[Canberrauav] Car - arrived

Chris Gough christopher.d.gough at gmail.com
Thu Nov 29 16:02:38 EST 2012


<random idea>
The UGV equipped with a 4-arm UAV cradle.
The arms are made of pipe, joined to form a single manifold, with
suction cups on the 4 open ends plus some  gadegtry plumbed into the
middle.

Gadgetry:
 * 12v vacuum pump, e.g. [1] $15
 * 3-way electronic way vacuum valve, e.g. [2] $12
 * vacuum sensor, e.g. MPX5050GP $23
 * some sort of microcontroller... :)

[1] https://www.sparkfun.com/products/10398
[2] http://www.ebay.com.au/itm/350635011526?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

def secure_wing():
    valve.select(MANIFOLD)
    pump.draw_vacuum(VACUUMS_PRESSURE)

def release_wing():
    valve.select(ATMOSPHERE)
    pump.draw_vacuum(None)

The only "attachment" on airframe would be smooth surface (perfectly
simple mechanism). The cradle would be simple to build and easy to
modify. Mechanical funkyness is hidden in cheap generic parts.

<crazy-talk>
We could directly measure the lift produced by the UAV during launch
(up to the weight of the UGV).


from wikipedia import physics
def estimate_lift():
    return physics.atmospheric_force(
        manifold.pressure() - VACUUM_PRESSURE,
        SUCKTION_CUP_AREA
    )
def launch_impulse():
    return physics.unweight_impulse(
        TARGET_CLIMB_ANGLE,
        UAV_WEIGHT
    )
while estimate_lift() - target_climb_lift() < 0:
    keep_accelerating()
release_wing()

</crazy talk>

<crazy talk>
...With remotely adjustable AoA, we could drive around sampling
lift at AoA@airspeed then estimate the airframes lift polar (crude wind
tunnel, in ground effect).
</crazy talk>

With some mechanical trickery in the manifold (hose, springs, bearings
etc), the arms could be made to tuck away when the suction cups
release, so it could drive to the pits in robot bagpipe darlek style.
Tartan or silver?
</random idea>

Chris Gough

P.S. Variant: the airframe could control the release, i.e. valve like
[3] and a pressure reservoir in the airframe. The vacuum circuit and
pressure vessel could be pre-charged on the ground, and the UGV would
just have a passive cradle with blank suction cups

[3] http://www.hobbyking.com/hobbyking/store/__8361__Air_Operated_Switch_3_way_supply_.html,
~$6

With another pressure vessel, valve and a vacuum reservoir, we could
use a similar mechanism to release the payload. Very slick!


On Wed, Nov 28, 2012 at 8:49 PM, Stephen Dade <stephen_dade at hotmail.com> wrote:
> Hi everyone,
>
>
>
> After a (short) wait of 3 days, I now have the Turnigy 4WD Truck sitting in
> my house.
>
>
>
> The good news is that the ESC has XT60 connectors. All we need is a tx/rx
> and a battery and we should be good to go.
>
>
>
> I’ll scavenge the rx from my quadcopter and run some trials on Friday
> evening.
>
>
>
> In the meantime, I’ll grab the turnigy 6x transmitter and a few rx’s (and
> some spare parts) from hobbyking as a more permanent solution.
>
>
>
>
>
>
>
> Thanks
>
>
>
> Stephen
>
>
> _______________________________________________
> Canberrauav mailing list
> Canberrauav at canberrauav.com
> http://www.canberrauav.com/mailman/listinfo/canberrauav
>



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