Loading [a11y]/accessibility-menu.js
An Improved Magnetic Tracking Method Using Rotating Uniaxial Coil With Sparse Points and Closed Form Analytic Solution | IEEE Journals & Magazine | IEEE Xplore

An Improved Magnetic Tracking Method Using Rotating Uniaxial Coil With Sparse Points and Closed Form Analytic Solution


Abstract:

A set of triaxial magnetic transmitting coils fed with low frequency sinusoidal signals can be tracked with a rotating uniaxial sensing coil. This is because the specific...Show More

Abstract:

A set of triaxial magnetic transmitting coils fed with low frequency sinusoidal signals can be tracked with a rotating uniaxial sensing coil. This is because the specific output signal of the sensing coil will reach a maximum value when the direction of its induced magnetic field points to the transmitting coils. Usually, a rotating method is used to find the maximum output direction based on the output signals from the sensing coil. This method needs a horizontal rotation phase and a vertical rotation phase to search for the maximum output and its accuracy depends on the rotation step size. In order to simplify the rotation process while maintaining the accuracy without reducing the rotation step size, an improved magnetic tracking method is proposed in this paper. It is found that when the sensing coil rotates in the horizontal plane, the specific output signals compose a sinusoidal curve. By extracting the amplitude, phase, and dc component of this sinusoidal signal, the distance and direction information between the sensing coil and transmitting coils can be estimated and no vertical rotating phase is needed. Another advantage of this method is that the tracking accuracy does not depend on the rotation step size once the sampling rate fulfills the Nyquist–Shannon sampling theorem. Therefore, we can use sparse points to reconstruct the sinusoidal signal. Experimental results will show the effectiveness of this tracking method.
Published in: IEEE Sensors Journal ( Volume: 14, Issue: 10, October 2014)
Page(s): 3585 - 3592
Date of Publication: 05 June 2014

ISSN Information:

Funding Agency:


I. Introduction

Electromagnetic tracking (EMT) technology has been widely used in many areas, such as human-machine interaction [1], vehicle guidance [2], robotic surgery [3]–[9], and image guided interventions [10], [11], among others. This method is mainly based on the accurate mapping of the magnetic field generated by magnetic sources [12]. Based on the magnetic sources, there are two types of magnetic tracking: permanent magnet based tracking [13]–[20] and the quasi-static electromagnetic coils based tracking [3], [21]–[29]. Compared with permanent magnet based tracking, the electromagnetic (EM) method has the advantages of anti-interference and a larger working space. Orthogonal coils are the mostly used tools to serve as the transmitting coils and the sensing coils in the EMT methods as shown in Fig. 1. Two different estimation methods can be used in EMT, one of which is direct estimation and the other being rotation based estimation.

Electromagnetic tracking method. A set of triaxial orthogonal transmitting coils is often served as the magnetic field source, which is sensed by a set of triaxial orthogonal sensing coils. The relative position and orientation parameters between the transmitting coils and the sensing coils can be estimated with the sensing signals.

References

References is not available for this document.