Hierarcical Control Of Complex Manufacturing Processes

With the development of industry and control theory,in order to maximize profits,manufacturers' requirements for manufacturing efficiency and yield are increasing day by day.As an important part of mechanical manufacturing,extrusion manufacturing is widely used in mechanical manufacturing.Compared with other manufacturing processes,extrusion manufacturing can create very complex cross-sections,but the process of extrusion manufacturing is very complicated,and the requirements for control technology are relatively high.Under such requirements,hierarchical control,as a control technology with superior performance,can ensure that the equipment manufactured and manufactured has excellent manufacturing quality and reliable manufacturing capabilities.In this paper,first of all,through a new hierarchical contour control method of a motion control system with multiple targets,the targets are assigned to two decision levels,a higher level of axis synchronization and a bottom level of single axis tracking,to make the internal model The principle is combined with optimal control and extended for force/position control of the end milling process.Combining the relevant theory of hierarchical control,hierarchical optimal control hierarchical controller is introduced to control complex systems with constantly changing objectives.The controller includes a process level for predicting the controller based on a non-linear model and a monitoring level for automatically controlling target changes during the extrusion manufacturing process.At the same time,through simulation research on the adjustment axis position and machining force error,the higher level of machining force adjustment is propagated to the bottom layer.The optimal control technology with cost function is used to weight the position error,machining force error and control signal usage of each axis,and the performance of the controller is verified through a simulation case study.In order to analyze the impact of changes in emphasis on the axis position and machining force tracking,nine simulation studies were conducted,in which the highly emphasized axis tracking increased to 5(that is,highly emphasized),and it was found that as the axis position error stabilization time increases,the relatively constant contour The error magnitude and transient machining force error are reduced accordingly.In this paper,first of all,through a new hierarchical contour control of a multi-target motion control system,this study found that for motion control systems,when contour tracking is very important,even when the axial control signal is saturated,The controller can also reduce contour errors.In addition,during the processing of sharp edges,excessive squeezing force will cause breakage.By using the hierarchical controller designed in this paper,the squeezing force can be guaranteed without sacrificing position tracking performance at the same time.