Dynamic approach of camera auto-calibration for vision system on autonomous vehicle

A dynamic auto-calibration approach using relevant invariant of vanishing points in the road image was presented in order to solve the on-line auto-calibration problem of extrinsic camera rotation parameters after the autonomous vehicle changes the pose of the vision sensors. Firstly the vanishing point was analyzed in real time from the road video sequence collected by the car, then the main vanishing point and vanishing line were dynamically estimated according to the central limit theorem and using the corresponding statistic, and finally the dynamic solution that corresponds to camera extrinsic parameters of the current statistical characteristics was obtained by analytically solving the vanishing point and line equations with the pinhole imaging model. The experiment shows that after adjusting the pose of the camera, this algorithm can precisely calibrate the extrinsic rotation parameters within ninety frames and the absolute error of extrinsic rotation parameters is less than 0.001 rad.