Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H23/00—Registering, tensioning, smoothing or guiding webs
  • B65H23/02—Registering, tensioning, smoothing or guiding webs transversely
  • B65H23/0204—Sensing transverse register of web
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S367/00—Communications, electrical: acoustic wave systems and devices
  • Y10S367/902—Speed of sound compensation

Definitions

• the invention relates to a method for detecting the position of the strip edge of a material web by means of an ultrasonic detector which is arranged in the strip edge region and consists of a transmitter and a receiver, the received sound waves being converted into an electrical signal.
• a pneumatic web edge sensor is used, which essentially consists of two nozzles arranged one above the other, namely the transmitter nozzle and the receiver nozzle, which are arranged in the area of the material web near the edge .
• the receiver pressure changes depending on the position of the material web and acts on a membrane drive, which in turn directs a liquid flow proportional to the receiver pressure to an actuator, which is usually designed as a control roller or an adjustable reel.
• the hydraulic amplification is often not sufficient to be able to adjust the response sensitivity of the control device in accordance with the technical requirements.
• the response sensitivity can only be increased by increasing the receiver pressure by increasing the transmitter pressure.
• the invention is based on the object of developing the method defined at the outset for detecting the position of a sand edge in such a way that undesired reflected waves certainly do not have any influence on the measurement result.
• the transmitter emits individual pulses or wave packets offset in time with respect to one another, in that the wave packet or individual pulse received by the receiver is converted into a corresponding electrical oscillation packet, in that a limited area of the vibration packet is scanned and the Sample is stored for further processing.
• the peak value that is determined in the sampling period of the oscillation packet area can be used particularly advantageously as the sample value.
• the method thus works in such a way that a wave packet from the ultrasound transmitter emitted and received by the receiver and converted into an electrical oscillation packet signal. Instead of a wave packet, individual pulses can also be used. Since the unwanted reflection rays only reach the receiver at a later point in time, by evaluating or scanning the first area of the oscillation packet, in which no undesired superimpositions yet occur, a measured value can be obtained that represents the position of the strip edge with great accuracy. If you limit the scanning range to a maximum of three to five periods, calculated from the beginning of the oscillation packet, the interference reflections will certainly be eliminated. The whole process is repeated cyclically and thus enables the material web to be continuously checked or monitored.
• One arrangement for carrying out the method is that the transmitter is fed by a pulse train generator, that an activatable peak rectifier is connected to the receiver that emits an electrical signal, and that an activatable transmission circuit is connected downstream for transmitting the peak value to a memory.
• a sequence control is provided which is acted upon by a pulse generator.
• the same pulses are also fed to the pulse train generator.
• the sequence control then ensures that a predetermined pulse sequence is sent out by the generator and the peak value rectifier is activated at a specific point in time for a specific sampling period, the peak value determined subsequently being fed to a memory via a transmission circuit.
• the measurement can take place both in reflection and in the direct transmission method.
• the transmitter and receiver are arranged on the same side of the material web at a certain angle, the beam reflected on the material web forming the measuring beam.
• an ultrasonic transducer can alternately be used as a transmitter and receiver in a known manner.
• the transmitter is on one side and the receiver on the other side of the material web, sound waves of different energy reaching the receiver depending on the degree of coverage of the beam by the web.
• Fig. 3 is a flow chart to explain the Verfa ensa run.
• Fig. 1, 1 schematically indicates the material web which is guided over rollers, not shown.
• the transmitter 2 is located above the material web, while the receiver 3 is arranged below the material web.
• the transmitter and receiver are arranged in the edge area of the material web, so that the sound beam is partially covered by the material web. Depending on the degree of coverage, more or less sound energy reaches the receiver, which represents a measure of the position of the strip edge or the material web.
• the reflection method not shown, can also be used.
• the transmitter and receiver are arranged at a suitable angle on one side of the material web.
• the sound beam emitted by the transmitter is reflected on the material web and then reaches the receiver.
• rays reflected at other points also enter the receiver, which amplify or weaken the measuring beam and thus lead to a falsification of the measurement result.
• the material web 1, the transmitter 2 and the receiver 3 are again shown schematically.
• the ultrasonic transmitter 2 is fed by an impulse sequence generator 4, which emits a specific impulse sequence of a predetermined repetition frequency.
• an impulse sequence generator 4 which emits a specific impulse sequence of a predetermined repetition frequency.
• the method can also be carried out with individual pulses.
• a pulse generator is used instead of the pulse train generator 4.
• This electrical pulse sequence is converted in the transmitter into a wave packet, emitted and received as a wave packet from the receiver, the energy received being determined by the degree of coverage of the beam by the material web.
• the sound waves are converted directly into electrical signals in the receiver, if necessary amplified in an amplifier 5 and then fed to an activatable scanning device 6.
• the scanning device 6 has a switch 7 which supplies the signals emitted by the amplifier 5 to the peak value rectifier 8.
• the peak rectifier 8 consists, for example, of the interconnection of a diode with a capacitor, as is symbolically shown.
• the switch 7 is opened and the value held in the peak value rectifier is fed to a memory circuit 9 by means of a transmission circuit 9.
• the transmission circuit 9 can consist, for example, of a switch 1 and a capacitor 10.
• the switch 1 When the switch 1 is closed, the charge is transferred from the peak value rectifier to the capacitor 10 and then fed to a memory (not shown) for further processing.
• Fig. 3 used.
• the discharge control is acted upon by a pulse generator 13, which simultaneously delivers pulses to the pulse train generator 4 l.
• the sequence control closes switch 14 and activates the pulse train generator, which for example emits a pulse train with three pulses. Accordingly, the transmitter 2 emits a wel lencou with the same period.
• the switch 14 is opened via the sequence control 12 and the switch 7 is closed.
• the time difference T2 - T1 corresponds approximately to the running time of the sound waves from the transmitter to the receiver.
• the switch 7 remains closed so long that approximately three periods are detected by the scanning circuit 6.
• switch 7 opens and the peak value rectifier maintains the peak value that occurs in the time range T3-T2.
• switch 1 1 is closed and the peak value is transferred to a memory 10.
• the peak rectifier is then reset to zero and the cycle begins again. In this way it is ensured that only the measurement signal is detected during the scanning period and that no disturbing reflections which would occur at a later point in time influence the measurement value.

Landscapes

• Length Measuring Devices Characterised By Use Of Acoustic Means (AREA)
• Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
• Geophysics And Detection Of Objects (AREA)
• Registering, Tensioning, Guiding Webs, And Rollers Therefor (AREA)
• Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6250608

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Country Status (5)

Cited By (1)

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Citations (6)

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• 1984
  • 1984-11-17 DE DE19843442154 patent/DE3442154A1/de active Granted
• 1985
  • 1985-11-09 JP JP60505127A patent/JPH06105172B2/ja not_active Expired - Lifetime
  • 1985-11-09 DE DE8585905810T patent/DE3567618D1/de not_active Expired
  • 1985-11-09 WO PCT/EP1985/000598 patent/WO1986002913A1/de active IP Right Grant
  • 1985-11-09 EP EP85905810A patent/EP0201576B2/de not_active Expired - Lifetime
  • 1985-11-09 US US06/888,322 patent/US4901292A/en not_active Expired - Lifetime

Patent Citations (6)

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