Couldn't Fly Forward. Was this Obstacle avoidance?

[Chrislaf]

Need some help figuring out what happened during a flight today. I was out flying in an area that I have flown numerous times (Launched on ice just out from a beach close to a sailing club). I was using Litchi to test out doing a pano with AEB and went to fly the Spark to position it in front of the sailing club but the Spark would not go forward. I am wondering if this was the obstacle avoidance getting confused by the sunlight. It was a midday sun which I have flown in many times in this exact location but due to recent mild weather, the ice was like bumpy glass and very slick (no snow).

Here is the flight log. I have looked over the log but there are no messages about obstacle avoidance, only a few messages indicating the downlink was briefly lost.

I was not really worried, but I just want to figure out why the Spark would not go forward. I have a Phantom 3 Standard (no obstacle avoidance sensors) and flew it immediately after the Spark flight in the same area and did not have any problems with it, so that is why I am assuming that the Spark's OA was somehow involved.

Thanks for any help.

Chris

 

[rangemaster728]

Per the Spark manual, pg. 12:


3D Sensing and Vision System performance are affected by the type of surface being flown over. The aircraft will switch from P Mode to ATTI Mode automatically if neither GPS or Vision System are available. Please be vigilant when operating Spark in the following situations:
Flying at high speeds below 0.5 meters.
Flying over monochrome surfaces (e.g., solid black, solid white, solid red, or solid green). Flying over highly reflective surfaces.
Flying over water or transparent surfaces.
Flying over moving surfaces or objects.
Flying in an area where the lighting changes frequently or drastically.
Flying over extremely dark (lux < 10) or bright (lux > 100,000, e.g., towards sunlight) surfaces. Flying over surfaces without clear patterns or texture.
Flying over surfaces with identical repeating patterns or textures (e.g., tiling).
Flying over small and fine objects (e.g. tree branches and power lines).
Flying at speeds of over 6.7 mph (10.8 kph) at 2 meters above the ground.

I’ve had this occur as well...just check your surroundings to make sure things are safe, then put the Spark in Sport Mode to move until you’re out of that situation...

 

[Chrislaf]

Thanks for your reply rangemaster. I think the problem was a combination of the slick ice and the sun and it’s reflection on the ice. I did switch to Sport mode with throttle full forward (see 5m 20.6s) and there was no difference. I still could not go forward. I also am aware of how surfaces can affect VPS. I was about 13m above the ice which should have not affected VPS.

Chris

 

[rangemaster728]

One other thing to try is rotating 180 degrees and backing up...that takes the forward sensors out of the equation....just an idea.

 

[Chrislaf]

I didn’t try backing up but I did try flying sideways with the camera pretty much opposite the sun and that didn’t work either. It was like there was a wall there. This is an area I have flown in almost weekly. The only difference that day is the ice was shiny like glass.

Chris