【作者】 宋玉；

【导师】 马术文；

【作者基本信息】 西南交通大学 ， 机械制造及其自动化， 2010， 硕士

【摘要】 目前,在机械制造行业中广泛采用了数控技术对机械零件进行加工。加工过程中数控机床的稳定性和响应性对机械加工有着重要的影响,基于以上原因在机床动态性能方面就需要深入研究,机床动态特性分析是研究机床抵抗动态作用力的能力,机床抗振性能越好加工性能就越好；伺服进给系统不仅对机床的稳定性有影响,对响应性方面的影响也非常重要,高效、稳定的伺服进给系统能够很好的提高机床的加工性能。针对应用数控机床在机械加工中伺服进给系统的稳定性,以及响应性等方面的问题。论文主要对以下方面进行了研究：(1)对伺服系统组成进行分析,建立了伺服驱动环节以及机械传动装置的数学模型,建立较完整的伺服进给系统的数学模型；(2)对伺服系统模型进行简化,分析伺服系统特性对加工精度的影响,并依据伺服特性分析结果分析机床动态特性方面受到的影响；(3)以实验室自制三轴联动数控机床进给伺服系统为对象,计算伺服进给系统相关参数,对伺服进给系统进行SIMULINK建模并进行仿真；(4)对比PID控制器多种优化方法,运用遗传算法对伺服系统的PID控制器参数进行优化研究,分别通过实例加工和PID校正系统仿真曲线,评价伺服系统PID控制器参数优化结果；通过以上工作建立了正确的伺服进给系统模型,运用遗传算法对伺服系统PID控制器参数进行优化,一方面通过实例加工,对比PID控制器参数优化前后的加工效果,另一方面通过对比PID校正系统仿真曲线,说明优化后PID控制器参数对提高伺服进给系统性能有一定的作用。更多还原

【Abstract】 CNC technology is widely used in mechanical manufacturing industry at present. The stability and responsiveness of machine tool in processing are very important. Due to these reasons, the dynamic characteristic of machine tool is required to study. The dynamic analysis of machine tool is mainly to study the capacity which against the dynamic force. The better performance of machine tool against vibration makes the machine tool work better. Servo feed system affects not only the stability of machine tool, but also the response of machine tool. Efficient and stable servo feed system can improve machine process ability. The aim of this thesis is to study the stability and the response of servo system in processing. The following aspects are studied in this thesis:(1)Composition unit of the servo system are analyzed, the mathematical model of servo drives part and mechanical transmission are established. A complete servo feed system mathematical model is established;(2)The mathematical model of the servo system is simplified. The influence of Servo system characteristics on the machining accuracy is analyzed. According to the result, the dynamic characteristics of machine tool are analyzed;(3) Some parameters of the servo system which are from the bench of self-made three-axis NC machining tool are calculated. The parameters are designed to parameterization. Then the parameters are calculated to adapt different machine tools and servomotors. SIMULINK is used to establish model and simulation.(4)Methods of PID controller optimizing are compared. The PID parameters are optimized by using genetic algorithm. The actual process is done on a self-made three-axis NC machine tool and simulation curve of two different PID controller parameters are compared to evaluate the optimization results.The right servo system model is gained. The PID controller parameters of servo system are optimized by using genetic algorithm. On one side, the cutting surface is compared to show the difference of the effect of optimizing. On the other side, simulation curve of two different PID controller parameters are compared. The result shows that PID parameters optimizing can make the servo system work better.更多还原