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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 Analyse the angular velocity estimation errors of -- filter based on high sampling rate (EI CONFERENCE) 会议论文 2011 2nd International Conference on Mechanic Automation and Control Engineering, MACE 2011, July 15, 2011 - July 17, 2011, Inner Mongolia, China Zhang Y.; Chu H. 收藏  |  浏览/下载：20/0  |  提交时间：2013/03/25 In order to get angular velocity of stabilization servo mechanism from angular position sensors  -- filter based on high sampling rate was established  model and error characteristics were analyzed. With the hypothesis of constant acceleration  -- filter and its angular velocity transfer function were deduced. Combing with optimum parameters  the effects of and sample rate on the error characteristics were evaluated. According to the requirements of stabilization servo mechanism  the frequency characteristics of angular velocity transfer function are analyzed  and the filter parameters are designed. The experimental which filter tracked and smoothed sinusoidal signal  the results show that when the cutoff frequency of angular velocity loop is 44.9rad/s  sampling period and parameters are 0.08ms and 0.01279 respectively  the phase leading of angular position is 70. -- filter tracked sinusoidal signals with maximum angular velocity(30/s) and maximum angular acceleration(30/s2)  the error of angular velocity estimation was 0.053/s. In the engineering of electro-optical stabilization servo mechanism  -- filter can reduce noise effectively  and reached the requirement of platform angular velocity estimation. Also it is one of the effective methods to get angular velocity from angular position sensors. 2011 IEEE.   The angular velocity estimation principal of -- filter based on high sampling rate (EI CONFERENCE) 会议论文 2011 2nd International Conference on Mechanic Automation and Control Engineering, MACE 2011, July 15, 2011 - July 17, 2011, Inner Mongolia, China Zhang Y.; Chu H. 收藏  |  浏览/下载：17/0  |  提交时间：2013/03/25 In order to get angular velocity of stabilization servo mechanism from angular position sensors  -- filter and its angular velocity transfer function were predigested. Combing with optimum parameters  -- filter based on high sampling rate was established  the effect of and sample rate on filter nature frequency were evaluated. According to the requirements of stabilization platform  the principle of steady and transient tracking filter differential were proved. With the hypothesis of constant acceleration  the frequency characteristics of angular velocity transfer function were analyzed  three-dimensional Kalman filter was simplified  and the filter parameters were designed. The results show that when the spectrum of input signal was lower than 6rad/s  parameters was 0.02  and sampling period were 0.08ms and 0.1ms respectively  the filter can realize differential exactly  when the spectrum was 9rad/s  the precision was no less than 1.1%  the phase leading of angular position was no less than 70  the natural frequency should be higher than the cut-off frequency of stabilization platform was two or three times. In the engineering of electro-optical stabilization servo mechanism  -- filter has properties of tracking differential  and reached the requirement of platform angular velocity estimation. Also it is one of the effective methods to get angular velocity from angular position sensors. 2011 IEEE.   Estimation algorithm of mobile OFDM CFOs based on step-size (EI CONFERENCE) 会议论文 2009 International Conference on Information Engineering and Computer Science, ICIECS 2009, December 19, 2009 - December 20, 2009, Wuhan, China Lin L.; Qiao Y.-F.; Su W.-X. 收藏  |  浏览/下载：20/0  |  提交时间：2013/03/25 In order to maintain orthogonality among subcarriers for mobile OFDM  a CFOs step-size estimation model is established to avoid severe performance degradation caused by ICI  and algorithmic stability  step-size parameter  the error of CFOs estimate and etc are investigated. First  after an averaging window algorithm is introduced  the mathematic model of step-size estimation algorithm is obtained through step-size parameter and time-varying CFOs. Then  based on the results of MATLAB simulation  the determination of step-size parameter  the advantages of step-size algorithm and precision are discussed. Finally  time sequence plots of added CP  interleaver and subcarrier modulation with VHDL are presented. Experimental results indicate that the maximum of CFOs errors is 0.00987 in 3 variance interval  when mobile velocity is 400 km/h  according with verdicted principle that in order for the ICI effects to be negligible  the error of CFOs estimation must be accurate within 1-2% of the subcarrier spacing  and programs can correctly implement on circuit board. 2009 IEEE.   The analysis and design of low velocity estimation based on observer (EI CONFERENCE) 会议论文 2009 IEEE International Conference on Automation and Logistics, ICAL 2009, August 5, 2009 - August 7, 2009, Shenyang, China Song Y.; Gao H.; Zhang S.; Tian Y.; Wang D. 收藏  |  浏览/下载：23/0  |  提交时间：2013/03/25 Low velocity servo system needs precision velocity estimation. An observer for low velocity estimation was proposed in this paper. First  the source of low velocity estimation errors and the shortcomings of the single period difference were analyzed. The relationship between the estimation accuracy and estimator's frequency characteristics was concluded. Then  the structure of the observer was proposed. Frequency characteristics were used to design the compensator which can stabilize the observer. The stability of the observer was also discussed. At last  the observer's estimation accuracy was evaluated through a quantitative comparison. The results of simulation and experiment have shown that the quantized error in velocity estimation decreases dramatically when a velocity observer is used. Compared with some commonly-used estimators  the phase lag accompanying the observer is much less. 2009 IEEE.   Application of CMOS APS star tracker with large FOV in attitude and angular velocity determination (EI CONFERENCE) 会议论文 Advanced Sensor Systems and Applications III, November 12, 2007 - November 14, 2007, Beijing, China Lu D.; Guang J.; Shaoju W.; Tao C. 收藏  |  浏览/下载：20/0  |  提交时间：2013/03/25 The paper deals with the spacecraft attitude determination problem using a new kind of star tracker with large FOV based on CMOS APS. Star tracker has been developed since 1970s and proved to be the most accurate sensor ever used in the spacecraft attitude determination systems. But the traditional CCD star tracker also has some disadvantages  such as small FOV  high power consumption  low sample rate and low working angular rate limit which prevent the use of CCD star tracker in attitude large angle maneuvering process. The new kind of star tracker based on CMOS APS has no such disadvantages and is more applicable on modern low-cost agile small satellites. Its higher sample rate and working angular rate limit over traditional CCD star tracker make it more adapt for spacecraft angular velocity determination. Because of the large FOV of the star tracker  the mathematical model of traditional CCD star tracker with a small FOV is not appropriate. So a new mathematical model was quoted to fit the star tracker with a large FOV. An alternative adaptive algorithm was also introduced in the paper. It can help the EKF algorithm work lacking of accurate covariance of the observation noise. An optimal estimation algorithm was used to estimate the angular velocity directly from the star tracker measurements. Mathematic simulation results indicate the CMOS APS star tracker can give accurate attitude information and estimated angular rate. The method can be used as the chief attitude determination system design of low-cost satellite without gyros  or be used as a backup strategy in the event of gyro failures to enhance the reliability of the attitude determination system.