Over the past two years, the research and development team has been developing a method to identify faulty motors on a drone without interrupting a mission (automated or manual). This is of high interest as it will give the pilot more information to ensure the successful recovery of the system in the event of a fault. The team of engineers has developed a Machine learning (using Artificial Neural Networks) framework that superimposes the dynamics on the controls in order to detect and locate a fault in a rotor without compromising the mission. The graph above shows simulate a rotor fault once the drone reaches 9 m/s and the fault identification system (FIS) detects a fault 1-second later. Once the other rotors are analyzed, the Rotor1 is identified as having a fault and this information is sent back to the pilot. It's important to know that even though a major fault has occurred, the drone a capable of flying for some time until instability grows and the drone becomes unc...

The impact (good and bad) of drones in society is no longer in question. But what will it take for drones to impact a traditionally outdated, low-profit-margin civil works industry through the use of technology? The solution lies in a low-cost approach. One could say it all started when a bunch of scientists realized they could do a far better job in measuring objects accurately and at a distance rather then an individual putting himself in harm's way and using expensive/primitive equipment for the same task. We're talking about photogrammetry. In a nutshell (or should I say according to Wikipedia), Photogrammetry is the science of making measurements from photographs, especially for recovering the exact positions of surface points. In more simplistic terms, provided you have some form of frame of reference (like a ruler) you can determine the physical properties of objects and their exact location to the accuracy of the remote sensing equipment used (a 4K-size imag...

The objective for this milestone was to integrate the same model functionality developed and analyzed within the Matlab/Simulink environment into a mature environment that will be able to test most functionalities of the Flight controller software that will be flashed for real-flight testing. The decision was to either migrate the Ardupilot (in this case ArduCopter ) software into the Matlab environment or integrate the highly nonlinear quadcopter model with flapping dynamics into the Ardupilot environment. The former option would mean no easy integration with Mission Planner and the real-time sofware-in-the-loop ( SITL ) testing tool (which also includes the infrastructure to communicate with the Flightgear 3D visualization environemt, while the later with make use of singular environment although the software development effort would quite tedious and error-prone. It was chosen to go with the first option as this was thought to be lead to more mature verification method prior...

So the notion of upgrading my already awesome (if I can say so myself) looking drone to aerial videography using a 3-axis gimbal has been bugging me for a while now. I mean, why not? At least that will get me to fly the drone alot more and use it for other purposes. The fact that I only need a gimbal and a landing gear (given that I already have the awesome Gopro hero 4 silver), should be providential enough to just spend the dollars required to make this happen. But then one get's to think, why I am doing it for? I mean does my research of intelligent flight control ACTUALLY need aerial capability? One could argue that testing your software with a drone representative of an actual commercial drone could only enhance the validation/justification of the research.  But the ultimate question is, how MUCH distraction will this capability introduce to the essence of what the doctoral research is trying to achieve? Will I gain more information given that I've got now no...

So i've been looking over the last few months how I can get to fly more of my quadcopter drone for both research and leisure. The major drawback of the 1.6kg drone is its form factor at the time. Being a H-frame quad with cross rotor length of over 80cm, I had to purchase 110L storage bin to keep it safe and damage-free. After much research I ended up a natural solution that would involved just a steel saw and good eye for detail. The other (obvious) requirement for this folding mechanism is that it should make the deployment time as fast as possible with a few if not no special equipment. This led the the solution of cutout the area around the second bolt of each arm to allow pivoting action on the first bolt. The cutout should also be such that bolt hole remains to be used as a stopper to maintain symmetry along the quad x and y axis. The high contact friction will be used to ensure the arms remain in the required position throughout a particular flight. After much sawing and...

My research drone, given the lack of research funds, was a fourth-hand quadcopter drone which I resuscitated and started getting good flight test results. I even wrote a paper on it with the hope of publishing. However, the previous guys didn't have an appreciation for neatness so the drone looked like a wire fest. See below: So in order to make a clean start (without breaking the bank) was to remodel the airframe into something more commercial (with the hope that it could serve as a aerial photography platform - always wanted a DJI). So what I did was convert the space between the two main plates and layout the power electronics which included the ESCs, the distribution joint and the power module. I cleaned up the residues of double-sided tape that appeared everywhere and made provision for the Pixhawk in a more central position. And this is what it looks like now:   Mission accomplished. Now it's time for testing everything still works and for the first tes...

Over the course of the past 2-3 weeks I decided to take the plunge of learning a new training algorithm which had quite alot of attention in the academic community but was also well constructed for easier implementation. The work by Peng et al on developing the Continuous Forward Algorithm (CFA) was my subject of attention. The overall premise behind implementing this algorithm was to investigate less memory-intensive machine learning algorithm that will not sacrifice accuracy or robustness. The ability to have a real-time learning system for low-cost electronics (such as the Teensy 3.6 ) has huge implications for the commercialization and affordable access of intelligent drones specifically for developing and even under-developed economies. The far-reaching impact of having technology leveraging efforts of farmers, herders, game rangers, biologists is the next wave of industrialization. This is the essence of this blog. The journey is very exciting and eventual results even mo...

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

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 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.

Yeah that's right. Everywhere you go, including some intern projects at my company, quadcopter drones is the current trend. The marketing success is simple. It's a lot cheaper and less complex and than a comparable RC helicopter. They're virtually no mechanical moving parts (expect the platform itself). And it's perfectly suited for camera attachment. So hot combination has spawned the quacopter drone revolution. I've always been against following a trend just for the sake of it. But considering that I need perfect weather test fly my flight controller only makes sense to start modifying my code to accommodate for a quadcopter. The controls are pretty straightforward and the design is incredibly simple. Another design dev coming up!

So I decided to build a new aircraft since my 2m glider only gave me limited flying options. This is was quite a quick project as all was designed in Solid Edge including the electronics. This enabled me to work out the mass and balance throughout the design process. The total weight sits at 250g. This includes autopilot and GPS. It's designed to have external servos and a shifting wing placement since it will have various payloads like a mini VGA camera. The electronics are housed nicely in the fuselage powered by a 850mAh 7.4V battery. I've removed the redundant magnetometer in the autopilot board. Still not sure on the CG placement, but from the crashed maiden test and the fact that the control moment arm is quite small, it's believed that the C.G. needs to be further aft from the wing main spar (which currently sits on the aerodynamic center).

So I've been battling to establish a simple method in mimicking rc control inputs during a sustained or coordinated turn of the aircraft. This is quite important as it's not the same as stabilizing controller which reacts to dynamic events while having a static reference. A coordinated turn has a dynamic reference which is coupled to the turn rate experienced which directly related to the speed and the roll command inputs. But since the turn rate of the aircraft can be extracted from the gyroscope measurements, it can be stated that post processing of these signals (using a low pass filter) should give an indication of whether such method can be used alongside a stabilizing controller. This is such that once a coordinated turn can be achieved even in adverse weather, waypoint tracking is closer to being realised. Amendment 15/1/2015: It was found after careful analysis of the flight dynamics of a simple aircraft that gyroscope measurements was not a fool-proof way of ...

If you want to use my graphic outside Wikipedia, and its resolution or license doesn't satisfy you, write to me: 100px (Photo credit: Wikipedia ) The radian glider took a real beating at the last crash. Although it had a 'soft' landing eventually, going through the trees was not pleasant the foamy airframe . since it wasn't covered, indentations can be seen all over the aircraft.

Although it was a bittersweet moment when the Radian glider took off (my own airframe had a disastrous crash), it felt really good seeing that glider gracefully fly through the skies. After the repairs I had to make on it, I realise that motor has a pitch up moment on the airframe causing the glider to quickly gain altitude but loosing forward speed. That will have to be remedied.

I Although I now have a Radian glider. It's quite difficult to find open places where you're able to practice your flying. So i decided to design a new airframe that will be able to keep my flight hours up without having to travel far. The aim was to make a cheap. light and yet strong powered plane that, if needed, would be able to carry the autopilot board. The airframe was made of foam core , 160gsm board paper, packaging tape and dowel sticks.

The inevitable had to come... Introducing the Radian Glider. This will be used as the ultimate airframe to put my autopilot to the test... But for now, I will have to get my flight skills up with a self made trainer ( with foldable prop). I will have to make use of a public park for now until I'm ready to join a flying club. Let the games begin!

The coolest thing happened last night. Many posts I've seen tell you that if you want to add shear strength to your foamie aircraft, you need to pray adhesive prior to covering it with packaging tape. I'm afraid to say... that's half the truth!!! You see, eventhough the tape will stick for a while any sharp flexing of the wing during flight will cause the rape to start stretching because it detached from the foam surface. This caused the stretched tape to wrinkle up and no longer add structural strength to the foam. So how do you prevent this from happening? Add heat. You see, with heat the glue of the adhesive tape is activated and the foam surface slightly softens to give you a strong bond. So what temperature should one use? Well I did this part by trial and error. I found that a temperature of 80 degrees was sufficient to activate the adhesive and foam sticking to each other. I still feel that using a spray adhesive over the foam area gives a better chance...

So I've finally arrived at a time all aircraft engineers hope to get... Maiden flight. But I've had too many experiences where the maiden flight is all but over in a matter of seconds becauseI was too eager to "free the bird". The end result... A disgruntled soul wishing it had been more patient. I've learnt my lesson (with my wife's mentoring) to be more methodical and pragmatic about my approach to the maiden flight. Since I don't have the luxury of wind tunnel testing of the wing and the airframe, the only reliable weapon in my arsenal was... Calculations. To be more specific, weight and balance calculations and measurements. After using AutoCAD, a weight balance spreadsheet to calculate the estimated (emphasis on "estimated") center of gravity in relation to the wing mac (mean aerodynamic chord), measuring the actual cg will all electronics included was the next (and hopefully) final step. It must be said that prior to this step I reali...