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Mar 28 2012

Forest Fire Videos Captured with a Hexakopter

Here are links to two videos we collected of the forest fire we flew in early March in New Jersery.  Stephen had posted previously, post here, about our experiences getting the payload to fly on the Hexakopter, a repeat of similar work from last year.

Taking video was an afterthought for the project so we only had an SD4000 on hand for filming.  I think the video quality would have been a lot better if we had the GoPro.  Despite the wiggle and bluriness of the video, it is still possible to see the smoke lines set by the fire managers (see images at left) and there are places in the afternoon video where I think you can even see fire.  Note that these videos were taken pointing about due west, so I believe the shots from later in the day appear darker due to exposure compensation.

Video from about 12:45 - 12:55 local time: http://youtu.be/q3S3V3212bo?hd=1

Video from about 15:45 - 15:55 local time: http://youtu.be/GQHh2LX_ad8?hd=1

Feb 23 2011

Hexakopter Suspended Payload Tests–Results

The results of our Hexakopter payload tests were better than expected!

You can see a few clips from the test flights here: http://www.youtube.com/watch?v=OZlamfvl3VU

Basically, we suspended a 1.5lb weight from a metal cable, dangling about 12 feet below the Hexakopter.  We tested take-off, landing, auto-controlled hover with GPS and altitude lock and waypoint flying.

We found that the onboard computer can fly the unit with payload better than I can and that it performs very well at staying balanced despite a pendulum effect from the payload.  The unit appears to dampen this effect after a few seconds and in periods of calm wind the whole rig appeared virtually motionless.  In an auto-hover test, the unit lasted about 12 minutes before reaching the battery limit, it is expected that this time would be a bit less in a real flight.

Overall, a successful experiment and a great day to be out in the field!

Feb 17 2011

Hexakopter Suspended Payload Tests

How well will a Hexakopter work at carrying an instrument payload suspended several meters below?

That is the question we will be trying to answer in the next few days as we get ready for some work for the Forest Service. The goal is to suspend an instrument payload several meters below the Hexakopter on a light-weight metal cable. The payload will weigh about 1.25 lb (0.56 kg) and needs to be far enough away from the Hexa to avoid the effects of downward prop wash. The payload and Hexa will be flying through smoke and we want the instruments to be unaffected by the Hexa itself.

I purchased some 1/16" (~1.6 mm) braided metal cable, some ferrules and some clips from the local hardware store to build the suspension system. I am going to use a 'calibrated' water bottle in place of the instrument payload for weight.

I am going to test:

1) At what distance below the Hexakopter will the effects of prop wash be non-existent / negligible? This will be done in the field by flying a Hexa above a pole with flagging tape on it. This distance will be referred to as X meters.

2) Can the Hexakopter fly in manual and auto mode with a 1.25 lb payload suspended at X meters from a 1/16” metal cable? This will be tested by performing take-off, manual flying, auto-hold, auto-waypoint flying, and landing with the payload attached. Results will suggest total success or a range of flight performance. It is expected that wind will play a significant factor.

3) How long can the Hexakopter fly with the payload attached? This will be tested by first getting the Hexa to altitude with payload and letting it to hover until the battery is at the minimum safe capacity. Then, with a fresh battery installed, it will be tested by flying a simple ‘back and forth’ route over the flight area to simulate increase battery demand.  It is expected that there is a great potential for pendulum affects to occur during flight.

Stay tuned for some results!

UPDATE: I forgot, one of the main Hexakopter videos shows Holger doing his insane Hexa flying witha 1kg soda bottle suspended from below.

http://www.youtube.com/watch?v=gvH2f-AewX8&t=8m0s