基于图像处理技术检测弓网接触力的新方法

Image Processing Based Method for Measuring Contact Force in Pantograph-Catenary System

接触网和受电弓是电气化铁路供电系统中的重要组成部分,其中弓网之间的动态接触又是保证电力机车良好受流的关键条件,所以寻求良好的弓网关系是铁路供电系统设计的一个重点.考虑到目前弓网接触力大多采用接触式检测手段,对于非接触检测的研究方法较少,故提出了一种基于图像处理算法检测弓网接触力的新方法.简化受电弓弓头结构,分析了弓网接触力与弓头位移之间的关系,建立弓网接触力计算模型;并在弓网混合模拟试验台进行地面验证实验:首先,利用图像处理模块对采集到的图像进行标记点的目标跟踪与特征提取;然后,通过数据处理模块对得到的位移信息进一步分析得到弓头加速度等信息,修正得到加速度信号;最后,对经过惯性力和阻尼力修正后的接触力结果进行分析.结果表明:通过图像处理检测得到的弓头位移最大测量误差仅为1.3 mm,精度较高;同时检测得到的弓网动态接触力的最大值、平均值和标准差的最大相对误差仅为5.46%、5.15%和4.58%,测量误差较小.结果证实此方法检测弓网接触力是可行的,且检测精度满足要求.

Catenary and pantograph are important parts in the power supply system for electrified railways.The dynamic contact between the pantograph and the catenary is pivotal to ensure that the electric locomotives acquire good electricity.Therefore,good dynamic contact between the pantograph and the catenary is a key in the design of the railway power supply system.Given that the contact detection method is common for pantograph catenary contact force at present,and there are few research methods for non-contact detection,a new method based on the image processing algorithm is proposed for detecting pantograph catenary contact force.First,the structure of the pantograph head is simplified,the relationship between the pantograph dynamic contact force and the pantograph head displacement is analyzed,and a new model for calculating the contact force is developed.Next,the ground validation test is conducted on the pantograph-catenary hybrid simulation platform.In tests,the image processing module is used for target tracking and feature extraction of marked points in the collected image.Then,the displacement information is further analyzed by the data processing module to obtain the pantograph head acceleration and other information,and the acceleration signal is corrected.Finally,the contact force results corrected by inertia force and damping force are analyzed.The test results show that the maximum error of the pantograph head displacement detected by image processing is 1.3 mm,showing a high accuracy.Meanwhile,the maximum relative errors of the maximum,average and standard deviation of the dynamic pantograph-catenary contact force are only 5.46%,5.15%and 4.58%,demonstrating that the measurement error is small.Thus,this method is feasible in detecting the pantograph-catenary contact force and its detection accuracy meets the requirements.