波長信號的解調是實現光纖光柵傳感網絡的關鍵,基于現有的光纖光柵傳感器解調方法,提出一種基于FPGA的雙匹配光纖光柵解調方法,此系統是一種高速率、高精度、低成本的解調系統,并且通過引入雙匹配光柵有效地克服了雙值問題同時擴大了檢測范圍。分析了光纖光柵的測溫原理并給出了該方案軟硬件設計,綜合考慮系統的解調精度和FPGA的處理速度給出了基于拉格朗日的曲線擬合算法。 Abstract: Sensor is one of the most important application of the fiber grating. Wavelength signal demodulating is the key techniques to carry out fiber grating sensing network, based on Several existing methods of fiber grating sensor demodulation inadequate, a two-match fiber grating demodulation method was presented. This system is a high-speed, high precision, low-cost demodulation system. And by introducing a two-match grating effectively overcomes the problem of double value while expands the scope of testing. This paper analyzes the principle of fiber Bragg grating temperature and gives the software and hardware design of the program. Considering the system of demodulation accuracy and processing speed of FPGA,this paper gives the curve fitting algorithm based on Lagrange.
上傳時間: 2014-07-24
上傳用戶:caiguoqing
Abstract: This application note illustrates the flexibility of the MAX7060 ASK/FSK transmitter. While the currently available evaluationkit (EV kit) has been optimized for the device's use in a specific frequency band (i.e., 288MHz to 390MHz), this document addresseshow the EV kit circuitry can be modified for improved operation at 433.92MHz, a frequency commonly used in Europe. Twoalternative match and filter configurations are presented: one for optimizing drain efficiency, the other for achieving higher transmitpower. Features and capabilities of earlier Maxim industrial, scientific, and medical radio-frequency (ISM-RF) transmitters areprovided, allowing comparison of the MAX7060 to its predecessors. Several design guidelines and cautions for using the MAX7060are discussed.
上傳時間: 2013-11-14
上傳用戶:swaylong
為了能夠滿足基站易于選址、優質快速的建站要求和易維護、低成本、高可靠的運行要求,本文對以方艙來實現一體化結構基站做出一番探討。從系統設計的觀點闡述了移動通信高性能基站天線設計的幾個關鍵問題,介紹了智能天線技術在基站中的應用,并且用HFSS軟件仿真了一種新型的對稱陣子天線,該天線駐波比小于2的帶寬可以達到60%,具有良好的寬頻帶特性。 Abstract: In order to meet the station construction requirement of easy site selection and fast base station, and meet the operational requirement of easy maintenance, low cost and high reliability, this paper discussed the unified architecture base station using shelter. Several key problems of high performance mobile communication base station antenna were illustrated from the view of system design, the application of smart antenna in base station was also introduced. And a novel dipole antenna was simulated by using HFSS, the VSWR of the antenna is less than 2, and the bandwidth was reach to 60%. So it has good broadband properties.
上傳時間: 2013-11-20
上傳用戶:linlin
闡述了軌道交通列車定位技術。介紹了在軌道交通系統中列車定位技術的功能,國內外軌道交通中主要采用的列車定位方法,重點論述了幾種主要定位技術,并從定位精度、閉塞制式、維護投資成本、抗干擾等方面進行分析比較。提出目前軌道交通定位技術應綜合運用,取長補短,多種方法相互融合,才能滿足軌道交通中對安全可靠性的要求。 Abstract: Rail train positioning technology is described. The paper introduces the funetions of the train positioning technology in the rail transit system, the main methods of train positioning do mestic and international rail, and focuses on Several key methods, analyzes and compares from the positioning accuracy, block system, maintenance and investment cost, interference and so on, suggested that the current rail positioning technology should be integrated use of positioning method of meriging, learn from each other, to meet the reliability requirements of rail safety.
上傳時間: 2013-11-25
上傳用戶:franktu
This white paper discusses how market trends, the need for increased productivity, and new legislation have accelerated the use of safety systems in industrial machinery. This TÜV-qualified FPGA design methodology is changing the paradigms of safety designs and will greatly reduce development effort, system complexity, and time to market. This allows FPGA users to design their own customized safety controllers and provides a significant competitive advantage over traditional microcontroller or ASIC-based designs. Introduction The basic motivation of deploying functional safety systems is to ensure safe operation as well as safe behavior in cases of failure. Examples of functional safety systems include train brakes, proximity sensors for hazardous areas around machines such as fast-moving robots, and distributed control systems in process automation equipment such as those used in petrochemical plants. The International Electrotechnical Commission’s standard, IEC 61508: “Functional safety of electrical/electronic/programmable electronic safety-related systems,” is understood as the standard for designing safety systems for electrical, electronic, and programmable electronic (E/E/PE) equipment. This standard was developed in the mid-1980s and has been revised Several times to cover the technical advances in various industries. In addition, derivative standards have been developed for specific markets and applications that prescribe the particular requirements on functional safety systems in these industry applications. Example applications include process automation (IEC 61511), machine automation (IEC 62061), transportation (railway EN 50128), medical (IEC 62304), automotive (ISO 26262), power generation, distribution, and transportation. 圖Figure 1. Local Safety System
上傳時間: 2013-11-14
上傳用戶:zoudejile
針對嵌入式機器視覺系統向獨立化、智能化發展的要求,介紹了一種嵌入式視覺系統--智能相機。基于對智能相機體系結構、組成模塊和圖像采集、傳輸和處理技術的分析,對國內外的幾款智能相機進行比較。綜合技術發展現狀,提出基于FPGA+DSP模式的硬件平臺,并提出智能相機的發展方向。分析結果表明,該系統設計可以實現脫離PC運行,完成圖像獲取與分析,并作出相應輸出。 Abstract: This paper introduced an embedded vision system-intelligent camera ,which was for embedded machine vision systems to an independent and intelligent development requirements. Intelligent camera architecture, component modules and image acquisition, transmission and processing technology were analyzed. After comparing integrated technology development of Several intelligent cameras at home and abroad, the paper proposed the hardware platform based on FPGA+DSP models and made clear direction of development of intelligent cameras. On the analysis of the design, the results indicate that the system can run from the PC independently to complete the image acquisition and analysis and give a corresponding output.
上傳時間: 2013-11-14
上傳用戶:無聊來刷下
波長信號的解調是實現光纖光柵傳感網絡的關鍵,基于現有的光纖光柵傳感器解調方法,提出一種基于FPGA的雙匹配光纖光柵解調方法,此系統是一種高速率、高精度、低成本的解調系統,并且通過引入雙匹配光柵有效地克服了雙值問題同時擴大了檢測范圍。分析了光纖光柵的測溫原理并給出了該方案軟硬件設計,綜合考慮系統的解調精度和FPGA的處理速度給出了基于拉格朗日的曲線擬合算法。 Abstract: Sensor is one of the most important application of the fiber grating. Wavelength signal demodulating is the key techniques to carry out fiber grating sensing network, based on Several existing methods of fiber grating sensor demodulation inadequate, a two-match fiber grating demodulation method was presented. This system is a high-speed, high precision, low-cost demodulation system. And by introducing a two-match grating effectively overcomes the problem of double value while expands the scope of testing. This paper analyzes the principle of fiber Bragg grating temperature and gives the software and hardware design of the program. Considering the system of demodulation accuracy and processing speed of FPGA,this paper gives the curve fitting algorithm based on Lagrange.
上傳時間: 2013-10-10
上傳用戶:zxc23456789
Integrated EMI/Thermal Design forSwitching Power SuppliesWei ZhangThesis submitted to the Faculty of theVirginia Polytechnic Institute and State Universityin partial fulfillment of the requirements for the degree of Integrated EMI/Thermal Design forSwitching Power SuppliesWei Zhang(ABSTRACT)This work presents the modeling and analysis of EMI and thermal performancefor switch power supply by using the CAD tools. The methodology and design guidelinesare developed.By using a boost PFC circuit as an example, an equivalent circuit model is builtfor EMI noise prediction and analysis. The parasitic elements of circuit layout andcomponents are extracted analytically or by using CAD tools. Based on the model, circuitlayout and magnetic component design are modified to minimize circuit EMI. EMI filtercan be designed at an early stage without prototype implementation.In the second part, thermal analyses are conducted for the circuit by using thesoftware Flotherm, which includes the mechanism of conduction, convection andradiation. Thermal models are built for the components. Thermal performance of thecircuit and the temperature profile of components are predicted. Improved thermalmanagement and winding arrangement are investigated to reduce temperature.In the third part, Several circuit layouts and inductor design examples are checkedfrom both the EMI and thermal point of view. Insightful information is obtained.
上傳時間: 2013-11-16
上傳用戶:萍水相逢
This algorithm was developed by Professor Ronald L. Rivest of MIT and can be found presented in Several languages. What I provide to you here is a C++ derivative of the original C implementation of Professor Rivets. The library code itself is platform-independant and has been tested in Redhat Linux. I ve included the sample code and makefile that I used for the Linux test. The demo, however, was written with Visual C++ 6 on a Windows 2000 platform.
標簽: L. Professor algorithm developed
上傳時間: 2014-12-21
上傳用戶:gonuiln
BonkEnc is a CD ripper and audio encoder for various formats. It can produce MP3, Ogg Vorbis, BONK, AAC and VQF files. BonkEnc supports freedb (CDDB), CD-Text and ID3 tags and is available is Several languages
標簽: BonkEnc encoder formats produce
上傳時間: 2015-01-14
上傳用戶:ywqaxiwang