Research on adaptive S-type curve control method for hydraulic fine-blanking press in automotive component manufacturing

During the production process of hydraulic fine-blanking presses (FBPs), significant hydraulic impacts and equipment damage occur due to rapid large-span opening and closing of hydraulic valve ports during stage transitions. The fast approach (FA) and fast return (FR) stage exhibit the most pronounced speed variations, leading to severe hydraulic impact that reduces the precision and quality of automotive parts molding. To address this issue, we propose an adaptive S-type curve for the FA and FR stages, integrated with a feedback linearization sliding mode control (FLSMC) system to precisely regulate the slide block speed. Experimental results demonstrate that the proposed system eliminates acceleration, deceleration, startup, and shutdown impacts during the FA stage. The controller achieves high precision, robust dynamic performance, and stable operation. Experimental results demonstrate that the proposed system eliminates acceleration, deceleration, startup, and shutdown impacts during the FA stage. The maximum pressure peak is reduced by 30.1%, the instantaneous pressure change rate is decreased by 45.7%, and the fitting degree between the actual slide block displacement and the designed S-curve reaches 97.4% in the FA stage and 96.3% in the FR stage. Effectively reducing hydraulic impact issues, this system improves accuracy of slider movement while enhancing manufacturing precision of gears, transmission components, and structural automotive parts.