Research on Characteristics of Gecko’s Gait and Posture

Abstract

Gait is the correlation of the limbs in time and space, is the repetitional moving order -- lifting up and putting down. Gait is an important parameter on studying moving machine, such as its stability, cyclicity and operatability. Gait planning is one of fundamental parameters for bio-robot, which has a direct effect on the mechanics characteristics of the locomotive mechanism and the solution to control the motion of bio-robot. Posture is the shape of the body. Each action of the walking contains the gait realization and posture adjustment. So, it is very important to make a quantitative analysis on gait and posture for the biomimetic robot design. In nature, Gecko has an outstanding entire space moving ability. At present researches indicate that the structure of gecko’s foot is the foremost importance to its moving ability. At the same time, our research also discovers the gecko's gait is forceful guarantee to its agile motion.

The experiment takes the gekko gecko as research object and adopt the high speed camera (more than 1000 frames per second) to record the moving of the gecko, then save the series of image to the computer. Through a special software we can obtain data of the sign on the gecko, and then the characteristics of its motion.

The paper mainly focuses on Gecko’s lumbar spine and four limbs. Firstly, it makes a further research on Gecko’s gait and posture characteristics such as lateral bending when it walks in the linear passage (land, wall, ceiling) and the curving passage. Secondly, it defines the locomotion direction and turning angle for the Gecko turning process by the means of curve fitting. Finally, the result can be concluded as the following: the angle variation of legs can be repeated during the motion; In different surface, it is varied that the gecko gait such as the period in which each leg is landed in surface, the sequence in which each leg was whether lift in advance or not during the motion. The motion speed of gecko is changed by adjusting the duty factors of each leg on the same surface. The gecko gait isn’t varied at different motion speed on the same surface.

During its whole motion, its body locomotion includes two directions: lateral and longitudinal; and the body lateral bending period is the same as the gait period; the lateral bending magnitude is maximal in the middle of the body, minimal in the two ends of the body; each part of the body reaches the lateral bending peak at the different time; during the process of turning, the lateral bending magnitude is inverse proportional with the gait period and so on.