地下工程测量中陀螺定向过程简化研究

Simplification Study of Gyro Orientation Process in Underground Engineering Survey

陀螺定向是地下工程测量中的重要组成部分。针对自动陀螺经纬仪在受到埋深、金属矿物或磁场影响粗略指北困难而导致的无法定向以及传统陀螺定向方法比较费时、作业效率低的问题,提出了粗定向和子午线收敛角计算的简化方案。该方法通过对准照准点读出方向值,仪器照准部根据陀螺北方向回转坐标反算出的陀螺方位角所对准的方向即为近似北方向。在陀螺定向过程中,只要满足定向边与已知边的已知点相对位置在Δx≤4 000 m,Δy≤60 m范围内,在计算未知边方位角时可以不添加子午线收敛角改正数,否则,有必要添加子午线收敛角改正数;当Δy≥200 m时,必须添加子午线收敛角改正数,否则,会影响定向精度。通过对地铁陀螺定向工程的试验测试,得到了简化方案在地下陀螺定向应用中的实测数据。研究表明:所提出的简化方案解决了自动陀螺经纬仪在受埋深或磁场影响无法粗略指北的问题,缩短了传统定向方法 30 min的定向时间、节省了15%电量、提高了作业效率,使得1 d内能够完成一次完整的陀螺定向工作,陀螺定向精度得到了保证。

Gyro orientation is an important component in underground engineering survey.Aiming at the problem that the automatic gyro theodolite is difficult to point north roughly because of the influence of burial depth,metal minerals or magnetic field,which makes it impossible to orient,meanwhile,the traditional gyro orientation method is time-consuming and inefficient,this paper presents a simplified scheme for calculating the rough orientation and meridian convergence angle.The direction value according to the reference point can be obtained.The azimuth angle of the gyroscope calculated by the illumination unit according to the gyroscope’s northward rotation coordinates is approximately northward.In the course of gyroscopic orientation,as long as the relative position between the orientation edge and the known point of the known edge is within the range of Δx ≤ 4 000 m,Δy ≤ 60 m,the correction of meridian convergence angle can not be added in calculating the azimuth angle of the unknown edge;otherwise,it is better to add the correction of meridian convergence angle;when Δy ≥ 200 m,the correction of meridian convergence angle must be added,or it will affect the orientation. Through test of the metro gyro orientation projects,measured data of the simplified scheme in the application of underground gyro orientation are obtained.The study results show that the simplified scheme proposed in this paper solves the problem that the automatic gyro theodolite can not point north roughly under the influence of buried depth or magnetic field. It reduces the orientation time of traditional orientation method for 30 minutes,saves 15% electricity,improves the operation efficiency,enables a gyro orientation task to be completed in one day,besides that,the accuracy of gyro orientation is guaranteed.