浅水湿法FCAW焊缝成形自动控制研究

发布时间：2018-05-19 07:02

本文选题：湿法焊接 + 药芯焊丝电弧焊　；参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：水下焊接是海洋工业和水下结构建造维修的关键技术之一,随着对深海资源开发利用的需要愈发迫切,对水下焊接提出了更高要求。湿法焊接是目前应用最广泛的水下焊接技术,在控制成本、环境适应性、设备操作灵活性等方面具备优势。然而目前水下湿法焊接多由潜水焊工手动完成,焊接效率低,焊缝质量难以保证。自动化是工程建设制造领域的发展方向,湿法焊接与自动化技术的结合是提高水下焊接质量和工作效率的重要方法,发展前景广阔。药芯焊丝焊接(FCAW)是水下湿法焊接自动化发展的重要方向,本文通过建立湿法FCAW水下焊接试验平台,实现了焊接电信号和图像信息的实时采集存储,以及湿法焊接过程参数的计算机自动控制。在此基础上,设计了电信号软件处理程序,对采集到的电压电流信号进行了软件滤波处理及统计分析处理,提取了反映焊接过程质量的信号特征参数,为焊接质量监控、焊接稳定性分析提供了电信号信息依据。利用激光光源开发了水下湿法焊接主动视觉传感系统,并开发了相应的图像处理算法,实现了对焊缝成形特征值的提取。焊缝成形效果是衡量焊接接头质量的重要标准,本文通过湿法FCAW焊接试验,对浅水环境下湿法FCAW焊缝成形的影响因素进行了研究。在此基础上,分析了焊缝成形与焊接过程稳定性的关系,建立了焊接工艺参数与焊缝熔宽、余高值关系的一次回归、二次回归和指数回归模型,通过模型拟合程度的统计学分析,发现指数模型标准残差值小,拟合程度高,适用于焊缝成形控制中。为改善湿法FCAW焊缝成形效果,进行了PID控制和模糊控制系统仿真,根据仿真结果设计模糊控制程序,建立了焊缝熔宽闭环控制系统,并进行了高度方向变化控制试验和电压变化控制试验。从电信号波形分析和试验结果来看,湿法FCAW焊接控制系统有效提高了焊接过程稳定性,调节速度快,消除了咬边、夹渣、焊瘤等焊接缺陷,焊缝成形波动性减弱,熔宽稳定系数提高了100%以上,在改善焊缝成形质量方面有显著效果。
[Abstract]:Underwater welding is one of the key technologies in the construction and maintenance of marine industry and underwater structures. With the development and utilization of deep-sea resources becoming more and more urgent, higher requirements for underwater welding have been put forward. Wet welding is the most widely used underwater welding technology, which has advantages in cost control, environmental adaptability, equipment operation flexibility and so on. However, the underwater wet welding is mostly accomplished by the submersible welder manually, the welding efficiency is low and the welding quality is difficult to guarantee. Automation is the development direction in the field of engineering construction and manufacturing. The combination of wet welding and automation technology is an important method to improve the quality and working efficiency of underwater welding. Flux-cored wire welding (FCAW) is an important direction of underwater wet welding automation. In this paper, the real-time acquisition and storage of welding electrical signals and image information are realized by establishing a wet FCAW underwater welding test platform. And the automatic control of the parameters of wet welding process by computer. On this basis, the software processing program of electric signal is designed, and the voltage and current signal collected is processed by software filtering and statistical analysis, and the characteristic parameters of signal reflecting the quality of welding process are extracted, which is the monitoring of welding quality. The analysis of welding stability provides the information basis of electric signal. The active vision sensing system of underwater wet welding is developed by using laser light source, and the corresponding image processing algorithm is developed to extract the characteristic value of weld formation. The effect of weld forming is an important standard to evaluate the quality of welded joints. In this paper, the influencing factors of wet FCAW welding in shallow water environment are studied by means of wet FCAW welding test. On this basis, the relationship between weld forming and welding process stability is analyzed, and the primary regression, quadratic regression and exponential regression model of the relationship between welding process parameters and weld width and residual height are established. Through the statistical analysis of the fitting degree of the model, it is found that the standard residual value of the exponential model is small and the fitting degree is high, which is suitable for weld forming control. In order to improve the weld forming effect of wet FCAW, the simulation of PID control and fuzzy control system is carried out. According to the simulation results, the fuzzy control program is designed, and the closed loop control system of weld width is established. The height direction change control test and voltage change control test are also carried out. From the waveform analysis and test results, the wet FCAW welding control system can effectively improve the stability of the welding process, adjust the speed quickly, eliminate the welding defects, such as edge cutting, slag inclusion, welding nodule, etc, and weaken the fluctuation of weld formation. The stability coefficient of weld width is increased by more than 100%, and it has remarkable effect in improving the quality of weld forming.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG409

【引证文献】