Design and Motion Control of the High Precision Heavy Load Friction Stir Welding Robot
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摘要: 针对高强度大型复杂曲面零件的高精度搅拌摩擦焊需求，研制开发了一种重载搅拌摩擦焊（friction stir welding，FSW）机器人．为使机器人具有大工作空间与灵巧作业能力，选择串联机构作为机器人构型，并阐述了高精度重载机构的设计与刚度校核方法．推导了腕关节含间隙的动力学模型，提出了双电机消隙控制方法，并对不同负载与偏置电流下的消隙效果进行了仿真分析，结果显示主动消隙方法能有效抑制传动间隙造成的位置波动与误差．为消除z轴在自重与焊接力作用下的挠度变形，提出了一种挠度主动补偿方法，构建了动力学模型与控制策略，仿真结果显示挠度补偿系统能快速有效地抑制挠度造成的轨迹误差．FSW机器人样机焊接实验表明，所提出的机器人在重载作业中能实现高精度的轨迹控制．Abstract: To meet the high precision demand of friction stir welding (FSW) for high strength large parts with complex surface,a heavy load FSW robot is developed. In order to make the robot have large working space and dexterous operation ability, the serial mechanism is chosen as the robot configuration, and the design and stiffness checking method of the high precision mechanism under heavy load are elaborated. Dynamic model of the wrist joint with clearance is deduced, and the dual motor backlash elimination control method is proposed. Backlash elimination effect simulations for different loads and bias currents are carried out, and the results show that the active backlash elimination method can effectively suppress the position fluctuation and error caused by the transmission backlash. Furthermore, in order to eliminate the deflection deformation of the z axis under the action of self weight and welding force, a deflection active compensation method is proposed, and the dynamic model and control strategy are constructed. The simulation results show that the trajectory errors caused by deflection deformation can be quickly and effectively suppressed by the deflection compensation system. The FSW robot prototype experiment shows that the robot can realize high precision trajectory control under heavy load.
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[1] Gibson B T, Lammlein D H, Prater T J, et al. Friction stir welding:Process, automation, and control[J]. Journal of Manufacturing Processes, 2014, 16(1):56-73.
[2] Mendes N, Neto P, Loureiro A, et al. Machines and control systems for friction stir welding:A review[J]. Materials & Design, 2016, 90(15):256-265.
[3] Zhao X, Kalya P, Landers R G, et al. Design and implementation of nonlinear force controllers for friction stir welding processes[J]. Journal of Manufacturing Science and Engineering of the ASME, 2008, 130(6):No.061011.
[4] de Backer J, Bolmsjo G. Deflection model for robotic friction stir welding[J]. Industrial Robot, 2014, 41(4):365-372.
[5] Guillo M, Dubourg L. Impact & improvement of tool deviation in friction stir welding:Weld quality & real-time compensation on an industrial robot[J]. Robotics and Computer-Integrated Manufacturing, 2016, 39(5):22-31.
[6] Longhurst W R, Strauss A M, Cook G E. Enabling automation of friction stir welding:The modulation of weld seam input energy by traverse speed force control[J]. ASME Transactions on Journal of Dynamic Systems Measurement and Control, 2010, 132(4):041002-1-041002-11.
[7] Qin J N, Leonard F, Abba G. Real-time trajectory compensation in robotic friction stir welding using state estimators[J]. IEEE Transactions on Control Systems Technology, 2016, 24(6):2207-2214.
[8] Davis T A, Shin Y C, Yao B. Observer-based adaptive robust control of friction stir welding axial force[J]. IEEE/ASME Transactions on Mechatronics, 2011, 16(6):1032-1039.
[9] Zirn O, Fink A. Multidrive control for milling rotary tables with flexible reduction stages[C]//IEEE International Conference on Power Engineering. Piscataway, USA:IEEE, 2009:402-407.
[10] Zirn O,Hoos A, Loth M, et al. Multidrive control for machine tool servo axes[C]//4th IET Conference on Power Electronics, Machines and Drives. London, UK:IET, 2008:164-168.
[11] 任海鹏,何斌. 双电机驱动机床进给系统消隙控制[J]. 电机与控制学报,2014,18(3):60-66. Ren H P, He B. Anti-backlash control of machine tool feed system driven by dual-motors[J]. Electric Machines and Control, 2014, 18(3):60-66.
[12] Yeh T J, Wu F K. Modeling and robust control of worm-gear driven systems[J]. Simulation Modelling Practice and Theory, 2015, 17(5):767-777.
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