An Integrated, Modular Simulation System for Education ... - Cal Poly

card and sends commands from the PC s D/A card through an amplifier to the sick andrudder pedal torque motors. The amount of torque generated by the motors can be setstatically through the stick computers front panel or by varying the reference voltagesfrom the PC to the stick computer. The stick computer also sends back to the IO (PC)computer stick position, force, and trim position and velocity. Feeding back force to theposition, virtual spring and damping can be created. By feeding back force and dampingproportional to any of the modeled states can be used to enhance the handling qualities ofan aircraft [Ref. 25].PhEagle Hardware - ComputersThe heart of the simulation lab is the computer network. There are 4 Pentium 166MHz computers connected by Ethernet to provide the simulation dynamics, highresolution texture mapped graphics and, input-output (IO) to the simulation cab. Byseparating the simulation tasks to processes that are only dependant on input once eachintegration time step or once every several time steps, a flexible computing environmentusing as many or as few computers as are required for each simulation is possible. Sincethe information is sent over a network the machine acting as the master controlling thesimulation could be any computer. Substituting a Unix workstation for a PC calculatingthe equations of motion for a complex simulation such as a helicopter blade elementmodel running in real time would be seamless.Low-cost PC sSince each task in the system is performed on a separate PC with little specialhardware, upgrades to the system can be made incrementally, spreading the cost ofhardware upgrades over as much time as is required. Slower machines can be quickly set15