A visual positioning system for precise indoor navigation

We have been testing one of our first products based on video-signal processing: the Visual Positioning System (VPS) code-named Dragonfly.  We anticipate that this system can be used by autonomous mobile vehicles to determine their location in 3-dimensions, enabling indoor navigation.  What makes it different?  Several features: the new product requires minimal, uncomplicated setup, it is very simple to extend and modify, provides better than 4 inches accuracy, and can be deployed outdoors as well as indoors.Visual Positioning System paper beacons demonstration

“Paper beacons”?  Really?  What is that?  Well, the definition of the word “beacon” says “a light or other visible object serving as a signal, warning, or guide…”.  “Paper beacons” extend the meaning to designate visible physical markers that identify specific geographic locations.Video Positioning System marker

This is at the core of VPS Dragonfly design. Imagine deploying throughout a venue a series of 2-dimensional markers that encode the 3-dimensional geographic coordinates of where they are placed.  Designed as a simplified QR code, these “paper beacons” encode latitude, longitude, altitude (off the floor) and level (first floor, basement, etc.) of where they are placed.

The markers’ image can be generated with a regular printer. Images can be transferred to any 2-dimensional medium, such as metal engraving for outdoor use.

Obviously, the 2-dimensional “paper beacons” (that is, markers) must be placed at a designated height, each at the precise location they identify.

Once the markers are in place, you are ready to go. No wiring, no power sources and no batteries to worry about.

How it works

VPS software decodes camera input that captures marker images. As described, images encode location coordinates, but there is more to it: the angle at which markers are read helps determine height and distance to them, which yields a 3-dimensional location with accuracy better than 4-inches.

Note that all computations are performed client-side, enabling applications running on mobile devices to obtain their 3-dimensional locations anywhere in a venue.

System deployment

Naturally, correct system deployment is essential: the placement of each marker, including its orientation, must be planned and performed correctly.  Deployment consists in placing marker images at the right spots in a venue.  Note that marker orientation is specified to ensure any camera processing its data gets the correct angle and heading.

To aid in deployment, location coordinates, height and orientation are displayed in human-readable form at the top of every printed marker.  Markers’ top edges must be secured at the prescribed height and leveled horizontally.

VPS demonstration

Demonstrations of VPS software in action have been captured in videos such as this one:

During the demonstration, VPS software runs on a smartphone, and its 3-dimensional location output is shown in images that depict the device’s positions over time as a blue dot on top of a line denoting height.Visual Positioning System indoors demo

As the device moves closer to a marker, its position is depicted by the companion image:Visual Positioning System indoors demo

What is noteworthy about the video is that the VPS Dragonfly system captures and interprets location coordinates on the fly, simply by processing the images and angles of view of location markers such as the ones shown in this room.

Applications

VPS could be used by autonomous moving vehicles (robots and drones) to determine their 3-dimensional locations in real time, with good practical accuracy.

Instead of relying on technologies such as barcodes or radio signals (RFID, UWB), any camera-equipped moving vehicle could easily obtain its location coordinates and navigate around a designated area to perform its tasks.

This functionality could be useful in multiple scenarios:

  • Automated warehouses rely on autonomous moving vehicles to pick and store inventory in a large but confined environment. VPS Dragonfly can easily provide practical, accurate positioning to store and pick inventory to expedite order fulfillment.
  • Automated vehicles to monitor secured premises may leverage VPS Dragonfly to pinpoint their location as they move about, even in poor light conditions when using infrared cameras.

In brief

VPS Dragonfly can be a real asset for indoor location applications.  For instance, those environments that are very “noisy” in radio signals, particularly in the most used spectrums, such as 2.4 GHz (WiFi and BLE), can clearly benefit from an alternative that will not interfere with existing ambient signals.

Positioning systems that rely on barcodes can achieve high accuracy, but at times, that may be at the expense of flexibility. The ability to obtain 3-D locations enables a new range of possibilities for automated pick-and-place systems.

Practically, any system that can take advantage of video signal processing technology to obtain its location can easily incorporate VPS.  Once deployed, VPS systems are not susceptible to changes in the environment, such as WiFi access points going in and out of service, or RFID antennas being relocated. This is flexible, sturdy and practical.

What application do you have in mind?

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