Patent DE-19921429-A1 (DE)
Title: Sliver monitoring system used to give drawing operation a consistent sliver thickness, measures sliver speeds at the drawing unit allowing correction values to be computed
Inventor: DAEMMIG JOACHIM
IPC: D01G23/04
Filed: 1999-05-08
Abstract: To give a consistent  thickness of sliver a measured speed-related value is applied to a corresponding correction value. The resulting values, according to speed, form a steady rising or falling function curve and the correction values form an inverse and steady falling or rising function curve relative to the measured values.  The correction value is determined by signals which are proportional to the speed of the moving sliver (FM), and especially as series of pulses. The correction value is also taken from factors related to the sliver. The correction value is used after computing and/or matching for correction of the measured values. The signals, proportional to speed, are used in a unit (3) to generate the correction values, and also in a unit (4) for period duration measurement, where the registered period duration is passed to a processing station (5) to give a converted value to be matched (6) with at least one sliver-related factor as a correction value. The proportional speed signals are generated by a pulse transmitter (IG), to be passed to the period duration measurement unit (4). The periods, representing path segments, are generated (7) and passed to a period duration counter (9) with an oscillator (8) to give pulses at a fixed frequency, and then into memory (10). The stored data are taken from memory by the processing unit (5). The measurement unit (TR) has a pulse generator (IG). The unit (3) to generate the correction values is connected to the correcting unit (1). The matching unit (6) is operated manually. The correction value is formed from the measured values at the sliver and a comparison measured value, and the corrected value is developed from the corrected measured value of the sliver and the correction value, where all and/or each are related to the sliver speed, The measured values are taken at the sliver in given sections, to give a mean value. The comparison value is a value derived from high sliver speeds, and the mean value is preferably a sliding mean value, to be used in a correction table. The correction value is taken from the difference between the high speed mean value and the mean value. The corrected measurement value is the sum of the sliver measurement values and the correction value. The correction table is generated during sliver can changes.  An Independent claim is included for an assembly with a correction unit to give the corrected measurement value, and a correction value unit. The input side is linked to the monitors, which give the actual measured values and the correction value unit. The input side of the comparison unit is connected to the unit which forms the mean values, and it has the facility to form sliding mean values and/or a system to generate a correction table. The correction unit is linked to the sliver section monitors, and/or the sliver speed monitors. The memory is addressed according to the sliver or sliver section speed.