【作者】 于雷；

【导师】 刘薇娜；

【作者基本信息】 长春理工大学 ， 机械制造及其自动化， 2014， 博士

【摘要】 材料在环境作用下发生腐蚀是一种常见的现象,每年都会给世界各国造成数百亿美元的损失。在多盐、潮湿的气候环境下,腐蚀现象更容易发生。盐雾试验作为测定材料抗腐蚀性能的最重要方法之一,在世界各国被广泛使用。盐雾沉降率反映着盐雾的腐蚀特性,是盐雾试验中的一个重要参数。实验过程中需要实时控制盐雾沉降率在1～2mL/80cm2·h范围内。盐雾沉降率的评定是以单位时间、单位面积内的盐水凝结体积为指标的。盐雾试验的工作条件非常恶劣,人工对盐雾沉降率的检测已经越来越无法满足现代工程测量的需求。基于国内外盐雾沉降率液位测量与控制系统的理论与技术现状,本文应用激光三角法非接触性测量的方法对盐雾沉降率进行了在线高精度自动测量技术的研究。根据盐雾试验要求试验区域内各处沉降率应保持一致的特点,论文提出了一套面向多个受检对象的液位巡检技术方案。可以利用直线电机带动一套测量装置实现了对12个观测位置进行连续48小时的液位自动检测,同时,为避免盐雾干扰检测过程,采用了柔性管连接远距离液位变化参数提取的新方案,既保证了检验精度,又改善了检测操作环境。研制了盐液液位检测原理分析、对比试验装置。采用了RBF神经网络的方法和最小二乘法对直射式激光三角法的液位测量系统进行了修正。通过实验数据结果表明：实验装置能准确的测量液位高度值。提出并建立了针对液位测量系统的5自由度动力学模型,推导出动态响应数学模型,在此基础上,应用有限元分析ANSYS软件对系统进行模态分析,计算了系统5阶固有频率和振动型态,对检测系统关键部件也进行了应力、应变分析与验证。针对检测装置受到外部系统性振动干扰的问题,进行了振动分析和减振处理,并利用Matlab软件进行了计算机仿真分析。针对液位测量系统需要快速、精确定位和存在振动等干扰因素的具体情况,采用零相差跟踪控制(ZPETC)和扰动观测器(DOB)结合的零相差跟踪鲁棒控制方式作为巡检系统直线电机控制策略。可以有效地减小跟随误差,提高运动的精度。扰动观测器使得系统具有较强的干扰抑制能力,并满足鲁棒性要求,使液位检测过程能有更多的稳定有效工作时间。利用LabVIEW虚拟仪器技术,开发了具有自主知识产权的盐雾沉降率测量系统的控制软件,软件对采集和运动系统进行联合控制,保证信号采集的准确性和稳定性,分析软件可以通过图形和数字两种形式实时计算、显示液位和沉降率的情况。该软件系统还可以完成报警、信息存储、打印等功能。克服了以往由人工进行采集、分析、资料整理的诸多不便。对系统的测量精度进行了试验验证,分析了测量结果的可靠性和准确性,对系统产生误差的主要因素进行了探讨。精度实验表明：该系统的绝对测量精度和重复性测量精度均在10μm以内,,满足了盐雾沉降率液位测量的精度要求。通过实验研究,证明了盐雾沉降率液位测量系统的可行性、先进性、可靠性及实用性。更多还原

【Abstract】 The materials in the environment under the action of corrosion are a common phenomenon. The more salt, humid climate environment, the corrosion phenomenon occurs more easily.It is the most important methods that the salt spray test as a measured material the corrosion resistance of is widely used in the world. Fog deposition rates reflect the salt spray corrosion characteristics, is an important parameter in the salt spray test. Need real-time control experiment fog deposition rates in the range of1Φ2mL/80cm2·h. Evaluation of fog deposition rates per unit time is, the volume of brine condensation within the unit area as an index. In this paper, the salt spray interference environment fog deposition rates, high precision automatic measurement technology.In this paper, laser triangulation method of non-contact measurement method based on the theory and technology status of level measurement and control system of fog deposition rates at home and abroad, the brine liquid level line automatic measurement.According to the salt spray test requirements throughout the sedimentation rate consistent requirements, the paper presents a set of multiple subjects’object-oriented level inspection program. Linear motor driven by a set of measuring devices can take advantage of continuous48-hour level of12observation position automatically detect the same time, in order to avoid the salt spray interference detection process, using flexible tube connected to distant level monitoring program, both ensure test accuracy, detection improved operating environment.The liquid level detection exam device has been built. RBF neural network method of direct laser triangulation level measurement verification system has been amended. By the results of the experimental data show that:after RBF neural network calibration good approximation to the true value of liquid level height.Put forward and set up to five degrees of freedom dynamic model of liquid level measurement system, deduced mathematical model of dynamic response, on this basis, the finite element analysis software ANSYS modal analysis is carried out on the system, and calculate the system5order natural frequency and vibration patterns, the key components of the detection system also has carried on the analysis and verification of the stress and strain. For vibration interference problems of the detection device by external systemic, analyze the vibration and vibration reduction processing, and computer simulation analysis are carried out using MatLAB software.The main components of the liquid level measurement system have been built and analysis. Systemic vibration has been analysis and damping.The simulation analysis for vibration by using Matlab.Level measurement system needs to be fast, accurate positioning and presence of vibration and other interference factors specific circumstances, the use of zero-zero phase difference tracking control (ZPETC) and the disturbance observer (DOB) combined tracking robust control as the inspection system of linear motor control strategy. Can effectively reduce the tracking error, and to improve the accuracy of the movement. The disturbance observer allows the system has a strong interference suppression capability and meets the robustness requirements, so that the level detection process can be more stable and effective working time.LabVIEW virtual instrument technology, the development of the system’s control software, system software acquisition and exercise joint control, to ensure the accuracy of the signal acquisition and analysis software, real-time computing, graphics and digital two forms display level and sedimentation rate situation. The software system also can complete alarm information storage, printing and other functions.The accuracy of the system has been experimental. The main factor of system errors has been analysis. The precision experiments show:absolute measurement accuracy and repeatability of measurement accuracy of the system in less than10μm, the relative error does not exceed0.3%, to meet the requirements of the the salt spray sedimentation rate level measurement accuracy. Experimental studies to prove the feasibility of fog deposition rates level measurement system, advanced reliability and practicality.更多还原