Test flying an experimental uav
Over view
Test flying the VTOL with the tilt mechanisms designed in a prior blog (link). This vtol design is a tricopter with the front two motors being able to tilt and the back motor is stationary. The vtol uses a pixhawk autopilot to preform the flight controller operations. The vtol currently runs on 3 iflight xing 2814 1100kv motors with 9 inch by 5 pitch tri-blade propellers. Each motor produces a maximum of 2 kg of thrust, and the vtol has and all up weight of 2kg so it has a thrust to weight ratio of 3:1. The current operation of the vtol is without the full fuselage and espionage as those are still being manufactured.
The first flights
The first flight took place on 4/5/2020, this inital flight was not with the motors listed above, but with the motors listed in the vtol tilt mechanism blog. While the vtol was able to fly, it did not hover for long, as it was severely under powered. Being under powered lead to some unstable characteristics in flight but the proof of concept worked. A new propulsion system was ordered and installed as a result of this first test flight.
The first flight with the new propulsion system took place on 4/19/2020, which as a day with decent winds of 15-20mph. Figure 1 shows the uav in flight, testing the hovering function of the vtol.
Figure 1. A video of the vtol being tested in hover mode
Post flight Analysis
While the uav flew great it needs to be tuned dramatically on the yaw channel, as is a problem for most vtols as the increased side area, allows the wind to play a much greater roll in rotating the aircraft. Another potential issue with operation is that the rear motor will just create drag in flight, but it could be potentially used to increase the thrust of the uav. This lead to another redesign, which changed the vtol from a tricopter to a quad copter, a rendering of the hovering platform, figure 2, shows the addition of 2 more tilting mechanisms in the rear, and a reduction of the 2 tail booms to a singular boom for a v tail.
Test flying the VTOL with the tilt mechanisms designed in a prior blog (link). This vtol design is a tricopter with the front two motors being able to tilt and the back motor is stationary. The vtol uses a pixhawk autopilot to preform the flight controller operations. The vtol currently runs on 3 iflight xing 2814 1100kv motors with 9 inch by 5 pitch tri-blade propellers. Each motor produces a maximum of 2 kg of thrust, and the vtol has and all up weight of 2kg so it has a thrust to weight ratio of 3:1. The current operation of the vtol is without the full fuselage and espionage as those are still being manufactured.
The first flights
The first flight took place on 4/5/2020, this inital flight was not with the motors listed above, but with the motors listed in the vtol tilt mechanism blog. While the vtol was able to fly, it did not hover for long, as it was severely under powered. Being under powered lead to some unstable characteristics in flight but the proof of concept worked. A new propulsion system was ordered and installed as a result of this first test flight.
The first flight with the new propulsion system took place on 4/19/2020, which as a day with decent winds of 15-20mph. Figure 1 shows the uav in flight, testing the hovering function of the vtol.
Figure 1. A video of the vtol being tested in hover mode
Post flight Analysis
While the uav flew great it needs to be tuned dramatically on the yaw channel, as is a problem for most vtols as the increased side area, allows the wind to play a much greater roll in rotating the aircraft. Another potential issue with operation is that the rear motor will just create drag in flight, but it could be potentially used to increase the thrust of the uav. This lead to another redesign, which changed the vtol from a tricopter to a quad copter, a rendering of the hovering platform, figure 2, shows the addition of 2 more tilting mechanisms in the rear, and a reduction of the 2 tail booms to a singular boom for a v tail.
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| Figure 2. A rendering of the vtol mechanism for the next rendition of the vtol |
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