Optimal Control Method For Vibration Suppression Of Deep Hole Drilling Tools

Deep-hole drilling technology with high precision,high efficiency,and low cost are imperative in aerospace,new energy equipment manufacturing and high-tech industries.But so far,the manufacturing methods of this type of parts are still mainly traditional deep hole drilling,and the controllability of h ole quality is poor.The control of the quality of deep hole drilling is essentially a "dynamic" issue,which is closely related to various interference factors that affect the vibration characteristics of the tool system during the drilling.Although people have adopted a variety of methods such as the stable domain method,passive control and active control to reduce harmful vibrations in the processing process,no satisfactory solution has been obtained so far.Therefore,how to control the dynamic behavior of the tool accurately and at low cost,and then form deep-hole parts with predetermined machining quality has become a hot issue in deep-hole drilling research.Since the quality of deep hole machining is closely related to the vibration mode of the tool,this paper establishes a vibration suppression algorithm for deep hole drilling tools based on the independent modal space characteristics.Through the modal decoupling and truncation of the dynamic equation of the deep hole drilling tool system,the vibration characteristics of the tool in the physical space are transferred to the modal space,and the modal displacement and veloc ity information estimated by the modal filter are introduced To the feedback gain matrix,a real-time"precise strike" framework for harmful vibration modes of deep hole tools is built,thereby avoiding the defects of many control parameters and mutual coupling required in the traditional physical space.In order to improve the observability and controllability in modal control,a sensor/damper position optimization algorithm based on tool system modal characteristic is proposed.The algorithm combines effective independent method(EFI),modal assurance criterion(MAC)and minimum spillover method(MSM),which not only effectively increases the reliability of the independent modal control system,but also greatly reduces the cost of tool vibration suppression On this basis,a vibration suppression algorithm for deep hole drilling tools based on independent modal space features was constructed,and a modal suppression verification experiment system was built using the dSPACE software and hardware system.Finally,by applying vibration control forces to different modes of the tool system,the effective control of the roundness error of the inner hole of the machined part is achieved,and the effectiveness of the sensor/damper position optimization algorithm and vibration control architecture in this paper is confirmed.This research not only provides technical guarantee for the targeted regulation of hole quality in actual deep hole processing,but also provides a useful reference for solving the vibration suppression problems of other weak stiffness structures(such as cantilever beams,plates,shells,blades,etc.).