【作者】 梅森；

【导师】 崔贤玉；

【作者基本信息】 哈尔滨工业大学 ， 机械电子工程， 2010， 硕士

【摘要】 测试技术几乎涉及所有的工程技术领域,测试技术已经成为生产效率和制造能力的重要标志。多年来,为了提高生产效率和产品性能,各国大力发展自动测试系统及其相关技术。而我国对自动测试系统的研究较晚,尚不成熟,大部分精密测试设备都依靠进口且价格昂贵。如今虚拟仪器技术的出现,又给了我们新的发展契机。本文融合DSP技术和虚拟仪器技术,构建了测试信号处理分析系统,研制完成直升机自动测试系统中的虚拟示波器模块。不同于当前主流虚拟示波器结构“数据采集卡+上位机数据处理系统”,本文利用下位机DSP模块完成了数据采集功能和数据处理功能,避免了海量数据传输的问题,提高了系统实时性。上位机模块负责调度自动测试系统的各个模块的测试程序集。本文重点研究数字信号处理分析的相关理论及其在DSP模块上的实现。在数字滤波方面,应用MATLAB工具对Kaiser窗FIR低通滤波器进行了参数优化和仿真验证,使窗函数旁瓣引起的吉布斯现象对采样信号信息的影响降至最低。在频谱分析方面,分析了FFT频谱分析算法能量泄露的原因,并应用加Hanning窗的方法对FFT算法的能量泄露进行了抑制,但实验表明频谱分析误差仍较大。为进一步减小频谱分析误差,研究了由加Hanning窗FFT算法与窗的谱函数之间的关系推导出的Hanning窗比值法,并对加Hanning窗FFT频谱结果进行校正,实验结果表明比值校正法明显提高了FFT频谱分析的精度。研究了以提高频率分辨率为目的的FT频谱细化算法,对FFT离散频谱连续化的实验结果进行了分析,并与比值校正法的实验结果进行比较,分析了两算法校正结果的差异以及两者仍然存在误差的原因。在信号分析算法实现方面,采用IQ数据格式使定点DSP完成了高精度的浮点运算,且提高了系统的实时性。本文应用DSP模块对变频异步电机的电流信号进行了测试,测试结果表明DSP模块在强干扰的环境下,依然能够保持很高的测量精度,取得了良好的效果。更多还原

【Abstract】 Testing technology has been applied to most areas of engineering, which has become an important indicator of productive efficiency and manufacturing capabilities. In order to improve productive efficiency and product performance, lots of countries strived to develop automated testing techniques. But the research on the automatic test system is late in our country, so most of sophisticated testing equipments are imported. Today, the emergence of virtual instrumentation gives us a new opportunity for development.This paper has used DSP technology and virtual instrument technology to construct the signal processing and analysis system. It is the virtual oscilloscope module of helicopter automatic test system. The structure this paper has applied is different from the common structure of virtual oscilloscope. To avoid problems with large data transmission, the DSP module completed both data acquisition function and data processing function. It also improved real-time performance of the system.This paper focuses on digital signal processing and analysis theoretics, and their implementation on the DSP module. On the aspect of digital filtering, MATLAB tools are applied to design Kaiser window FIR low-pass filter, and optimize the parameters to reduce the Gibbs phenomenon, in order to obtain accurate information on the sampling signal. On the aspect of spectrum analysis, the causes of the energy leaking problem for FFT analysis are analyzed. The method of additional Hanning window FFT algorithm is applied to suppress the energy leakage, but experiments show that the error is still large. In order to rectify the results of the FFT spectrum, many methods are studied, such as interpolation correcting method and FFT+FT method. Both experimental results were analyzed and compared, and the difference of the two algorithms was studied. The reasons of error by the two algorithms are also given out. On the aspect of the realization for signal analysis algorithms, IQ data format is used to complete a high-precision floating-point operations on the fixed-point DSP.In this paper, DSP module is applied to test the current signal of the motor. Test results show that the DSP module was still able to maintain high accuracy in the environment of strong electromagnetic interference.更多还原