WO2023285803A1

WO2023285803A1 - A damage detection system for elongate structures

Info

Publication number: WO2023285803A1
Application number: PCT/GB2022/051798
Authority: WO
Inventors: David Edgar; Milos BOZIC; Matthew WROE; Mark Bonner
Original assignee: Three Smith Group Limited
Priority date: 2021-07-15
Filing date: 2022-07-12
Publication date: 2023-01-19
Also published as: GB202110191D0; GB2608859A

Abstract

A damage detection system for an elongate structure, comprising: a wire configured to be held under tension and extend internally along a length of the elongate structure; and a controller configured to detect deformation to a sidewall of the elongate structure by sensing an associated deflection of the wire by the elongate structure.

Description

A DAMAGE DETECTION SYSTEM FOR ELONGATE STRUCTURES

The present disclosure relates to a damage detection system for an elongate structure and a method for detecting damage in an elongate structure.

Summary

According to a first aspect of the present disclosure there is provided a damage detection system for a warehouse, comprising; an elongate structure for a warehouse; a wire configured to be held under tension and extend internally along a length of the elongate structure; and a controller configured to detect deformation to a sidewall of the elongate structure by sensing an associated deflection of the wire by the elongate structure.

The wire may be configured to extend internally through a cavity of the elongate structure extending along a length of the elongate structure.

The elongate structure may be a resilient elongate structure. The elongate structure may comprise a polymer safety structure. .

The damage detection system may comprise a deflection detector. The controller may receive an output signal from the deflection detector and/or monitor a state of the deflection detector to sense the deflection of the wire.

The cavity may include one or more restrictions along its length.

An axis of the wire may be configured to be offset from a central axis of the elongate structure when the structure is in an undamaged state.

The wire may comprise one or more protuberances along a length of the wire, the protuberances extending radially from the wire.

The protuberances may be radially non-symmetric. The protuberances may be spherical, ellipsoidal or disc shaped.

A cross-sectional shape of the protuberances may comprise a reduced scale version of a cross-sectional shape of the cavity of the elongate structure.

The protuberances may be magnetised. The damage detection system may further comprises a magnetometer for monitoring movement of the magnetised protuberances.

The controller may be configured to sense the associated deflection of the wire based on a level of strain in the wire.

The damage detection system may further comprise a strain detector for measuring the level of strain in the wire.

The strain detector may comprise a strain gauge coupled to the wire.

The wire may comprise a piezoelectric material and the controller may be configured to measure the level of strain in the wire based on a voltage across the wire.

The piezoelectric material may be polyviny!idene difluoride.

The controller may be configured to determine the deflection of the wire based on the level of strain in the wire and a predetermined relationship between the level of strain and the associated deflection of the wire.

The controller may be configured to determine a reference level of strain in the wire as part of a calibration routine. The controller may be configured to determine a deflection of the wire based on a change in the level of strain in the wire relative to the reference level of strain and a predetermined relationship between the level of strain and the associated deflection of the wire.

The controller may be configured to determine a level of damage to the elongate structure based on the deflection of the wire, the level of strain in the wire and / or a change in the level of strain in the wire exceeding one or more thresholds. The one or more thresholds may include a maximum acceptable deformation threshold corresponding a maximum sidewall deformation beyond which the elongate structure is deemed beyond repair,

The controller may be configured to determine the associated deflection in the wire by monitoring: the integrity of the wire; and / or the integrity of a mechanical coupling coupled to the wire,

The controller may be configured to output a damage signal representative of the deformation of the sidewall and / or the deflection of the wire.

The controller may be configured to output a damage signal representative of the level of damage to the elongate structure.

The damage detection system may further comprise an audible and / or visual indicator, wherein the controller is configured to output the damage signal by activating the audible and / or visual indicator.

The controller may be configured to output the damage signal by transmitting the damage signal to an external device.

The controller is co-located with the wire. The controller may be coupled to the wire via a network. The controller may comprise a plurality of processors distributed between being co-located with the wire or coupled to the wire via the network.

The controller may be further configured to: receive trigger signalling; selectively activate the damage detection system in response to the trigger signalling; and sense any deflection in the wire.

The trigger signalling may comprise a periodic trigger signal for selectively activating the damage detection system according to a monitoring schedule.

The trigger signalling may comprise an on-demand signal from a trigger sensor responsive to: motion of an object within a predetermined radius of the eiongate structure; and / or impact of an object with the eiongate structure.

The eiongate structure may comprise any of: a racking limb, a safety barrier, a safety boliard, a safety rail, a post for a safety rail, a collision sensor, or a component part thereof.

The damage detection system may comprise: a plurality of elongate structures; a plurality of wires, wherein each wire is held under tension and extends internally along a length of a corresponding one of the plurality of elongate structures; a plurality of transceivers each coupled to a corresponding wire; and a server configured to communicate with each of the plurality of transceivers.

According to a second aspect of the present disclosure there is provided a damage detection system for an elongate structure, comprising: a wire configured to be held under tension and extend internally along a length of the elongate structure; and a controller configured to detect deformation to a sidewall of the elongate structure by sensing an associated deflection of the wire by the eiongate structure.

The damage detection system may comprise the elongate structure. The elongate structure may comprise any of: a racking limb, a safety barrier, a safety bollard, a safety rail, a post for a safety rail, a collision sensor, or a component part thereof.

The damage detection system may further comprise: a plurality of wires, wherein each wire is held under tension and extends internally along a length of a corresponding elongate structure; a plurality of transceivers each coupled to a corresponding wire; and a server configured to communicate with each of the plurality of transceivers.

According to a further aspect of the present disclosure there is provided a method of monitoring damage in an eiongate structure, the method comprising: sensing a deflection of a wire held under tension and extending internally along a length of the elongate structure; and detecting deformation to a sidewall of the elongate structure based on the deflection of the wire. The method may be computer implemented.

There may be provided a computer program, which when run on a computer, causes the computer to configure any apparatus, including a circuit, controller, converter, or device disclosed herein or perform any method disclosed herein. The computer program may be a software implementation, and the computer may be considered as any appropriate hardware, including a digital signal processor, a microcontroller, and an implementation in read only memory (ROM), erasable programmable read only memory (EPROM) or electronically erasable programmable read only memory (EEPROM), as non-limiting examples. The software may be an assembly program.

The computer program may be provided on a computer readable medium, which may be a physical computer readable medium such as a disc or a memory device, or may be embodied as a transient signal. Such a transient signal may be a network download, including an internet download. There may be provided one or more non-transitory computer-readable storage media storing computer-executable instructions that, when executed by a computing system, causes the computing system to perform any method disclosed herein.

Brief Description of the Drawings

One or more embodiments will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1A illustrates a perspective view of a damage detection system for an elongate structure in an undamaged state according to an embodiment of the present disclosure;

Figure IB illustrates a cross-sectional view of the damage detection system of Figure 1A following deformation of the elongate structure;

Figure 2A illustrates a perspective view of another damage detection system for an elongate structure in an undamaged state according to an embodiment of the present disclosure;

Figure 2B illustrates a cross-sectional view of the damage detection system of Figure 2A following deformation of the elongate structure;

Figure 2C illustrates a perspective view of a further damage detection system for an elongate structure in an undamaged state according to an embodiment of the present disclosure; Figure 2D illustrates a cross-sectional view of the damage detection system of Figure 2C following deformation of the elongate structure;

Figure 2E illustrates a cross-sectional view of a further damage detection system for an elongate structure undergoing deformation according to an embodiment of the present disclosure;

Figure 3A illustrates a cross-sectional view of a yet further damage detection system for an elongate structure in an undamaged state according to an embodiment of the present disclosure;

Figure 3B illustrates a cross-sectional view of the damage detection system of Figure 3A following deformation of the elongate structure;

Figure 4A illustrates a schematic of a damage detection system for a plurality of elongate structures according to an embodiment of the present disclosure;

Figure 4B illustrates a schematic of another damage detection system for a plurality of elongate structures according to an embodiment of the present disclosure; and

Figure 5 illustrates a flow diagram for a method of monitoring damage in an elongate structure.

Detailed Description

Many structures can pose a safety hazard when damaged, for example bridges, buildings and equipment. One damage pathway is a vehicle collision with the structure. For example, in a factory or warehouse environment, vehicles may be required to move within confined spaces and in close proximity to valuable goods and personnel. In a warehouse, forklift trucks (FLTs) may pass between isles of racking or shelving that contain valuable stock. A FLT may have to perform tight turns and manoeuvres to load and unload stock from the racking. Even a skilled driver may accidently collide with racking causing damage and creating a potential safety hazard from the racking collapsing, particularly if the collision is not detected or goes unreported.

Collision sensors on structures can alleviate this risk by detecting and reporting collisions. However, collision sensors may generate many false alarms from nondamaging collisions resulting from a pedestrian brushing past the structure or other- minor vibration events.

The damage detection system disclosed herein is suitable for use with elongate structures, such as posts, barriers or racking pieces, for which it may be advantageous to monitor the structural integrity of the structure and / or collisions or impacts with the structure.

Figures 1A and IB illustrate a damage detection system 100 for an elongate structure 102 according to an embodiment of the present disclosure. The system 100 comprises a wire 104 held under tension and passing internally along a length of the elongate structure 102. The wire 104 may pass through a cavity of the elongate structure 102 extending along its length. The system 100 further comprises a controller 106 to detect deformation to a sidewall 108 of the elongate structure 102 by sensing an associated deflection of the wire 104 by the elongate structure 102.

Figure 1A illustrates a perspective view of the system 100 coupled to the elongate structure 102 in a normal undamaged state. Figure IB illustrates a cross-sectional view of the system 100 and elongate structure 102 after a deformation event which has resulted in deformation of the elongate structure 102. Specifically, a side wail 108 of the elongate structure has deformed. Deformation of the sidewall 108 has resulted in an associated deflection 109 of the wire 104. The controller 106 senses the deflection 109 of the wire 104 thereby detecting the associated sidewall deformation. As will be described in detail below, the controller can sense the deflection 109 of the wire 104 in a number of ways including detecting a change in a level of strain in the wire 104, a change in electrical properties of the wire 104 and / or a disconnection of the wire 104 from a coupling.

As described further below, the controller 106 may output a damage signal representative of the deflection 109 of the wire 104 and deformation of the sidewall 108. The controller 106 may output the damage signal via an output signal generator (not shown).

The damage detection system 100 can advantageously monitor the condition of elongate structures susceptible to damage and detect damage that may otherwise go unnoticed or undetected. The damage detection system 100 can also advantageously complement a collision sensor system to determine whether a collision event is associated with damage to the monitored structure.

The elongate structure 102 may be any elongate structure vulnerable to damage including a limb or piece of racking or shelving in warehouses, and safety structures including safety barrier systems and component parts thereof (eg. barriers, posts), safety fencing, bollards, machine guarding, machine fencing and similar safety structures known in the art, The limb of racking and the safety structures may be referred to as warehouse structures, The system 100 may also monitor safety structures in an outdoor environment, such as a construction site, a car park or an airport, The safety structures may include polymer safety structures that can provide a resilient safety structure, Alternatively, the safety structures may comprise metallic or metal alloy safety structures. In some examples, the elongate structure 102 may form part of the damage detection system 100,

The elongate structure may be a stationary structure, that is a structure designed to reside in a fixed position in a warehouse during operation.

In some examples, the elongate structure may comprise a polymer safety structure. Polymer safety structures (e.g, polyurethane safety structures) can provide robust protective safety structures for warehouse and factory environments and can include safety barriers, safety bollards, safety rails, posts, bumpers, racking, guards, machine guarding, machine fencing or any other structure for protecting or segregating pedestrians and / or assets from vehicle collisions or for protecting or segregating pedestrians from hazard areas. Polymer safety structures that can provide a resilient safety structure. The system 100 can be particularly effective for resilient safety structures because structural damage or weakening may be internal and/or invisible to the naked eye and can go unreported if there was no witness to the damage causing event.

In this example, the elongate structure 102 is a cylindrical shape. However, the elongate structure 102 may comprise any elongate shape. For example, the elongate structure 102 may have a circular, elliptical, generally curved, square, rectangular, quadrilateral, pentagonal, hexagonal or other polygon shaped cross-section. In some examples, the cross-sectional shape of the elongate structure 102 may vary along its length. The cross-sectional shape of the cavity may comprise a reduced scale version of the cross-sectional shape of the elongate structure 102 or may comprise a different cross-sectional shape.

In some examples the wire 104 may be held under tension by coupling each end of the wire 104 to fixing points. The fixing points may form part of the elongate structure 102 or may form part of one or more adjacent structures, for example one or both fixing points may form part of a posts positioned at an end, and optionally coupled to, an elongate safety barrier. The wire 104 may be coupled to the fixing points via one or more other components, such as a strain gauge or a mechanical coupling. In this example, an axis of the wire 104 is offset from a centra! axis of the elongate structure towards the sidewall 108 in the normal undamaged state, In this way, the wire 108 may be positioned closer to a region of the sidewall 108 that is more vulnerable to impact, increasing the sensitivity of the system 100 because less sidewall deformation is required to cause deflection of the wire 104.

Figures 2A to 2E illustrate further damage detection systems 200 according to an embodiment of the present disclosure. Features of Figures 2A to 2E that are also present in Figure 1 have been given corresponding numbers in the 200 series and will not necessarily be described again here,

In this example, the wire 204 comprises one or more protuberances 210 extending radially from the wire 204 and positioned along a length of the wire 204. The protuberances 210 may be integral to the wire 204 or may comprise one or more attachments to the wire 204. The protuberances 210 may be of any shape, for example spherical, ellipsoidal or disc shaped. In some examples, the protuberances 210 may have a cross-sectional shape corresponding to a reduced scale version of the cross- sectional shape of the cavity of the elongate structure 202, The protuberances 210 can increase the sensitivity of the system 200 without requiring the axis of the wire 204 to be offset from the centra! axis of the elongate structure 200 as in the example of Figure 1. A wire 204 without any protuberances, running along a central axis of the elongate structure 202, requires a sidewall deformation equal to a radius of the elongate structure 202 to result in deflection of the wire (assuming a thin sidewall 208). In contrast, a wire 204 comprising protuberances 210 will require a reduced deformation of the sidewall 208 to result in deflection 209 of the wire 204, The reduction in the required deformation of the sidewall 208 may be equal to a radius of the one or more protuberances 210.

Figure 2B illustrates that, as a result of the protuberances 210, the wire 204 will undergo the same deflection 209 for the same sidewall deformation as the system of Figure 1 but with the axis of the wire 204 running along a central axis of the elongate structure 202 in the undamaged state of Figure 2A. In this way, the system 204 can have increased sensitivity to sidewall impacts from any direction. In some examples, the protuberances 210 may be radially non-symmetric to increase a sensitivity to deformation of the sidewall 208 in a particular radial direction. In some examples, the protuberances 210 may comprise magnetised material and the system 200 may further comprise a magnetometer to detect deflections of the protuberances 210.

Figures 2C and 2D illustrate a further damage detection system with increased sensitivity. In this example, the elongate structure 200 comprises a passageway 212 (or conduit) extending axially along its length. Likewise, the elongate structure may be considered to have a thick sidewall 208 with a thickness equal to up to 50% of the external cross-sectional diameter of the elongate structure 202. The wire 204 may pass through the passageway 212 of the elongate structure 202. The passageway 212 can provide the same increased sensitivity effect as the protuberances 210 of Figures 2A and 2B because a reduced deformation of the sidewall 208 will deflect the wire 204. In some examples, the sidewall 208 may be considered to form the passageway 212.

Figure 2E illustrates a yet further damage detection system with increased sensitivity. In this example, the sidewall 208 may be considered as forming a passageway. A diameter of the passageway 212 (or a thickness of the sidewall 208) varies along the length of the elongate structure 202. The passageway 212 includes one or more restrictions 211, or narrowing sections, in which a diameter of the passageway 212 is reduced. In this way, the sidewall 208 of the elongate structure 202 can be thin like in the examples of Figures 1, 2A and 2B and have one or more restricting apertures 211 to provide the increased sensitivity effect.

In some examples, systems may include a combination of protuberances 210, a passageway 212 and / or one or more restricting apertures 211.

The controller may sense a deflection in the wire based on a change in the level of strain or an increase in tension in the wire. The controller may detect the change in the level of strain in a number of ways.

Figures 3A and 3B illustrate a further damage detection system 300 according to an embodiment of the present disclosure. Features of Figures 3A and 3B that are also present in Figures 1 and 2 have been given corresponding reference numbers in the 300 series and will not necessarily be described again here.

In this example, the wire 304 passes internally through a safety barrier 302 and is held under tension by mounting each end of the wire 304 at a respective fixing point 318 1, 318-2 in adjacent support posts 316-1, 316-2. A deflection detector 314 is coupled to the wire 304 and the controller 306. The deflection detector 314 is configured to change state in response to a deflection 309 of the wire 304 and may be implemented in a number of ways. The deflection detector 314 may provide an output signal to the controller 306 or the controller may monitor the state of the deflection detector 314 enabling the controller 306 to sense the deflection 309 in the wire 304.

In some examples, the deflection detector 314 may detect an increase in a level of strain in the wire. If a sidewall 308 of the elongate structure 302 Is deformed as a result of an impact, the associated deflection of the wire 304 will result in an increased level of strain In the wire 304 as the wire 304 is stretched between the fixing points 318-1, 318-2.

In some strain-based examples, the deflection detector 314 may comprise a strain gauge coupled in series with the wire 304 between the two fixing points 318-1, 318-2. For example, a first end of the strain gauge may be coupled to a first fixing point 318- 1; a second end of the strain gauge may be coupled to a first end of the wire 304; and a second end of the wire 304 may be coupled to a second fixing point 318-2. The controller 306 may measure a level of strain or tension in the wire 304 based on the state of the strain gauge. The strain gauge may comprise a resistive based strain gauge comprising circuitry on a substrate wherein a resistance of the circuitry depends on the level of strain (compressive or tensile force) applied to the substrate. The controller 306 may monitor a resistance signal of the strain gauge to determine a level of strain in the wire 304. As discussed below, the controller 306 may determine a corresponding deflection 309 of the wire 304 and deformation of the sidewall 308 based on the level of strain (or change in level of strain) in the wire 304.

In a further strain-based example, the wire 304 may comprise a piezoelectric material, such as polyvinylidene difluoride (PVDF), and the deflection detector 314 may comprise circuitry configured to monitor an electrical voltage across the wire 304. In such an example, the wire 304 itself may be considered as a strain gauge. The piezoelectrical material of the wire 304 will produce a voltage in response to a change in a level of strain in the wire 304 resulting from the stretching of the wire 304 as it deflects. The circuitry of the deflection detector 314 can provide a voltage signal to the controller 306 and the controller 306 can monitor the voltage across the wire 304 based on the voltage signal to determine a level of strain in the wire 304 and a corresponding deflection 309 of the wire 304 and deformation of the sidewall 308. In some examples, the controller 306 may determine a magnitude of deflection of the wire (and corresponding deformation of the sidewall 308 (or magnitude of damage)) based on a magnitude of the determined level of strain and a predetermined relationship between strain in the wire 304 and deflection 309 of the wire 304. The predetermined relationship may depend on the properties of the wire such as material, length, diameter etc. The controller 306 can output a damage signal based on the magnitude of the determined deflection / damage.

The controller 306 may determine a change in the level of strain by comparing the level of strain in the wire 304 against a reference strain level corresponding to the elongate structure 302 and the wire 304 in the normal undamaged state (Figure 3A). The controller 306 may determine the reference strain level as part of a calibration routine. The calibration routine may be performed by the controller 306 at any time including: a time of manufacture, a time of installation, a time of assembly, a time of re-assembly, a time of service and / or a time of relocation of the elongate structure 302. The controller 306 may determine a magnitude of deflection of the wire (and corresponding deformation of the sidewall 308 (or magnitude of damage)) based on the change in the level of strain and the predetermined relationship between strain in the wire 304 and deflection 309 of the wire 304, The controller 306 may output a damage signal based on the change in the level of strain and associated determined deflection/damage.

The controller 306 may compare the level of strain, the change in level of strain and / or the determined deflection 309 to one or more thresholds to determine a level of deformation or damage of the elongate structure 302. The one or more thresholds may correspond to different levels of deformation / damage of the elongate structure 302, The damage level may be qualitive, for example, "light", "medium", "severe", or quantitative with a numeric value based on the value of the level of strain, change in strain, magnitude of deflection and / or the exceeded threshold. A greater degree of damage may be associated with a higher level of strain or change in level of strain allowing damage to be quantified. The one or more thresholds may include a maximum acceptable deformation threshold corresponding to a product specification identifying a maximum sidewall deformation beyond which the elongate structure is not certified or deemed safe for continued use. The one or more thresholds may include a minimum detection threshold below which any changes in the level of strain may be assumed to be non-damaging noise or vibrations, for example vibrations of the wire 304 resulting from passing vehicles. The controller 306 may output the damage signal based on whether the level of strain, change in level of strain or deflection 309 exceeds any of the one or more thresholds. For example, the controller 306 may output a damage signal indicating that the elongate structure 302 has been damaged and remedial action is required such as safety restrictions, inspection, repair and / or replacement of the structure 302. Alternatively, the controller may output a damage signal indicating the elongate structure 302 is undamaged, or not output any damage signal, if the level of strain, change in level of strain or deflection is less than ail of the one or more thresholds.

In some examples, the deflection detector 314 may comprise a mechanical coupling configured to couple the wire 304 to a fixing point 318-1 or configured to couple a first portion of the wire with a second portion of the wire. The mechanical coupling may comprise a simple male-female connector, a snap-fit connector or similar. The deflection 309 of the wire 304 can cause the mechanical coupling to puli apart and eventually decouple the wire 304 from the fixing point or decouple two portions of the wire 304. The level of deflection 309 of the wire 304 required to decouple the mechanical coupling may correspond to the maximum acceptable deformation of the elongate structure 302. In this way, the mechanical coupling can act like an irreversible fuse indicating that the structure 302 has been deformed to such an extent that intervention is required (inspection, repair, replacement etc). The controller 306 can monitor the integrity of the mechanical coupling to determine a level of deformation to the elongate structure 302. In the same way as described above for the strain-based deflection detectors, the controller may output a damage signal indicating a level of damage of the elongate structure 302 based on the state of the mechanical coupling. For example, if the mechanical coupling is intact, the controller may output a damage signal indicating that the elongate structure is undamaged or may not output any damage signal. If the mechanical coupling has decoupled / pulled apart, the controller 306 may output a damage signal indicating that the elongate structure 302 has been damaged and remedial action is required. The controller may monitor the integrity of the mechanical coupling by passing a current through an electrically conductive mechanical coupling or by other means known in the art.

In yet further fuse type examples, the system 300 may not include a mechanical coupling (or deflection detector 314) and the controller 306 may monitor the integrity of the wire 304. The wire 304 may be configured to fracture in response to a deflection corresponding to the maximum acceptable deformation. In this way, the controller 306 can determine a level of deformation or damage to the elongate structure 302. The controller 306 may monitor the integrity of the wire 304 by passing an electric current through the wire 304 and identifying when that electrical current is no longer able to pass along the length of the wire 304.

In the above examples, the controller 306 senses a deflection 309 in the wire 304 resulting from deformation to the sidewall 308 of the elongate structure 302. The deflection 309 can be sensed either using a strain-based measurement or by monitoring the integrity of a mechanical coupling or the integrity of the wire 304 itself. The controller 306 outputs a damage signal based on the sensed deflection 309. For strain-based examples, the controller 306 may output a damage signal based on a deflection magnitude or a level of strain / change in a level of strain relative to a reference. The damage signal may include a degree of deflection, deformation or damage based on the deflection, level of strain or change in level of strain exceeding one or more thresholds. For fuse / integrity based examples, the controller may output a binary damage signal based on whether the wire or mechanical coupling has fractured / decoupled. In such examples, the binary damage signal may define the elongate structure as damaged or undamaged.

In some examples, the controller 306 may monitor or sense any deflection 309 of the wire 304 on a continuous basis. In other examples, the controller 306 may selectively detect deflection 309 of the wire 304 on an on-demand basis in response to receiving a trigger signal. For example, the damage detection signal may reside in a sleep-mode to minimise energy consumption. In the sleep mode, all functionality of the system 300 may be disabled with the exception of the controller 306 listening for trigger signalling. The trigger signalling may comprise a periodic trigger signal according to a monitoring schedule. For example, the controller 306 may activate the system 300 and sense any deflection in the wire 304 at regular time intervals, for example, hourly, daily, weekly etc.

The system 300 may receive the trigger signalling as an on-demand signal from a trigger sensor. The trigger sensor may be responsive to: motion of an object within a predetermined radius of the elongate structure 302; and / or an impact of an object with the elongate structure 302. The controller 306 may activate the system in response to the trigger signalling and sense any deflection in the wire 304 and associated deformation of the structure and provide a damage signal accordingly. In some examples, the system 300 may further comprise the trigger sensor. The trigger sensor may be a low-power device that can remain active during the sleep mode. In some examples, the trigger sensor may comprise a mechanical sensor, for example a vibration or impact sensor such as an accelerometer, The mechanical sensor may form part of a collision sensor system. In some examples, the damage detection system 300 may form part of the collision sensor system. The mechanical sensor may detect vibration resulting from motion of an object (such as a passing vehicle) or from a collision of an object with the system 300 or the elongate structure 302, The mechanical sensor can detect a vibration / impact and, if a magnitude of the vibration is greater than a potential damage threshold, the controller 306 may receive the trigger signalling from the mechanical sensor and activate the damage detection system 300.

The controller 306 can sense any deflection in the wire 304 to determine if the detected vibration is associated with structural damage to the elongate structure 302. In this way, the system 300 can provide damage detection functionality for complementing a collision sensor. By determining the condition of the elongate structure 302, the system 300 can distinguish vibrations at the elongate structure 302 resulting from potentially damaging collisions from those arising from low-risk vibrations such as a pedestrian brushing past the structure. Therefore, the system 300 can reduce false alarms in a collision sensor system.

In some examples, the trigger sensor may comprise an optical sensor for detecting motion. An optical sensor may comprise a passive infrared (PIR) sensor that can detect motion of an object within a predefined radius of the elongate structure 302. The controller 306 may receive signals from the PIR sensor and activate the damage detection system 300 in response to movement of an object within the predefined radius. In some examples, the controller 306 may receive a motion signal from the optical sensor and activate the damage detection system 300 following detection of a moving object. The controller 106 may continuously, or at regular intervals (for example multiple measurements per second), monitor any deflection in the wire 304 until the motion signal indicates that motion is no longer present. In this way, the damage detection system 300 can monitor the condition of the elongate structure 302 throughout the entire motion event. If the moving object damages the elongate structure, the system 300 can capture a transient damage profile of the collision.

As outlined above, the controller 306 may determine deformation of the structure 302 based on any associated deflection 309 in the wire 304 on a continuous basis or on a semi-continuous basis for a short interval based on trigger signalling. For strain-based detection, in which a degree of deflection or damage can be determined, the controller 306 can sense a sequence of deflection values of the wire 304 that can define a deflection profile, In other words, the controller 306 may determine a transient deflection profile based on a sequence of strain measurements. The controller 306 may determine a transient damage profile of the elongate structure based on the transient deflection profile. The controller 306 may store the transient damage profile or transmit it to the server or remote device for analysis of the collision event. Capturing a transient deflection profile or transient damage profile ensures that the maximum deflection, strain or change in strain can be assessed against the one or more thresholds, even for elastic or partially elastic deformations in which the elongate structure relaxes back to a less deformed state. The safety or integrity of the structure 302 can be assessed against regulatory requirements, safety specifications etc based on the maximum deformation undergone by the structure 302.

In some examples, the system 300 may further comprise an output signal generator and the controller 306 may output the damage signal by way of the output signal generator. The output signal generator may comprise an audible signal generator, such as a siren, or a visible signal generator such as a (flashing) light or a display screen displaying warning messages. In this way, the output signal generator can alert pedestrians and vehicle drivers of any potential hazard arising from damage to the elongate structure 302, For example, a warning display may indicate a temporary vehicle speed limit or a no entry alert until the elongate structure 302 is inspected, repaired and / or replaced. The controller 306 may activate the output signal generator if the damage signal indicates that the elongate structure 302 is damaged.

In some examples, the output signal generator may comprise a transmitter configured to transmit the damage signal and / or raw data from the deflection detector to an external device. For example, the transmitter may transmit the damage signal to a remote server, a remote device and / or a mobile device. In this way, the system 300 can alert a user to damage to the elongate structure and may indicate a potential requirement for inspection and / or repair. The damage signal may comprise a data signal including any of deflection detector signals (level of strain, change in level of strain, raw resistances or voltages, integrity of mechanical coupling etc), a magnitude of deflection 309 of the wire 304, a degree of damage ora binary indication of damage. Data from the damage signal may also be stored locally or at the remote server or device for analysis. In this way, data can be captured for the sensor system 300 for indicating how many collisions / potential damage events the elongate structure 302 is exposed to, for example, on a daily, weekly or monthly basis. In the illustrated example, the output signal generator may reside in a cap of the post 316-1, i.e. the output signal generator may be located external and local to the elongate structure 302. The output signal generator may communicate with the controller 306 by wired or wireless means. In other examples, the output signal generator may comprise an audible or visible signal generator located on a wall close to the sensor system. In yet further examples, the output signal generator may be integrated into or positioned on the elongate structure 302.

In some examples, the controller 306 may be positioned local to the elongate structure 302 / wire 304. For example, the controller may be housed within the elongate structure or housed in an adjacent structure such as the post 316-1 of Figures 3A and 3B. In some examples, the system may Include a housing attachable to the exterior of the elongate structure and the controller may be housed in such a housing. The housing may have one or more input controls. For example, the one or more input controls may include one or more function buttons, a touchscreen, switches etc. The controller 306 may be responsive to activation of the one or more input controls to sense a deflection in the wire 304 or perform a calibration routine and / or reset the system 300, for example, by disabling an output signal generator.

In other examples, the controller 306 may be positioned remote from the housing, for example the controller may be implemented on a server or remote device. In such examples, the system 300 may further include a transceiver for transmitting raw data from the deflection detector 314 to the controiler 306.

In further examples, the controller may be realised by one or more processors local to the elongate structure 302 / wire 304 and one or more processors remote from the elongate structure 302 / wire 304, such as on a remote server or remote device. In other words, any functionality of the controller 306 described herein may be performed locally to and / or remotely from the elongate structure 302 / wire 304. The system 300 and / or controller 306 may include a transceiver for communicating with any remote processing device, such as a remote controller or a server.

Figure 4A illustrates a schematic overview of another damage detection system 400 according to an embodiment of the present disclosure. Features of Figure 4A already described above in relation to Figures 1 to 3 have been given corresponding reference numbers in the 400 series and will not necessarily be described again here. The system 400 includes a plurality of sub-systems each associated with an elongate structure 402a_f 402b, 4Q2n for monitoring in an environment such as a warehouse. Each sub-system comprises a wire 404a, 404b, 404n and a controller 406a, 406b, 406n, Each sub-system also comprises a transceiver (not shown) that can communicate with a server 420. The server 420 may comprise a user interface or may communicate with other devices having a user interface such as a personal mobile device or a computer. In this way, the server 420 may collect data from each of the sub-systems to monitor damage and potentially damaging deformation at each of the associated elongate structures 402a, 402b, 4Q2n. The system 400 may determine one or more elongate structures 402a, 402b, 402n that are particularly vulnerable to collisions as structures that have a frequency of collisions and / or frequency of near misses (deflection/deformation above a detection threshold but below a maximum allowable threshold) greater than a corresponding safety threshold. In this way, a user can analyse the monitoring data and implement changes to the structural layout (such as rearranging the layout, implementing protective measures etc) to improve the safety of the environment. In this way, an improved design of the structural layout can be achieved.

In the example, of Figure 4A each subsystem has a dedicated wire 404a, 404b, 4Q4n and a dedicated local controller 406a, 406b, 406c for implementing the controller functionality as described above in relation to Figures 1 to 3.

In some examples, each subsystem may have a dedicated alert signal generator. In other examples, the subsystems may be communicatively coupled with a common alert signal generator. For example, two or more subsystems may be wirelessly coupled to the same audible or visible alert signal generator and/or to a common gateway that can perform some functionality of the controller 406 and/or pass information to and from the server 420.

Figure 4B illustrates a schematic overview of a further damage detection system 400' according to an embodiment of the present disclosure. Features of Figure 4B already described above in relation to Figures 1 to 4A have been given corresponding reference numbers in the 400' series and will not necessarily be described again here.

In this example, the system 400' again includes a plurality of sub-systems each associated with an elongate structure 402'a, 402'b, 402'n for monitoring in an environment such as a warehouse. However, the controller 406' is located at the server- 420' and provides the functionality described above in relation to Figures 1 to 3 for a plurality of the sub-systems. Each sub-system comprises a wire 4Q4'a, 404'b, 4Q4'n and a transceiver 422'a, 422'b, 422'c, In this example, the sub-systems act as dumb devices in that the transceivers 422'a, 422'b, 422'n transmit signals from the corresponding deflection detectors (not shown) to the controller 406' for processing. The transceivers 422'a, 422'b, 422'n may also receive signals from the controller 406' for activating an alert signal generator. In this way, the functionality of the controller 406' described in relation to Figures 1 to 3 can be implemented at the server 420'.

Figures 4A and 4B respectively describe examples in which the controller functionality is implemented local to the sub-system or on the server. It will be appreciated that In other examples any elements of the functionality of the controller described in relation to Figures 1 to 3 may be performed local to the sub-system or remote from the subsystem on the server.

Figure 5 illustrates a flow diagram for a method of monitoring damage in an elongate structure, according to an embodiment of the present disclosure.

A first step 530 comprises sensing a deflection of a wire held under tension and extending internally along a length of the elongate structure. A second step 532 comprises detecting deformation to a sidewall of the elongate structure based on the deflection of the wire.

Throughout the present specification, the descriptors relating to relative orientation and position, such as "horizontal", "vertical", "top", "bottom" and "side", are used in the sense of the orientation of the damage detection system as presented in the drawings. However, such descriptors are not intended to be in any way limiting to an intended use of the described or claimed invention.

It will also be appreciated that any reference to "close to", "before", "shortly before", "after" "shortly after", "higher than", "exceeds, "les than" or "lower than", etc, can refer to the parameter in question being less than or greater than a threshold value, or between two threshold values, depending upon the context.

Claims

1, A damage detection system for a warehouse, comprising: an elongate structure for a warehouse; a wire configured to be held under tension and extend internaiiy along a length of the elongate structure; and a controller configured to detect deformation to a sidewall of the elongate structure by sensing an associated deflection of the wire by the elongate structure.

2, The damage detection system of claim 1, wherein the wire is configured to extend internaiiy through a cavity of the elongate structure extending along a length of the elongate structure.

3, The damage detection system of claim 1 or claim 2, wherein the elongate structure is a resilient elongate structure.

4, The damage detection system of claim 3, dependent on claim 2, wherein the cavity includes one or more restrictions along its length.

5, The damage detection system of any preceding claim, wherein an axis of the wire is configured to be offset from a central axis of the elongate structure when the structure is in an undamaged state.

6, The damage detection system of any preceding claim, wherein the wire comprises one or more protuberances along a length of the wire, the protuberances extending radially from the wire.

7, The damage detection system of claim 6, wherein the protuberances are radially non-symmetric.

8, The damage detection system of claims 6 or claim 7, wherein the protuberances are magnetised and the damage detection system further comprises a magnetometer for monitoring movement of the protuberances.

9. The damage detection system of any preceding claim, wherein the controller is configured to sense the associated deflection of the wire based on a level of strain in the wire.

10. The damage detection system of claim 9, further comprising a strain detector for measuring the level of strain in the wire.

11. The damage detection system of claim 10, wherein the strain detector comprises a strain gauge coupled to the wire.

12. The damage detection system of any of claims 9 to 11, wherein the wire comprises a piezoelectric material and the controller is configured to measure the level of strain in the wire based on a voltage across the wire.

13. The damage detection system of any of claims 9 to 12, wherein the controller is configured to determine the deflection of the wire based on the level of strain in the wire and a predetermined relationship between the level of strain and the associated deflection of the wire,

14. The damage detection system of any of claims 9 to 13, wherein: the controller is configured to determine a reference level of strain in the wire as part of a calibration routine; and determine a deflection of the wire based on a change in the level of strain in the wire relative to the reference level of strain and a predetermined relationship between the level of strain and the associated deflection of the wire,

15. The damage detection system of any of claims 9 to 14, wherein the controller is configured to determine a level of damage to the elongate structure based on the deflection of the wire, the level of strain in the wire and / or a change in the level of strain in the wire exceeding one or more thresholds.

16. The damage detection system of any of claims 1 to 8, wherein the controller is configured to determine the associated deflection in the wire by monitoring: the integrity of the wire; and / or the integrity of a mechanical coupling coupled to the wire.

17. The damage detection system of any preceding claim, wherein the controller is configured to output a damage signal representative of the deformation of the sidewall and / or the deflection of the wire.

18. The damage detection system of claim 17 further comprising an audible and / or visual indicator, wherein the controller is configured to output the damage signal by activating the audible and / or visual indicator.

19. The damage detection system of claim 17, wherein the controller is configured to output the damage signal by transmitting the damage signal to an external device.

20. The damage detection system of any preceding claim, wherein the controller is further configured to: receive trigger signalling; selectively activate the damage detection system in response to the trigger signalling; and sense any deflection in the wire,

21. The damage detection system of claim 20, wherein the trigger signalling comprises a periodic trigger signal for selectively activating the damage detection system according to a monitoring schedule.

22. The damage detection system of claim 20 or claim 21, wherein the trigger signalling comprises an on-demand signal from a trigger sensor responsive to: motion of an object within a predetermined radius of the elongate structure; and / or impact of an object with the elongate structure.

23. The damage detection system of any preceding claim, wherein the elongate structure comprises any of: a racking limb, a safety barrier, a safety bollard, a safety rail, a post for a safety rail, a collision sensor, or a component part thereof.

24. The damage detection system of any preceding claim, further comprising: a plurality of elongate structures; a plurality of wires, wherein each wire is held under tension and extends internally along a length of a corresponding one of the plurality of elongate structures; a plurality of transceivers each coupled to a corresponding wire; and a server configured to communicate with each of the plurality of transceivers.

25. A method of monitoring damage in an elongate structure for a warehouse, the method comprising: sensing a deflection of a wire held under tension and extending internally along a length of the elongate structure; and detecting deformation to a sidewall of the elongate structure based on the deflection of the wire.