Aiming at some problems existing in the development and industrialization of intelligent autonomous mobile robot, the SLAM mobile robot platform is designed and developed in this paper. Cartographer is used as the SLAM algorithm to realize the mapping and localization of the robot in the unknown environment. What's more, the new hardware design architecture is proposed, and the bottom control module is designed to be applied to the autonomous mobile robot. On the one hand, the design can reduce the workload of the non-algorithm part of the main control unit and improve the real-time of mapping. On the other hand, it solves the problem of communication clogging and enhances the compatibility of the system. Finally, an autonomous test platform is built to test the mapping and localization functions of the robot. The results of mapping, computational complexity and robustness of Cartographer SLAM and Hector SLAM algorithms are analyzed.
The flow state and velocity distribution of liquid metal in the FC-Mold and the influence rules by the magnetic flux density have been investigated when electromagnetic brake adopted, applying mercury as medium to simulate molten steel in the continuous casting process. The velocity measurement has been completed by the Ultrasonic Doppler Velocimeter (UDV) under various magnetic distribution and the influence laws of magnetic flux density on the liquid metal flow in the mold has been analyzed. The experimental results indicate that, when the upper and lower magnetic flux density is 0.18T and 0.5T respectively, a preferable control effect can be obtained, not only the free surface fluctuation can be compressed, but also a plug flow can be rapidly formed.
The hot preflex cooling and compound straightening are the last two consecutive deformation processes and determine the straightness, residual stress and cross-sectional size for fabricating hundred-meter heavy rail products. The compound straightening process needs to be adjusted by the preflex cooling status. For studying the straightness, residual stress and cross-sectional size of heavy rail products, the preflex cooling model (including the residual stress) of heavy rail after cooling should be taken as straightening model for studying the compound straightening. In this paper, the results by ANSYS implicit analysis (geometry model and stress state of the cold heavy rail) is fully imported to the compound straightening by ANSYS/LS-DYNA explicit analysis through an implicit-explicit conversion method, which resolved the connection problem of coupling and analysis models for solving complex models in multi-physical fields. It is very significant for solving the similar problems in engineering.
Abstract. The initial cooling temperature has important effect on the bending change and section size of rolled heavy rail, when rolled heavy rail is on the cooling bed for natural cooling. In the paper, the heat-stress couple method is adopted to carry on numerical simulation to cooling process of 60kg/m U75V heavy rail, and we has obtained the bending change value and section size of rolled heavy rail in different initial cooling temperature. The study is of great reference value on the design of cooling bed which is for hundred-meter high speed heavy rail and the formulation of cooling technological parameters.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.