| Compared with the rapid development of container yard in the field of intelligence and automation,the automation of bulk cargo yard has been seriously lag behind.Operation in the bulk cargo yard still relies on the traditional manual operation.Among them,the lack of accurate measurement and management of the bulk pile data is one of main factors.The bulk cargo yard map system acts as the eye of the entire automation system.It scans the pile and generates the height contour profile,supply data basis and operation security for automation.The terminal production management system generates the task plan based on the contour height data and prepare the operation path,while the PLC control system of the machine can update the path based on real-time contour data in the course of operation.Nowadays,the research on bulk cargo yard map system has become an important issue.In this thesis,we study the key technologies of the bulk cargo yard map system in details such as 3D measurement technology,3D data storage,map generation and visualization,height contour fitting.We select laser ranging as the technical means of test scheme by studying the basic principle and application cases of laser ranging and stereo vision,and comparing the advantages and disadvantages of the two applications in bulk cargo yard.We select the grid method to store the height contour data by studying the 3D data model and the actual situation in the test yard.By studying the scanning data generation process and laser scanner spatial movement,we design the conversion formula to obtain global 3D coordinates to update the yard map,and use OPENGL to visualize the map contour.By studying the spatial interpolation theory,we design the height fitting algorithm to update grids and solve the problems that discrete distribution of scanning data points and the scanning blind area causes scanning area can’t be completely updated.Based on the research on the key technologies,we design a set of test system in this thesis.The test system is installed in the bulk cargo yard map locating in Rizhao,Shandong which includes one stacker and one reclaimer.We test the effect in the two yards.After data calibration and map accuracy verification,error of contour accuracy in the X and Y axis is less than 30 cm,while error in the Z axis is less than 20 cm.The accuracy of map contour can meet the needs of automatic stacking and reclaiming operation.Finally,the test system is involved in the automatic stacking and reclaiming operation in empty and heavy load. |
