Modeling of fuzzy control in sheet deep drawing
板料拉深成形液压系统模糊控制建模

To deal with the undesirable dynamic response and the low steady-state precision of the hydraulic control in sheet-deep drawing, a fuzzy control model is built based on fuzzy adaptive PID adjustment rules. The look-up table for optimal control parameters is generated from MATLAB Toolbox. Two load profiles of variable blank holder force (VBHF) in real tests are applied for testing the real-time effect of VBHF. Experimental results show that when the input signal is a constant VBHF, the over-shoot under this fuzzy control of adaptive PID controller is less than 4.25% of the set-point value, in comparison with the 21.24% with no PID controller and the 31.07% with conventional PID controller. The regulation height and the regulation time are reduced to 5 mm and 0.24 s respectively. When the input signal is a U mode of VBHF, the over-shoot is decrease by 5% from the value when no PID is applied, and the regulation height also decreased by 1 mm. These demonstrate that the proposed fuzzy model effectively improves the dynamic response and raises the steady-state precision of the VBHF system.