Saturday, 18 December 2010

Xplane 9 preliminary sim model


I said I would upload this at some point to the blog, so here it is-



http://www.megaupload.com/?d=F3GXWYP5

This is just the aircraft model, you'll need the program (Xplane 9) which you can get a demo download here. Its no different from the full version, except that you can only fly 10 minutes.

http://www.x-plane.com/pg_downloads.html

Dont worry about the high specs too much - my laptop is only a 1.6 and can run it, as long as you press the "get me lost" button until it makes an airstrip in the sea, anyway. (Hence no scenery in the picture I've uploaded!)

you can fly by the mouse or an analouge controller, I use an analouge. There is an option to view from the airstrip for model aircraft flying, just before you do you'll notice the inside view has a small dial with a wheel on the left of it - thats to adjust the elevator trim. You'll understand why you need it pretty quickly once you get flying.

Just thought this'll be something fun to try and since its a laminar flow sim it'd give a reasonable Idea of how such a design might fly.

Let me know what you think or if you have any problems anyway. Have a good christmas all!

Wednesday, 8 December 2010

Frame Material

Frame work : Balsa wood ribbing with stringers (similar design as picture).

Density - 170kgm3 Board thickness - 3mm






Lining: Solartex (giving the finish of the picture below)
Wing attachment: rubber band (this may sound unconventional but i have seen it on alot of models and its a simple and stable way to attach the wings)



....more will be added later!

Monday, 6 December 2010

URSUS - good example of the design we're looking at.



Full article with links to more pictures here -
http://diydrones.com/profiles/blogs/ursus-epp-platform

Nice example of the sort of design we're aiming for here. it's a bit smaller and more lightweight than our design, but an example none the less.

We're looking for taller gear (as this just drags on the ground, could be a problem launching from and landing on unstable ground) partly for clearance, partly to absorb hard landings. With a 1 kilo payload I don't think something as light as the URSUS would do it, but its a nice example of the design we're aiming for. The prop is going to be lower and larger also than the above.

Hope this inspires anyway guys.

Thursday, 2 December 2010

Propulsion parts

480 O/R 890 (C28-20) ENERG B/MOTOR 4445560

Dimensions: Length 40mm, Diameter 28mm

Thrust with 11x4.7 SF propeller: 1115g

Current: 18.2A

Power: 188W

RPM: 6900

Volts: 11.1V

Weight: 84g


E-Pro SP30A BEC Air ESC

Peak Current: 35A

Dimensions: 42x24x7mm

Weight: 28g

Saturday, 27 November 2010

Introduction, and sensor systems

Okay, decided I'll get the ball rolling here.

What I want posted is mainly common material. So anything thats going to affect everyone elses work. There is no need to go into any hugely specific depth about how your individual parts work, but anything revelant to anyone working around the design of it.

Though, I would like if possible someone to update me on the current design from the meeting I had to leave early from, as I've been informed there are some significant changes to the design.

so anyway, here is some information regarding the systems I want to install into the UAV. Its information regarding unit dimensions, mounting, and where they are located, as well as links to the actual devices themselves, for anyone curious.
--------------------

These are the sensing systems employed at this time, along with some conditions of their placement and operation. All sensors require cabling and a header to connect the cables. This could add up to 20mm above or alongside the devices, depending on how the connector is chosen. The only exception to this would be the GPS, which already has a socket fitted (but will still need a connector for that socket)

6 DOF RAZOR IMU

MUST be placed as centrally as possible at an exact right angle orientation.

IDEALLY would be best mounted soft and free from vibration, which would interfere with the accelerometers.

NOTE : use this data for reference only. This device has been superseded and will likely change to two individual modules now, depending on availability. Though they will likely together be about the same size, and will need the same locating regime.

Dimensions: flat circuit board, 20x40mm

http://www.coolcomponents.co.uk/catalog/product_info.php?cPath=36_58&products_id=446

GS405 GPS

MUST have direct line of sight to the sky at all times, ideally on top of the aircraft with aerial pointing skyward.









Weight 16g

http://www.coolcomponents.co.uk/catalog/product_info.php?cPath=21&products_id=222

3 AXIS MAGNOMETER

MUST be placed at an exact right angle orientation, as far from any magnetic interference source as possible.

Dime

nsions: flat circuit board, 12.7x12.7mm

http://www.coolcomponents.co.uk/catalog/product_info.php?cPath=36_59&products_id=407


XBEE UNIT

MUST be placed near exterior of aircraft, so the aerial which is affixed to the Xbee unit can exit the aircraft. Given it is intended to communicate with a groundstation of sorts, such as a laptop, this could be mounted under the aircraft, but this isn’t absolutely necessary.

Dimensions: double stacked circuit board, 30x35mm, height estimate 15mm.

http://www.coolcomponents.co.uk/catalog/product_info.php?cPath=55&products_id=295

(Only parts that will be onboard are the Xbee regulated, and one Xbee module. Other parts are ground station components)

IR RANGEFINDER

MUST be placed under aircraft, and view the ground through a window to protect the sensor from weather conditions. Ideally, nearer to the centre of mass as possible. (Though payload will take the very centre area) so most likely just behind the payload.



















http://www.coolcomponents.co.uk/catalog/product_info.php?cPath=36_57&products_id=236

PROCESSING UNIT

The weight of the processing unit can be assumed to be somewhat low, at a guess I wouldn’t expect more than 250g. This is mainly due to the regulators and cabling that will be needed, not the processors itself. This would be placed as specified before in an area set aside and dedicated to the processing system.

This is undecided because the difficulties likely to be encountered so far as not entirely known, nor are the solutions for overcoming those difficulties. Therefore, the processing solution is currently a very open design.

The area the processing unit is expected to take is up to a maximum of an equal size to the payload area, but of less weight. (about 4x5x3 inches if I remember correctly? Steve should have a more exact figure for this)

I've also included an image of a side and top view to give a rough idea of how I would expect the layout to be taking those criteria into account, in a pull prop design, since I've heard we may be heading to a prop direction.















Any more questions, feel free to leave a comment. And I look forward to seeing everyones work!