中国科学院机构知识库网格系统: 检索

Analysis on the influence of random vibration on MEMS gyro precision and error compensation (EI CONFERENCE) 会议论文 OAI收割
2011 3rd International Conference on Mechanical and Electronics Engineering, ICMEE 2011, September 23, 2011 - September 25, 2011, Hefei, China
作者: Li M.

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In order to improve its precision in dynamic environment a Kalman filter was designed. Firstly two sets of random drift data of MEMS gyro were respectively analysed and it was found that the variance of random drift under random vibration significantly increased and its mean also changed. Then calculation results show that attitude angle error under random vibration is 2.6 while in the static test it is 0.25. Analysis on the characteristics of random drift was carried out and it is found that it can be treated as stable normally distributed random signal. Finally a corresponding Kalman filter was designed. The results indicated that after filtering the variance of random drift is reduced to 0.0282 26.4% of pre-filtering and the attitude angle error is reduced to 1.5 57.7% of pre-filtering. The above method can effectively compensate for the attitude angle error of MEMS gyro caused by random vibration. This study can be a reference to the application of low-cost MEMS gyro in aircraft navigation. (2012) Trans Tech Publications Switzerland.

Restricted H.264/AVC video coding for privacy protected video scrambling 期刊论文 OAI收割
JOURNAL OF VISUAL COMMUNICATION AND IMAGE REPRESENTATION, 2011, 卷号: 22, 期号: 6, 页码: 479-490
作者: Dai, Feng; Tong, Lingling; Zhang, Yongdong; Li, Jintao

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收藏 | 浏览/下载：22/0 | 提交时间：2019/12/16

Coding efficiency Drift error H.264/AVC Privacy protection Restricted video coding Security Video surveillance Video scrambling

Three-sample rotation vector algorithm with angular rate input (EI CONFERENCE) 会议论文 OAI收割
2011 2nd International Conference on Mechanic Automation and Control Engineering, MACE 2011, July 15, 2011 - July 17, 2011, Inner Mongolia, China
作者: Zhang Y.

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In order to research the attitude algorithm with angular rate input under the conical motion a optimal threesample rotation vector algorithm based on single-step Newton backward interpolation is proposed. Using the principle of limited rigid body rotation and the characteristic of angular rate input three-sample rotation vector algorithm is derivated. To minimum attitude errors three-sample rotation vector algorithm is optimized. Three angular rate extraction methods of singlestep entire sample recursion multi-step entire sample and singlestep Newton backward interpolation are proposed. Under the condition of conical motion with semi-cone angle 3 and angular frequency 2rad/s simulation is done. The simulation results show that single-step Newton backward interpolation is superior to the other two methods and its maximum error peak is 0.01 error drift rate is 0.036/h. Experiments in three-axis flying turntable with the same parameters are carried out and the results show that error drift rates of three-channels are less than those of traditional quaternion which are 13.53% 12.08% and 23.68% lower respectively. It also verified that the new algorithm can perform a high accuracy under the conical motion. 2011 IEEE.

Research on the identification for a nonlinear system (EI CONFERENCE) 会议论文 OAI收割
International Conference on Optical, Electronic Materials and Applications 2011, OEMA 2011, March 4, 2011 - March 6, 2011, Chongqing, China
作者: Liu J.; Jia P.; Liu J.; Liu J.

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The characteristic of the drift error of inertial platform is a high-order nonlinear dynamic system using the neural networks' abilities of universal approximation of differentiable trajectory and capturing system dynamic information this paper presents the drift error identifying project of inertial platform based on Elman networks structure. First the drift error model of inertial platform is established after selecting the input and output for network momentum and alterable speed algorithm is used to speed up the network convergence. On the basis of the algorithm the extended nonlinear node function in the hidden network does not only improve the learning speed of network but also satisfies the need of accuracy on system identification. Through the drift error data measured on inertial platform the training result shows that the scheme achieves satisfied identification results. (2011) Trans Tech Publications.

Control strategies and error compensation methods of high precision gyro stabilized platform (EI CONFERENCE) 会议论文 OAI收割
30th Chinese Control Conference, CCC 2011, July 22, 2011 - July 24, 2011, Yantai, China
Deng K.; Cong S.; Shen H.

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Based on the principle of gyroscope and the structure of gyro stabilized platform this paper gives the analysis and comparison of control strategies for stable platform included classical PID control and three kinds of advanced strategies: Fuzzy Control Sliding Mode Variable Structure Control and Active Disturbance Rejection Control. The compensation methods for stable platform's error are also discussed and evaluated based on the sources of error especially for the non-linear friction and gyro drift. The paper provides the reliable methods for recognizing and improving the accuracy of gyro stabilized platform from the control strategies and error compensations. 2011 Chinese Assoc of Automation.

High precision test method for dynamic imaging of space camera (EI CONFERENCE) 会议论文 OAI收割
2010 IEEE International Conference on Advanced Computer Control, ICACC 2010, March 27, 2010 - March 29, 2010, 445 Hoes Lane - P.O.Box 1331, Piscataway, NJ 08855-1331, United States
作者: Jin L.-X.; Zhang K.; Zhang K.; Zhang K.; Zhang K.

收藏 | 浏览/下载：24/0 | 提交时间：2013/03/25

A test method for dynamic imaging of space TDICCD (Time Delay and Integration Charge Coupled Devices) camera was presented in this paper. The test method adopted the PLL (Phase Locked Loop) technology and CMAC (Cerebella Model Articulation Controller) friction compensation as control strategy. Furthermore According to this method a test system for dynamic imaging of space TDICCD camera was designed and implemented. The system simulated the movement of the ground objects relative to the space aerocraft to validate the capability of image speed match and the dynamic imaging quality of TDICCD camera. The design adopted a precision turntable and a drift turntable to simulate the movement around the earth and the drift motion in different latitude due to the rotation of earth of the aerocraft. The turntables were drived by permanent magnet torque motor which was powered by PWM (Pulse Width Modulation). The system adopted DSP (Digital Signal Processor) as the control core and reached a very high performance. The experimental results showed that the steady speed error was better than 0.01 % and the instantaneous speed error reached 0.0267%. The precision of the test system designed met the requirement for dynamic imaging of TDICCD camera. 2010 IEEE.

Autocollimation form dual-frequency laser diffraction grating interferometer design and analysis (EI CONFERENCE) 会议论文 OAI收割
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China
Wang C.-G.

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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

Random noise filtering technology of piezoelectricity gyro (EI CONFERENCE) 会议论文 OAI收割
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China
Qingjun L.; Yongming Y.

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Inertia sensing elements are usually adopted as the sensors of velocity stabilization loop in airborne photoelectric equipments therefore we need to adopt filtering processing to reduce influence to control system. In this paper which are constituted stabilized control system we analyze the characteristic of noise gyro drift that purpose is reducing the influence of the movement of carrier to visual axis of photoelectric probing system. But gyro and utilize Kalman filtering technology to conduct filtering processing to output signal of gyro especially the piezoelectricity gyro generates drift this method can reduce output noise effectively. The simulation results show that the proposed filtering processing method can improve the low velocity characteristic. 2010 IEEE. which is the main error source of photoelectric stabilized control system

Fgs coding using cycle-based leaky prediction through multiple leaky factors 期刊论文 iSwitch采集
Ieee transactions on circuits and systems for video technology, 2008, 卷号: 18, 期号: 9, 页码: 1201-1211
作者: Ji, Xiangyang; Zheng, Yanyan; Zhao, Debin; Wu, Feng; Gao, Wen

收藏 | 浏览/下载：35/0 | 提交时间：2019/05/10

Drift error Fine granularity scalability (fgs) Leaky prediction Video coding

FGS Coding Using Cycle-Based Leaky Prediction Through Multiple Leaky Factors 期刊论文 OAI收割
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY, 2008, 卷号: 18, 期号: 9, 页码: 1201-1211
作者: Ji, Xiangyang; Zheng, Yanyan; Zhao, Debin; Wu, Feng; Gao, Wen

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收藏 | 浏览/下载：25/0 | 提交时间：2019/12/16

Drift error fine granularity scalability (FGS) leaky prediction video coding