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Engineers and pilots have always evaluated simulators subjectively. In the future, the flight simulation industry is apt to take a more deterministic, or objective, approach to evaluating simulators and take the subjectivity out of the validation process. The goal will be to provide the same performance across all simulators while making the qualification process more efficient.

Moog's linear control loader

How motion cueing is evaluated will be critical to achieving this goal. Motion cueing uses the pilots’ senses (sight, sound, and haptics) to make them believe they are moving, turning, and accelerating more than they actually are. For example, simulators recreate many of the effects of take-off and climb even though the simulator does not accelerate to 200 mph or ever climb higher than the stroke of the actuator.

By tuning a simulator to execute cueing algorithms that mimic sensations in actual flight, the industry will better prepare pilots to fly before they ever leave the ground.

The Moog G-seat

Motion simulators cannot recreate the sustained accelerations felt by fighter pilots. So for training, military-aircraft pilots strap into a Moog G-seat installed in the cockpit section of the simulator. The “cockpit” is wheeled into a spherical multiscreen display, much like a smaller version of an IMAX theater. While the cockpit does not move, the pilot’s controls (stick, throttle, and rudder) are hooked to the computer generating the graphics on the inside of the dome, which provides visual cues of the aircraft’s movements.

Moog's G-seat

The motion or physical cues come from small electric actuators invisibly mounted in the seat bucket, seat pan, and back pad. These actuators push or pull on the pilot at up to 100 mm/sec for distances of up to ±25 mm, and recreate accelerations of up to 1,200 mm/sec2. The shoulder and lap belts are also hooked into tensioning mechanisms that add to the realism. For example on take-off, the seat back pushes out, and the lap and shoulder belts tighten, making pilots feel as if they are accelerating.

For more realism, harness and leg straps can be controlled and an additional actuator in the seat pan replicates rolling options. The G-seat can replicate positive and negative gs by changing the shape of the seat pan, raising or lowering the seat bucket, and altering tension on the harness. This closely recreates conditions pilots encounter in dogfights and bombing runs such as stall buffet and weapons release.

The seat looks like a standard ejection seat found in tactical military aircraft. But there is also a version specifically for simulating helicopter flight where vibrations from the blades are critical cues.

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This file type includes high resolution graphics and schematics when applicable.