Stability of a trotting quadruped robot with passive, underactuated legs

A 2-D dynamic simulation of a quadruped robot with passive, directionally compliant legs has shown that with the proper leg configuration, increased stability of the robot can be achieved passively. Increased stability is defined as decreased pitching motion of the robot. A limited search of the design space of the legs resulted in the finding the leg parameters that minimized the pitching. Steady state trotting, changing speeds, and disturbances such as steps and holes were tested.