光学靶标遮挡条件下掘进机定位解算方法

A positioning solution method for roadheader under optical target occlusion conditions

针对目前常用的基于惯导+视觉测量+光学靶标的掘进机组合式导航定位存在的光学靶标被遮挡情况下掘进机定位中断问题,提出了一种光学靶标遮挡条件下掘进机定位解算方法。首先,采集4个呈矩形分布的靶标点组成的光学靶标在无遮挡情况下的图像,得到靶标点在相机内成像光斑的像素坐标并构造成矩形,再按照一定比例扩大构造辅助矩形区域框。其次,采集部分靶标点被遮挡情况下的图像,得到无遮挡靶标点在相机内成像光斑的像素坐标,根据靶标点的成像光斑与辅助矩形区域框顶点的欧氏距离,确定无遮挡靶标点与成像光斑的对应关系,进而确定被遮挡的靶标点。然后,利用已知的靶标几何尺寸和惯导提供的靶标姿态信息,建立投影后的靶标点与成像光斑的对应关系,进而求解出被遮挡靶标点对应的光斑像素坐标。最后,利用N点位姿透视求解(PNP)算法求得光学靶标中心位置的空间坐标,实现掘进机定位解算。试验结果表明,光学靶标被遮挡情况下,通过推算被遮挡靶标点对应的光斑像素坐标,可以解决掘进机定位中断问题,保证了掘进机定位的实时性,且定位误差满足掘进机实际定位需求。

In order to solve the problem of interruption in the positioning of roadheader in the case that the optical target is blocked under the current commonly used integrated navigation positioning of roadheader based on"inertial navigation+visual measurement+optical target",a positioning solution method for roadheader under optical target occlusion occlusion is proposed.Firstly,the method collects images of an optical target composed of four rectangular distributed target points in unblocked conditions,obtains the pixel coordinates of the imaging spot of the target points in the camera,and constructs a rectangle.Then,the method expands and constructs an auxiliary rectangular area box according to a certain proportion.Secondly,the method collects images of partially blocked target points,obtains the pixel coordinates of the imaging spot of the unblocked target points in the camera.The method determines the corresponding relationship between the unblocked target points and the imaging spot based on the Euclidean distance between the imaging spot of the target points and the vertex of the auxiliary rectangular area box,thereby determining the blocked target points.Thirdly,using the known geometric dimensions of the target and the target attitude information provided by inertial navigation,the method establishes the corresponding relationship between the projected target point and the imaging spot,and then solves for the pixel coordinates of the spot corresponding to the blocked target point.Finally,the spatial coordinates of the center position of the optical target are obtained using the perspective-N-point(PNP)algorithm to achieve the positioning solution of the roadheader.The experimental results show that when the optical target is blocked,by calculating the pixel coordinates of the light spot corresponding to the blocked target point,the problem of interruption in the positioning of the roadheader can be solved.It ensures the real-time positioning of the roadheader,and the positioning error meets the actual positioning requirements of the roadheader.