【作者】 张恒；

【导师】 陈志华；

【作者基本信息】 国防科学技术大学 ， 机械工程， 2006， 硕士

【摘要】 异形截面零件的车削是活塞加工的关键工序之一。伺服刀架的跟踪性能对异形截面的车削精度起着极其重要的作用。在最大限度地保证伺服刀架的闭环反馈控制精度的基础上,采用前馈控制的方法将进一步提高异形截面的车削精度。本文就如何在实际车削加工中应用前馈控制方法进行研究,主要内容如下:1.介绍了活塞数控加工系统总体结构,并就其中的伺服刀架的闭环反馈控制系统结构和跟踪误差模型进行了重点分析。2.对伺服刀架的闭环反馈控制系统进行连续传递函数辨识。在此基础上针对不同主轴转速确定采样时间,得到相应的系统离散传递函数,为数字前馈控制器的设计奠定基础。3.对前面辨识得到的离散系统用零相位误差跟踪控制器进行前馈控制。针对活塞加工的特点,提出了“相位线性分离―再辨识”的前馈控制器设计方法,拓展了零相位误差跟踪控制器在实际车削加工中的适用范围。仿真与实际车削表明,采用所设计的前馈控制器后,可以达到提高异形截面零件加工精度的目的。更多还原

【Abstract】 The machining of noncircular section is one of the key working procedures of piston machining. The tracking capability of servo tool plays an important role in machining accuracy of noncircular section. On the base of ensuring the closed loop feedback accuracy in most extent, taking feed-forward control method can further improve the machining accuracy. How to apply this control method to the machine practice is discussed in this dissertation, and it includes such contents as follows:1. Introducing the whole configuration of piston machining system, and making a particular analysis on closed loop feedback control system of servo tool and err tracking model.2. Achieving the continuous model of the closed loop feedback control system, and then getting the discrete model function according to the different discrete time. This supplies a basic condition for the next step.3. Taking zero phase err track controller for the discrete system identified previously. Based on piston machining characters putting forward the technique“linear- phase-separating- identification”to design the feed-forward controller, that carving out the use of the zero phase err track controller.Simulation and actual machining proved that using the feed-forward controller can improve the machining accuracy of the noncircular section.更多还原