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数控机床进给系统惯量识别及控制器参数校准研究
The Study for Inertia Identification and Self-tuning of Controller Parameter of Numerical Control Machine Feeding System
【作者】 张志锋;
【导师】 郭庆鼎;
【作者基本信息】 沈阳工业大学 , 电力电子与电力传动, 2007, 硕士
【摘要】 数控机床以自动化程度高、柔性好、加工精度高等优点在现代制造业特别是复杂零件加工中得到广泛应用,并得到迅速的发展和普及。数控机床的加工精度是衡量数控机床工作性能的重要指标,体现着机械制造业的制造能力和发展水平,也是整个国家科技和工业水平的重要标志之一。而数控机床的加工精度在很大程度上取决于其伺服进给系统的精度。永磁同步电动机(PMSM)以其体积小、效率高、可靠性好以及对环境的适应性强等诸多优点,在各种高性能的数控机床伺服进给系统中得到了广泛应用。永磁同步电动机伺服进给系统受机械参数变化影响较大,若不及时对其控制器进行调整,会使控制系统性能变坏,甚至不稳定等一系列问题。这里的机械参数主要是指系统的转动惯量(包括电机转子转动惯量和负载的转动惯量)和负载转矩两部分。本文采用计算机仿真的方式对永磁同步电动机伺服进给系统进行了研究。首先,介绍了永磁同步电动机的数学模型和永磁同步电动机的矢量控制原理,确立了i_d=0的转子磁场定向的电流、速度双闭环的矢量控制方案。接着,按照工程上通常采用的方法把系统的电流环校正成典型Ⅰ型系统,根据部分模型匹配法设计了系统的速度控制器。然后,采用离散的模型参考自适应辨识算法和带有遗忘因子的递推最小二乘法两种方法在线辨识了系统的惯量,用辨识得到的惯量对系统的速度控制器进行在线校正研究,仿真结果表明该伺服系统在本身的参数变化较大时,仍然具有良好的动静态性能。负载转矩的变化对系统性能的影响也非常明显,需要在线进行动态补偿。但负载转矩同转动惯量一样,也是一个很难直接测量的非电物理量,需进行在线辨识。本文根据采用具有遗忘因子的递推最小二乘法辨识得到的负载转矩,对系统的电流进行了前馈补偿,有效地提高了伺服进给系统的抗干扰性能,增强了系统鲁棒性。最后对全文进行了总结。
【Abstract】 Since numerical control machine has good performance in degree of automation, flexibility and high precision, it has been applied widely and further developed in modern manufacturing, especially, in complex part machining. The machining precision of numerical control machine is important performance index of numerical control machine, represents manufacture ability and developing level of manufacturing and is also one of most important symbol of all nation science and technology and industrialization level. The precision numerical control machine mostly depends on the precision of the servo feeding system. Permanent magnet synchronous motor (PMSM) has been widely used in high performance numerical control machine servo feeding system for its advantages, such as compactness, high efficiency, reliability and suitability to environment.The performance of PMSM servo feeding system is highly influenced by uncertainties of unpredictable variation of mechanical parameters and external load disturbances. In order to enhance the system static and dynamic performances. it is necessary to identify the mechanical parameters and auto-tune the speed controller.The thesis studies PMSM servo feeding system based on computer simulation. First, the mathematical model of PMSM and basic theory of vector control are introduced, the vector control scheme (i_d=0) based on rotor field orientation and current and speed double loops control scheme for PMSM servo system are made certain. Second, current controller and speed controller are designed respectively based on the method of engineering design and the method of part model matching. Then, the inertia of system is identified respectively based on model reference self adapting identification and recursive least square method with oblivious gene. And the scheme for auto-tuning the speed controller based on the identified inertia is presented as well. The simulation results prove that the PMSM servo system has good dynamic and static performance when the inertia varies. The load torque is also difficult to be measured directly, so it needed to be online identified. This dissertation adopt a compensate control algorithm, which could dynamically compensate load torque variation. The simulation results show that, this compensatory control strategy can improve the anti-disturbance and enhance robustness of serve feeding system. A summery of whole thesis is given in the end.
【Key words】 Numerical Control Machine; AC Servo System; Inertia Identification; Self-tuning Control; Load Torque Identification;
- 【网络出版投稿人】 沈阳工业大学 【网络出版年期】2007年 05期
- 【分类号】TG659
- 【被引频次】6
- 【下载频次】482