发射环境下发射塔架振动参数分析处理方法

发布时间：2018-06-15 09:06

本文选题：振动参数 + 傅里叶变换　；参考：《中北大学》2016年硕士论文

【摘要】：运载火箭在发射过程中所形成的发射环境,使发射塔架承受一定程度的激振,这会对发射塔架造成相应的损坏,随着火箭发射次数的增加,发射塔架遭受的损坏逐渐积累,这会使发射塔架的状态变得不稳定,影响到火箭发射任务的成功与否,因此有必要对火箭发射时发射塔架所承受的振动强度进行测试,而运载火箭造成的发射环境是极其复杂恶劣的,这使测得的发射塔架振动参数带有一定的噪声,无法精确的为发射塔架所承受振动强度的评估提供依据,因此本文研究发射环境下发射塔架振动参数的分析处理方法,从而为发射塔架的健康评估和寿命预测提供依据。在对发射塔架振动参数测试仪的变送器和采编存储器设计方案以及电路设计进行介绍的基础上,采用发射塔架振动参数测试仪测得发射塔架两个不同测点的振动参数,并绘制出振动参数波形图。分析了傅里叶变换、小波变换和小波包变换的优缺点和适用范围。傅里叶变换不适合对发射塔架振动参数这种非平稳信号进行降噪处理,而小波变换和小波包变换则适合处理非平稳信号,因此采用小波变换和小波包变换对振动参数进行降噪处理,并计算降噪后振动参数的信噪比和均方根误差,结果表明小波包变换对振动参数的降噪效果优于小波变换。振动参数经过降噪后,在主振频率、非平稳性和频带能量分布方面对振动参数进行了特征分析。采用傅里叶变换对振动参数进行频谱分析,为研究发射塔架的振动特性、振型和动力反应提供依据;采用小波变换对振动参数进行时频分析,为研究发射塔架振动参数非平稳随机特性提供依据;采用小波包变换对振动参数进行频带能量分析,计算各频带能量占总能量的百分比。综合这三种分析能够对两个振动参数对应的发射塔架测点处的损坏进行评估。通过上述方法对发射塔架振动参数进行处理和分析后,可以很好的为发射塔架在振动强度评估方面提供依据,符合本课题的研究目的。
[Abstract]:The launching environment formed by the launch vehicle during the launch process causes the launching tower frame to withstand a certain degree of excitation, which will cause corresponding damage to the launch tower frame. With the increase of the number of rocket launches, the damage to the launch tower frame gradually accumulates. This makes the status of the launch tower frame unstable and affects the success of the rocket launch mission, so it is necessary to test the vibration intensity of the launch tower frame when the rocket is launched. However, the launch environment caused by the launch vehicle is extremely complex and harsh, which makes the vibration parameters of the launch tower have certain noise, which can not accurately provide the basis for the assessment of the vibration intensity of the launch tower frame. Therefore, this paper studies the analysis and processing method of the vibration parameters of the launching tower under launch environment, thus providing the basis for the health evaluation and life prediction of the launching tower. On the basis of introducing the design scheme of transmitter, acquisition memory and circuit design of the transmitter and acquisition memory of the testing instrument of the vibration parameters of the launch tower, the vibration parameters of the two different measuring points of the tower are measured by using the test instrument of the vibration parameters of the launching tower. The waveform diagram of vibration parameters is drawn. The advantages and disadvantages of Fourier transform, wavelet transform and wavelet packet transform are analyzed. Fourier transform is not suitable for noise reduction of non-stationary signals such as the vibration parameters of transmission tower, but wavelet transform and wavelet packet transform are suitable for processing non-stationary signals. So wavelet transform and wavelet packet transform are used to reduce the noise of vibration parameters, and the signal-to-noise ratio and root mean square error of vibration parameters are calculated. The results show that wavelet packet transform is better than wavelet transform in noise reduction of vibration parameters. After noise reduction, the vibration parameters are analyzed in terms of main frequency, non-stationarity and frequency band energy distribution. The Fourier transform is used to analyze the frequency spectrum of the vibration parameters, which provides the basis for the study of the vibration characteristics, modes and dynamic responses of the launch tower, and the wavelet transform is used for the time-frequency analysis of the vibration parameters. This paper provides the basis for studying the non-stationary random characteristics of the vibration parameters of the launch tower and uses the wavelet packet transform to analyze the frequency band energy of the vibration parameters and calculate the percentage of the energy of each frequency band to the total energy. Combined with these three kinds of analysis, the damage of the measuring point of the tower frame corresponding to the two vibration parameters can be evaluated. After processing and analyzing the vibration parameters of the tower, the method can provide a good basis for the vibration strength evaluation of the launching tower frame, which is in line with the purpose of this research.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V553

【参考文献】