Dimitri: an Open-Source Humanoid Robot with Compliant Joint

We introduce Dimitri, an open-software & open-hardware humanoid robot with 31 DOFs, fitted with cost-effective modular compliant joints and parallel link legs, designed for advanced human-robot interaction research, force-informed object handling and intelligent environment discovery. Our main innovation is in the design of a robust full-body biped humanoid robot equipped with very low-cost polyurethane torsional spring fixed to traditional servo motors and a circuit to measure angular displacement, transforming the system into a series elastic actuator (SEA). In order to illustrate the robot's qualities in the field of machine learning applied to robotics and manipulation, a multiple timescale recurrent neural network (MTRNN) is implemented, allowing the robot to replicate combined movement sequences earlier taught via interactive demonstration.