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 But what will it take for drones to impact a traditionally outdated, low-profit-margin civil works industry through the use of technology?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...

When will I fly again? I've been asking that question for a while now. After that expensive and silly mistake of loosing my Blade 300 CFX to some uncalibrated mass balancing, the wind of excitement was whiffed out of my spirit. I must say, this has allowed me to refocus my energies on the helicopter simulation model and how it should be modeled such that the research of the neural network algorithms could be easily prototyped and embedded into an autopilot software suite for HILS and flight testing. I must say, I feel like I've made quite a bit of progress on this front. Even though my spirit is itching to get something flying in the sky, the notion that I'm getting closer to creating a simulation environment where these algorithms can be tested, explored and refined for flight testing. I'm also grateful that during this time, my company has agreed to fund my research and I now the ability to procure the items that I need to properly get this research off the grou...

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.

The second part of the HILS was a functional test mainly to observe the functioning of the OpenLog board while the IMU and the servos were running. The logging was set at 38400 bps. The aircraft was moved in pitch, roll and yaw to simulate actual flight. The motor was turned on (without propeller attached) to Success Criteria - The logging should not have a loss of data and all IMU and servo variables should be recorded at a rate is for approximately 50hz. Results:  The figures below show that logging was capable at an approximate rate of 50hz. This will be tested in the field prior to the first logged flight.

As mentioned before, the aim of this test was to show that the autopilot board could relay power to the Receiver for servos to work. The InPins of the board connected all Rx signal lines (motor, elevator, rudder, switch (explained later)). The OutPins of the board had the ESC signal line and the corresponding servo signals (elevator and rudder). This configuration could be changed in the future in the event that ailerons are used (different test aircraft). Success Criteria - Displaying transmitter signal pulses coming into the InPins showing on the Serial Monitor.   Results: - The connection test worked albeit for a lengthy debugging exercise. The switch pin on the transmitter was able to enable or disable servo control.The figures of the results are shown below:

So having concluded the first few flight tests and achieved a aircraft platform that will be suitable to test the first version of the autopilot, the time came to start the HILS (hardware-in-the-loop simulation) phase. The first step was to make sure that the ESC (electronic speed controller) will be able to supply current and the motor could still be controlled by the transmitter.  The next step was to connect the Rx and Tx to the autopilot board and have the display of signals coming to the board via the Serial Monitor. These inputs will in turn be converted to servo object angle inputs. The reason this is required is two fold: The Arduino IDE already has a servo library. So converting the pulses coming from the input channels to servo angles will be transmitted to the servo). The simplicity of this route will enable easy debugging in the event improper relaying of signals does not occur. The end goal of the HILS test is to establish a level of confidence that the...