A Reconfigurable Leg for Walking Robots

We present the design of a robotic leg that can seamlessly switch between a spring-suspended, and unsuspended configuration. Switching is realized by a mechanism that exploits the alternative configuration of the two-link leg. The mechanism is lightweight, does not require additional actuation, and only relies on the leg movement for engagement. We validated the performance of the prototype leg on a single-leg testbed and investigated the power consumption during standing, crouching, and hopping in both configurations. The experiments showed that the efficiency of hopping and cyclic base height control is better with the spring-suspended configuration. However, it can undermine the leg’s performance in position control and requires higher torque to maintain low base height, where the unsuspended configuration has advantages. Overall, the switching ability allows for seamlessly selecting the optimal mode for a specific locomotion task.