气固两相流信号自适应滤波方法研究

发布时间：2018-08-27 07:14

【摘要】：气固两相流广泛存在于工、农业生产中,准确测量其流体参数(速度、浓度等)对于生产过程中的节能环保、生产效率以及生产安全性至关重要。准确测量气固两相流参数最重要的是要能够获得良好的气固两相流信号,通过使用高质量的信号进行参数测量算法运算,能够提高气固两相流参数测量的精度。气固两相流信号是微伏级别的微弱信号,在复杂、恶劣的工、农业生产环境中,噪声和干扰会对气固两相流信号产生影响,造成信号的信噪比较低,这样非常不利于信号分析,所以要对信号进行滤波处理,气固两相流流型复杂,很难建立其数学模型,现场环境也是多变的,对于信号和噪声先验知识未知的信号,自适应滤波可以通过自身具有的跟踪和学习能力,调整滤波器参数到最优,实现最优滤波。本文通过对自适应滤波方法进行研究,主要研究了 LMS自适应滤波方法、RLS自适应滤波方法,以及将小波变换与自适应滤波方法相结合的基于小波变换的自适应滤波方法,分析了算法特性、存在的问题以及对其改进的算法,并将所研究的算法应用在气固两相流信号的处理上,先在气固两相流参数测量实验平台上采集气固两相流信号,运用采集到的数据在MATLAB中进行离线仿真,分析并验证算法可行性,然后将算法移植到TI公司TMS320F28335这一款DSP的开发环境中,实时的采集气固两相流信号,对采集到的气固两相流信号进行滤波处理,去除信号中的噪声和干扰。最后,以气固两相流流速作为评价指标,对比分析了滤波前后所得到的气固两相流参数(流速)的精度,通过多次实验,对比分析可以得出,加入了自适应滤波方法对气固两相流信号预处理后,得到了更精确的气固两相流固相颗粒流速。实验结果证明:通过对气固两相流信号进行自适应滤波处理,得到了高质量的信号,运用高质量的信号进行参数测量算法分析运算,能够提高气固两相流参数测量的精度。
[Abstract]:Gas-solid two-phase flow exists widely in industry. In agricultural production, accurate measurement of fluid parameters (such as velocity, concentration, etc.) is very important for energy saving and environmental protection, production efficiency and production safety. The most important thing in accurate measurement of the parameters of gas-solid two-phase flow is to obtain good signals of gas-solid two-phase flow. The precision of parameter measurement of gas-solid two-phase flow can be improved by using high quality signal to calculate the parameters. The gas-solid two-phase flow signal is a weak signal of microvolt level. In the complex, harsh industrial and agricultural production environment, noise and interference will affect the gas-solid two-phase flow signal, resulting in a low signal-to-noise ratio of the signal, which is very unfavorable to signal analysis. So to filter the signal, the flow pattern of gas-solid two-phase flow is complex, it is difficult to establish its mathematical model, the field environment is also changeable, for the signal and the signal with unknown prior knowledge of noise, The adaptive filter can adjust the filter parameters to the optimum through its own tracking and learning ability to achieve the optimal filtering. Through the research of adaptive filtering method, this paper mainly studies the LMS adaptive filtering method and the adaptive filtering method based on wavelet transform, which combines wavelet transform with adaptive filtering method. The characteristics of the algorithm, the existing problems and the improved algorithm are analyzed. The proposed algorithm is applied to the signal processing of gas-solid two-phase flow. Firstly, the signals of gas-solid two-phase flow are collected on the experimental platform of parameter measurement of gas-solid two-phase flow. Using the collected data to carry on the off-line simulation in MATLAB, analyze and verify the feasibility of the algorithm, then transplant the algorithm into the DSP development environment of TI Company TMS320F28335, and collect the gas-solid two-phase flow signal in real time. The collected gas-solid two-phase flow signal is filtered to remove the noise and interference. Finally, taking the velocity of gas-solid two-phase flow as the evaluation index, the accuracy of the parameters (velocity) of gas-solid two-phase flow before and after filtering is compared and analyzed. A more accurate flow velocity of gas-solid two-phase flow particles is obtained by adding adaptive filtering method to the pretreatment of gas-solid two-phase flow signal. The experimental results show that the high quality signal can be obtained by adaptive filtering of the gas-solid two-phase flow signal, and the precision of the parameter measurement can be improved by using the high-quality signal to analyze and calculate the parameters of the gas-solid two-phase flow.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN911.7;O359

【参考文献】