Abstract:  Most of the existing friction stir welding equipment lacked effective monitoring of processing variables. The establishment of an open control system was an effective means to solve this problem. However， there were two major differences between the friction stir welding processes and the traditional metal cutting processes， namely the welding inclination and arc tangent tracking functions. Existing equipment integrated the arc tangent tracking function into the control system， which led users to special design for this function if they studied open controllable systems， which in turn led to longer equipment development cycles and to increase costs. An open control system was built based on Ether CAT， and then a gantry type friction stir welding machine (tool) was taken as an example， the D-H method was used to derive the machine (tool) full-parameter forward and reverse kinematics mathematical model， and a simple plane the two-dimensional arc tangent tracking method was proposed， which might complete friction stir welding without studying the three-axis interpolation algorithm on the basis of the existing two-axis arc interpolation. Finally， a typical welding seam trajectory was selected for motion simulations and welding tests， which verified the correctness of the parameterized kinematics model of the machine (tool) and the feasibility of the arc tangent tracking method. 

Key words:  , friction stir welding machine, kinematic model, D-H method, tangent tracking, motion simulation

摘要： 现有大部分搅拌摩擦焊设备缺乏对过程变量的有效监控，建立开放式的控制系统是解决这一问题的有效手段，然而搅拌摩擦焊工艺与传统的金属切削有两大不同，即焊接倾角与圆弧切线跟踪功能。现有设备将圆弧切线跟踪功能集成到控制系统中，导致用户研究开放式可控制系统时还需对此功能进行专门的设计，进而导致设备研发周期变长、成本增加。构建了基于Ether CAT的开放式控制系统，以一种龙门式搅拌摩擦焊机床为例，运用D-H法推导出机床全参数化正逆向运动学数学模型，并提出一种简单的平面二维圆弧切线跟踪方法，在已有两轴圆弧插补的基础上不需研究三轴插补算法即可完成搅拌摩擦焊。最后选择一种典型的焊缝轨迹进行运动仿真与焊接试验，验证了机床参数化运动学模型的正确性及圆弧切线跟踪方法的可行性。

关键词: 搅拌摩擦焊机床, 运动学模型, D-H法, 切线跟踪, 运动仿真