交变励磁三维遥测定位方法研究

New Telemetric Three-Dimensional Positioning Method of Alternating Current Excitation

为了确定口服式生理参数检测胶囊进入人体消化道后的空间位置,提出了基于微粒群算法的交变励磁定位新方法.在人的体表布置2个圆柱状励磁线圈,通入时分正弦信号,同时在胶囊内封装3个相互正交的感应线圈.由定位模型建立以胶囊位置为变量的六元高次非线性方程组,运用改进的微粒群算法对其求解,由此实现胶囊位置的遥测.实验表明:磁定位方法正确可行,模型精度高,与传统算法相比,具有收敛速度快、精度高的优良性能.该方法不需要昂贵的大型专门设备,定位系统结构简单,能实现微型化和集成化,也可应用于其他非导磁环境中的位置遥测.

In order to determine the three-dimensional （3D） position of a detecting microcapsule in the gastrointestinal tract, a novel positioning method is presented based on alternating magnetic field and particle swarm optimization （PSO） algorithm. In telemetering two cylindrical energizing coils are located on the abdomen. Both coils are excited by timesharing sinusoidal signal, and three induction coils whose axes are orthogonally mounted are sealed in the microcapsule. According to Biot-Savart law and Lenz law, a positioning model describing the relation between the induced electromotive force and the 3D position is derived. Then the position and orientation of the microcapsule are calculated via a nonlinear equation system by the improved PSO algorithm. The experiment shows that the positioning method is correct and the model has high precision. The PSO algorithm succeeds in solving high dimension problems, and its precision and performance are superior to conventional algorithms. The positioning method needs not special and expensive apparatus, and the miniaturization and integration can be easily realized.