Design of an open-source low cost 2DOF haptic device

The paper describes the design and preliminary virtual testing of OSHap, an open-source low cost 2DOF haptic interface. The aim the research is to create a mechatronic platform for haptic interaction based mainly on cheap and open source components. The results will be distributed freely in order to provide guidelines for expert users to develop their own haptic interface. Both the mechanical design philosophy and the control electronics are hereby discussed together with a preliminary testing made by using virtual prototyping tools. The kinematic layout is based on a serial double joint scheme. This choice is claimed to be the less expensive one, inasmuch as tolerances do not have to be narrow as for the parallel systems. The system also allows future users to tune dimensions (and relative workspace) easily. The interface is admittance controlled for maximizing the transparency with low cost drives. The device is based on the Intel Galileo open-source development board: this board embeds a powerful chip-sets that enables us to perform real-time 2DOF control tasks that are hardly reachable with the most common open source electronic platforms. All the choices listed above are discussed and evaluated, with focus on performance-to-cost ratio.