Four-wheel positioning homography matrix optimization algorithm based on minimum re-projection error

A fast and accurate homography matrix method for four-wheel positioning detection was presented in the paper. Fewer sensors were required with simpler operation and faster detection. Firstly, eight feature points were extracted by using the target detection algorithm based on the fitting method. Secondly, six feature points were obtained by line fitting-based selection. Thirdly, from the selected six feature points, five points were randomly chosen to minimize the re-projection error. Finally, four points were randomly selected from these five feature points to find the homography matrix, and the other point was back to the homography matrix for verification. The experimental results show that the mean re-projection error is reduced by about 3.41%-4.57% compared with the modified RANSAC (Random sample consensus) algorithm. With the optimized algorithm, the error is reduced by about 12.81%-13.86% compared with the improved RANSAC algorithm. Compared with traditional targets, the average calibration time is reduced by about 26.95%-27.88%. The results indicated that the combination of target algorithm and optimization algorithm could ensure the accuracy and reliability of four-wheel positioning.