Swap Drone's battery autonomously?

[dean805]

Hey guys,

I'm very new to drone photography. I got interested in this as I was trying to use my DJI Matrice 100 to film my sister's wedding. It was astonish to me that the drone can only fly for ~25-30 mins before it has to come down and swap the battery.

As an engineer, one thought that came to my mind is to develop an autonomous battery swap station; which I can set the station on one side, set the drone into autopilot mode which it can land and swap battery when the battery runs out? This way, would it be like having a second wedding photographer?

What do you guys think? Is this idea something worth pursuing?

 

[ac12]

It is all about compromise.

Battery capacity is directly related to weight.
More capacity = more weight.
More weight = less lifting capacity and less flight time. So a 2x battery capacity is less than 2x flight time.

Bigger drone/quad, larger battery, longer flight time = more expensive.

No.
The problem is the battery compartment has to be easily accessible, including opening and closing the compartment door, the battery has to be easily removed and installed, the battery contacts need to be such that it will make contact simply by sliding the battery in.
IOW this has to be designed in by the manufacturer. I likely would be difficult to retro fit the battery.
IF you are lucky, the manufacturer may have designed the drone such that it might be possible to retrofit the battery.

Second item is cooling.
Will the motors take being run for significantly more than 30 minutes?
I recall reading that some coaxial and quads needed rest time to let the motors cool down.
You need to research the duty cycle of the motors in the drone.

So rather than battery swapping, I think you may need to swap drones.
Get a 2nd drone and a 2nd pilot.
At 20 minutes, launch the 2nd drone, and once in position and running, bring down the 1st drone to cool down the motors and swap batteries.

BTW, I hope you are not flying over people.

 

[dean805]

For Battery compartment, I was planning to come up with some hacks instead of going to manufacturer. Here is something similar to what I have in mind:
There seems to be a few example on youtube for customized drones but not for DJI drones which is where my initial idea was coming from.


Hmmm that's a good point, I wasn't thinking of the motors might need to be cool off before the second/ third run Let me dig into that more.

Appreciate your input man!

 

[480sparky]

Three issues.

1. Lack of market.
2. Expense.
3. Complication.

 

[Dave442]

As ac12 noted - multiple drones. As long as you have enough charged batteries sitting around you can have a drone up at all times.

 

[ac12]

#1 - In the video, it looks like the battery compartment is above the props.

• That is what I was talking about. He built an external battery compartment, because he likely could not get easy access to the internal battery compartment.

• Putting the battery assembly above the props, raises the center of gravity of the quad.
  How does raising the CG higher affect flight characteristics and control?
  In a normal quad, the props are the uppermost part of the quad, not any part of the body of the quad or its payload. This keeps the CG below the props, so it is easy to control
  I would like to see just how well that quad flies. And a view of the transmitter at the same time, so that I can see how much he is working the controls to control the quad.
  If the quad had electronic stability control that would make control easier.

• What does that BIG battery compartment do to the air flow. IOW, how much is the lift reduced by the obstruction of the air flow by the battery compartment?
  To compensate for less lift, you run the power higher, which drains the battery faster = less flight time.

#2 - The battery compartment itself looks like it will add a fair if not significant amount of weight to the quad.
More weight = less flight time.

#3 - That would have to be a VERY precise landing to put the feet into those 4 cups.

• If you fly manually, I would think you would waste a LOT of time just trying to land the quad into those cups, rather than just put it down on flat ground where your landing accuracy can be +/- 3 feet.
  
• If you miss the landing and tip the quad, you could break a prop. Then you loose even more time, replacing the prop.
  
• Without auto landing to a landing transmitter, repeated accurate landings will be very difficult.
• I would just land the quad on level ground, then manually move the quad into the battery changing device.

#4 - But given that particular battery configuration, you can manually swap the battery MUCH faster than with that device. Just time it and imagine yourself swapping the battery by hand. OK you could use faster mechanical devices, to reduce the slow movement times.

Interesting idea, poor execution.

 

[480sparky]

................

• If you fly manually, I would think you would waste a LOT of time just trying to land the quad into those cups, rather than just put it down on flat ground where your landing accuracy can be +/- 3 feet.......

• Hand catch at landing. Problem solved, and much faster.

 

[Destin]

................

• If you fly manually, I would think you would waste a LOT of time just trying to land the quad into those cups, rather than just put it down on flat ground where your landing accuracy can be +/- 3 feet.......

• Hand catch at landing. Problem solved, and much faster.

Manually swap the battery. Much faster; eliminates this entire problem.

 

[Light Guru]

I got interested in this as I was trying to use my DJI Matrice 100 to film my sister's wedding.

I don’t think anyone wants a noisy stone frying around their wedding. Too distracting and too much potential to crash and hurt a guest.

This way, would it be like having a second wedding photographer?

It’s not like having a second photographer at all. Over head is not the same as on the ground photographer. Plus someone will have to operate the drone, so you still need a second person.

What do you guys think? Is this idea something worth pursuing?

I think a auto battery swapping station is adding a overly complex solution to something that is already going to be problematic at a wedding.


Sent from my iPhone using Tapatalk

 

[ac12]

You need to be high enough that the prop and motor noise are zero, so that you do not disturb the wedding ceremony.

Per FAA regulations, you must NOT fly over people.
So you can only shoot at an angle.
NO gods eye view, because you will then be over people and in violation of the FAA regs.
And you have to take wind and altitude into consideration. Where will it fall if/when it looses power? If you are upwind, you may fall into the people.

Finally, if you do this commercially, you need to get an FAA remote pilot certification to fly it.

The regulations are pretty clear; either 1)hobby/recreation or 2)recreation/commercial.
If you are paid, it is commercial.

FAA Getting Started with a drone.

 

[480sparky]

Look into 'mast photography'. Basically, very very very very tall tripods. Some go up to 75' Mine will go 50. Perch a DSLR up there and let 'er go...... as long as the battery will last.