[ExI] flying cars?

[Keith Henson]

On Fri, Jun 24, 2011 at 10:31 PM, spike <spike66 at att.net> wrote:
>
>
> -----Original Message-----
> From: extropy-chat-bounces at lists.extropy.org
> [mailto:extropy-chat-bounces at lists.extropy.org] On Behalf Of Keith Henson
> Subject: Re: [ExI] flying cars?
>
> On Fri, Jun 24, 2011 at 7:31 AM, spike <spike66 at att.net> wrote:
>
> snip
>>
>>> Hi Keith, this is cool, but...  What he has there I think is actually
> strictly a hovercraft.
>
>>Could be.  But what I think is likely or if not in this case shortly is the
> application of a lot of computation to control.
>
>>You can see that in those little electric quad and hex helicopters.  Keith
>
>
> Ja, I can imagine something like this in freeflight with four rotors in a
> cruciform configuration.  With only the two and only thrust vector control,
> you can almost see the instability in any flight regime out of ground
> effect.  A gust of wind or any perturbation, over it goes in a roll,
> entering a mode which thrust vectoring provides insufficient control
> authority to recover, even if you assume perfect compensation.  We had a
> saying for that.  With some flight configurations, it was said this craft
> could not be stabilized even with god at the controls.

It seems to me from the pictures that there are a quad of thrust
elements, one on each corner.

Keith