Outback Challenge Deliverable 2 Submitted

So there have been some sleepless nights recently as the deadline for the Outback Challenge second deliverable passed this afternoon.  I managed to get my report in by the skin of my teeth after some email troubles (still waiting on the confirmation from the organisers :S ).

Each team had to submit a technical report that details the design of their aircraft and their risk management strategies.  We also had to compile a video that demonstrates our on field setup procedure, takeoff and landing and how the aircraft handles carrying and dropping the payload. (more…)

Pulsar 4E Bottle Drop Tests

With the second deliverable for the Outback Challenge quickly approaching it was about time I discovered if the Pulsar could even carry the all important bottle of water.

After a successful maiden flight I took the Pulsar home and began hacking away at it with a rotary tool.  The idea was to cut the holes I had planned in the fuselage so the bottle could be attached and the camera could see.  This is pretty much what I achieved, albeit with a few more slips and scratches then I had hoped for. (more…)

The Pulsar’s Maiden Flight

So it’s been 18 days short of a year since the Pulsar arrived in a giant box.  Since then there has been a lot of time spent measuring and modelling and generally designing to figure out how to fill it with stuff to ready it for the outback challenge.

It took a few attempts at various components to get the fit right.  Measuring its sleek, sexy curves proved to be quite difficult.  The last few days have been spent shifting things around to perfect the balance and program my recently replaced radio equipment. (more…)

Meet the Pulsar 4E

As I’ve mentioned a bunch of times on this blog and to anyone I came into contact with over the last 12 months: I’m building a rather large glider to compete in the Outback Challenge.  I recently finished collecting and assembling parts and am keen to see it get off the ground when all the stars align.  You’ll notice that it’s big… really big. And no;  I’m not short 😛

The Pulsar range of gliders should be familiar to most RC enthusiasts.  They are typically a slow, light weight and very well built aircraft featuring enough carbon fiber to make most cyclist jealous.  It is not a scale model, so it doesn’t look like a traditional manned glider.  Instead it has been designed from scratch to be a very efficient radio controlled aircraft.

The Pulsar 4E is the largest of the Pulsar series with a wingspan of 4 meters.  The one I have assembled weighs 2280 grams without a payload, which is expected to be a little over 500 grams of water and bottle.  I have fitted a modest 550 Watt Neu motor to the front which I expect will be just enough power to maintain cruise speed while climbing vertically.

So far, we’ve taken the Pulsar to the airfield twice in attempts to fly it.  Unfortunately we’ve been foiled by gusty winds and some really buggy firmware for my transmitter.  At least it hasn’t been destroyed yet.

I’ll save my rant about Spektrum’s latest DX8 firmware (2.04) being a terrible example of embedded software and something I consider quite dangerous, as it is sometimes in control of very large and fast aircraft.  I’ve downgraded to version 2.01 which I will use cautiously for the time being.

I still have to add the avionics I’ve been working on.  I had some plastic mounts printed that served as both the dropping mechanism for the payload as well as holding the electronics in place.  Unfortunately some of the dimensions were a bit off and it failed at both of those things.  I have some more coming in a couple of weeks and will hopefully have written enough code to make that worthwhile by then.

So while I wasn’t flying anything today, I took the time to make this view of airfield (3MB).  Enjoy!

My Outback Challenge Aircraft

So the massive lack of updates recently has been due to me gaining knowledge in the business management and marketing fields.  I’ve been doing some more coursework to complement my PhD and make me generally more entrepreneurial.  A fairly painful experience so far, and one which will last for another six months.

Between paragraphs of my business plan I did manage to update the designs for Asity as well as complete the CAD models for the parts I need for the Pulsar.  This combination is geared towards completing the Outback Challenge while still being useful to my research.  So here’s an attempt to illustrate what I’m building.

This is the layout of the components I intend to include in the Pulsar4E airframe I’ve got lying around.  It include the typical motor-ESC-battery you’d find in a modern electric RC plane as well as the avionics and camera components I’ve been working on.  You’ll also notice the whopping great water bottle hanging from the bottom.  This is of course the all important payload that needs to be delivered to Joe.

The motor, Electronic Speed Controller (ESC) and propeller blades are being carefully selected to allow the whole aircraft to climb vertically with a payload when the throttle is flat out.  Once it reaches a comfy altitude, the motor is switched off and the propellor folds back.  I’m using a Neu 1110/1Y with 6.7:1 gearbox with a 75A ICE Lite ESC from Castle Creations.  I’ve picked a few props with varying pitches to experiment with.  I’m expecting the aircraft’s takeoff weight to be around 3 kg, and so aiming for a static thrust slightly higher than that.

The moulded parts shown are all coming from Shapeways.  Results so far are promising.  The quality is great and my measurements of the curvy fuselage are actually quite accurate.  Not so accurate are the dimensions I chose for the servo components in the payload dropping mechanism, so I will need a few bit reprinted.

The payload is suspended from a pylon by two polypropylene webbing straps.  I will also add some velcro between the pylon and bottle to prevent it from sliding back and forth.  The pylon fits a hole in the bottom of the fuselage and mates with a beefy servo with a metal horn.

 

The camera is towards the front of the aircraft and also needs a hole cut in the fuselage.  The camera I’ll be using is a fairly cheep 1.3MP CMOS sensor; the kind you would’ve found in a phone from 2005.  It should be just enough to spot a vehicle from 1500ft, and hopefully Joe from 400ft.  I believe the aircraft will be able to stabilise the camera adequately, so I have only included one servo to compensate for the pitch of aircraft.  As I’ll be gliding most of this time, I’ll usually be pitched down and will need to adjust the camera.

I designed a small board to transfer data from the camera back to the main processors in the center of the aircraft.  The board pictured includes a small LVDS transceiver that will translate the parallel interface of the camera into a high speed serial stream, back up the Cat5 cable to a similar chip which will recreate the parallel interface and feed it into an FPGA.  From there it will be appropriately processed and fed into the UHF radio to be sent to the ground.

I’ve also built the first of my latest version of Asity; the avionics I’m developing.  I’ll go in to more detail about this in another post, so for now here is a pretty picture: