System and method for safety management in roll-up doors
A safety curtain and system includes multiple light emitters and multiple light receivers to detect traffic approaching a doorway. The safety curtain may include pairs of multiple light emitters and receivers positioned on both sides of a passageway (doorway) so as to detect approaching traffic. The multiple light emitters and light receivers may detect a height of an approaching traffic (e.g., person or vehicle) and initiate warning lights of a possible door closing. The detected approach of traffic may cause the door to be stopped, reversed or slow down. The system may include a computer to monitor the signals from the receivers and may control the motion of the door.
1 . A method for controlling an overhead door assembly comprising:
defining a protected area around a doorway opened and closed by a door panel, the protected area being defined between a first light curtain placed on a first side of the doorway and a second light curtain placed on a second side of the doorway;
monitoring the protected area surrounding a doorway by detecting traffic or objects entering or exiting the protected area;
identifying traffic shapes or object shapes as the traffic or objects pass through the first light curtain to enter or exit the protected area;
identifying traffic shapes or object shapes as traffic or objects pass through the second light curtain to enter or exit the protected area;
comparing traffic shapes and object shapes passing through the first light curtain and the second light curtain; and
preventing normal operation of the door panel if any traffic shape or object shape identified when passing through the first light curtain or the second light curtain has not been identified as passing through the first light curtain or the second light curtain a second time.
2 . The method of claim 1 , further comprising the step of providing at least one plurality of light beam emitters and at least one plurality of light beam receivers on the first side of the doorway to form the first light curtain, wherein the traffic shape or object shape entering or exiting the protected area is identified by
monitoring which light beam receivers from the at least one plurality of light beam receivers do not receive a light beam;
monitoring the order in which each light beam receiver from the at least one plurality of light be receivers stops receiving a light beam occur; and
monitoring the duration each light beam receiver from the at least one plurality of light beam receivers fails to receive a light beam for.
3 . The method of claim 2 , further comprising the step of providing at least a second plurality of light beam emitters and at least a second plurality of light beam receivers on the second side of the doorway to form the second light curtain, wherein the traffic shape or object shape entering or exiting the protected area is identified by
monitoring which light beam receivers from the first plurality of light beam receivers and the at least second plurality of light beam receivers do not receive a light beam;
monitoring the order in which each light beam receiver from the first plurality of light beam receivers and the at least second plurality of light beam receivers stops receiving a light beam occur; and
monitoring the duration each light beam receiver from the first plurality of light beam receivers and the second plurality of light beam receivers fails to receive a light beam for.
4 . The method of claim 1 , further comprising the step of warning approaching traffic or objects of impending movement of the door panel.
5 . The method of claim 4 , further comprising the step of warning approaching traffic or objects that the door panel is moving.
6 . The method of claim 1 , further comprising the step of warning approaching traffic or objects that other traffic or objects have entered the protected zone.
7 . The method of claim 1 , wherein controlling the movement of the door panel is holding the door panel in an open position until a traffic shape or object shape is detected exiting the protected area which matches every traffic or object shape detected entering the protected zone.
8 . The method of claim 1 , wherein controlling the movement of the door panel is closing the door panel at a rate slower than a normal closing rate until a traffic shape or object shape is detected exiting the protected area which matches every traffic or object shape detected entering the protected zone.
9 . The method of claim 1 , further comprising the step of providing a visual warning once traffic or objects are detected entering the protected zone until traffic or objects having a matching shape are detected exiting the protected zone.
10 . The method of claim 1 , further comprising the step of presetting a tolerance for changes in object shape, wherein the step of comparing traffic shapes and object shapes passing through the first light curtain and the second light curtain considers traffic or objects having a shape within a preset tolerance in change of shape passing through the first light curtain or the second light curtain as being a second pass through for traffic shape or object shape previously identified as passing through either the first light curtain or the second light curtain.
11 . A method for controlling an overhead door assembly comprising:
monitoring a protected area surrounding a doorway by detecting traffic or objects entering the protected area;
identifying an overall size of traffic or objects as the traffic or objects enter the protected area;
identifying an overall size of traffic or objects as the traffic of objects exit the protected area; and
monitoring whether the overall size of traffic or objects exiting the protected area matches the overall size of traffic or objects which have entered the protected area.
12 . The method of claim 11 , further comprising the step of providing at least one plurality of light beam emitters and at least one plurality of light beam receivers on a first side of the doorway, wherein the overall size of traffic or objects entering or exiting the protected area is identified by
monitoring which light beam receivers from the at least one plurality of light beam receivers do not receive a light beam;
monitoring the order in which each light beam receiver from the at least one plurality of light be receivers stops receiving a light beam occur; and
monitoring the duration each light beam receiver from the at least one plurality of light beam receivers fails to receive a light beam for.
13 . The method of claim 12 , further comprising the step of providing at least a second plurality of light beam emitters and at least a second plurality of light beam receivers on a second side of the doorway, wherein the overall size of traffic or objects entering and exiting the protected area is identified by
monitoring which light beam receivers from the first plurality of light beam receivers and the at least second plurality of light beam receivers do not receive a light beam;
monitoring the order in which each light beam receiver from the first plurality of light beam receivers and the at least second plurality of light beam receivers stops receiving a light beam occur; and
monitoring the duration each light beam receiver from the first plurality of light beam receivers and the second plurality of light beam receivers fails to receive a light beam for.
14 . The method of claim 13 , further comprising the steps of
comparing the overall size of traffic or objects identified entering the protected area to the overall size of traffic or objects shape identified exiting the protected area; and
controlling movement of the door panel based on the overall size of traffic or objects identified exiting the protected area to the overall size of traffic or objects identified entering the protected area.
15 . The method of claim 14 , further comprising the step of warning approaching traffic or objects of impending movement of the door panel.
16 . The method of claim 15 , further comprising the step of warning approaching traffic or objects that the door panel is moving.
17 . The method of claim 14 , further comprising the step of warning approaching traffic or objects that other traffic or objects have entered the protected zone.
18 . The method of claim 14 , wherein controlling the movement of the door panel is holding the door panel in an open position until the overall size of traffic or objects are detected exiting the protected area which matches the overall size of all traffic or objects detected entering the protected zone.
19 . The method of claim 14 , wherein controlling the movement of the door panel is closing the door panel at a rate slower than a normal closing rate until the overall size of traffic or objects is detected exiting the protected area which matches the overall size of all traffic or objects entering the protected zone.
20 . The method of claim 14 , further comprising the step of providing a visual warning once traffic or objects are detected entering the protected zone until traffic or objects having a matching overall size are detected exiting the protected zone.