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 ±0.8 N 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.