System Generator for DSP是业内领先的高级系统级FPGA开发工具.本文基于该软件设计并实现了4通道GPS信号捕获模块,其中包括平均采样、本地C/A码、FFT/IFFT运算、复数乘法运算、扫频控制和结果返回等6个模块,并利用Xilinx的Viertx-5XC5V...System Generator for DSP是业内领先的高级系统级FPGA开发工具.本文基于该软件设计并实现了4通道GPS信号捕获模块,其中包括平均采样、本地C/A码、FFT/IFFT运算、复数乘法运算、扫频控制和结果返回等6个模块,并利用Xilinx的Viertx-5XC5VSX50T-FF665芯片对模块进行了硬件协同验证.测试结果表明:设计实现的捕获模块能够准确地捕获GPS信号,与利用硬件描述语言的方法相比,本文的方法大大缩短了开发周期.展开更多
针对粒子滤波计算量大、硬件实现困难的问题,提出了一种用于纯方位跟踪的简化粒子滤波算法,并通过Xilinx System Generator在FPGA上实现。首先,对通用粒子滤波算法进行适当简化,使其减少计算量并且易于硬件实现;其次,采用模块化设计,利...针对粒子滤波计算量大、硬件实现困难的问题,提出了一种用于纯方位跟踪的简化粒子滤波算法,并通过Xilinx System Generator在FPGA上实现。首先,对通用粒子滤波算法进行适当简化,使其减少计算量并且易于硬件实现;其次,采用模块化设计,利用状态机综合并实现各个模块的时序控制;最后,转换为硬件语言,完成硬件仿真。仿真结果表明,所设计的简化粒子滤波算法各个模块工作正常,且具有较好的跟踪精度及运行速度,可用于非线性、非高斯系统的粒子滤波实现,对于粒子滤波的硬件实现方面具有一定的参考价值。展开更多
对2007年版《IEEE Guide for AC Generator Protection》中失磁保护定值整定的几个问题提出不同意见。明确指出:发电机失磁故障必有滑差(s),其平均异步阻抗Xd(js)Xd(s=0),失磁保护中的阻抗元件下端定值为-Xd,已有足够余度,不应该是-(1.1...对2007年版《IEEE Guide for AC Generator Protection》中失磁保护定值整定的几个问题提出不同意见。明确指出:发电机失磁故障必有滑差(s),其平均异步阻抗Xd(js)Xd(s=0),失磁保护中的阻抗元件下端定值为-Xd,已有足够余度,不应该是-(1.1～1.25)Xd;在P-Q坐标与R-X坐标的转换公式中,U值应由"失磁保护动作滞后于低励限制线(UEL)"原则来确定,不应主观选择0.95UN。展开更多
目前在GPS接收机中,对码的捕获一般有两种方法:串行搜索方法和并行搜索方法。串行搜索方法硬件实现简单,但其捕获时间较长,计算量大,完成一个码搜索需约2分钟左右时间。导航接收机需要较高的数据更新率,这就要求捕获时间变得更短。重点...目前在GPS接收机中,对码的捕获一般有两种方法:串行搜索方法和并行搜索方法。串行搜索方法硬件实现简单,但其捕获时间较长,计算量大,完成一个码搜索需约2分钟左右时间。导航接收机需要较高的数据更新率,这就要求捕获时间变得更短。重点研究在SDR(Software Defined Radio)平台上通过FFT实现频域并行快速捕获算法。使用Xilinx公司的系统级建模工具System Generator完成对XCVFX60FF1152这款V4系列的FPGA芯片编程,完成了频域捕获算法的硬件实现,并验证了结果的正确性。展开更多
Air-bubble generator is the key part of the self-inspiration type swirl flotation machines,whose flow field structure has a great effect on flotation.The multiphase volume of fluid(VOF),standard k-ε turbulent model a...Air-bubble generator is the key part of the self-inspiration type swirl flotation machines,whose flow field structure has a great effect on flotation.The multiphase volume of fluid(VOF),standard k-ε turbulent model and the SIMPLE method were chosen to simulate the present model;the first order upwind difference scheme was utilized to perform a discrete solution for momentum equation.The distributing law of the velocity,pressure,turbulent kinetic energy of every section along the flow direction of air-bubble generator was analyzed.The results indicate that the bubbles are heavily broken up in the middle cross section of throat sect and the entrance of diffuser sect along the flow direction,and the turbulent kinetic energy of diffuser sect is larger than the entrance of throat sect and mixing chamber.展开更多
Synthesis of ultra-wideband （UWB） linear frequency modulation radar signals is a very important technology for microwave imaging, target identification and detection of low radar-cross-section （RCS） targets. A new...Synthesis of ultra-wideband （UWB） linear frequency modulation radar signals is a very important technology for microwave imaging, target identification and detection of low radar-cross-section （RCS） targets. A new method of UWB radar signals generation with two-channel signal generator is presented. The realization structure is given; the principle and errors of signal synthesis are analyzed. At the same time, an automatic .adjustment measure of signal phase is proposed because of phase discontinuity of waveform in this method. The simulation experiment and analysis results indicate that radar signals with large instantaneous bandwidth can be generated by means of this method on the condition that the high-speed digital devices are limited.展开更多
文摘System Generator for DSP是业内领先的高级系统级FPGA开发工具.本文基于该软件设计并实现了4通道GPS信号捕获模块,其中包括平均采样、本地C/A码、FFT/IFFT运算、复数乘法运算、扫频控制和结果返回等6个模块,并利用Xilinx的Viertx-5XC5VSX50T-FF665芯片对模块进行了硬件协同验证.测试结果表明:设计实现的捕获模块能够准确地捕获GPS信号,与利用硬件描述语言的方法相比,本文的方法大大缩短了开发周期.
文摘针对粒子滤波计算量大、硬件实现困难的问题,提出了一种用于纯方位跟踪的简化粒子滤波算法,并通过Xilinx System Generator在FPGA上实现。首先,对通用粒子滤波算法进行适当简化,使其减少计算量并且易于硬件实现;其次,采用模块化设计,利用状态机综合并实现各个模块的时序控制;最后,转换为硬件语言,完成硬件仿真。仿真结果表明,所设计的简化粒子滤波算法各个模块工作正常,且具有较好的跟踪精度及运行速度,可用于非线性、非高斯系统的粒子滤波实现,对于粒子滤波的硬件实现方面具有一定的参考价值。
文摘对2007年版《IEEE Guide for AC Generator Protection》中失磁保护定值整定的几个问题提出不同意见。明确指出:发电机失磁故障必有滑差(s),其平均异步阻抗Xd(js)Xd(s=0),失磁保护中的阻抗元件下端定值为-Xd,已有足够余度,不应该是-(1.1～1.25)Xd;在P-Q坐标与R-X坐标的转换公式中,U值应由"失磁保护动作滞后于低励限制线(UEL)"原则来确定,不应主观选择0.95UN。
文摘目前在GPS接收机中,对码的捕获一般有两种方法:串行搜索方法和并行搜索方法。串行搜索方法硬件实现简单,但其捕获时间较长,计算量大,完成一个码搜索需约2分钟左右时间。导航接收机需要较高的数据更新率,这就要求捕获时间变得更短。重点研究在SDR(Software Defined Radio)平台上通过FFT实现频域并行快速捕获算法。使用Xilinx公司的系统级建模工具System Generator完成对XCVFX60FF1152这款V4系列的FPGA芯片编程,完成了频域捕获算法的硬件实现,并验证了结果的正确性。
基金Project supported by the Scientific Research Foundation of Hebei University of Technology of China
文摘Air-bubble generator is the key part of the self-inspiration type swirl flotation machines,whose flow field structure has a great effect on flotation.The multiphase volume of fluid(VOF),standard k-ε turbulent model and the SIMPLE method were chosen to simulate the present model;the first order upwind difference scheme was utilized to perform a discrete solution for momentum equation.The distributing law of the velocity,pressure,turbulent kinetic energy of every section along the flow direction of air-bubble generator was analyzed.The results indicate that the bubbles are heavily broken up in the middle cross section of throat sect and the entrance of diffuser sect along the flow direction,and the turbulent kinetic energy of diffuser sect is larger than the entrance of throat sect and mixing chamber.
文摘Synthesis of ultra-wideband （UWB） linear frequency modulation radar signals is a very important technology for microwave imaging, target identification and detection of low radar-cross-section （RCS） targets. A new method of UWB radar signals generation with two-channel signal generator is presented. The realization structure is given; the principle and errors of signal synthesis are analyzed. At the same time, an automatic .adjustment measure of signal phase is proposed because of phase discontinuity of waveform in this method. The simulation experiment and analysis results indicate that radar signals with large instantaneous bandwidth can be generated by means of this method on the condition that the high-speed digital devices are limited.
