For the first proper test flight, I wanted to use an area with considerably more free space than the courtyard behind the office. As term had ended, we were able to make use of Curtin University's Edinburgh Oval, a flat grassy space of 150 x 200 m with no trees and good visibility.
The plan was simply to take the octocopter up and test each of its controls - yaw, throttle, and tilt in each direction. I wanted to get a feel for the controls and see what the difference was between the simulator and reality. I intended to remain in manual control for the majority of flight, test the altitude/position hold, and to keep below an altitude of 10m, within a range of 30m. Assisting me was Brian Crosse.
Weather was 34 C and partly cloudy, with a 15-knot W wind, a little stronger than I would have liked for a first flight.
Flight start 15:12 WST
I placed the 'copter about 10m east of my position, with its nose pointed away. I calibrated, took the throttle up, and brought the 'copter into the air. I tested holding its position against the wind, gently tilting it toward me. I brought it a little higher, and tilted it around in an arc to the right, adjusting the yaw once I had repositioned, so that its nose was again facing away. I then brought it around to the left again, again yawing to compensate. I put it on altitude/position hold and found it quite stable, although it did move a few meters when caught by gusts of wind. I then landed it, but found that the ground effect was quite a bit stronger than in the simulation, so the 'copter bounced a few times and tipped over, landing against one propeller.
Flight end 15:14 WST
Flight start 15:23 WST
For the second flight I wanted to take it a little further away, to begin to get a feel for how it would look when we would use it for measuring the tile beam. In the simulator I noticed that it was easy to lose track of its orientation and I wanted to find out how strong this effect was in reality. I flew the 'copter about 20m away to the East, and kept it at a reasonably low elevation. This indeed did make it hard to see its orientation, as the LED lights are on its undercarriage. I brought it up to 15m elevation in order to adjust the yaw, putting it in PH/AH again to test it. I then tried out the 'come home' functionality, which brought it back. I landed it, but was unable to prevent it tipping over again. I found that in a wind, it was actually easier to fly while in PH/AH, as if I stopped moving the controls, it would simply stay in one place, as opposed to drifting away in the wind.
Flight end 15:25 WST
Lessons
The plan was simply to take the octocopter up and test each of its controls - yaw, throttle, and tilt in each direction. I wanted to get a feel for the controls and see what the difference was between the simulator and reality. I intended to remain in manual control for the majority of flight, test the altitude/position hold, and to keep below an altitude of 10m, within a range of 30m. Assisting me was Brian Crosse.
Weather was 34 C and partly cloudy, with a 15-knot W wind, a little stronger than I would have liked for a first flight.
Flight start 15:12 WST
I placed the 'copter about 10m east of my position, with its nose pointed away. I calibrated, took the throttle up, and brought the 'copter into the air. I tested holding its position against the wind, gently tilting it toward me. I brought it a little higher, and tilted it around in an arc to the right, adjusting the yaw once I had repositioned, so that its nose was again facing away. I then brought it around to the left again, again yawing to compensate. I put it on altitude/position hold and found it quite stable, although it did move a few meters when caught by gusts of wind. I then landed it, but found that the ground effect was quite a bit stronger than in the simulation, so the 'copter bounced a few times and tipped over, landing against one propeller.
Flight end 15:14 WST
Flight start 15:23 WST
For the second flight I wanted to take it a little further away, to begin to get a feel for how it would look when we would use it for measuring the tile beam. In the simulator I noticed that it was easy to lose track of its orientation and I wanted to find out how strong this effect was in reality. I flew the 'copter about 20m away to the East, and kept it at a reasonably low elevation. This indeed did make it hard to see its orientation, as the LED lights are on its undercarriage. I brought it up to 15m elevation in order to adjust the yaw, putting it in PH/AH again to test it. I then tried out the 'come home' functionality, which brought it back. I landed it, but was unable to prevent it tipping over again. I found that in a wind, it was actually easier to fly while in PH/AH, as if I stopped moving the controls, it would simply stay in one place, as opposed to drifting away in the wind.
Flight end 15:25 WST
Lessons
- Need to improve the visibility of orientation - Brian suggests reflective plastic film of the type used in model rocketry
- Landing in even a light wind is difficult with the existing landing gear, as the 'copter is very top-heavy and has a tendency to tip. We could attach a larger set of landing gear.
- PH/AH makes it easier to land, with the disadvantage that it's another layer of control that can go wrong, if you lose GPS or compass for some reason.
No comments:
Post a Comment