Design considerations for stand-alone haptic interfaces communicating via UDP protocol

This work was motivated by the need for high speed communication between a stand-alone haptic interface and a computer running haptic rendering algorithms. This paper describes our recent work on the use of User Datagram Protocol (UDP) over Ethernet as a communication channel between a remote computer and a custom embedded controller built for a 3 DOF force-feedback haptic interface (the 3-DOF ministick). The results and observations from three experiments designed to test the use of detailed timing diagrams representing theoretical models are contrasted with experimental data in order to isolate potential problems and verify predicted models. Details of the hardware that enabled a haptic update rate of 3800 Hz are presented. Important information learned through the testing process is presented to the reader in order to help reduce development time for other systems in which Ethernet is desired as a communication channel.