Exemplary embodiments pertain to the art of elevator systems. More particularly, the present disclosure relates to detection and correction of suspension member sway of elevator systems.
Elevator systems are useful for carrying passengers, cargo, or both, between various levels in a building. Some elevators are traction based and utilize suspension members such as ropes or belts for supporting the elevator car and achieving the desired movement and positioning of the elevator car.
Rope sway of elevator systems can cause damage to ropes and other objects or equipment in the hoistway of the elevator system. Further, rope sway causes undesirable vibrations, which leads to passenger discomfort. Rope sway is typically not measured directly, but is instead assessed by sensing contributing conditions, such as building sway or vibration. When building sway is detected, action is taken to limit travel of the elevator cars of the elevator system, and/or to stop operation of the elevator cars until the building sway event passes.
Utilizing secondary conditions such as building sway to assess rope sway may result in false triggers when a rope sway event is not occurring, and may fail to trigger a response when a rope sway event is occurring.
In one embodiment, a rope sway detection system of an elevator system includes a magnetic pickup located adjacent to a suspension member of an elevator system. The magnetic pickup is configured to detect a movement of the suspension member via a change in a magnetic field at the magnetic pickup. A signal processing unit is operably connected to the magnetic pickup. The signal processing unit is configured to determine a maximum amplitude of a sway of the suspension member based on the change in the magnetic field, compare the maximum amplitude to a preselected threshold, and signal a change in operation of the elevator system based on an actual or predicted exceedance of the threshold.
Additionally or alternatively, in this or other embodiments two or more magnetic pickups are located at the hoistway, at some angle apart relative to a rope central axis.
Additionally or alternatively, in this or other embodiments wherein the magnetic pickup is selectably retractable.
Additionally or alternatively, in this or other embodiments a power driver is operably connected to the magnetic pickup.
Additionally or alternatively, in this or other embodiments the power driver and the magnetic pickup are configured to emit an actuation signal to disrupt sway of the suspension member.
Additionally or alternatively, in this or other embodiments the power driver and the magnetic pickup are configured to emit a holding signal to attract the suspension member to the magnetic pickup.
In another embodiment, an elevator system includes a hoistway, an elevator car located in the hoistway, a suspension member operably connected to the elevator car to move the elevator car along the hoistway, and a rope sway detection system located in the hoistway. The rope sway detection system includes a magnetic pickup positioned adjacent to the suspension member. The magnetic pickup is configured to detect a movement of the suspension member via a change in a magnetic field at the magnetic pickup. A signal processing unit is operably connected to the magnetic pickup. The signal processing unit is configured to determine a maximum amplitude of a sway of the suspension member based on the change in the magnetic field, compare the maximum amplitude to a preselected threshold, and signal a change in operation of the elevator system based on an actual or predicted exceedance of the threshold.
Additionally or alternatively, in this or other embodiments two or more magnetic pickups are located at the hoistway, at some angle apart relative to a rope central axis.
Additionally or alternatively, in this or other embodiments the magnetic pickup is selectably retractable.
Additionally or alternatively, in this or other embodiments a power driver is operably connected to the magnetic pickup.
Additionally or alternatively, in this or other embodiments the power driver and the magnetic pickup are configured to emit an actuation signal to reduce sway of the suspension member.
Additionally or alternatively, in this or other embodiments the power driver and the magnetic pickup are configured to emit a holding signal to attract the suspension member to the magnetic pickup.
Additionally or alternatively, in this or other embodiments the magnetic pickup is located at or near a drive sheave of the elevator system.
Additionally or alternatively, in this or other embodiments the suspension member is a rope formed from a plurality of metallic wires.
Additionally or alternatively, in this or other embodiments the rope sway detection system is configured to sense one or more of speed of the elevator car or operational frequency of an elevator drive.
In yet another embodiment, a method of detecting movement of a suspension member of an elevator system includes positioning a magnetic pickup adjacent to the suspension member, sensing a change in a magnetic field of the magnetic pickup indicative of movement of the suspension member, and determining a maximum amplitude of the movement based on the change in the magnetic field.
Additionally or alternatively, in this or other embodiments the maximum amplitude is compared to a predetermined threshold, and operation of the elevator system is changed based on an actual or predicted exceedance of the threshold.
Additionally or alternatively, in this or other embodiments an actuation signal is transmitted from the magnetic pickup toward the suspension member to reduce movement of the suspension member.
Additionally or alternatively, in this or other embodiments a holding signal is emitted from the magnetic pickup to attract the suspension member to the magnetic pickup to reduce movement of the suspension member.
Additionally or alternatively, in this or other embodiments one or more of speed of the elevator car or operational frequency of an elevator drive are sensed.
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
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Movement of the suspension rope 16 relative to the magnetic pickup 36 causes a change in a magnetic field 42 of the magnetic pickup 36, thus resulting in a change in voltage across the coil 40. The measured voltage is analyzed and processed at a signal processing unit 44 to infer a maximum amplitude of a travelling wave of suspension rope 16 movement. The inferred maximum amplitude is compared to a threshold, and the result is communicated to an elevator control system 46 so that proper action, such as restricting movement of the elevator car 12, or stopping operation of the elevator system 10 may be taken.
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A method of operating the rope sway detection system 34 is illustrated in
Further, in some embodiments, analysis by the signal processing unit 44 may be predictive, looking at how the threshold changes over time and then signaling the elevator control system 46 in advance of a predicted sway event to change operation of the elevator system 10 based on prediction of the sway event. Further, in other embodiments, the magnetic pickup 36 may be wired to the elevator control system 46 and the signal processing logic could be located in the elevator control system 46.
In addition to sway of the suspension rope 16 and sway of the compensation rope 26, other operational properties of the elevator system 10 may be sensed or monitored by the rope sway detection system 34. For example, the rope sway detection system 34 may be utilized to sense an operational frequency of the elevator drive (not shown) that commands voltage to the machine 24 with pulse width modulation (PWM). PWM has one or more frequencies that can be observed by the magnetic pickup 36, since it is in close proximity to the drive & motor windings.
Further, the magnetic pickup 36 may detect variation in suspension rope 16 surface passing the magnetic pickup 36, and based on the sensed frequency, the speed of the elevator car 12 may be determined. Further, the magnetic pickup 36 may be utilized for load sensing of the elevator car 12 and/or relative rope 16 tension in a system 10 with multiple ropes 16 and multiple magnetic pickups 36.
In some embodiments, such as shown in
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The rope sway detection system 34 disclosed herein provides direct sensing and measurement of rope sway, and also solutions for reducing and or stopping rope sway once detected. The system is relatively low cost, and may be easily implemented into existing elevator systems.
The term “about” is intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and/or groups thereof.
While the present disclosure has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this present disclosure, but that the present disclosure will include all embodiments falling within the scope of the claims.
This application claims the benefit of U.S. Provisional Application No. 62/645,511, filed Mar. 20, 2018, which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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62645511 | Mar 2018 | US |