刘锋 高忠林 路向琨 翟宝亮 徐昊

摘要：针对点焊过程中伺服焊钳的重复定位精度差、速度响应慢等问题，利用伺服焊钳电机模型，采用分数阶低通 IMC 滤波器，建立基于 CRONE 原理的分数阶 PID 参数整定模型，设计一种基于内模控制的直流伺服电机的分数阶控制器，可以提高伺服焊钳控制的稳定性和精确性。通过仿真对控制系统进行阶跃响应测试、跟踪性能测试以及模型不匹配时适用性测试，仿真结果表明，该控制器跟踪精度高、响应速度快、调速范围宽、低速稳定性好，适用性好，比传统分数阶 PID 设计的控制器表现更加优异，验证该控制器的有效性。同时，由于采用 CRONE 原理进行分数阶 PID 控制器参数整定，只需要2个调节参数，大大简化参数整定过程。

关键词：伺服焊钳;内模控制; CRONE 原理;分数阶 PID

中图分类号： TP273文献标志码： A文章编号：1674–5124（2021）12–0114–06

Fractional servo welding tongs control based on internal model control

LIU Feng，GAO Zhonglin，LU Xiangkun，ZHAI Baoliang，XU Hao

（Tianjin 707 Hi-tech Co.， Ltd.， Tianjin 300131， China）

Abstract： Aiming at the problems of poor repetitive positioning accuracy and slow speed response of the servo welding gun during the spot welding process， using the servo welding gun motor model and using a fractional low-pass IMC filter， a fractional PID parameter tuning model based on the principle of CRONE is established. Afractional-ordercontrollerof DCservomotor basedoninternalmodelcontrolisdesigned，whichcan improve the stability and accuracy of servo welding gun control. Step response test， tracking performance test， and suitability test when the model does not match are performed on the control system through simulation. The simulation results show that the controller has high tracking accuracy， fast response speed， wide speed range， good low-speed stability， and good applicability. It performs better than the traditional fractional PID design controller， which verifies the effectiveness of the controller. At the same time， because the CRONE principle is used for the parameter tuning of the fractional PID controller， only two adjustment parameters are needed， which greatly simplifies the parameter tuning process.

Keywords： servo welding tongs; internal model control; CRONE principle; fractional PID

0引言

电阻点焊在焊接领域中具备应用技术成熟、机械自动化效率高、成本低廉等优点，已广泛应用于电阻点焊在焊接领域中具备应用技术成熟、机航空、航天、汽车等工业领域。电阻点焊质量是由电、热、力等复杂因素共同决定的，除了焊接过程中焊接参数的调优，提高伺服焊钳控制精度对点焊质量的提高也具有重要作用，赵回等[1]运用LuGre摩擦模型和非线性干扰观测器补偿非线性干扰，提高了伺服系统的跟踪性能;杨瑞峰等[2]运用基于 Backstepping 控制、前馈控制和等价输入干扰（equivalent input disturbance， EID）估计的鲁棒抗扰控制策略提高了 PMSM 位置伺服系统动态跟踪特性和抗干扰特性。……