基于单PSD的目标空间位姿测量方法

Method of Object Pose Measurement Based on Single PSD

为了克服图像传感器在位姿测量中存在响应速度与精度相互制约以及相应图像处理算法复杂的缺陷,提出一种基于单个位置敏感探测器的目标空间位姿测量方法.首先建立以位置敏感探测器光敏面中心为原点的传感器坐标系并在该坐标系下定义空间姿态角,然后将合作目标上8个循环交替点亮的红外LED光源作为探测对象,特征发光点经过会聚镜头成像于探测器光敏面上,经信号处理得到各点二维像坐标,并结合光源相对位置关系最终解算得到目标在传感器坐标系下的空间位置和姿态.在对系统稳定性进行验证后完成了位置平移与角度旋转的测量实验.实验结果表明:提出的方法在视场角为16.3°的范围内探测距离可达10m,沿深度方向的位置测量绝对误差最大为36.2mm,其他方向位置测量平均绝对误差最大为7.1mm,角度测量绝对误差优于2°.该方法解算过程简单、实时性强,测量更新频率为100Hz,可以满足位姿检测的高速要求.

A pose measurement method based on single position sensitive detector was proposed in order to overcome the limitation of image sensor response and precision and the defect of corresponding image processing algorithm.First,a coordinate system was established while the origin was based on detector photosensitive surface center and space attitude angle was defined in this coordinate system.Then eight infrared LED light sources of plane object glowed in circle were defined as detecting target and they were imaged on the active area of the positive sensitive detector via optic system.After the electricity digital signal had been processed by the program,using two-dimensional image coordinate of feature points and specific relative position relation of light sources,the position and attitude information of object in sensor coordinate system would be gained finally.Before the measurement experiment,the stability of the system was verified.Experimental results show that measurement distance of this method is 10 m in the depth direction within the detectable field angle of 16.3°while the maximum absolute error is 36.2 mm.The maximum position measurement mean absolute deviation in other direction is 7.1 mm and angle measurement error is higher than 2°.This method is simple while real-time frequency of measurement could achieve 100 Hz and it could meet the real-time requirements in pose measurements commendably.