A Research On Vision Based Laser Measurement System Calibration Method

Simultaneous localization and mapping of the mobile robot is a widely researched area. In practice, the mobile robot needs to set up a local map to carry out navigation and self-positioning in a completely unknown environment, under the conditions of uncertainties in its own position.It's a most important and basic problem for the mobile robot to localize itself by the means of sensors, and it's absolutely necessary to make fusion by accumulating information form single sensor. Therefore, information fusion for sensors and advanced arithmetic play an important role for the robot's high sensitivity and robustness.Distance detection provides 3D information of the surroundings for a mobile robot, being an inseparable part for the overall system. LMS has a higher accuracy and a better orientation, and almost with no influence from the visible light, so, its very suitable for it to be used in a complicated environment, and that's the reason for its widely adoption in the mobile robot research.LMS(Laser Measurement System) is calibrated by the vision system in this research, with an objection to fuse the data received by the LMS and those from the CCD cameras, which is the base for the later SLAM work.A data acquiring and plotting system is set up in this article. The data acquiring system has such functions as configuring the LMS, including its view field, angle resolution, and measuring modes, also, it will save the data continuously or by frames according to the user's requirements. It could show the plot of those data on the screen, being convenient for the user to observe on real time. The plotting system can be used to show the data in a polar frame, so the objects with interest can be selected easily.Besides, the effects of the reflectivity of the objects and system itself on measurements are also analyzed in this article. It's suggested that some special features of the reflectivity about certain materials can be utilized to tell distinguish different objects.Initial calibration is fulfilled in this article, that is, the matching of detected points between the LMS coordinates and the CCD coordinates.