Coordination of monopedal SLIP models towards quadrupedal running

Abstract

This paper presents a coordination controller for the Dual-SLIP model, a novel template for quadrupedal steady and transitional running. The model consists of a pair of “physically-unconnected” Spring-Loaded Inverted Pendulums (SLIPs), each representing a part of the body of a quadruped (see Figure 1). For this model, we propose a spatio-temporal coordination controller that describes the evolution of coordination parameters by simple difference equations. A “time-aware” deadbeat low-level controller is also proposed to realizing the generated control specifications in each SLIP individually. Evaluation of the proposed coordination controller for the Dual-SLIP model in simulation shows that even with remarkably off-phase initial conditions and ground height variation disturbances, quadrupedal bounding, pronking and different transitions between them can be realized.