Walking Robot Scorpion - Experiences with a Full Parametric Model

Abstract

A set of about 70 variables controls geometry, kinematics and dynamics of the eight legged robot model. Changes in design or in physical parameters can be incorporated immediately. General motion patterns of adult scorpions (Hadru- rus arizonensis) are parameterized and implemented. A closer analysis of the data leads to an analytical model for smooth speed transitions while the full coordination is preserved among the legs. A new interpretation of the data suggests a constant stride length throughout the full range of speed from slow walking to very fast running. These aspects of the biological original lead to simplifications in the motion control of the robot. A small set of variables is sufficient for accelerated forward motion. A mathematical solution is presented for an optimal joint coordination of a leg during stance. Basic experiments lead to suggestions regarding motion patterns, stability and efficiency. First simulations show interesting aspects during an accelerated running. The results are discussed with reference to consequences and considerations for the walking robot Scorpion.