Design And Trajectory-Planning Of Automatic Load-Unload Equipment For The Stone Strips Mill

Stone plates are widely applied in many fields(construction, decoration, etc.)for excellent physical and chemical properties. With the rapid development of stone industry, the Chinese stone processing machinery has been greatly promoted. As an important part of the stone processing link, stone strip mill market continues to increase. Many automatic and intelligent load-unload equipments for the mill of stone strps have been developed abroad, but especially expensive. For the times being, lots of domestic stone machinery enterprises have developed some automatic load-unload equipments for stone slabs by imitating foreign equipments. However, their function and performance is not so good as abroad equipments. At present, most small and medium-sized enterprises in China generally use artificial or simple lifting device to realize load-unload operation of stone slabs. The backward load-unload way of stone slab has been a big obstacle in the process of our stone processing intellectualization. Besides, bad work in stone processing workshop, conditions Together with, heavy labor intensity and rising labor cost tremendously weakens the competitiveness of the enterprises. It has great social benefits and economic benefits to develop a set of automatic load-unload equipment for mill of stone strips, which is simple, secure, stable and intelligent.The automatic load-unload equipment for mill of stone strips in this paper was designed according to the load-unload operation space of stone strip mill, technology characteristics, production equipments layout and present automatic load-unload equipments for stone strips both of domestic and overseas. Made finite element static analysis and optimization design to some key structures. For the bad load-unload pace and running state of present automatic load-unload equipment for mill of stone strips, we made kinematics analysis to the equipment and planned the trajectory of end effector. In this way, its movement characteristic and work efficiency was improved.On the base of design requirements of the load-unload equipment, the principle of FA and modular design, we completed overall scheme of the load-unload equipment, including end actuator module, motion module, frame module, test module and control module. End actuator achieves the revolve movement through a cylinder. Thus the equipment both can satisfy the load-unload requirements of horizontally and vertically placed stone slabs. We apply foam suckers in the design of end actuator, so that the processed stone slab surface will not be scratched; The suckers are arranged by 4x6 matrix and independent of each other in order to adapt to load-unload slabs of different sizes and achieve high safety coefficient. Cantilever frame saves space and has strong adaptability. The design of visual position detection system and "PC+motion control card" for the load-unload equipment realizes automation and intelligentization. The finite element model of frame is setted up through Solidworks. Frame structure was multi-objective optimized by setting the optimization parameters and goals through the DOE module of ANSYS Workbench. As a result, frame quality was reduced by 17.41% under the guarantee of the strength and stiffness of frame.For the foundation of trajectory planning and control of end actuator, to all the coordinate systems of every motion part in the load-unload equipment are established based on D-H method. In rectangular coordinate we respectively apply sine acceleration model, a polynomial acceleration model and modified trapezoidal acceleration model trajectory planning to X/Y direction translation and Z axis rotation of end executor following both right door path and arc transition door path. Adams simulation and Matlab simulation show that all of the three kinds of acceleration model can realize that at the of the displacement, velocity and acceleration of end actuator continuously change, smoothly transit over time. Modified trapezoidal acceleration model has optimal time and the highest work efficiency; The arc transition door path can avoid obstacle (roller) and the shaking of end executor in the corner, showing good dynamic characteristics.