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G-CUEING MICROCONTROLLER(A MICROPROCESSOR APPLICATION IN SIMULATORS)

Chris G. HorattasGoodyear Aerospace Corporation

Akron, Ohio

Digital Simulation of aircraft flight requires the iterative solution of a timeand event dependent mathematical model. Simulation realism is enhanced by highrate of solution. A simulation whose solution rate produces cues which are per-ceived to be the same as real-world cues, is considered a real-time simulation.Achieving real time simulation is a prime consideration in simulator design.

The computation system required to produce real-time simulation is either asingle, high cost, extremely high speed processor, or an array of less powerfulprocessors which share the computation task. When multiple processors are usedin such array, each is usually dedicated to a simulation subtask and must oper-ate synchronously with the other processors in the array.

One such dedicated processor is the G-Cueing Microcontroller (G-CM). The G-CMconsists of a tandem pair of microprocessors, dedicated to the task of simula-ting pilot sensed cues caused by gravity effects. This task includes executionof a g-cueing model which drives actuators that alter the configuration of thepilot's seat.

The G-Cueing Microcontroller receives acceleration commands from the aerodynam-ics model in the main computer and creates the stimuli that produce physicalacceleration effects of the aircraft seat on the pilots anatomy. One of thetwo microprocessors is a fixed instruction processor that performs all controland interface functions. The other, a specially designed bipolar bit-slicemicroprocessor with on-board hardware multiply and firmware implemented dividesquare root and sine functions, is a microprogrammable processor dedicated toall arithmetic operations. The two processors communicate with each other bya shared memory.

The G-Cueing Microcontroller contains its own dedicated I/O conve-rsion modules(analog-to-digital, and digital-to-analog) for interface with the seat actuatorsand controls, and a DMA controller for interfacing with the simulation computer.

Even though the microcontroller is programmed to perform the g-cueing model, itis not limited to this specific application. Any application which can be micro-coded within the available memory, the available real time and the available I/Ochannels, could be implemented in the same controller. Furthermore, the micro-controller capacity can be expanded by the addition of memory and I/O modules.

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https://ntrs.nasa.gov/search.jsp?R=19810003149 2018-04-28T20:29:45+00:00Z

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