能动磨盘动态面形检测研究
发布时间：2019-05-18 16:57
【摘要】：在大口径非球面镜加工方法中,能动磨盘加工技术具有高效率、高精度、高智能化等特点,应用此技术,一系列大口径非球面镜得以高效高质量地完成。不同于传统加工工艺中的刚性磨盘,能动磨盘利用弹性薄板在受到外力驱动时产生的规律形变进行实时变形,以保持在平移且旋转地研抛镜面时磨盘表面与镜面面形实时匹配,进而在提高加工效率的同时抑制镜面中高频误差。在能动磨盘被用于加工镜面前,需要对其变形进行标定,以保证加工时对磨盘面形的精确控制。常用的标定方法为接触式位移传感器阵列测量法,即应用几十个位移传感器组成点阵,将磨盘盘面接触传感器阵列,分别记录磨盘在变形前后的面形值,两者相减即得到磨盘的面形变化。这种方法可以测量能动磨盘的静态面形,但不能反应磨盘在加工中的实际面形变化与面形精度,本文在此已有的能动磨盘面形检测技术的基础之上,针对能动磨盘变形中的动态面形开展了深入研究,主要在以下几个方面取得了突破性进展:(1)针对基于微位移传感器的接触式磨盘面形测量方法,分析了检测系统的各项误差及其对检测结果的影响。得出结论,检测系统中传感器检测时的球头误差属于系统误差,可以在磨盘面形数据处理时补偿;而传感器安装位置、安装角度误差属于随机误差,对检测的影响在精度范围以内;当前检测系统的传感器数目能够以较高地精度还原面形。(2)对基于影响函数的能动磨盘面形控制方法进行了总结,应用磨盘面形检测系统测量了1m能动磨盘上18个驱动器的影响函数,对给定位置处能动磨盘的静态面形进行了标定和变形验证。基于Zernike多项式提出了磨盘变形控制过程中高频误差抑制方法,给出了具体的误差补偿过程,分析结果表明,经过补偿能动磨盘的控制面形精度可以提高10%~20%,并通过实验验证了补偿方法的有效性。(3)建立了能动磨盘不同面形精度情况下的去除效率模型并进行了仿真,验证了磨盘面形精度对加工的重要影响,证明了动态测量能动磨盘面形的重要性,并基于结构函数提出了能动磨盘的面形评价指标,推导了用于快速计算的结构函数计算公式。不同于常见的基于均方根的磨盘面形评价体系,结构函数表征方法将磨盘面形与空间尺寸联系起来,更能够准确地反应出磨盘的面形状态。(4)基于FPGA和USB通信实现了能动磨盘面形动态检测系统的研制。通过解决能动磨盘面形检测过程中各传感器数值与磨盘所处镜面位置之间同步性的问题,将磨盘的面形测量由原始的静态测量改进为变化中的动态测量。采集系统能够定量的给出磨盘在加工中某位置处的动态面形,以便计算磨盘面形在任意位置处与理论面形之间的误差,可以分析以至改善磨盘面形精度,通过实验验证了采集系统的采样频率可以保证对磨盘动态面形的精确采集。(5)实际测量了磨盘加工过程中的动态面形变化,得到了不同转速情况下的磨盘面形动态变化,将测量结果与理论镜面面形值进行比对,分析了不同转速情况下的磨盘面形精度,为不同阶段采用不同旋转速度提供数据支撑,同时提出根据不同转速情况下的能动磨盘面形精度提高加工效率通过本文分析,首先验证了用于4m级主镜加工的能动磨盘静态面形精度可以满足加工要求,在此基础之上,得出了磨盘面形精度会随其转速的增加而稍微下降的结论,但不同于预期的结果,实验证明磨盘在较高速旋转加工时仍能保证较高的面形精度,说明在加工过程中可以根据不同的加工阶段选择不同的转速,一方面可以保证不同加工阶段所需的磨盘面形精度,另一方面可以提高加工效率。这为制定更智能化的加工策略提供数据支撑,有利于进一步挖掘能动磨盘的潜能。
[Abstract]:In a large-caliber non-spherical mirror proces method, that active disc processing technology has the characteristics of high efficiency, high precision, high intelligentization and the like, and the technology is applied, and a series of large-caliber non-spherical mirror can be effectively and high-quality. different from the rigid grinding disc in the traditional processing technology, the active grinding disc is subjected to real-time deformation by the regular deformation generated by the elastic thin plate when being driven by an external force, Furthermore, the high-frequency error in the mirror is suppressed while the processing efficiency is improved. The active grinding disc is used in the front of the processing mirror, and the deformation of the movable grinding disc needs to be calibrated to ensure the precise control of the surface shape of the grinding disc during the processing. The common calibration method is a contact type displacement sensor array measurement method, namely, a dot matrix is formed by applying dozens of displacement sensors, and the disc surface of the grinding disc is contacted with the sensor array, and the surface shape values of the grinding disc before and after deformation are respectively recorded, and the surface shape changes of the grinding disc are obtained by subtracting the two. The method can measure the static surface shape of the active grinding disc, but can not reflect the actual surface shape change and the surface shape precision of the grinding disc in the processing, The breakthrough progress has been made in the following aspects: (1) In view of the contact type grinding disc shape measurement method based on the micro-displacement sensor, the error of the detection system and its influence on the detection result are analyzed. It is concluded that the error of the ball head during the detection of the sensor in the detection system belongs to the system error, which can be compensated when the disc shape data is processed, and the position of the sensor installation and the installation angle error are random errors, and the influence on the detection is within the precision range; The number of sensors of the current detection system is capable of reducing the shape with a higher accuracy. (2) The shape control method of the active grinding disc based on the influence function is summarized, the influence function of the 18 actuators on the 1 m active grinding disc is measured by using the disc shape detection system, and the static surface shape of the active grinding disc at a given position is calibrated and the deformation verification is carried out. Based on Zernike polynomials, the method of high-frequency error suppression in the process of deformation control of the grinding disc is put forward, and the specific error compensation process is given. The results show that the accuracy of the control surface can be increased by 10% ~ 20%, and the effectiveness of the compensation method is verified by the experiment. (3) The efficiency model of the removal efficiency under different surface shape of the active grinding disc is established and the simulation is carried out, and the important influence of the surface shape precision on the processing is verified, and the importance of the dynamic measurement of the shape of the active grinding disc is proved. And based on the structural function, the surface shape evaluation index of the active grinding disc is put forward, and the calculation formula of the structure function for rapid calculation is derived. Different from the common root-mean-square-based grinding disc shape evaluation system, the structural function characterization method links the surface shape of the grinding disc with the space size, and can accurately reflect the surface shape state of the grinding disc. (4) The development of dynamic disc shape dynamic detection system is realized based on FPGA and USB communication. By solving the problem of the synchronism between each sensor value and the mirror position of the grinding disc during the surface shape detection of the active grinding disc, the surface shape measurement of the grinding disc is improved to the dynamic measurement in the change from the original static measurement. the collecting system can quantitatively give the dynamic surface shape of the grinding disc at a certain position in the processing, so as to calculate the error between the surface shape of the grinding disc and the theoretical surface shape at any position, and can be analyzed to improve the surface shape precision of the grinding disc, The experimental results show that the sampling frequency of the acquisition system can ensure the accurate acquisition of the dynamic shape of the grinding disc. (5) the dynamic surface shape change in the grinding disc processing process is actually measured, the surface shape dynamic change of the grinding disc under the condition of different rotating speed is obtained, the measurement result is compared with the theoretical mirror surface shape value, and the surface shape precision of the grinding disc under the condition of different rotating speeds is analyzed, in ord to provide data support for different rotation speed in different stages, and at that same time, the accuracy of the surface shape of the active grinding disc under the condition of different rotation speed is proposed, the processing efficiency is improved through the analysis, the static surface shape precision of the active grinding disc used for the processing of the 4m-level main mirror can be first verified, the processing requirement can be met, On the basis of this, it is concluded that the accuracy of the surface shape of the grinding disc will decrease slightly with the increase of the rotating speed, but different from the expected result, the experiment proves that the grinding disc can still guarantee the high surface shape precision when the grinding disc is processed at high speed. It is shown that different rotation speeds can be selected according to different processing stages in the machining process, and on the one hand, the accuracy of the surface shape required for different processing stages can be guaranteed, and the processing efficiency can be improved on the other hand. This provides data support for the development of more intelligent processing strategies, which is beneficial to further digging the potential of the active grinding disc.
【学位授予单位】：中国科学院研究生院（光电技术研究所）
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TG58;TG806
[Abstract]:In a large-caliber non-spherical mirror proces method, that active disc processing technology has the characteristics of high efficiency, high precision, high intelligentization and the like, and the technology is applied, and a series of large-caliber non-spherical mirror can be effectively and high-quality. different from the rigid grinding disc in the traditional processing technology, the active grinding disc is subjected to real-time deformation by the regular deformation generated by the elastic thin plate when being driven by an external force, Furthermore, the high-frequency error in the mirror is suppressed while the processing efficiency is improved. The active grinding disc is used in the front of the processing mirror, and the deformation of the movable grinding disc needs to be calibrated to ensure the precise control of the surface shape of the grinding disc during the processing. The common calibration method is a contact type displacement sensor array measurement method, namely, a dot matrix is formed by applying dozens of displacement sensors, and the disc surface of the grinding disc is contacted with the sensor array, and the surface shape values of the grinding disc before and after deformation are respectively recorded, and the surface shape changes of the grinding disc are obtained by subtracting the two. The method can measure the static surface shape of the active grinding disc, but can not reflect the actual surface shape change and the surface shape precision of the grinding disc in the processing, The breakthrough progress has been made in the following aspects: (1) In view of the contact type grinding disc shape measurement method based on the micro-displacement sensor, the error of the detection system and its influence on the detection result are analyzed. It is concluded that the error of the ball head during the detection of the sensor in the detection system belongs to the system error, which can be compensated when the disc shape data is processed, and the position of the sensor installation and the installation angle error are random errors, and the influence on the detection is within the precision range; The number of sensors of the current detection system is capable of reducing the shape with a higher accuracy. (2) The shape control method of the active grinding disc based on the influence function is summarized, the influence function of the 18 actuators on the 1 m active grinding disc is measured by using the disc shape detection system, and the static surface shape of the active grinding disc at a given position is calibrated and the deformation verification is carried out. Based on Zernike polynomials, the method of high-frequency error suppression in the process of deformation control of the grinding disc is put forward, and the specific error compensation process is given. The results show that the accuracy of the control surface can be increased by 10% ~ 20%, and the effectiveness of the compensation method is verified by the experiment. (3) The efficiency model of the removal efficiency under different surface shape of the active grinding disc is established and the simulation is carried out, and the important influence of the surface shape precision on the processing is verified, and the importance of the dynamic measurement of the shape of the active grinding disc is proved. And based on the structural function, the surface shape evaluation index of the active grinding disc is put forward, and the calculation formula of the structure function for rapid calculation is derived. Different from the common root-mean-square-based grinding disc shape evaluation system, the structural function characterization method links the surface shape of the grinding disc with the space size, and can accurately reflect the surface shape state of the grinding disc. (4) The development of dynamic disc shape dynamic detection system is realized based on FPGA and USB communication. By solving the problem of the synchronism between each sensor value and the mirror position of the grinding disc during the surface shape detection of the active grinding disc, the surface shape measurement of the grinding disc is improved to the dynamic measurement in the change from the original static measurement. the collecting system can quantitatively give the dynamic surface shape of the grinding disc at a certain position in the processing, so as to calculate the error between the surface shape of the grinding disc and the theoretical surface shape at any position, and can be analyzed to improve the surface shape precision of the grinding disc, The experimental results show that the sampling frequency of the acquisition system can ensure the accurate acquisition of the dynamic shape of the grinding disc. (5) the dynamic surface shape change in the grinding disc processing process is actually measured, the surface shape dynamic change of the grinding disc under the condition of different rotating speed is obtained, the measurement result is compared with the theoretical mirror surface shape value, and the surface shape precision of the grinding disc under the condition of different rotating speeds is analyzed, in ord to provide data support for different rotation speed in different stages, and at that same time, the accuracy of the surface shape of the active grinding disc under the condition of different rotation speed is proposed, the processing efficiency is improved through the analysis, the static surface shape precision of the active grinding disc used for the processing of the 4m-level main mirror can be first verified, the processing requirement can be met, On the basis of this, it is concluded that the accuracy of the surface shape of the grinding disc will decrease slightly with the increase of the rotating speed, but different from the expected result, the experiment proves that the grinding disc can still guarantee the high surface shape precision when the grinding disc is processed at high speed. It is shown that different rotation speeds can be selected according to different processing stages in the machining process, and on the one hand, the accuracy of the surface shape required for different processing stages can be guaranteed, and the processing efficiency can be improved on the other hand. This provides data support for the development of more intelligent processing strategies, which is beneficial to further digging the potential of the active grinding disc.
【学位授予单位】：中国科学院研究生院（光电技术研究所）
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TG58;TG806
【参考文献】
相关期刊论文 前10条
1 王琳,商周,王学伟;数据采集系统的发展与应用[J];电测与仪表;2004年08期
2 张伟,韩一明,吴新玲;基于FPGA的高速数据采集系统的设计[J];电力情报;2002年03期
3 扈啸,张s，
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