Effects of joint compliance in quadrupedal locomotion

Compliance is one of the most pronounced characteristics in animals. It is present in almost all parts of the musculoskeletal system of a body: muscles, tendons, tissue, skin and even bones all possess a certain level of compliance. The effects of compliance greatly vary on the momentary task or activity. It has the potential to add robustness to stiff/brittle structures, is able to store and release energy and can help to reduce peak forces e.g. when an impact is experienced. In order to profit from such properties, it is important to note that in most cases the compliance needs to be welltuned to obtain a desired effect. In locomotion, compliance is suspected to play a key-role in many aspects from safety and gait stabilization to energy efficiency and dynamic gaits (e.g. [1]), given that the compliance suits a specific mode and gait. It is unclear however, which kind of compliance acts on which aspects and how to quantify potential benefits. Our aim in this work is the development of a robotic platform in the shape of a compliant modular quadruped robot that is able to measure a variety of intrinsic and extrinsic variables to get insight into divers locomotion parameters. The platform is relatively low-budget by mainly using off-the-shelf components, highly customizable and fast to reconfigure due to its modular nature. This allows to rapidly perform experiments on different morphologies with variable structural and compliance properties.