Rolling SLIP model based running on a hexapod robot

We report on development of dynamic running behavior on the RHex-style hexapod robot. By using the Rolling SLIP (R-SLIP) model as the “template” of the robot, together with the investigation of the stability properties of the R-SLIP model, the robot implemented with the selected trajectory based on the R-SLIP motion can immediately excite its dynamic running behavior (i.e., composed of stance and flight phases) without necessity of extra tuning or optimization effort. In addition, a feedback control strategy is proposed to regulate the robot´s motion when the robot´s operating region is not located at the stable area of the R-SLIP model (i.e., no stable fixed point). The controller includes three portions: a body velocity estimator, a database containing a wide range of pre-computed R-SLIP trajectories, and a control law which regulates the robot motion to the desired R-SLIP profile. The proposed methodology of robot trajectory generation and strategy of running regulation are experimentally evaluated.