共查询到17条相似文献,搜索用时 807 毫秒
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基于小波变换的涡街流量计信号处理方法 总被引:26,自引:4,他引:22
涡街流量计有许多优点,应用比较广泛。但是,涡街流量计易于受到由管道振动和流场扰动引起的噪声干扰。涡待流量计中的处理电路不能保证仪表在工业现场的测量精度。本文研究基于小波变换的涡街流量计信号处理方法。本文介绍小波变换的基本原理和快速算法,分析小波滤波器的幅频特性,研究调整滤波器中心频率的方法,给出涡街信号的处理过程,进行仿真和实验测试。仿真和实验结果表明,小波变换能有效地减小了噪声影响,使频率测量的精度高,处理实时。小波变换是涡街流量计信号处理的一种新方法。 相似文献
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为了改善涡街流量计的性能,提出了一种基于卡尔曼滤波的涡街信号处理方法。根据涡街信号的特点,设计了一个线性涡街信号模型。结合模糊搜索和迭代算法,通过分析卡尔曼滤波器算法的原理和关键参数,改进卡尔曼滤波器算法。通过仿真模拟和实际流量实验验证了所提出的方法,并与其他方法进行了比较。实验结果表明,所提出的方法具有自适应滤波、更好的抗干扰能力和更快的滤波速度的优点。 相似文献
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基于FFT的频谱校正方法及应用 总被引:2,自引:0,他引:2
文章介绍了几种基于FFT的频谱校正方法,给出其基本原理和计算公式.将频谱重心校正方法应用于涡街流量计数字信号处理系统,实验结果表明该方法提高了流量计的测量精度. 相似文献
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基于DSP的低成本涡街流量计信号处理系统 总被引:1,自引:0,他引:1
涡街流量计易受噪声影响,现场测量精度得不到保证,节程比受限。本文选用片上资源丰富的TMS320LF2407A DSP芯片作为处理器,研制相应的数字信号处理系统。系统选用数宁滤波加频谱分析的信号处理方法处理传感器信号,提高仪表抑制噪声的能力,扩展量程比;模拟信号调理部分加入限幅滤波电路,解决传感器信号强度变化大、需要调整硬件电路参数的问题。该系统体积小、成本低、功能齐全,并可与不同口径的一次仪表匹配。目前该系统已通过实验标定,并应用于工业现场。 相似文献
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针对数字信号处理与低功耗之间的矛盾,为了满足一些工业现场对两线制电流传输的要求,研制了一种基于MSP430F1611单片机的低功耗、两线制涡街流量计数字信号处理系统.采用数字频谱分析与模拟带通滤波器组相结合的方式,既最大程度地滤除信号中混杂的噪声,提高测量精度,又保证低功耗工作;采用低功耗运放和数字电位器组成程控放大器,解决涡街传感器输出信号强度变化大的问题;采用独特的电源设计,为仪表两线制工作提供足够的电流. 相似文献
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漩涡频率检测是涡街流量计的关键技术之一。正比于流量的涡街频率信号变化范围较宽,对不同的测量介质和测量管道各不相同,在实际应用中并且混杂有各种干扰,因此,设法提高涡街频率的测量精度是一项非常困难但必要的工作。通过研究传统涡街频率检测电路,分析涡街频率信号的特点,在比较各种滤波方法和频率测量方法的基础上,提出通过自适应高阶低通滤波电路来削弱干扰信号,并采用自适应扩展周期方法来测量频率。该方法简单可行,仿真与实验结果表明,改进电路能有效削弱涡街流量信号的干扰,提高漩涡频率测量精度。 相似文献
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A set of digital signal processing method is formed by combining a digital band-pass filter, an adaptive lattice notch filter and the DTFT algorithm considering negative frequency contribution for processing the signals of Coriolis mass flowmeter. A digital Coriolis mass flow transmitter is developed with a DSP chip to realize the signal processing approach. Some effective measures are proposed to ensure high accuracy and real time of this approach in the implementation. Simulations, electrical signal tests and water flowrate calibrations are conducted to validate the performances of the method and the system. 相似文献
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数字式智能涡街流量计系统的设计 总被引:2,自引:0,他引:2
设计了以TMS320LF2407A为信号采集处理单元,P89LPC932为控制单元,配有LCD液晶显示模块和红外通讯接口的主从式数字式智能涡街流量计系统。针对目前涡街流量计易受干扰,精度不高的问题,信号采集处理单元采用基于DFT的频率估计方法,实现对传感器信号频率的估计。 相似文献
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In this paper, on an experimental facility, the measurement characteristics of a diameter 50 mm dual triangulate bluff body vortex flowmeter in steady flow and oscillatory flow were investigated. Then, the Hilbert Huang Transformation (HHT) method was used to assess the anti-interference performances and the vortex street stability in oscillatory flow for the dual triangulate bluff body vortex flowmeter and a single bluff body vortex flowmeter. Offline simulation was carried out on the anti-interference performances of the dual triangulate bluff body vortex flowmeter signal noise in oscillatory flow by the method of the EMD-scales filter. The major findings are: (a) in most case, the EMD-scales filter may be as good at de-noising effect for the dual bluff body vortex flowmeter in oscillatory flow than that for the single bluff body vortex flowmeter in oscillatory flow. The vortex street stability in oscillatory flow for the dual bluff body is similar to that for the single bluff body. (b) In some special case, the EMD-scales filter is unable to play a better de-nosing role for the dual bluff body vortex flowmeter in oscillatory flow. The invalid condition of the EMD-scales filter for the dual bluff body vortex flowmeter in oscillatory flow is different to that of the single bluff body vortex flowmeter and it was advanced in this paper. (C) The vortex street stability for the dual bluff body vortex flowmeter is better than that for the single bluff body vortex flowmeter. 相似文献
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In a vortex flowmeter vortices are generated by a bluff body, inserted in the path of flow, which has a piezoelectric sensor embedded in it. This piezosensor develops a signal having a fundamental frequency that is proportional to flow. The flow measurement relies completely on extraction of true vortex signal and estimation of the correct frequency. A novel adaptive FIR filter has been designed and implemented using low power computational resource (8.25 mW), which gives better results than an existing contemporary system when tested on an industrial flow rig. Further more a comparative study of autocorrelation, EMD Scales filter and proposed algorithm is carried on the good and bad vortex signals. From this comparative study it is seen that proposed algorithm is effective for bad vortex signals and low flowrates where vortex signals are weak. 相似文献
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数字滤波技术是数字信号处理的一个重要组成部分,滤波器的设计是信号处理的核心问题之一。本文根据IIR滤波器的设计原理,提出了MATLAB环境下基于双线性变换法的IIR滤波器设计方法,在该方法中只需要将数字滤波器的技术性能指标按双线性变换法转换为模拟滤波器的性能指标,再根据指定的模拟滤波器设计出相应的数字滤波器。文中给出了设计实例,仿真结果表明设计的各项性能指标均达到了指定要求,设计过程简便易行,MATLAB环境为设计IIR滤波器提供了一个可靠而有效的工作平台。 相似文献