MEMS sensors could provide more accurate motion capture

A new microelectromechanical (MEMS) sensor system is claimed to be able to achieve full-body motion capture and gesture control at a lower cost and greater accuracy than current optical and video offerings.

Movea hopes to market its MotionPod sensors to sports engineers and the film industry initially, before turning to the games industry and makers of consumer devices.

Traditional full-body motion capture typically uses dots or balls attached to a suit worn by actors with cameras capturing their movement. This efficient but costly system requires a fully equipped motion-capture room, experienced users and sophisticated programs to convert this into usable information for controlling computer avatars.  

Meanwhile, video-based devices, namely Microsoft’s Kinect, have allowed full-body motion capture without the need for peripheral sensors. Yanis Caritu, co-founder of Movea, admitted that Kinect provides ease-of-use, but said there are limitations.

‘The problem is, you are confined into a very limited space because of the field of view of the camera; you have to stay inside a band. Also, it has difficulty with several players,’ he told The Engineer.

MotionPod incorporates a three-axis accelerometer, a three-axis gyroscope and a three-axis magnetometer with integrated software and a 2.4GHz wireless transmitter with range of up to 30m to a USB receiver.

Up to five MotionPods mounted on a bracelet or strap are placed on the body at strategic points to form a ‘body area network’, which enables detailed motion to be captured in real time with dynamic accuracy of just one degree — making it attractive to sports scientists, Caritu claimed.

The MotionPod system may also allow gesture recognition by comparing real-time motion data against a library of moves, such as those used in yoga or martial arts.

Click here for an appraisal of Kinect by a team of sports engineers from Sheffield Hallam University.