Design and prototyping of a low-cost light weight fixed-endpoint orientation planar Cobot

Abstract

Here we present the design and construction of a low-cost planar robotic arm that makes use of light weight component and a passive link mechanism to maintain fixed endpoint orientation. The arm structure itself is low-cost and built from carbon fiber tubes which yields a high stiffness to weight ratio. To facilitate construction, commercially available pulley and bearing components are used in the design where possible and all custom mechanical parts are 3D printed. To reduce power consumption, the arm makes use of non-back-drivable worm-gear motor actuation, so static arm configurations can be maintained without requiring motor power. We first analyze and simulate the kinematics and the static torque/force relationships of the mechanism. A microcontroller system was then developed to read the sensors and drive the arm motors. Finally, we demonstrate arm operation with simple movement tasks.