中国开放科研知识云: 检索

Error analysis of the micro temperature control system (EI CONFERENCE) 会议论文
2012 International Conference on Measurement, Instrumentation and Automation, ICMIA 2012, September 15, 2012 - September 16, 2012, Guangzhou, China
Han Z.; Song K.

收藏 | 浏览/下载：44/0 | 提交时间：2013/03/25

In order to improve the measurement accuracy of optical detection instruments temperature control circuits for narrow band-pass filters are given and the error analysis is applied to temperature control circuits.The principle of a temperature measurement circuit is studied and the method of a driver circuit is described. A variety of influencing factors of temperature control accuracy are discussed. Moreover for these error factors improvement measures are given to reduce the nonlinear error. Finally circuit parameter error is quantified to propose a calculation method for margin of error in a temperature control system. (2013) Trans Tech Publications Switzerland.

Determination of optimum process parameters in gas-assisted injection molding (EI CONFERENCE) 会议论文
2011 International Conference on Electrical Information and Mechatronics, ICEIM2011, December 23, 2011 - December 25, 2011, Jiaozuo, China
Zi K.; Chen L.

收藏 | 浏览/下载：13/0 | 提交时间：2013/03/25

With finite element analysis software Moldflow numerical simulation and studies about FM truck roof handle were conducted on gas-assisted injection molding process. The influences of melt pre-injection shot gas pressure delay time and melt temperature were observed by using multi-factor orthogonal experimental method. According to the analysis of the factors' impact on evaluation index the optimized parameter combination is obtained. Therefore the optimization design of technological parameters is done. The results show that during the gas-assisted injection molding optimum pre-injection shot is 94% gas pressure is 15MPa delay time is 0.5s melt temperature is 240 C. This study provided a more practical approach for the gas-assisted injection molding process optimization.

Space camera dynamic image quality measurement and evaluation (EI CONFERENCE) 会议论文
3rd International Conference on Measuring Technology and Mechatronics Automation, ICMTMA 2011, January 6, 2011 - January 7, 2011, Shanghai, China
Su W.; Zhang X.

收藏 | 浏览/下载：15/0 | 提交时间：2013/03/25

By using analysis of the infinity image of the space camera we intend to obtain the curve of the dynamic modulation transfer function. We extract the pixel gray values at the image edge which distribute as a knife-edge function and make differential calculation and Fourier transformation of it and then we can obtain the dynamic MTF curve of the optical system. The value of the curve at the Nyquist frequency is the most important parameter that reflects the image quality. We add push-scanning imaging and environmental effects to the static MTF of space camera and compare the MTF value with the dynamic MTF at Nyquist frequency. The comparison result can help us verify the accuracy of the calculating results and the feasibility of our method. (2011) Trans Tech Publications.

The new approach for infrared target tracking based on the particle filter algorithm (EI CONFERENCE) 会议论文
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, May 24, 2011 - May 24, 2011, Beijing, China
Sun H.; Han H.-X.

收藏 | 浏览/下载：50/0 | 提交时间：2013/03/25

Target tracking on the complex background in the infrared image sequence is hot research field. It provides the important basis in some fields such as video monitoring precision and video compression human-computer interaction. As a typical algorithms in the target tracking framework based on filtering and data connection the particle filter with non-parameter estimation characteristic have ability to deal with nonlinear and non-Gaussian problems so it were widely used. There are various forms of density in the particle filter algorithm to make it valid when target occlusion occurred or recover tracking back from failure in track procedure but in order to capture the change of the state space it need a certain amount of particles to ensure samples is enough and this number will increase in accompany with dimension and increase exponentially this led to the increased amount of calculation is presented. In this paper particle filter algorithm and the Mean shift will be combined. Aiming at deficiencies of the classic mean shift Tracking algorithm easily trapped into local minima and Unable to get global optimal under the complex background. From these two perspectives that "adaptive multiple information fusion" and "with particle filter framework combining" we expand the classic Mean Shift tracking framework.Based on the previous perspective we proposed an improved Mean Shift infrared target tracking algorithm based on multiple information fusion. In the analysis of the infrared characteristics of target basis Algorithm firstly extracted target gray and edge character and Proposed to guide the above two characteristics by the moving of the target information thus we can get new sports guide grayscale characteristics and motion guide border feature. Then proposes a new adaptive fusion mechanism used these two new information adaptive to integrate into the Mean Shift tracking framework. Finally we designed a kind of automatic target model updating strategy to further improve tracking performance. Experimental results show that this algorithm can compensate shortcoming of the particle filter has too much computation and can effectively overcome the fault that mean shift is easy to fall into local extreme value instead of global maximum value.Last because of the gray and fusion target motion information this approach also inhibit interference from the background ultimately improve the stability and the real-time of the target track. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

Optimum design of the carbon fiber thin-walled baffle for the space-based camera (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
Yan Y.; Gu S.; An Y.; Jin G.

收藏 | 浏览/下载：11/0 | 提交时间：2013/03/25

The thin-walled baffle design of the space-based camera is an important job in the lightweight space camera research task for its stringent quality requirement and harsh mechanical environment especially for the thin-walled baffle of the carbon fiber design. In the paper an especially thin-walled baffle of the carbon fiber design process was described and it is sound significant during the other thin-walled baffle design of the space camera. The designer obtained the design margin of the thin-walled baffle that structural stiffness and strength can tolerated belong to its development requirements through the appropriate use of the finite element analysis of the walled parameters influence sensitivity to its structural stiffness and strength. And the designer can determine the better optimization criterion of thin-walled baffle during the geometric parameter optimization process in such guiding principle. It sounds significant during the optimum design of the thin-walled baffle of the space camera. For structural stiffness and strength of the carbon fibers structure which can been designed the effect of the optimization will be more remarkable though the optional design of the parameters chose. Combination of manufacture process and design requirements the paper completed the thin-walled baffle structure scheme selection and optimized the specific carbon fiber fabrication technology though the FEM optimization and the processing cost and process cycle are retrenchment/saved effectively in the method. Meanwhile the weight of the thin-walled baffle reduced significantly in meet the design requirements under the premise of the structure. The engineering prediction had been adopted and the related result shows that the thin-walled baffle satisfied the space-based camera engineering practical needs very well its quality reduced about 20% the final assessment index of the thin-walled baffle were superior to the overall design requirements significantly. The design method is reasonable and efficient to the other thin-walled baffle that mass and work environment requirement is requirement harsh. 2011 SPIE.

An autostereoscopic projecting system based on parallax barrier and lenticular sheets (EI CONFERENCE) 会议论文
2nd International Conference on Multimedia Technology, ICMT 2011, July 26, 2011 - July 28, 2011, Hangzhou, China
Kong L.; Jin G.; Zhong X.

收藏 | 浏览/下载：13/0 | 提交时间：2013/03/25

In order to realize autostereoscopic 3D projecting display with higher brightness and larger size a technique of autostereoscopic 3D projecting using parallax barriers and lenticular sheets is proposed.The parameter design of lenticular sheets and parallax barriers is investigated.First projection distance of projector array is confirmed according to eye's resolution then the strips' character of lenticular sheets is analysed by zemax in four-view situation thickness and parameters of strips of lenticular sheets are confirmed. Finally the width of slit and pitch and viewing distance and etc of parallax barriers are confirmed according to parameters of strips of lenticular sheets.Data analysis indicate that the brightness of our four-view image is increased three times because of using lenticular sheets instead of parallax barriers comparing with the autostereoscopic 3D projector using two parallax barriers plates.Parameters design of parallax barriers and lenticular sheets are finished the feasibility and advantages of the 3D display of projecting are confirmed theoretically. 2011 IEEE.

A local feature based simplification method for animated mesh sequence (EI CONFERENCE) 会议论文
2010 2nd International Conference on Computer Engineering and Technology, ICCET 2010, April 16, 2010 - April 18, 2010, Chengdu, China
Zhang S.; Zhao J.; Wang B.

收藏 | 浏览/下载：21/0 | 提交时间：2013/03/25

Although animated meshes are frequently used in numerous domains only few works have been proposed until now for simplifying such data. In this paper we propose a new method for generating progressive animated models based on local feature analysis and deformation area preservation. We propose the use of solid angle and height value for a non-hyperbolic vertex to define the local feature parameter. This local factor is embedded to the vertex quadric error matrix when calculating the edge collapse cost. In order to preserve the areas with large deformation we add deformation degree weight to the aggregated quadric errors when computing the unified edge contraction sequence. Finally a mesh optimization process is proposed to further reduce the geometric distortion for each frame. Our approach is fast easy to implement and as a result good quality dynamic approximations with well-preserved fine details can be generated at any given frame. 2010 IEEE.

New LED illumination optical engine for micro-projection display (EI CONFERENCE) 会议论文
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optoelectronic Materials and Devices for Detector, Imager, Display, and Energy Conversion Technology, April 26, 2010 - April 29, 2010, Dalian, China
Feng C.; Meng Z.; Sun W.

收藏 | 浏览/下载：13/0 | 提交时间：2013/03/25

A new optical engine consisting of LEDs rectangular CPC rectangular lens array and micro display chip DMD is designed by using of KOLA illumination algorithm for micro-projection display. Detail description and analysis of the rectangular CPC and rectangular lens array are provided. The influence due to the size of rectangular CPC and rectangular lens array is analysed for illuminance uniformity on the DMD chip and light energy efficiency of the optical engine system by software ZEMAX. Based on the analysis of parameter of rectangular lens array the size of rectangular lens array more decrease the illumination uniformity. Experimental results show that the proposed illumination light optical engine can obtain perfect rectangular focula with higher light uniformity more than 90 % and higher energy efficiency of 40 % to meet the needs of micro-projection display at the same time the designed illumination optical engine compared with other uniformizing light algorithm have advantages such as: lesser capacity high illumination uniformity. 2010 Copyright SPIE - The International Society for Optical Engineering.

Design and analysis of power system of micro-electromechanical actuator (EI CONFERENCE) 会议论文
2010 2nd International Conference on Industrial Mechatronics and Automation, ICIMA 2010, May 30, 2010 - May 31, 2010, Wuhan, China
Han X.; Liu B.; Zhang J.; Jia H.; Ge W.

收藏 | 浏览/下载：16/0 | 提交时间：2013/03/25

In order to apply the electromechanical actuator to tactical mini-missiles maximum rotational speed of output shafts is greater than 250/s. Test results basically correspond to the requirement of technical indexes. It is proved that this analysis and design method is congruent with the design of micro-electromechanical actuators this paper researches on the key technology such as load-bearing ability the system bandwidth can reach 25.3Hz on the condition of no load and 23.4Hz on the condition of load thus the method is feasible. 2010 IEEE. rapidity and miniaturization of the micro-electromechanical actuator power system based on the ball screw. First according to specific technical indexes the power electromechanical time constant and the size of the motors are screened originally through theoretical analysis. Finally based on the characteristics of ball screw transmission load locus of the micro-electromechanical actuator dynamic system is theoretically analyzed and the optimum speed ratio is determined through parameter optimization. The results of the double closed loop controlled test on the principle prototype show: the system can operate normally with 2.5N.m hinge moment

A high-accuracy parameter estimation algorithm for jointless Frequency-shift track circuit (EI CONFERENCE) 会议论文
ISECS International Colloquium on Computing, Communication, Control, and Management, CCCM 2008, August 3, 2008 - August 4, 2008, Guangzhou, China
Jin Y.; Zheng X.; Ding T.

收藏 | 浏览/下载：13/0 | 提交时间：2013/03/25

FSK (Frequency Shift keying) signal which has advantages of narrow-bandwidth strong anti-interference ability long transmission distance and so on is used in jointless Frequency-shift track circuit to send different kinds of control signals. However as FSK is non-linearly modulated parameter estimation with high accuracy is hard to realize. Based on the spectrum analysis complement with time-frequency distribution a highaccuracy FSK signal parameter estimation algorithm is put forward in this paper. According to the signal characteristics under-sampling and ZFFT are used to improve the accuracy of spectrum analysis and the base frequency resolution meets system requirement of 0.02Hz. Wigner-Ville distribution has an excellent time-frequency concentration while serious cross-term interference at the same time. Through the design of kernel function the cross-terms are almost suppressed and the upper/down side frequency resolution meets the system requirement of 0.2Hz. The effectivities of all the methods mentioned above have been proved by MATLAB simulation which pave a solid way for the development of high-accuracy FSK signal parameter estimation devices. 2008 IEEE.

在结果中检索

相关链接

CORC

联系我们