A fun theoretical question.

[rmb]

Can you take off and fly inside a moving vehicle? i.e. If you are traveling in a train going 80 mph and attempt to take off inside, will your drone rocket backwards into the wall at 80 mph?

 

[SpinItUp]

I'm waiting for the demonstration video of the decapitation when a metal box screws up the GPS.
Edit: Why! just why!

 

[Ken K]

Can you take off and fly inside a moving vehicle? i.e. If you are traveling in a train going 80 mph and attempt to take off inside, will your drone rocket backwards into the wall at 80 mph?

Here's my guess.
Assuming you can't get a satellite fix in the train (therefore no gps) the constant speed of the train has no bearing. You would have to fly in Vision mode, Consider yourself in a car at a constant speed.
If the train accelerates or decelerates the drone would move backward or forward relative to the rail car. Consider how you move forward against the seatbelt in a braking car or back against the seat if rapidly accelerating.
If you were on a flatcar or a rail car with no roof, you would get a satellite fix and my guess is that your drone would splat against the first solid object to the rear.
Or maybe some other scenario altogether.

 

[sar104]

Here's my guess.
Assuming you can't get a satellite fix in the train (therefore no gps) the constant speed of the train has no bearing. You would have to fly in Vision mode, Consider yourself in a car at a constant speed.
If the train accelerates or decelerates the drone would move backward or forward relative to the rail car. Consider how you move forward against the seatbelt in a braking car or back against the seat if rapidly accelerating.
If you were on a flatcar or a rail car with no roof, you would get a satellite fix and my guess is that your drone would splat against the first solid object to the rear.
Or maybe some other scenario altogether.

That's basically correct. In P-GPS mode the drone has three mechanisms to help it fly - GPS position/velocity data, VPS and inertial measurements:

If it has GPS data then a moving vehicle will be a problem because it will try to remain stationary.​

​

VPS isn't a problem because it will determine position relative to the vehicle, independent of the vehicle motion.​

​

Inertial guidance will work fine but only if the vehicle is moving at constant velocity (speed and direction) and not rotating, since the accelerometers detect changes in speed and direction and the rate gyros detect rotation.​

​

The only other constraint would be that the air pressure inside the vehicle would need to remain constant to avoid vertical position corrections.​

In ATTI mode all that would matter would be constant velocity and pressure, although the pilot could correct for changes in those - at least the FC wouldn't interfere.

 

[Ken K]

In keeping with yhe "fun" part of this thread, if you are going to try this be sure to calibrate your drone's compass first!

 

[RayOZ]

Sounds like an accident waiting to happen.
Remember 2 important rule:
1. Video recording on or it didn't happen
2. Safety fir.., nah rule 1 should be enough.

 

[sar104]

Sounds like an accident waiting to happen.
Remember 2 important rule:
1. Video recording on or it didn't happen
2. Safety fir.., nah rule 1 should be enough.

I think it's just a thought experiment.

Here - hold my beer and watch this....

 

[rmb]

I think it's just a thought experiment.

Here - hold my beer and watch this....

Yea, this was totally for fun to hopefully give us all a break from "crashed my drone", "had a flyaway" and "DJI sucks

Thank you all for humoring me. And yes, if there was a satellite/GPS signal fix, "splat" would be the right answer.

 

[choo choo]

Ken Heron (see you tube) did film his phantom from a moving vehicle, I cannot remember the results, (he still has all his fingers so I think it ended happily) but if anyone has a spare moment they might like to look at it.

 

[SpinItUp]

This 1 @choo choo
Keny of the Heron

 

[Goldengate98]

LOL. Makr sure no one is behind the drone when you takeoff!

 

[vanderzyde0]

I would think that if you start from a train (or a moving van like in the video) that is already traveling fast that the drone should sense from the gps that this is some sort of gps error and refuse to fly or switch to ATTI mode. From a programming perspective this is what I would program into the flight control software.

 

[theDRONEranger]

So, if you are in an enclosed vehicle, at 75mph, and you hold a tennis ball up on the interior roof and let go, what happens?

 

[FoxhallGH]

Can you take off and fly inside a moving vehicle? i.e. If you are traveling in a train going 80 mph and attempt to take off inside, will your drone rocket backwards into the wall at 80 mph?

Bit inconclusive, but the drone in a train experiment has been done already! ...

 

[Ken K]

So, if you are in an enclosed vehicle, at 75mph, and you hold a tennis ball up on the interior roof and let go, what happens?

Or.......
If you are in an enclosed vehicle, at 75mph, and you spill your fresh cup of HOT coffee onto your lap, what happens?

 

[Goldengate98]

If the drone’s forward velocity can match or exceed the speed of the train, no problem. When he stops the drone in the video it looks like it flying backwards when he catches it, but it is then moving slower than the train (and the pilot).

 

[rmb]

Or.......
If you are in an enclosed vehicle, at 75mph, and you spill your fresh cup of HOT coffee onto your lap, what happens?

Well in fairness you are talking about gravity and relativity. Where as I was talking about the technology associated with the gps and if the moment the legs left the ground would the drone attempt to hold gps position.

 

[Bobby Brown]

You would be transported back to 1954 upon release of the Drone!!

 

[sar104]

I would think that if you start from a train (or a moving van like in the video) that is already traveling fast that the drone should sense from the gps that this is some sort of gps error and refuse to fly or switch to ATTI mode. From a programming perspective this is what I would program into the flight control software.

I agree, but I don't think that's how it was implemented. There have been numerous examples of takeoff from moving boats, and the aircraft immediately attempts to hold position.

 

[sar104]

Bit inconclusive, but the drone in a train experiment has been done already! ...

That's not in a GPS mode. A Mavic in ATTI mode would behave like that.