百瓦级激光功率的测量方法研究

发布时间：2018-12-20 09:00

【摘要】：随着激光加工技术的蓬勃发展,工业生产中对激光质量的要求也在不断的提高。激光功率是激光器的一个重要参数,决定了其适用的领域和范围。激光加工过程中,特别在长时间的加工处理过程中,激光功率的衰减,严重地影响产品的加工质量与加工效率。因此,如果能在加工过程中对激光的功率随时监测,对于提高产品的质量与合格率有着重要意义。基于此,本文运用宽范围温度检测技术,设计了一套高灵敏度的热电式激光功率测量系统。针对本系统,研究内容主要包含以下几点。首先,介绍了一些国内外常用的激光功率的测量方法,在这些方法的基础上设计了一套激光功率测量系统。该系统利用激光的辐射特性和转换效应,通过对能量、功率、温度三者的内在关系进行分析,确定了激光功率的测量方案。其次,阐述了测量系统的总体实施方案。利用激光探测传感器将功率信号转化为温度信号后,通过外围的系统电路及STM32对温度信号进行采集,再由采集到的温度曲线反推出激光的功率。在此基础上建立了测量系统的物理模型与数学模型,并对测量系统中核心模块激光探测传感器进行了设计。然后,根据系统的测量原理,设计了一种基于热敏电阻的宽范围温度测量方法。该方法利用RC一阶电路系统产生的充放电时间与热敏电阻阻值存在的数学关系,实现了对热敏电阻阻值的测量,再通过热敏电阻阻值与温度的关系计算得出测量所需的温度值。依据此方法设计了系统的测量电路,其中包括RC一阶电路、比较电路和满足初始充放电条件的二次充放电电路,并结合STM32实现了温度测量电路中的方波输入、充放电时间的获取以及二次充放电的控制。最后,对测量系统进行调试与实验验证,通过实验模拟不同激光功率作用下的传感温度曲线,对其分析后提出了一种基于曲线拟合的功率求解方法。通过与标准功率计的比对实验表明了文中设计的关于激光功率测量系统的可行性。
[Abstract]:With the rapid development of laser processing technology, the requirement of laser quality in industrial production is improving. Laser power is an important parameter of laser, which determines its application field and scope. In the process of laser processing, especially in the process of processing for a long time, the attenuation of laser power seriously affects the quality and efficiency of the products. Therefore, if the laser power can be monitored at any time in the process of processing, it is of great significance to improve the quality and the qualified rate of the product. Based on this, a thermoelectric laser power measurement system with high sensitivity is designed by using wide range temperature detection technology. In view of this system, the research content mainly includes the following several points. Firstly, some commonly used laser power measurement methods at home and abroad are introduced, and a laser power measurement system is designed on the basis of these methods. Based on the radiation characteristics and conversion effect of laser, the measurement scheme of laser power is determined by analyzing the relationship among energy, power and temperature. Secondly, the overall implementation scheme of the measurement system is described. After converting the power signal into the temperature signal by using the laser probe sensor, the temperature signal is collected through the peripheral system circuit and STM32, and the laser power is deduced from the collected temperature curve. On this basis, the physical and mathematical models of the measurement system are established, and the laser detection sensor, the core module of the measurement system, is designed. Then, according to the measuring principle of the system, a wide range temperature measurement method based on thermistor is designed. Based on the mathematical relation between charge and discharge time and resistance of thermistor produced by RC first order circuit system, the measurement of resistance value of thermistor is realized, and the necessary temperature value is obtained by calculating the relationship between resistance value of thermistor and temperature. According to this method, the measuring circuit of the system is designed, which includes the RC first order circuit, the comparison circuit and the secondary charge and discharge circuit which satisfies the initial charge and discharge conditions. The square wave input in the temperature measurement circuit is realized with STM32. The acquisition of charge and discharge time and the control of secondary charge and discharge. Finally, the measurement system is debugged and verified by experiments. The sensing temperature curves under different laser power are simulated experimentally, and a power solution method based on curve fitting is proposed. The comparison experiment with the standard power meter shows the feasibility of the laser power measurement system designed in this paper.
【学位授予单位】：湖北工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN24

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