So I've decidex to try out something I've been meaning to try out for a while now. Which is to setup my Gopro camera for some aerial photography. Eventhough I've been looking at getting a more polished system like a Dji Phantom drone, I thought there's a lot of mileage I can get just using what I already have. So having studied the best layout for the camera and battery, once the weather clears out, I'll be trying out this system. I'll need to get a Fatshark system to get into proper FPV flying although the aim is not for that at all.  The mass of the Gopro with casing is about 140g with means the all up weight has increased by 26% which means less battery life although one would not need 4min of video anyway. 

It's been a while (over three weeks to be exact) since I've flown the heli. I must say I was quite nervous at first knowing that it's the first few minutes of flying after a long time that are quite critical. I also acquired a headset for my gopro which also worked quite well. But none of that mattered because many headaches have taught me to not have a big head in things that I'm still learning. So only after the third battery did I start with Nose-in maneuvers and a bit of slow circuits. Now that the holidays are upon us (and I still don't have a carry case), I will have to repeat this flight when I come back. I was tempted to take it with so I can get some nice shots of nature and the sea side. But I realised that I can't afford to loose this airframe as when I come back the instrumentation of the IMU will begin. Accumulated flight time: 84 min

Great flying yesterday at the park next to our house. Conditions are again just right to do some circuits and brief nose-in hover. I must say I feel that that I'm really enjoying the heli alot better now that I have tweaked the thrust curve. It remains responsive and quite stable around hover. Started using my homemade cap mounted gopro. The videos look great. Visit here to see some of them. It's nice and stable and after a while, you forget that you have it on you. Accumulated flight: 79min

So once I'm done doing #flighttest #data #reduction and #analysis I'm tackling the development of having these two @atmelcorporation #atmega328 talking to each other over I2C bus network. #coding #code #uav4africa via Instagram http://ift.tt/2gY9dG1

So decided to try and get some flight time at a park near my house. The calm weather had it that I managed to do more nose-in hover and slow circuits. All in all, I will need to make another landing gear as the plastic material is too brittle to hand hard landings.  Accumulated time: 64 min

It was another windy day of flying. That's when you appreciate flying the heli calmer weather. Managed to clock in 8 minutes of flight doing various maneuvers. included side hover. I decided to put my Gopro Hero4 silver to good use by capturing some videos from the ground. It was not the perfect angle although the dynamics of my flying in windy weather was obvious. I was very choppy on the sticks (due to wind mainly) which made me question how the challenge that's awaiting me when I turn this heli into autonomous machine. Had a bit of hard landing which bent/broke the landing gear. But the heli does not know any difference. Accumulated time: 52 min

So today was a really good day because I've managed to hit just under 15min of flight using the three batteries show in the picture and most importantly with a failure. The wind was alot calmer today which made flying a breeze (excuse the pun). I was also able to do nose in and slow circuits which was a huge confidence builder. Now on to the specifics: Even though I was doing tail control (and to be fair there's a pretty bandwidth gyro in the loop as well), I found that rotating the heli to get it into a nose in position caused quite a drift away from me so much so that I had to quickly bring to tail-in in order to recover the heli (achieved about two succesful crash-worthy recoveries - Yeah!). This could potentially be a inherent in the dynamics (which i think it is) or there's further tuning that's required. In any case, success once again. I can see why accumulating more flight time in bulk helps. You get to correct and improve that crucial confidence onto th...

#samtheman analyzing his #helicopter #toy with such attention. #drones watch out for this guy. #takingover #uav4africa #proudpapa via Instagram http://ift.tt/2g35NTr

So today was a day when I decided to increase my flight time per session. I've started using two battery packs which meant that I know have to change over and also do some tweaking/learning on the transmitter to have a more comfortable flight. Even though It was quite windy (which is pretty normal now), I find myself being quite nervous still, Although It will go away with time. It could also be that I know how powerful this heli is and that I'm really wary about doing too much too quickly. To my credit, the heli got away from to about 50m and 15m in height and almost freaked out. Luckily I didn't panic and slowly brought the heli back in eventhough I was really struggling to make out its orientation. I was tempted to run closer but I must say I froze a little bit. I realize the amount of wind pushed it away and I wasn't actively controlling the throttle on the heli. Now I know better. I decided to have a couple of landings (some of them really hard) s...

We're in lesson 5/100 before inverted flights. Decided to up ante and do min 10 min of flying for every session. Three packs of battery should give me 12min of flight. #uav4africa #drone #rcheli via Instagram http://ift.tt/2eEwDDJ

Another succesful 4:30 min of tail-in and side to side hover flight. Accumulated time: 21min. I found it quite difficult with wind to stay at a consistent height, I landed the heli twice and I should have made changes to the throttle/pitch curve or the mixing. It was quite challenging flight in hover in gusty conditions but I'm finding keeping the heli in the air longer much easier. Next is to slowly transition into face in and then nose in (although I feel I'm more comfortable nose-in). In the meantime, I've started working a instrumentation platform that will be integrated between the landing gear and the frame of the heli to hard gathering data. That should bring about more result-orientated fun!

So after the crash from the previous flight, I received a new set of landing gear. Given that I was on daddy duty this weekend, I didn't get to do any flying. So today during lunch I decided to get over my fears and get going with my flying. One thing that got me quite nervy (as if I wasn't apprehensive enough), was that the wind was quite gusty today. Windsurfer  reported about 7 m/s (25 km/h) winds gusts with roughly 6 m/s (21 km/h) wind speeds. But in my mind (call me foolish) I thought this would be a good test of my hovering skills in the midst of all disturbances. After binding the heli, I took to the skies with the thumping heartbeat. The wind gusts in the open field started becoming more evident in the control of the heli. A couple of gusts even elevated the heli a few meters higher eventhough i had reduced throttle. Then a sharp gust almost caused the heli to barrel roll into the ground. But i kept my cool and decided to persevere through. I was tempted to allo...

The generation of embedded aero tables from an automated process which uses Digital Datcom has now been checked. The phased approach was used. The longitudinal dynamics were checked first through effectively flying the glider ballistic in the pitch only. Once expected results were achieved, an initial sideslip (over 10 deg) was introduced at the start of the simulation causing the excitation of the lateral and directional aerodynamics. The checking of these was more tricky as one needs to have a good understanding of the geometrical effects of fixed-wing airplane on its aerodynamics. Below show some plots of the angle of attack and sideslip in a disturbed ballistic trajectory whereby all channels of the aircraft are excited. Given that now we have 6DOF simulation model with a complete aerodynamic model, flight control design and introduction of actuator dynamics can now proceed.

So decided to upload my coding scripts and share it with the world. I'm not officially in the #opensource business. One actually gets to realize that the only to harness an idea, is to throw it out in the open. #uav4africa #coding #movingup http://ift.tt/2f1HHqB via Instagram http://ift.tt/2equZ8k

So I finally found an enclosure for my automated sprinkling system. It uses a photocell for day/night switch. I'm planning to add two potentiometers to control duration and repetition without flashing new code. A master switch that restarts the program will also help. Will post some videos on how it works. EDIT: Managed to add the master switch on the microcontroller. Given than the solenoid in Normally-Closed, the master switch prevents the current to drawn by the solenoid. #coding #atmega328 #uav4africa via Instagram http://ift.tt/2f1G7or

So eventually the infamous first crash happened. To be fair I had flown once before this one and I was getting quite confident on understanding the dynamics of Heli. But the mistake that I made was that there was quite a bit of wind and I decided to do some circuits at quite high altitudes. The curse of over confidence and the urge of trying to do too much too quickly caught up with me. Anyway, the crash was more me loosing orientation and causing the Heli to land hard snapping the one of the landing gear. From first inspection, it doesn't look like much else has been damaged especially the carbon fibre main blades with costs a pretty penny. But from what I could see, this Heli is incredibly responsive to radio inputs which makes me wonder that I might just numb down the rates curves a little more abit. Or perhaps just est some humble pie and keep clocking minutes the slow and almost boring way... Oh well, now it's a week waiting for new parts.

Today during lunch time, took the heli out for another spin and consistently in my mind, I was wondering about the numerous time I stopped being careful after the first round of success and lost very expensive aircraft. So having such in mind, I took it slow and easy in a tail-in hover will a slight side hover. Halfway through the flight I decided (or the devil in me) decided to put the heli in a nose-in hover and my pulpitations started all over again. But was surprising was how stable the heli was even in the presence of mild winds. Managed to perform half a circuit and landed the heli once the 4min was up. Good job!

So it was my first flight with the Blade 300 CFX yesterday and like anything new, the rush not to end in an epic failure that will leave you gutted for days was upon me. After doing a transmission/range sweep I put the aircraft through its paces. Coming from the Blade mCPX heli, going through the structural modes of the heli caught me by surprise thinking there's something wrong with the heli, Anyway pushing through it, even with a slight breeze, managed to get the aircraft in the air and maintaining tail-in hover. Most of time was spent in getting a feel of the controls and the dynamics on the heli. It looks very responsive which made you think twice about having any sudden knee-jerk reactions on the radio controls. After 4min, I landed the heli with raw smiles all around my face. Good job!

So I've bumped into the idea last night of using the I2C bus protocol to connect multiple #atmega328 chips to emulate the airframe/environment kinematics and the GPS NMEA messaging in order to complete HILS system. This then means I would be able to be able to perform synchronous serial communication at specified rates as per the real hardware in testing the autopilot controllers and waypoint navigation. #uav4africa via Instagram http://ift.tt/2ek78T9

Completed the debugging of the 6dof simulation in the longitudinal plane. Used #mvs and #matlab Mex functionality through process attachment. Now activating the lateral and directional dynamics to in the loop. Using a ballistic flight as a test case. #uav4africa #drone #coding via Instagram http://ift.tt/2esU01g

So as most of you know, I've finally decided to develop a generic script that will be used to generate aerodynamic data using Digital DATCOM. It's been a long-winded process but I'm almost ready to do some testing on it.

So it turns out that I was very optimistic about just using a gain mixing of accelerometer rand gyros than computing a DCM matrix of the aircraft rotation. So I decided to overhaul the code by creating data structures that will hold the information requires for such computation. I must say that at the back of my mind I was really worried about the computational time that these calculations will take in the small Atmega328 micro. To my surprise, provided that one sticks with a minimum of division operands, float arithmetic is actually quite fast even in an 8-bit controller. Given that this application is for high L/D aircraft and who’s mission is mainly waypoint tracking, the slow changing dynamics can be reasonably captured with this environment. The bad part of the implementation was to discover how quickly the gyro drift (especially in the roll channel) hurts the computation of the Euler angles. (See the pics below), even-though all sensor are bias compensated fro...

So I've decided with the change of the DCM matrix and PI controller for navigation to change fundamentally the code layout with the use of data structures to make more sense of the information been passed on. I also spend most of list night trying to get my head around whether float division is really such a problem. We'll based on references xxx and xxx it is. Float memory allocation is not a real issue but float division can really boggle down your code to the core of tortoise pace. So this reference xxx explains that one can find an alternative around this issue which should speed things up quite a bit.The fact of the matter is that float division should really be an exception in any type of code (irrespective of the compiler and host). A lesson well learnt.