Precision grinding is a key process for realizing the use of large-aperture aspherical optical elements in laser nuclear fusion devices,large-aperture astronomical telescopes,and high-resolution space cameras.In this ...Precision grinding is a key process for realizing the use of large-aperture aspherical optical elements in laser nuclear fusion devices,large-aperture astronomical telescopes,and high-resolution space cameras.In this study,the arc envelope grinding process of large-aperture aspherical optics is investigated using a CM1500 precision grinding machine with a maximum machinable diameter ofΦ1500 mm.The form error of the aspherical workpiece induced by wheel setting errors is analytically modeled for both parallel and cross grinding.Results show that the form error is more sensitive to the wheel setting error along the feed direction than that along the lateral direction.It is a bilinear function of the feed-direction wheel setting error and the distance to the optical axis.Based on the error function above,a method to determine the wheel setting error is proposed.Subsequently,grinding tests are performed with the wheels aligned accurately.Using a newly proposed partial error compensation method with an appropriate compensation factor,a form error of 3.4μm peak-to-valley(PV)for aΦ400 mm elliptical K9 glass surface is achieved.展开更多
铁道客车轮对上的不平衡质量影响列车运行安全及速度的进一步提升,轮对安装前需要精确检测不平衡质量并进行动平衡处理。本文提出自适应小波消噪、MUSIC(Multiple Signal Classification)谱估计、相关分析法相结合的方法,实现铁道客车...铁道客车轮对上的不平衡质量影响列车运行安全及速度的进一步提升,轮对安装前需要精确检测不平衡质量并进行动平衡处理。本文提出自适应小波消噪、MUSIC(Multiple Signal Classification)谱估计、相关分析法相结合的方法,实现铁道客车轮对动平衡振动信号特征的提取。通过Labview软件与MATLAB混合编程实现软件开发,并搭建铁道客车轮对动平衡测试平台进行实验验证,实验验证结果表明,经过降噪和采样分辨率的控制,可以克服现场噪声及频率干扰问题,提取的信号幅值及相位具有较高的精度,可实现轮对上不平衡质量及位置的准确探测。展开更多
基金Fellowship of China National Postdoctoral Program for Innovative Talents(Grant No.BX20200268)Research Project of State Key Laboratory of Mechanical System and Vibration(Grant No.MSV202103)+1 种基金National Natural Science Foundation of China(Grant No.51720105016)Higher Education Discipline Innovation Project(Grant No.B12016).
文摘Precision grinding is a key process for realizing the use of large-aperture aspherical optical elements in laser nuclear fusion devices,large-aperture astronomical telescopes,and high-resolution space cameras.In this study,the arc envelope grinding process of large-aperture aspherical optics is investigated using a CM1500 precision grinding machine with a maximum machinable diameter ofΦ1500 mm.The form error of the aspherical workpiece induced by wheel setting errors is analytically modeled for both parallel and cross grinding.Results show that the form error is more sensitive to the wheel setting error along the feed direction than that along the lateral direction.It is a bilinear function of the feed-direction wheel setting error and the distance to the optical axis.Based on the error function above,a method to determine the wheel setting error is proposed.Subsequently,grinding tests are performed with the wheels aligned accurately.Using a newly proposed partial error compensation method with an appropriate compensation factor,a form error of 3.4μm peak-to-valley(PV)for aΦ400 mm elliptical K9 glass surface is achieved.
文摘铁道客车轮对上的不平衡质量影响列车运行安全及速度的进一步提升,轮对安装前需要精确检测不平衡质量并进行动平衡处理。本文提出自适应小波消噪、MUSIC(Multiple Signal Classification)谱估计、相关分析法相结合的方法,实现铁道客车轮对动平衡振动信号特征的提取。通过Labview软件与MATLAB混合编程实现软件开发,并搭建铁道客车轮对动平衡测试平台进行实验验证,实验验证结果表明,经过降噪和采样分辨率的控制,可以克服现场噪声及频率干扰问题,提取的信号幅值及相位具有较高的精度,可实现轮对上不平衡质量及位置的准确探测。
