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浏览/检索结果: 共2条，第1-2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 Design of motion adjusting system for space camera based on ultrasonic motor (EI CONFERENCE) 会议论文 International Symposium on Photoelectronic Detection and Imaging 2011: Space Exploration Technologies and Applications, May 24, 2011 - May 26, 2011, Beijing, China Xu K.; Jin G.; Gu S.; Yan Y.; Sun Z. 收藏  |  浏览/下载：74/0  |  提交时间：2013/03/25 Drift angle is a transverse intersection angle of vector of image motion of the space camera. Adjusting the angle could reduce the influence on image quality. Ultrasonic motor (USM) is a new type of actuator using ultrasonic wave stimulated by piezoelectric ceramics. They have many advantages in comparison with conventional electromagnetic motors. In this paper  some improvement was designed for control system of drift adjusting mechanism. Based on ultrasonic motor T-60 was designed the drift adjusting system  which is composed of the drift adjusting mechanical frame  the ultrasonic motor  the driver of Ultrasonic Motor  the photoelectric encoder and the drift adjusting controller. The TMS320F28335 DSP was adopted as the calculation and control processor  photoelectric encoder was used as sensor of position closed loop system and the voltage driving circuit designed as generator of ultrasonic wave. It was built the mathematic model of drive circuit of the ultrasonic motor T-60 using matlab modules. In order to verify the validity of the drift adjusting system  was introduced the source of the disturbance  and made simulation analysis. It designed the control systems of motor drive for drift adjusting system with the improved PID control. The drift angle adjusting system has such advantages as the small space  simple configuration  high position control precision  fine repeatability  self locking property and low powers. It showed that the system could accomplish the mission of drift angle adjusting excellent. 2011 SPIE.   Low drive-voltage and high-bandwidth electro-optic modulators based on BaTiO3 thin-film waveguides (EI CONFERENCE) 会议论文 Science and Technology of Dielectrics for Active and Passive Photonic Devices - 210th Electrochemical Society Meeting, October 29, 2006 - November 3, 2006, Cancun, Mexico Sun D. G.; Fu X. H.; Liu Z. F.; Ho S. T.; Wessels B. W. 收藏  |  浏览/下载：32/0  |  提交时间：2013/03/25 We investigated electro-optic modulator structures to target low drive voltage  high-speed modulation  and small device size with c-axis grown BaTiO3/MgO ferro-electric thin films. In this study  the calculations are focused on the ideal thin film with a quadratic relation between the half-wave drive voltage V and the interaction length L in the electro-optic modulation case we obtained in previous work. With the quadratic electro-optic modulating relation and the optimal rib waveguide structure of BaTiO3/MgO thin films  the frequency-voltage-size performances for 2.5GHz  10GHz  40GHz  and 100GHz modulation bandwidths have been obtained under half-wave drive voltages of 0.8V  1.6V  3.0V and 4.8V  respectively  for the ideal film with r51=730 pm/V at 1550nm wavelength  where both the phase velocity matching condition and the conductor induced microwave attenuation are considered. The required device lengths to achieve these four typical values of modulation bandwidth are 3.3 mm  0.8 mm  0.4 mm and 0.2 mm  respectively. With the c-axis grown BaTiO3/MgO crystal thin films and the quadratic electro-optic modulating relation  an electro-optic coefficient of reff=180 pm/V for the c-axis grown BaTiO3/MgO ferro-electric thin films was measured  which is relatively far from the ideal value of r51=560 pm/V. copyright The Electrochemical Society.