METHOD AND APPARATUS FOR CONTROLLING MOTOR-DRIVEN LET-OFF MOTION FOR LOOMS

摘要

Motor-driven let-off motion control gives increased tension detection and stabilizes restarting characteristics. Control of motor-driven let-off motion comprises sampling the rippled variations in the tension of warp uarns each time the main shaft of a loom makes one revolution. A composite PI(proportionalintegral) control mode is effected on the average of the sampled values for the quick detection of tension variations. While the loom is at rest, the integrated values of the sampled tensions in the PI control mode are stored in preparation for achieving stable characteristies when the loom is to be set in motion again. A PI output is kept at a certain ratio with respect to a fundamental speed for ideal tension compensation which will not be relatively varied even when the diameter of the warp cils is reduced.