基于UWB的PDOA与TOF煤矿井下联合定位方法

A joint positioning method of PDOA and TOF in coal mines based on UWB

煤矿井下人员和车辆精确定位是煤矿安全高效生产的重要保障。目前矿井人员和车辆精确定位主要采用超宽带(UWB)无线通信技术,其中仅采用飞行时间(TOF)的定位方法需2个定位分站或天线联合测距和定向,存在天线间距大、不便于安装维护、定位误差大等问题。针对上述问题,提出了应用于煤矿巷道一维定位场景的基于UWB的到达相位差(PDOA)与TOF煤矿井下联合定位方法。该方法通过TOF测量定位卡与定位分站之间的距离,通过PDOA判断定位卡的方位,再根据测得的定位卡与定位分站之间的距离和方位,对定位卡进行定位。该方法根据从定位卡发送的无线电信号到达定位分站的2根天线的相位差判断定位卡的到达角度(AOA),不需要很大的天线间距即可确定定位卡的方位,缩短了定位分站的2根天线之间的距离,可将2根天线一体化,便于安装维护,提高了定位精度。煤矿井下测试结果表明,该方法定位精度在15 cm以内;在200 m测试距离范围内,定位精度不受距离远近影响;TOF测距数值稳定在相对其均值±10 cm的范围内,具有很好的稳定性。

The precise positioning of personnel and vehicles in coal mines is an important guarantee for safe and efficient production in coal mines.Currently,ultra-wideband(UWB)wireless communication technology is mainly used for the precise positioning of personnel and vehicles in coal mines.The positioning method that only uses the time of flight(TOF)requires two positioning substations or antennas for joint ranging and direction.It has problems such as large antenna spacing,inconvenience in installation and maintenance,and large positioning errors.In order to solve the above problems,a joint positioning method based on UWB phase difference of arrival(PDOA)and TOF is proposed for one-dimensional positioning scenarios in coal mines.This method measures the distance between the positioning card and the positioning substation through TOF,and judges the direction of the positioning card through PDOA.The method locates the positioning card based on the measured distance and direction between the positioning card and the positioning substation.This method determines the angle of arrival(AOA)of the positioning card based on the phase difference between the radio signals transmitted from the positioning card and the two antennas of the positioning substation.It does not require a large antenna spacing to determine the direction of the positioning card.It shortens the distance between the two antennas of the positioning substation.It integrates the two antennas to facilitate installation and maintenance,improving positioning precision.The underground testing results of coal mines show that the positioning precision of this method is within 15 cm.Within the test distance range of 200 m,the positioning precision is not affected by the distance.The TOF ranging value is stable within a range of±10 cm relative to its mean value,with good stability.