| 英文摘要 | In the fields of robotic applications, visual guidance is a key function and an important way of controlling the robot's movements. As for the table tennis robot,the vision system is a significant means of robot's self-perception and contacting with environment, which is also be used to capture the attractive target. In this thesis, based on the robotic table tennis system, the parameters estimation of the moving target are further investigated with the monocular vision system, mainly referring to pose measurement for humanoid robot, feature extraction of racket's movements in the striking process, rotational velocity prediction of the flying ball, the development of smart cameras used in the vision system and so on. The main contributions of the thesis include the following issues: Firstly, a novel adaptive threshold segmentation algorithm in HSV color space is proposed, based on which, the target image could be segmented stably. The cause of the image's fuzzy edge is analyzed. After that, a statistics-based edge detection algorithm with sub-pixel accuracy is presented to achieve a stable and reliable edge extraction. The accuracy of edge extraction can reach to a sub-pixel level. The body posture is estimated quickly and stably by combining the initial PnP value with OI optimization, and the real-time performance of the system and the accuracy are achieved as well by using the method. Secondly, a target segmentation algorithm with multi-constraints and wide-threshold is presented, eliminating the disturbing factors such as high reflection, low light and so on, and thus the robustness and the accuracy of the target segmentation are guaranteed. Additionally, a linear 1-D LDO edge detector is proposed to stably extract the effective edge of the characteristic lines in real time, and achieve the skeleton of thinning. Meanwhile, Hough transform algorithm is optimized and combined with RANSAC algorithm and least squares method, and in this way the accuracy and robustness of the feature lines extraction are improved. According to the facts of racket's striking movement, the feature trajectory of the racket in the striking process is extracted. Thirdly, the cause of the ball's rotation is discussed, and the rotation is divided into six categories according to the main rotational features. The crucial factors that influence the rotating mode and rotating speed are investigated, which provide the theoretical basis for the estimation of spinning ball's paramete... |
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