Abstract: The optimum control conditions for a plurality of looms are simply estimated with the use of a trial loom. Hereby, the plurality of looms are operated under a centralized control method. The looms, even if they vary in their respective characteristics, can be effectively operated by correcting standard control data for controlling the looms in response to variations of the loom characteristics. The present centralized control method can save much labor and time to improve productivity of the looms, by properly eliminating elaborate trial weaving processes.

Abstract: A voltage to be applied to the primary winding of a drive motor is automatically and time-functionally adjusted in relation to the rated voltage of the drive motor in order to provide sufficiently large torque for beating during the starting period of the loom running and transit to normal running of the loom is carried out at a preselected moment other than the moment of beating motion. Change in voltage is effected through either switching in mode of connection for the primary winding or transforming the power source voltage which is maintained constant.

Abstract: A takeup motion control device for a loom includes an input setting unit for producing functions of a repetitive period and a takeup speed, a function generator for storing the functions in relation to r.p.m. of the loom, an arithmetic control unit for successively reading out the selected functions from the function generator in synchronism with rotation of the loom to generate a digital takeup command signal, a driver circuit for generating a drive signal in response to the takeup command signal and applying the drive signal to a servomotor for driving a winding roll to wind a woven fabric, and a digital feedback circuit for feeding an amount of rotation of the servomotor back to the arithmetic control unit.

Abstract: An apparatus for controlling a let-off motion in a loom having a let-off motion motor includes a tension detector for detecting a warp tension to produce a tension correction signal, a control unit responsive to the tension correction signal for producing a speed signal, a driving amplifier for controlling the let-off motion motor in response to the speed signal, a warp coil diameter detector for issuing a warp coil diameter correction signal inversely proportional to the diameter of a warp coil on a beam to the driving amplifier, and a normal-reverse rotation control unit responsive to the warp coil diameter correction signal for selectively applying prescribed normal- and reverse-rotation signals dependent on a rotation command to the driving amplifier. With this arrangement, the motor is rotated at a desired constant speed for feeding out or rewinding the warp yarn for a desired length irrespectively of the warp coil diameter.

Abstract: A method of controlling a motor-driven let-off motion in a loom including a system for controlling a let-off motion motor includes the steps of sampling a variation of warp tension during each revolution of a main shaft of the loom, effecting at least proportional and integral control modes on the average of sampled values, adding a proportional and integral output to a basic speed signal at a prescribed ratio, and applying a sum signal to the system for controlling the let-off motion motor.