直升机故障诊断振动信号预处理软件设计

发布时间：2018-10-04 22:15

【摘要】：直升机由于其灵活机变的模式,在现代战争中有着难以替代的地位。随着人们的生活水平提高,直升机作为一种特殊的交通工具在应急救援、医疗救护、救灾救生、交通监控、森林灭火等方面得到越来越多的应用。同时,直升机的安全问题也受到越来越多的人的重视。为了减少可避免的机械事故,各国都在开展在线或离线直升机故障诊断系统的研究。进行故障诊断的基础是直升机部件振动及相关信号的获取及预处理,对原始信号的预处理将降低噪声及干扰,为获取故障诊断所需的、准确的特征量提供基础。本课题针对直升机的振动信号的特点,在研究直升机故障诊断振动信号预处理方法的基础上实现对采集的振动信号进行有效的预处理,为进一步开展直升机故障诊断系统的研制奠定基础。本文针对直升机振动信号的特征,详细分析了振动信号预处理中常用的同步平均技术和小波变换的原理。以及在此基础上应用同步平均技术和小波变换技术进行消噪仿真实验,重点研究了将小波变换技术应用于消噪时小波基、阀值函数的选择。通过matlab的仿真实验,验证了所设计算法的可行性和有效性。考虑到本课题需在特定的硬件环境下实现对采集的振动信号进行有效的预处理,本文简要介绍了直升机轴承故障分析仪硬件电路的组成及工作原理,包括主控DSP系统、信号调理电路、A/D转换电路、PCI通信接口、PC/104模块等。在此基础上,详细描述了直升机故障诊断中振动信号预处理软件的设计与具体实现。整个软件包括PCI接口的驱动、API接口函数的设计,原始采样数据的读取及存储,以及对原始采样数据应用多周期同步平均及小波变换等方法进行预处理,最后数据的显示输出等。该软件在PC/104平台上采用Visual C++6.0编程软件进行开发实现。最后,对所设计的软件结合所针对的直升机轴承故障分析仪硬件进行联试与实验,以验证所设计的消噪算法的效果及软件程序的正确性。实验结果表明,同步平均技术和小波变换技术对振动信号的消噪具有明显效果。所设计软件具备了管理故障分析仪硬件及对采集的振动信号进行预处理的功能,为下一步研制直升机轴承故障分析与诊断系统创造了基础条件。
[Abstract]:Helicopter has an irreplaceable position in modern warfare because of its flexible model. With the improvement of people's living standard, helicopter as a special vehicle has been applied more and more in emergency rescue, medical rescue, rescue and rescue, traffic monitoring, forest fire extinguishing and so on. At the same time, more and more people attach importance to the safety of helicopters. In order to reduce the avoidable mechanical accidents, the research of online or offline helicopter fault diagnosis system has been carried out in many countries. The basis of fault diagnosis is the acquisition and preprocessing of helicopter components vibration and related signals. The preprocessing of the original signal will reduce the noise and interference and provide the basis for obtaining the accurate characteristic quantity needed for the fault diagnosis. According to the characteristics of helicopter vibration signal, this subject realizes the effective preprocessing of the collected vibration signal on the basis of studying the preprocessing method of helicopter fault diagnosis vibration signal. It lays a foundation for the further development of helicopter fault diagnosis system. Aiming at the characteristics of helicopter vibration signal, this paper analyzes in detail the common synchronous averaging technique and the principle of wavelet transform in vibration signal preprocessing. On the basis of this, the simultaneous averaging technique and wavelet transform technique are applied to the simulation experiment of de-noising, and the selection of wavelet basis and threshold function when the wavelet transform technology is applied to de-noising is studied emphatically. The feasibility and effectiveness of the proposed algorithm are verified by matlab simulation. Considering that this subject needs to realize the effective preprocessing of the collected vibration signal under the specific hardware environment, this paper briefly introduces the composition and working principle of the hardware circuit of the helicopter bearing fault analyzer, including the main control DSP system. Signal conditioning circuit A / D conversion circuit PCI communication interface PCP 104 module and so on. On this basis, the design and implementation of vibration signal preprocessing software in helicopter fault diagnosis are described in detail. The whole software includes the design of the driver API interface function of the PCI interface, the reading and storage of the original sampling data, the preprocessing of the original sampling data using the methods of multi-period synchronous averaging and wavelet transform, and the display and output of the final data, etc. The software is developed on PC/104 platform with Visual C 6.0 programming software. Finally, the designed software is combined with the helicopter bearing fault analyzer hardware to test and experiment to verify the effect of the designed de-noising algorithm and the correctness of the software program. The experimental results show that the synchronous averaging technique and wavelet transform technique have obvious effect on the noise reduction of vibration signal. The designed software has the functions of managing the hardware of the fault analyzer and preprocessing the collected vibration signal, which creates the basic conditions for the further development of the helicopter bearing fault analysis and diagnosis system.
【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V267

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