Wireless Magnetic Motion Capture System for Multi-Marker Detection

A wireless multi-motion capture system using five LC resonant magnetic markers has been developed and is demonstrated. Each marker has an individual resonant frequency, 157, 201, 273, 323, and 440 kHz, respectively. A new measuring technique is applied in order to reduce the acquisition time. In this new technique the markers are excited by a superposed wave corresponding to the all resonant frequencies, while the voltage signals induced through pick-up coils are separated in a frequency spectrum by FFT analysis. Regardless of the number of markers, the voltage amplitude for each resonant frequency can be easily obtained simultaneously and thus the proposed system can detect multiple markers. The positional accuracy for five markers is less than 2 mm within 100 mm of the pick-up coil array