单摄像机全向立体视觉传感器的结构设计

Structure Design of Single Camera Omnidirectional Stereo Vision Sensor

传统宽视场三维测量常采用多传感器构建的测量系统实现,传感器的同步和多传感器测量坐标系的统一两大难点导致测量精度与测量速度难以兼容。为了实现更宽视场范围内目标物的实时三维测量,设计了1种由单摄像机和2个四棱锥反射镜构成的全向立体视觉传感器。2个四棱锥反射镜对称摆放,顶部相对,下四棱锥顶端安装高分辨率工业摄像机。四棱锥反射镜成像形成4对虚拟摄像机,等效于传统双目视觉传感器的1对摄像机同时采集同名特征点,从而由4对虚拟摄像机实现水平4个方向的同步测量。解决了传统双目视觉传感器体积大、视场狭小、图像采集不同步等问题,且有效保证了图像的透视投影不变性,避免了曲面镜成像产生的图像畸变,减小了后续工作难度。

Conventional wide-field three-dimensional（3D）measurement is usually implemented by measuring system consisting of multiple sensors.Difficulties,including sensor synchronization and unified measuring coordinate system of multiple sensors,lead to the incompatibility between high accuracy and high speed.An omnidirectional stereo vision sensor consisting of a single camera and two rectangular pyramid mirrors is designed to realize real-time3 D measurement of objects in wider field.The rectangular pyramid mirrors are symmetrically placed,with their top opposite to each other,and a high resolution industrial camera is set at the head of the under rectangular pyramid.The rectangular pyramid mirrors are reflecting and imaging as four pairs of virtual cameras.It is equivalent to the traditional binocular vision sensor in which the counterpart points are obtained by two cameras. Thus synchronization measurement in horizontal four direction is realized by four pairs of virtual cameras.Some disadvantages of traditional binocular vision sensor are overcame,such as big size,narrow field of view,asynchronous image collection etc.Moreover,constant perspective projection of images is ensured and distortion in images reflected by curved mirror is avoided,which makes the later work much easier.