Design and experimental validation of the autoleveling control system for a high-speed drawing frame

Sliver quality in the spinning process can be enhanced significantly by using an autoleveling control system (ACS) of the drawing frame, which improves the uniformity of sliver linear density. Most existing research on closed-loop control systems focuses on theoretical analysis, and fixed-time open-loop control systems cannot accurately detect and control slivers. This paper develops and experimentally evaluates an open-loop fixed-length control system for the drawing frame to enhance the stability of the sliver thickness detection and improve the sliver quality, based on the fundamental autoleveling control equation. The proposed ACS adopts a digital signal processor (DSP) as its core, integrating key modules including a touchscreen, speed sensor, servo drive, sliver thickness sensor, and analog-to-digital converter. The autoleveling, communication, and online monitoring algorithms for sliver quality have all been implemented successfully. The proposed ACS is subsequently evaluated on an experimental platform to assess its performance. The proposed ACS reduces the CV 5m of the sliver by 93.10% compared with the unleveled sliver, improving sliver quality significantly. Compared with the existing advanced ACS, the proposed ACS reduces the root mean square error and average CV of sliver weight by 11.75% and 5.59%, respectively. This work provides theoretical and technical support for advancing domestic high-speed drawing frame development.