中国科学院机构知识库网格系统: 检索

Applications of differential barometric altimeter in ground cellular communication positioning network 期刊论文 OAI收割
IET SCIENCE MEASUREMENT & TECHNOLOGY, 2020, 卷号: 14, 期号: 3, 页码: 322-331
作者: Hu, Zhengqun; Zhang, Lirong; Ji, Yuanfa

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收藏 | 浏览/下载：25/0 | 提交时间：2021/12/06

cellular radio height measurement measurement errors Global Positioning System altimeters barometers least squares approximations Kalman filters surface fitting spread spectrum communication compensation matrix algebra GPS signal message structure power spectrum spread spectrum ranging signal fitting parameters least-square solution calibration compensation system noise variance matrix measurement noise variance matrix multibase station correction height information correction calculation DBA system systematic performance differential barometric altimeter ground cellular communication positioning network measurement datum distribution altitude positioning error Global Positioning System differential barometric altimetry system systematic implementation level continuous altitude measurement precise altitude measurement DBA systematic implementation aspect two dimensional curved surface fitting function sensor measurement correction filtering effect Kalman filter measuring station multiBSs navigation fusion

Design and analysis of performance of FSO communication system based on partially coherent beams 期刊论文 OAI收割
OPTICS COMMUNICATIONS, 2020
作者: Wu, Yan; Mei, Haiping; Dai, Congming; Zhao, Fengmei; Wei, Heli

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收藏 | 浏览/下载：37/0 | 提交时间：2020/10/19

Free space optical communication Partially coherent beams Exponentiated Weibull turbulence Generalized pointing errors System performance parameters

Structural amelioration of 920 nm optically pumped semiconductor vertical external-cavity surface emitting laser (OPS-VECSEL) (EI CONFERENCE) 会议论文 OAI收割
2nd International Conference on Energy, Environment and Sustainable Development, EESD 2012, October 12, 2012 - October 14, 2012, Jilin, China
作者: Liu Y.; Liu Y.; Wang L.; Wang L.; Wang L.

收藏 | 浏览/下载：20/0 | 提交时间：2013/03/25

920 nm optically pumped semiconductor vertical external-cavity surface emitting laser (OPS-VECSEL) has an important application in laser display. We constructed and optimized a 920 nm OPS-VECSEL with active region of In0.09Ga0.91As quantum well (QW) system pumped by 808 nm laser diode module. By the finite element method self-consistent solutions of the semiconductor electronic and optical equations are realized to calculate the characteristics parameters of OPS-VECSEL. The performances of device especially the mode the threshold and the optical-optical translation efficiency were analyzed by dealing with different number of QWs (1 2 and 3) in one period QW depth barrier width the component and dimension of the non-absorption layer. We chose an improved structure of them. On this basis we ameliorated the number of QW periods and the simulation showed that in order to obtain high performance device the choice of the number of QW periods must be cautious. (2013) Trans Tech Publications Switzerland.

Trajectory tracking control of a quad-rotor UAV based on command filtered backstepping (EI CONFERENCE) 会议论文 OAI收割
2012 3rd International Conference on Intelligent Control and Information Processing, ICICIP 2012, July 15, 2012 - July 17, 2012, Dalian, China
Gong X.; Bai Y.; Peng C.; Zhao C.; Tian Y.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

A quad-rotor unmanned aerial vehicle is an under-actuated strong coupled nonlinear system with parameters uncertainty and unknown external aerodynamic disturbance. The trajectory tracking control system with a nested double-loops structure is designed in this paper according to the coupling characteristic between the attitude angles and translational position. A PD control algorithm is proposed in the translational outer-loop to export the desired attitude signals to the attitude inner-loop. An adaptive backstepping control algorithm is designed in the inner-loop with respect to the uncertain rotational inertia and un-modeled disturbance while in order to reduce the computational complexity the command filtered approach is introduced into the designing procedure. And finally the numerical simulation results are presented for the trajectory tracking stabilization of a Quad-rotor which demonstrates the excellent performance of the proposed control system and illustrate its robustness in face of disturbance and uncertain parameters. 2012 IEEE.

Optimum design of laser encoding and decoding on laser beam-riding guidance (EI CONFERENCE) 会议论文 OAI收割
2nd International Conference on Frontiers of Manufacturing and Design Science, ICFMD 2011, December 11, 2011 - December 13, 2011, Taichung, Taiwan
作者: Yang L.; Yang L.

收藏 | 浏览/下载：33/0 | 提交时间：2013/03/25

Operating principle of laser beam-riding guidance was set forth. Based on the principle of spatial frequency-encoding experimental results demonstrated that the receiver can receive correctly the encoded signal and can decode the signal an optimum laser encoding mode was designed measurement for the missdistance is feasible and all the performance parameters satisfy the demand. (2012) Trans Tech Publications which can transfer continuous laser into pulse laser that represents different position information. Then the mathematic model of deviation from target is built Switzerland. a modified encoding pattern was presented which is composed of two light paths crossed 90. Azimuth information of target is given in orthogonal coordinate system and deviation from target is linearity. As well as characteristic distribution of spatial laser field is analyzed. Corresponding decoding mode was presented by testing in 2 kilometers outdoor

The parameter optimization of missile actuator based on spatial RSSR linkage mechanism (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Electric Information and Control Engineering, ICEICE 2011, April 15, 2011 - April 17, 2011, Wuhan, China
Ge M.; Han X.; Jia H.

收藏 | 浏览/下载：16/0 | 提交时间：2013/03/25

Analyzed the forms of movement of missile actuator based on spatial RSSR linkage mechanism. To achieve synchronic output of each axis applied the multi-body dynamic application ADAMS to realize its parametric modeling and optimization finally got the appropriate parameters to satisfy the performance. Then researched the parameters affection to synchronic performance completed the initial design of the actuator transmission system. 2011 IEEE.

Linear auto disturbance rejection controller for vector-controlled PMSM drive system (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Transportation, Mechanical, and Electrical Engineering, TMEE 2011, December 16, 2011 - December 18, 2011, Changchun, China
作者: Zhang K.; Zhang K.; Zhang K.; Zhang K.

收藏 | 浏览/下载：36/0 | 提交时间：2013/03/25

A high-performance robust controller of permanent-magnet synchronous motor (PMSM) drive with cascade linear auto disturbance rejection controller (LADRC) is proposed. The robust controller combines the simplicity of linear controller and the merit of the auto disturbance rejection controller (ADRC). First a systematic mathematical model is derived according to the required specifications for the PMSM drive system. Then for the model this paper designs the controller that includes three first-order LADRCs. The controller does not rely on the accurate mathematical model of motor. The controller can estimate and compensate the disturbances that include load disturbance and systematic parameters changes by the linear extended state observer (LESO). Simulation results show that compared with conventional PI controller the proposed approach has strong robustness. In the same load disturbance the speed fluctuation of the LADRCs accounts for 30% of PI controller. 2011 IEEE.

Distribution of gyroscope accuracy parameters for E-O stabilization platform (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Electric Information and Control Engineering, ICEICE 2011, April 15, 2011 - April 17, 2011, Wuhan, China
作者: Zhang X.; Zhang X.; Zhang X.; Jiang H.

收藏 | 浏览/下载：28/0 | 提交时间：2013/03/25

E-O stabilization platform performance is partly decided by gyroscope precision so it is important to choose a gyroscope with proper accuracy for an E-O stabilization platform. Based on the method of using a gyroscope in practice gyroscope error model is established. With the gyroscope error model gyroscope accuracy parameters that is bias repeatability bias stability scale factor scale factor nonlinearity output noise and bandwidth are separately analyzed. According to the concretely required performance indices for an E-O platform means of distribution of gyroscope accuracy parameters is proposed. A MEMS gyroscope is tested to get the parameters. Bias stability of the gyroscope is 0.08 /s while the bandwidth is 60 Hz. Output noise both at zero input and at nonzero input is analyzed by means of PSD to get the result that nonzero output noise is higher than zero output noise. Frequency response result of the gyroscope is dealt by means of correlation analysis. With all the tested result and the method of distribution of gyroscope accuracy parameters it is clear that how the gyroscope errors works in an E-O servo system. The principle of distribution of gyroscope accuracy parameters is helpful for choosing appropriate gyroscope for an E-O platform. 2011 IEEE.

Study on the azimuth bearing scheme of a large Alt-azimuth telescope (EI CONFERENCE) 会议论文 OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Large Mirrors and Telescopes, April 26, 2010 - April 29, 2010, Dalian, China
作者: Wang H.; Dai S.; Zhang J.; Wang H.; Zhang J.

收藏 | 浏览/下载：40/0 | 提交时间：2013/03/25

The azimuth bearing schemes in typical large Alt-azimuth telescopes especially the 3.5-m APO telescope and the 4.1-m SOAR telescope were analyzed. A scheme of high-angular contacted thrust ball bearing integrated with a radial ball bearing was put forward. According to the Hertz contact theory the corresponding parameters were designed for engineering application. The static performance parameters within the range of 60 85 original contact angle were calculated. Compared with the traditional plane thrust ball bearing the results shows that the high-angular (80) contact thrust ball bearing has more benefits at bearing strength and rigidity for large telescope. The 1500mm diameter prototyping bearing shows good performance including the axial jitter is 0.009mm the radial jitter is 0.006mm the maximum starting torque without load is 30N·m and the load capacity is more than 30t which offers advanced technique path for the buildup of the high precision azimuth shafting and the whole telescope system. 2010 Copyright SPIE - The International Society for Optical Engineering.

Nonlinear control design for system with mechanical resonance based on two tracking-differentiators (EI CONFERENCE) 会议论文 OAI收割
2010 IEEE International Conference on Mechatronics and Automation, ICMA 2010, August 4, 2010 - August 7, 2010, Xi'an, China
作者: Li J.; Li Y.; Li Y.; Li Y.; Li Y.

收藏 | 浏览/下载：22/0 | 提交时间：2013/03/25

A nonlinear control strategy for controlling a motion system with mechanical resonance is presented in this paper. A mathematical model of the servo system is derived according to the parameters of an actual system. By using two Tracking-Differentiators reference input and system output are tracked and their differential signals are given simultaneously. A nonlinear PD control law in velocity loop is designed based on non-smooth feedback. The simulation results show that the control law is superior remarkably in performance to linear PD control law and the classical PID control law. Tracking-Differentiator resolves the contradiction between rapidity and overshoot of system response. The nonlinear PD control law improves system dynamic performance and intensifies the ability of disturbance rejection. The control design achieved in this paper makes the servo system more robust. 2010 IEEE.