Real-time satellite orbit and clock corrections obtained from the broadcast ephemerides can be improved using IGS real-time service (RTS) products. Recent research showed that applying such corrections for broadcast e...Real-time satellite orbit and clock corrections obtained from the broadcast ephemerides can be improved using IGS real-time service (RTS) products. Recent research showed that applying such corrections for broadcast ephemerides can significantly improve the RMS of the estimated coordinates. However, unintentional streaming interruption may happen for many reasons such as software or hardware failure. Streaming interruption, if happened, will cause sudden degradation of the obtained solution if only the broadcast ephemerides are used. A better solution can be obtained in real-time if the predicted part of the ultra-rapid products is used. In this paper, Harmonic analysis technique is used to predict the IGS RTS corrections using historical broadcasted data. It is shown that using the predicted clock corrections improves the RMS of the estimated coordinates by about 72%, 58%, and 72% in latitude, longitude, and height directions, respectively and reduces the 2D and 3D errors by about 80% compared with the predicted part of the IGS ultra-rapid clock corrections.展开更多
针对室外大范围场景移动机器人建图中,激光雷达里程计位姿计算不准确导致SLAM(simultaneous localization and mapping)算法精度下降的问题,提出一种基于多传感信息融合的SLAM语义词袋优化算法MSW-SLAM(multi-sensor information fusion...针对室外大范围场景移动机器人建图中,激光雷达里程计位姿计算不准确导致SLAM(simultaneous localization and mapping)算法精度下降的问题,提出一种基于多传感信息融合的SLAM语义词袋优化算法MSW-SLAM(multi-sensor information fusion SLAM based on semantic word bags)。采用视觉惯性系统引入激光雷达原始观测数据,并通过滑动窗口实现了IMU(inertia measurement unit)量测、视觉特征和激光点云特征的多源数据联合非线性优化;最后算法利用视觉与激光雷达的语义词袋互补特性进行闭环优化,进一步提升了多传感器融合SLAM系统的全局定位和建图精度。实验结果显示,相比于传统的紧耦合双目视觉惯性里程计和激光雷达里程计定位,MSW-SLAM算法能够有效探测轨迹中的闭环信息,并实现高精度的全局位姿图优化,闭环检测后的点云地图具有良好的分辨率和全局一致性。展开更多
分析当前铁路列车巡检人员现状及发展趋势,设计了一种基于RFID技术的铁路列车检修人员定位装置。系统以STM32F103C8T6为控制核心,利用型号为nRF24LE1的RFID无限射频芯片进行巡检人员电子标签信息的收发,主控模块根据TOA(Time of Arrivi...分析当前铁路列车巡检人员现状及发展趋势,设计了一种基于RFID技术的铁路列车检修人员定位装置。系统以STM32F103C8T6为控制核心,利用型号为nRF24LE1的RFID无限射频芯片进行巡检人员电子标签信息的收发,主控模块根据TOA(Time of Arriving)定位算法计算出标签的位置信息,利用均值滤波算法进行位置信息的校正处理,采用无线通信GPRS模块将巡检人员的位置信息实时传送到调度中心。该系统可实现完整的巡检人员智能定位,有效提升铁路列车运维效率。展开更多
文摘Real-time satellite orbit and clock corrections obtained from the broadcast ephemerides can be improved using IGS real-time service (RTS) products. Recent research showed that applying such corrections for broadcast ephemerides can significantly improve the RMS of the estimated coordinates. However, unintentional streaming interruption may happen for many reasons such as software or hardware failure. Streaming interruption, if happened, will cause sudden degradation of the obtained solution if only the broadcast ephemerides are used. A better solution can be obtained in real-time if the predicted part of the ultra-rapid products is used. In this paper, Harmonic analysis technique is used to predict the IGS RTS corrections using historical broadcasted data. It is shown that using the predicted clock corrections improves the RMS of the estimated coordinates by about 72%, 58%, and 72% in latitude, longitude, and height directions, respectively and reduces the 2D and 3D errors by about 80% compared with the predicted part of the IGS ultra-rapid clock corrections.
文摘针对室外大范围场景移动机器人建图中,激光雷达里程计位姿计算不准确导致SLAM(simultaneous localization and mapping)算法精度下降的问题,提出一种基于多传感信息融合的SLAM语义词袋优化算法MSW-SLAM(multi-sensor information fusion SLAM based on semantic word bags)。采用视觉惯性系统引入激光雷达原始观测数据,并通过滑动窗口实现了IMU(inertia measurement unit)量测、视觉特征和激光点云特征的多源数据联合非线性优化;最后算法利用视觉与激光雷达的语义词袋互补特性进行闭环优化,进一步提升了多传感器融合SLAM系统的全局定位和建图精度。实验结果显示,相比于传统的紧耦合双目视觉惯性里程计和激光雷达里程计定位,MSW-SLAM算法能够有效探测轨迹中的闭环信息,并实现高精度的全局位姿图优化,闭环检测后的点云地图具有良好的分辨率和全局一致性。
文摘分析当前铁路列车巡检人员现状及发展趋势,设计了一种基于RFID技术的铁路列车检修人员定位装置。系统以STM32F103C8T6为控制核心,利用型号为nRF24LE1的RFID无限射频芯片进行巡检人员电子标签信息的收发,主控模块根据TOA(Time of Arriving)定位算法计算出标签的位置信息,利用均值滤波算法进行位置信息的校正处理,采用无线通信GPRS模块将巡检人员的位置信息实时传送到调度中心。该系统可实现完整的巡检人员智能定位,有效提升铁路列车运维效率。
