无线内窥镜中圆柱永磁体建模与仿真

Modeling and Simulation for Permanent Column in Wireless Endoscope

圆柱永磁体的数学模型的确定是无线内窥镜在体内空间定位的关键。通常的方法是将圆柱永磁体近似为磁偶极子来进行空间磁场的建模,但其前提条件是场点半径要远大于圆柱永磁体的半径,故在近区该模型并不适用。针对这个问题,运用一种基于等效磁荷法的模型分析该区域空间磁场,该模型适用于圆柱永磁体外任何空间,且方程简单。最后,在MATLAB6.5环境下对该模型进行仿真,并运用ANSYS软件对圆柱永磁体磁场进行验证,仿真结果表明其可行性和优越性。

The mathematical model for permanent column is a key problem for the location of the wireless endoscope. The permanent column is usually regarded as magnetic-dipole to calculate space magnetic field, but it has a precondition that field radius is far-forth bigger than permanent column radius, and it can not reflect vicinity field. To solve this question, an equivalent magnetic charge method was proposed for calculating magnetic field, which does not need precondition and can reflect permanent column magnetic field correctly, and it＇s simple. Finally, the model was stimulated in MATLAB6.5 and the results indicate that the model is feasible and superiority.