Together with Rokoko and Bit Blueprint I developed a motion capture system based on inertial motion sensors. It needed to be cheap and simple to setup and have support for actors standing in front of each other. Rokoko had been using tradition computer vision based MoCap setups for their Animation Childrens theater but it was too complicated and expensive, they had also been using a setup with the Microsoft kinect for a period but that was too flaky and didn't have the level of control and detail they were after. We started out with a simple prototype using arduinos and a raspberry pi as a controller, since then some parts have been replaced with more beefy hardware or custom components.
Read more on Rokoko's website http://rokoko.co/animotion/
The system is open source and available on github: https://github.com/jchillerup/rokoko