Scaffolding safety sensor system and method

Abstract

In accordance with one or more embodiments herein, a system (100) for monitoring the safety of a scaffold (300) is provided The system (100) comprises: a plurality of inertial sensor units (110), each inertial sensor unit (110) being comprised in a wall mounting arrangement (340) of the scaffold (300); a signal receiving unit (200), arranged to receive signals wirelessly from the plurality of inertial sensor units (110); and at least one processing device (120), arranged to determine whether a specific wall mounting arrangement (340) is loose, based at least on signals received from the inertial sensor unit (110) that is comprised in said specific wall mounting arrangement (340). Also provided is a method 6 for monitoring the safety of a scaffold (300).

Description

[0001] SCAFFOLDING SAFETY SENSOR SYSTEM AND METHOD

[0002] TECHNICAL FIELD

[0003] The present disclosure relates generally to systems and methods for monitoring the safety of a scaffold.

[0004] BACKGROUND

[0005] Scaffolds may be exposed to severe weather conditions in the form of e.g. strong winds, ice, or snow. In order to reduce the risk of a scaffold collapsing, or people or parts falling down, it is important that all parts of the scaffold are tightly secured together, and that the scaffold is secured to a wall. However, scaffold fastenings tend to loosen over time, due to vibrations in the scaffold.

[0006] WO2023280666 describes a monitoring system for a scaffold that uses inertial sensor units that are each attached to the scaffold straight outside a wall mounting arrangement of the scaffold. This enables a determination of which wall mounting arrangement that is loose.

[0007] PROBLEMS WITH THE PRIOR ART

[0008] In the scaffold monitoring system described in WO2023280666, it is necessary to attach each inertial sensor unit straight outside a wall mounting arrangement of the scaffold. However, since the wall mounting arrangements must be attached to the scaffold, typically in positions where different parts of the scaffold are attached to each other, it may be difficult to attach the inertial sensor unit straight outside the wall mounting arrangements.

[0009] There is thus a need for improved monitoring of scaffold safety.

[0010] SUMMARY

[0011] The above described problem is addressed by the claimed system for monitoring the safety of a scaffold. The system may comprise: a plurality of inertial sensor units, each inertial sensor unit being comprised in a wall mounting arrangement of the scaffold; a signal receiving unit, arranged to receive signals wirelessly from the plurality of inertial sensor units; and at least one processing device, arranged to determine whether a specific wall mounting arrangement is loose, based at least on signals received from the inertial sensor unit that is comprised in said specific wall mounting arrangement. i The above described problem is further addressed by the claimed method for monitoring the safety of a scaffold. The method may comprise: arranging inertial sensor units to be comprised in wall mounting arrangements of the scaffold; and determining, based at least on signals received from the inertial sensor unit that is comprised in a specific wall mounting arrangement, whether said wall mounting arrangement is loose.

[0012] This enables a determination of exactly which wall mounting arrangement that is loose, without having to try to attach inertial sensor units to the scaffold straight outside the wall mounting arrangements.

[0013] In embodiments, the inertial sensor units are integrated into bars, such as wall tie bars, of the wall mounting arrangements.

[0014] In embodiments, the system is arranged to be self-calibrating, using machine learning based on historical data received from the plurality of inertial sensor units. In this way, the system may automatically determine when there are deviations from the normal operation.

[0015] In embodiments, at least one processing device is located in the signal receiving unit. The may however also be local signal processing in the inertial sensor unit.

[0016] In embodiments, the inertial sensor units comprise accelerometers. The processing of accelerometer signals is a simple yet reliable way of determining whether a wall mounting arrangement is loose.

[0017] In embodiments, the inertial sensor units comprise alerting means, such as e.g. LED:s. In this way, the inertial sensor unit that is comprised in a wall mounting arrangement that is loose may flash its LED to indicate the location of the loose wall mounting arrangement. If there is local signal processing in the inertial sensor unit, the processing device in the inertial sensor unit may determine that the associated wall mounting arrangement is loose, and start flashing its LED. However, if there is two-way communication, the signal receiving unit may also instruct the relevant inertial sensor unit to flash its LED.

[0018] In embodiments, the signal receiving unit comprises alerting means, such as e.g. LED:s and / or audio emitters. Even though such alerting means will not show which wall mounting arrangement that is loose, this may be a more reliable way of indicating to users of the scaffold that there is a problem.

[0019] In embodiments, the signal receiving unit is arranged to communicate with at least one user device. This enables the sending of alerts to one or more persons responsible for the scaffold.

[0020] In embodiments, the system also comprises at least one wind speed sensor. In this way, the determination of whether a specific wall mounting arrangement is loose may be based also on the signals received from said at least one wind speed sensor. This ensures that the signal analysis takes the wind excitation of the scaffold into account.

[0021] The scope of the invention is defined by the claims, which are incorporated into this section by reference. A more complete understanding of embodiments of the invention will be afforded to those skilled in the art, as well as a realization of additional advantages thereof, by a consideration of the following detailed description of one or more embodiments. Reference will be made to the appended sheets of drawings that will first be described briefly.

[0022] BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Fig. 1 schematically illustrates a system for monitoring the safety of a scaffold, in accordance with one or more embodiments described herein.

[0024] Fig. 2 schematically illustrates a scaffold, in accordance with one or more embodiments described herein.

[0025] Fig. 3 schematically illustrates a part of a scaffold, in accordance with one or more embodiments described herein.

[0026] Fig. 4 illustrates a wall mounting arrangement, in accordance with one or more embodiments described herein.

[0027] Figs. 5a-b illustrate an inertial sensor unit, in accordance with one or more embodiments described herein.

[0028] Fig. 6 schematically illustrates a method for monitoring the safety of a scaffold, in accordance with one or more embodiments described herein.

[0029] Embodiments of the present disclosure and their advantages are best understood by referring to the detailed description that follows. It should be appreciated that like reference numerals are used to identify like elements illustrated in one or more of the figures.

[0030] DETAILED DESCRIPTION

[0031] The prior art scaffold monitoring system described in WO2023280666 is only able to determine which wall mounting arrangement that is loose by attaching inertial sensor units straight outside the wall mounting arrangements of the scaffold. However, since the wall mounting arrangements must attached to the scaffold, typically in positions where different parts of the scaffold are attached to each other, it may be difficult to attach them straight outside the wall mounting arrangement. According to the claimed invention, the inertial sensor units are instead comprised in the wall mounting arrangements, e.g. by being integrated into bars of the wall mounting arrangements. Embodiments of the disclosed solution are presented in more detail in connection with the figures.

[0032] Fig. 1 schematically illustrates a system 100 for monitoring the safety of a scaffold. The system 100 comprises a plurality of inertial sensor units 110, which may e.g. comprise accelerometers 130. The system may also comprise one or more further sensors, such as e.g. a wind speed sensor 140. The system 100 also comprises a signal receiving unit 200, which is arranged to receive signals wirelessly from the plurality of inertial sensor units 110 (and the optional further sensors 140). The wireless communication between the inertial sensor units 110 and the signal receiving unit 200 may be any suitable type of wireless communication, such as e.g. Bluetooth, Wi-Fi, or LoRaWAN. If a wireless communication type that has a long range is used, it may be possible to use only one signal receiving unit 200 for a whole scaffold, even if the scaffold is large, and builds around the corners of a house. However, there may also be more than one signal receiving unit 200 in the system 100, if this is necessary. It may also be possible to use one or more relay units to relay the signal to the signal receiving unit 200.

[0033] In order to determine whether the scaffold is safe, a processing device 120 analyses the signals received from the inertial sensor units 110 (and the optional further sensors 140). The processing device 120 may be arranged in the signal receiving unit 200, but it may also be arranged in a remote server, preferably accessible through the internet (e.g. a cloud server). There may also be processing devices 120 in the inertial sensor units 110. The system may thus comprise more than one processing device 120, where one is arranged in the signal receiving unit 200 and one or more others may be arranged in a remote server, and / or in the inertial sensor units 110. If there are processing devices 120 in the inertial sensor units 110, initial processing make take place there, in order to determine whether any sensor data needs to be transferred to the signal receiving unit 200. Since continuous transfer of sensor 130 data consumes battery power, it may be more efficient to process the sensor data locally in the inertial sensor units 110, and only transfer signals to the signal receiving unit 200 if there is a need for this.

[0034] The signal receiving unit 200 is preferably arranged to communicate with at least one user device 150. The user device 150 may e.g. be a mobile device, such as e.g. a smartphone, a tablet, or a laptop. The communication may take place via a physical cable, via the mobile communication network, or via any other type of wireless communication supported by the user device, such as e.g. Bluetooth or Wi-Fi. The signal receiving unit 200 may comprise a computer that comprises input means and a display, but the signal receiving unit 200 may also be a device arranged to be controlled entirely via an application in the user device 150. The signal receiving unit 200 may comprise one or more alerting means, such as e.g. LED:s and / or audio emitters. It may be battery operated for easier placement, but preferably also comprises a power cord for connection to the electricity network. Fig. 2 schematically illustrates a scaffold 300, and Fig. 3 schematically illustrates a part of the scaffold 300. The scaffold 300 comprises vertical posts 310, 320 and horizontal floor units 330. In order for the scaffold 300 to stand firmly against a wall, it needs to be attached to the wall using wall mounting arrangements 340. There are often requirements as to the number and spacing of such wall mounting arrangements 340. The scaffold 300 illustrated in Fig. 2 e.g. has a wall mounting arrangement 340 attached to each inner vertical post 310, for every second floor.

[0035] The wall mounting arrangement 340 illustrated in Fig. 3 is a ring lock arrangement comprising a wall tie bar 360, attached to the inner vertical post 310 of the scaffold 300, and a wall mounted ring 350. Any type of wall mounting arrangement 340 may however be used, such as e.g. a bar directly screwed to the wall.

[0036] There may also be one or more further sensors, such as e.g. a wind speed sensor 140, attached to the scaffold 300.

[0037] In order to use the system 100 to determine whether a specific wall mounting arrangement 340 is loose, it is important that the system knows exactly which inertial sensor unit 110 that is associated with each wall mounting arrangement 340. The inertial sensor units 110 therefore preferably have ID numbers, that are entered into a database associated with the scaffold 300 during initiation of the system 100. This entering may be done manually, using a user interface accessible e.g. via a user device 150 that communicates with the signal receiving unit 200. There may be scannable codes, such as bar codes or QR codes, on the inertial sensor units 110, to facilitate initiation of the system 100. Alternatively, RFID tags may be used. One or more positioning systems (e.g. GPS), and / or altimeters, may also be used for positioning of the inertial sensor units 110.

[0038] It is however also possible to implement automatic initiation of the system 100. If it is possible to vary the strength of the signal for the communication between the inertial sensor units 110 and the signal receiving unit 200, this signal variation may be used to automatically make a map of the location of the different inertial sensor units 110. Alternatively, the time it takes for the signals to reach the signal receiving unit 200 could be used. If the inertial sensor units 110 are able to communicate directly with each other, their internal position pattern could also be determined in this way.

[0039] If the entire scaffold construction is very large, it may be suitable to monitor the safety of the scaffold construction using a number of different systems 100, where each system 100 monitors the safety of a scaffold 300 that is a part of the whole scaffold construction. The systems 100 may then be arranged to communicate with each other, but they may also be entirely separate from each other.

[0040] Fig. 4 illustrates a wall mounting arrangement 340 comprising a wall tie bar 360 and a wall mounted ring 350, and Figs. 5a-b illustrate an inertial sensor unit 110 that may be integrated into a bar of a wall mounting arrangement 340, such as into the wall tie bar 360 of Fig. 4. The illustrated inertial sensor unit 110 has the same elongated cylindrical shape as the wall tie bar 360, so that it fits snugly within the wall tie bar 360. This makes it easy to mount the inertial sensor unit 110 in the correct position within the wall tie bar 360. The inertial sensor unit 110 illustrated in Fig. 5b comprises a sensor 130 and a battery 135. The inertial sensor unit 110 may also comprise a processing device 120.

[0041] The inertial sensor unit 110 may comprise no other sensors 130 than an accelerometer, since this is enough to provide the desired functionality. However, the inertial sensor unit 110 may also comprise one or more further sensors 130, such as e.g. a gyroscope. The system 100 may also comprise one or more environmental sensors, such as e.g. a wind speed sensor 140. Such one or more environmental sensors may be arranged together with one or more inertial sensor units 110, but they may also be arranged separately.

[0042] The inertial sensor units 110 may be arranged to simply send data to the signal receiving unit 200. However, the inertial sensor units 110 may also be provided with two-way communication, so that the signal receiving unit 200 may send instructions to an inertial sensor unit 110. The inertial sensor unit 110 illustrated in Fig. 4 is also provided with alerting means 115, such as e.g. a LED. In this way, the inertial sensor unit 110 that is comprised in a wall mounting arrangement 340 that is loose may flash its LED to indicate the location of the loose wall mounting arrangement 340. If there is local signal processing in the inertial sensor unit 110, the processing device 120 in the inertial sensor unit 110 may determine that the associated wall mounting arrangement 340 is loose, and start flashing its LED. However, if there is two-way communication, the signal receiving unit 200 may also instruct the relevant inertial sensor unit 110 to flash its LED. The inertial sensor units 110 are preferably battery operated.

[0043] The variability of the acceleration may typically be measured in three axes by an inertial sensor unit 110. By comparing the acceleration in the different axes, and the acceleration measured by different inertial sensor units 110 comprised in different wall mounting arrangements 340, it is possible to determine which wall mounting arrangement 340 that is loose. There is typically a clear increase in variability in the acceleration in the direction perpendicular to the wall (the z direction) for the inertial sensor unit 110 that is comprised in a wall mounting arrangement 340 that is loose, especially compared to the vertical acceleration (the x direction). This is described in more detail in WO2023280666, and applies generally also when the inertial sensor units 110 are comprised in the wall mounting arrangements 340.

[0044] There are a number of different options for processing the signals from the inertial sensor units 110 in order to determine whether a specific wall mounting arrangement 340 is loose. For example, the ratio between the variability in the z direction and the variability in the x direction for the acceleration measured by an inertial sensor unit 110 may be used. If this ratio increases beyond a predetermined threshold, it is likely that the wall mounting arrangement 340 comprising the inertial sensor unit 110 is loose. Another option is to analyze the frequency content, e.g. using FFT (Fast Fourier Transform) analysis. If a wall mounting arrangement 340 is loose, the frequency of the acceleration signals measured by the inertial sensor unit 110 is likely to change.

[0045] In order to use this type of signal processing, it is advantageous if it can be ensured that all inertial sensor units 110 are mounted so that they are aligned with the coordinate system used. This may be ensured e.g. by markings on the inertial sensor unit 110 to indicate how it should be mounted in the bar 360, and how the bar 360 should be mounted in the wall mounting arrangement 340. The system 100 may also be arranged to automatically determine whether the inertial sensor units 110 are correctly mounted, based on gravity. If one or more inertial sensor units 110 are determined not to be correctly mounted, this information may be used either for alerting for incorrect mounting, or for calibrating the coordinate system based on the incorrect mounting.

[0046] Machine learning may also be used to evaluate the signals from the inertial sensor units 110. In this case, the exact mounting becomes less important. The system 100 may even be self-calibrating, using machine learning based on historical data received from the plurality of inertial sensor units 110. In this case, it is enough to collect signals from all the inertial sensor units 110 for a predetermined time when it is ascertained that no wall mounting 340 arrangement is loose, and then simply determine deviations from the normal operation.

[0047] It is also possible to create data for training a machine learning algorithm using a "reference scaffold”. Measurement data can then be collected with all wall mounting arrangements 340 tightly secured, and with one more specific wall mounting arrangements 340 loose. Different types of motion may be used for creating the measurement data, including physical movement of people on the scaffold. In this way, the machine learning algorithm may learn to separate movement caused by the environment from movement caused by people walking on the scaffold. This may be used to detect intruders on the scaffold, possibly in combination with methods of identifying authorized personnel, such as e.g. RFID tags.

[0048] If the system includes a wind speed sensor 140, the signals received from the wind speed sensor 140 may also be used to determine whether a specific wall mounting arrangement 340 is loose. The signals received from the wind speed sensor 140 may e.g. be used to calibrate the system. It may be determined in advance to what extent the wind speed affects the acceleration measured by the inertial sensor units 110, and based on such a determination, the acceleration may be calibrated based on the measured wind speed. The calculation of threshold values may also be based on the measured wind speed. If the at least one processing device 120 determines that a specific wall mounting arrangement 340 is loose, an alert may be sent to one or more persons responsible for the scaffold, preferably via communication with at least one user device 150. The signal receiving unit 200 may however also be arranged to alert users via alerting means arranged on the signal receiving unit 200, and / or on the inertial sensor unit 110 that is comprised in the wall mounting arrangement 340 that is loose.

[0049] Fig. 6 schematically illustrates a method 600 for monitoring the safety of a scaffold 300. The method 600 may comprise:

[0050] Step 670: arranging inertial sensor units 110 to be comprised in wall mounting arrangements 340 of the scaffold 300.

[0051] Step 690: determining, based at least on signals received from the inertial sensor unit 110 that is comprised in a specific wall mounting arrangement 340, whether said wall mounting arrangement 340 is loose.

[0052] This enables a determination of exactly which wall mounting arrangement 340 that is loose, without having to try to attach inertial sensor units 110 to the scaffold straight outside the wall mounting arrangements 340.

[0053] In embodiments, the arranging 670 comprises integrating the inertial sensor units 110 into bars, such as wall tie bars 360, of the wall mounting arrangements 340.

[0054] In embodiments, the method 600 further comprises at least one of the following:

[0055] Step 610: arranging the inertial sensor units 110 to comprise accelerometers 130. The processing of accelerometer signals is a simple yet reliable way of determining whether a wall mounting arrangement 340 is loose.

[0056] Step 620: arranging the inertial sensor units 110 to comprise alerting means 115, such as e.g. LED:s. In this way, the inertial sensor unit 110 that is comprised in a wall mounting 340 arrangement that is loose may flash its LED to indicate the location of the loose wall mounting arrangement 340. If there is local signal processing in the inertial sensor unit 110, the processing device 120 in the inertial sensor unit 110 may determine that the associated wall mounting arrangement 340 is loose, and start flashing its LED. However, if there is two-way communication, the signal receiving unit 200 may also instruct the relevant inertial sensor unit 110 to flash its LED.

[0057] Step 630: arranging the signal receiving unit 200 to comprise alerting means 115, such as e.g. LED:s and / or audio emitters. Even though such alerting means will not show which wall mounting arrangement 340 that is loose, this may be a more reliable way of indicating to users of the scaffold 300 that there is a problem. Step 640: arranging the signal receiving unit 200 to communicate with at least one user device 150. This enables the sending of alerts to one or more persons responsible for the scaffold 300.

[0058] Step 650: attaching at least one wind speed sensor 140 to the scaffold 300.

[0059] Step 660: arranging the signal receiving unit 200 to receive signals also from the at least one wind speed sensor 140. In this way, the determining 690 of whether a specific wall mounting arrangement 340 is loose may be based also on the signals received from said at least one wind speed sensor 140. This ensures that the signal analysis takes the wind excitation of the scaffold 300 into account.

[0060] Step 680: self-calibrating, using machine learning based on historical data received from the plurality of inertial sensor units 110. In this way, it may be automatically determined when there are deviations from the normal operation.

[0061] The foregoing disclosure is not intended to limit the present invention to the precise forms or particular fields of use disclosed. It is contemplated that various alternate embodiments and / or modifications to the present invention, whether explicitly described or implied herein, are possible in light of the disclosure. The system 100 may also be used for determining general movement of the scaffold, as an indication of something being out of the ordinary, even if it is not determined whether a specific wall mounting arrangement 340 is loose.

[0062] Further, not all of the steps of the claims have to be carried out in the listed order. All technically meaningful orders of the steps are covered by the claims. Accordingly, the scope of the invention is defined only by the claims.

Claims

CLAIMS1 . System (100) for monitoring the safety of a scaffold (300), comprising: a plurality of inertial sensor units (110), each inertial sensor unit (110) being comprised in a wall mounting arrangement (340) of the scaffold (300); a signal receiving unit (200), arranged to receive signals wirelessly from the plurality of inertial sensor units (110); and at least one processing device (120), arranged to determine whether a specific wall mounting arrangement (340) is loose, based at least on signals received from the inertial sensor unit (110) that is comprised in said specific wall mounting arrangement (340), wherein the inertial sensor units (110) are integrated into bars (360) of the wall mounting arrangements (340).

2. System (100) according to claim 1, wherein the system (100) is arranged to be self-calibrating, using machine learning based on historical data received from the plurality of inertial sensor units (110).

3. System (100) according to any one of claims 1 and 2, wherein at least one processing device (120) is located in the signal receiving unit (200).

4. System (100) according to any one of claims 1-3, wherein the inertial sensor units (110) comprise accelerometers (130).

5. System (100) according to any one of claims 1-4, wherein the inertial sensor units (110) comprise alerting means (115).

6. System (100) according to any one of claims 1-5, wherein the signal receiving unit (200) comprises alerting means (115).

7. System (100) according to any one of claims 1-6, wherein the signal receiving unit (200) is arranged to communicate with at least one user device (150).

8. System (100) according to any one of claims 1-7, further comprising at least one wind speed sensor (140), wherein the signal receiving unit (200) is arranged to receive signals also from the at least one windspeed sensor (140), and the at least one processing device (120) is arranged to determine whether a specific wall mounting arrangement (340) is loose based also on the signals received from said at least one wind speed sensor (140).

9. Method (600) for monitoring the safety of a scaffold (300), the method (600) comprising: arranging (670) inertial sensor units (110) to be comprised in wall mounting arrangements (340) of the scaffold (300), wherein the arranging (670) comprises integrating the inertial sensor units (110) into bars (360) of the wall mounting arrangements (340); and determining (690), based at least on signals received from the inertial sensor unit (110) that is comprised in a specific wall mounting arrangement (340), whether said wall mounting arrangement (340) is loose.

10. Method (600) according to claim 9, further comprising self-calibrating (680), using machine learning based on historical data received from the plurality of inertial sensor units (110).

11. Method (600) according to any one of claims 9 and 10, further comprising arranging (610) the inertial sensor units (110) to comprise accelerometers (130).

12. Method (600) according to any one of claims 9-11, further comprising arranging (620) the inertial sensor units (110) to comprise alerting means (115).

13. Method (600) according to any one of claims 9-12, further comprising arranging (630) the signal receiving unit (200) to comprise alerting means (115).

14. Method (600) according to any one of claims 9-13, further comprising arranging (640) the signal receiving unit (200) to communicate with at least one user device (150).

15. Method (600) according to any one of claims 9-14, further comprising attaching (650) at least one wind speed sensor (140) to the scaffold (300), and arranging (660) the signal receiving unit (200) to receive signals also from the at least one wind speed sensor (140), wherein the determining (690) of whether a specific wall mounting arrangement (340) is loose is based also on the signals received from said at least one wind speed sensor (140).

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