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Showing posts with the label Unmanned aerial vehicle

The war against the blue-green algae

We've reviewed a document on the impact of the blue-green algae on the irrigation of the agricultural farmlands.  Our investigations follows the trend of the bursts of blue-green algae is the dams using for livestock and plants which has caused many illnesses to the farm workers and their families specifically in small-holding agricultural areas. So we've decided to undergo experimental research into the application of a low-cost drone solution for the analysis, prediction and the eventual eradication of the blue-green algae in dams which has a direct impact in the production yield of the both animals and plants. This research will comprise of the development of the remote sensing system which will generate data that will be used as inputs into a predictive model which will be used to help farmers make alternative plans well-before the blue-green algae has a financial impact the farms' operations and the safety of its workers. The proposal with be prese...

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...

Quality Assure of complete Aero model is now complete

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.

No more resisting the market trend. I'm developing a quadcopter

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!

There's hope for my drone - The FAA makes provisional drones ruling

So finally the FAA has released its take on how to regulate the commercial use of drones or unmanned aircraft on USA territory. It's mostly good news although, some companies (like Amazon) will not be too happy. The gist of the rules are as follows (copied from here ): Unmanned aircraft must weigh less than 55 lbs. (25 kg). Visual line-of-sight (VLOS) only; the unmanned aircraft must remain within VLOS of the operator or visual observer. At all times the small unmanned aircraft must remain close enough to the operator for the operator to be capable of seeing the aircraft with vision unaided by any device other than corrective lenses. Small unmanned aircraft may not operate over any persons not directly involved in the operation. Proposes a microUAS option that would allow operations in Class G airspace, over people not involved in the operation, provided the operator certifies he or she has the requisite aeronautical knowledge to perform the operation. Daylight-only operati...

So now I need a pilot licence for a 200g drone

So the game space has changed. The South Africa CAA ( SACAA ) has come out guns blazing drafting regulations regarding remotely Piloted Aircraft/System (RPA/RPS). One thing was clear, this massive chaos that growing in this country had to come to an end. Already, the general population of stakeholders in the civilian airspace have a very nonchalant attitude when it comes to safety and security. So the introduction of aviation regulations towards the growing market of drones is a much needed intervention.

Method for coordinated turn

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 ...

GPS Navigation Ground Test #2 - Heading Error Computation Algorithm

This one is going to be quite short. Yesterday was the turn of the heading error algorithm to be tested. This heading error is calculated based on the heading the between two waypoints and heading measurement from the GPS module. This error will then be fed into a the roll controller as an input for roll command to reduce it to zero. But for the roll controller to work accordingly, the input must be right and within certain bounds. Same as the previous ground test, waypoints were loaded unto the autopilot and serial debug data was monitored using my Asus TF101 Tablet. It's worth saying that I managed to get serial data output straight from the LINUX command line . So the command line integration with VIM is complete. So it takes approximately under 10sec to upload and start debugging data of the autopilot. Sweet! Anyway, it was found that the GPS accuracy should be considered at 10-12m. Anything less than that and you'll be running for trouble. That is not a real conc...

GPS Navigation Ground Test #1 - Waypoint Tracking Algorithm

So after a period of absence of over a month (feel depressed everytime I say it), I got back into the groove of things. Decided not to wait to get back on the field to test the pitch and roll autopilot and decided to start working on the waypoint tracking algorithm . The advantage of having your own home with a garden is that you no longer struggle to get a GPS lock (There's no more concrete flats surrounding us yeah!!!). So got familiar with my gear again. Also decided to buy a piezo buzzer that could be used as a replacement of the serial monitor. The aim was to increase the intensity of sound as you got closer to the next waypoint. In such a way you will know if you're going the correct way. Decided to use GPS Visualizer to get waypoints on the property. Re-formatted the points into the code uploaded it onto the controller. It must add that I managed to successfully run arduino from the linux command line and use the program screen as a serial monitor. Not only is it m...

Autopilot Flight Test #3

deadband diagram (Photo credit: Wikipedia ) Managed to squeeze another flight test on Sunday morning (the usual madness occurred afterwards). Had about 7 - 8 hand launches to test the pitch autopilot with the gyro measurements integrated in the PID loop . It was quite that some adjustment to the how these inputs are being used was needed. So after each landing, adjustment to the gains was made. The erratic nature of the control requires a deadband filter approach which would enable the airframe to settle on a particular flight path naturally (restoring motion). A crude logic was implemented and tested and seemed to work although further test will need to confirm such approach. From a kinematics point of view, it makes sense and prevents excessive servo control usage which decreases the life of the part dramatically. Once confirmation that the logic is sound, the same approach will be made on the roll and speed autopilots which will allow us in the next 2-3 weeks move towards...

Flight Data Results

We've been having quite bad (windy) weather that It has been almost impossible to get the glider up in the air to gather more flight data . But nonetheless, I managed to analyse the data that I have come to some interesting conclusion on the behaviour of the aircraft in flight. The post-filtering of the IMU euler angles prior to controller design only add approximately 4/10th of the second in lag (guestimate). The servo limiter which I set on all channels is which what a normal flight actuation is experienced (considering wind factors). It's quite clear from the graphs that GPS velocity is expected to change with aircraft pitch although the nature of the sensitivity over a 1Hz update was not expected. The noise factor in launch in both roll and pitch channels shows that an alternative method needs to be established for a take-off and landing autopilot mode. There seems to be a considerable lag in pitch servo input and pitch change. This makes sense for the fact that t...

Autopilot Flight Test #2

So I got some flight time under my belt yesterday. I must say there's nothing better than seeing your flying skills improve with time ( I can't wait to get more batteries so I can get my heli in the air as well). Anyway, back to the glider autopilot . Managed to get the roll autopilot to stabilize the aircraft which was a great feat. Although because the glider is inherently unstable during banking (due to the battery pack sitting on top of the wing) the roll autopilot relies heavily in controlling the rates produced by the aircraft. This is still a problem as roll rate doesn't yet have a strong influence in the control loop . The same can be said about the pitch controller (which I had to land the aircraft, upload new code and launch again). Due to the lack of control on the pitch rate, the phugoid mode of the aircraft is activated and the aircraft goes into an unstable dives which eventually would cause a crash. The use of the safety switch mechanism logic has ...

Initial In-flight Testing of autopilot SUCCESS!

Depicts a traditional PID controller. (Photo credit: Wikipedia ) I'm such an exciting right now. It's been over a year of putting this UAV glider with custom autopilot and electronics together and now we're at the pivotal stage. In-flight testing of autopilot and GPS waypoint tracking!! Decided to go for a flight test on Sunday morning before church (around 7am) eventhough I was performing the church band that morning (crazy I know). It was bitter cold but decided to push through. I must say that I realised that I need a small collapse table/stool to setup the instruments instead of the wet/moist ground. I was great to see that the transmitter code works as expected. There was no lag in the transmission of signals from transmitter -> autopilot -> servos. The turning of aircraft with rudder and elevator control was smooth and consistent. It was refreshing to see that the filtering algorithm worked well. Decided to test the roll autopilot first, this...

FAA can’t regulate small RC aircraft as “drones,” judge rules | Ars Technica

FAA can't regulate small RC aircraft as "drones," judge rules NTSB judge strikes down $10,000 fine against man for unlicensed "commercial use." Raphael Pirker prepares to launch his " FPV " remote controlled plane in New York City in a video he posted in 2010. http://vimeo.com/17351140 In 2011, Raphael Pirker used a RiteWing Zephyr II  remote-controlled flying wing to record aerial video of a hospital campus for use in a television advertisement. That act resulted in the Federal Aviation Administration issuing a fine to Pirker of $10,000 for that commercial use of an unmanned aircraft. But now an administrative judge with the National Transportation Safety Board has struck down that fine , contending that FAA regulations can't be applied to the styrofoam drone Pirker flew.