六自由度电磁跟踪系统定位模型与近场校正

Position Model of Six-DOF Electromagnetic Tracker and Near-Field Calibration Technique

为了研究电磁跟踪系统理想磁偶极子定位模型近距离定位精度,采用基于消息传递模式网络并行系统与区域分割技术实现了并行时域有限差分(FDTD)算法.以高斯脉冲为激励源,结合快速傅里叶变换,解决了FDTD难以模拟电磁跟踪系统低频正弦激励源的问题.引入勒让德多项式,建立了系统近距离工作的定位模型与校正方法.研究了系统定位距离对于理想磁偶极子定位模型精度的影响及参数定位计算的误差规律,验证了勒让德多项式近场校正模型可明显提高系统近距离工作时参数定位精度的结论.

To study the accuracy of magnetic-dipole position model,the parallel-finite difference time domain（parallel-FDTD） arithmetic is presented on a distributed network.The message passing module and space decomposition technique are applied.In FDTD application,simulation of low frequency exciting source is very difficult.The fast Fourier transform arithmetic is introduced to analyze the magnetic characteristic of some special frequency by using Gaussian pulse exciting source.The near-field position model and the calibration arithmetic are set up based on the Lagendre polynomial.The effects of position distance on magnetic-dipole position model and parameters position error rule are analyzed.Numerical results validates that the parameters accuracy could be improved by the Lagendre polynomial near-field calibration model.