【作者】 朱小虎；

【导师】 张涛；

【作者基本信息】 中南大学 ， 控制科学与工程， 2011， 硕士

【摘要】 埋弧焊焊接过程的控制是焊接领域内一个重要课题。由于电弧的非线性以及现场条件的复杂干扰,使得对埋弧焊焊接过程的控制存在较大的难度,控制效果难以达到要求。针对现有的控制器适应性和鲁棒性不高的问题,论文对埋弧焊的焊接过程进行了分析,并对其控制方法进行了研究。主要内容有：埋弧焊焊接过程分析。首先对埋弧焊焊接过程进行了分析,在对焊接过程的各个子模块进行详细研究的基础上,得到了埋弧焊的数学模型。并且分析了可变外特性埋弧焊系统中的两个子系统：等速送丝埋弧焊系统和变速送丝埋弧焊系统。埋弧焊系统的线性化。对常用的线性化方法做了分析,并采用基于微分几何的精确反馈线性化方法对埋弧焊系统进行了处理,得到了其线性化的数学模型。埋弧焊系统的滑模变结构控制。对滑模变结构控制理论进行了研究,针对得到的线性化埋弧焊数学模型,设计了变速送丝埋弧焊的滑模控制器。并且利用MATLAB搭建了仿真模型。仿真结果表明,设计的控制器能够达到控制要求,在出现干扰的情况下,弧长能够很快恢复。可变外特性埋弧焊系统实现。分析了系统的弧焊电源主电路、控制电路及送丝系统等各个部分。并且给出了控制系统的软件框图,通过软件实现滑模变结构控制算法。更多还原

【Abstract】 In welding field, control for the process of submerged arc welding is an important subject. Because of the nonlinear of arc and complex disturbances in field conditions, it’s difficult to control and meet the requirements. For the low adaptability and robustness of existing controllers, this paper analyzes the weld process of submerged arc welding and has a research on the control methods. The main contents of this paper are:An analysis is conducted on the submerged arc welding process. First, a detail study is given to every module of submerged arc welding process. Then, the model of the submerged arc welding is obtained based on the mathematical model of these sub-modules. And the changeable external characteristic of submerged arc welding system which contains two subsystems is studied. The two subsystems are the submerged arc welding system with constant wire feed speed and the one with variable wire feed speed are construed.Linearization of the non-linear submerged arc welding models is carried. First, the common meatheads of linearization are analyzed and the accurate feedback linearization based on differential geometry is chosen. According to this meathead, the non-linear model of submerged arc welding is converted to linear model.The sliding model controller for submerged arc welding is designed. First, the theory of sliding model control is studied. Then, the sliding model controller is planed for the linear model, which is converted from the submerged arc welding with variable wire feed speed. And then, the simulation models are set up on the platform of the MATLAB. The results show that the designed controller can commendably achieve the requirement. In the case of disturbance, the length of arc recovers quickly.The control system on submerged arc welding with changeable characteristics is realized. First, the main circuit of arc welding power is studied and designed. The control circuit and wire feed system are also analyzed. Then, the software charts are shown and the arithmetic of sliding mode control is realized.更多还原