Since the last test, Brian purchased landing gear and reflective film, and we attached them to the 'copter. The landing gear consists of four legs and a central hub: the long legs would prevent the kopter from tipping, and we attached them to the existing landing gear with tape. However, this presented a problem, in that as the four legs flexed to absorb an impact, the hub would be pushed upward, and collide with the camera mount. Landing more gently would therefore be essential.
As part of the package, Aerobot provided with a small camera which could be mounted on the 'copter. It connects to a 5.8GHz transmitter, powered by a 11V LiPo battery which we mounted to the 'copter with sticky velcro. On the ground side, we had a 5.8GHz receiver, which has two analogue AV-out ports. One would usually pipe these to a TV, or a set of First-Person-View (FPV) goggles, but these had not yet arrived. There was no battery included for the receiver, so we had to run it from a 12V battery we had in the lab, originally intended to be used by the Tiny Radio Telescope exhibit. I emailed Aerobot asking where the battery for this receiver was.
Since we have neither a portable TV nor the goggles, we needed buy an AV-to-USB converter, so that my netbook could stream and record the video transmitted from the 'copter. I tested this in the lab and got a reasonable signal, once I set the receiver to channel 1. On the USB capture software, I had to use NTSC_M.
For this flight, I was assisted by Brian Crosse and a work-experience student, Ace. We wanted to test the landing gear and see if the reflective film had improved the visibility of the orientation, and to see if we could capture any streamed footage from the small video camera.
Weather was sunny, 38C, with a 10 knot easterly wind.
We plugged in the video transmitter and camera, and checked that the footage was being received on the laptop - it was surprisingly hard to tell given the extremely bright sunshine! I placed the 'copter in the same position as before - 10m to the east of my position, with its nose facing away.
Flight start 14:15 WST
I throttled up and took off, and we attempted to record some footage. Ace also used an HD video camera (a Sanyo Xactic HD2000) to record the flight. I brought it up and again in an arc around us; I then landed it. The landing gear made it much easier in terms of tilt, but it was difficult to land gently enough to avoid hitting the camera mount against the hub.
Flight end 14:17 WST
Flight start 14:19 WST
We looked at the footage but all we could see was grass! So we adjusted the tilt on the camera and tried again. This time I put the kopter into position/altitude hold and yawed it around so that we could wave at it. The reflective foil was clearly visible and gave a much better impression of the 'copter's heading. I kept flying for three minutes, since there was no real time constraint, and I wanted to continue improving my skills at the controls.
Flight end 14:22 WST
Flight start 14.25
I took off again, but quite quickly, the transmitter started to beep; I looked at the MX-20 and it was showing the message 'Compass Error'. I brought down the 'copter and nothing appeared to be wrong. We moved it back to its initial starting position and let it sit for a few minutes, in case it had overheated.
Flight end 14.27
Flight start 14.33
I took it up again and flew for a bit longer, trying some nose-first flying and again testing the 'come home' functionality. It was very pleasant flying, as the wind was absolutely non-existent, and the copter felt responsive and easy to control.
Flight end 14.37
Flight start 14.40
I put it into PH/AH and was explaining some of the controls to Ace, demonstrating tilting it to the left and right. Then the LEDs began to flash and the 'copter made an urgent beeping sound. We had had this problem in the lab when we were indoors, but not outdoors. However the day was extremely hot and quite still, and we'd been flying for quite some time, so I thought perhaps the 'copter was overheating. I brought it down perfectly, and went over to check if it was ok. Everything seemed fine but we decided to cease flight for the day.
Flight end 14:44
After the flights we looked at the captured footage, and found that the transmission quality seemed quite poor, and the framerate low. Unfortunately the battery on the transmitter had almost entirely discharged, so it was difficult to tell whether the problems were just from low battery or from the whole set-up.
When I got back to the lab, I charged the battery and then tried recording footage around the lab again. I found that if I recorded to the netbook, without it being plugged in to the mains power, the framerate was sluggish, but that if I plugged the netbook in, the framerate was fine. Evidently the CPU's power-saving features meant that it was too slow to be able to de- and re-code the AV input quickly enough.
Lessons
As part of the package, Aerobot provided with a small camera which could be mounted on the 'copter. It connects to a 5.8GHz transmitter, powered by a 11V LiPo battery which we mounted to the 'copter with sticky velcro. On the ground side, we had a 5.8GHz receiver, which has two analogue AV-out ports. One would usually pipe these to a TV, or a set of First-Person-View (FPV) goggles, but these had not yet arrived. There was no battery included for the receiver, so we had to run it from a 12V battery we had in the lab, originally intended to be used by the Tiny Radio Telescope exhibit. I emailed Aerobot asking where the battery for this receiver was.
Since we have neither a portable TV nor the goggles, we needed buy an AV-to-USB converter, so that my netbook could stream and record the video transmitted from the 'copter. I tested this in the lab and got a reasonable signal, once I set the receiver to channel 1. On the USB capture software, I had to use NTSC_M.
For this flight, I was assisted by Brian Crosse and a work-experience student, Ace. We wanted to test the landing gear and see if the reflective film had improved the visibility of the orientation, and to see if we could capture any streamed footage from the small video camera.
Weather was sunny, 38C, with a 10 knot easterly wind.
We plugged in the video transmitter and camera, and checked that the footage was being received on the laptop - it was surprisingly hard to tell given the extremely bright sunshine! I placed the 'copter in the same position as before - 10m to the east of my position, with its nose facing away.
Flight start 14:15 WST
I throttled up and took off, and we attempted to record some footage. Ace also used an HD video camera (a Sanyo Xactic HD2000) to record the flight. I brought it up and again in an arc around us; I then landed it. The landing gear made it much easier in terms of tilt, but it was difficult to land gently enough to avoid hitting the camera mount against the hub.
Flight end 14:17 WST
 |
| Modified Octo with landing gear and reflective foil. |
We looked at the footage but all we could see was grass! So we adjusted the tilt on the camera and tried again. This time I put the kopter into position/altitude hold and yawed it around so that we could wave at it. The reflective foil was clearly visible and gave a much better impression of the 'copter's heading. I kept flying for three minutes, since there was no real time constraint, and I wanted to continue improving my skills at the controls.
Flight end 14:22 WST
Flight start 14.25
I took off again, but quite quickly, the transmitter started to beep; I looked at the MX-20 and it was showing the message 'Compass Error'. I brought down the 'copter and nothing appeared to be wrong. We moved it back to its initial starting position and let it sit for a few minutes, in case it had overheated.
Flight end 14.27
Flight start 14.33
I took it up again and flew for a bit longer, trying some nose-first flying and again testing the 'come home' functionality. It was very pleasant flying, as the wind was absolutely non-existent, and the copter felt responsive and easy to control.
Flight end 14.37
Flight start 14.40
I put it into PH/AH and was explaining some of the controls to Ace, demonstrating tilting it to the left and right. Then the LEDs began to flash and the 'copter made an urgent beeping sound. We had had this problem in the lab when we were indoors, but not outdoors. However the day was extremely hot and quite still, and we'd been flying for quite some time, so I thought perhaps the 'copter was overheating. I brought it down perfectly, and went over to check if it was ok. Everything seemed fine but we decided to cease flight for the day.
Flight end 14:44
After the flights we looked at the captured footage, and found that the transmission quality seemed quite poor, and the framerate low. Unfortunately the battery on the transmitter had almost entirely discharged, so it was difficult to tell whether the problems were just from low battery or from the whole set-up.
 |
| The best still I managed to capture from the poor-quality on-board camera footage |
Lessons
- De- and re-coding from AV to MPEG is tricky for the eeePC unless it's running at full CPU capacity -- disable power-saving features if you want to capture footage.
- Ensure that the transmitter battery is fully charged before trying to power the camera and transmitter, and see if that improves the quality of the footage received.
- Reflective foil good
- Landing gear still needs work to prevent collision with the hub
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