On the Backward Hopping Problem of Legged Robots

When realizing jumping locomotion on legged robots, trajectories that are generated without assessing angular momentum information are found to be prone to backward hopping motions, due to the undesired body rotations developed during the support phase, prior to liftoff. In this letter, we succinctly discuss the underlying characteristics of such an undesired motion and propose a possible solution that is based on our previous work. In order to validate our claims, we conducted vertical jumping experiments on the actual bipedal robot MARI-3. As the result, the robot is able to exhibit dynamically balanced jumping motions without any backward hopping motion.