中国科学院机构知识库网格系统: 检索

eloran系统新型信号波形设计及其性能评估 期刊论文 OAI收割
全球定位系统, 2020, 卷号: 45, 期号: 2, 页码: 13
作者: 李婉清; 刘中伟; 李实锋; 叶清琳

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advanced Loran navigation system new signal system waveform design performance assessment spectrum analysis 增强罗兰导航系统信号体制波形设计性能评估频谱分析

Modeling and variable structure control of a vehicle flexible manipulator (EI CONFERENCE) 会议论文 OAI收割
10th World Congress on Intelligent Control and Automation, WCICA 2012, July 6, 2012 - July 8, 2012, Beijing, China
作者: Wang Z.; Li Y.; Li Y.; Li Y.; Li Y.

收藏 | 浏览/下载：23/0 | 提交时间：2013/03/25

In this paper the mathematical modeling and the application of a new trajectory tracking control technique for hydraulic-driven rigid-flexible manipulator are concerned. To get a closer dynamic behavior of the real system both the flexible manipulator linkage and the actuator dynamics are considered. The exact dynamic model of flexible manipulator is derived using Lagrange principle and assumed modes method. The partial decoupled dynamic equation is derived using nonlinear decoupling feedback control method. The whole dynamic model is established by a driven Jacobin matrix which represents the coupling between hydraulic servo system and mechanical system. A variable structure controller with inverse dynamics is designed for trajectory tracking. To weaken the chattering of control signal saturation function is used to instead of sign function. The experimental results investigate the effectiveness of the proposed approaches. 2012 IEEE.

Design of control system of DC motor based on fusion FPGA (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Mechatronics and Materials Processing, ICMMP 2011, November 18, 2011 - November 20, 2011, Guangzhou, China
Zhu D. D.; Li H. W.

收藏 | 浏览/下载：34/0 | 提交时间：2013/03/25

Along with the development of microelectronic process it is possible to integrate a big system in one chip. A new way to implement system on a chip is provided by the advent of FPGA. Based on Verilog HDL and the Actel Fusion AFS600 FPGA chip the speed closed-loop control system of DC motor was designed by using options of combining the top-down thinking and the bottom-up method. PID control algorithm encoder signal processing and PWM waveform generation etc were realized by the system. The results show that the system structure is simplified and the stability and reliability are improved. A solution of system on a chip is realized to some extent. It has extensive application value in engineering practice. 2011 Trans Tech Publications.

Evaluation of the operating range for ground-based infrared imaging tracking system (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, May 24, 2011 - May 24, 2011, Beijing, China
作者: Zhang Z.-D.

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Ground-based infrared imaging tracking system (GIITS) is of great importance for aerial target warning and guard. The operating range is one of the key performance specifications on the other which should be calculated calculate the radiation power received on the detector in order to analysis whether the output signal meets the detection requirements or not analyzed and studied during the whole GIITS design process. The operating range is mostly influenced by a few factors without considering the effect of the background radiation. By improving of the traditional method including atmospheric attenuation a new operating range calculation model of the GIITS was established based on two requirements. One is that the image size of observed target should meet the requirement of the processor signal extraction. The number of the pixel occupied by target image should be more than 9. The other is that the signal noise ratio (SNR) of the GIITS should not be less than 5 to meet the requirements of the target detection probability and spatial frequency. The SNR calculation equation in form of energy is deduced and the radiation characteristic of the observed target and background are analyzed. When evaluate the operating range of the GIITS using the new method the performance of GIITS and feature of target and background. This paper firstly makes analysis and summarization on the definite localizations of the traditional operating range equation of the GIITS. The localizations are mainly in two aspects. On one hand we should successively calculate two operating range values according to two requirements mentioned above and choose the minimum value as the analytic result. In the end the dispersion of the image and the effect of image dispersion are not considered in the traditional method an evaluation of operating range for fighter aircraft is accomplished as an example. The influence factors in every aspect on operating range were explored by the calculated result. The new operating range calculation model provides the theoretical basis for the design and applications as well as the comprehensive evaluation of a GIITS. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

Technology of USB HOST applying in traffic controller based on ISP1161A (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Electronic and Mechanical Engineering and Information Technology, EMEIT 2011, August 12, 2011 - August 14, 2011, Harbin, China
Haibo L.; Song K.

收藏 | 浏览/下载：20/0 | 提交时间：2013/03/25

Control and management of the urban traffic signal is an problem that modern city has to face. The traffic signal controller makes a great contribution to the improvement of traffic status and the reduction of traffic jam. A traffic controller is designed using the technology of USB host based on ISP1161A. Universal serial bus is new interface bus architecture for PC which supports the PnP function Of PC peripheral equipments and has been widely used in computer and communicational devices. ISP1161A complies with the protocol of USB1.1 and is used as the core part of the system. As a new try the USB host technology is applied into the design of controller to implement the communication with PC. Configuration of scheme is carried out successfully. The USB host technology makes configuration of scheme and future update easier and more convenient. 2011 IEEE.

The research on servo control technology of O-E theodolite based on angular acceleration sensor (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
Wei L.; Jin G.; Juan C.

收藏 | 浏览/下载：23/0 | 提交时间：2013/03/25

A new servo control methods for O-E theodolite is presented in this paper. The methods integrates optimally feed forward and feedback control and adopts acceleration delay compensation based on velocity delay compensation then achieves servo control of O-E theodolite effectively. Furthermore Angular acceleration sensor is applied as information resources and adaptive filter is formed to provide with feed forward control signal in the methods. For double closed loop servo control system of O-E theodolite the location correction loop and velocity correction loop are analyzed and designed. Simulation and experimental results show that comparing with traditional methods this servo control methods can improve significantly tracking precision and stability of O-E theodolite. 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

Speech signal enhancement through wavelet domain MMSE filtering (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
Fenghua Z.; Le Y.; Jian W.; Qiang S.

收藏 | 浏览/下载：26/0 | 提交时间：2013/03/25

A new speech enhancement system that combine robust signal enhancement and minimum signal distortion is proposed in this paper. The proposed method introduces frequency depended parametric MMSE filtering techniques that involve wavelet packets. Voice activity detection (VAD) is used to further distinguish speech from noise and help to adaptively remove noise components from color noise eruptive noisy speech while perceptual criteria is also taken into account. Experimental results and objective quality measurement test results validate the proposed speech enhancement system and illustrate the benefit of the proposed wavelet domain MMSE filtering as an excellent speech enhancement method to provide sufficient noise reduction and good intelligibility and perceptual quality without causing considerable signal distortion and musical background noise method. 2010 IEEE.

Design and image restoration research of a cubic-phase-plate system (EI CONFERENCE) 会议论文 OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies, April 26, 2010 - April 29, 2010, Dalian, China
作者: Zhang J.; Zhang J.; Zhang J.; Shi G.; Zhang X.

收藏 | 浏览/下载：25/0 | 提交时间：2013/03/25

Wave-front coding technology is a novel jointly optical and digital imaging technology which can greatly extend the depth of focus of optical systems. The image restoration process is an important part of wave-front coding technology. Using wave-front coding makes the modulation transfer function(MTF) values of the optical systems change little over a range of several times the depth of focus which means the system MTF is quite insensitive to defocus and there is no zero in the passband. So we can design a single filter for the restoration of images in different defocus positions. However it's hard to avoid noise during image acquisition and transmission processes. These noises will be amplified in the image restoration especially in the high frequency part when the MTF drop is relatively low. The restoration process significantly reduces the system signal to noise ratio this way. Aimed at the problem of noise amplification a new algorithm was proposed which incorporated wavelet denoising into the iterative steps of Lucy-Richardson algorithm. Better restoration results were obtained through the new algorithm effectively solving the noise amplification problem of original LR algorithm. Two sets of identical triplet imaging systems were designed in one of which the cubic-phase-plate was added. Imaging experiments of the manufactured systems were carried and the images of a traditional system and a wave-front coded system before and after decoding were compared. The results show that the designed wave-front coded system can extend the depth of focus by 40 times compared with the traditional system while maintaining the light flux and the image plane resolution. 2010 Copyright SPIE - The International Society for Optical Engineering.

New phase measurement method for laser rangefinder (EI CONFERENCE) 会议论文 OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, April 26, 2010 - April 29, 2010, Dalian, China
作者: Meng Z.; Meng Z.

收藏 | 浏览/下载：27/0 | 提交时间：2013/03/25

A new phase measurement method is designed and presented by using the technique of signal shifting phase and the technique of signal multiplication for laser rangefinder. The intensity of laser light is modulated by cosine circuit signal at the same time the cosine circuit signal is thansformed sine signal by the shifting phase technique. Two signals mentioned above are multiplied by received signal from the target respectively then being transmitted into signal processor after passing through low band filter respectively. The result of phase-shift between the received signal and sent signal is calculated by means of signal processor and time-counter with double frequency of modulation signal. The proposed system is composed of four units such as control and count unit emitting and receiving unit of laser light signal processing unit and result display unit. The two most advantages of proposed system over others are its ability of proper isolation which reduces crosstalk and its independency thermal drift. Theoretical calculations and experimental results have shown the accuracy better than 2 mm. 2010 Copyright SPIE - The International Society for Optical Engineering.