Method of controlling the yarn tension in a weaving machine

Method for controlling weft yarn tension and warp yarn tension in a weaving machine having a drive shaft which rotates through discrete positions of shaft rotation to cause yarn being woven in the weaving machine to come under variable tension as a function of shaft rotation, the method of controlling yarn tension comprising the steps of:

• selecting at least one desired yarn tension value for yarn in the weaving machine;
• measuring a first actual yarn tension data in the weaving machine as a function of shaft rotation and yarn tension at discrete positions of shaft rotation;
• calculating a first tension control curve as a function of shaft rotation and yarn tension at discrete positions of shaft rotation by comparing the desired yarn tension value with the measured first actual yarn tension data to cause actual yarn tension in the weaving machine to approach the desired yarn tension value;
• applying the first tension control curve to the weaving machine by varying at least one of the control parameters from the group consisting of measured yarn tension, values of yarn breakage, braking force, time of braking force as a function of shaft rotation, beat up force of reed or shed, opening of the shed, through pass time of inserted weft yarn, fastener or clip inclination of warp yarn, warp let off, yarn rest, and cloth take off;
• measuring a second actual yarn tension data in the weaving machine as a function of shaft rotation and yarn tension at discrete positions of shaft rotation with the first tension control curve applied to the weaving machine;
• calculating a second tension control curve as a function of shaft rotation and yarn tension at discrete positions of shaft rotation by comparing the desired yarn tension value with the measured second actual yarn tension data to cause actual yarn tension in the weaving machine to further approach the desired yarn tension value;
• applying the second tension control curve to the weaving machine by varying at least one of the control parameters from the group consisting of measured yarn tension, values of yarn breakage, braking force, time of braking force as a function of shaft rotation, beat up force of reed or shed, opening of the shed, through pass time of inserted weft yarn, fastener or clip inclination of warp yarn, warp let off, yarn rest, and cloth take off;
• and,
• weaving with the weaving machine having the second tension control curve applied to the weaving machine to further approach the desired yarn tension value.