Abstract: In the field of computer vision,multiple camera sensors need to be used to obtain three-dimensional information of the object so as to achieve a series of measurements such as detection,positioning and size estimation of large target objects.In actual applications,in complex environments,there will be a problem of non-overlapping field of view between the cameras,which prevents effective visual measurement.Therefore,in order to solve the calibration problem of multiple cameras,a multi-camera calibration method with constraints is proposed,without changing the mechanical structure.First,install the cameras in a fixed position,and ensure that there is no vibration between the cameras,by establishing a multi-camera optimization mathematical model and the cameras simultaneously collecting the pose parameter relationships of multiple sets of cameras corresponding to the calibration board,and using the SVRG optimization algorithm to achieve Optimize the pose parameters between the camera coordinate systems,and then obtain the pose matrix between multiple cameras.Finally,the coordinate system transformation matrix between the cameras is used to obtain the relative pose parameters between the corresponding targets as the evaluation accuracy index.And combined with the actual large-scale shield machine to carry out simulation experiment and actual test.The results show that this method has strong anti-interference,stable optimization effect,and can achieve millimeter-level accuracy in practical applications.

Key words: Vision measurement, Camera calibration, Non-overlapping field of view, Shield machine, Pose estimation