摘要
胶囊机器人因其无创、无痛等特点在胃肠道疾病诊疗中展现出广阔的应用前景,基于永磁场的定位技术凭借其高精度与适应性,在胶囊的体内定位应用中备受关注。然而,复杂手术环境中普遍存在的铁磁物质及外来磁源,会引发硬铁、软铁效应,严重影响定位精度。为此,提出了一种融合Huber加权算法与动态初值策略的磁定位方法。首先,通过Huber核函数对可能受干扰的传感器测量值进行差异化处理,削减异常测量数据的权重;其次,通过动态初值策略降低算法对初值的敏感度。这些改进措施使算法在硬铁、软铁及其复合干扰等多种场景下,能够有效抑制异常测量导致的定位误差。实验结果表明,该方法在不同强度和类型干扰下均能获得稳定且高精度的定位结果,优化后定位误差均可控制在2 mm以内。与标准Levenberg-Marquardt(LM)算法相比,本方法的定位精度最高提升约56.69%,为复杂磁场环境下实现高精度且具有强鲁棒性的磁定位提供了一种可行方案。
Capsule robots have emerged as a promising technology for the diagnosis and treatment of gastrointestinal diseases,owing to their noninvasive nature and painless operation.Permanent magnet-based localization technology has attracted considerable attention due to its high accuracy and adaptability for in vivo applications of capsules.However,the presence of ferromagnetic materials and external magnetic sources in complex surgical environments often induces hard-iron and soft-iron effects,leading to significant degradation in localization accuracy.To address these challenges,a magnetic localization method that integrates a Huber weighted algorithm with a dynamic initialization strategy was proposed.Firstly,the Huber kernel function was employed to differentially process potentially disturbed sensor measurements,reducing the weight of outlier data.Then,a dynamic initialization mechanism was introduced to reduce the algorithm's dependence on initial parameter estimates.These enhancements enable the algorithm to effectively suppress localization errors caused by abnormal measurements in various interference scenarios,including hard-iron,soft-iron and their combined disturbances.Experimental results demonstrate that the proposed approach achieves stable and high-precision localization under diverse interference conditions,including different intensities and types,with the optimized positioning error consistently remaining below 2 mm.Compared with the conventional Levenberg-Marquardt(LM)algorithm,the proposed method improves localization accuracy by up to about 56.69%.This work provides an effective solution for achieving high-accuracy and robust magnetic localization in complex electromagnetic environments.
作者
林宇飞
苏诗荐
戴厚德
Lin Yufei;Su Shijian;Dai Houde(College of Mechanical and Electrical Engineering,Fujian Agriculture and Forestry University,Fuzhou 350002,China;Quanzhou Institute of Equipment Manufacturing,Haixi Institutes,Chinese Academy of Sciences,Quanzhou 362216,China;Department of Electronic Engineering,Chinese University of Hong Kong,Hong Kong 999077,China)
出处
《微纳电子技术》
2025年第6期83-92,共10页
Micronanoelectronic Technology
基金
福建省卫健委科技计划项目(2022ZQNZD001)
福建省科技计划项目(2023Y9136)
福建省科技重大专项(2024YZ036017)。
关键词
永磁定位
Huber核函数
胶囊机器人
磁传感器阵列
抗干扰
permanent magnetic localization
Huber kernel function
capsule robot
magnetic sensor array
anti-interference
