| 主权项 |
1. A stock-controlling method for a storage yarn feeder, said yarn feeder being provided with a drum which is driven to rotate by a motor controlled by a control unit for drawing yarn from a reel and winding it upon itself in the shape of a plurality of loops forming a stock, in which said control unit:
estimates the stock on the drum on the basis of an information indicative of the amount of yarn which is unwound from the drum upon request from a downstream machine, and of an information indicative of the amount of yarn which is wound on the drum, and retroactively controls said motor to substantially stabilize said stock on a reference value,
wherein said control unit also performs a parallel correction routine in which: compares said stock with said reference value to estimate a stock status
RES <REF_RES or RES >REF_RES,wherein RES is said estimated stock and REF RES is said reference value, compares said estimated stock status with a presence signal generated by sensor means adapted to generate an absolute binary information indicative of the presence/absence of yarn in a monitored area of the drum,
and in case of an inconsistency between said estimated stock status and said presence signal, said control unit corrects said stock so that it converges toward said monitored area of the drum. |
