Study Of Intelligent Cylindrical Traverse Grinding

Dissertation Subject: Study of Intelligent Cylindrical Traverse GrindingSpecialty: Mechanical Engineering and AutomationSupervisor: Prof. Wang Longshan Modern advanced manufacturing technique is developing towards to FlexibleManufacturing System (FMS), Computer Integration Manufacture System (CIMS)and Intelligent Manufacture System (IMS). The customer demands that theproduction performance be perfect, reliable, and possibly a one-time surface finishmachining. So not only is the manufacturing system required to be with highefficiency and low cost of raw material and energy, but also the finished productionis with high size accuracy, low surface roughness and surface integrality. Thegrinding result directly affects the final quality and performance of product becausethe grinding is usually the ultimate machining procedure. But the grinding processis non-linearity and randomcity with too many influence factors; the accuracymathematical model cannot be built, and the traditional control method cannotresolve the control problem during the grinding. At present, adjusting the grindingprocess is strongly relied on the operator's experience and skill. The grinding is oneof the key technologies that constraints some elements of advanced technologydevelopment. Hence, intelligent grinding is the development tendency. In this dissertation, the cylindrical traverse grinding, which is the universalmanner in the factory, is deeply studied. The grinding force model, workpiecedeflection model, the wheel wear model and workpiece size model are built.Especially, the intelligent theory is introduced to grinding process. And theintelligent model of workpiece surface roughness and size and the control of thedeflection, the roughness and the size can be realized.1. Variable Parameter Optimization Adapt Control of Workpiece Deformationfor Cylindrical Traverse Grinding In the cylindrical traverse grinding, especially for the slender cylindrical workpiece, theworkpiece will be deformed under the grinding force. Furthermore, the deformation changeswith the wheel position. One of the problems of traverse grinding is how to reduce thedeformation as more as possible. In the conventional traverse grinding process, the workpiecevelocity (Vw) and table feed velocity (Vf) are selected the values that can keep the workpiecedeflection of the smallest stiffness position within the error limit, and the cut depth (?) is also 1摘 要made as small as possible. But the selected Vw and Vf are not optimal to the others biggerstiffness positions. Additionally, minimizing the shape and size error caused by the wheel wearwill require dressing to be performed frequently and this will result in waste of time and money.Studies on workpiece steady-based control system showed that controlling the steadies tocompensate for the workpiece deformation could greatly reduce the shape error. However, thiswould require more workpiece steadies to be present sometimes and the process was relativelycomplex. Therefore, basing on the grinding force model and workpiece deflection model,breaking the traditional constant velocity control method, this dissertation proposesa variable parameter optimization adapt control strategy. We can change Vw and Vfto control workpiece deflection with the wheel grinding position moving along theworkpiece axis because there exists the fix quantify relation between force,workpiece deflection, Vw and Vf. The grinding time is adopted to be anoptimization function and the optimal values of Vw and Vf to certain wheel reactionpoint can be obtained by optimize program. Actually, there exist many uncertain factorsduring the grinding process, So an optimization self-adaptive control system is used inthis dissertation.2. Workpiece Size Intelligent Prediction And Control For Cylindrical Traverse Grinding In order to control workpiece size, the size form mechanism is deeply studie...