QQ客服 官方微博 反馈留言

浏览/检索结果: 共5条，第1-5条 帮助 限定条件 专题：长春光学精密机械与物理研究所    第一署名单位    第一作者单位    通讯作者单位     已选(0)清除 条数/页：5101520253035404550556065707580859095100   排序方式：请选择作者升序作者降序题名升序题名降序发表日期升序发表日期降序提交时间升序提交时间降序 The research on adaptive measurement of angular acceleration for photoelectric servo turntable (EI CONFERENCE) 会议论文 2011 International Conference on Mechatronic Science, Electric Engineering and Computer, MEC 2011, August 19, 2011 - August 22, 2011, Jilin, China Liang W.; Guo J.; Chen J.; Feng F. 收藏  |  浏览/下载：18/0  |  提交时间：2013/03/25 The paper proposes a new measurement method of angular acceleration for photoelectric servo turntable. Piezoelectric angular acceleration sensor is used to measure angular acceleration directly  Adaptive FIR filter based on LMS algorithm is established on DSP  by which angular acceleration signal can be filtered and corrected errors adaptively  then angular acceleration signals can be measured adaptively. This method avoids measurement errors and calculation noise by computing angular acceleration indirectly  thus improving measurement precision and making measurement results better than traditional methods. The gotten angular acceleration can be sent to servo control mechanism as feed forward control signals to improve control effects of servo turntable significantly. 2011 IEEE.   Autocollimation form dual-frequency laser diffraction grating interferometer design and analysis (EI CONFERENCE) 会议论文 2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China Wang C.-G. 收藏  |  浏览/下载：19/0  |  提交时间：2013/03/25 Propose a new measurement system of autocollimation form laser grating heterodyne interferometer. Take grating diffraction and polarization optics as theoretical foundation  second  furthermore  combined with electronics knowledge to analyze the system. First  make use of autocollimation diffraction of grating  measurement information obtained by dual-frequency laser belongs to ac signal  the interferometer measurement system take grating pitch as measuring datum  the structure is simple  possess great gain and high signal-noise ratio  therefore  stable  completely overcome the disadvantages of DC level drift caused by light intensity variation of single-frequency laser  system can achieve nanometer resolution. 2010 IEEE.  reduce the impact of environmental factors  easy to install and debug  measurement error is small   Speech signal enhancement through wavelet domain MMSE filtering (EI CONFERENCE) 会议论文 2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China Fenghua Z.; Le Y.; Jian W.; Qiang S. 收藏  |  浏览/下载：17/0  |  提交时间：2013/03/25 A new speech enhancement system that combine robust signal enhancement and minimum signal distortion is proposed in this paper. The proposed method introduces frequency depended  parametric  MMSE filtering techniques that involve wavelet packets. Voice activity detection (VAD) is used to further distinguish speech from noise and help to adaptively remove noise components from color noise eruptive noisy speech  while perceptual criteria is also taken into account. Experimental results and objective quality measurement test results validate the proposed speech enhancement system and illustrate the benefit of the proposed wavelet domain MMSE filtering as an excellent speech enhancement method to provide sufficient noise reduction and good intelligibility and perceptual quality  without causing considerable signal distortion and musical background noise method. 2010 IEEE.   The design of acquisition circuit for grating digital signal based on FPGA (EI CONFERENCE) 会议论文 2010 3rd International Conference on Advanced Computer Theory and Engineering, ICACTE 2010, August 20, 2010 - August 22, 2010, Chengdu, China Jiang L.-F.; Wang W.-G. 收藏  |  浏览/下载：29/0  |  提交时间：2013/03/25 In order to resolve the poor suppression capability of noise and fitter interference existing in grating encoder high-rate subdivision and the poor accuracy of kam-to  counting circuit  the results show that the design method will help improve the controlled object of measurement precision and control accuracy. 2010 IEEE.  we design a circuit based on FPGA to realize multiplier  kam and filter for the output of two-way orthogonal signal generated by Incremental Optical Encoder. The system is mainly divided into three modules such as filtering  multiplier kam-to and counting. The main function of filter circuit is to eliminate the jitter and noise interference existing in the quadrate encoder signals. Kam-to multiplier circuit can accurately judge the full cycle and half-cycle of incremental encoder  at the same time can make fourfold multiplier. Counting circuit can use IP cores owned by Quartus II which is not restricted on the median. At last  timing simulation based on Modelsim carried on the three modules   UV-VUV spectral irradiance responsivity calibration for space remote sensing spectroradiometer (EI CONFERENCE) 会议论文 Advanced Materials and Devices for Sensing and Imaging III, November 12, 2007 - November 14, 2007, Beijing, China Yu H.; Shurong W.; Guanyu L.; Longqi W. 收藏  |  浏览/下载：14/0  |  提交时间：2013/03/25 In order to overcome the irradiance responsivity calibration troubles caused by the weak response of most spectral radiometers in ultraviolet band and poor ratio of signal to noise  and to meet special calibration condition for some remote sensing spectroradiometers in space  a spectral irradiance responsivity calibration unit based on parallel light illumination mode is established  it is composed of a 150W deuterium lamp and a spherical mirror. The calibration unit gets the output standard value of spectral irradiance by irradiance transfer  this way avoids the spectral reflectance measurement difficulty of the spherical mirror. A flight spectral radiometer model used for space remote sense was calibrated in range from 160nm to 300nm  the calibration error of spectral irradiance responsivity is 4.7%. Some factors which contribute to calibration uncertainties are discussed.