【作者】 赵新秋；

【导师】 郑绳楦；

【作者基本信息】 燕山大学 ， 电路与系统， 2003， 硕士

【摘要】 机械工程中测量轧制力的方法有两种：应力测量法和传感器测量法。应力测量法，由于中性面难以确定及四个立柱受力不均等因素，有时引起较大误差。传感器测量法，测力传感器分为电容式、压磁式、电阻应变式。其中以电阻应变式为主流，但它的测量精度易受电磁、温漂等因素干扰。本文设计了一种微分干涉式光纤应变传感器，通过测量轧机内安装的弹性元件的应变来测量轧制力，其结构简单，精确度及灵敏度高，易于安装与使用。 微分干涉式光纤应变传感系统由传感头、光路、光电转换电路、信号处理电路组成。本系统以安装于轧机内的弹性元件为第一敏感元件，把它的形变转换为光纤的应变，来调制光的相位。文中介绍了调制原理、选择弹性元件的原则，推导了传感头的数学模型。光相位的检测是采用萨格纳克微分干涉仪来实现的。文中设计了应用于本系统的干涉仪结构，推导了光路的数学模型。该干涉仪使调制相位被压缩了上百倍，提高了线性度，扩大了动态测量范围。对光强信号的检测，文中设计了集光电检测、电流-电压转换为一体的前置放大电路，提高电路性能的滤波电路，解相位压缩的积分电路。 在完成系统设计和元件优化选择后，以压电陶瓷替代轧机内的弹性元件，通过在其内外表面加驱动电压使其产生变形，用上述微分干涉式传感器测量该应变。实验表明，本文的设计是正确的、可行的。其精度达到了灵敏度为0.15V／με。本系统还适用于其他场合的动态应变、应力的测量，对环境噪声具有较好的抑制作用。更多还原

【Abstract】 There are two kinds of method to measure the rolling force: stress measure and sensor measure. Because it is difficult to find the center section and the force condition of four upright pillars is different, this method causes error sometimes. The measuring sensor is divided into the capacitance sensor, the pressure-magnetism and the resistance-strain sensor. The latter is popular, but its accuracy is easily disturbed by the factor electromagnetism, temperature and so on. A fiber-optic strain sensor based on a differentiating Sagnac interferometer is demonstrated to measure the rolling force by measuring strain of the elasticity element inside the rolling machine. The system is simple in structure and possesses high accuracy, super sensitivity. It is easy to be installed and used.The system consists of the sensor header, light path, pre-amplify, signal process circuit. The first sensitive part is the elasticity element installed inside the rolling machine whose strain is transformed into that of the optical fiber. The modulating principle and the rule to select the element is described. The formulas of sensor header is derived. Phase detect need a fiber-optic strain sensor based on a differentiating Sagnac interferometer. Structure of system is designed. The sensor can compress phase till hundreds of times and extends the range of dynamic measurement. The formulas of light path is presented. For detecting of light power, the pre-amplify, filtrating wave and integration circuit is designed.After the design of system and selection of element are completed, PZT is out of shape instead of the elasticity element in experiment. The result shows that the system designed in the article is correct. High accuracy at 0.18%, super sensitivity at 0.15V/ has been achieved. The system is used to measure other varying strain with good immunity of surrounding perturbation.更多还原