A Novel Wireless 5-D Electromagnetic Tracking System Based on Nine-Channel Sinusoidal Signals

Electromagnetic tracking systems (EMTSs) are widely employed in medical instruments, virtual reality, game control, etc. An EMTS mainly consists of three parts:magnetic field generator connected with transmitting coils, control unit, and sensing and computing unit. In general, the transmitting coils and the induction coils of an EMTS are connected to the same control unit to determine an induced electromotive force resulted from transmitting coil. In this article, a novel EMTS is presented, whose induction coils are separated from the control unit; hence, the wireless pose tracking can be achieved. To improve the tracking speed and determine an induced electromotive force resulted from transmitting coil, the transmitting coils are simultaneously excited by nine-channel sinusoidal signals with different frequencies, instead of the switching channels in the chronological order. Thus, five-degree-of-freedom tracking of the miniature induction coil is implemented. The experimental results show that the average position and the orientation errors are less than 2.3 mm and 0.2°, respectively, which indicates that the proposed EMTS has potential prospects for both medical and industrial applications, especially for the magnetically controlled capsule robot.