HyQ - A Dynamic Locomotion Research Platform

Articulated robots such as legged robots hold the promise to lead to versatile, multi purpose machines that eventually become useful in many application scenarios such as construction sites, disaster recovery, service robotics and remote inspection. For these tasks a great deal of kinematic flexibility and dexterity is required. As the inspiring examples in biology show, arms and legs are useful both for manipulation and locomotion. Legs become very advantageous for highly dynamic locomotion in severely challenging terrain, i.e. terrain where wheeled and legged system of comparable size cannot go. This fact is easily appreciated by observing cats going about their daily lives, or mountain goats effortlessly bounding up steep rock faces. While this superior all-terrain agility is typically the motivation behind research in legged robots, actual results on robust and versatile all-terrain locomotion are not abundant. To achieve such locomotion, dynamic legged machines with torque controlled joints are required, but they are not available. Active compliance via torque control would allow the implementation of a big range of all-terrain locomotion controllers. Furthermore, such machines would enable the experimental verification of bio-mechanical hypotheses including animal locomotion models, such as the influence of muscle models or spring-mass models. The latter is often used to describe bouncing gaits (running, hopping, trotting, galloping) in animal and human locomotion and robotics [1], [2]. Experimentally obtained data allow the comparison of various gaits and speeds, and have the potential to provide a deeper understanding of animal locomotion, which animal studies using force plates and motion capture systems cannot provide.