For the second part of this series, let’s discuss the fundamentals of this mysterious term ‘6dof’, and review its role in our tracking system. Let’s start with the basics…
Where does our name, Sixdof Space, come from? What’s so unique about this technology that we’ve built a company around it?
The term “DoF” refers to “degrees of freedom” – which define the position and orientation of an object in space. There are 3 positional coordinates (typically defined as X, Y and Z) and three orientation coordinates (typically Pitch, Roll and Yaw). Taken together these 6 parameters fully define the object.
The Sixdof Space patented technology leverages infrared light sources to serve as location beacons, to report the 6dof position of the moving object.
Our sensor board is not a typical 2D or 3D camera. Our optics only sees the bright spots (LED beacons) and compresses this view into a single row of data (not a 2D matrix). With two sensors perpendicular to each other, we can optically compress the 2D image of the light into two arrays, one representing the X and one representing the Y.
Imagine a 2D image of the lights, and we are summing up the rows and the columns. The resulting two 1D arrays are a fraction of the size of the full matrix and provide sufficient data into our algorithms to provide the full 6dof positioning.
The algorithm then reports to the host the updated position (the 6dof).
This method gives you accurate relative positioning, but it will not give you the absolute position of the robot or moving object in the area. We call this localization. To achieve this, we use a technique we call coded beacons. Each beacon has a unique code – a high-speed flash sequence. When the space is outfitted with the beacons, a one-time map is created, indicating where in the physical space each beacon is located. When the sensor sees the beacon, it identifies the beacon by its code, and then matches it against the map of the beacons. This allows the system to not only know the movement, but also the absolute position.
The IR beacons come in different configurations, depending on the environment where they are being installed. We have models for ceiling mount (to be used in a typical factory environment), we have more powerful beacons for outdoor use (where they have to compete with the sun), and we have small, portable beacon modules that can be installed in machinery and equipment.
Some key benefits of doing 6dof tracking with the optical method describe above are:
· Privacy – we are not a camera
· Centimeter level accuracy
· Ability to re-localize when tracking is lost due to a momentary obstruction
· 120-degree field of view
· Support supplemental data transmission over IR channel
To see 6dof tracking in play, using the Sixdof Space technology, check out this video: https://vimeo.com/682582180/99730ba080
For more information, download our one-pager or technology presentation