Using FPGA and Real-Time Network Framework

In this paper, a scheme for a haptic communication system is proposed by using an FPGA (Field Programmable Gate Array) and real-time network framework, RTnet. In the haptic communication system, the FPGA is used as a motion control processor, and the Linux-based real-time network framework is applied to the communication line between a master and a slave robot. The FPGA can execute control calculations in a short interval. Sending a large number of packets in a short period is, however, not acceptable for the communication line. In the haptic communication system, the FPGA execute the control calculation in every 50 s, and the packets are sent in every 1 ms to prevent network congestion. The degrees-of-freedom(DOF) of the haptic device can be increased without increasing the number of sending packets, since the data of the each DOF is packed into one packet in a Linux module. In this paper, a master-slave haptic communication system is developed. The master side consists of a haptic device, whereas the slave side consists of a virtual haptic device and a virtual environment. The validity of the haptic communication system is shown through an experiment.