Collision sensors - do they detect a solid object that is approaching the drone, rather than just the other way around?

[outermagnolian]

I want to film a boat as it approaches a hovering drone, then glide up the hull as it passes. I wonder if the collision sensor will help keep me from colliding with an object that is moving toward the drone?

Also curious about techniques for hovering over waves in the water, and whether the sensors will detect an approaching wave crest that's higher than expected.

 

[CanadaDrone]

As for your first question, yes the sensors also detect something coming towards it - you can test this yourself while walking towards a hovering drone. It *should* work, but the rule of thumb is never rely on the sensors 100%. They are there primarily as a failsafe, not so much as a flight tool. It would be best to plan the flight as if you didn't have any sensors at all, rather than trusting them implicitly.

For your second question, the sensors cannot be trusted to deal with water. Altitude is controlled by a barometer so that part is OK but from an obstacle avoidance point of view, water is specifically mentioned in DJI manuals as something you can't trust the sensors to see, so use extra caution there and make sure you're well above the waves. Also, you REALLY don't want any saltwater spray on the drone, so I would keep it far away from any waves regardless. Especially if it's windy, you might be surprised what ends up with salt spray on it.

 

[dozzn]

Also for your first question, this may work as long as the boat is gone slow. Imagine if you tried this with a fast moving vehicle, the drone wouldn’t be able to get out the way soon enough. So keep speed in mind.

Also, your method may not create a nice smooth video like it would if you were using the controller. Why wouldn’t you be using the controller instead of relying on the sensors to create this video?

Either way, good luck to you!

 

[Phantomrain.org]

I want to film a boat as it approaches a hovering drone, then glide up the hull as it passes. I wonder if the collision sensor will help keep me from colliding with an object that is moving toward the drone?

Also curious about techniques for hovering over waves in the water, and whether the sensors will detect an approaching wave crest that's higher than expected.

They will however < The problem with all the sensor related accidents is the speed at which the Drone Sensors need to compensate for and if you get that wrong , its going to crash as we have seen posted many times.

As far as the waves , yes we have tested this but again it depends on your speed going over the water.
and because of that its risky. The Sensors need a faster chip to process faster and were not there yet.

You might want to consider getting a Rescue jacket and having some fun with that on the water or at least to safe guard your flight for your client.

Phantomrain.org
Gear to fly in the Rain. Land on the Water and Negotiate the waves.

 

[GadgetGuy]

I want to film a boat as it approaches a hovering drone, then glide up the hull as it passes. I wonder if the collision sensor will help keep me from colliding with an object that is moving toward the drone?

They might "help" but they can't stop it. The collision sensors only work up to a certain speed for stationary objects based upon how far away they are. When the object to be avoided is also traveling at speed towards it, the combined speed of the two is what must be used. As long as the hull is approaching the drone hovering in place at less than the maximum speed for OA, it will detect, but it still can't stop the hull from running into you, because the drone's OA is based upon still objects that can be avoided by stopping or flying around them. Stopping will lead to a collision, and flying around likely won't work if the hull is fairly wide.

Birds flying at the drone have their own OA, which is far better than the drone's!