The UAV project has several milestones on the road to full automated
capabilities. The stages that have been identified so far:
Build the prototype
The LM-110 was identified as the prototype airframe. It took roughly thirty
hours to construct, including a long nap and waiting for the fuel proof
dope to dry.
Learn to fly under manual control
The project's chief test pilot is still learning to hover the prototype
with a standard RC helicopter control. Roughly two liters of nitro fuel
have been run through the engine and the aircraft is performing quite well.
A crash on 20 September 2001 broke the tailboom and tailrotor gear box,
as well as lost some of the tail rotor linkage. Replacements were
ordered. The tailboom and gearbox was repaired and some of the linkages
refabricated. It isn't pretty, but it flies again.
Manual control via computer
The first step towards computer control will be manual control via a laptop,
the SSC servo controller and visual observation of the prototype.
This might be easier than the the previous step since the computer control
can do control mixing and "hover throttle" settings that the manual
control does not. The helicopter was tethered to the
laptop rather than risking the embedded system at this point.
Manual control via computer with video feed
We are here. The xcam video unit has been fitted and the
aircraft balanced for the extra weight of the camera and sender
unit. A public demo was given in early October 2001. The prototype
was capable of taking off and hovering, despite the extra 100g of
Manual control via computer and EFIS
Once a low-cost AHRS system has been found and installed, the next
step is to learn to fly the prototype solely on the instruments.
Similar to flight in IMC, the helicopter's attitude will be controlled
by the test pilot who only views the EFIS screen. A spotter will
watch the helicopter to ensure that it does not cause any sort
of damage to persons or property. Again, the helicopter will likely
be tethered. A screen shot for the EFIS code is shown on the left.
Automatic control via computer
This is the next to last step towards the ultimate goal of the project.
Once the prototype is controllable via the EFIS, the control software can
start incrementally adding support. Tail rotor control is likely to be
the first extra functionality in a fashion similar to the "heading hold"
gyros. Then an automatic leveling function for the main rotor. Add a
sonar altimeter and be able to land or autorotate automatically.
And lastly a "position hold" feature that will combine all of the
stabilized functions to allow the UAV to stay in one location.
Implement mid scale aircraft
The stage two prototype is likely to be a commercially available airframe
of sufficient size to carry the onboard systems (computer, AHRS, GPS,
servo drivers, sensors, etc), but well short of the target payload.
(pictured on the right) from Bergen is a good candidate.
However, a Kyosho Concept 60 became available for the right price,
so it has been purchased. See the
for more details.
The command and control software should be fairly robust at this point,
so the joystick backup can be discarded. The ground station can be
collapsed to run entirely on a handheld computer, such as a Compaq iPAQ
with Linux and an 802.11 card.
Design and build large aircraft
Once the command and control software has been debugged on the prototype
airframe, the full size rotorcrft needs to be designed and built.
Much of the hardware from the prototype can be reused -- the servo
controller, the laptop ground station, and the AHRS. The design
of the larger airframe is an open problem and one that will require
input from potential users.
More ideas on the overall design