中国科学院机构知识库网格系统: 检索

Migration of seismic multiple reflections 期刊论文 OAI收割
CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION, 2018, 卷号: 61, 期号: 3, 页码: 1025-1037
作者: Liu YiKe; Liu XueJian; Zhang YanBao

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收藏 | 浏览/下载：26/0 | 提交时间：2018/09/26

PID control of glucose concentration in subjects with type 1 diabetes based on a simplified model: An in silico trial (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: Yu L.

收藏 | 浏览/下载：34/0 | 提交时间：2013/03/25

An artificial pancreas system (APS) mimics the function of a real pancreas through monitoring a diabetic's blood glucose and administering the right dose of insulin via an automatic control loop. It is hailed as a promising cure of diabetes though this technology is still years away from commercial use due to a few technological bottlenecks. The simulation model of insulin-glucose metabolism of type 1 diabetes mellitus (T1DM) is an essential part of APS. In order to simplify the parameter identification task so that the model can be implemented electronically with ease this paper presents a simplified model based on Routh approximation model reduction method. The results show that the approximation error between the simplified model and the original model is so small that can be neglected. Based on the simplified model a PID controller is designed to maintain normoglycemia (90mg/dl) in subjects with T1DM. The in silico simulation results show that the glucose concentration is controlled well the risk of hyperglycemia and hypoglycemia is reduced a lot. This suggests that the simplified model describes the insulin-glucose metabolism process accurately and the PID control algorithm is well-suitable to guide the further development of an APS. 2012 IEEE.

The analyze and design of focusing system for space camera (EI CONFERENCE) 会议论文 OAI收割
2012 International Conference on Electrical Insulating Materials and Electrical Engineering, EIMEE 2012, May 25, 2012 - May 27, 2012, Shenyang, Liaoning, China
作者:

收藏 | 浏览/下载：32/0 | 提交时间：2013/03/25

In order to control the focal plane and guarantee the imaging quality of space camera the focusing system was proposed. Firstly the reasons of defocusing were analyzed and a solution method was given. Secondly the system structure and operating principle were introduced. Thirdly the system design was presented in detail. Finally the system was experimented. Experimental results indicate that the defocusing amount of camera can be controlled below 10 um and the focusing system satisfies the requirement of system design. (2012) Trans Tech Publications Switzerland.

The design of acquisition circuit for grating digital signal based on FPGA (EI CONFERENCE) 会议论文 OAI收割
2010 3rd International Conference on Advanced Computer Theory and Engineering, ICACTE 2010, August 20, 2010 - August 22, 2010, Chengdu, China
作者: Wang W.-G.

收藏 | 浏览/下载：43/0 | 提交时间：2013/03/25

In order to resolve the poor suppression capability of noise and fitter interference existing in grating encoder high-rate subdivision and the poor accuracy of kam-to counting circuit the results show that the design method will help improve the controlled object of measurement precision and control accuracy. 2010 IEEE. we design a circuit based on FPGA to realize multiplier kam and filter for the output of two-way orthogonal signal generated by Incremental Optical Encoder. The system is mainly divided into three modules such as filtering multiplier kam-to and counting. The main function of filter circuit is to eliminate the jitter and noise interference existing in the quadrate encoder signals. Kam-to multiplier circuit can accurately judge the full cycle and half-cycle of incremental encoder at the same time can make fourfold multiplier. Counting circuit can use IP cores owned by Quartus II which is not restricted on the median. At last timing simulation based on Modelsim carried on the three modules

A design on a control method of a new type of focal plane shutter (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
Xue L.; Ming L.; Zheng L.-N.; Zhou J.-F.; Zhang H.-W.; Zhang J.-C.

收藏 | 浏览/下载：36/0 | 提交时间：2013/03/25

In order to ensure appropriate exposure time and no exposure while electric charge is transferring after taking a photograph it is necessary to have the shutter mechanism cooperate with CCD for area CCD aerial cameras. The ground object illumination has a wide range which is from 4000Lx to 100000Lx so a shutter which is high efficient and a continuous stepless adjustment are also required. This paper introduces the fundamental principle structural design and control procedure about this new focal plane shutter. Under the control of DSP the velocity of shutter curtain governed by the shutter motor can be not only precisely controlled but also the durability and the reliability are increased. The experiment results have shown that this new shutter has the higher stability of movement long life span with more than 105 operating times a wide range of exposure time from1/ 50s to 1/ 320s(depending on the slit width)and the exposure error is less than 10%. With the CCD gain adjustment the performance of this shutter is fully satisfied with the requirements of area CCD aerial cameras. 2010 IEEE.

Influence of spatial temperature distribution on high accuracy interferometric metrology (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: Yang H.; Zhang J.; Zhang J.; Zhang J.; Yan F.

收藏 | 浏览/下载：29/0 | 提交时间：2013/03/25

We calculate the influence of temperature change on the refractive index of air establish a model of air temperature distribution and analyze the effect of different temperature distribution on the high accuracy interferometric metrology. First a revised Edlen formula is employed to acquire the relation between temperature and refractive index of air followed by introducing the fixed temperature gradient distribution among the spatial grid within the optical cavity between the reference flat and the test flat of the Fizeau interferometer accompanied by a temperature change random function within each grid. Finally all the rays through the air layer with different incident angles are traced by Matlab program in order to obtain the final output position angle and OPD for each ray. The influence of different temperature distribution and the length of the optical cavity in on the testing accuracy can be analyzed through the RMS value that results from repeatable rays tracing. As a result the horizontal distribution (vertical to optical axis) has a large effect on the testing accuracy. Thus to realize the high accuracy figure metrology the horizontal distribution of temperature must be rigorously controlled as well as to shorten the length of the optical cavity to a large extent. The results from our simulation are of great significant for the accuracy analysis of interferometric testing and the research of manufacturing a interferometer. 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 OAI收割
2010 2nd International Conference on Industrial Mechatronics and Automation, ICIMA 2010, May 30, 2010 - May 31, 2010, Wuhan, China
作者: Zhang J.; Zhang J.; Zhang J.

收藏 | 浏览/下载：29/0 | 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

Novel method for optimizing polishing tool-path in CCOS based on weighted-iterative algorithm (EI CONFERENCE) 会议论文 OAI收割
4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies, November 19, 2008 - November 21, 2008, Chengdu, China
作者: Zhang X.-J.; Wang X.; Wang X.; Wang X.; Wang X.-K.

收藏 | 浏览/下载：47/0 | 提交时间：2013/03/25

In Computer Controlled Optical Surfacing (CCOS) polishing tool-path is the base of solving other control parameters such as dwell time. In order to improve the fabrication results of polishing off-axis aspheric a novel method to optimize the tool-path is discussed in this paper. The optimizing method named weighted-iterative algorithm is according to the balance principle of the particle system. The power factor of each dwell point represents the requirement of dwell density. Considering the factors which influence the polishing result the power factors cosist of three elements include constant error distribution and dwell distance of workpiece edge. The tool-path is solved by numerical iterative method. In the end an error data is simulated with actual parameters using the matrix-based algorithm with two different tool-paths. The one is X-Y uniform spacing model and the other one is to optimize it based on the first. The comparison shows that the results of the optimized one are much better than traditional one especially the rms convergence rate. Theory of the algorithm is simple and exercisable and it satisfies practical requirement as well. 2009 SPIE.

Configuring an electrostatic membrane reflector with potentials exerted on distributed electrodes (EI CONFERENCE) 会议论文 OAI收割
2009 IEEE International Conference on Mechatronics and Automation, ICMA 2009, August 9, 2009 - August 12, 2009, Changchun, China
作者: Zhang P.; Shi G.

收藏 | 浏览/下载：24/0 | 提交时间：2013/03/25

Electrostatic membrane reflector (EMR) is very promised for optical quality application with the merits of utra-lightweight and flexible. Configuring a circular membrane reflector with electrostatic potentials exerted on distributed electrodes can approximatively produce a parabolic shape. A 300mm EMR (made from polyimide) stretched by distributed electrodes below is designed and the number of concentric electrodes needed for membrane shape forming is analysed. First based on an analytical solution of Poisson's equation determine the membrane control matrix by finding influence functions of 3 concentric electrodes and 6 control points on membrane surface in order to compute the needed voltages exerted on the distributed electrodes by the method of least-squares fitting. Then the final shape solved by finite element analysis with ANSYS is contrasted with the paraboloid and deviates greatly when the central displacement of membrane is beyond 2.5mm but in this range increasing the number of electrodes and control points will get a better shape. The corresponding errors are analyzed and the control method is concluded. Only using the integrated method of analytical computation numerical analysis and experiment the membrane shape of certain central displacement can be exactly predicted and controlled. 2009 IEEE.

Study of navigation based on intelligent avatar with mobile virtual reality 会议论文 OAI收割
IET International Conference on Wireless Mobile and Multimedia Networks Proceedings, ICWMMN 2006,, Hangzhou, China, November 6, 2006 - November 9,2006
Jun, Ma; Hengjun, Zhu; Jianhua, Gong Source

收藏 | 浏览/下载：36/0 | 提交时间：2014/12/07

Recent advances in wireless communications and the hardware performance of handset devices make possible the combination of navigation technology with mobile virtual reality (MVR). In this paper we describe a navigation method that uses intelligent avatar (IA) and been realized in a distributed architecture. In the method complicated A* wayfinding algorithm is applied to obtain the set of smell points (SSP) on PC server (PCS) thereafter handset client (HC) will receive the SSP via wireless network and create an IA to lead the user along the route controlled by the SSP. During navigation the IA can apperceive the status of user's avatar in virtual environment regularly and then adjust its travel speed in order to complete harmoniously the navigation task for the user. Furthermore the rendering of IA adopts the technology of dynamic impostor and the method of distributed rendering. In order to reduce the occupation of wireless network bandwidth we present two methods and name them as levels of action (LOA) and simple texture compression.