”

Constraint and exploitation of redundant degrees of freedom during walking

“…Many experimental and theoretical studies have reported that locomotor parameters, such as stride length and frequency, are optimized based on energy cost [2,3,4,5,6,7]. However, the choice of leg swing trajectory during walking is still under debate.…”

Soft computing-based approaches to predict energy consumption and stability margin of six-legged robots moving on gradient terrains

“…The first term represents mechanical energy and the second term is related to energy loss by heat emissions. Although a negative value for the first term, i.e., mechanical energy indicates a gain in energy supplied by external forces, DC motor cannot store this energy [20,21]. Therefore, the energy consumed by the DC motor during time T is given by…”