【作者】 晋连志；

【导师】 高洪明；

【作者基本信息】 哈尔滨工业大学 ， 材料加工工程， 2007， 硕士

【摘要】 焊缝跟踪传感技术在焊接自动化生产中具有非常重要的作用,它是保证焊缝质量的关键。目前常用的传感方式如视觉传感和电弧传感等,都存在各自的局限性。基于微束等离子弧的焊缝跟踪传感技术是焊缝跟踪领域的一个创新,它相对于传统传感方式具有一些独特的优点。本文根据其传感原理,通过设计微束等离子弧传感器等工作,搭建起一套合适的引弧装置和相应的硬件平台,产生了可供试验测量用的稳定的等离子电弧。针对该等离子弧系统,开发了与之配套的电压信号采集、分析软硬件系统。信号采集模块中,根据采集卡提供的接口,实现了高频率、大数据量采集,波形图实时显示和二进制或十进制数据同步保存;分析模块中,实现了数字滤波及其他一些数据分析功能。通过静态试验,获得了等离子弧长度与测量电压之间的基本变化趋势和特点,并深入解释了电弧的五个工作状态——极限期、工作区Ⅰ、过渡区、工作区Ⅱ和导通期以及它们的形成原因;全面分析了各影响因素对传感过程可能造成的影响,其中维弧电流、离子气流量等因素对于输出电压起到决定性的作用;通过静态、动态试验等总结出适合本文硬件设备的一套最佳参数,并对微束等离子发生器进行了相应的改进,使电弧达到了更加稳定的状态。在电弧传感器及其低层处理获取的接头表面轮廓基础上,通过多线段拟合的近似算法进行了典型焊接接头类型的识别和特征参数的提取等工作。更多还原

【Abstract】 Weld seam tracking and sensing technology plays a very important role in welding automate production and is also a critical factor in weld seam quality. The most common sensing methods till now are vision sensor, tactile sensor and arc sensor, etc. But they all have limitations respectively. The technology of weld seam tracking based on micro plasma arc has some particular merits comparing with traditional tracking means and also is an innovation in seam tracking field. According to the principle of this seam tracking method, a suitable system which can generate non-transferred arc was built by designing a micro plasma arc sensor, an arc generating device and some corresponding equipments.A corresponding signal collection and analysis system was developed. In the signal collection module, the collection of high frequency and large numbers of data was realized. Also, oscillogram show and binary or decimal data saving real-time were actualized. In the signal analysis module, digital filter and some other analysis functions were realized.Through static experiments, changing trend and other properties of arc-length to voltage curve was concluded and explained, then further experiments were carried out to analyse all the influence factors. Among which non-transferred arc current and plasma gas flow were regarded as the main factors to the output. By a series of experiments, the most optimum parameters were concluded. After a summing-up of the foregoing work and results, a steadier arc was produced by making an improvement on the micro plasma arc sensor.Afterwards, by the method of multi-line segments fitting, the work of identification of the joints type and pick-up of the characteristic parameters was performed.更多还原