精密机械平台摩擦特性的建模和补偿方法

发布时间：2018-03-07 12:46

本文选题：精密机械平台　切入点：重力补偿气缸　出处：《哈尔滨工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：本课题来源于国家科技重大专项“极大规模集成电路制造装备与成套工艺专项”[1],子项目“可变狭缝系统”。可变狭缝系统为光刻机曝光过程中的重要部分,其曝光过程中,竖直方向刀片组需要对重力进行补偿,本专项选用的是气缸重力补偿装置,虽然气缸运动过程中产生的摩擦力较小,但是考虑到平台的精度,对其存在的摩擦进行补偿还是很有必要的。本课题针对其狭缝扫描系统中重力补偿气缸的摩擦力问题,较深入的研究精密平台精密平台克服摩擦的理论和方法。首先,根据实际的工程背景,抽离出可变狭缝系统竖直方向重力补偿部分,根据课题的各项指标要求,对元器件进行选型,并完成该部分实际平台的搭建。之后为验证自主搭建的重力补偿系统的可行性,在该系统平台上进行初步的控制调试及实验。在此过程中,发现重力补偿气缸运动过程中产生的摩擦对实验的精度有较大的影响。其次,针对本课题的重点研究对象,即重力补偿气缸,进行研究。首先从气缸的机械结构入手,讨论重力补偿气缸的组成及工作过程,然后通过理论推导得出所选气缸的机理模型,最后对建立的模型进行仿真,探究模型在加入外界扰动的情况下,气缸的位置、内压、内部流量等的变化,得出仿真结果。针对LuGre摩擦模型进行仿真,探究LuGre摩擦模型的各个待估参数对系统的影响,得出的仿真结论为后文的参数辨识过程打下良好基础。再次,接下来,分别用最小二乘法,非线性最小二乘法,及遗传算法对摩擦参数进行辨识,对不同方法得到的辨识结果进行比较,对不同的辨识方法进行优劣势分析。然后通过实验,测得原始数据,通过测量驱动电流的间接方法得到系统中实际的摩擦力,并通过遗传算法,完成对实际系统中摩擦力模型的参数辨识。最后,通过实验对上文提出的方法进行验证,并且通过实验完成对实际系统中的摩擦力的补偿。验证了前文提出的摩擦力模型对实际系统的适用性,以及前文提出的辨识方法的辨识精确性。最后通过对比,选用实用性较高、控制效果较好的前馈控制方法,完成对实际系统重力补偿气缸部分存在的摩擦力的补偿,提高了系统的控制精度,完成最初的指标要求。
[Abstract]:This subject comes from the national science and technology major project, "maximum scale Integrated Circuit Manufacturing equipment and complete process Project" [1], a sub-item "variable slit system". The variable slit system is an important part of the exposure process of the lithography machine, and in the exposure process, the variable slit system is an important part in the exposure process of the lithography machine. The vertical blade group needs to compensate gravity. This special type is the cylinder gravity compensation device. Although the friction produced during the cylinder movement is small, the accuracy of the platform is considered. It is necessary to compensate the existing friction. Aiming at the friction problem of the cylinder compensated by gravity in the slit scanning system, the theory and method of the precision platform to overcome friction are studied in this paper. According to the actual engineering background, the vertical gravity compensation part of the variable slit system is extracted, and the components are selected according to the requirements of the project. In order to verify the feasibility of the self-built gravity compensation system, the preliminary control debugging and experiment are carried out on the platform. It is found that the friction produced during the motion of the gravity compensated cylinder has a great influence on the precision of the experiment. Secondly, the main research object of this subject, that is, the gravity compensated cylinder, is studied. Firstly, the mechanical structure of the cylinder is introduced. The composition and working process of the gravity compensation cylinder are discussed. Then the mechanism model of the selected cylinder is derived by theoretical derivation. Finally, the model is simulated to explore the position and internal pressure of the cylinder when the external disturbance is added to the model. According to the change of internal flow rate and so on, the simulation results are obtained. According to the simulation of LuGre friction model, the influence of the estimated parameters of LuGre friction model on the system is explored. The simulation results lay a good foundation for the parameter identification process in the following chapters. Then, the friction parameters are identified by least square method, nonlinear least square method and genetic algorithm respectively. The identification results obtained by different methods are compared, and the advantages and disadvantages of different identification methods are analyzed. The actual friction force in the system is obtained by measuring the driving current indirectly, and the parameter identification of the friction force model in the actual system is completed by genetic algorithm. Finally, The proposed method is verified by experiments, and the friction force in the actual system is compensated by experiments. The applicability of the proposed friction model to the actual system is verified. Finally, through comparison, the feedforward control method, which has high practicability and good control effect, is used to compensate the friction in the cylinder part of gravity compensation system. The control precision of the system is improved and the initial target requirement is fulfilled.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN305.7

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