Cost of locomotion of a dynamic hexapedal robot

In this work we analyze the cost of transport of in-plane hexapedal robots. The robots are modeled as a rigid body with six massless legs, each having two compliant degrees of freedom and the contact is modeled using Coulomb´s model. We start our analysis by formulating the cost of transport for rigid legged robots as a function of their geometry, friction coefficients, actuation velocities and slope angle and compare it to the results of a dynamic multibody numeric simulation. In the second part, we estimate the cost of transport in the more general case when the legs and surface are compliant. We evaluate the energy consumptions factors, sliding, work against gravity, elastic losses of the legs and the surface, and kinetic energy and compare them to the total energy input of the actuators. This analysis allows us to evaluate the work range of the robots and determine the optimum locomotion paths for improved battery performance.