APPARATUS AND METHODS FOR DETECTING DOOR CURTAIN DETACHMENT

Abstract

Methods, apparatus, systems, and manufactured articles for detecting door curtain detachment are described. An example apparatus described herein includes a sensor for detecting a side edge of a door curtain within a door guide, and a controller for identifying when the door curtain transitions from an operating state to a detachment state based on a signal from the sensor. The operating state corresponds to when the side edge of the door curtain is enclosed by the guide as the door curtain moves between the open and closed positions, and the detachment state corresponds to when a portion of the side edge of the door curtain that is below an upper end of the guide separates from the guide.

Description

APPARATUS AND METHODS FOR DETECTING DOOR CURTAIN DETACHMENT RELATED APPLICATIONS This patent claims priority over U.S. provisional patent application No. 62 / 897,790, filed on September 9, 2019, which is incorporated herein by reference in its entirety. FIELD OF DESCRIPTION This disclosure relates generally to curtain doors and, more particularly, to devices and methods for detecting curtain door detachment. BACKGROUND The curtains of detachable doors can be partially displaced when impacted from a direction not parallel to the curtain's travel direction. When a force sufficient to displace a curtain impacts the curtain of a detachable door, the curtain moves out of the vertical channel within which it normally travels. The detachable door can then restore the curtain to its normal operating state within the channel either through a manual feedback operation, such as a user repositioning the curtain within the channel, or through an automated feedback operation, such as pulling the curtain through a feedback mechanism. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a front view of an example door constructed according to the teachings described here. Fig. 2 is a perspective view of the upper left corner of the example door in Fig. 1. Fig. 3A is a detailed view of an example feedback roller assembly of the example gate in Fig. 1. Fig. 3B is a detailed view of the example feedback roller assembly illustrated in Fig. 3A, but with the door curtain in a fully open position. Fig. 4 is a cross-sectional view of the example feedback roller assembly of Fig. 1 taken along line 4-4. Fig. 5 is a cross-sectional view of the example feedback roller assembly of Fig. 1 taken by line 5-5, but with the door curtain in the operating state. MA / t / ZUZZ / UÓ4OO4 Fig. 6 is a front view of another example door similar to the example door in Fig. 1 but including a first example door curtain detachment detection system. Fig. 7A is a front view of another example feedback roller assembly similar to the feedback roller assembly in Figs. 3A-3B, but including a second example door curtain detachment detection system. Fig. 7B is a front view of another configuration of the second example door curtain detachment detection system of Fig. 7A. Fig. 8 is a cross-sectional view taken along line 8-8 of Fig. 5 showing a third example door curtain detachment detection system installed within an example guide of an example door similar to the door in Fig. 1. Fig. 9 is a front view of an example feedback roller assembly similar to the feedback roller assembly in Figs. 3A-3B, but including a fourth example door curtain detachment detection system. Fig. 10A is a partial view of an example door similar to the example door in Fig. 1, but including a fifth example door curtain detachment detection system. Fig. 10B is a cross-sectional view taken along line BB of Fig. 10A. Fig. 10C is an alternative example alignment feature for use in the example door curtain detachment detection system of Fig. 10A and 10B with an alternative sensor type. Fig. 11A is a partial view of an example door similar to the example door in Fig. 10A but including a sixth example door curtain detachment detection system. Fig. 11B is a cross-sectional view taken along line BB of Fig. 11A. Fig. 11C is an alternative example door curtain detachment detection system similar to Fig. 11B, but with a movable sensor. Fig. 12 is a partial view of an example door similar to the example door in Fig. 5 but including a seventh example door curtain detachment detection system. Fig. 13 is a view of an example feedback roller assembly similar to the feedback roller assembly in Fig. 5, but including an eighth ML / t / ¿U¿Z / UÓ4OO4 Example door curtain detachment detection system with an illustrated example curtain door in a detached position. Fig. 14 is a block diagram that illustrates an example implementation of any of the example controllers in Figs. 1, 6 and / or 10A. Fig. 15 is a representative flowchart of example machine-readable instructions that can be executed to implement the example controller of Fig. 14 to detect a door curtain detachment event using the first door curtain detachment detection system of Fig. 6. Fig. 16 is a representative flowchart of example machine-readable instructions that can be executed to implement the example controller of Fig. 14 to detect a door curtain detachment event using the second door curtain detachment detection system of Fig. 7A and / or 7B. Fig. 17 is a representative flowchart of example machine-readable instructions that can be executed to implement the example controller of Fig. 14 to detect a door curtain detachment event using the third door curtain detachment detection system of Fig. 8. Fig. 18 is a representative flowchart of example machine-readable instructions that can be executed to implement the example controller of Fig. 14 to detect a door curtain detachment event using the fourth door curtain detachment detection system of Fig. 9. Fig. 19 is a representative flowchart of example machine-readable instructions that can be executed to implement the example controller of Fig. 14 to detect a door curtain detachment event using the fifth door curtain detachment detection system of Fig. 10A. Fig. 20 is a representative flowchart of example machine-readable instructions that can be executed to implement the example controller of Fig. 14 to detect a door curtain detachment event using the eighth door curtain detachment detection system of Fig. 13. Figure 21 is a representative flowchart of example machine-readable instructions that can be executed to implement the example controller in Figure 14 to analyze detachment event data and trigger adjustments based on the analysis of detachment event data. Fig. 22 is a block diagram of an example processor platform structured to execute the example machine-readable instructions of Figs. 15-21 to implement the example controller of Fig. 14. The figures are not to scale. Instead, the thickness of layers or regions may be enlarged on the drawings. In general, the same reference numbers will be used on all drawings and in the accompanying written description to refer to identical or similar parts. The descriptors first, second, third, etc., are used here to identify multiple elements or components that may be referenced separately. Unless otherwise specified or understood from the context of use, such descriptors are not intended to imply any meaning of priority or order in time, but are simply labels to refer to multiple elements or components separately for ease of understanding of the disclosed examples. In some examples, the descriptor “first” may be used to refer to an element in the detailed description, while the same element may be mentioned in a claim with a different descriptor, such as “second” or “third.” In such cases, it should be understood that these descriptors are used simply to facilitate reference to multiple elements or components. DETAILED DESCRIPTION Detachable doors provide a fail-safe mechanism for automatic door operation. If an automatic door fails to move (or does not move quickly enough) from a closed to an open position when a vehicle or person approaches, an impact on the door caused by the vehicle and / or person colliding with the detachable door curtain may cause the curtain to move from its normal position (e.g., into a detached state) to reduce (e.g., prevent) damage to the vehicle and / or the curtain and / or to reduce (e.g., prevent) injury to the person. However, repeated impacts on a detachable door curtain may result in eventual damage to the curtain and / or other components associated with the detachable door. Improper use and / or configuration of the drop-away door can exacerbate damage to the door curtain. For example, if a user repeatedly strikes the door curtain relying on its ability to drop away from its normal position, the door curtain and / or other components of the drop-away door may experience greater wear than if the user attempts to avoid impacts by using the drop-away design simply as a safety mechanism. Similarly, if the drop-away door is not configured correctly (for example, if the position of the trigger sensors is incorrect) to ensure proper activation of the door curtain, damage may occur. If the door curtain is incorrect (if the activation time is incorrect, if the amount of time the door remains open is incorrect, etc.), components can be damaged due to wear and tear. Such wear and tear can lead to excessive warranty claims at the manufacturer's expense. With conventional detachable doors, without a person visually monitoring the operation of the detachable door, the owner of a detachable door and / or the manufacturer of the detachable door may not be able to determine the extent of a door curtain detachment event that occurs. A door curtain detachment event occurs when at least a portion of one of the side edges of the door curtain comes out of a vertical guide within which the side edge of the door curtain travels during the opening and closing of the door curtain under normal operating conditions. The example methods, apparatus, systems, and manufactured articles (e.g., physical storage media) described herein enable the detection of door curtain detachment events to allow for adjustments, alerts, and / or corrective actions to address potential problems with a detachable door. In some examples of methods, apparatus, systems, and manufactured articles described herein, one or more sensors are structured to detect a force applied to a feedback roller of a detachable door, indicating that a detachment event has occurred. In some examples of methods, apparatus, systems, and manufactured articles described herein, one or more sensors are used in a detachable door guide to detect the presence of the door curtain within the guide.In some of these examples, the door curtain may include an easily detectable component traveling within the guide (e.g., an RFID tag, a metallic feature, etc.). In some of the example methods, devices, systems, and manufactured items described here, one or more switches directly connect the door curtain within the guide to determine its presence. In some examples, the presence of the door curtain within the guide can be used in conjunction with a known position of the door curtain (e.g., a closed position, an open position, or an intermediate position between open and closed) to detect door curtain detachment events.In some examples of manufacturing methods, apparatus, systems, and articles described herein, a conductive feature (e.g., a conductive sphere including a metallic outer layer, a conductive solid sphere, etc.) in the door curtain completes a circuit when it makes contact with the feedback rollers, thus indicating a feedback operation, further indicating that the curtain was in a detachment state. MA / t / ZUZZ / UÓ4OO4 Examples of manufacturing methods, devices, systems, and articles disclosed herein analyze data associated with door curtain detachment events to generate detachment event alerts. In some examples, a sample detachment alert generator communicates alerts to maintenance personnel, a manufacturer, and / or another entity. In some examples of manufacturing methods, devices, systems, and articles disclosed herein, door curtain detachment event data can be used to identify potential misalignment features in the door curtain and, in some examples, to issue maintenance requests. In some examples, door curtain detachment event data can be analyzed to determine a specific impact location that caused the door curtain detachment event. Examples of methods, devices, systems, and manufactured items described here utilize door curtain detachment event data analysis to enable corrective action aimed at reducing the likelihood of future door curtain detachment events. In some examples, the position of the actuator sensor is adjusted to better detect approaching vehicles and / or people. In some examples, the timing associated with an actuator sensor is adjusted to allow for faster door curtain actuation. In some examples, the amount of time the door remains open is adjusted to account for specific behaviors, such as two or more vehicles and / or people repeatedly passing through the entrance in succession. Figure 1 is a front view of an example door 102 constructed according to the teachings described herein. The illustrated example door 102 includes an example curtain door 104, which is movable vertically between an open and a closed position. The illustrated example door 102 includes an example drive tube 106, which includes a horizontal shaft around which the door curtain 104 rotates when the door curtain 104 is actuated to move between the open and closed positions. When the door curtain 104 is moved to an open position, it is at least partially stored within an example curtain door retainer 108. Figure 2 includes a perspective view of the door curtain retainer 108, which illustrates an example of a curved slot 202 occupied by the door curtain 104 when it is open (e.g., retracted). The curtain door 104 in the illustrated example extends between the example rails or guides 110. Specifically, the curtain door 104 in the illustrated example extends laterally between the guides 110, with the opposite side edges 116 of the curtain door 104 retained within the guides 110 during normal operation to maintain the blocking of an example entrance 112 when the curtain door 104 is in a closed position. The curtain door 104 has a lower edge, as shown in example 105. In some examples, the guides 110 also serve to retain the side edges 116 of the curtain door 104 as the curtain moves between the open and closed positions during normal operation. However, the door curtain 104 can be displaced by an impact in a direction not parallel to the door curtain 104 so that the edges of the door curtain 104 come out or detach from one or more of the guides 110.In some examples, the impact may cause door curtain 104 to detach from only one of the guides (e.g., the left or right guide), while in other examples, the impact may cause door curtain 104 to detach from both guides 110. For example, if a person and / or object (e.g., a vehicle such as a forklift) impacts door curtain 104 in a direction not parallel to the door curtain 104, the force of the impact may cause the door curtain 104 to detach from the guide, thus reducing the likelihood of injury to the person and / or damage to the object. Allowing door curtain 104 to detach in this manner may also reduce the likelihood of damage to door curtain 104 and / or other components of example door 102.In some examples, door 102 is an automated door, so that when a person and / or vehicle approaches the door, one or more sensors send feedback signals to an example controller 114 indicating the approach of the person and / or vehicle. In some of these examples, controller 114 causes door curtain 104 to move to the open position in response to the sensor feedback to unlock entrance 112 and allow the person and / or vehicle (and / or other traffic) to pass. However, even in examples where door activation is automatic, delayed activation, failure to activate (for example, due to faulty sensors), and / or other factors can cause people and / or objects to impact door curtain 104. The controller 114 in the illustrated example provides commands to the components of door 102 (e.g., a motor, an actuator, etc.) to cause the door curtain 104 to move to the open position or extend to the closed position in response to signals from one or more sensors and / or commands issued by an operator. The controller 114 in the illustrated example receives signals from one or more sensors associated with door 102 that enable the detection of a door curtain drop event, corresponding to door curtain 104 entering a drop state. In some examples, the controller 114 analyzes the drop event data from MA / t / ZUZZ / UÓ-TOO^ door curtain to generate reports on door curtain detachment events, provide recommendations to rectify a cause of door curtain detachment events, trigger adjustments to one or more actuators and / or sensors, issue maintenance alerts, and / or take other actions based on the analysis of door curtain detachment event data. Further detail of the controller 114 structure is illustrated and described in relation to Fig. 14, and the techniques implemented by the controller 114 are illustrated and described in relation to Figs. 15-21. As used herein, when the door curtain 104 is struck with sufficient force to cause the edges of the door curtain 104 to come out through one or more of the guides 110, the door is said to be in a “detachment state.” As used herein, when the door curtain 104 is held by the guides 110 during normal operation, the door curtain 104 is in an operational state. In the illustrated example in Fig. 1, the door curtain 104 has entered a detachment state because a portion of the door curtain 104 comes out through the guide 110 on the left side (as seen on the page) of the example door 102. In particular, when a portion of the door curtain 104 below an upper end of the guide 110 separates from the guide 110, the door curtain 104 has entered a detachment state. A side edge 116 of the door curtain 104 in the illustrated example is partially visible, as one of the guides 110 has been removed from the left side. Side edge 116 is one of the two side edges of the door curtain 104. The second side edge is on the right side of the door curtain 104, opposite side edge 116 on the left side, as seen in Fig. 1, but this second side edge is concealed within the corresponding guide 110 in Fig. 1. As used here, side edge 116 refers to either side edge (e.g., the left or right side edge) of the door curtain 104. In this example, both side edges 116 are substantially identical. Therefore, while only one of the side edges 116 is shown, both side edges 116 include a plurality of alignment features of Example 118.The example alignment features 118 are protrusions extending from the door curtain 104 that help retain the side edges 116 of the door curtain in the guides 110. The example alignment features 118 in the illustrated example are generally spherical in shape, although alignment features 118 can have any type of shape and / or any combination of shapes (e.g., different alignment features 118 can have different geometries). When door curtain 104 moves to the detached state, it is It is important that the door curtain 104 be restored to its operating state (for example, by restoring the side edge 116 of the door curtain, which was forced out of one of the guides 110, to its retained position within the corresponding guides 110). If the side edge 116 of the door becomes disengaged from one of the guides 110 while the door curtain 104 is moving between the open and closed positions, the door curtain 104, one of the guides 110, and / or other components of door 102 may be damaged due to wear. To prevent this, door 102 includes example feedback roller assemblies 120 attached near the top of the guides 110. The feedback roller assemblies 120 of the illustrated example in Fig. 1 include a plurality of feedback rollers 122 arranged in alignment along the path of the door curtain 104 in a direction extending away from the guides 110.When the door curtain 104 is in a detached state and the controller 114 causes the door curtain 104 to move to the open position, the alignment features 118 on the door curtain 104 that are outside the guide 110 will contact one or more of the feedback rollers 122 and be forced to realign with the corresponding guide 110, thereby restoring the door curtain 104 to the operating state. Details of the feedback roller assemblies 120 of Fig. 1 are illustrated and described in conjunction with Figs. 2, 3A, 3B, and 4 below. Fig. 2 is a perspective view of the upper left corner of the example door 102 in Fig. 1. The perspective view in Fig. 2 illustrates three example feedback rollers 122a, 122b, and 122c from one of the feedback roller assemblies 120. In some instances, the construction and operation of the two feedback roller assemblies 120 are substantially identical. Accordingly, although the following discussion is provided with regard to the feedback roller assembly 120 shown in Fig. 2, the discussion applies similarly to the other feedback roller assembly 120 of Fig. 1 that is not shown in the detailed perspective view of Fig. 2. The three feedback rollers 122a, 122b, 122c of the feedback roller assembly 120 in Fig. 2 are vertically separated. In the illustrated example, the feedback roller assembly 120 includes three feedback rollers 122a, 122b, 122c on one side of the door curtain 104, and three feedback rollers 122d, 122e, 122f (Fig. 3B) on the other side of the door curtain 104. For comparison, Fig. 3A illustrates a detailed view of an example feedback roller assembly 120 of the example door 102 in Fig. 1 with the door curtain in the closed position, while Fig. 3B is a detailed view of the example feedback roller assembly 120 illustrated in Fig. 1. 3A, but with door curtain 104 in a fully open position. ML / t / ZUZZ / UÓ^OÍW In Fig. 3B, the six feedback rollers 122a, 122b, 122c, 122d, 122e, and 122f are visible. The curtain door 104 moves vertically in the guide 110 and travels between pairs of feedback rollers 122. For example, the first feedback roller 122a and the fourth feedback roller 122d act as a first pair, the second feedback roller 122b and the fifth feedback roller 122e act as a second pair, and the third feedback roller 122c and the sixth feedback roller 122f act as a third pair. For the purposes of explanation and brevity, as used herein, feedback roller 122 may refer to any of feedback rollers 122a, 122b, 122c, 122d, 122e, 122f, and “feedback rollers 122” may refer to any grouping of feedback rollers 122a, 122b, 122c, 122d, 122e, 122f. The feedback rollers 122 in the illustrated example are shaped such that when one of the alignment features 118 contacts one of the feedback rollers 122 during a feedback operation as the door curtain 104 opens, the alignment feature 118 is forced inward and moves into vertical alignment with the guide 110. The feedback rollers 122 in the illustrated example are capable of moving (e.g., translating and / or rotating) in response to a force from one of the alignment features 118. In the illustrated example, several pairs of feedback rollers 122 are present to capture the alignment feature 118 and maintain the door curtain 104 within the guide 110.When in an operational state (for example, when the door curtain 104 is not in the detachment state), the feedback rollers 122 are separate from the alignment features 118 because the alignment features 118 are retained within the guides 110. In some examples, the feedback roller assembly 120 may include additional pairs of feedback rollers 122. In other examples, the feedback roller assembly 120 may include fewer than three pairs of feedback rollers 122. The feedback rollers 122 are mounted on the first and second example feedback blocks 124a, 124b, which are connected to an example frame 126 of door 102. The feedback blocks 124a, 124b of the illustrated example are mounted directly above the guide 110. In the illustrated example, the guide 110 is also attached to the frame 126 of door 102. Fig. 4 is a cross-sectional view of the example feedback roller assembly 122 of Fig. 2 taken along line 4-4 shown in Fig. 1. As illustrated in Fig. 4, the alignment features 118 of the door curtain 104 are retained behind (for example, to the left of, in the view of Fig. 4.) the feedback rollers 122b, 122e and the guide 110 which is aligned with the MA / t / ZUZZ / UÓ^OÍW feedback rollers. The feedback rollers 122 of the illustrated example make direct contact with the alignment features 118 during a feedback operation. The feedback roller pairs (e.g., feedback rollers 122b, 122e) in the illustrated example are positioned so that the alignment feature 118 cannot fit directly between the feedback rollers 122b, 122e and therefore, when the alignment feature 118 is forced upwards towards the top of the door 102 (e.g., due to the force of a motor) during the opening of the door curtain 104, the feedback rollers 122 force the alignment feature 118 to realign itself vertically with the guide 110 to return the door curtain 104 to a normal operating state.The feedback rollers 122 are directly connected to the feedback blocks 124a, 124b. In some examples, the feedback rollers 122 may have a different geometry that equally allows the alignment characteristics 118 to be restored within the guide 110. Fig. 5 is a cross-sectional view of the example 120 feedback roller assembly of Fig. 1 taken along line 5-5, but with the door curtain in the operating state, as opposed to the detached state illustrated in Fig. 1. 5, the door curtain 104 is in the operating state, as alignment features 118 are behind the feedback rollers 122, and the side edge 116 of the door curtain is retained within the guide 110. The guide 110 includes example retaining strips 128 on each side of the door curtain 104 to help retain the side edge 116 of the door curtain 104 within the guide 110. In the illustrated example, the retaining strips 128 extend inward into the door curtain 104 with a gap between them sized to be greater than the thickness of the door curtain 104.In this way, the door curtain 104 can move freely between the open and closed positions along the space between the retaining strips 128. However, the space is sized to be smaller than the alignment feature 118 to retain the alignment feature 118 within the guide 110 as the door curtain 104 moves in the normal operating state. In some instances, the retaining strips 128 are flexible to allow the alignment feature 118 to pass through the space between the strips 128 when sufficient force is applied. That is, if a relatively small force is applied to the door curtain 104 (for example, a force of 0.9071 kg (two pounds) applied perpendicularly to the door curtain 104), the alignment feature 118 may interfere with or engage the retaining strips 128, but remain within the guide 110.However, if a relatively larger force (e.g., a force of 2.26796 kg (five pounds), a force of 4.5359 kg (ten pounds), etc.) is applied perpendicular to the door curtain 104, the retaining strips 128 can flex to allow the alignment features 118 to move out of alignment with the guide 110 and allow the door curtain 104 to enter the detachment state. In the illustrated example in Fig. 5, the alignment features 118 are distributed at uniform spacing along the side edge 116 of the door curtain 104. In some examples, the alignment features 118 may be spaced at irregular intervals. In some examples, the positioning of the alignment features 118 is not consistent along a length of the side edge 116 of the door curtain. The alignment features 118 may include any material. In some examples described here, the alignment features 118 are partially and / or fully conductive. In some examples described here, the alignment features 118 include a magnetic material. Examples of methods, apparatus, systems, and articles of manufacture (e.g., physical storage media) described herein include one or more detection systems for determining when the door curtain 104 enters the detachment state, or transitions from the detachment state to the operating state (e.g., during a feedback operation). Figure 6 is a front view of another example door 602 similar to example door 102 in Figure 1, but including a first example door curtain detachment detection system. The first example door curtain detachment detection system includes example tags 604 affixed to the side edges 116 of the door curtain 104. The tags 604 in the illustrated example are positioned alternately with the alignment features 118 along the side edges 116. Any number of tags 604 can be positioned on the side edge 116 of the door curtain 104 to detect the presence of the door curtain 104 in the guide 110. Therefore, in some examples, more than one alignment feature 118 can be located between adjacent tags 604. In some examples, each of the side edges 116 includes only one tag 604.In some of these examples, the unique tag 604 is located near a lower or front edge of the door curtain 104 because the lower corner of the door curtain 104 is often the part of the curtain most likely to be forced out of the guide 110 due to an impact with the curtain. In some examples, the tags 604 may be integrated into or an integral part of the alignment features 118. The 604 tags in the illustrated example are radio frequency identification (RFID) tags. In some examples, the tags are Bluetooth Low Energy (BLE) tags, optical tags (e.g., barcodes, quick response (QR) codes, optical recognition symbols, etc.), or any other type of tag to enable detection of the side edges 116 of the door curtain 104 remaining within the corresponding guides 110. The first door curtain detachment detection system includes example scanners 606a and 606b. The scanners 606a and 606b in the illustrated example are mounted on guide 110 to detect the door curtain 104 within guide 110. While two scanners 606a and 606b are illustrated for simplicity in Fig. 6, the door 602 can include any number of scanners on either of the guides 110 (the one on the right side of the guides 110 can also include scanners). For example, in some examples, only one scanner can be placed on each side of the door curtain 104. In other examples, three or more scanners can be placed on only one side of the door curtain 104. In some examples, there may be more scanners associated with one side edge 116 of the door curtain 104 than with the other side edge.The example scanners 606a and 606b in the illustrated example are capable of detecting the 604 tags when the 604 tags are near the scanners 606a and 606b (e.g., within 12.7 cm (five inches), within 25.4 cm (ten inches), etc.). For example, the scanners 606a and 606b can be oriented toward the inside of the guide 110 where the side edge 116 of the door curtain 104 passes through the guide 110. The illustrated example includes the first scanner 606a on top of guide 110, which is useful for detecting the presence of door curtain 104 within guide 110 in a position directly below feedback roller assembly 120. If door curtain 104 moves to a fully open position (for example, where no part of door curtain 104 extends through door 112), then the entirety of door curtain 104 that extends below the position of scanner 606a when door curtain 104 is in the closed position will pass through scanner 606a during normal operation. Conversely, if any part of door curtain 104 separates from guide 110, that part of door curtain 104 will not be detected by scanner 606a when door curtain 104 moves from a closed to an open position.Based on the failure of scanner 606a to detect a portion of door curtain 104 when such detection is expected based on the curtain's position and movement, the detachment state can be detected. In some examples, door 602 may be configured for partially open operation. In some of these examples, door curtain 104 only opens to a partially open position. MA / t / ZUZZ / UÓ^OO^ (for example, where a portion of door curtain 104 remains extended across a first portion of entrance 112 while a second portion of entrance 112 is unobstructed), by door curtain 104). For example, a user may prefer the door to open only in a partially open position to accommodate pedestrian traffic, or if vehicles passing through the door are not expected to exceed a specific height. Utilizing this partially open position helps conserve the energy used by the motor to operate door curtain 104 and saves energy due to potential HVAC differences on either side of door curtain 104. If door 602 is to open door curtain 104 to the partially open position, it may be advantageous to use both the first scanner 606a and the second scanner 606b, where the second scanner 606b is mounted on the underside of the guide 110 (for example, below the height of the lower edge of door curtain 104 when it is in the partially open position) to detect a detachment state that occurs due to the separation of door curtain 104 from the guide 110 towards the lower edge of door curtain 104.In some of these examples, when the second scanner 606b communicates data to controller 114 and a detachment state is detected, controller 114 can cause door 602 to move to a fully open position to enable the alignment features 118 toward the bottom of the door curtain 104 to pass through the feedback roller assemblies 120 to restore the curtain to the normal operating state. If door 602 is to open the door curtain 104 to a partially open position, and only the first scanner 606a is used, toward the top of the guide 110, a detachment occurring toward the bottom of the door curtain 104 may not be detected. Therefore, one or more of the scanners 606a and 606b may be attached to the guide 110 to detect the detachment state based on the specific configuration of door 602.Any number of scanners can be used and in any position along the 110 guides. The scanners 606a and 606b in the illustrated example are RFID scanners. In some examples, scanners 606a and 606b are optical scanners, BLE scanners, and / or any other type of scanner suitable for detecting the 604 tags. Scanners 606a and 606b communicate data to controller 114 to enable controller 114 to determine whether door curtain 104 is in the operating state or the detachment state, and to determine the characteristics of the detachment state. For example, controller 114 can determine whether door curtain 104 is in the detachment state based on the door curtain's vertical position (e.g., as determined by the door curtain 104's motor and / or drive element) and data. MA / t / ZUZZ / UÓ-TOO^ of scanners 606a, 606b. For example, if it is known that door curtain 104 is approximately half open and is moving toward the fully open position, and the first scanner 606a has not detected tags 604 for a time limit (or for a threshold number of expected tags) during the door curtain movement, controller 114 may determine that door curtain 104 may be in the detachment state. Conversely, controller 114 will not indicate that door curtain 104 is in the detachment state in response to the second scanner 606b not detecting tags 604 during this movement because it is known that the bottom edge of door curtain 104 is above the second scanner 606b, so detection of tags 604 would not be expected.In some examples, if only a single 604 tag, or a small number of 604 tags, is not detected when it is expected to be detected (e.g., based on a position of the bottom edge of door curtain 104 and a known speed and direction of movement of door curtain 104), the controller 114 may determine that a maintenance alert should be issued to determine if one or more of the 604 tags are not operational or are missing. Furthermore, in some examples, the 604 tags are signaled to allow the decoding of location information corresponding to a vertical position of the 604 tags. For example, individual 604 tags, when detected by one of the 606a or 606b scanners, can communicate a vertical position of the detected 604 tags. If the controller 114 determines that a plurality of tags (e.g., a threshold number of tags) has not been detected in the positions that should have been passed by one of the 606a or 606b scanners, the controller 114 can determine that the door curtain 104 is in the detachment state. Similarly, the controller 114 can compare an elapsed movement time with a threshold time period during which the 604 tags are expected to be detected based on a known tag separation and a known speed of the door curtain 104 during operation.For example, if the door curtain is expected to pass through one of the scanners 606a, 606b, and one of the scanners 606a, 606b does not detect any of the 604 tags for a duration threshold, the controller can determine that the door curtain 104 is in the detachment state. Figure 7A is a front view of a second example feedback roller assembly 702a, similar to the feedback roller assembly 120 in Figures 3A-3B, but including a second example door curtain detachment detection system. The second door curtain detachment system includes MA / t / ZUZZ / UÓ-TOO^ example switches 704 to be coupled with rear portions of example 706 of support structure for the respective second feedback roller 122b and third feedback roller 122c. The first and second feedback rollers 122b, 122c are further connected to the support structure which includes center portions of example 708, which extend through the feedback block 124a and connect the respective feedback rollers 122a, 122b to the corresponding rear portions 706. The feedback block 124a includes cavities of example 710, which include springs of example 712 for diverting the feedback rollers 122 and the support structure connected to the feedback rollers 122 towards the switches 704. In a first example configuration of the second feedback roller assembly 702a illustrated in Fig. 7A, the cavities 710 are on an inner side of the feedback block 124a near the feedback rollers 122, and the springs 712 are compression springs to deflect the feedback rollers 122 to the right, as seen in the illustrated example. In a second example configuration of the second feedback roller assembly 702b illustrated in Fig. 7B, the cavities 710 are located on an outer side of the feedback block 124a near the rear portions 706 of the feedback rollers 122, and the springs 712 are tension springs for deflecting the feedback rollers 122 and the support structure is connected to the feedback rollers 122 on the right as seen in the illustrated example. In both the example of Fig. 7A and the example of Fig.7B, switches 704 are normally pressed (e.g., when a feedback operation is not occurring) due to the biasing force created by springs 712. However, when the door curtain 104 is being restored from a detached state, the alignment features 118 that were forced out of the guide 110 may engage one or more of the feedback rollers 122 and cause the feedback rollers to move in opposition to one or more of springs 712 until the corresponding switches 704 are no longer pressed. In some examples, switches 704 may be configured alternatively so that they are not activated (e.g., not pressed) when the door curtain 104 is in the normal operating state, and are activated during a feedback operation.In some examples, the switches 704 may be integrated within the feedback block 124a, or positioned on the opposite side of the feedback block 124a to couple the portions of the feedback rollers 122 that couple the alignment features 118. While only two of the three feedback rollers 122a, 122b, 122c ML / t / ZUZZ / UO4OO4 visible include switches 704; any number of feedback rollers 122 may include switches 704 to engage with the rear portions 706 of the feedback rollers 122. In some examples, the lowest of the feedback rollers 122 (for example, the third feedback roller 122c) is most likely to activate the alignment features 118 and is therefore monitored using one of the switches 704. In the illustrated examples in Figs. 7A and 7B, only the feedback rollers that are monitored by switches 704 include the rear portions 706. In some examples, any combination of the feedback rollers 122 includes the rear portions 706. The switches 704 are communicatively coupled to the controller 114 to provide the controller 114 with signals indicating whether the switches 704 are currently pressed or otherwise activated. The controller 114 can determine that a feedback operation has occurred (and therefore the door curtain 104 must have been in the detached state) when it changes one or more signals from one or more of the switches 704. For example, the signals might be a binary signal, where a “1” represents the switch being engaged (e.g., indicating that the roller is in its normal state, not moving during a feedback operation) and a “0” represents the switch not being engaged (e.g., indicating that the roller has moved during a feedback operation), or vice versa. In some examples, a proximity sensor and / or other sensor may be used in addition to or instead of the switches 704. Figure 8 is a cross-sectional view taken along line 8-8 of Figure 5 of a third example door curtain detachment detection system installed within guide 110 of an example door 802 similar to the door in Figure 1. The third door curtain detachment detection system is installed in guide 110 of door 802. Guide 110 includes retaining strips 128, an example open portion 804, and an example seal portion 806. The open portion 804 is a vertical channel in which the side edge 116 of door curtain 104 (including alignment features 118) moves during normal operation. Retaining strips 128 retain the side edge 116 of door curtain 104 within the open space of guide 110.The sealing portion 806 of the guide 110 provides a seal along the side edge 116 of the door curtain 104 to reduce airflow through the door 802 when the door curtain 104 is in the closed position. The sealing portion 806 is substantially parallel vertically (e.g., within 10 degrees) to the open portion 804. For example, the sealing portion 806 may be a seal (e.g., thermal insulation within the cavity of the guide 110) implemented to reduce costs. MA / t / ZUZZ / UÓ4OO4 heating and air conditioning energy if there is a thermal gradient between spaces separated by door 802. In the third door curtain detachment detection system, the example switches 808 are embedded (or installed in recesses) in the sealing portion 806 of the guide 110. The sealing portion 806 can include any number of switches 808. In the illustrated example, the switches 808 are evenly spaced along a vertical length of the sealing portion 806. In the illustrated example of Fig. 8. The switches 808 are spring-loaded and are pressed by the door curtain 104 when the door curtain 104 is in a vertical position corresponding to the respective switches 808. In some examples, a sensor (e.g., a proximity sensor) is used instead of the switches 808. In some examples, instead of embedding the switches 808 within the sealing portion 806, the switches 808 are mounted on an external surface of the sealing portion 806.That is, in some examples, the switches 808 are mounted on an example surface 810 of the sealing portion 806 of the guide 110 facing the open portion 804 of the guide 110. In some examples, the door 802 does not include the sealing portion 806. In some of these examples, the switches 808 are mounted on another surface of the guide 110. The switches 808 are communicatively coupled to the controller 114 to provide the controller 114 with signals indicating whether the switches 808 are pressed or otherwise activated. In some instances, the switches 808 communicate a binary signal (e.g., a 1 if the switch 808 is in a pressed position and a 0 if the switch 808 is in an extended position, or vice versa). The controller 114 can determine whether the door curtain 104 is on the guide 110 at a switch location based on a known vertical position of the door (e.g., determined by the motor or other drive element) and based on the signals from the switches 808 at known vertical heights. For example, if a switch is in a position above or equal to a position on the lower edge of the door curtain 104, the switch must be pressed if the door curtain 104 is in the operating state.If the switch signal indicates that it is not pressed (e.g., door curtain 104 is not present) in that position, then controller 114 can determine that door curtain 104 is in the detached state. Fig. 9 is a front view of an example 902 feedback roller assembly similar to the feedback roller assembly of Figs. 3A-3B, but including a fourth example door curtain detachment detection system. ML / t / ZUZZ / UÓ^OÍW The fourth door curtain detachment detection system includes an example sensor 904 to detect forces on and / or movement of the feedback block 124a. The sensor 904 in the illustrated example is an accelerometer. In some examples, sensor 904 is integrated into the feedback block 124a. Sensor 904 communicates data to controller 114 representing forces on and / or movement of the feedback block 124a. Controller 114 analyzes the data from sensor 904 to determine whether the forces and / or movement represented in the data are likely associated with a feedback operation. For example, controller 114 can recognize patterns during downstream processing that are associated with feedback operations.In some examples, controller 114 can be trained using a training dataset and can use machine learning techniques to identify features in the sensor 904 data that correspond to a feedback operation, as opposed to an impact on a door frame component 102, movement due to standard actuation of the door curtain 104, etc. In some examples, controller 114 can infer a detachment state based on the identification of a feedback operation. In some examples, door 102 includes one or more additional example sensors 906 to provide reference point data regarding forces and / or motion at door 102. For example, controller 114 can compare the forces and / or motion represented in the data from sensor 904 at feedback block 124a with forces and / or motion represented in data from one or more additional sensors 906 elsewhere on door 102. Although the additional sensor(s) 906 are / are located next to feedback block 124a, they may be located further away from feedback block 124a. If the forces and / or movement are exclusive to feedback block 124a, this may indicate a higher probability that a feedback operation has occurred, relative to the forces and / or movement experienced by another sensor elsewhere in door 102.In some examples, controller 114 can determine a portion of door curtain 104 that separated from guide 110 based on known positions of door curtain 104 and data from sensor 904. For example, if data from sensor 904 indicates that a feedback operation began when the bottom edge of door curtain 104 was at a specific height, controller 114 can determine that the portion of door curtain 104 extending from the specified height of the bottom edge of door curtain 104 until the feedback roller assembly 902 separated from guide 110. Fig. 10A is a partial view of an example door 1002 similar to the example door 102 in Fig. 1, but including a fifth example door curtain detachment detection system. The fifth example door curtain detachment detection system includes example sensors 1004 mounted along the guide 110. The sensors 1004 in the illustrated example are oriented toward the center of the guide 110 (e.g., where the side edge 116 of the door curtain 104 is positioned when in the normal operating state) to enable detection of the door curtain 104. The sensors 1004 in the illustrated example detect alignment features 118 on the side edge 116 of the curtain. Fig. 10B is a cross-sectional view taken along line BB in Fig.10A, which illustrates the sensor 1004 detecting one of the alignment features 118 on the side edge 116 of the door curtain 104 as the door curtain 104 moves through the guide 110. In some examples, the door 1002 includes only the upper part of the sensors 1004 illustrated in Fig. 10A. In some of these examples, the upper part of the sensors 1004 can detect a detachment event based on the absence of detection of the alignment features 118 as the door curtain 104 moves to the open position. In some examples, the controller 114 can determine a portion of the door curtain 104 that has detached from the guide 110 based on counting the alignment features 118 as they pass.For example, if there are twenty alignment features 118 along the entire length of the door curtain 104, and the sensors 1004 do not detect the lower ten alignment features 118 when the door curtain 104 moves to the fully open position, it can be determined that the portion of the door corresponding to the lower ten alignment features (e.g., the lower half of the door curtain 104, if the alignment features are evenly distributed vertically) has separated from the guide 110. In some instances, due to the presence of multiple sensors 1004, a portion of the door curtain 104 that has separated from the guide 110 can be determined before the door curtain 104 moves to the fully open position.In some of these examples, the position of the lower edge of door curtain 104 can be determined when the door curtain portion 104 has separated from the guide 110, based on data from sensors 1004 and known locations (e.g., lateral positions along the guide 110) of sensors 1004. In some examples, the alignment features 118 are conductive. In some of these examples, sensors 1004 are inductive proximity sensors for detecting the conductive material in the alignment features 118. In some examples, door curtain 104 may include conductive material independent of the alignment features 118 that is detected by sensors 1004.In some of these examples, only a lower portion of the alignment feature 118 may be conductive, and therefore the inductive sensor can determine whether the door curtain 104 entered a detachment state (since the lower portion of the door curtain 104 will be removed from the guide 110 regardless of the height at which the detachment event starts), but the data may not indicate the portion of the door curtain 104 that detached from the guide 110. In some examples, the sensors 1004 are capacitive sensors (e.g., a capacitive proximity sensor) or ultrasonic proximity switches (e.g., an ultrasonic proximity sensor). In some such examples, the sensors 1004 are capable of detecting non-conductive alignment features (e.g., made of plastic, nylon, etc.). In some examples where the sensors 1004 are ultrasonic sensors, they can measure a distance between one of the sensors 1004 and an object (e.g., the door curtain 104). The controller 114 can then determine whether this separation distance satisfies a threshold range associated with the door curtain 104 being within the guide 110. In some examples, the sensors 1004 are Hall sensors (e.g., reed switches), and one or more of the alignment features 118 include magnetic material. For example, Fig.Figure 10C illustrates an example of an alternative design for an alignment feature 118c, with a portion of the alignment feature 118c including magnetic material to be detected by the Hall sensor(s). In some examples, only a portion of the alignment feature 118c includes the magnetic material, as the lower edge of the door curtain 104 will necessarily be removed from the guide 110 during any transition to the detachment state. In some examples, the door curtain 104 may include magnetic material separate from the alignment feature 118, which is detected by a Hall sensor. In some examples, one or more of the 1004 sensors may be installed and / or connected to the feedback block 124a. In some of these examples, one or more of the 1004 sensors are microelectromechanical systems (MEMS) magnetometer sensors for detecting ferrous materials embedded in the alignment features 118 and / or other locations in the door curtain 104. In some of these examples, the MEMS magnetometer sensors can determine the position of one or more ferrous material locations based on the magnetic field strength on three axes, which can be used to determine if the ferrous material locations are outside the guide 110. In some examples, if the 1004 sensors include one or more MEMS magnetometer sensors, the 1004 sensors can detect when a vehicle passes through door 112.The one or more sensors 1004 of door 1002 communicate signals indicating the presence of one or more of the alignment features 118 or other locations containing ferrous materials (and therefore the presence of the door curtain 104) to allow the controller 114 to analyze transitions to the peel state (“peel events”) and implement corrective actions to address a cause of the peel state transitions. Fig. 11A is a partial view of an example door 1102 similar to the example door 1002 in Fig. 10A, but including a sixth example door curtain detachment detection system. Unlike the example illustrated in Fig. 10A, the sixth example door curtain detachment detection system shown in Fig. 11A includes one or more example sensors 1104 mounted along the guide 110 to detect one or more metal features 1106 coupled to the outer edge 1108 of the side edge 116 of the door curtain 104. In the illustrated example, the metal features 1106 are spaced twice as far apart as the alignment features 118. However, in other examples, the metal features 1106 may be spaced more or less far apart than shown in Fig. 11A.In some examples, only one metal feature 1106 is provided along the entire length of the door curtain 104 near the bottom edge, as this is the most likely location for removal from the guide 110 during a detachment, as shown in the illustrated example. In some examples, as detailed in Fig. 11B, the metal feature 1106 is a clip or other similarly shaped element that extends around the outer edge 1108 of the door curtain to interact with the front and rear surfaces of the door curtain 104. In other examples, the metal feature 1106 is attached (for example, by means of an adhesive or other fastening method) only to the outermost edge 1108 of the door curtain 104. In still other examples, the metal feature may be embedded within the door curtain 104 so that it does not extend beyond the outer edge 1108 of the door curtain 104. In the illustrated example, only one sensor 1104 is shown positioned near the top of the guide 110. However, in other examples, multiple sensors 110 can be positioned at different heights along the guide 110 (for example, similarly to the sensors 1004 shown in Fig. 10A). As more clearly shown in the cross-sectional view of Fig. 11B, sensor 1104 is attached to the rear wall of the guide opposite the opening through which the door curtain 104 extends during normal operation and where the retaining strips 128 are located. In some examples, sensor 1104 is an inductive proximity sensor. The example sensor 1104 in Fig. Sensor 11 is positioned to detect when a metallic feature 1106 is near (e.g., passes) sensor 1104. When sensor 1104 detects the metallic feature 1106, sensor 1104 generates and transmits a signal to controller 114.Therefore, controller 114 can detect a detachment event based on the absence of detection of one of the metallic features 1106 when the door curtain 104 moves to the open position because the metallic feature 1106 will be outside the guide 110 and out of the detection range of sensor 1104. Figure 11C is an alternative example door curtain detachment detection system similar to Figure 11B, but with a movable sensor 1104. More specifically, in some examples, the sensor 1104 is coupled to a biasing element 1110 (e.g., a spring) that drives the sensor 1104 toward the door curtain 104. In some examples, the sensor 1104 is part of an assembly that directly couples to the outer edge 1108 of the door curtain 104 and / or the metallic feature(s) 1106 on the door curtain 104. In some of these examples, the sensor assembly includes a low-friction surface and / or a roller 1112 (as shown in Figure 11C) to reduce wear caused by contact between the door curtain 104 and the sensor assembly. Enable the movement of sensor 1104 with respect to guide 110 as shown in the illustrated example in fig.11C allows the sensor 1104 to be closer to the metallic features 1106 and therefore smaller and / or with a shorter detection range than would be possible for the fixed-position sensor 1104 shown in Fig. 11B. Furthermore, the motion sensor 1104 of Fig. 11C enables the sensor to move with the movement of the door curtain 104. For example, the alignment features 118 on the door curtain 104 may be pushed toward the retaining strips 128 by wind force on the door curtain 104. While such forces may be insufficient to cause a detachment event, they may nevertheless pull the outer edge 1108 of the door curtain 104 away from the sensor 1104 of Fig. 11B. However, due to the polarizing element 1110 of Fig. 11C, sensor 1104 of fig.11C moves with the door curtain 104 to maintain a relatively constant distance from the outer edge 1108 of the door curtain 104 to detect the metallic feature 1106 as it passes during a door opening operation. The particular shape of the cross-section of guide 110 shown in figs. 11B and 11C is provided for illustrative purposes only. Likewise, the shape of the The cross-section of guide 110 shown in Fig. 4, which differs from the cross-sectional shape shown in Figs. 11B and 11C, is also provided for illustrative purposes only. More generally, guide 110 can be constructed with any suitable cross-sectional shape. Similarly, the retaining strips 128 can have any suitable shape according to the shape of guide 110 and / or the shape (e.g., thickness of the door curtain 104). Figure 12 is a partial view of an example door 1202 similar to the example door 102 of Figure 1 as detailed in Figure 5, but including a seventh example door curtain detachment detection system. In the illustrated example, a photoelectric sensor 1204 comprising the first and second parts 1206, 1208 is positioned within the feedback blocks 124a, 124b beneath the feedback rollers 122. More particularly, in some examples, the first and second parts 1206, 1208 of the photoelectric sensor 1204 are positioned to transmit a light beam 1210 (e.g., infrared light, visible light, ultraviolet light, etc.) through the curtain door path 104 during normal operation.In the illustrated example, the photoelectric sensor 1204 is a retroreflective optical sensor in which the first part 1206 generates the light beam 1210 and detects the light beam after it is reflected by the second part 1208, corresponding to any suitable reflective surface. When the light beam 1210 is detected by the first part 1206, a signal is generated and sent to the controller 114. In other examples, either part 1206 or 1208 of the photoelectric sensor 1204 generates the light beam 1210, and the other part 1206 or 1208 detects the light beam and provides an associated signal to the controller 114. In some examples, the door curtain 104 includes and / or carries a reflective surface along its side edge 116 to serve as the second portion 1208 when the first portion 1206 corresponds to a retroreflective optical sensor.In some of these examples, the reflective surface on the door curtain 104 is positioned along the side edge 116 in a location that aligns with the retroreflective optical sensor when the door curtain 104 is in the normal operating state within the guide 110. In such examples, the first part 1206 detects the light beam 1210 when the door curtain 104 is in the normal operating state and generates a signal (indicative of a detachment state) that is provided to the controller 114 when the light beam 1210 is not detected. During normal operation, the door curtain 104 will block the path of the light beam 1210 between the first and second parts 1206, 1208 of the photoelectric sensor 1204 so that no signal will be generated or sent to the controller 114. However, during a detachment event when at least a portion of the MA / t / ZUZZ / UÓ^OÍW If the side edge 116 of the door curtain 104 has been forcibly removed from the guide 110, the door curtain 104 will not block the light beam 1210, thus allowing the controller 114 to detect the detachment event. In some examples, the first and second parts 1206, 1208 of the photoelectric sensor 1204 are positioned inside the guide 110, near the top and just below the feedback blocks 124a, 124b. Additionally, in some examples, multiple photoelectric sensors 1204 can be positioned at different locations along the guide 110. Figure 13 is a view of an example feedback roller assembly 1302 similar to the feedback roller assembly 120 of Figure 5, but including an eighth example door curtain detachment detection system with the door curtain 104 illustrated in the detached state. The door curtain 104 is illustrated in the detached state as indicated by one of the alignment features 118 in front of the lower pair of feedback rollers 122c, 122f, which indicates that the side edge of the door curtain 104 is not aligned with the guide 110 in the vertical position of the lower pair of feedback rollers 122c, 122f. In the eighth door curtain detachment detection system, both alignment features 118 and feedback rollers 122 are electrically conductive. The eighth door curtain detachment detection system includes an example input power supply 1304 and an example electrical circuit 1306 for connecting the input power supply 1304 to the controller via a pair of feedback rollers 122. When one of the alignment features 118 is activated, the feedback rollers 122 are in contact, thus closing the electrical circuit. For example, in the illustrated example in Fig. 13, a feedback operation is taking place, in which one of the alignment features 118 is in contact with feedback rollers 122c and 122f.As a result, an electrical signal flows from the input power supply 1304 through the electrical circuit via the feedback rollers 122c, 122f, and the alignment feature 118, contacting the feedback rollers 122c, 122f, and finally reaching the controller 114. When the controller 114 receives a signal from the electrical circuit 1306, it can determine that a feedback operation occurred (and therefore, the door curtain 104 was previously in the detached state). In some instances, all the alignment feature 118 is electrically conductive.In some examples, only one or a relatively small number (e.g., two, three) of the alignment features 118 toward the bottom of the door curtain 104 are electrically conductive, since these features will likely be involved in the feedback operation if the door curtain 104 is in a detached state. Furthermore, while the second pair of feedback rollers 122b, 122e and the third pair of feedback rollers 122c, 122f are connected to the electrical circuit 1306 in the illustrated example, any one or more pairs of the feedback rollers 122 may be connected to the electrical circuit 1306. In some examples, the input power supply 1304 is a direct current (DC) power supply. In some examples, the input power supply 1304 is an alternating current (AC) power supply and uses an AC / DC converter. In the illustrated example, the electrical circuit 1306 includes one or more resistors to prevent current overload when one of the alignment features 118 closes the circuit. Although each of the different example door curtain detachment detection systems discussed in relation to Figs. 6-13 have been described individually, in some examples, more than one of the detection systems and / or particular aspects of different detection systems may be combined in any manner suitable for redundancy and / or to provide more robustness and / or accurate detection of detachment events. Figure 14 is a block diagram illustrating an example implementation of controller 114 from Figures 1, 6, 10A, and 11A. Example controller 114 includes an example sensor data analyzer (1402), an example door position monitor (1404), an example maintenance alert generator (1406), an example detachment alert generator (1408), an example detachment alert analyzer (1410), an example report generator (1412), an example door drive adjuster (1414), and an example door movement adjuster (1416). The sensor data analyzer 1402 in the illustrated example of Fig. 14 analyzes sensor data from one or more of the scanners 606 in Fig. 6, the switches 704 in Fig. 7, the switches 808 in Fig. 8, the sensors 904 in Fig. 9, the sensors 1004 in Fig. 10A, the sensor 1104 in Fig. 11A, the photoelectric sensor 1204 in Fig. 12, and / or the electrical circuit 1306 in Fig. 13. In some examples, the sensor data analyzer 1402 in the illustrated example interprets the sensor signals to determine whether the door curtain 104 was present in a location adjacent to one of the sensing devices and / or whether a feedback operation occurred. In some examples, this analysis can be the basis for inferring or determining that a detachment event has occurred. MA / t / ZUZZ / UÓ^OÍW The sensor data analyzer 1402 in the illustrated example determines a feedback operation that occurred in response to a change in the signal (e.g., from a “0” to a “1” if the signal is a binary signal, from a “1” to a “0”, etc.) from one or more of the switches 704 in Fig. 7, the switches 808 in Fig. 8, and / or the electrical circuit 1306 in Fig. 13. In some of these examples, the sensor data analyzer 1402 communicates the detected occurrence of a feedback operation to the detachment alert generator 1408 to cause a detachment alert to be generated, since a detachment state precedes a feedback operation. In some examples, data from the sensor 1402 data analyzer cannot independently indicate whether a detachment event occurred. In some of these examples, the detachment alert generator 1408 determines whether a detachment event occurred based on analysis from the sensor data analyzer 1402 and data from the door position monitor 1404. For example, the sensor data analyzer 1402 in the illustrated example communicates data indicating whether one or more of the scanners 606 detected tags 604 to the detachment alert generator 1408, which determines whether a detachment state occurred based on data indicating whether tags 604 and a door curtain position 104 were detected from the door position monitor 1404. In some examples, the sensor data analyzer 1402 additionally communicates location data and / or other decoded data based on the tags 604.Similarly, the sensor data analyzer 1402 in the illustrated example communicates data indicating the status of one or more of the switches 808 in Fig. 8. In some examples, the sensor data analyzer 1402 communicates the states of the switches 808 to the detachment alert generator 1408, to be used in conjunction with the data from the door position monitor 1404 to determine whether the door curtain 104 was in a detachment state. Additionally, the sensor data analyzer 1402 in the illustrated example analyzes data from sensors 1004, 1104, and 1204 in Fig. 10-12 to determine whether the door curtain 104 was present within the guide 110 at the sensor locations. This determination is communicated to the detachment alert generator 1408, which determines whether or not the door curtain 104 was in a detachment state based on this determination and the data from the door position monitor 1404. The sensor 1402 data analyzer in the illustrated example analyzes data from sensor 904 in Fig. 9 to determine if a feedback operation occurred. In some examples, the sensor 1402 data analyzer compares data from sensor 904 with data from a similar sensor (for example, the additional sensor 906) placed in another location. ML / t / ZUZZ / UÓ4OO4 part of gate 102. For example, if another sensor of the same type (e.g., a second accelerometer, if sensor 904 is an accelerometer) placed on another component of gate 102 has similar data (e.g., similar acceleration data, similar forces, similar motion, etc.), then a feedback operation is unlikely to have occurred. Conversely, the sensor 1402 data analyzer can determine that a feedback operation occurred when the data from sensor 904 has unique characteristics compared to another sensor mounted on gate 102. In some instances, the sensor 1402 data analyzer is capable of recognizing the characteristics of a feedback operation in the data from sensor 904.In some of these examples, machine learning is used to train the 1402 sensor data analyzer to recognize the characteristics of a feedback operation. The door position monitor 1404 of the illustrated example in fig. 14 determines a position of the door curtain 104. For example, the door position monitor 1404 in the illustrated example can determine a vertical position of the door curtain 104 (for example, a position of the lower edge 105 of the door curtain 104) between the fully open and fully closed positions based on the position and / or output of a motor or other element that operates the door curtain 104. In some examples, the controller 114 determines a position of the door curtain 104 based on data from another component of the controller 114 that issues control commands to adjust a position of the door curtain 104. The door position monitor 1404 communicates position data for the door curtain 104 to the maintenance alert generator 1406, the detachment alert generator 1408, and / or the detachment alert analyzer 1410.The maintenance alert generator 1406 in the illustrated example in Fig. 14 generates maintenance alerts corresponding to potential maintenance problems identified based on data from the sensor data analyzer 1402. The maintenance alert generator 1406 in the illustrated example issues a maintenance alert if the scanner data 606 indicates that a small number (for example, a threshold quantity to indicate a possible detachment state) of the tags 604 were not detected when they were expected to be detected (for example, when the door position monitor 1404 indicates that the door curtain 104 was covering the scanner's vertical position). Similarly, the maintenance alert generator 1406 in the illustrated example can issue a maintenance alert if one or more of the sensors 1004 in Fig.10A does not detect alignment features 118 when they were expected to be detected, assuming that it has been determined that the. MA / t / ZUZZ / UÓ^OÍW door curtain 104 was not in the detachment state. Likewise, the maintenance alert generator 1406 can issue a maintenance alert if one or more of the sensors 1104 in Fig. 11A fail to detect the metallic features 1106 when they were expected to be detected. In some examples, the maintenance alert generator 1406 communicates with the detachment alert generator 1408 to ensure that maintenance alerts are not generated when the door curtain 104 has moved to the detachment state.In some examples, if the detachment alert generator 1408 repeatedly detects that the door curtain 104 is in a detachment state (for example, by detecting that the door curtain 104 is in a detachment state more than a threshold number of times in a period of time), the maintenance alert generator 1406 may issue a maintenance alert to correct an unrestorable detachment state, where the feedback roller assemblies 120 may not be able to restore the door curtain 104 to the operational state. The detachment alert generator 1408 in the illustrated example in Fig. 14 generates detachment alerts in response to determining, based on data from the sensor data analyzer 1402 and the door position monitor 1404, that the door curtain 104 is currently, or was previously, in a detached state. For example, if the door position monitor 1404 indicates that the door curtain 104 was in the position of a sensor, switch, and / or scanner when the data from the sensor, switch, and / or scanner indicated that the door curtain 104 was not present (for example, as determined by the sensor data analyzer 1402), the detachment alert generator 1408 in the illustrated example generates a detachment alert. In some examples, the detachment alert generator 1408 communicates the detachment alert to an operator via a display on or around the controller 114.In some examples, the detachment alert generator 1408 communicates the detachment alert to the detachment alert analyzer 1410 for further analysis to determine the characteristics of the detachment event, possible corrective actions that can be taken to reduce the likelihood of similar detachment events, and / or to generate reports related to detachment events. In some examples, in response to the door position monitor 1404 indicating that the door curtain 104 was not in a position indicated by the sensor, switch, and / or scanner that would indicate the door curtain 104 was not present (for example, the door curtain 104 was higher than the switch, sensor, and / or scanner), the detachment alert generator 1408 determines that there is no indication. MA / t / ZUZZ / UÓ4OO4 that door curtain 104 is in a detachment state, and it is not necessary to generate a detachment alert. The detachment alert analyzer 1410 in the illustrated example of Fig. 14 generates reports associated with detachment alerts generated by the detachment alert generator 1408 and / or triggers adjustments to aspects of door 102 based on the detachment alerts. In the illustrated example, the detachment alert analyzer 1410 includes a report generator of example 1412, a door drive adjuster of example 1414, and a door movement adjuster of example 1416. The sample report generator 1412 in the example illustrated in Fig. 14 generates reports based on detachment alert data from the detachment alert generator 1408 and / or maintenance alert data from the maintenance alert generator 1406. In some examples, report generator 1412 additionally or alternatively generates reports based on data from the sensor data analyzer 1402 and / or the door position monitor 1404. For example, report generator 1412 can analyze detachment alerts, maintenance alerts, sensor data, and / or door position data and determine patterns associated with detachment events and / or maintenance issues. In some of these examples, report generator 1412 generates reports that describe these patterns.In such examples, the 1412 report generator determines corrective actions that can be taken to address the possible causes of detachment and / or maintenance alerts and includes those corrective actions in a report. The 1412 report generator in the illustrated example can communicate reports on detachment events and / or maintenance alerts to a display on controller 114 and / or a display otherwise accessible to an operator. In some examples, the 1412 report generator communicates reports to a central computer system (for example, a computer system that receives data from multiple doors, a computer system that is remote from the door, etc.). The door actuator adjuster 1414 in the illustrated example of Fig. 14 sends door actuator control signals to adjust parameters associated with the door actuator sensors and / or a door actuator component of the controller 114 to address a potential cause of door detachment events. In some examples, door 102 includes one or more sensors that detect people and / or vehicles approaching door 112. In some examples, the one or more sensors communicate with the controller 114 to cause the door curtain 104 to open. MA / t / ZUZZ / UÓ4OO4 is raised to allow the person and / or vehicle to pass through door 112. In some examples, the door drive adjuster 1414 sends door drive control signals to adjust a position (e.g., a rotation angle) of a sensor that will cause the door curtain 104 to rise to allow the person and / or vehicle to move through the entrance 112. In some examples, the door drive adjuster 1414 adjusts a parameter in the controller 114 to adjust a door drive timing. For example, if detachment occurs frequently because the person and / or vehicle passing through the door strikes the door curtain 104 as the curtain moves upward, the door drive adjuster 1414 can reduce the delay between the sensor detecting the person and / or vehicle and the door curtain 104 being actuated.Conversely, if door curtain 104 is struck by a person and / or vehicle while moving down to the closed position, it is possible that door curtain 104 is opening too early and then closing before the person and / or vehicle can fully exit door 112. The door drive adjuster 1414 can make any further adjustments to the sensors that result in the activation of door curtain 104, and / or to how controller 114 responds to data from these sensors, to address a potential cause of detachment events. In some examples, the door drive adjuster 1414 implements adjustments to door drive-related parameters based on patterns analyzed by report generator 1412 and / or recommendations generated by report generator 1412. The example door motion adjuster 1416 sends door adjustment control signals to adjust parameters associated with the opening and closing of door curtain 104. For example, door motion adjuster 1416 can slow down or speed up the rate at which door curtain 104 opens to address a potential cause of detachment events. In some examples, door motion adjuster 1416 adjusts the time that door curtain 104 remains open.For example, if report generator 1412 analyzes detachment alert data from detachment alert generator 1408 and determines that the door is frequently transitioning to the detachment state when two consecutive people and / or vehicles pass through door 112, door movement adjuster 1416 can issue door adjustment control signals to command door curtain 104 to remain open for a longer time so that two or more people and / or vehicles can pass through before door curtain 104 begins to close. In some examples, door movement adjuster 1416 implements adjustments to the... ML / t / ZUZZ / U 44004 parameters related to door movement based on patterns analyzed by report generator 1412 and / or recommendations generated by report generator 1412. In some instances, the door movement adjuster 1416 causes the door curtain 104 to move to a fully open position when a detachment is detected, even if the door curtain 104 is set to open only to a partially open state. For example, because the feedback roller assemblies 120 are located near the top edge of the door curtain 104, the door movement adjuster 1416 may cause the door curtain 104 to retract fully when a detachment is detected, even if the door curtain 104 is set to open only to a partially open position. In some instances, when the door curtain 104 retracts fully, the entire side edges of the door curtain 104 pass through the feedback roller assemblies 120, thus resetting the door curtain 104 to its operating state. While an example of how to implement controller 114 of Figs. 1, 6, 10A, and 11A is illustrated in Fig. 14, one or more of the elements, processes, and / or devices illustrated in Fig. 14 may be combined, divided, rearranged, omitted, eliminated, and / or implemented in any other way. Furthermore, the sensor data analyzer of example 1402, the door position monitor of example 1404, the maintenance alert generator of example 1406, the detachment alert generator of example 1408, the detachment alert analyzer of example 1410, the report generator of example 1412, the door drive adjuster of example 1414, the door movement adjuster of example 1416, and / or, more generally, the controller of example 114 of Fig. 14 can be implemented using hardware, software, firmware and / or any combination of hardware, software and / or firmware.Thus, for example, any of the sensor data analyzer of example 1402, the door position monitor of example 1404, the maintenance alert generator of example 1406, the detachment alert generator of example 1408, the detachment alert analyzer of example 1410, the report generator of example 1412, the door drive adjuster of example 1414, the door movement adjuster of example 1416 and / or, more generally, the controller of example 114 could be implemented by means of one or more analog or digital circuits, logic circuits, programmable processor(s), programmable controller(s), graphics processing unit(s) (GPU(s)), digital signal processor(s) (DSP(s)), application-specific integrated circuit(s) (ASIC(s)), programmable logic device(s) (PLD(s)) and / or field programmable logic device(s). ML / t / ZUZZ / UÓ-TOO^ (FPLD(s)). When reading any of the apparatus or system claims of this patent to cover a purely software and / or firmware implementation, at least one of the sensor data analyzer of example 1402, the door position monitor of example 1404, the maintenance alert generator of example 1406, the detachment alert generator of example 1408, the detachment alert analyzer of example 1410, the report generator of example 1412, the door drive adjuster of example 1414 and / or the door movement adjuster of example 1416 are expressly defined herein to include a non-transient computer-readable storage device or storage disk, such as a memory, a versatile disc (DVD), a compact disc (CD), a Blu-ray disc, etc., including the software and / or firmware. In addition, example controller 114 of figs.Items 1, 6, 10A, and 11A may include one or more elements, processes, and / or devices in addition to those illustrated in Fig. 14, and / or may include more than one of any or all of the illustrated elements, processes, and devices. As used herein, the phrase "in communication," including variations thereof, encompasses direct communication and / or indirect communication through one or more intermediary components, and does not require direct physical communication (e.g., by cable) and / or constant communication, but rather additionally includes selective communication at periodic intervals, scheduled intervals, aperiodic intervals, and / or one-time events. Representative flowcharts of example hardware logic, machine-readable instructions, hardware-implemented state machines, and / or any combination thereof for implementing the 114 controller of Fig. 14 are shown in Figs. 15-21. The machine-readable instructions may be one or more executable programs or part(s) of an executable program to be executed by a computer processor such as the 2212 processor shown on the example 2200 processor platform discussed below in relation to Fig. 22.The program can be incorporated into software stored on a non-transient, computer-readable storage medium, such as a CD-ROM, floppy disk, hard disk, DVD, Blu-ray disc, or memory associated with the 2212 processor. However, the entire program and / or parts of it could alternatively be executed by a device other than the 2212 processor and / or incorporated into dedicated firmware or hardware. Furthermore, although the example programs are described with reference to the flowchart illustrated in Figures 15-21, many other methods can be used to implement Example Controller 114. For example, the execution order of the blocks can be changed, and / or some of the described blocks can be modified, deleted, or combined.Additional or computer-readable data stored on a non-transient computer and / or machine-readable medium, such as a hard disk drive, flash memory, read-only memory, compact disc, digital versatile disc, cache, random access memory, and / or any other storage device or storage disk on which information is stored for any duration (e.g., for extended periods, permanently, for brief instances, for temporary buffering, and / or for caching information). As used herein, the term non-transient computer-readable medium is expressly defined to include any type of computer-readable storage device and / or storage disk and to exclude propagation signals and transmission media. The terms "that includes" and "comprising" (and all their forms and tenses) are used here as open-ended terms. Therefore, whenever a claim employs any form of "includes" or "comprises" (e.g., "comprises," "includes," "comprising," "having," etc.) as a preamble to or within the mention of a claim of any kind, it should be understood that additional elements, terms, etc., may be present without falling outside the scope of the relevant claim or citation. As used here, when the phrase "at least" is used as a transitional term, e.g., in the preamble to a claim, it is open-ended in the same way that the terms "comprising" and "including" are open-ended.The term "and / or," when used, for example, in a form such as A, B, and / or C, refers to any combination or subset of A, B, and C, such as (1) A alone, (2) B alone, (3) C alone, (4) A with B, (5) A with C, (6) B with C, and (7) A with both B and C. As used here in the context of describing structures, components, elements, objects, and / or things, the phrase "at least one of A and B" is intended to refer to implementations that include any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. Similarly, as used here in the context of describing structures, components, elements, objects, and / or things, the phrase "at least one of A or B" is intended to refer to implementations that include any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B.As used here in the context of describing the performance or execution of processes, instructions, actions, activities, and / or steps, the phrase “at least one of A and B” refers to implementations that include any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. Similarly, as used here in the context of describing the performance or execution of processes, instructions, actions, activities, and / or steps, the phrase at least one of A or B is intended to refer to implementations that include any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. The example machine-readable instructions 1500 that can be executed by controller 114 to detect a door curtain detachment event using the first door curtain detachment detection system of Fig. 6 are illustrated in Fig. 15. With reference to the preceding figures and the associated description, the example machine-readable instructions 1500 in Fig. 15 begin with example controller 114 accessing the signal(s) from one or more sensors (block 1502). In some examples, sensor data analyzer 1402 accesses the signal(s) from one or more of the scanners 606. In block 1506, the example controller 114 determines whether door curtain 104 is moving. In some examples, the door position monitor 1404 determines whether door curtain 104 is moving based on a motor and / or other element that actuates door curtain 104. In some examples, the door position monitor 1404 determines whether door curtain 104 is moving based on another component of controller 114 that commands the movement of door curtain 104. If the door curtain is moving, processing is transferred to block 1506. Conversely, if door curtain 104 is not moving, processing returns to block 1502. In block 1506, the example controller 114 determines whether the number of observed tags detected corresponds to an expected number of tags for the elapsed movement duration. In some examples, the detachment alert generator 1408, based on data from the sensor data analyzer 1402 and the door position monitor 1404, determines whether the number of observed tags 604 detected in scanner data 606 corresponds to an expected number of tags 604 for the elapsed movement duration. In some examples, the detachment alert generator 1408 determines the expected number of tags 604 for the elapsed duration based on a door curtain speed 104 from the door position monitor 1404, and based on a known spacing between tags 604.In response to the number of observed labels detected that correspond to the expected number of labels for the elapsed movement duration, processing is transferred to block 1516. Conversely, in response to the number of observed labels detected that do not correspond to the expected number of labels for the elapsed movement duration, processing transfers to block 1508. ML / t / ZUZZ / UÓ^OÍW In block 1508, example controller 114 determines whether the duration of unrecognized tag movement exceeds a detachment duration threshold. In some examples, detachment alert generator 1408 determines whether the duration of unrecognized tag movement 604 exceeds a detachment duration threshold. In some examples, detachment alert generator 1408 alternatively determines whether a number of tag 604 failures exceeds a detachment tag quantity threshold. The detachment tag quantity threshold quantifies a minimum number of 604 tags expected to be removed from guide 110 during the smallest possible detachment event (for example, a detachment event with the minimum number of door curtain 104 in a detachment state).In response to the duration of movement without tag recognition that exceeds a detachment duration threshold, processing is transferred to block 1510. Conversely, in response to the duration of movement without tag recognition that does not exceed a detachment duration threshold, processing is transferred to block 1512. In block 1510, the example controller 114 generates a detachment detection alert. In some examples, the detachment alert generator 1408 generates a detachment detection alert. For example, the detachment alert generator 1408 can transmit a signal visually (for example, via a display on controller 114), audibly, or otherwise to inform an operator that a detachment event has occurred. Processing is then transferred to block 1516. In block 1512, the example controller 114 determines whether a detachment event has been dismissed. In some examples, the detachment alert generator 1408 determines whether a detachment alert has been dismissed by determining whether a time equal to or greater than the detachment duration threshold has elapsed since the detection of the possible missing tag(s) (for example, after the time when the number of observed tags detected did not correspond to the expected number of tags for the elapsed duration, as per block 1506). In some examples, the possible missing tag(s) may be due to a detachment event, and the detachment alert generator 1408 may require more time to determine whether a detachment event occurred or whether possible missing tag(s) were detected.In order to rule out a detachment event, process transfers to block 1514. Conversely, in response to not ruling out a detachment event, processing is transferred to block 1516. In block 1514, the example controller 114 generates an alert corresponding to the potentially missing tag(s), including their locations. In some examples, the maintenance alert generator 1406 generates data and / or alerts corresponding to missing or malfunctioning tags 604. In some examples, the data and / or alerts include the location(s) (for example, vertical distances on door curtain 104) of the potentially faulty or malfunctioning tags. In block 1516, example controller 114 determines whether to continue monitoring. If monitoring continues, processing is transferred to block 1502. Conversely, if monitoring does not continue, processing ends. The example machine-readable instructions 1600 that can be executed by controller 114 to detect a door curtain detachment event using the second door curtain detachment detection system of Figs. 7A and / or 7B are illustrated in Fig. 16. With reference to the preceding figures and the associated description, the example machine-readable instructions 1600 in Fig. 16 begin with the example controller 114 accessing the signal(s) from one or more switches associated with the feedback roller(s) (block 1602). In some examples, the sensor data analyzer 1402 accesses the signal(s) from one or more of the switches 704 in Figs. 7A and / or 7B associated with the feedback roller(s) 122. In block 1604, the example controller 114 determines whether there has been a change in the signal(s) of one or more switches. In some examples, the sensor data analyzer 1402 determines whether there has been a change in the signal(s) of one or more of the switches 704. In response to the detection of a change in one or more signals of one or more of the switches 704, processing is transferred to block 1606. Conversely, in response to not detecting a change in one or more signals of one or more of the switches 704, processing is transferred to block 1608. In block 1606, the example controller 114 generates a detachment detection alert. In some examples, the detachment alert generator 1408 generates a detachment detection alert. The detachment detection alert can be an audible alert, a visual alert (for example, communicated via a display on controller 114, communicated via a display on a central computing device, etc.), or any other form of alert. In block 1608, example controller 114 determines whether to continue monitoring. If monitoring continues, processing is transferred to block 1602. Conversely, if monitoring does not continue, processing ends. The example machine-readable instructions 1700 that can be executed by controller 114 to detect a door curtain detachment event using the third door curtain detachment detection system of Fig. 8 are illustrated in Fig. 17. With reference to the preceding figures and the associated description, the example machine-readable instructions 1700 in Fig. 17 begin with the example controller 114 accessing signals from one or more of the switches (block 1702). In some examples, the sensor data analyzer 1402 accesses the signal(s) from one or more of the switches 808 in Fig. 8. In block 1704, the example controller 114 determines whether there has been a change in one or more of the signals. In some examples, the sensor data analyzer 1402 determines whether there has been a change in one or more of the switch signals 808. In response to a change in one or more of the signals, processing is transferred to block 1706. Conversely, in response to no change in one or more of the signals, processing is transferred to block 1712. In block 1706, the example controller 114 determines whether the signal change(s) correspond to an expected change in the door curtain position. In some examples, the detachment alert generator 1408 determines whether the signal change(s) correspond to an expected change in a door curtain position 104 based on data from the door position monitor 1404. For example, if the sensor data analyzer 1402 determines, based on a signal from a particular switch 808, that the door curtain 104 is no longer detected next to one of the switches 808, the detachment alert generator 1408 can determine whether this is expected based on whether the door curtain 104 has moved to a position above the particular switch 808 (and is therefore not expected to be adjacent to the particular switch 808).In response to the signal change(s) corresponding to an expected change in the curtain door position, processing is transferred to block 1712. Conversely, in response to the signal change(s) that do not correspond to an expected change in the curtain door position, processing is transferred to block 1708. In block 1708, example controller 114 generates a detachment detection alert. In some examples, detachment alert generator 1408 generates a detachment detection alert. In block 1710, example controller 114 determines a portion of door curtain 104 that has separated from guide 110 based on the signal change(s). In some examples, detachment alert generator 1408 determines a portion of the door that has separated from guide 110 based on a known position of door curtain 104 and knowledge of the location of the switch(s) that detected the signal change. For example, detachment alert generator 1408 might determine that the entire portion of door curtain 104 below the switch that detected the signal change (later determined to be due to door curtain 104 being in a detached state) is in the detached state. In block 1712, example controller 114 determines whether to continue monitoring. If monitoring continues, processing is transferred to block 1702. Conversely, if monitoring does not continue, processing ends. The example machine-readable instructions 1800 that can be executed by controller 114 to detect a door curtain detachment event using the fourth door curtain detachment detection system of Fig. 9 are illustrated in Fig. 18. With reference to the preceding figures and the associated description, the example machine-readable instructions 1800 in Fig. 18 begin with example controller 114 accessing sensor data (block 1802). In some examples, sensor data analyzer 1402 accesses sensor data from sensor 904 of Fig. 9. In block 1804, the example controller 114 analyzes the sensor data to determine the force and / or motion characteristics of the feedback block. In some examples, the sensor data analyzer 1402 analyzes the sensor data 904 to determine the force and / or motion characteristics of feedback block 124a. In some examples, the sensor data analyzer 1402 determines the velocity and / or acceleration characteristics of feedback block 124a. In block 1806, the example controller 114 analyzes sensor data from one or more additional sensors 906 to determine the control force and / or motion characteristics. In some examples, the sensor data analyzer 1402 analyzes sensor data from one or more additional sensors 906 mounted elsewhere on the door 100 (for example, not mounted on the feedback assembly 120) to provide setpoint / control data that can be used by the detachment alert generator 1408 to determine whether a detachment event has occurred. In some examples where the additional sensors 906 are not used, the MA / t / ZUZZ / UÓ^OÍW block 1806. In block 1808, the example controller 114 determines whether a door curtain detachment event has been detected. In some examples, the detachment alert generator 1408 determines whether the door curtain 104 has entered the detachment state based on the characteristics of the data analyzed by the sensor data analyzer 1402. Specifically, if the sensor data analyzer 1402 and / or the detachment alert generator 1408 determines that the sensor data characteristics of sensor 904 correspond to a feedback operation, then it can be determined that a door curtain detachment event has occurred (since a detachment must have preceded a feedback operation).In some examples, the sensor data analyzer 1402 and / or the detachment alert generator 1408 may compare the data from sensor 904 with the data from the additional sensor(s) 906 located elsewhere on door 102, as analyzed in block 1806, to determine whether a force and / or motion characteristic of sensor 904 is unique to feedback block 124a and therefore may potentially indicate a feedback operation. In some examples, the sensor data analyzer 1402 and / or the detachment alert generator 1408 compares characteristics of the sensor data with known characteristics (e.g., observed in training data, programmed into the sensor data analyzer 1402, etc.) of feedback operations. Upon determining that a door curtain detachment event has been detected, processing is transferred to block 1810.Conversely, in response to determining that a door curtain detachment event has not been detected, processing is transferred to block 1812. In block 1810, example controller 114 generates a detachment detection alert. In some examples, detachment alert generator 1408 generates a detachment detection alert. In block 1812, example controller 114 determines whether to continue monitoring. If monitoring continues, processing is transferred to block 1802. Conversely, if monitoring does not continue, processing ends. The example machine-readable instructions 1900 that can be executed by controller 114 to detect a door curtain detachment event using any of the door curtain detachment detection systems of Fig. 10A-C, 11A-C and / or 12 are illustrated in Fig. 19. With reference to the preceding figures and the associated description, the example machine-readable instructions 1900 MA / t / ZUZZ / UÓ^OÍW of Fig. 19 begin with the example controller 114 accessing the signal(s) from one or more sensors (block 1902). In some examples, the sensor data analyzer 1402 accesses the signal(s) from one or more of the sensors 1004 of Fig. 10A, the sensors 1104 of Figs. 11A-C, and / or the photoelectric sensor 1204 of Fig. 12. In block 1904, the example controller 114 determines whether there has been a change in one or more of the signals. In some examples, the sensor data analyzer 1402 determines whether there has been a change in one or more of the sensor signals 1004. In response to a change in one or more of the signals, processing is transferred to block 1906. Conversely, in response to the absence of a change in one or more of the signals, processing is transferred to block 1912. In block 1906, example controller 114 determines whether the signal change(s) correspond to an expected change in the curtain door position. In some examples, detachment alert generator 1408 determines whether the signal change(s) correspond to an expected change in a door curtain position 104 based on data from door position monitor 1404.As a first example, the data analyzer of sensor 1402 can determine, based on a signal from one of the sensors 1004, 1104, 1204, that the door curtain 104 is no longer detected by sensors 1004 (e.g., based on not detecting one of the alignment features 118 for a period of time while the door is moving next to sensor 1004), sensors 1104 (e.g., based on not detecting one of the metallic features 1106 for a period of time while the door is moving next to sensor 1104), and / or sensor 1204 (e.g., based on the light beam 1210 passing through the path of the door curtain 104 between the first and second parts 1206, 1208 of sensor 1204).If, based on the curtain door position data and knowledge of the curtain door speed 104, sensor 1004, 1104, 1204 would have been expected to see a signal change, and this did not occur, the detachment alert generator 1408 can determine that the signal change data does not correspond to an expected change in the curtain door position. As a second example, if door curtain 104 is known to be above sensors 1004, 1104, and 1204 continues to move upward, no change in the position of door curtain 104 would be expected (and therefore no anticipated signal change, at least until the direction of movement of door curtain 104 changes to move toward and then past sensors 1004, 1104, and 1204). In a third example, specific to Fig. 10A for explanatory purposes, a lower edge of door curtain 104 is four feet below sensor 1004. ML / t / ZUZZ / UÓ^OÍW knows that the speed of door curtain 104 is 30.48 cm (one foot) / second, the door is known to be moving upward, and the alignment features are evenly distributed every 15.24 cm (six inches) vertically. If, in this third example, no signal changes associated with the detection of alignment features are detected for two seconds (for example, during that time, four alignment features should have been detected), the detachment alert generator 1408 can determine that a detachment event has occurred. In response to the signal change(s) corresponding to an expected change in the position of the curtain door, processing is transferred to block 1912. Conversely, in response to the signal change(s) that do not correspond to an expected change in the position of the curtain door, processing is transferred to block 1908. In block 1908, example controller 114 generates a detachment detection alert. In some examples, detachment alert generator 1408 generates a detachment detection alert. In block 1910, the example controller 114 determines a portion of door curtain 104 that has separated from the guide 110 based on the signal change(s). In some examples, the detachment alert generator 1408 determines a portion of door curtain 104 that has separated from the guide 110 based on changes in the signal(s) from the sensor data analyzer 1402 and the door position from the door position monitor 1404. For example, based on the door position and the location of the sensor where the door curtain 104 was detected as being in a detachment state, it can be determined that the portion of door curtain 104 between the sensor and a lower edge of the door curtain 104 is in a detachment state. In block 1912, example controller 114 determines whether to continue monitoring. If monitoring continues, processing is transferred to block 1902. Conversely, if monitoring does not continue, processing ends. The example machine-readable instructions 2000 that can be executed by the controller 114 to detect a door curtain detachment event using the eighth door curtain detachment detection system of Fig. 13 are illustrated in Fig. 20. With reference to the preceding figures and the associated description, the example machine-readable instructions 2000 in Fig. 20 begin with the example controller 114 determining whether a signal has been received through a detachment detection circuit (block 2002). In some examples, the sensor data analyzer 1402 determines whether a signal has been received through the electrical circuit 1306, indicating that a feedback operation has occurred in which a conductor of alignment feature 118 closed the electrical circuit 1306 by engaging a pair of feedback rollers 122.In response to a signal being received through the detachment detection circuit, processing is transferred to block 2004. Conversely, in response to no signal being received through the detachment detection circuit, processing is transferred to block 2006. In block 2004, example controller 114 generates a rockfall detection alert. In some examples, rockfall alert generator 1408 generates a rockfall detection alert. In block 2006, example controller 114 determines whether to continue monitoring. In response to continued monitoring, processing is transferred to block 2002. Conversely, in response to interrupted monitoring, processing ends. The example machine-readable instructions 2100 that can be executed by controller 114 to analyze detachment event data and trigger adjustments based on the analysis of the detachment event data are illustrated in Fig. 21. With reference to the preceding figures and the associated description, the example machine-readable instructions 2100 in Fig. 21 begin with example controller 114 accessing door curtain detachment event alerts and associated data (block 2102). In some examples, detachment alert analyzer 1410 accesses door curtain detachment event alerts from detachment alert generator 1408 and associated data from sensor data analyzer 1402. In block 2104, the sample controller 114 analyzes detachment event data to determine the extent of expected product damage. In some examples, report generator 1412 analyzes detachment event data to determine the extent of expected product damage. In some examples, report generator 1412 analyzes detachment occurrence patterns to attempt to identify a cause of door curtain 104 transitioning to the detachment state. In some examples, report generator 1412 estimates the amount of damage to door components 102, based on the number of detachment events and / or data associated with the detachment events (for example, the detachment location along door curtain 104).For example, report generator 1412 can generate a report indicating that 50% of door curtain detachment events originated in the upper half of door curtain 104, indicating that these were not “near misses” where the vehicle and / or person only made contact with the lower edge of door curtain 104 as it moved to the open position. In some instances, report generator 1412 is integrated with maintenance alert generator 1406 and / or works in conjunction with maintenance alert generator 1406 to generate reports that quantify and / or describe the damage sustained by door curtain components 104.For example, report generator 1412 and / or maintenance alert generator 1406 can report on an amount of wear to door curtain 104, an amount of wear on alignment features 118 due to excessive feedback operation, etc. In block 2106, the example controller 114 determines whether there is data indicating a missing alignment feature and / or missing tag(s) on the door curtain. In some examples, the maintenance alert generator 1406 determines whether data received by the sensor data analyzer 1402 indicates that one of the alignment features 118 is missing, or that one of the tags 604 may be missing or malfunctioning.For example, the maintenance alert generator 1406 may determine that there is data indicating missing and / or failing tags 604 if (1) the door position monitor 1404 determines that the door curtain 104 passed in front of one of the scanners 606 for a distance and / or duration that should have enabled the scanner 606 to detect one or more of the tags 604, and (2) the detachment alert generator 1408 and / or the sensor data analyzer 1402 determined that the door curtain 104 did not enter the detachment state. In response to data indicating missing alignment feature(s) and / or tag(s) on the door curtain, processing is transferred to block 2108. Conversely, in response to no data indicating missing alignment feature(s) and / or tag(s) on the door curtain, processing is transferred to block 2110. In block 2108, example controller 114 generates a maintenance alert. In some examples, maintenance alert generator 1406 generates a maintenance alert. For example, maintenance alert generator 1406 can communicate an alert to a maintenance facility, a maintenance operator, and / or another entity, to allow for the subsequent correction of the potential maintenance problem (for example, a missing alignment feature, a malfunctioning label, etc.). In block 2110, example controller 114 analyzes events from MA / t / ZUZZ / UÓ4OO4 Detachment for patterns. In some examples, report generator 1412 analyzes detachment events for patterns. For example, report generator 1412 may attempt to identify patterns related to people and / or vehicles initiating the transition of door curtain 104 to the detached state, patterns related to people and / or vehicles approaching the door, patterns related to the time of day when detachment events occur, etc. In block 2112, example controller 114 adjusts one or more of the drive sensor settings or positions, door speed, door opening time, and / or other door behaviors to address a potential cause of door detachment. In some examples, door drive adjuster 1414 adjusts a parameter associated with a sensor that causes door curtain 104 to move to the open position. For example, door drive adjuster 1414 might adjust a delay between the time motion is detected and the time door curtain 104 begins to open. In some examples, door drive adjuster 1414 adjusts the position of one or more sensors that cause door curtain 104 to move to the open position. In some examples, door motion adjuster 1416 adjusts the speed of door curtain 104.In some examples, the door movement adjuster 1416 adjusts the amount of time that the door curtain 104 remains open. The door drive adjuster 1414 and / or the door movement adjuster 1416 can send control signals to make adjustments based on recommendations generated by the report generator 1412 and / or based on alerts generated by the maintenance alert generator 1406 or the detachment alert generator 1408. Figure 22 is a block diagram of an example 2200 processor platform structured to execute the instructions in Figures 15-21 to implement the 114 controller of Figure 14. The 2000 processor platform can be, for example, a server, a personal computer, a workstation, a self-learning machine (e.g., a neural network), a mobile device (e.g., a cell phone, a smartphone, a tablet such as an iPad™), a personal digital assistant (PDA), an Internet device, or any other type of computing device. The 2200 processor platform in the illustrated example includes a 2212 processor. The 2212 processor in the illustrated example is hardware. For example, the 2212 processor can be implemented by one or more integrated circuits, logic circuits, microprocessors, GPUs, DSPs, or controllers from any family or manufacturer. The hardware processor can be a semiconductor-based device (for example, MA / t / ZUZZ / UÓ4OO4 silicon-based). In this example, the processor implements the example 1402 sensor data analyzer, the example 1404 door position monitor, the example 1406 maintenance alert generator, the example 1408 detachment alert generator, the example 1410 detachment alert analyzer, the example 1412 report generator, the example 1414 door drive adjuster, and the example 1416 door movement adjuster. The processor 2212 in the illustrated example includes a local memory 2213 (for example, a cache). The processor 2212 in the illustrated example communicates with a main memory that includes volatile memory 2214 and non-volatile memory 2216 via a bus 2218. The volatile memory 2214 can be implemented using synchronous dynamic random-access memory (SDRAM), dynamic random-access memory (DRAM), RAMBUS® dynamic random-access memory (RDRAM®), and / or any other type of random-access memory device. The non-volatile memory 2216 can be implemented using flash memory and / or any other desired type of memory device. Access to the main memory 2214 and 2216 is controlled by a memory controller. The 2200 processor platform in the illustrated example also includes a 2220 interface circuit. The 2220 interface circuit can be implemented using any type of interface standard, such as an Ethernet interface, a Universal Serial Bus (USB), a Bluetooth® interface, a Near Field Communication (NFC) interface, and / or a PCI Express interface. In the illustrated example, one or more input devices 2222 are connected to the interface circuit 2220. The input devices 2222 allow a user to enter data and / or commands into the processor 2212. Input devices can be implemented by, for example, an audio sensor, a microphone, a camera (still or video), a keyboard, a button, a mouse, a touchscreen, a touchpad, a trackball, a dot, and / or a voice recognition system. One or more output devices 2224 are also connected to the interface circuit 2220 of the illustrated example. The output devices 2224 can be implemented, for example, by display devices (e.g., a light-emitting diode (LED), an organic light-emitting diode (OLED), a liquid crystal display (LCD), a cathode ray tube (CRT), an in-place switching display (IPS), a touchscreen, etc.), a touch output device, a printer, and / or a speaker. The interface circuit 2220 of the illustrated example, therefore, typically includes a graphics controller card, a graphics controller chip, and / or a graphics controller processor. The 2220 interface circuit in the illustrated example also includes a communication device such as a transmitter, receiver, transceiver, modem, residential gateway, wireless access point, and / or network interface to facilitate data exchange with external machines (e.g., computing devices of any type) over a 2226 network. Communication can be via, for example, an Ethernet connection, a digital subscriber line (DSL) connection, a telephone line connection, a coaxial cable system, a satellite system, a site line wireless system, a cellular telephone system, etc. The illustrated example 2200 processor platform also includes one or more mass storage devices for storing software and / or data. Examples of such mass storage devices include floppy disk drives, hard disk drives, compact disc drives, Blu-ray disc drives, redundant array of independent disks (RAID) systems, and digital versatile disc (DVD) drives. The machine-executable instructions 2232 of Figures 15 to 21 can be stored on the mass storage device 2228, in volatile memory 2214, in non-volatile memory 2216 and / or on a non-transient, computer-readable removable storage medium, such as a CD or DVD. From the above, it will be appreciated that examples of methods, devices, and manufacturing components have been disclosed that allow for the detection of curtain detachment events in doors and subsequent analysis and adjustments to address the root cause of these events. The examples disclosed here reduce damage to detachable doors by accurately identifying when the curtain detachment event occurs and by providing additional data such as locations (e.g., vertical locations along a curtain door) where the detachment event took place. By analyzing curtain detachment events, the example techniques described here identify patterns in the detachment events and lead to adjustments of components associated with detachable doors to address the underlying causes.In addition, the example techniques described here include detecting potential maintenance problems with a detachable door and accurately generating maintenance alerts. Example 1 includes an apparatus comprising a sensor for detecting a side edge of a curtain door within a door guide, and a controller for MA / t / ZUZZ / UÓ-TOO^ identify when the door curtain transitions from an operating state to a detachment state based on a signal from the sensor, the operating state corresponding to when the side edge of the door curtain is enclosed by the guide as the door curtain moves between the open and closed positions, the detachment state corresponding to when a portion of the side edge of the door curtain below an upper end of the guide separates from the guide. Example 2 includes an apparatus from Example 1, and further includes a feedback assembly for feeding back the side edge of the door curtain to the guide in response to the door curtain transitioning to the detachment state, the sensor being below the feedback assembly. Example 3 includes the apparatus in accordance with either Examples 1 or 2, wherein the sensor is a scanner disposed in the guide, the scanner for detecting a tag attached to the side edge of the door curtain, the tag for moving within the guide when the door curtain moves in the operating state. Example 4 includes an apparatus from Example 3, wherein the controller must determine that the door curtain is in a detached state based on (1) whether the scanner detects the label and (2) a vertical position of the door curtain. Example 5 includes an apparatus of Example 4, wherein the controller determines that the door curtain is in a detached state when (1) the vertical position of the door curtain corresponds to a lower edge of the door curtain that is below a scanner height and (2) the scanner does not detect at least one of a plurality of tags, the plurality of tags including the tag. Example 6 includes an apparatus from Example 5, in which the controller must determine a distance between the label and the bottom edge of the door curtain based on the signal data associated with the label. Example 7, which includes the apparatus of any of Examples 3 to 6, wherein the label is a REID label. Example 8 includes the apparatus in accordance with any of Examples 3-7, wherein the scanner is positioned vertically in the lower half of the guide. Example 9 includes the apparatus in accordance with either Examples 1 or 2, wherein the sensor is a switch, the switch communicating a first signal when the door curtain is present next to the switch and a second signal when the door curtain is not present next to the switch. Example 10 includes an apparatus from Example 9, in which the sensor is at least partially embedded in a sealing portion of the guide. Example 11 includes an apparatus of example 10, wherein the switch is spring-loaded, the switch retracts when the door curtain is present next to the switch. Example 12 includes the apparatus in accordance with either Examples 10 or 11, wherein the sealing portion is to reduce airflow through a door associated with the door. Example 13 includes the apparatus in accordance with either Examples 1 or 2, wherein the sensor is to be mounted on the guide, the sensor facing the side edge of the door curtain. Example 14 includes an apparatus from Example 13, in which the sensor is mounted in a hole in the guide. Example 15 includes the apparatus of 13 or 14, wherein the door curtain includes a plurality of alignment features, the sensor for detecting the alignment features. Example 16 includes the apparatus in accordance with any of Examples 13-15, wherein the sensor is either a capacitive proximity sensor or an ultrasonic proximity sensor. Example 17 includes an apparatus of example 15, wherein one of the plurality of alignment features includes a metallic part. Example 18 includes an apparatus from Example 17, in which the sensor is an inductive proximity sensor. Example 19 includes an apparatus of Example 15, wherein one of the plurality of alignment features includes a magnet, and the sensor is a Hall sensor. Example 20 includes the apparatus in accordance with any of Examples 15-19, in which the controller must identify a missing alignment feature based on sensor data. Example 21 includes the apparatus in accordance with any of Examples 13-15, wherein the sensor is a magnetometer, the magnetometer for detecting the presence of a vehicle passing through the gate. Example 22 includes an apparatus from Example 13, wherein an outer edge of the side edge of the door curtain includes a metallic feature, the sensor for detecting the metallic feature. Example 23 includes an apparatus of Example 22, wherein the sensor is pushed toward the outermost edge by a polarizing element to place a sensor assembly in contact with the outermost edge, the sensor assembly including the sensor. Example 24 includes an apparatus from Example 23, wherein the sensor assembly includes a roller for interacting with the outermost edge. Example 25 includes the apparatus in accordance with either Examples 1 or 2, wherein the sensor is a photoelectric sensor, the photoelectric sensor for detecting a beam of light transmitted through a door curtain path when the door curtain is in the detachment state, the door curtain for blocking the beam of light when the door curtain is in the operating state. Example 26 includes an apparatus of Example 25, in which the photoelectric sensor is a retroreflective optical sensor. Example 27 includes the apparatus in accordance with any of Examples 1-26, wherein the sensor is one of a plurality of sensors distributed along the guide. Example 28 includes the apparatus in accordance with any of Examples 1-27, wherein the controller includes a door motion adjuster to cause the door curtain to move to a fully open position in response to the transition of the door curtain from the operating state to the detachment state. Example 29 includes an apparatus of Example 28, wherein the door movement adjuster must cause the door curtain to move to the fully open position in response to (1) the transition of the door curtain from the operating state to the detachment state and (2) the door curtain being set for partially open operation. Example 30 includes the apparatus in accordance with either Examples 1-24, or 27-29, wherein the door curtain includes a reflective surface and the sensor is a photoelectric sensor, the photoelectric sensor detecting a beam of light reflected off the reflective surface when the door curtain is in the operating state, the sensor does not detect the beam of light when the door curtain is in the detachment state. Example 31 includes an apparatus comprising a feedback roller assembly including an electronic component for detecting a feedback operation, the feedback operation for moving a curtain door from a detached state to an operating state, at least a portion of a side edge of the door curtain being displaced out of a guide for the door curtain when the door curtain is in the detached state, the side edge of the door being MA / EZZUZZ / UO4OO4 will guide within the guide when the door curtain is in the operational state, and a controller to identify when the door curtain transitions from an operational state to a detachment state based on a signal from the electronic component. Example 32 includes an apparatus from Example 31, wherein the electronic component includes a switch, the switch being activated based on the lateral movement of a feedback roller associated with the feedback roller assembly. Example 33 includes an apparatus from Example 32, and also includes a spring to deflect the feedback roller towards the switch. Example 34 includes an apparatus from Example 31, wherein the electronic component is a sensor mounted on a feedback roller assembly to detect movement indicative of feedback operation. Example 35 includes an apparatus of example 34, in which the sensor is an accelerometer. Example 36 includes an apparatus of Example 35, wherein the sensor is a first sensor, the apparatus further includes a second sensor mounted in a separate location from the feedback roller assembly to provide reference point sensor data, the controller to identify when the door curtain has passed from the operating state to the detachment state based on a comparison of the reference point sensor data with the data provided by the first sensor. Example 37 includes an apparatus of example 34, in which the sensor is embedded within the feedback roller assembly. Example 38 includes the apparatus in accordance with any of Examples 31-37, wherein the feedback roller assembly includes a pair of feedback rollers, a first feedback roller of the pair to be placed on a first side of the door curtain, a second feedback roller of the pair to be placed on a second side of the door curtain, the door curtain including a conductive feature, the conductive feature for contacting the pair of feedback rollers during feedback operation, wherein the electronic component is an electronic circuit for connecting an input power supply and the controller through the pair of feedback rollers and the electronic circuit during feedback operation. Example 39 includes an apparatus from Example 38, in which the controller identifies when the door curtain has moved from the operating state to the detachment state in response to a signal received from the electronic circuit. Example 40 includes the apparatus in accordance with any of the ML / t / ZUZZ / UÓ-TOO^ examples 38 or 39, in which the pair of feedback rollers must cause the driving feature to move to align with the guide during the feedback operation. Example 41 includes an apparatus comprising a detachment alert generator for generating an output that includes an indication of whether a curtain door moved between a detachment state and an operating state, a side edge of the curtain door that is aligned with a guide when the curtain door is in the operating state, at least a portion of the side edge that is out of alignment with the guide when the curtain door is in the detachment state, and a detachment alert analyzer for determining a portion of the curtain door that separated from the guide and caused the curtain door to move into the detachment state from the operating state. Example 42 includes an apparatus of example 41, wherein the detachment alert analyzer is to cause an adjustment to a feature of a door system associated with the door curtain. Example 43 includes the apparatus of Example 42, wherein the feature corresponds to at least one of (1) a positioning of a door actuator sensor, (2) a door actuation time, or (3) an amount of time that the door curtain remains open after moving to an open position. Example 44 includes the apparatus in accordance with either Examples 42 or 43, which further includes a sensor data analyzer to determine at least one presence of the door curtain in the guide or an occurrence of a feedback operation, and a door position monitor to determine a vertical position of the door curtain. The detachment alert generator must generate the output based on (1) the at least one presence of the door curtain in the guide or the occurrence of the feedback operation and (2) the vertical position of the door curtain. Example 45 includes the apparatus of example 44, wherein the sensor data analyzer must determine whether one of a plurality of door curtain alignment features is missing based on sensor data, the alignment features being attached to the side edge of the door curtain to retain the side edge of the door curtain within the guide. Example 46 includes the apparatus of example 45, and also includes a maintenance alert generator to generate a maintenance alert in response to the sensor data analyzer that determines one of the plurality of characteristics of MA / t / ZUZZ / UÓ4OO4 alignment. Example 47 includes the apparatus in accordance with any of Examples 41-46, wherein the detachment alert analyzer is to generate a report that includes at least one of (1) a prevalence of the door curtain transitioning to the detachment state from the operating state, (2) expected damage to a door system component based on the door transitioning to the detachment state from the operating state, or (3) a recommended adjustment to reduce the likelihood of the door curtain transitioning to the detachment state from the operating state. Example 48 includes the apparatus in accordance with any of Examples 41-47, and further includes a door movement adjuster to cause the door curtain to move to a fully open position in response to (1) the transition of the door curtain from the operating state to the detachment state and (2) the door curtain being set for partially open operation. Example 49 includes a method comprising generating an output that includes an indication of whether a curtain door moved between a detached state and an operating state, a side edge of the curtain door is aligned with a guide when the curtain door is in the operating state, at least a portion of the side edge is out of alignment with the guide when the curtain door is in the detached state, and determining a portion of the curtain door that separated from the guide causing the curtain door to transition to the detached state from the operating state. Example 50 includes the method of Example 49, which also includes causing an adjustment to a feature of a door system associated with the door curtain. Example 51 includes the method of Example 50, wherein the feature corresponds to at least one of (1) a positioning of a door actuator sensor, (2) a door actuation time, or (3) an amount of time that the door curtain remains open after moving to an open position. Example 52 includes the method of either Examples 50 or 51, which further includes determining at least one of the presence of the door curtain in the guide or an occurrence of a feedback operation, and determining a vertical position of the door curtain, generating the output based on (1) at least one of the presence of the door curtain in the guide or the occurrence of the feedback operation and (2) the vertical position of the door curtain. Example 53 includes the method of any of Examples 50 to 52, ML / t / ZUZZ / UÓ^OÍW in addition to generating a report that includes at least one of (1) a prevalence of the door curtain transitioning to the detachment state from the operating state, (2) expected damage to a door system component based on the door transitioning to the detachment state from the operating state, or (3) a recommended adjustment to reduce the probability of the door curtain transitioning to the detachment state from the operating state. Example 54 includes the method of any of Examples 50-53, and further includes determining whether one of a plurality of alignment features or a door curtain label is missing based on sensor data, the plurality of alignment features attached to the side edge of the door curtain to retain the side edge of the door curtain within the guide. Example 55 includes the method of Example 54, which also includes generating a maintenance alert in response to the determination that one of the plurality of alignment features is missing. Example 56 includes a non-transient computer-readable medium comprising machine-readable instructions that, when executed, cause a processor to generate, in executing an instruction with the processor, an output that includes an indication of whether a curtain door moved between a detached state and an operating state, a side edge of the curtain door that is aligned with a guide when the curtain door is in the operating state, at least a portion of the side edge that is out of alignment with the guide when the curtain door is in the detached state, and determining a portion of the curtain door that separated from the guide causing the curtain door to move to the detached state from the operating state. Example 57 includes the computer-readable medium of Example 56, wherein the instructions, when executed, further cause the processor to cause an adjustment to a feature of a door system associated with the door curtain. Example 58 includes the computer-readable medium of Example 57, wherein the feature corresponds to at least one of (1) a positioning of a door actuator sensor, (2) a door actuation time, or (3) an amount of time that the door curtain remains open after moving to an open position. Example 59 includes the computer-readable means of either Examples 57 or 58, wherein the computer-readable instructions, when executed, cause the processor to determine, when executing an instruction with the processor, at least one of a presence of the door curtain in the guide or an occurrence of a feedback operation, and to determine, when executing an instruction with the processor, a vertical position of the door curtain, whereby to generate the output based on (1) the at least one of the presence of the door curtain in the guide or the occurrence of the feedback operation and (2) the vertical position of the door curtain. Example 60 includes the computer-readable means of any of Examples 57-59, wherein the computer-readable instructions, when executed, cause the processor to generate a report that includes at least one of (1) a prevalence of the door curtain transitioning to the detach state from the operating state, (2) expected damage to a door system component based on the door transitioning to the detach state from the operating state, or (3) a recommended adjustment to reduce the probability of the door curtain transitioning to the detach state from the operating state. Example 61 includes the computer-readable means of any of Examples 57-60, wherein the computer-readable instructions, when executed, cause the processor to determine whether one of a plurality of door curtain alignment features is missing based on sensor data, the plurality of alignment features being positioned on the side edge of the door curtain to retain the side edge of the door curtain within the guide. Example 62 includes the computer-readable medium of Example 61, wherein the computer-readable instructions, when executed, cause the processor to generate a maintenance alert in response to the determination that one of the plurality of alignment features is missing. Example 63 includes an apparatus comprising a detachment alert generator for determining a curtain door moved from an operating state to a detachment state, a side edge of the door curtain that is aligned with a guide when the door curtain is in the operating state, at least a portion of the side edge that is out of alignment with the guide when the door curtain is in the detachment state, and a door movement adjuster for causing the door curtain to move to a fully open position to restore the door curtain to the operating state in response to the transition of the door curtain from the operating state to the detachment state. Example 64 includes an apparatus of Example 63, wherein the door movement adjuster is to cause the door curtain to move to the fully open position in response to (1) the transition of the door curtain from the operating state to the detachment state and (2) the door curtain being configured to act between a closed position and a partially open position when the door curtain is in the operating state. Although certain examples of manufacturing methods, apparatus, and articles have been described herein, the scope of this patent is not limited to them. Rather, this patent covers all manufacturing methods, apparatus, and articles that fall within the scope of the claims herein.

Claims

1. An apparatus characterized in that it comprises: a sensor for detecting a side edge of a curtain door within a door guide; and a controller for identifying when the door curtain passes from an operating state to a detachment state based on a signal from the sensor, the operating state corresponding to when the side edge of the door curtain is enclosed by the guide as the door curtain moves between the open and closed positions, the detachment state corresponding to when a portion of the side edge of the door curtain below an upper end of the guide separates from the guide.

2. The apparatus according to claim 1, characterized in that it further includes a feedback assembly for feeding back the side edge of the door curtain in the guide in response to the transition of the door curtain to the detachment state, the sensor being located below the feedback assembly.

3. The apparatus according to claim 2, characterized in that the sensor is a scanner disposed in the guide, the scanner for detecting a label fixed to the lateral edge of the door curtain, the label for moving within the guide when the door curtain moves in the operating state.

4. The apparatus according to claim 3, characterized in that the controller must determine that the door curtain is in the detachment state based on (1) whether the scanner detects the label and (2) a vertical position of the door curtain.

5. The apparatus according to claim 4, characterized in that the controller must determine that the door curtain is in the detached state when (1) the vertical position of the door curtain corresponds to a lower edge of the door curtain that is below the height of the scanner and (2) the scanner does not detect at least one of a plurality of labels, the plurality of labels including the label.

6. The apparatus according to claim 5, characterized in that the controller determines a distance between the label and the lower edge of the door curtain based on serial data associated with the label.

7. The apparatus according to claim 3, characterized in that the label is a REID label.

8. The apparatus according to claim 3, characterized in that the scanner is positioned vertically in a lower half of the guide.

9. The apparatus according to claim 1, characterized in that the sensor is a switch, the switch communicating a first signal when the door curtain is present next to the switch and a second signal when the door curtain is not present next to the switch.

10. The apparatus according to claim 9, characterized in that the sensor is at least partially embedded in a sealing portion of the guide.

11. The apparatus according to claim 10, characterized in that the switch is spring-operated, the switch retracts when the door curtain is present next to the switch.

12. The apparatus according to claim 10, characterized in that the sealing portion must reduce the airflow through a door associated with the door.

13. The apparatus according to claim 1, characterized in that the sensor is to be mounted on the guide, the sensor being oriented towards the lateral edge of the door curtain.

14. The apparatus according to claim 13, characterized in that the sensor is mounted in a hole in the guide.

15. The apparatus according to claim 14, characterized in that the door curtain includes a plurality of alignment features, the sensor for detecting the alignment features.

16. The apparatus according to claim 15, characterized in that the sensor is a capacitive proximity sensor or an ultrasonic proximity sensor.

17. The apparatus according to claim 15, characterized in that one of the plurality of alignment features includes a metallic part.

18. The apparatus according to claim 17, characterized in that the sensor is an inductive proximity sensor.

19. The apparatus according to claim 15, characterized in that one of the plurality of alignment features includes a magnet, and the sensor is a Hall sensor.

20. The apparatus according to claim 15, characterized in that the controller must identify a missing alignment feature based on the sensor data.

21. The apparatus according to claim 13, characterized in that the sensor is a magnetometer, the magnetometer being for detecting the presence of a vehicle passing through the door. MA / t / ZUZZ / UÓ^OÍW 22. The apparatus according to claim 13, characterized in that an outer edge of the side edge of the door curtain includes a metallic feature, the sensor for detecting the metallic feature.

23. The apparatus according to claim 22, characterized in that the sensor is driven towards the outermost edge by a polarizing element to place a sensor assembly in contact with the outermost edge, the sensor assembly including the sensor.

24. The apparatus according to claim 23, characterized in that the sensor assembly includes a roller for interfacing with the outermost edge.

25. The apparatus according to claim 1, characterized in that the sensor is a photoelectric sensor, the photoelectric sensor must detect a beam of light transmitted through a door curtain path when the door curtain is in the detachment state, the door curtain must block the beam of light when the door curtain is in the operating state.

26. The apparatus according to claim 25, characterized in that the photoelectric sensor is a retroreflective optical sensor.

27. The apparatus according to claim 1, characterized in that the sensor is one of a plurality of sensors distributed along the guide.

28. The apparatus according to claim 1, characterized in that the controller includes a door movement adjuster to cause the door curtain to move to a fully open position in response to the transition of the door curtain from the operating state to the detachment state.

29. The apparatus according to claim 28, characterized in that the door movement adjuster causes the door curtain to move to the fully open position in response to (1) the transition of the door curtain from the operating state to the detachment state and (2) the door curtain being configured for partially open operation.

30. The apparatus according to claim 1, characterized in that the door curtain includes a reflective surface and the sensor is a photoelectric sensor, the photoelectric sensor must detect a beam of light reflected on the reflective surface when the curtain door is in the operating state, the sensor must not detect the beam of light when the door curtain is in the detachment state.

31. An apparatus characterized in that it comprises: a feedback roller assembly including an electronic component for detecting a feedback operation; the feedback operation for the transition of a curtain door from a detached state to an operating state, at least a portion of a side edge of the door curtain is to be displaced out of a guide for the door curtain when the door curtain is in the detached state, the side edge of the door is to be guided into the guide when the door curtain is in the operating state; and a controller for identifying when the door curtain transitions from an operating state to a detached state based on a signal from the electronic component.

32. The apparatus according to claim 31, characterized in that the electronic component includes a switch, the switch being actuated based on the lateral movement of a feedback roller associated with the feedback roller assembly.

33. The apparatus according to claim 32, characterized in that it further includes a spring for deflecting the feedback roller towards the switch.

34. The apparatus according to claim 31, characterized in that the electronic component is a sensor mounted on a feedback roller assembly for detecting movement indicative of feedback operation.

35. The apparatus according to claim 34, characterized in that the sensor is an accelerometer.

36. The apparatus according to claim 35, characterized in that the sensor is a first sensor, the apparatus further includes a second sensor mounted in a separate location from the feedback roller assembly to provide reference point sensor data, the controller being required to identify when the door curtain has transitioned from the operating state to the detachment state based on a comparison of the reference point sensor data with the data provided by the first sensor.

37. The apparatus according to claim 34, characterized in that the sensor is embedded within the feedback roller assembly.

38. The apparatus according to claim 31, characterized in that the feedback roller assembly includes a pair of feedback rollers, a first feedback roller of the pair being disposed on a first side of the door curtain, a second feedback roller of the pair being disposed on a second side of the door curtain, the door curtain including a conductive feature, the conductive feature being in contact with the pair of feedback rollers during the feedback operation, wherein the electronic component is an electronic circuit for connecting an input power supply and the controller through the pair of feedback rollers and the electronic circuit during the feedback operation.

39. The apparatus according to claim 38, characterized in that the controller must identify when the door curtain has passed from the operating state to the detachment state in response to a signal received from the electronic circuit.

40. The apparatus according to claim 38, characterized in that the pair of feedback rollers are for causing the driving feature to move until it aligns with the guide during the feedback operation.

41. An apparatus characterized in that it comprises: a detachment alert generator for generating an output that includes an indication of whether a curtain door has moved between a detachment state and an operating state, a side edge of the curtain door aligned with a guide when the curtain door is in the operating state, at least a portion of the side edge is misaligned with the guide when the curtain door is in the detachment state; and a detachment alert analyzer for determining a portion of the curtain door that has detached from the guide causing the curtain door to transition to the detachment state from the operating state.

42. The apparatus according to claim 41, characterized in that the detachment alert analyzer must cause an adjustment to a feature of a door system associated with the door curtain.

43. The apparatus according to claim 42, characterized in that the feature corresponds to at least one of (1) a positioning of a door actuation sensor, (2) a door actuation time, or (3) an amount of time that the door curtain remains open after moving to an open position.

44. The apparatus according to claim 42, characterized in that it further includes: a sensor data analyzer for determining at least one presence of the door curtain in the guide or an occurrence of a feedback operation; and a door position monitor for determining a vertical position of the door curtain, the detachment alert generator for generating the output based on (1) the at least one presence of the door curtain in the guide or the occurrence of the feedback operation and (2) the vertical position of the door curtain.

45. The apparatus according to claim 44, characterized in that the sensor data analyzer determines whether one of a plurality of door curtain alignment features is missing based on the sensor data, the alignment features being attached to the side edge of the door curtain to retain the side edge of the door curtain within the guide.

46. ​​The apparatus according to claim 45, characterized in that it further includes a maintenance alert generator for generating a maintenance alert in response to the sensor data analyzer failing to determine one of the plurality of alignment features.

47. The apparatus according to claim 42, characterized in that the detachment alert analyzer generates a report that includes at least one of (1) a prevalence of the door curtain transitioning to the detachment state from the operating state, (2) expected damage to a door system component based on the door transitioning to the detachment state from the operating state, or (3) a recommended adjustment to reduce the probability of the door curtain transitioning to the detachment state from the operating state.

48. The apparatus according to claim 41, characterized in that it further includes a door movement adjuster for causing the door curtain to move to a fully open position in response to (1) the transition of the door curtain from the operating state to the detachment state and (2) the door curtain being configured for partially open operation.

49. A method characterized in that it comprises: generating an output that includes an indication of whether a curtain door has moved between a detached state and an operating state, a side edge of the curtain door that is aligned with a guide when the curtain door is in the operating state, at least a portion of the side edge is misaligned with the guide when the curtain door is in the detached state; and determining a portion of the curtain door that detached from the guide causing the curtain door to move to the detached state from the operating state.

50. The method according to claim 49, characterized in that it further includes causing an adjustment to a feature of a door system associated with the door curtain.

51. The method according to claim 50, characterized in that the feature corresponds to at least one of (1) a positioning of a door actuator sensor, (2) a door actuation time, or (3) an amount of time that the door curtain remains open after moving to an open position.

52. The method according to claim 50, characterized in that: determining at least one of the presence of the door curtain in the guide or an occurrence of a feedback operation; and determining a vertical position of the door curtain, generating the output based on (1) at least one of the presence of the door curtain in the guide or the occurrence of the feedback operation and (2) the vertical position of the door curtain.

53. The method according to claim 50, characterized in that it further includes generating a report that includes at least one of (1) a prevalence of the door curtain transitioning to the detachment state from the operating state, (2) expected damage to a door system component based on the door transitioning to the detachment state from the operating state, or (3) a recommended adjustment to reduce the probability of the door curtain transitioning to the detachment state from the operating state.

54. The method according to claim 50, characterized in that it further includes determining whether one of a plurality of alignment features or a door curtain label is missing based on sensor data, the plurality of alignment features being positioned on the side edge of the door curtain to retain the side edge of the door curtain within the guide.

55. The method according to claim 54, characterized in that it further includes generating a maintenance alert in response to the determination of one of the plurality of alignment characteristics.

56. A non-transient, computer-readable medium characterized in that it comprises machine-readable instructions that, when executed, cause a processor to: generate, when executing an instruction with the processor, an output that includes an indication of whether a curtain door moved between a detached state and an operating state, a side edge of the curtain door that is aligned with a guide when the curtain door is in the operating state, at least a portion of the side edge that is out of alignment with the guide when the curtain door is in the detached state; and determine a portion of the curtain door that separated from the guide causing the curtain door to transition to the detached state from the operating state.

57. The computer-readable medium according to claim 56, characterized in that the instructions, when executed, further cause the processor to cause an adjustment to a feature of a gate system associated with the ML / t / ZUZZ / UÓ-TOO^ gate curtain.

58. The computer-readable medium according to claim 57, characterized in that the feature corresponds to at least one of (1) a positioning of a door actuator sensor, (2) a door actuation time, or (3) an amount of time that the door curtain remains open after moving to an open position.

59. The computer-readable medium according to claim 57, characterized in that the computer-readable instructions, when executed, cause the processor to: determine, when executing an instruction with the processor, at least one of the presence of the door curtain in the guide or an occurrence of a feedback operation; and determine, when executing an instruction with the processor, a vertical position of the door curtain, where to generate the output based on (1) the at least one of the presence of the door curtain in the guide or the occurrence of the feedback operation and (2) the vertical position of the door curtain.

60. The computer-readable medium according to claim 57, characterized in that the computer-readable instructions, when executed, cause the processor to generate a report that includes at least one of (1) a prevalence of the door curtain transitioning to the detach state from the operating state, (2) expected damage to a door system component based on the door transitioning to the detach state from the operating state, or (3) a recommended adjustment to reduce the probability of the door curtain transitioning to the detach state from the operating state.

61. The computer-readable means according to claim 57, characterized in that the computer-readable instructions, when executed, cause the processor to determine whether one of a plurality of door curtain alignment features is missing based on sensor data, the plurality of alignment features being attached to the side edge of the door curtain to retain the side edge of the door curtain within the guide.

62. The computer-readable medium according to claim 61, characterized in that the computer-readable instructions, when executed, cause the processor to generate a maintenance alert in response to the determination that one of the plurality of alignment features is missing.

63. An apparatus characterized in that it comprises: a detachment alert generator for determining a curtain door moved from an operating state to a detachment state, a side edge of the door curtain that is aligned with a guide when the door curtain is in the operating state, at least a portion of the side edge that is out of alignment with the guide when the door curtain is in the detachment state; and a door movement adjuster for causing the door curtain to move to a fully open position to restore the door curtain to the operating state in response to the transition of the door curtain from the operating state to the detachment state.

64. The apparatus according to claim 63, characterized in that the door movement adjuster causes the door curtain to move to the fully open position in response to (1) the transition of the door curtain 10 from the operating state to the detachment state and (2) the door curtain being configured to operate between a closed position and a partially open position when the door curtain is in the operating state.

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