EP0095779A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of and apparatus for detecting weft yarn in jet looms
Assignee: Tsudakoma Corp
•
Filing: 1983-05-31
•
Granted: —
•
Expires: 2003-05-31
Abstract
Abstract The amplitude of a signal (original waveform) produced by weft feelers is relativized, and the signal waveform is analyzed in various aspects based on multiple parameters to discriminate a weft yarn and a jet of fluid accurately. More specifically, a discriminating function is calculated beforehand from a signal indicative of the weft yarn and jet of fluid under normal weft insertion condition, and a signal produced in actual detection operation is compared with the discriminating function to determine whether the weft yarn is present or not. The discriminating function can be obtained by extracting feature parameters from a signal generated by the weft feelers, relativizing the feature parameters with respect to the original signal waveform to find a reference quantity. The feature parameters include the original waveform per se, a differentiated value thereof, an integrated value thereof, frequencies in certain frequency ranges, and sampling averages of the above parameters. The parameter relativization is carried out by finding ratios and differences between the feature parameters. The discriminating function is created by a statistic method.
Inventors
- 👤 Katsuhiko Sugita
- 👤 Tsutomu Sainen
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 01:06
CPC Classifications
D; D03; D03D; D03D51/00; D03D51/18; D03D51/34
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
146 words
A method of detecting a weft yarn inserted by a jet of fluid through a warp shed in a jet loom, comprising the steps of: (a) producing a signal indicative of whether weft yarn and the jet of fluid are present or not; (b) extracting feature parameters inherent in the weft yarn and the jet of fluid from an original waveform of the produced signal; (c) relativizing amplitudes of the feature parameters with respect to the original waveform of the produced signal or a converted waveform thereof to calculate a reference quantity; (d) calculating a discriminating function from said reference quantity; (e) establishing a reference value for determining whether the weft yarn is present or not from said discriminating function; and (f) comparing a discriminating function obtained for weft yarn detection with said reference value to thereby determine whether the weft yarn is present or not.
Claim 2
Independent Claim
146 words
A method of detecting a weft yarn inserted by a jet of fluid through a warp shed in a jet loom, comprising the steps of: (a) producing a signal indicative of whether weft yarn and the jet of fluid are present or not; (b) extracting feature parameters inherent in the weft yarn and the jet of fluid from an original waveform of the produced signal; (c) relativizing amplitudes of the feature parameters with respect to the original waveform of the produced signal or a converted waveform thereof to calculate a reference quantity; (d) calculating a discriminating function from said reference quantity; (e) establishing a reference value for determining whether the weft yarn is present or not from said discriminating function; and (f) comparing a discriminating function obtained for weft yarn detection with said reference value to thereby determine whether the weft yarn is present or not.
Claim 3
Independent Claim
234 words
An apparatus for detecting a weft yarn inserted by a jet of fluid through a warp shed in a jet loom, comprising: (a) a nozzle for ejecting a jet of fluid to insert a weft yarn through a warp shed; (b) a pair of feelers disposed remotely from said nozzle across said warp shed for detecting whether the weft yarn is present or not; (c) an amplifier connected to said pair of feelers for amplifying an electric signal generated by said feelers; (d) a feature extracting circuit connected to said amplifier for extracting feature parameters inherent in the weft yarn and the jet of fluid from an original waveform of the signal; (e) a scaling circuit connected to said feature extracting circuit for comparing amplitudes of the feature parameters with the original waveform or a converted waveform thereof to calculate a reference quantity; (f) a discriminating function calculating circuit connected to said scaling circuit for calculating a discriminating function from said reference quantity; (g) a reference setting circuit for establishing a reference indicative of whether the weft yarn is present from a discriminating function obtained by experimental weft insertion; and (h) a discriminating circuit connected to said reference setting circuit and said discriminating function calculating circuit for comparing a discriminating function resulting from a signal generated for weft yarn detection with said reference to thereby determine whether the weft yarn is present or not.
Claim 4
Independent Claim
234 words
An apparatus for detecting a weft yarn inserted by a jet of fluid through a warp shed in a jet loom, comprising: (a) a nozzle for ejecting a jet of fluid to insert a weft yarn through a warp shed; (b) a pair of feelers disposed remotely from said nozzle across said warp shed for detecting whether the weft yarn is present or not; (c) an amplifier connected to said pair of feelers for amplifying an electric signal generated by said feelers; (d) a feature extracting circuit connected to said amplifier for extracting feature parameters inherent in the weft yarn and the jet of fluid from an original waveform of the signal; (e) a scaling circuit connected to said feature extracting circuit for comparing amplitudes of the feature parameters with the original waveform or a converted waveform thereof to calculate a reference quantity; (f) a discriminating function calculating circuit connected to said scaling circuit for calculating a discriminating function from said reference quantity; (g) a reference setting circuit for establishing a reference indicative of whether the weft yarn is present from a discriminating function obtained by experimental weft insertion; and (h) a discriminating circuit connected to said reference setting circuit and said discriminating function calculating circuit for comparing a discriminating function resulting from a signal generated for weft yarn detection with said reference to thereby determine whether the weft yarn is present or not.
Claim 5
Dependent Claim
34 words
An apparatus according to claim 2, including an A/D converter connected between said feature extracting circuit and said scaling circuit for entering a digital signal indicative of the produced signal into said scaling circuit.
Claim 6
Dependent Claim
28 words
An apparatus according to claim 3, wherein said scaling circuit, said discriminating function calculating circuit, and said discriminating circuit are constructed as part of a central processing unit.
Claim 7
Dependent Claim
34 words
An apparatus according to claim 2, including an A/D converter connected between said amplifier and said feature extracting circuit for entering a digital signal indicative of the produced signal into said feature extracting circuit.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.