Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66B—ELEVATORS; ESCALATORS OR MOVING WALKWAYS
  • B66B13/00—Doors, gates, or other apparatus controlling access to, or exit from, cages or lift well landings
  • B66B13/24—Safety devices in passenger lifts, not otherwise provided for, for preventing trapping of passengers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66B—ELEVATORS; ESCALATORS OR MOVING WALKWAYS
  • B66B13/00—Doors, gates, or other apparatus controlling access to, or exit from, cages or lift well landings
  • B66B13/24—Safety devices in passenger lifts, not otherwise provided for, for preventing trapping of passengers
  • B66B13/26—Safety devices in passenger lifts, not otherwise provided for, for preventing trapping of passengers between closing doors
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J40/00—Photoelectric discharge tubes not involving the ionisation of a gas
  • H01J40/02—Details
  • H01J40/14—Circuit arrangements not adapted to a particular application of the tube and not otherwise provided for
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
  • G01V8/00—Prospecting or detecting by optical means
  • G01V8/10—Detecting, e.g. by using light barriers

Definitions

• the present invention relates to a method for detecting energy interference in an optically synchronized safety detection system for sliding elevator doors and compensating for such interference.
• the energy produced by an emitter array is produced in a fixed sequence or pattern, and the receiver array predictively enables or activates individual receivers according to the fixed sequence produced by the emitters.
• a "connect" is logged for the individual beam being sampled (composed of the specific emitter and its corresponding receiver) .
• the receiver array then disables the currently enabled receiver and activates the next receiver in the scanning sequence. This process continues as long as beams connect.
• Broken beams (those for which an individual receiver does not detect emitted energy within a specified maximum wait time) cause the detection system to signal a door controller to reopen the doors due to the detection of an obstruction in the path of the closing doors.
• a drawback of one such optically synchronized detection system is the potential presence of various external sources of light energy or electrical noise which can interfere with the optical and synchronization, or sync, functionality of the scan. If the energy produced by these external sources is modulated similarly to the energy transmitted by the door safety system, the external energy can be received by the system and interpreted as detection scanning beam energy produced by the emitter array and cause false indexing of receivers to check the next beam in the scan sequence.
• Sources of interference light energy include fluorescent lighting systems, strobe lights associated with fire alarm systems, and beacons atop emergency vehicles.
• Sources of external, impulse type, electrical noise include relay type elevator controllers and electromechanical door operators.
• a method for detecting interference energy in a sliding door safety system comprises the steps of disposing at least one emitter along a first vertical surface, disposing at least one receiver corresponding to the at least one emitter along a second vertical surface, activating the at least one receiver, activating the at least one emitter to emit an energy beam comprising a modulated square wave of a predetermined frequency, sampling an energy intensity received by the activated at least one receiver a predetermined number of times recording each time a received energy intensity to form a plurality of recorded energy intensities, selecting the lowest magnitude one of the plurality of recorded energy intensities to form a lowest recorded energy intensity, comparing the lowest recorded energy intensity to a threshold value and determining a source of the energy intensity to be external when the lowest recorded energy intensity is less than the threshold value.
• the aforementioned method additionally comprises the steps of performing statistical analysis upon the plurality of recorded received energy intensities to determine a measure of consistency amongst the plurality of recorded received energy intensities when the source of the energy intensity has not previously been determined to be external, and determining a source of the energy intensity to be external if the measure of consistency is sufficiently low.
• the aforementioned method additionally comprises the additional steps of modulating the energy beam with a predefined binary code, sampling an energy signal received by the activated at least one receiver a predetermined number of times recording each time a received energy signal to form a plurality of recorded energy signals, and verifying the presence of the predefined binary code in at least one of the sampled plurality of recorded energy signals.
• FIG. 1 A diagram of an elevator sliding door system to which the present invention is directed.
• FIG. 2 A diagram of a modulated square wave for use in the elevator sliding door system of the present invention.
• FIG. 3 A diagram of a modulated binary code square wave for use in the elevator sliding door system of the present invention.
• FIG. 1 With reference to Figure 1 there is illustrated a vertically arranged array of emitters 11 located along the right door 21 of an elevator sliding door system 10 and a matched, vertically arranged, array of receivers 17 located along the left door 23 of an elevator sliding door system 10. While illustrated with reference to a plurality of emitters 11 and receivers 17 arranged vertically and programmed to emit and receive a plurality of energy beams in a predefined sequence, the present invention is not so limited. Rather, the present invention is broadly drawn to encompass any and all configurations of emitters and receivers arranged to perform a safety scan in an environment wherein spurious, external, electromagnetic signals may interfere with emitted energy beams.
• a representation of the energy beam 23 produced by a single active emitter 15 is shown.
• the energy beam 23 comprises IR energy.
• a single active emitter 15 is turned on and a receiver 17 directly across from the emitter is activated to form an active receiver 13 is turned on and remains on until it detects the energy beam's 23 signal. After detecting the energy beam 23, the active receiver 13 is disabled and the next receiver 17 in the scan sequence in activated to become the active receiver 13 and to receive the energy beam 23.
• the received energy beam 23 signal triggers the next receiver 17 in the sequence to be activated, and so on. This pattern repeats for each emitter/receiver pair.
• each beam is sampled multiple times in each door scan frame.
• the sampling is accomplished by modulating the energy transmitted with a continuous stream of square waves, at a specified frequency.
• Each beam is sampled successively up to a pre-set maximum number of times. The value of the smallest amplitude sample so acquired is the value actually stored and used as the beam intensity for that beam. If, at any time, during the sampling of a particular beam, no energy is detected, the beam intensity is set to zero.
• the stored beam intensity is compared to a predetermined threshold value. If the stored beam intensity is less than the predetermined threshold value, the presence of impulse type energy from an external source is confirmed.
• impulse energy is out of phase with the frequency at which the sampling is performed.
• at least one sample resulting from impulse energy will exhibit a low magnitude. In this way, impulse type energy from external sources can be quickly and easily ignored.
• each beam is sampled multiple times in each door scan frame.
• the sampling is accomplished by modulating the energy transmitted with a continuous stream of square waves 21 at a specified frequency as illustrated in Figure 2. Multiple sampling and impulse rejections is performed as described for the simplest embodiment above. However, if no sample for a particular beam results in a determination that the energy received originated external to the detection system, the resulting energy samples acquired for that beam are compared to determine if the detected energy represents the pickup of external energy or actual scanning energy being produced by the detection system.
• the determination is made that the received energy originated external to the safety system and is rejected. If the amplitude of the energy is consistent, from sample to sample, the determination is made that the energy was actually scanning energy produced by the detection system. In a preferred embodiment, a maximum amplitude deviation amongst all of the samples is computed and analyzed to determine if the samples, taken as a whole, are sufficiently consistent to confirm that the received energy came from the detection system. However, any number of forms of statistical analysis may be performed to determine the consistency of the samples.
• each beam is sampled multiple times in each door scan frame.
• the sampling is accomplished by modulating the energy transmitted with a specific binary code 31 as illustrated in Figure 3.
• the binary code expected to be modulating the received signal is verified.
• Multiple sampling and impulse rejection is performed, just as described above. However, if no sample for a particular beam results in a "no detect", the resulting energy samples for that beam, are compared to determine if the detected energy represents the pickup of external energy or actual scanning energy being produced by the detection system.
• the determination is made that the received energy originated external to the safety system and is rejected. If the amplitude of the energy is consistent, from sample to sample, or the binary modulation code is verified, the determination is made that the energy was actually scanning energy produced by the detection system.

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• Elevator Door Apparatuses (AREA)
• Power-Operated Mechanisms For Wings (AREA)

Applications Claiming Priority (1)

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• 2002
  • 2002-12-31 AU AU2002358313A patent/AU2002358313A1/en not_active Abandoned
  • 2002-12-31 CN CNB028301234A patent/CN100524604C/zh not_active Expired - Fee Related
  • 2002-12-31 JP JP2004563169A patent/JP4292159B2/ja not_active Expired - Fee Related
  • 2002-12-31 KR KR1020057011029A patent/KR100956728B1/ko not_active IP Right Cessation
  • 2002-12-31 WO PCT/US2002/041816 patent/WO2004059692A1/en active Application Filing
  • 2002-12-31 EP EP02792553.6A patent/EP1588397A4/de not_active Withdrawn
• 2006
  • 2006-07-03 HK HK06107473.5A patent/HK1087529A1/xx not_active IP Right Cessation

Non-Patent Citations (1)

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