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浏览/检索结果: 共2条，第1-2条 帮助 限定条件 内容类型：会议论文    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 Geocentric distance's errors' correction of space cameras based on USGS DEM (EI CONFERENCE) 会议论文 2011 IEEE 3rd International Conference on Communication Software and Networks, ICCSN 2011, May 27, 2011 - May 29, 2011, Xi'an, China Yan D.; Xu S.; Li W. 收藏  |  浏览/下载：15/0  |  提交时间：2013/03/25 In order to correct the geocentric distance's error of TDI (Time Delay and Integration) CCD space camera in calculation of image motion compensation  the data source of the earth's height above sea level USGS DEM (United States Geological Survey Digital Elevation Model) has been introduced to make digital elevation map  the match error of the forward direction (the integral direction of TDI CCD) has been greatly decreased by correcting the geocentric distance error  and eliminate the influence to the relative error of image motion velocity  and correct the error generated by the different heights above sea level. After correcting  which greatly improves the imaging quality of TDI CCD space camera. 2011 IEEE.  a model of image motion calculation of nadir has been introduced  the calculation and analysis of the model shows that: the maximum error of image motion velocity about 1.72% has been decreased to 0.06%  and the influence of the geocentric distance error to the relative error of image motion velocity has been analyzed with the model   United steering of control moment gyros for small satellite with limited gimbal rate (EI CONFERENCE) 会议论文 2010 IEEE International Conference on Information and Automation, ICIA 2010, June 20, 2010 - June 23, 2010, Harbin, Heilongjiang, China Xu K.; Jin G.; Chen C. 收藏  |  浏览/下载：16/0  |  提交时间：2013/03/25 Single Gimbal Control Moment Gyroscopes (SGCMG) can could provide large control torque and quick attitude maneuver rate to small satellites without any increase in power  volume and mass  which will help small satellites become more powerful. Singularity avoidance and failure steering are two important problems to SGCMGs and also the main focus in this field. A new united steering law for SGCMGs with capabilities of singularity avoidance and quick transition of singularity surfaces is developed in this paper. To ensuring the existence of null motion  the commanded output of controller was changed real-timely as the variation of singularity measurement of SGCMGs  which can avoid the gimbal angle rate saturation. This developed steering law could help the SGCMGs provide real-time control toques in spite of limitation of gimbal angle rate. Simulation analysis is conducted for a certain 4-SGCMG system mounted on a small satellite. Simulation results indicate that the steering law is very effective in singularity avoidance. 2010 IEEE.