导　　师： 黄石生

学科专业： 080503

授予学位： 博士

作　　者： ;

机构地区： 华南理工大学

摘　　要： 机器人双丝共熔池脉冲MAG高速焊技术集高效优质和自动化于一体，愈来愈受到重视，已成为国内外焊接领域的研究热点，但是国内的相关研究起步相对较晚，并且还不能批量生产这种机器人双丝焊装备。本论文在黄石生教授主持的国家自然科学基金项目（No.50375054）和广东省科技计划项目/(No.2010B010900027/)资助下，在理论分析的基础上，结合数字化控制技术和数字通信技术，建立了基于焊接机器人的双丝共熔池脉冲MAG高速焊装备试验平台，并对其特性和应用进行了深入研究。 论文在对相关理论问题分析的基础上建立了基于焊接机器人的双丝共熔池脉冲MAG高速焊的动态过程数学模型，在此基础上全面模拟、深入分析了双丝脉冲MAG高速焊的动态过程，进行了电弧熔滴过渡的稳定性仿真、弧长和干伸长的抗扰性仿真、电弧动态调节仿真及系统改进分析，认为电弧的熔滴过渡与弧焊电源的时间常数有着非常密切的关系，但对焊丝干伸长没有明显影响；弧长扰动与焊丝干伸长扰动是两种完全不同性质的扰动：焊丝干伸长扰动后，系统恢复到原来的稳定工作点；而弧长扰动却使系统稳定到一个新的工作点，新工作点是靠干伸长变化补偿弧长的变化而形成的稳定工作状态，但这种补偿作用却不能完全抵消掉弧长的变化量而使系统恢复回原来的工作点。 设计了基于焊接机器人的双丝共熔池脉冲MAG高速焊装备试验平台方案，在充分分析研究ABB机器人的结构基础上进行了机器人双丝MAG焊平台人机接口的设计，采用C//OS-II嵌入式操作系统及高性能MCU C8051F020，并对C//OS-II嵌入式操作系统的移植和任务划分进行了研究，讨论了各任务之间的通信与同步问题。 设计并实现了双丝脉冲MAG焊双弧焊电源和双送丝机之间的数字通信系统，软件模块化设计精巧，新颖的二次握手和双重标识机制的新通信协议机制，使得数据标识的发送、接收避免了时序的混乱，双机通信准确、快速、可靠，并可以快速地进行错误的纠正，保证了数据的正确传输,试验表明该通信系统可靠实用,经过改进也可用于多丝焊的通信； 深入研究了双丝共熔池脉冲MAG高速焊接过程协同控制模式下熔滴过渡的关键问题，利用高速摄影仪和小波分析仪进行了双丝脉冲MAG焊接过程送丝速度、电流频率、双丝脉冲相位对熔滴过渡及焊缝成形影响的高速摄影和小波分析；并应用具有自由表面的流体稳定性理论，分析了双电弧共熔池脉冲MAG焊前丝、后丝脉冲电流相位关系对焊缝成形质量的影响，认为双丝焊在同步相位控制模式下，双电弧同时燃弧使熔池拉长是造成熔池失稳、并最终形成驼峰焊道的主要原因； 利用建立的计算机测试平台对基于焊接机器人的双丝共熔池脉冲MAG高速焊装备进行了大量的工艺试验，并进行了全面的双丝协同控制测试，结合本文对双丝焊熔滴过渡的研究认为，总体上前后和后丝交替相位协同控制模式焊接效果要比随机模式好，而随机模式要好于同步模式，主要表现在交替相位控制模式飞溅、噪音少一些而同步模式多一些，但适当增加脉冲频率会提高焊缝的成形质量；随机模式介于两者之间。总体上脉冲频率高些会使电弧挺度增强，焊缝成形质量会好一些。但是根据规范不同，过高的脉冲频率却降低焊缝成形质量。设定主机的电流规范大一点，电弧电压要与从机相同或比从机低一些，这样的焊接规范电弧挺度比较好，而从机电弧由于磁偏吹有些向主机电弧倾斜，试验证明这种电弧形态配合对焊缝成形有利。 Robot twin-wire co-pool pulsed MAG high-speed welding /(robot TCGMAW/) technologypossesses the advantages of high efficiency, quality and automatization, and is paid muchmore attention nowadays; it has become the research focus in the welding field. Nevertheless,our country’s research on it commences late and can’t produce this kind of robot twin-wirewelding equipment in batch production. Under the foundation of National Natural ScienceFoundation of China /(No.50375054/) and the Project of Guangdong Province Science andTechnology Plan /(No.2010B010900027/), on the basic of theory analysis, based on thetechnology of digital control and digital communication, this paper presents a thoroughresearch on robot TCGMAW and TCGMAW’s droplet transfer and welding seam on differentwire feeding speed, pulse frequency and phases. In this paper with TCGMAW based on the welding robot and numerical synergic controlsystem built with C//OS-II embedded operationg system, the modern computercommunication system between the twin power sources and the wire feeders was designedand implemented which decreased the quantity of communication data wires between the twinpower sources and the wire feeders, reduced the probability of failure, increase theproductivity. The mathematical model of TCGMAW dynamic process based on the welding robot wasestablished, based on it the TCGMAW dynamic process was simulated and analysed;considered that there was intimate relation between droplet transfer and time constant of arcwelding power source, but there was no evident effect on wire extension; after wire extensionturbulencd system recovered to its original stable working point; but arc lenth turbulencemade the system stable into a new working point. The key probems under synergic control in TCGMAW were researched, by the high-speedcamera and the wavelet analysis instrument, the effects on TCGMAW’s droplet transfer andwelding seam on different wire feeding speed, pulse frequency and phases were analyzed. Using the theory of fluid stability the effect of TCGMAW’s pulse phases relation of frontwire and back wire to welding formation was explained, considered that under the mode ofsynchronized phase control the main reason of welding pool instability and formatting finalhumping bead was the twin wires causing the welding pool elongated. The synergic control was tested with TCGMAW based on the welding robot computertesting platform; the over-all tests under twin-wire synergic control were accomplished.Combined with the research of twin-wire droplet transfer in this paper, considered that under alternate pulse phase the welding result was better than that under random pulse phase, andthe welding result under random pulse phase was better than that under synchronized pulsephase. On the whole high pulse frequency enhanced the arc stiffness and thereby made thewelding seam better, but over-high pulse frequency decreased welding seam quality. The study on TCGMAG based on the welding robot and behavior of droplet transfer undersynergic control in this paper will provide theoretical and practical fundamental evidence andreference.

关 键 词： 双丝共熔池脉冲 高速焊 数字通信 协同控制 熔滴过渡 高速摄影

分 类 号： [TG444]

领　　域： [金属学及工艺]