How to build autonomous indoor drones

We explain how to design and build autonomous indoor drones and what indoor positioning systems to use to track indoor drones when they are not autonomous.

Though we focus on indoor drones and on autonomous drone indoor navigation, the drone positioning system works perfectly well outdoors as well. It just requires outdoor-protected beacons, for example, Super-Beacons-Outdoor.

Indoor positioning system for drones

Recommended Marvelmind configurations for drones

When you are very new to the Marvelmind Indoor “GPS” system and are unsure what to choose, get the Starter Set Super-MP (MP stands for multi-purpose), which Starter Set Super-MP (MP stands for multi-purpose), and that would be your safest choice.

For more specifics, study the recommended options below.

Overall the best and the safest choice when you are not sure what to choose or what exact experiments you will run, but you want to have the greatest flexibility and performance simultaneously.

It is the best choice is when you need to connect to PixHawk as well because two pins for the connection to PixHawk are readily available on the Super-Beacon as well. See more.

Configuration:

https://marvelmind.com/product/starter-set-super-mp-3d/

https://marvelmind.com/product/super-beacon/ – additional mobile beacon for the Paired Beacons configuration to have both location and direction. See more about the Paired Beacons demo

The set is designed for micro-drones (<100g) because the Mini-TX mobile beacon is tiny and light. The set can also be used for larger drones, but the ultrasonic pulses (and the range) on Mini-TX is smaller than the same of Super-Beacons or Beacons HW v4.9. It is easily 15-20m, which is sufficient for most real cases.

Mini-TX is excellent for tracking. But it is not easy to connect with PixHawk, for example. Super-Beacons are recommended instead.

Configuration:

https://marvelmind.com/product/starter-set-nia-03-smalldrone

An advanced version of the “Starter Set Super-MP-3D + Super-Beacon – Location+Direction on the drone” option.

 

The Precise-Z, which physically consists of 2 additional stationary beacons on gives a possibility to have precise Z coordinates in all ranges of Z.

See more:

Placement Manual – Precise-Z slide
Video explanation about Z and placement of beacons

 

Configuration:

https://marvelmind.com/product/starter-set-super-mp-3d/

https://marvelmind.com/product/super-beacon/ – additional mobile beacon for the Paired Beacons configuration to have both location and direction. See more about the Paired Beacons demo

https://marvelmind.com/product/super-beacon/ – additional stationary beacons for Precise-Z feature

If you want outdoor protection, then we don’t have ready sets. But you can gather the set by replacing Super-Beacons with Super-Beacons-Outdoor and Modem v5.1 with Modem v5.1-Outdoor.

If you are not sure, just send us an email to info@marvelmind.com with detailed questions and we will be happy to help and advise.

Using Marvelmind Indoor "GPS" for drones and quadcopters

Marvelmind indoor positioning system or Marvelmind Indoor “GPS” is widely used for drones or quadcopters in many different ways:

  • Guiding autonomous indoor drones and outdoor drones. Outdoor drones – guiding for “the last mile,” which is about 30m
  • Tracking indoor drones
  • Automatic indoor and outdoor drone landing or drone landing assistance
  • Warehouse inspection using autonomous indoor drones
  • Drone shows
Autonomous drone indoor

Marvelmind Indoor "GPS" supports PixHawk with ArduPilot and PX4

Marvelmind Indoor “GPS” supports both PixHawk with ArduPilot and PX4:

 

Build indoor positioning system for quadcopters properly

There are quite many, but rather fundamental aspects that have to be taken into account to fly indoors successfully:

  • Autonomous copter settings manual – basic and practical recommendations for setting up of Indoor “GPS” system for usage with autonomous copters/drones indoor and outdoor
  • Placement Manual – practical advice and examples of how to mount the Marvelmind Indoor “GPS” system to achieve the best performance in different applications and configurations
  • Help: Z-coordinates for copters – long explanation – YouTube explaining how to place the stationary beacons properly to get good Z accuracy. If you can’t use the advice because your environment doesn’t let you use the Precise Z configuration with 4+2 stationary beacons

See the Products page for different starter set options.

However, just three stationary beacons would have little resiliency against obstructions. Any occlusion of any stationary beacon – non-line of sight/hearing situation – will lead to no tracking or erroneous tracking. Ike in GPS: “no satellites visibility = no GPS coordinates = no tracking”.

Thus, we recommend at least N+1 redundancy for stationary beacons. And that is why our starter sets for 3D consist of 4 stationary beacons.

Even better is to have 2N redundancy with fully overlapping 3D submaps. That would be either 3+3 or 4+4 stationary beacons. The system would automatically choose the best submap for tracking. That kind of system is very resilient, and with proper placement of the beacons, you can fly even in complex rooms with columns, for example, without tracking issues.

The key to excellent tracking is to provide proper coverage at any flight point, i.e., the mobile beacons on the drone must have three or more stationary beacons belonging to the same submap with a clear, direct line of sight/hearing within 30m.

The proper placement is usually the key and vital to drones because they require 3D; the drones are fast, and the mistakes may be particularly costly. What to pay attention to?

  • The most critical requirement for good tracking or autonomous flight – provide a clear line of sight/hearing visibility from the mobile beacons on the drone to 3 or more stationary beacons
  • Don’t rely on magnetometers indoors. Use the Paired Beacons configuration for Location+Direction
  • Place stationary beacons so that angles from the mobile beacons to the stationary beacons would be 30 degrees or more. See a longer explanation in the video
  • Use the Precise-Z configurations when not possible to achieve proper angles to the stationary beacons otherwise

Examples of precise indoor positioning and navigation for drones

Precisely (±2cm) tracking DJI Phantom quadcopter indoor in 3D (XYZ)

  • Precise tracking in X,Y,Z (XY view + XZ view + YZ view)
  • Raw data and post-processed data from Dashboard’s Player – notice that today the same is available not in the post-processing but in the Real-Time Player
  • The DJI ecosystem is closed, at least, for the Phantom and Mavic series. Thus, it is possible to track the Phantom but not fly autonomously indoors (without deeper hacking)
  • Learn more about Flying DJI drones autonomously indoor

Precisely (±2cm) tracking DJI Phantom quadcopter outdoor in 3D (XYZ)

  • Precise (±2cm) tracking in XYZ (XY view + XZ view + YZ view) – the same as above, but outdoor
  • The same Precise-Z configuration consisting of 4+2 stationary beacons is used in this demo and above. See more in the Placement Manual
  • Learn more about Flying DJI drones autonomously indoor

Fully autonomous flight indoor

  • Small copter is flying fully autonomously relying on Marvelmind Indoor “GPS”

Indoor tracking small and micro-drones

It is possible to track even micro-drones (less than 100g) with the help of Mini-TX beacons.

Starter Set NIA-SmallDrone is specifically designed for this kind of drones.

The minimum configuration for the drone tracking would be any NIA set with 3D capability. For example, three stationary beacons + 1 mobile beacon + 1 modem and Non-Inverse Architecture (NIA) or Multi-Frequency NIA (MF NIA) would already be OK for the drone.

Drones for warehouse inspection

Using drones for warehouse inspection is pretty popular – finding lost pallets, security, etc. Yes, it is a doable task but very complex in practice:

  • Very challenging environment in general
  • Drones fall and break => high cost of error
  • Drones are potentially dangerous to fly and to challenging to develop and use

Nevertheless, the solution is up-and-coming. Thus, drone builders or builders of warehouse systems use our indoor positioning system for such solutions. In the video, we explain the peculiarities of the environment (narrow aisles and high shelves), how the peculiarities affect accuracy, and how to build the system optimally.

Autonomous landing platform for drones

It is possible to build an autonomous landing platform for a drone. It can even be a moving one:

  • You place four stationary Super-Beacons facing up on the edges of the platform. The larger platform – the better accuracy of the distance
  • You put two mobile Super-Beacons facing down

Drone flies using regular RTK GPS or even GPS when it is far and up to 30m from the platform. It is locked to the Indoor “GPS” coordinates and is landing based on these coordinates. As mentioned, the platform may be static against the Earth or moving. It doesn’t matter for the drone. So, you can precisely land on a moving vehicle, for example.

Autonomous flight by our customers

Autonomous flight by our customers with Pixhawk + Marvelmind

"Can I fly DJI Mavic autonomously indoor?

It is easy to track DJI drones indoors. However, flying DJI drones autonomously indoors is more complicated.

Learn more about Flying DJI drones autonomously indoors.

If anything is unclear, contact us via info@marvelmind.com