Been a long time since I posted something Now I'm back, since my exams are over

I've been thinking of designing a quad that could fly atleast an hour with a GoPro and brushless gimbal, and this project aims to do exactly that. I'm building this copter for filming purposes and long flight is critical to my application. When the RCI anniversary sweepstakes announcement came in , I thought this would be the perfect time for starting the build...

Features to be integrated:

• Onboard linux PC (PCDuino) - primary flight controller running all high level algorithms [realtime kernel] (own code) - EKF , navigation and main PID loops
• APM 2.5 as slave for RC input + output +  Sensor acquisition (Hacked AP_HAL libs)
• 80 min+ flight time without gimbal (40 min + with gimbal)
• LiIon battery pack (custom designed Panasonic NCR18650Bs in 4S4P configuration) 
• Digital 802.11 downlink (Telemetry + Video channeled via UDP) - (Ubiquiti BULLET M5)
• DIY Brushless gimbal (I'll be hacking the BruGi code to calculate the PID with inputs from the FC to improve the attitude estimate)

[Note : I'll be running basic telemetry 3dr radios + 5.8ghz analog FPV until I get the Bullet M5s and the copter has broken in with a couple of flights]

A set of parts arrived yesterday and I got working on the build. Still waiting for motors + ESCs + LiIons + Gimbal motors + props , etc.
I already had a customized Dead Cat frame with aluminium arms, from which I will reuse the center plates.  I ordered some long arms + motor mounts from Goodluckbuy which arrived pretty fast. I will use them on this build.

Arrival of parts :





First fit of arms + FC:





RC Rx + GPS installed:





More pics coming soon

Kabir

Interesting. Subscribed. 

First look at the Lynxpilot AP - Bench testing going on of the sensor fusion and debugging serial overflow errors Using an old APM 1.4 as the slave for now. The white board is a pcDuino v2 running my self-compiled RT PREEMPT kernel to enable high resolution timings as required by the fast algorithms. The board has a 32 bit ARM Allwinner A10 SoC running at 1.2 ghz. Presently, it is accessed via ssh wirelessly and also has a samba fileshare for pushing code to its storage.

Quote from: sundaram on March 22, 2014, 10:46:40 AM
Interesting. Subscribed. 

Ditto 

Good project. Following.

interesting project

Kabir good to see you back, and indeed a nice project.
I wonder and am curious what brought you back is spite of this

Quote from: mhkabir98 on February 20, 2013, 05:20:53 PM
Let my 50th post ever be my last post here.
Kabir

Is it Sweepstakes ? or you came around? either which way we are happy to have you back   (I also see you have been quite busy at openpilots xdavelopers etc, Dher se aaye Dhurusth aaye, aaye tho sahi )

Welcome back

PS
Why don't you remove those infamous loiter video from youtube and those related pictures from photobucket. For your own good, wont help you in your future endeavours, Just a friendly advice  

Thank you Gusty sir I saw my follies... You were right. Thank you for your advice. I see that you still remember the incident XD

I had removed the videos / photos already I thought... ? I'll check anyway

Thank you once again. Glad that you're following this project , I won't disappoint you .

Kabir

MOD EDIT

Unnecessary quote removed

i am sure you wont, and keep posting your work here as well and keep'em boys enthralled

Today I found the power distribution board which girishsarwal sir had sent me (and had subsequently lost) and decided to use it on this project.

I am creating a stack on top of the PDB with a G10 plate to install the linux board . The ESCs (AfroESC 20As running i2c feedback back to the FC) will be locked under this plate.





ESCs go under here :



Kabir

Primary installation of Linux board is done , relocated Rx and fitted the arms again to check for obstructions. It folds beautifully



Isolated brushless gimbal mount is ready, waiting for motors.





Kabir

What a coincidence , even I was planning for a similar one for long flight time..
Not exact in design.. by the way beautiful build.. my items will be arriving tomorrow lets see both of our results soon..
All the best:)

Just awesome !!! subscribed!!!

Excellent, sub'd!
You dont built so often, but when you do, you nail it!

Wow, really nice project. I am really interested to know more details on how the linux pc and the apm work in tandem.
Even i am trying something similar with respect to the control of the quad using a beefier processor and using an ardupilot as a slave. I am primarily trying to use a monocular camera for autonomous indoor navigation. I am planning to use a Nexus 5 as the beefier controller and send signals to the apm. But i dont know how the two would communicate yet. I had plans to have a beaglebone black in the middle but was unsure if it will work.
I will be closely following your build. I hope i can contact you if i need any help as i am a newbie when it comes to quads, or for that matter any flying robot.

Thank you for all the good wishes guys

@ayu135 Of course I'll help if you need it. I've worked with indoor SLAM using a neato xv11 and a Kinect using ROS, and processing power is the main problem. I wouldn't recommend that you use the Nexus 5 as I/O is limited. You're better off going with a HardKernel ODROID-X2. As for monocular indoor navigation, its nearly an impossibility with present-day low-power processors onboard. I've been there and done that Better off shoving the data off to a offboard ROS node to do the heavy lifting.

Kabir from where are you sourcing these batteries?
Can you shed some light on estimated current draw for your setup and discharge rate/capacity of your planned 4s4p pack?

I assume you would be going for high-efficiency low kv motors with big props for long flight times. Went through a thread on Rcgroups where ppl have achieved maximum flight times, and in all those cases primary goal was longer flight time using the same batteries while keeping the auw minimum. And right now your setup seems to be on the heavier side.

http://www.rcgroups.com/forums/showthread.php?t=1880665

Hey Sidewinder,

I'm sourcing the batteries from China(dealextreme).The 4s4p pack has a 3-4C discharge and 13.6Ah capacity at 770g. I might also use batteries from the chinese company GBE, which are LiPos, but with 3C discharge and lightweight too.

EDIT : My AUW will be around 1800g without gimbal. I'll be using multistar 380kV motors which have peak efficiency at around 30% throttle. They'll be drawing around 3A each at hover.

I know that I'm on the heavier side with this build, but my main aim is to demonstrate the high performance Linux FC and achieve decent flight times. There e is another thread somewhere on RCG where people use off shelf parts with heavy DJI equipment and still get pretty good flight times.

I've also tried to optimise weight wherever possible, and the weight will also get reduced once I install the bullet M5 and unify all the wireless links.

Kabir

I got Lynxpilot's Linux <-> AVR data link updating reliably at 100hz (finally ; after hrs of debugging overflows ) and coded a rudimentary sort of command line interface working over the ssh link. Also finished onboard integration of the linux board. The EKF is working pretty well after doing bench tests and I get a rock-solid attitude estimate with GPS fusion, thanks to Matthew(picopter guy) The code is almost flight ready , but still need to implement some safety features,  a kill command , fix some problems with the PID not updating as fast as IMU data coming in and lastly some crosstrack calculation problems in the navigation module. 





Kabir

Quote from: mhkabir98 on March 23, 2014, 04:36:33 PM
I'm sourcing the batteries from China(dealextreme).

Are you sure they are genuine ? Lots of fakes on ebay and Chinese websites with lower capacities than what is mentioned. EndofDays used genuine panasonics sourced at 16$ a pair.

True,that. I've read that people had brought from DX and were happy with the packs, but it needs more research. Can you suggest any other sources? I searched, but to no avail... Everywhere seems to be out of stock.

After some crucial design decisions I took yesterday, I'm tending more towards GEB lipos. I'll write to them for a custom pack, let's see. Will keep you all updated.

Kabir

The guy has put up a video on testing the batteries on DIYDrones and claims them to be genuine. Talk to him and see if it fits your purpose.  http://store.mygeekshow.com/product-p/ncr18650b-pack-kit.htm

Incidentally a guy tested the GEB batteries you mentioned ,but they are highly priced, you can read more @
http://diydrones.com/profiles/blogs/getting-to-100km-with-a-big-help-from-geb-8043125

http://www.rangevideo.com/en/3s/314-rv-endurance-18300mah-111v-12c-3s3p-lipo-battery-pack.html

Yes,  I've gone through those before. Trent(mygeekshow) is getting his cells locally, which unfortunately doesn't work out for me... They're selling 1 for $13 + shipping which is just too much....

I've decided to go with a 4S5P pack of NCR18650Bs ( = 20 cells), which i calculated would be optimum for my setup at a 2kg AUW for 60 mins of flight.

EDIT:

I've found these 4 sources for (seemingly genuine) unprotected cells:

Out of Stock:
http://www.orbtronic.com/batteries-chargers/panasonic-3400mah-18650-li-ion-battery-cell-ncr18650b -- VERIFIED ORIGINAL (Shipping too high though)
http://www.fasttech.com/products/1420/10001980/1141100 -- VERIFIED ORIGINAL

In Stock:
http://www.banggood.com/2PCS-NCR18650B-3400mAh-3_7V-Rechargeable-Li-ion-Battery-p-909137.html
http://dx.com/p/panasonic-ncr18650b-3-7v-3400mah-rechargeable-li-ion-battery-black-green-2-pieces-180030

**Anyone knows anyplace in Kolkata where I can get hold of a battery tab welder for getting the pack together? I could use a high-powered soldering iron, but I'm not too keen on that idea.

Kabir

Got the UDP connection to GCS working via the pcDuino's onboard wifi  ATM, it just sends a very very basic subset of the mavlink messages via the link. Connects to DroidPlanner2 on my tablet, but almost nothing works (no mode setting, nothing) as they aren't implemented yet.



Kabir

Kabir, I have my eyes on your project, I am going to build a quad soon to steal that quad of yours, mid-air ...quad jacking!