复杂环境下GNSS/INS紧组合垂直振动监测精度评估

Accuracy evaluation of GNSS/INS tight combination vertical vibration monitoring in complex environment

桥梁主体结构垂直方向的动态位移能直接反映其在车辆等荷载作用下的状态变化,也是桥梁结构健康监测的重要内容之一。全球卫星导航系统(GNSS)已在桥梁动态位移监测中得到推广应用,但其信号容易受到桥梁缆索、桥塔、过往车辆等障碍物的遮挡和干扰,影响监测精度。将惯性导航系统(INS)与GNSS组合进行监测,一定程度上增强了抗干扰能力,但也会因为GNSS信号质量的下降而影响对惯性传感器累积误差的校正。为正确评估复杂环境下GNSS/INS紧组合垂直振动监测精度,利用振动台设置幅值已知的振动,并在开阔环境、各种模拟遮挡环境以及多径环境中进行测试。结果表明,在开阔环境中,紧组合解算模式相比于GNSS动态单历元解算精度略有提升;而在复杂遮挡环境下,随着GNSS可视卫星数减少,紧组合解算对定位结果精度的提升效果可以达到15%;在多径环境下,INS增加了集成系统的抗干扰能力。

The vertical dynamic displacement of the main structure of the bridge can directly reflect its state change under the action of vehicles and other loads.It is also one of the important contents of bridge structure health monitoring.Global Navigation Satellite System(GNSS)has been widely used in bridge dynamic displacement monitoring,but its signal is easily blocked and interfered by obstacles such as bridge cables,towers and passing vehicles,which affects the monitoring accuracy.The combination of Inertial Navigation System(INS)and GNSS for monitoring enhances the anti-interference ability to a certain extent,but it will also affect the correction of inertial sensor cumulative error due to the decline of GNSS signal quality.In order to correctly evaluate the monitoring accuracy of GNSS/INS compact combination vertical vibration in complex environment,the vibration with known amplitude is set by shaking table and tested in open environment,various simulated shielding environments and multipath environment.The results show that in the open environment,the precision of compact combination solution mode is slightly higher than that of GNSS dynamic single epoch solution;In the complex occlusion environment,with the reduction of the number of GNSS visual satellites,the improvement effect of tight combination solution on the accuracy of positioning results can reach 15%;In multipath environment,INS increases the anti-interference ability of the integrated system.