Serpens, A Low-Cost Snake Robot with Series Elastic Torque-Controlled Actuators and A Screw-Less Assembly Mechanism

Even though a few examples of elastic snake robots exist, they are generally expensive and tailored to custom-made hardware/software components that are not openly available. In this work, Serpens, a newly-designed low-cost, open-source and highly-compliant modular snake robot with series elastic actuators (SEA) is presented. Serpens features precision torque control and stereoscopic vision. Only low-cost commercial-off-the-shelf (COTS) components are adopted. The robot modules can be 3D-printed by using Fused Deposition Modelling (FDM) manufacturing technology, thus making the rapid-prototyping process very economical and fast. A screw-less assembly mechanism allows for connecting the modules and reconfiguring the robot in a reliable and robust manner. By using a low-cost sensing approach, functions for torque sensing at the joint level, sensitive collision detection and joint compliant control are possible. The concept of modularity is also applied to the system architecture on both the software and hardware sides. The software architecture is based on the Robot Operating System (ROS). This paper describes the design of Serpens and presents preliminary simulation and experimental results which illustrate its potential.