Patent ID: 8091589

Claim:
A loom comprising: a warp beam around which warps are wound; a feed motor rotating the warp beam in a direction feeding the warps; a heddle opening and closing the warps fed from the warp beam; a picking device inserting wefts into the openings of the warps formed by the heddle; a reed beating down the wefts inserted in the openings by the picking device; a pull-in roller pulling in a woven fabric beaten down by the reed and formed by the warps and the wefts; a pull-in motor rotating the pull-in roller in a direction pulling in the woven fabric; a detector detecting a tension of the warps between the warp beam and the pull-in roller; and a control device having an adaptive filter filtering the tension detected by the detector, and controlling the feed motor and the pull-in motor so that the tension of the warps becomes a predetermined target tension based on the tension filtered by the adaptive filter; wherein the adaptive filter includes: a filter part filtering tension detected by the detector by using a plurality of first filter coefficients, and a filter constant estimation part calculating the plurality of first filter coefficients; the filter part includes: a plurality of first delay elements sequentially delaying tension detected by the detector, a plurality of first multipliers multiplying outputs of the plurality of first delay elements by the first filter coefficients corresponding to the first delay elements, and a first accumulation part accumulating results of multiplication of the plurality of first multipliers and outputting the result of the accumulation as the filtered tensions; the filter constant estimation part includes: a pass band signal generation part generating a pass band signal, an adder adding the tension detected by the detector and the pass band signal, an estimation filter part filtering results of addition of the adder by using a plurality of second filter coefficients, a subtractor calculating a deviation between the output filtered by the estimation filter part and the pass band signal, and a tap constant estimation part calculating a plurality of second filter coefficients so that the deviation becomes small; the estimation filter part includes: a plurality of second delay elements sequentially delaying results of addition of the adder, a plurality of second multipliers multiplying outputs of the plurality of second delay elements by the second filter coefficients corresponding to the delay elements, and a second accumulation part accumulating results of multiplication of the second multipliers and outputting the result of the accumulation as the filtering result, the tap constant estimation part calculates the plurality of second filter coefficients so that the deviation becomes small; and the calculated plurality of second filter coefficients are set as the first filter coefficients in the filter part.