力控法兰的模糊PID恒力控制方法

针对工业机器人进行接触式作业过程中对末端接触力的要求,提出了一种基于力控法兰的末端恒力控制方法。对力控法兰进行了分析建模与参数辨识,设计了模糊控制与比例积分微分(proportion integral derivative,简称PID)控制并行的模糊PID控制器,通过Matlab仿真对纯模糊控制与模糊PID控制效果进行了对比,并研究了模糊PID控制器各参数对控制性能的影响。最后,搭建了基于Labview和外部设备互连(peripheral component interconnect,简称PCI)总线数据采集卡的实验平台,对力控法兰末端输出力进行了实验验证。仿真结果表明,纯模糊控制可提高系统响应性能,但存在一定的稳态误差。加入PID控制与模糊控制并行控制后,仿真与实验证明,阶跃响应的稳态误差消除,正弦跟随效果明显改善,恒力控制输出力在期望力F=10N时波动误差为±0.8N。因此,通过模糊PID控制可实现力控法兰末端的恒力控制,具有较好的动态响应性和跟随鲁棒性。

Fuzzy Proportion Integral Derivative Constant Force Control Method of Force-Controlled Flange

In order to meet the requirements of end contact force for industrial robot during contact operation,a constant force control method is proposed based on force-controlled flange. The analysis, modeling and parameter identification of the force-controlled flange system are carried out.A fuzzy proportion integral derivative(PID) controller is designed, in which fuzzy control is parallel with PID control. The effect of pure fuzzy control and fuzzy PID control is compared by Matlab simulation, and the influence of the parameters of fuzzy PID controller on the control performance is studied. Finally, an experimental platform based on Labview and peripheral component interconnect(PCI) data acquisition card is built, and the output force of the force-controlled flange end is realized experimentally. The simulation results show that pure fuzzy control can improve the system response performance, but there are some steady-state errors. After introducing PID control to fuzzy control, the simulation and experiment of the concurrent control prove that the steady-state error of step response is eliminated, and the sine following effect is improved obviously. The output force of constant force control fluctuates is in ±0.8N when expected force F is 10 N. Therefore, the constant force control of the end of the force-controlled flange can be realized by fuzzy PID control, and its dynamic response and robustness is preferable.