FPGA在温、湿度监控系统中的应用

文章简述了模糊控制理论,介绍了一种基于FPGA的温、湿度监控系统模糊控制器,可以对粮仓、温室等温、湿度参数进行较为精确的控制,对温、湿度监控系统的智能化具有较为深远的意义。     

Realization of high speed transmission system of ICT based on USB 2.0

Aiming at solving the problems existing in the traditional data transmission system of Industrial Computerized Tomography (ICT), which usually uses PCI and ISA bus, resulting in high price, poor scalability, low transmission rate, complex fixing and complex routing, and cannot fulfill the demand for research and production, a set of ICT based USB 2.0 high speed data transmission system model is proposed. The system takes a FPGA chip as core logic control module, which controls communications with the USB chipset. The whole hardware designation is described in terms of the performance of reliable data transmission, high speed and stability. Experimental results show that the proposed method improves the system’〖KG*8〗s stability and reliability. It can satisfy the requirements of ICT transmission .     

用FPGA实现直接序列扩频通信

扩频通信作为第3代移动通信的核心技术,系统需要完成快速复杂的信号处理,对电路的处理速度提出了更高的要求。本文以直接序列扩频通信为对象,用软件Protel99SE设计了以FPGA芯片EP1C3T144C8N为核心的系统硬件电路,并将VHDL程序下载到硬件电路的EP1C3T144 C8N芯片中,得到了实际的较为满意的扩频信号波形,证明实现了扩频调制。实验结果表明本系统与传统的实现方式相比,系统的稳定性、可靠性和处理速度大大提高,减少了硬件延时,体现了FPGA的高速并行处理能力和全硬件实现的特点。     

精准有机肥施肥机的设计与试验

针对目前国内有机肥施肥机功能单一、撒施量和幅宽不可调节或调节范围小的现状,设计了一款精准有机肥施肥机,实现了大块肥料的二次破碎后撒施,肥料均匀性好;采用机械传动和液压传动相结合,实现拖拉机动力的合理使用;利用FPGA控制系统对输肥链板档位、肥门开度和肥料落点控制罩角度进行精准调节,实现了撒施量和撒施幅宽的可变,同时可对料箱内运行状况、撒施情况等实时监控。试验结果表明:施肥机破碎度高、撒施均匀性好,实现了自动驾驶及撒施量和撒施幅宽的精准可变控制,撒施幅宽4~7.2m,撒施量3495~5520kg/hm^2,纵向施肥变异系数20.7%,施肥量变异系数0.48%。     

基于FPGA的直流电机伺服控制系统设计

为了提高直流电机伺服控制系统的静态调节精度和动态范围,以FPGA为核心开发了电机控制系统,设计了数据采集电路和隔离驱动电路,控制策略采用速度、位置、电流三环控制,并用Verlog HDL语言实现了控制算法。此方案增强了电机负载能力和响应特性,在电机控制领域有着广阔的应用前景。     

FPGA-based wireless smart sensor for real-time photosynthesis monitoring

Photosynthesis is considered the most important physiological function because it constitutes the main biomass entrance for the planet and consequently it permits the continuance of life on earth. Therefore, accurate photosynthesis measurement methods are required to understand many photosynthesis-related phenomena and to characterize new plant varieties. This project has been carried out to cover those necessities by developing a novel FPGA-based photosynthesis smart sensor. The smart sensor is capable of acquiring and fusing the primary sensor signals to measure temperature, relative humidity, solar radiation, CO₂, air pressure and air flow. The measurements are used to calculate net photosynthesis in real time and transmit the data via wireless communication to a sink node. Also it is capable of estimating other response variables such as: carbon content, accumulated photosynthesis and photosynthesis first derivative. This permits the estimation of carbon balance and integrative and derivative variables from net photosynthesis in real time due to the FPGA processing capabilities. In addition, the proposed smart sensor is capable of performing signal processing, such as average decimation and Kalman filters, to the primary sensor readings so as to decrease the amount of noise, especially in the CO₂ sensor while improving its accuracy. In order to prove the effectiveness of the proposed system, an experiment was carried out to monitor the photosynthetic response of chili pepper (Capsicum annuum L.) as case of study in which photosynthetic activity can successfully be observed during the excitation light periods. Results revealed useful information which can be utilized as new tool for precision agriculture by estimating the aforementioned variables and also the derivative and integrative new indexes. These indexes can be utilized to estimate carbon accumulation over the crop cycle and fast derivative photosynthesis changes in relation to the net photosynthesis measurement which can be utilized to detect different stress conditions in the crops, permitting growers to apply a correction strategy with opportunity.     

基于FPGA数字系统的硬件调试技术

现场可编程门阵列（FPGA）广泛应用于数字系统的设计，在数字系统中设计内置的信号发生器和嵌入的逻辑分析仪有助于系统硬件调试．分析了FPGA内置信号发生器实现原理和嵌入逻辑分析仪SignalTap II的配置，并给出了在研制1Gb／s光纤通道交换机过程中的系统硬件调试实例，丰富了硬件调试方法．     

CPLD/FPGA Programmable Logic Devices'' In System Reconfiguration Method

This article has discussed the methods of configuring the CPLD/FPGA devices based on SRAM, and choose the microprocessor to configure the FLEX10k devices of ALTERA. From the article ,we can see that this low cost and easy done method can enable the system to configure the CPLD/FPGA devices automatically as soon as the system is re set or power is re added to it. It has solved the problem that CPLD/FPGA devices based SRAM may lose it's logic function when dropped out of power, and it enables the single chip to have several functions.     

基于FPGA的温室灌溉智能测控系统

介绍了一种多参数温室灌溉智能测控系统的纯硬件实现.系统以Spartan-3A DSP FPGA为核心,对营养液混合过程中的营养液电导率和营养液酸碱度两个最重要的参数进行实时在线测量与控制,提出采用模糊逻辑控制技术来实现系统的有效控制,给出了基于Xilinx FPGA/CPLD开发平台和MATLAB/Simulink仿真环境进行DSP功能实现的方法和设计流程.实验仿真表明,系统设计紧凑、可靠,能够达到良好的控制效果.     

基于FPGA的无线气象传真图的识别

介绍基于FPGA接收JMH台的无线气象传真图的方案。此方案分为2部分：第1部分是将短波收信机接收到的SSB信号处理成调频传真信号;第2部分是将传真信号通过单芯片的FPGA转换成数字信号,进而在PC机上恢复和存储传真图像。气象传真图被存储在PC机上,可为航海气象信息的管理和利用提供方便。