【作者】 李超；

【导师】 孔令飞；

【作者基本信息】 西安理工大学 ， 机械电子工程， 2018， 硕士

【摘要】 高效精密、成本低廉、环境友好的深孔钻削技术是新能源、军工、航空航天等关键制造领域的迫切需要。由于深孔钻削技术的复杂性,如何在保证深孔钻削系统稳定的前提下实现对刀具系统动态特性的精准、实时控制,进而加工出理想品质的深孔制件已成为该领域研究的热点问题。考虑到实际深孔钻削中加工孔的圆度误差与刀具振动模态有着最为直接的联系,本文提出了一种基于独立模态空间特征的深孔刀具振动抑制算法。以Euler-Bernoulli梁-轴有限元模型为基础,通过对可变刚度/阻尼刀具系统动力学方程进行模态凝聚与解耦,将刀具在物理空间的振动信息转入到模态空间,构建了独立模态空间的深孔刀具系统状态控制方程,避免了传统物理空间所需控制参量多且相互耦合的缺陷,进而为深孔钻削刀具系统振动状态的实时控制奠定了基础。针对刀具振动模态的实时控制问题,采用最优模态性能指标锁定要摧毁或抑制的模态参数,并结合Luenberger模态状态观测器,将刀具振动的模态位移和模态加速度信息引入到极点配置修正后的反馈增益矩阵中,计算获得了对目标振动模态“精确打击”的实际制振控制力,从而实现了带有目标性的刀具系统振动抑制控制,提升了深孔钻削加工过程中的稳定性。以此为基础,运用模态实验对所建立的深孔刀具动力学方程进行了验证,并通过大量的实验数据验证了本文所构建的刀具振动主动式控制算法的有效性与可行性,这些将为深孔钻削加工中深孔制件圆度品质的主动控制奠定了基础。更多还原

【Abstract】 High-precision,low-cost,and environmentally-friendly deep-hole drilling technology is an urgent need in Chinese rapidly developing new energy,military,and other key areas.Due to the complexity of the deep hole drilling technology,how to achieve precise control of the dynamic characteristics of the tool system under the premise of guaranteeing that the deep hole drilling system is not destabilized,and then processing the ideal quality of the deep hole work pieces has become the hottest research in this field.Considering the direct correlation between the roundness error of hole and vibration mode of cutting tool in deep hole machining,a novel control strategy was proposed for suppressing vibration of tool system based on independence mode characteristics.On the basis of Timoshenko finite element model,the independence state control equations of drilling tool system which included the vibration suppressing damper with variable stiffness or damping were established via modes reducing and decoupling,so that a series of physical space information of tool dynamic model can be transferred into modes state space to overcome the problems of excessive control parameters and intercoupling effect arising in traditional physical space.With the target of real-time suppressing vibration,optimal mode performance indexes were fixed as the object of destroying or suppressing modes.At the same time,mode displacement and mode acceleration in Luenberger state observer were introduced into feedback gain matrix modified by generalised pole assignment method,and consequently,"precision-strike" mode force needed by physical space can be obtained against the object of vibrating mode.Finally,a series of experimental investigations are carried out to confirm the feasible and effectiveness of the independence mode state equations of drilling tool system,and simultaneously,roundness errors of hole were calculated numerically under the different magnitude conditions of mode force.Whether experimental or computation results indicate that this method proposed in this paper will be able to be a possibility of targeted suppressing the tool vibration and controlling hole roundness error actively in deep hole drilling process.更多还原