My first UAV - Aerial Photography with Android system - Discussions

Hi There,

I am looking to build an UAV for an aerial photography project, so here I am new to this incredible knowledge base you guys have created ! However I do have few question.
I ve based my choice on the Predator ( Because I just love the nitro UAV RQ1 Predator 63” )
Then I’ve seen the Chris project with the Digital Camera which definetely confirmed my choice.
I am not knowledgable about frames and R/C but I totally am when it comes to computer OSes and geeking, so I’ am trying to have a full open source UAV - From the Autopilot to the android platform.

The goal of the UAV would be for me to set up GPS coordonates and ideally the Autopilot ( Ardupilot + Imu shield would be my choice obvisouly ) would fly the UAV and the pictures take shots on the specific location ( For this solution , I am still thinking about two solution: A digital camera triggered by the GPS or an Android Device with a VNC connection )

The point in using an Android device is that:
- I can log all flying datas
- I can take geo-tagged pictures and have them uploaded to in real-time to my ground station
- The device can be GPS localized if needed ( In case I might have to recover the UAV )
- SMS remote control

The problem is that it will not allow me ( yet ) to trigger the camera reaching a GPS location, There is no such apps that I am aware of. This will oblige me to stick to the ground station from where I will have remote control over 3G network on the Android Device. Still sounds OK to me.

I just found an app that Automate task on your droid device, I will see if that allows you to trigger
the camera based on the location & will let you know !

Having an UAV based on android device allows still hundered funny function as soon as it can be remote controlled over 3G ( Wireless speakers - Leave LED text message in space by night http://www.siftwire.com/light-writer-pov-effect-iphone.html and other hundereds stuff that doesn’t interest me )

Regarding the hardware, I ve decided to based my UAV on the Papajeff’s config:
- UAV RQ1 Predator 63” / Engine: 400XT Outrunner RC Brushless / Batteries: ?
- 25A ESC / Prop: 9 X 6 SF / AR6100 Rx / DX-7 Tx / Servos 4x nitro 9G RC Micro / Bigger Wheels

My Question is about the batteries I need at very minimum 30min flight / 50min would be perfect : Which batteries shall I use ?
I’ve seen that page below: A wide selection of Li-polymer battery packs: Capacity from 40mAh to 5350mAh; Voltage from 3.7v to 44.4v; Continuous Discharger Rate: 10C\15C\ 20C\ 25C \30C\ 35C (http://www.alibaba.com/product-gs/324245684/5000mAh_11_1V_40C_Lipo_Battery.html)
I noticed that the voltage should be 11.1v as the rest of the system preferably. What about the Discharger rate, this is a point that I ve missed ?
Which configuration would give me the best autonomy , and is it possible to run more than 1 battery pack ( Like 3 batteries pack if needed ) ?

I Have never assembled an RC Plane before, never flew one, so here the Autopilot comes in, I’ve seen that the Autopilot can autoland and take off, does this process requires me to do anything more than programming the Autopilot ?
Regarding the Autopilot, the zone I have to cover does have some Aerian electric cables crossing from zone to zone and some change in the level from +/- 50 meters. Does the Autopilot can control the altitude in some accurate point or is it possible to define it following the map utilized such as googlemaps ?
I have seen some RC Simulator and will definetely get one at some point meanwhile, is it needed to have the AR6100 Rx & DX-7 Tx if I do not intend to use RC controls ? ( I know as a backup solution you might consider this mandatory, but without skills or without Autopilot it seems to be the same at the end in case of problem ! )

Another point, I would like a parachut to be activated in case of hardware failure, is this function hard to implement ?

Regarding the Android apps so far:

- Automate it ( I have To test if that app enable you to trigger the camera on GPS position )

- Droid VNC Server : Remote control your android device from PC ( Ground station )
- Mytracks : Logs GPS track on googlemaps PC ( Ground Station )
- Dropbox : Upload any file from an android device to any PC ( Ground station )

- Where’s mydroid : Locate your android device on a GPS map , Remotely wipe or lock the android device

- GPS status and toolbox Free / GPS Speedometer / GPS Essential ( With HUD ) : To log flying datas

Droid VNC server allows you to see the Device screen in a graphic user interface ( This allows you to perform any function as if you had the device in hands as long as you are covered by the 3G network )

Thanks for the help !
J -

Well you seem to have the programming aspect down, but you may be disappointed by the next bit of news, you should learn how to fly R/C before you attempt to build an autonomous aircraft. The reasons are two-fold, one, the flight dynamics are completely different than conventional aircraft since most sUAS are overpowered compared to full size aircraft. And two, it will be much easier to trouble shoot the autopilot if you understand how it was supposed to work.

Also the RQ1 Predator 63” is usually a poor choice for beginners, most recommend a skyhawk or easystar to begin - easy to repair after crashes...which there most likely be many.

Also the original ArduPilot does not have many features built in, thus if you want parachute control, camera triggering, etc - you might want to look at the ArduPilot Mega - unless you plan on doing most of that through Android.

As to R/C, I would suggest that you don't rely on just the autopilot, the ArduPilot project is a remarkable thing, but it is still maturing, with the nature of constantly evolving opensource it would be wise to always have a manual back-up. Further, autonomous take-off is relatively simple to tune once you have some actual aircraft flight characteristics, ie acceptable climb angles, climb throttle, etc. Autonomous landing, well that's much more difficult but not impossible; the point being, neither at this point are PNP features available right when you have your autopilot, you will have to tune them specifically to your aircraft, which requires you to learn how to fly R/C.

And yes, the ArduPilot family will follow a pre-programmed route using 3-D waypoints.

As for battery choice, that depends on your consumption, you will need to figure out the consumption of your motor, autopilot, and any other electronics, ie Android device, then that'll let you know what size and set-up of batteries you require. To answer your question generally, yes you can arrange battery packs either in series or parallel depending on what you want out of them - more voltage/longer duration respectively.

There are many articles on the web about proper: charging, discharging, storing, use, and disposal of LiPo batteries, please be careful, they are extremely dangerous!

I don't want to discourage your ambitions, but understand that this is a very involved & intensive, though extremely rewarding endeavor you're planning. The best, ie less frustrating, plan is usually to start small and grow incrementally.

Good Luck!

Replies

Kyle February 22, 2011 at 11:50am

Well you seem to have the programming aspect down, but you may be disappointed by the next bit of news, you should learn how to fly R/C before you attempt to build an autonomous aircraft. The reasons are two-fold, one, the flight dynamics are completely different than conventional aircraft since most sUAS are overpowered compared to full size aircraft. And two, it will be much easier to trouble shoot the autopilot if you understand how it was supposed to work.

Also the RQ1 Predator 63” is usually a poor choice for beginners, most recommend a skyhawk or easystar to begin - easy to repair after crashes...which there most likely be many.

Also the original ArduPilot does not have many features built in, thus if you want parachute control, camera triggering, etc - you might want to look at the ArduPilot Mega - unless you plan on doing most of that through Android.

As to R/C, I would suggest that you don't rely on just the autopilot, the ArduPilot project is a remarkable thing, but it is still maturing, with the nature of constantly evolving opensource it would be wise to always have a manual back-up. Further, autonomous take-off is relatively simple to tune once you have some actual aircraft flight characteristics, ie acceptable climb angles, climb throttle, etc. Autonomous landing, well that's much more difficult but not impossible; the point being, neither at this point are PNP features available right when you have your autopilot, you will have to tune them specifically to your aircraft, which requires you to learn how to fly R/C.

And yes, the ArduPilot family will follow a pre-programmed route using 3-D waypoints.

As for battery choice, that depends on your consumption, you will need to figure out the consumption of your motor, autopilot, and any other electronics, ie Android device, then that'll let you know what size and set-up of batteries you require. To answer your question generally, yes you can arrange battery packs either in series or parallel depending on what you want out of them - more voltage/longer duration respectively.

There are many articles on the web about proper: charging, discharging, storing, use, and disposal of LiPo batteries, please be careful, they are extremely dangerous!

I don't want to discourage your ambitions, but understand that this is a very involved & intensive, though extremely rewarding endeavor you're planning. The best, ie less frustrating, plan is usually to start small and grow incrementally.

Good Luck!

This reply was deleted.