Abstract: Abstract In view of the electronic yarn let-off system response lag and obvious stripe when high-speed switching on warp knitting , A kind of fuzzy PID algorithm for electronic yarn let-off system had been developed by combined fuzzy control and common PID control, the fuzzy PID technology is introduced to revise the warp beam motor running speed real-time ,and the PID parameters of yarn let-off system were adjusted online. Therefore, the system dynamic performance is greatly improved. By use of MTLAB, PID control and fuzzy PID control are simulated ,by the contrast and analysis of the outcomes of simulations, that the fuzzy PID control could effectively raise the response speed of warp beam motor, reduce overshoot and steady-state errors, and have powerful ability of restraining external disturbance ,optimize the overall performance of the electronic yarn let-off system.

Key words: warp knitting, electronic yarn let-off system, response characteristic, fuzzy PID, control algorithm