High-precision Mobile Robot Localization Based On Artificial Landmakrs

The operation stability and localization accuracy are the key preconditions for promoting industrialization of mobile robot.With the help of simultaneous localization and mapping(SLAM),the robot has good positioning and navigation capabilities,thus this technology has received extensive attention from researchers at home and abroad.In recent years,visual SLAM technology often adopts features in the natural environment or joins artificial landmarks.When the texture information of the natural environment is weak,SLAM algorithm will be unstable or even invalid.Bringing in artificial landmarks can improve the accuracy and stability of the SLAM algorithm.The research of this paper is based on artificial landmarks and focusing on mapping construction and localization precision.First,this paper introduces the basic principles of mobile robots,mobile robot SLAM positioning and map construction,as well as artificial landmarks and camera pose estimation theory.Secondly,establishing a mathematical model of the artificial landmark system and camera sensors.Observing and identifying any preset artificial landmarks in the environment through the camera to get the relative pose between the camera and the artificial landmark.According to a plurality of artificial landmarks appearing in the video sequence frame taken by the camera,the pose transformation relationship between the landmarks is established,and the environment map is constructed.Then,constructing the optimization objective function based on re-projection error and operating backend optimization based on artificial landmarks.By optimizing the pose transformation between landmarks and the relative pose of the camera initial value,searching the best initial value to solve the problem that the objective function cannot converge or get the wrong optimization value during optimization.The loop closure detection as well as the removal mechanism for abnormal pose estimation is added to improve the stability and accuracy of the artificial landmark map construction.Finally,the experimental analysis of the construction ability and positioning accuracy of artificial landmark maps.The ability of mapping construction with artificial landmarks isverified in different scale scenarios.The accuracy is verified according to the distribution of artificial landmarks.Compared with classical SLAM algorithms(ORB_SLAM and LSD_SLAM),the camera computational trajectories and the real ones are analyzed,which proves that artificial landmarks have a higher precision of positioning than the natural feature points.According to the above artificial landmark map and combining the adaptive Monte Carlo algorithm,the global positioning of the mobile robot is realized.Compared with the given initial position of the robot,the scheme is more precise and faster,and is more adaptable in industrial applicability.In this paper,a set of stable and high-precision mobile robot positioning system is obtained by studying the construction and location of artificial landmark maps and the global positioning of mobile robots.