Pedestrian positioning system(PPS)using wearable inertial sensors has wide applications towards various emerging fields such as smart healthcare,emergency rescue,soldier positioning,etc.The performance of traditional ...Pedestrian positioning system(PPS)using wearable inertial sensors has wide applications towards various emerging fields such as smart healthcare,emergency rescue,soldier positioning,etc.The performance of traditional PPS is limited by the cumulative error of inertial sensors,complex motion modes of pedestrians,and the low robustness of the multi-sensor collaboration structure.This paper presents a hybrid pedestrian positioning system using the combination of wearable inertial sensors and ultrasonic ranging(H-PPS).A robust two nodes integration structure is developed to adaptively combine the motion data acquired from the single waist-mounted and foot-mounted node,and enhanced by a novel ellipsoid constraint model.In addition,a deep-learning-based walking speed estimator is proposed by considering all the motion features provided by different nodes,which effectively reduces the cumulative error originating from inertial sensors.Finally,a comprehensive data and model dual-driven model is presented to effectively combine the motion data provided by different sensor nodes and walking speed estimator,and multi-level constraints are extracted to further improve the performance of the overall system.Experimental results indicate that the proposed H-PPS significantly improves the performance of the single PPS and outperforms existing algorithms in accuracy index under complex indoor scenarios.展开更多
针对传统农业灌渠流量测量装置成本高、测量精度低的问题,该研究设计了一种基于超声波时差法的方箱流量计。首先,设计了方箱流量计机械结构,提出错层阵列布局方法,有效增加通道数量。其次,设计了与之配套的多通道数据采集电路,通过增加...针对传统农业灌渠流量测量装置成本高、测量精度低的问题,该研究设计了一种基于超声波时差法的方箱流量计。首先,设计了方箱流量计机械结构,提出错层阵列布局方法,有效增加通道数量。其次,设计了与之配套的多通道数据采集电路,通过增加升压驱动电路和回波调理电路,对时间数字转换器(timer digital converter,TDC)测时电路进行改进,以提升测量距离和回波信号检测的准确性。利用模拟开关切换电路实现16通道共享测时电路,以降低电路成本。最后,数据处理中通过数据校正和引入53H改进算法、加权数据融合改进算法实现灌渠流速的精确测量。在静水试验中对数据采集电路的性能进行测试,同时,测试温度对测量结果的影响。在动水试验中,与电磁流量计测量结果进行了对比。结果表明,通道非线性误差最大为0.95%;通道不一致性为(0.047±0.032)ns,带来的水流速度误差最大为3.06×10^(-)4m/s;超声波换能器不一致性为(0.288±0.215)ns,带来的水流速度误差最大为2.50×10^(-3)m/s,以上误差可通过数据校正的方法予以修正。在20~40℃范围内,流速的均方差为1.70×10^(-4)m/s,温度对测量结果的影响可忽略不计。在动水试验中,方箱流量计测量相对于电磁流量计偏差为0.16%~0.93%,达到了与电磁流量计同等的测量精度。研究结果可为精确测量灌渠流量、实现高效节水灌溉提供技术支撑。展开更多
基金supported by the National Natural Science Foundation of China under(Grant No.52175531)in part by the Science and Technology Research Program of Chongqing Municipal Education Commission under Grant(Grant Nos.KJQN202000605 and KJZD-M202000602)。
文摘Pedestrian positioning system(PPS)using wearable inertial sensors has wide applications towards various emerging fields such as smart healthcare,emergency rescue,soldier positioning,etc.The performance of traditional PPS is limited by the cumulative error of inertial sensors,complex motion modes of pedestrians,and the low robustness of the multi-sensor collaboration structure.This paper presents a hybrid pedestrian positioning system using the combination of wearable inertial sensors and ultrasonic ranging(H-PPS).A robust two nodes integration structure is developed to adaptively combine the motion data acquired from the single waist-mounted and foot-mounted node,and enhanced by a novel ellipsoid constraint model.In addition,a deep-learning-based walking speed estimator is proposed by considering all the motion features provided by different nodes,which effectively reduces the cumulative error originating from inertial sensors.Finally,a comprehensive data and model dual-driven model is presented to effectively combine the motion data provided by different sensor nodes and walking speed estimator,and multi-level constraints are extracted to further improve the performance of the overall system.Experimental results indicate that the proposed H-PPS significantly improves the performance of the single PPS and outperforms existing algorithms in accuracy index under complex indoor scenarios.
文摘针对传统农业灌渠流量测量装置成本高、测量精度低的问题,该研究设计了一种基于超声波时差法的方箱流量计。首先,设计了方箱流量计机械结构,提出错层阵列布局方法,有效增加通道数量。其次,设计了与之配套的多通道数据采集电路,通过增加升压驱动电路和回波调理电路,对时间数字转换器(timer digital converter,TDC)测时电路进行改进,以提升测量距离和回波信号检测的准确性。利用模拟开关切换电路实现16通道共享测时电路,以降低电路成本。最后,数据处理中通过数据校正和引入53H改进算法、加权数据融合改进算法实现灌渠流速的精确测量。在静水试验中对数据采集电路的性能进行测试,同时,测试温度对测量结果的影响。在动水试验中,与电磁流量计测量结果进行了对比。结果表明,通道非线性误差最大为0.95%;通道不一致性为(0.047±0.032)ns,带来的水流速度误差最大为3.06×10^(-)4m/s;超声波换能器不一致性为(0.288±0.215)ns,带来的水流速度误差最大为2.50×10^(-3)m/s,以上误差可通过数据校正的方法予以修正。在20~40℃范围内,流速的均方差为1.70×10^(-4)m/s,温度对测量结果的影响可忽略不计。在动水试验中,方箱流量计测量相对于电磁流量计偏差为0.16%~0.93%,达到了与电磁流量计同等的测量精度。研究结果可为精确测量灌渠流量、实现高效节水灌溉提供技术支撑。
