The reason for large yaw is to avoid fast washout, which results in parasitic forces that destroy the illusion. We actually tend to raise the real:simulated yaw ratio by quite a bit.

Still, there’s no evidence we’ve run into that suggests that 1:1 yaw is unrealistic. There can be external elements that cause problems – seeing objects ‘moving around’ outside the displays, for one, or failure of the rotation axis to adequately match transients in the simulation output, for another. But if you deal with those, there’s no reason to pull back the yaw ratio.

There are also more elements than the inner ear involved in the yaw feel – the loading on your shoulders and body in general changes as well. You have to take all these things into account.

We did a lot of testing with various yaw setups, and came to the conclusion that having more range is better for a few reasons:

1) Larger range is important not because big rotations are big, but because small rotations are perceptible. With a +/- 15 degree yaw range, 1 degree changes in vehicle angle are imperceptible unless you apply nonlinear scaling or apply very fast washouts, which get extremely difficult to handle correctly and are *always* suboptimal. The ability to provide subtle rotation cues without intrusive washout is *ABSOLUTELY CRITICAL* to feel. I can’t emphasize that enough!

2) You can deal with fast, large rotations if you set the center of rotation correctly. Put it too far back and you feel like you’re driving an office chair; too far forward and you feel like you’re on the end of a rope.

3) Washout, as mentioned before. Even at the same ratio – say, 10 degrees of simulated yaw to 1 degree of physical output yaw – a wide rotation range allows slower washout and fewer parasitic forces; your brain doesn’t think your car is rotating to the left immediately after you exit a right hand corner and start heading down the straight.

As far as carnival rides go – our customers use our machines in many different arenas, and some are intentionally aiming for the ‘carnival ride’ type experience.

Cuing setup and software have a massive impact on perceived simulator performance, so for anyone out there who’s done a 5-minute run in one of our machines and said, “This is ludicrous!”, keep in mind that the operators may have set them up to draw a crowd or leave riders weak-kneed, rather than provide the most realistic possible experience.

I think that in general we’ve got a pretty competitive setup vs. Cruden. They’ve got a proprietary system that gives them a better force feedback steering, and the size of the platforms gives them the ability to have larger payloads, but we have much lower power requirements, easy setup, easy transport and much smaller size, more flexible and open software support, equivalent or better roll/pitch/z performance and much better yaw performance, better transient and high frequency response – and a one hell of a lot smaller price tag!