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Showing posts with the label Brushless DC electric motor

Fault Detection and Diagnosis of Drone rotor faults - Simulation

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...

Review of Drones for Good Award - Message of Hope

We stumbled on the organization that's making head waves around the globe called Drones for Good Award . Although the coveted prize money is not openly advertised, various companies have participated over the past few years such as: PrecisionHawk , LoonCopter , Drones against Tsetse and many more. We were pretty impressed especially with LoonCopter. This is drone which is capable of air, surface and underwater navigation. The aim is mainly for search and rescue and the proof of concept was demonstrated at the award. But what's more fascinating is the culture and ethos this organization promotes. The idea that drones CAN be used for good and SHOULD be used for good. This is something we at Uav4africa believe immensely . The notion that you can use technology, whether in the air or under the sea, to uplift, educate and empower underprivileged communities is beyond a nice gesture, it's calling all of us should respond to. One of our projects is to investigate...

The obvious distraction to drone flight control research - Aerial videography

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...

High Speed Videography for accurate Drone Rotor RPM estimation

So the notion that in order for me to proceed scientifically (and practically) towards the design of rotor dynamics identification algorithms that will run in real-time, I first need to model the effects of the rotor failure through experimentation. The two best ways of the doing this are (1) Buy a +R2k Tachometer and record (probably by  recording the display) the speed of the propeller with a pre-determined PWM value. (2) Use the high speed capability of an action cam (such as GoPro) and some clever algorithms to compute the propeller RPM. The latter is the cheaper (and the geekier) option of the two. The setup was such that contrast was created through the use of a black mat cloth on the setup table and painting the opposing blade of the propeller black and white (see below). A RGB (red-green-blue) adaptive algorithm was developed which would mitigate the occurrence of glares on the blade which would in turn give a false reading with the algorithm. Each frame was analyze...

Research drone airframe upgrade

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...

New miniscale aircraft concept

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).

Glider Airframe Modelling for Flight Controller design

Due to the past 2-3 months of bad rainy weather and gusty winds, I've decided that it was time that I invested in a tool that will be able to give me preliminary understanding the flight control is a scientific way . That means I will have to acquire a mathematical model of the airframe and use the current hardware to form a In-The-Loop Simulation (HILS). My approach for this will be to use DATCOM to derive aerodynamics parameters then coding the equations in C. This will then be flashed unto a separate Atmega microcontroller and will talk to the the rest of the hardware via the serial interface . The accelerometers and gyroscope values (superimposed with errors and biases) will be then form part of the output from the airframe model which in turn will exercise the flight controller and mission controller. What's not sure yet is how to test completely the waypoint tracking algorithm without using the GPS hardware. One way was to have a simulated GPS module as part of t...