共查询到20条相似文献,搜索用时 31 毫秒
1.
Model CL256 MOS Image Sensor is a newly developed solid image sensor, called self-scanned photodiode array(SSPD)abroad. Silicon gate P-MOS technique has been adopted in developing the device ,and a kind of three FETS dynamic circuit with varactor bootstrap has been adopted in developing the shift register used as scanned circuit. The circuit has the advantages of high speed and low power consumption. It is very important in developing high-oder digit SSPD devices. 相似文献
2.
A non-linear circuit model of photodiode built according to the working principle of self-scanned photodiode array image sensor is presented for improving the property of the sensor. Through the analysis of the non_linear circuit model,we get the state equations, and the equations are resolved with Runge_Kutta algorithm. The Runge_Kutta algorithm is realized in C language, and the numeric result of the circuit is obtained. The analysis of the numeric result of the model shows that the non_linear performance of the sensor can be improved by reducing the capcitor of the PN junction and the dynamic performance of the image sensor can be enhanced by paralleling capacitor C M , and all the analysis is consistent with the real measurement results of the sensor. The circuit model of photodiode is improved over previous model. 相似文献
3.
《保鲜与加工》2003,(10):101-103
Basing on the sampling and recovery theorem, this paper investigates the principle of equidistance subdivision for image sensor export signal by hardware circuit.The mechanism of the hardware equidistant subdivision and the function of the image sensor are analyzed, and the circuit diagram of the hardware equidistant subdivision is given with the export signal of the image sensor. Based this, the simulated experiment is a testing of the laser diffraction pattern by electronic CAD PSpice software. This simulated experiment shows that the method with the hardware equidistant subdivision can improve highly its measured accuracy (especially the device of low bit and big central distance), in Laser diffraction measure fine wire diameters, so this experiment can prove its true of the theoretical analysis. This method also eliminates nonuniformity of the device, to large extent, by low pass filter. 相似文献
4.
The CMOS image sensor has developed from passive pixel sensors and active pixel sensors to digital pixel sensors(DPS),which is the trend of image sensors.The advantage of DPS is that the imaging system can be integrated on a chip as imaging system-on-a-chip,decreasing the cost and power consumption,improving the imaging quality.The A/D conversion is the key component of the CMOS sensor.The authors analyze and compare the theories,performances and features of the chip level,column level and pixel level integrated ADC of the image sensor.They present the present and the future trend of the development about digital image sensor in the home and abroad. 相似文献
5.
Several kinds of microphone developed via silicon Micro Electro Mechanical System (MEMS) processes in recent years are investigated in this paper. The analysis and research of the merits and demerits of them show that: these conventional microphones mainly function as acoustic electric converters; the filtering against noise is implemented by a special filter circuit or a digital filter. Therefore, a design method for silicon micro array filter microphone is presented, where the filtering is achieved while converting signals. The effects of damping, silicon reed number and sensor element pair on dynamic characteristic are discussed; it follows that: Increasing damping can reduce microphone's sensitivity, while increasing silicon reed number can improve the sensitivity curve, furthermore, the implementation of the filter function is simultaneous with acquiring of the noise signal. 相似文献
6.
ZHANG Si-jie ZHAO Xiao-yu ZENG Xiao-ping PENG Cheng-ling GUO Xing-ming SHI Ling 《保鲜与加工》2011,(5):130-134
To solve the problem of low control accuracy and low stability of current X-ray machines, a kind of digital power supply for X-ray machine is introduced. In the digital power supply, some key technologies are used to improve the output stability of the high frequency inverter, including improved BUCK circuit for voltage regulating circuit, high frequency inverter and soft switching technology for the high-voltage generator. The PWM control technology is used to control the switch transistor of voltage regulating circuit and inverter circuit, which makes the drive waveform output stable and easy to control. In order to improve the control accuracy, reduce the volume and change high voltage consecutively, the software PID of the microcomputer is used to control the feedback circuit. The high-accuracy power chip is used for the filament power supply to make the filament electric current stable. Through the analysis of the circuit, the parameters of the circuit are calculated and the circuit is simulated by PSPICE software. The results show that the theoretical analysis is consistent with the practical simulation results. The design can meet the requirement of the technology indices of the power supply of the X-ray machines. 相似文献
7.
针对内蒙古自治区生态观测需求,特别是草地生态系统观测需求,选取牧草观测为研究内容,提出基于嵌入式技术和并行计算技术的实时远程可控可视的牧草观测自动化技术思路。采用特征像素图像识别方法,实现牧草覆盖度的自动测量、牧草的发育期图像自动识别。利用摄影测量技术结合图像处理技术获得像高转物高变换算法,实现层高与株高的自动测量。结合现代电子技术以及DSP技术、图像处理技术设计了牧草自动观测智能传感器,传感器在观测前端完成图像采集、处理与模式识别后,再将处理后的结果通过网络传向服务器端,可通过智能手机或PC访问服务器远程查看观测数据,实现牧草覆盖度、层(株)高以及牧草生长期的自动观测。测试结果表明,图像处理与实测覆盖度数值显著相关检验R0.05>0.90,与实测株高数值显著相关检验R0.05>0.85。相对于在后端PC系统进行图像处理,不但可以提高观测系统的数据运算处理速度,而且鲁棒性好,同时能够大大减轻数据传输压力,适合对体积、功耗、工作环境及稳定性要求极高的场合。 相似文献
8.
Considering the characteristics of the dc side series active power filter (APF) that the output voltage cannot be adjusted and the control circuit is complex , an improved single phase dc series APF topology is proposed. The improvement of the new circuit topology and fundamental working principle are analyzed. Following the circuit power factor pre regulator principle, the designing method for the main circuit parameters is given. The voltage ring and the current ring are designed by using the zero pole method. The main circuit power switch is controlled with the same frequencies, while the control circuit was simplified further. Compared with the paralleled APF, the main circuit of topology structure is simplified and the number of the active switches is reduced, which show low input current harmonics, high power factor, large voltage output adjustment range and low cost. The simulation results prove that the proposed topology is correct and reliable. 相似文献
9.
A novel single phase boost type power factor correction circuit is introduced .The converter's efficiency is greatly improved by improving on the traditional boost type power factor correction circuit. Integrate Reset Control circuit is adopted to realize unity power factor. The Integrate Reset Control high efficiency single phase boost type power factor corrector has these characteristics as follows: It's constant frequency operation, which is of advantage of the design of filter. The control circuit is very simple and no need for multiplier. The result is quiet perfect, the input current follows the input voltage very well. The efficiency is very high. The result of simulation and experiment proves the correction of theory analysis. 相似文献
10.
A novel design is presented to defend against electromagnetic interference (EMI) in a high speed data acquisition system. Problems that affect signal integrity (SI) in high speed image acquisition systems, such as reflection, crosstalk and ground bounce, are deeply analyzed in a manner consistent with transmission line theory. The results can theoretically inform EMI design of important networks, including system power, ground, clocks, high speed wires and decoupling capacitors. Experiments simulating print circuit board(PCB) reflection and EMI on high speed signal wires between DM642 and SDRAM are conducted. The power and ground should be placed separately in different layers. The clock lines passing through holes should be as few as possible. The signal lines should be as close to the same length as possible. The results show that amplitude of the signal overshoot is less than 0.7 V and the EMI amplitude is within the federal communications commission(FCC) standard. 相似文献
11.
Based on the principle of electromagnetic induction of exchange and the measurement principle of the ring space array torque which is related to the sphere symmetry, the measurement principle of a ring space array torque sensor is discussed which is fit for measuring in extreme environment. The reader head electrocircuit is designed which is combined with the problems on measurement of mechanical torque in extreme environment. The experimentation is emulated and the preferably satisfied result is gained. 相似文献
12.
邹小波 《农产品加工.学刊》2012,(11):9-13
食品腐败变质是引起食品安全问题的重要原因之一,为了探索绿色、快速的食品腐败变质检测和监测方法,提出以天然色素为新型气敏材料的气味可视化检测方法。以桃花、映山红、紫薯、黑米为原料,采用无毒无害方式提取其中的天然色素(桃花色素、映山红色素、紫薯色素和黑米色素),并研究了4种天然色素在不同pH值条件下的显色特性;选取对pH值显色敏感的天然色素作为气体敏感材料,固定于基底材料制成可视化传感器;并用于检测猪肉变质过程中产生的气味。结果表明,以天然色素为气敏材料的可视化传感器能够检测食品腐败变质产生的气味。该新型传感器与文献已报道的可视化传感器相比,具有不包含对人体有害的化学成分,检测过程中不会污染检测样本等优点,但应用时应避光。 相似文献
13.
In order to improve waveform performance of light HVDC system, a lot of switches which operate in high frequency are used, which causes large switching losses and results high cost. A new Buck type voltage source converter(BVSC) is proposed. The new BVSC comprises a dual-buck converter and a three-phase inverter operating in grid frequency. Only two high frequency switches are used, which results good output waveform performance. In order to reduce the high frequency switching losses, a novel improved double-frequency Buck type voltage source converter(DBVSC) is also proposed. An additional dual-Buck converter is added to the BVSC, the added dual-Buck converter deals with the fundamental power that operates in low frequency, and BVSC only deals with harmonic power that operates in high frequency. The output waveform is enhanced and the switching losses are reduced in DBVSC, and the power rating is also increased. The DBVSC is very suitable for large power rating application. The one cycle control theory is adopted to control the proposed DBVSC with analog circuit, which is very simple. The proposed DBVSC and control method are verified by simulation. 相似文献
14.
Li Hengsheng 《保鲜与加工》1989,(4)
In general,the calculating result of a comparatively regular frame-shearing wall system in tall buildings,a 4-order differential equations are established according to the deformation-coordination of beams,columns and four
boundary conditions.Then a series of formulas concerning internal forces and displacement is obtained These formulas are hyperbolic functions.This paper presents a method,which changes 4-order differential equations into 2-order and solves them by the expressions of new homogeneous solutionThen the formulas of internal forces and displacements become exponential functions By this method,the calculation is very convenient The result of suggested method agrees well with the general by comparison This paper is also applicable to buildings with
some part of different height of storey or stiffness. 相似文献
15.
CCD radiation temperature measurement method for hot continuous casting billet surface 总被引:2,自引:0,他引:2
According to the present research status and existing problems of hot continuous billet surface temperature non contact measurement technology, a real time temperature measurement model, which combines two-color(R,G) and monochrome (B) of surface radiation image, is established. The surface image is collected through tricolor charge coupled device (CCD) sensor, at the same time, the temperature dynamic response range of CCD can be improved by controlling integrated time and setting different apertures. Through computer image process technology, multi-point temperature can be measured simultaneously, and 2-D temperature field distribution on continuous casting billet surface can be realized. It is be proved by theory and application that the model and method can provide a theory and technology support for realizing surface temperature field on-line measurement for continuous casting billet. 相似文献
16.
To prevent the duty cycle loss of full-bridge converter controlled by the phase-shifting method, a high frequency high voltage X-ray power supply is proposed. It combines full bridge LLC(FB-LLC) series resonant converter with bipolar single-phase symmetrical voltage multiplier. FB-LLC series resonant, high voltage transformer and bipolar single-phase symmetrical voltage multiplier are used in the main circuit. The LLC series resonant circuit and working conditions of soft switch are analyzed. The fundamental harmonic approximation model is established. The parameters of the main circuit are designed. The simulation results show that the output voltage adjusted continuously within 40~120 kV and without duty cycle loss. The X-ray power supply is proposed to achieve a quick rise and low ripple of output voltage. According to the simulation results, the proposed topology is correct and reliable. 相似文献
17.
Because any type of image sensor has the inevitable question of nonuniformity which directly affect the quality of image and its using range, the paper discusses the principle and algorithm of multi-point nonuniformity correction and designs the scheme of nonuniformity correction based on Complex Programmable Logic Device (CPLD). The CL512J Self Scanned Photodiode Array(SSPA) image sensor is used in the nonuniformity realtime correction experiment. The result of experiment shows the correction system can reduce the nonuniformity of this image sensor from 40% to 2%. 相似文献
18.
A piezoelectric biosensors for detection of plasm viscosity is developed, which is based on liquid damping effect of quartz crystal resonator. The measuring principal is given. Simultaneously, the detector of sensor and oscillator circuit is developed. The test results show that the maximal frequency shift of sensor are linearly dependent on square root of viscosity. The proposed sensor is much more simpler, more sensitive than the traditional methods. Furthermore, The sensor can be used to on-line detection. 相似文献
19.
基于LabVIEW的潜油电泵数据采集系统 总被引:1,自引:0,他引:1
应用LabVIEW虚拟仪器现场可编程门阵列(FPGA)对潜油电泵的电压、电流参量进行实时数据采集,通过上位机对采样数据进行分析处理,得到潜油电泵的视在功率、有功功率、无功功率和功率因数,并与电能质量检测仪检测数据进行对照。系统硬件采用NI sbRIO-9606和NI9683夹层板配合使用,突破了传统的依靠DAQ助手的硬件采集,基于现场可编程门阵列(FPGA)的数据采集系统,由软件构成采集功能芯片,可控性强,准确性高,应用性好。实验表明,该系统在误差允许范围内能够对数据进行准确采集。 相似文献
20.
A hybrid power supply is composed by both a linear and a switching source connected in parallel and it can improve the dynamic response. But the hybrid power supply cant not effectively reject the perturbations in the power supply. A hybrid power supply based on one cycle control theory is proposed in order to improve the capability and the control precision. A switching source based on one cycle control is adopted in the hybrid power supply. The analysis results indicate that the hybrid power supply can effectively reject the perturbations in the power supply. And the analysis results also show that not only the control precision is improved, but also the control circuit is simple. The simulation resuits given verify the correctness and effectiveness of the proposed method. 相似文献