基于圆结构光视觉传感器的标定特征点获取方法

Constructing method of calibration feature points used for circle structure light vision sensor

管道作为工业生产重要的传输手段其内表面腐蚀程度和瑕疵的精确检测对于保证安全生产具有重要意义。针对管道内表面圆结构光视觉检测,提出了一种基于共面参照物获取圆结构光视觉传感器标定特征点的新方法。该方法设计了圆结构光平面靶标,基于交比不变原理,以摄像机三维坐标系为中介,将多个局部世界坐标系下的标定特征点统一到全局世界坐标系中,得到位于圆结构光曲面上的非共线标定特征点的三维世界坐标。该方法降低了标定设备的成本,简化了结构光视觉传感器的标定过程。标定实验精度达到0.340mm,标定结果表明,该方法切实可行。

Pipe is one of the most important transmission modes in industry and the detection of the in-pipe surface is necessary to ensure the transmission safety. Circle structure light vision sensor is extensively used to measure the three-dimensional size of devices because of its char- acteristics of high precision, large information and non contact. The calibration of the circle structure light vision sensor is the most important step to realize the measurement. A novel constructing method of calibration feature points for circle structure light vision sensor was proposed based on coplanar reference object. First the calibration points were obtained based on the invariance of cross ratio in different plane position, then via the camera coordinate sys-tem, the transfromation between the different plane local coordinate system and the world co- ordinate system was realized, finally the space calibration feature points were constructed based on the world coordinate system. The proposed method greatly reduces the cost of the calibration equipment and simplifies the calibrating procedure. The calibration precision a- chieves 0. 340 mm which proves the feasibility of the method.