【作者】 许祖茂；

【导师】 赖康生；

【作者基本信息】 大连理工大学 ， 光学， 2005， 硕士

【摘要】 激光多普勒测速仪是一种非接触测量固体表面运动速度的工具,由于具有不破坏被测表面,不打滑,精度高等优点,被广泛地用于科研领域和工业领域。激光多普勒测速仪的测量精度受很多因素影响:光电探测器、环境状况、频谱加宽,信号处理等。国内还没有测量固体表面运动速度的多普勒测速仪,所用仪器全都高价进口,国外虽然有成形的产品,但是对于固体激光多普勒信号的产生机理尚没有完善的理论阐述。因此,研制固体激光多普勒测速仪不仅意义重大,还有很好的市场前景。本文首先介绍了激光多普勒测速技术的发展历史、研究现状和发展趋势,然后介绍了多普勒测速仪的测量原理、测量方法、光路布置、信号处理。根据条纹模型和散射机理建立了固体激光多普勒测速的数学模型,并通过数值模拟,分析了固体激光多普测速多普勒信号的形成机理,且模拟详细分析了固体表面特性和测量精度之间的关系。多普勒测速仪能够精确的测量出固体表面运动速度,要求当被测固体的表面粗糙度在一定范围内,而且这个范围由条纹间距和有效探测体宽度决定。这对多普勒测速仪的研制、设计和应用都有具有一定的指导意义。最后,根据数值模拟结论和测速原理,在实验室搭建了一个固体激光多普勒测速系统,并且成功、准确地测量出固体表面运动速度。系统采用DSP处理器处理信号,具有实时、准确测量优点,适合于工业应用。为下一步的产品开发提供了可靠的理论和实验基础。更多还原

【Abstract】 Laser Doppler velocipedes (LDV) is a no-contact technique for speed measurement of moving solid-state surfaces, which is applied extensively in analysis of the motion of a solid body both in the scientific research and in the industrial experimentation fields with no damage to the surface and no slippage and high accuracy. The applicability and accuracy of the technique depend on the conditions in which the system operates: the characteristics of the surface measured, photoelectric detector, the environmental conditions, spectrum broadened, signal processing, etc. Our country import completely LDV for solid in high price" because of without native product and technology. Now, no theories can explain perfectly the reason of Doppler signal generating in LDV for solid, so developing the LDV for solid is very important and have a big potential market.In this paper, the history, status quo and trend of LDV is firstly introduced and the principle, method, optical design and signal processing of LDV is secondly summarized. Then based on a theoretic model of fringes and the principle of light interfering and scattering, a mathematic model of LDV for solid-state surfaces has been developed for analyzing the reason of Doppler signal forming and we analyze the relationship between the characteristics of the solid-state surface and the measurement accuracy for velocity through computer simulation in details, the results of experiment accord with the results of simulation exactly. The analysis leads to the conclusion that LDV system can measure precisely the speed of moving solid-state surface, which surface roughness within the range depending on the measuring volume and fringe spacing .The study is useful for the designing and application of LDV.At last, based on the result of numerical simulation and the theory of LDV, we design a LDV for solid in laboratory and measure accurately the velocity of solid surface in success. The system has the characters of real-time and precise because of using the digital signal processor (DSP), so it is suitable for industry application exactly. The study of LDV for solid surface offers the theory and experimental information for developing the commercial product.更多还原