Pitch angle estimation using a Vehicle-Mounted monocular camera for range measurement

To achieve a usable range measurement feature using a Vehicle-Mounted monocular camera for ADAS (Advantage Drive Assist System), a pitch angle estimation with high accuracy is required. We propose a method for estimating pitch angle with a non-occurrence of cumulative error, and the initial pitch angle can be estimated simultaneously with only a Vehicle-Mounted monocular camera. We use the Harris-corner algorithm and the pyramid Lucas-Kanade method to detect the optical flow of feature points between adjacent frames from the monocular camera. With the result of the optical flow detection using Structure from Motion method to estimate the camera ego-motion parameters, including the rotation matrix and the translation vector, and to optimize the estimated ego-motion parameters using the Gauss-Newton method. In addition, we propose a method of estimating pitch angle relative to the road surface from the translation vector. The pitch angle and the pitch angle rate decomposed from the rotation matrix of the adjacent frames are composed using an average transfer method, to achieve the high accuracy pitch estimation. Further, the effectiveness of the proposed method is confirmed by experiment.