基于特征点位置校正的靶标位姿测量方法

针对图像式路基沉降监测系统中由于振动等因素导致靶标与相机发生偏转产生测量误差的问题,本文在设计监测系统靶面位姿测量系统的基础上提出了基于4特征点位置校正的位姿测量方法.首先介绍了图像式路基沉降监测方法的工作原理;然后根据实际情况设计了区别于传统特征点的4特征点靶面的位姿测量系统,并利用特殊特征点对靶面特征点进行位置校正;最后根据设计的4特征点靶面测量系统提出已知矩形4特征点边长的位姿求解方法.实验结果表明:本文方法比迭代法位姿解算后角度误差值更小,其位姿解算相对误差减小1.2%.当偏转角度小于2°时,本文方法位姿求解旋转角度误差小于0.09°,相对角度误差为1.003%.其时间和测量精度都能够达到监测系统要求,可以应用于监测系统中需要对相机和靶标进行实时标定的场景.

The Measurement Method of Target Pose Based on Feature Points Position Calibration

Aiming at the problem of measurement error caused by the deflection of the target and the camera in the image subgrade settlement monitoring system due to vibration, a pose measurement method based on 4 feature points position calibration was proposed. Firstly, the operational principle of the image based settlement monitoring method was introduced and the components and working model of the online surface settlement monitoring system were described. Then, different from the traditional feature points a pose measurement system with the 4 feature points target surface is designed, and using special feature point to calibrate the target surface. Finally, the method of target pose based on rectangular side length known was proposed. Experimental results show that the angle error of this method is smaller than that of the iterative method, the relative error of the pose solution is reduced by 1.2 %. When the deflection angle is less than 2°, the method solves the rotation angle error of less than 0.09°, the relative angular error is 1.003 %. The time and accuracy of the proposed method can meet the requirements of the monitoring system, it can also be applied to scenes in the monitoring system that require real-time calibration of the camera and target.