管道机器人无线电磁自适应定位技术

Adaptive localization method based on wireless magnet sensors for pipeline robots

针对金属管道机器人跟踪定位问题,提出了一种改进的自适应无线电磁定位方法,在未知管道几何尺寸和周围环境电磁参数的情况下实现了管道内机器人的三维定位。首先,通过磁偶极子模型分析了管道外极低频电磁场分布规律。其次,建立了六传感器接收天线的自适应定位模型,设计了电磁发射和接收电路,基于该模型推导出了含有6个未知数的非线性方程组,并分别采用3种算法对其进行了仿真分析。最后,分别对不同壁厚及不同埋藏深度管道进行了试验研究。试验结果表明,在管道壁厚为5.74mm,埋藏深度为0.8～2m的情况下,总位置误差的平均值小于18.7cm,即比原模型减少了3.4cm,满足机器人实际工作中的定位需要。

For tracking and locating robots in the pipeline inspection accurately,a wireless adaptive location model was presented to realize the 3D position of robots without the geometrical sizes of pipelines and electromagnetic parameters of ambient medium.Firstly,extremely low frequency electromagnetic fields of pipelines were described by a magnetic dipole model.Then,an adaptive antenna positioning model based on six sensors was proposed and electromagnetic transmitter and receiver circuits were designed.Based on the model,a linear equation containing six unknown numbers was derived and three kinds of algorithms were used to analyze and simulate the equation. Finally,engineering experiments were performed on the pipes with different thicknesses and burial depths.The experiment on a pipe wall thickness of 5.74 mm and burried deep from 0.8 to 0.2 m shows that the average position error is 18.7 cm,which has been decreased by 3.4 cm compared with that of the original model.The results can satisfy the requirements of systems for non-contact,real time and adaptive location.