Study on Six Degree-of-Freedom Electromagnetic Tracking System

In order to solve the problem of precision degrading caused by the different gains of three axes in six degree of freedom electromagnetic tracking system, the model of anisotropic parameters was introduced, based on magnetic dipole model. An improved arithmetic was proposed to calculate the location parameters, which was a combination of the maximal ponderance of unit pointing vector tracking arithmetic and the eigenvector arithmetic. This arithmetic solved the problem of magnifying calculation error in some angle area. The orientation transformation matrix can be calculated by received matrix, which avoids the error accumulation. These methods simplified the complexity and promoted the system stability. An new method to get the anisotropic parameters was estabished by three knowd points. The numeriacl simualtions and experiment results prove the model is valid and can improve the precision of the system.