摘要
针对煤矿井下大量工作的在线设备不具备定位功能、已安装无线定位的设备易受电磁干扰导致定位精度低等问题,结合电缆故障测距的时域反射法和无线单边双向测距飞行时间法,提出了一种基于RS485数据帧计时的总线设备间距离测量方法,即以通信电缆为载体,利用通信数据在一对主从机之间往返的飞行时间来测量主从机之间的距离,总线沿线设备通过监听数据测量自身与从机之间的距离,从而实现总线上所有设备之间距离测量,并可根据2次不同参考从机的测量结果计算出设备一维分布。从计时时钟频率、主从机时钟偏差、电路时延、电磁波传播速度4个方面分析了影响距离测量精度的因素,并提出了相应措施以提高测量精度。采用1台矿用本安型显示屏为主机、8台矿用传感器为从机建立试验平台,采用该方法测量总线设备间距离,结果表明该方法无需改变硬件,只更新软件即可测量出RS485总线上所有设备之间的距离,并可建立以主机为原点的一维分布;在电缆长度5 km范围内距离测量误差不超过±1.5 m,且测量结果不受传输损耗、电磁干扰影响。
There are a large number of online equipment working in underground coal mines that do not have positioning function and the equipment installed with wireless positioning are susceptible to electromagnetic interference,resulting in low positioning accuracy.In order to solve the above problems,a distance measurement method between bus equipment based on RS485 data frame timing is proposed by combining the time domain reflectometry method of cable fault location and wireless single-sided-two-way-ranging time of flight method.The method uses the communication cable as a carrier to measure the distance between master and slave computers by using the flight time of communication data between a pair of master and slave computers.And the equipment along the bus measure the distance between themselves and slave computers by monitoring the data so as to realize the distance measurement between all equipment on the bus.Moreover,the one-dimensional distribution of equipment can be calculated based on the measurement results of 2 different reference slave computers.The factors affecting the distance measurement accuracy are analyzed from four aspects,clock frequency,master-slave computer clock deviation,circuit time delay and electromagnetic wave propagation speed.And the corresponding measures are proposed to improve the measurement accuracy.The method uses one mine intrinsically safe display as master computer and eight mine sensors as slave computers to establish the test platform so as to measure the distance between the bus equipment.The results show that this method does not need to change the hardware and only updates the software to measure the distance between all equipment on the RS485 bus,and a one-dimensional distribution with the master computer as the origin can be established.The distance measurement error within 5 km of the cable length does not exceed±1.5 m,and the measurement result is not affected by transmission loss and electromagnetic interference.
作者
柏思忠
BAI Sizhong(CCTEG Chongqing Research Institute,Chongqing 400039,China;State Key Laboratory of the Gas Disaster Detecting,Preventing and Emergency Controlling,Chongqing 400039,China)
出处
《工矿自动化》
北大核心
2021年第7期92-97,114,共7页
Journal Of Mine Automation
基金
重庆市技术创新与应用发展重点项目(cstc2019jscx-mbdxX0007)
中煤科工集团重庆研究院有限公司重点项目(2019ZDXM01,CQ2011)。
关键词
智能化煤矿
井下设备定位
设备间距离测量
RS485数据帧计时
电缆故障测距
时域反射法
单边双向测距
飞行时间法
intelligent coal mine
underground equipment positioning
distance measurement between equipment
RS485 data frame timing
cable fault location
time domain reflectometry method
single-sided-two-way-ranging
time of flight method
