【作者】 肖宏；

【导师】 樊丁； 石玗；

【作者基本信息】 兰州理工大学 ， 材料加工工程， 2011， 硕士

【摘要】 焊接温度是影响高频焊管焊缝韧性最重要的因素之一,焊接温度在高频焊管的生产过程受到管材材质壁厚不均、焊接速度波动等一些因素影响容易发生波动,焊接温度的波动最终会导致高频焊管焊缝成型质量的下降。本文对如何对高频焊管焊接温度进行监测控制并应用于生产实际做了研究。试验前期根据高频焊管温度控制模型,使用Matlab的Simulink仿真工具包进行了高频焊管温度控制仿真试验。分别设计了常规PID控制器和模糊自适应PID控制器,比较了两种控制器的仿真控制效果。试验结果表明:在添加干扰信号的模型条件下,常规PID控制器和模糊自适应PID控制器都能有较好的控制精度和响应速度,常规PID控制器响应速度要稍快于模糊自适应控制器,模糊自适应PID控制器具有较小超调量,两种控制器有各自优点。在仿真的基础上,结合高频焊管现场生产状况对控制方案进行了分析选择。由于高频焊管是个高速的生产过程,在焊管生产现场,模糊PID控制方案较常规PID控制方案调整参数多、周期长,调整不适很容易造成很高的废管率,因而最终选择常规PID控制器设计了基于labview平台的高频焊管温度监控系统。试验结果表明:该系统具有良好的测温精度和控制响应速度,能及时准确显示采集到的焊管温度,在测温准确的前提下,可以对焊管温度起到较好的控制效果。为了满足企业的生产要求,构建了基于PLC和触摸屏的高频焊管温控系统。PLC和触摸屏系统相对微机系统而言,具有更高的可靠性,操作简单,更方便工人在高频焊管生产车间进行现场操作使用。现场试验证明,PLC和触摸屏系统可以准确显示采集到的高频焊管温度趋势图,在焊管位置波动不大,测温准确的前提下能有很好的温度控制效果。试验后期设计了高频焊管温度视觉综合监测系统,通过对焊管焊接区域温度和视觉的综合监测,可以更加全面的对焊管生产质量进行监测分析。对高频焊管焊接加热区域的图像特征提取进行了算法研究。研究表明,使用形态学算子能够准确提取出高频焊管加热区域的图像边缘,提取的图像边缘信息光滑、连续、断点和噪声较小。在提取焊管加热区图像的基础上,研究了加热区宽度值提取算法,对视觉检测过程中采集的每帧图像在同一位置进行了焊管加热区宽度提取计算,分析了熔宽变化和焊接缺陷之间的对应关系。更多还原

【Abstract】 There are many factors to affect the toughness of weld beads for high-frequency welded pipe.Welding temperature is one of the most important factors. Welding temperature in high frequency welded pipe production process will flutuate due to the influence of the thickness of pipe wall and the fluctuation of welding speed. The fluctuation of welding tempreture can eventually lead quality of the welding seam forming to decline. The researches were done that how to monitor and control the welding temperature of high frequency welded pipe and use it in this paper .In the earlier stage of test, select temperature control models of high frequency welded pipe, and use Simulation Tookit of matlab to do simulation and control of temperature for high frequency welded pipe . General PID controller and fuzzy adaptive PID controller are designed separately, then the two simulation of controller’s results are compared. Test results show that both the conventional PID controller and the fuzzy adaptive PID controller can have a good control precision and response speed in the condition of adding interference signal to the model, the conventional PID controller response speed slightly faster than fuzzy adaptive controller, but the fuzzy adaptive PID controller has small overshoots, two controllers have their respective advantages.On the basis of simulation,combine with production status of high frequency welded pipe to anlayze and choose.Due to the production process of high frequency welded pipe having high speed, in manufacturing sites, fuzzy PID control has more regulation parameters and longer life cycle than general PID control. Adjustment discomfort easily lead to a high rate of waste pipes. Finally select the general desigh of PID controller to design temperature monitoring system of high frequency welded pipe based on Labview platform . The results showed that: this system had a good measurement accuracy and response speed, and accurately display collected welded pipe temperature. Besides, on the premise of temperature measurement accuracy, it well control welded pipe temperature.Temperature control system of high frequency welded pipe based on PLC and touch screem was was built on the basis of microcomputer high frequency welded pipe. The system of PLC and touch screem has a higher reliability ,easy operation, more convenience for workers in high-frequency welded pipe peoduction shop to operate on the spot. Field test probe that: PLC and touch-screem system can accutately display a trend diagram of collected temperature for high-frequency welded pipe. On the condition that little fluctuatio of pipe location and accuracy of emperature measurement, it well control the temperature.Aimed at environmental complex of high frequency welded pipe production and many factors leading to the instability of temprature measured, the visual monitoring system of high frequency welded pipe temperature was designed. The purpose is that through the comprehensive monitoring of welded pipe welding temperature and visual, the quality of welded pipe production was comprehensively monitored and analyzed. The image feature extraction of the high frequency welded pipe welding heating area algorithm was in study . Research shows that the use of morphological operator can accurately extract the image edge of heating area of high frequency welded pipe, the extracted image edge is smooth, continuous, breakpoint and noise is small. Based on the extracted image of heating area, width values extraction algorithm of the heating area is studied: the width extraction of the welded pipe heating area calculation is carried out for every frame image of collected visual inspection process in the same position, the corresponding relationship of width changes and the welding flaws is analysed.更多还原