焊缝位姿跟踪的多轴耦合控制研究

发布时间：2018-05-07 07:57

本文选题：焊缝位姿跟踪 + 轮廓误差　；参考：《南昌航空大学》2017年硕士论文

【摘要】：在实际焊接过程中,因为各类不定因素的影响,导致焊接轨迹偏离焊缝,即形成焊缝偏差,从而对焊接质量产生影响。焊缝跟踪作为焊接自动化领域一项具有关键意义的技术,就是针对这个问题通过优化系统设备实现实时提取轨迹偏差并调节焊接轨迹。通常焊缝跟踪过程中,各轴根据各自偏差进行调节,可以很好地解决单轴的跟踪精度,然而焊缝位姿跟踪是多轴协调控制的结果,每个调节轴的跟踪误差不协调会直接体现到焊缝轮廓上。因此进一步研究以轮廓误差作为控制目标的焊缝位姿跟踪对提高焊接自动化水平有着重要意义。本文针对基于复合传感技术的GTAW过程,进行焊缝位姿跟踪的多轴耦合控制研究。设计了一套由被动视觉传感器和弧压传感器组成的复合传感系统实时获取全面可靠、清晰稳定的焊缝特征信息,及其对应的一套完整的图像和弧压信息的处理算法提取焊缝位姿偏差。另外基于固高平台设计了一套焊缝位姿调节系统及相关焊接件夹具。最后在Visual C++软件系统环境下采用多线程技术开发了一套焊缝跟踪系统软件,实现包含纵向、竖向位置及焊枪行走角的姿态的焊缝位姿的跟踪。首先针对焊缝跟踪系统的误差来源进行分析之后,建立了只有平动轴的焊缝位置跟踪和带转动轴的焊缝位姿跟踪情况下的轮廓误差计算模型。设计了一套针对轮廓误差的多轴耦合控制的焊缝位姿跟踪系统,由于轮廓误差不能直接进行控制,所以提出了相应的焊缝跟踪误差补偿量的成比例分配模型。此外设计了一套Fuzzy-P控制器,并通过MATLAB仿真试验验证其具有优良的性能。最后对两平动轴和带转动轴两种情况分别基于所开发的系统软件进行优化,得到含多轴耦合控制的焊缝位姿跟踪的系统软件。为验证焊缝跟踪系统及多轴耦合控制系统的实效性,分别利用有无所设计的多轴耦合控制系统在GTAW焊缝位姿跟踪系统进行薄板对接跟踪试验对比。试验结果表明,设计的焊缝位姿跟踪系统能够有效保证焊接质量,多轴耦合控制系统的应用使得焊缝位姿跟踪精度得到稳定提高,达到预期目标。
[Abstract]:In the actual welding process, because of the influence of various uncertain factors, the welding track deviates from the weld seam, that is, the welding seam deviation is formed, which has an effect on the welding quality. As a key technology in the field of welding automation, welding seam tracking is aimed at this problem by optimizing system equipment to achieve real-time extraction of trajectory deviation and adjustment of welding trajectory. In the process of welding seam tracking, each axis can be adjusted according to its own deviation, which can solve the tracking accuracy of single axis well. However, position and attitude tracking of weld seam is the result of multi-axis coordinated control. The tracking error of each adjusting shaft is not coordinated directly to the weld profile. Therefore, it is important to further study the seam position and pose tracking with contour error as the control target to improve the level of welding automation. In this paper, multiaxial coupling control of position and attitude tracking of weld seam is studied for GTAW process based on composite sensing technology. A complex sensing system composed of passive vision sensor and arc pressure sensor is designed to obtain comprehensive, reliable, clear and stable weld seam characteristic information in real time. A complete set of image and arc voltage information processing algorithm is used to extract the position and attitude deviation of weld seam. In addition, a welding position adjustment system and related welding fixture are designed based on the fixed height platform. Finally, a set of weld seam tracking system software is developed by using multithreading technology in Visual C software environment, which can track the position and attitude of weld seam including longitudinal, vertical position and welding torch walking angle. After analyzing the error source of the weld tracking system, the calculation model of the contour error is established under the condition of the position tracking of the weld with the translational shaft and the tracking of the position and orientation of the weld with the rotating shaft. A welding seam position and attitude tracking system based on multi-axis coupling control for contour error is designed. Because contour error can not be controlled directly, a proportional distribution model of compensation amount for seam tracking error is proposed. In addition, a set of Fuzzy-P controller is designed, and its excellent performance is verified by MATLAB simulation. Finally, based on the developed system software, the system software for position and attitude tracking of weld seam with multi-axis coupling control is obtained. In order to verify the effectiveness of the weld seam tracking system and the multiaxial coupling control system, the tracking experiments of thin plate docking were carried out by using the multi-axis coupling control system designed in GTAW welding seam position and attitude tracking system. The experimental results show that the welding seam position and attitude tracking system can effectively guarantee the welding quality, and the application of multi-axis coupling control system can improve the precision of position and attitude tracking steadily and achieve the desired goal.
【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG409

【参考文献】