X450 Quadcopter
Improvement Notes
Following up from my first post on this project, I stumbled across my notes from last October outlining the various issues we’d experienced during the first few flights:
Video signal issues
We could only get good video up to a range of about 100-200 metres. I couldn’t tell if this was a problem with the antenna alignment or interference from the quadcopter itself. The first thing to try is cloverleaf antennas so I’ve bought a pair of those as well as making a pair - it’ll be interesting to see how differently they perform. I may also try placing the TX antenna below the main frame to see if that makes any difference.
Poor video quality
The video got completely desaturated when pointed at the ground. This is a major issue because the ground is what we’re most interested in. Admittedly the conditions weren’t ideal with the low sun of a late afternoon in October but I’m hoping for some improvements. For starters, we’ve upgraded to a GoPro clone which will hopefully do a better job of managing saturation levels. I may also experiment with a small sun hood to see if that improves things.
Lack of video recording
Upgrading to the GoPro clone will solve this. This has, of course, necessitated the acquisition of an under-slung brushless gimbal which has been the major reason for this redesign of the quadcopter body. I also had to design a new carrier for the camera as the generic one which came with the gimbal was a bit rubbish. If I can find the files, I’ll post up some details. I’ll still be keeping the FPV camera as the primary video source for piloting.
Short flight time
The initial flight time with a 2200mAH 3S LiPo was about 7-8 minutes. I’ve since purchased a 4000mAH 3S LiPo which will hopefully provide a decent increase. We’ll also be looking at pre-flight planning and experimenting with GPS mission planning software to make better use of the time we have available to us.
Poor battery life confidence
Related to the short flight time, my Pixhawk clone wasn’t able to send telemetry data to my FrSky Taranis handset via the D4R-II receiver so we had to return to base in plenty of time. I’ve since constructed a simple level-switching bridge which enables telemetry and I’ve set up some alerts so we should be able to push the limits a bit further in future.
No bystander video
We didn’t have a ground station setup for our initial flights so bystanders were watching the grainy, monochromatic video over my shoulder. For future flights, I’m hoping to set up a proper ground station with video and telemetry screens separate from my handset. I may also put the GoPro clone on a separate video transmitter.
Once the quadcopter’s back up in the air, I’ll use these notes to assess how effective the improvements have been.
Posted on 24 August 2016
