Locomotion studies and modeling of the long-tailed lizard Takydromus sexlineatus

Morphology is an important factor in locomotion. It may guide the control strategies that an animal or a robot uses for efficient locomotion. In this paper we try to understand the locomotion strategies of a lizard with a distinctive feature, the long-tailed lizard Takydromus sexlineatus. We recorded the performance of real animals in terms of forward speed and then developed a simulation model respecting the morphometric characteristics of long-tailed lizards. We then run systematic tests altering several control parameters of the model. The simulation experiments suggested possible control strategies for effective locomotion given this type of morphology. The experiments were not constrained or guided by any prior knowledge on specific animal angular kinematics. Therefore, the good match between the suggested kinematics for optimal speed and the kinematics of the real animal suggests that our framework is capable of exploring in the future the effects of morphosis on the locomotion strategies of animals, e.g. to perform the same study with shorter or no tail.