阅读说明：本技术 智能线缆传感器 (Intelligent cable sensor ) 是由 托雷·斯特兰德 于 2018-09-03 设计创作，主要内容包括：本发明涉及一种用于插入编织、编结和/或松弛的线缆内并测量编织、编结和/或松弛的线缆内的张力的传感器装置。该传感器装置包括具有外部壳体表面和内部壳体表面的细长的传感器壳体以及布置在该细长的传感器壳体内部的至少一个压力传感器。外部壳体表面具有围绕传感器壳体的纵向轴线的基本上椭圆或圆形的横截面区域。此外,至少一个压力传感器被构造成允许至少间接地测量施加在外部壳体表面上的压力。本发明还涉及用于系泊一个或多个结构的线缆传感器组件和调节线缆传感器组件中的张力的方法以及线缆传感器组件的用途。(The present invention relates to a sensor device for insertion and measurement of tension in a braided, braided and/or slack cable. The sensor device comprises an elongated sensor housing having an outer housing surface and an inner housing surface and at least one pressure sensor arranged inside the elongated sensor housing. The outer housing surface has a substantially elliptical or circular cross-sectional area about the longitudinal axis of the sensor housing. Furthermore, the at least one pressure sensor is configured to allow at least indirect measurement of the pressure exerted on the outer housing surface. The invention also relates to a cable sensor assembly for mooring one or more structures and a method of adjusting tension in a cable sensor assembly and use of a cable sensor assembly.)

1. A sensor device (1) for insertion into a braided, braided and/or slack cable (2) and measuring tension in the braided, braided and/or slack cable (2), the sensor device (1) comprising:

-an elongated sensor housing (3) having an outer housing surface (4) and an inner housing surface (5), the outer housing surface (4) having a substantially elliptical or circular cross-sectional area around a longitudinal centre axis of the sensor housing (3), and

-at least one pressure sensor (6) arranged inside the elongated sensor housing (3), the at least one pressure sensor (6) being configured to at least indirectly measure the pressure exerted on the outer housing surface (4).

2. Sensor device (1) according to claim 1, wherein at least one end (27,28) of the elongated sensor housing (3) in the longitudinal direction is removably connected to the sensor housing (3) by a fixing means (9) such that removal of the at least one end (27,28) of the elongated sensor housing (3) allows free access to the internally arranged at least one pressure sensor (6).

3. The sensor device (1) according to any one of the preceding claims, wherein the sensor device (1) further comprises:

-at least one temperature sensor (11) arranged within the sensor housing (3), the at least one temperature sensor (11) being configured to at least indirectly measure a temperature within a braided, braided and/or relaxed cable (2) at or near an insertion point (12) at which the sensor device (1) is inserted into the cable (2).

4. The sensor device (1) according to any one of the preceding claims, wherein the sensor device (1) further comprises:

-a data recording unit (13) arranged within the sensor housing (3) for recording data received from any of the at least one pressure sensor (6).

5. The sensor device (1) according to claim 4, wherein the sensor device (1) further comprises:

-a data recording unit (13) arranged within the sensor housing (3) for recording data received from the at least one pressure sensor (6) or the at least one temperature sensor (11) or a combination of both.

6. The sensor device (1) according to claim 4 or 5, wherein the sensor device (1) further comprises:

-a data transmission unit (14) arranged within the sensor housing (3) for transmitting a data signal (24) from the data recording unit (13) to an external receiver (15) during use.

7. The sensor device (1) according to claim 6, wherein the data transmission unit (14) comprises a wireless transmission device (16).

8. The sensor device (1) according to any one of the preceding claims, wherein at least one end of the elongated sensor housing (3) in the longitudinal direction comprises a core strand attachment device (33) for attaching a core strand (34).

9. A cable sensor assembly (17), wherein the cable sensor assembly (17) comprises:

-a braided, braided and/or relaxed cable (2), and

-at least one sensor device (1) arranged centrally within a braided, braided and/or relaxed cable (2), the at least one sensor device (1) comprising:

-a sensor housing (3) having an outer housing surface (4) and an inner housing surface (5), the outer housing surface (5) having a substantially elliptical or circular cross-sectional area around a longitudinal centre axis of the sensor housing (3), and

-a pressure sensor (6) arranged inside the sensor housing (3), the pressure sensor (6) being configured to at least indirectly measure a pressure exerted on the outer housing surface (4).

10. The cable sensor assembly (17) according to claim 9, wherein the at least one sensor device (1) is according to any one of claims 1 to 8.

11. A cable sensor assembly (17) according to claim 9 or 10, wherein the assembly (17) further comprises:

-first fixing means (30) arranged on the first structure (19),

wherein a first cable end (20) of the braided, braided and/or slack cable (2) is fastened to the first fixing means (30) and a second cable end (21) of the braided, braided and/or slack cable (2) is fixed to a second fixing means (32) arranged on a second structure (22).

12. A cable sensor assembly (17) according to any of claims 9-11, wherein the assembly (17) further comprises

-at least one data receiver (15) for receiving a data signal (24) from the at least one sensor device (1), an

-a control system (23) for processing the received data signal (24).

13. Cable sensor assembly (17) according to claim 11 or 12, wherein the first fixing means (30) comprise a winch arrangement (18) configured to

Receiving data relating to the tension from the at least one sensor device (1) in use, an

-rolling out or in, or keeping still, said braided, braided and/or slack cable (2) according to data and pre-programmed instructions received from said at least one sensor device (1) relating to said tension.

14. The cable sensor assembly (17) of claim 13, wherein the winch arrangement (18) comprises:

a data receiver (15) for receiving a data signal (24) from the at least one sensor device (1) in use,

-a winch motor (25) for reeling in or paying out the braided, braided and/or slackened cable (2) such that the cable tension changes, an

-a control system (23) for processing the received data signals (24) and controlling the reeling operation set by the motor (25).

15. A method of adjusting tension in a cable sensor assembly (17) according to any one of claims 9-14, the method comprising the steps of:

-measuring a pressure perpendicular to the longitudinal direction of the sensor housing (3) at least indirectly,

-transmitting data from the sensor device (1) to a winch device (18),

-processing said data in a control system (23), an

-determining whether the tension in the braided, braided and/or relaxed cable (2) should be adjusted according to pre-programmed instructions and processed data.

16. Use of a cable sensor assembly (17) according to any one of claims 9-14 for performing at least one of the following:

at least one of the floating structures is moored,

the towing of at least one of the floating structures,

adjusting at least one rigging cable on the sail, and

the subsea installation is lowered from the floating structure.

Technical Field

The present invention relates to a sensor device, an assembly and a corresponding method for measuring and controlling tension in a cable. More particularly, the present invention relates to a sensor device for a heavy load line, such as a mooring line, a cable sensor assembly and a method of adjusting tension in such an assembly.

Background

The life of cables used to secure, reduce and/or secure objects, such as in marine use, depends on a number of factors. The cyclic loads that are typically imposed on the cable in an offshore environment may cause some portions of the cable to fatigue. Other factors (e.g. temperature variations) and wear in the process may also affect the fatigue resistance of the cable.

Failure of such cables can have serious consequences. The fastened object may loosen, may move violently and collide with other objects or people. Especially when dealing with large floating structures, such as ships, the forces from breaking the cable can kill or injure bystanders.

As a result, such cables are often inspected for signs of damage or fatigue, the frequency of which is usually determined by agencies such as the ocemf (oil company international ocean forum), which have determined a series of rules for inspecting tanker cables, such as recording hours of use.

However, since the condition of the cable does not depend only on the number of hours of use, the frequency of inspection may be too low or too high compared to that required. Up to now, in the case of mooring lines on a ship, for example, the lines have been manually inspected by a crew. If the cable shows signs of damage or fatigue, it is usually replaced with a new cable. Manual inspection is time consuming and prone to human error. In addition, manual inspection cannot reveal that the cable is overloaded (i.e., the cable may be close to breaking), and manual inspection needs to be performed when the cable is not in use.

In order to avoid serious consequences that may be caused by cable faults, the inspection frequency and time are often excessive. This inevitably results in excessive time spent inspecting the cable, which valuable time could otherwise be spent on other tasks. Let alone cable replacement, which can be wasteful, leading to higher operating costs.

One known solution to this problem is to place a detachable sensor on or partially within the cable to measure the load acting on the cable during operation.

US patent application publication No. US 2011/0006899 discloses a sensor unit for measuring the load on a cable. In one embodiment, the sensor unit may be arranged at or at least partially within a cable (such as a belt). The sensor unit may be used in connection with anchoring/mooring and comprises a transmission device configured to transmit information to an external device. The transmitted information can then be used by the external device to enable the operator to observe possible critical conditions. However, since the sensor unit described in this application is asymmetric and is at least partially arranged outside the cable, its use is limited. In a cable on a device which is subjected to a rough process such as a winch, a hook hole, or other devices, a sensor unit disposed outside the cable may interfere with the device and be damaged. Although this application describes embodiments in which the sensor unit is detachable from the cable, detachment is only possible by detaching the sensor unit and/or the cable, which greatly complicates the installation of the unit.

Therefore, a solution is needed that can alleviate the drawbacks of the background art.

Disclosure of Invention

In view of this, it is an object of the present invention to provide a sensor device which can be inserted and used for measuring tension in various cables, in particular heavy load lines such as mooring lines. The sensor device is configured to measure and transmit data regarding the use of the cable, thereby reducing the frequency of inspecting and replacing the cable while minimizing the risk of the cable breaking.

Furthermore, it is an object of the present invention to provide a sensor device which can be easily placed in or removed from a cable.

Another object is to provide a sensor device that may comprise part of an intelligent cable sensor assembly, allowing self-adjustment of the tension in the cable.

Other objects will be apparent to those skilled in the art.

The invention is set forth and characterized in the main claims, while the dependent claims describe other characteristics of the invention.

Accordingly, the present invention relates to a sensor device for measuring tension in a cable, the sensor device comprising:

an elongated sensor housing having an outer housing surface and an inner housing surface, the outer housing surface having a substantially elliptical or circular cross-sectional area around a longitudinal center axis of the sensor housing, and

-at least one pressure sensor arranged inside the elongated sensor housing, the at least one pressure sensor being configured to at least indirectly measure a pressure exerted on the outer housing surface, the elliptical cross-sectional area being defined hereinafter as also comprising a circular cross-sectional area.

The invention thus provides a sensor device which can be arranged centrally within a cable, which sensor device is durable and therefore suitable for use with cables which are subjected to heavy loads, but which sensor device can also be easily deployed into and removed from the cable. The cable may comprise a braided cable, also referred to as a braided cable, or a loose cable, defined herein as a wire formed by twisting or twisting strands together. Such braided, braided and/or slack cables may typically include heavy duty ropes such as mooring ropes. The sensor device may have a shape making it particularly suitable for insertion into a braided, braided and/or relaxed cable, wherein it may be inserted into or pulled out of the cable by placing the device between the strands of the cable. The elongate shape of the sensor housing may also make it particularly suitable for remaining within a braided, braided and/or loose cable once inserted, as it has little effect on the strength of the cable and does not slip out of the cable due to the high radial forces acting on the housing by the strands of the cable during tensioning. The shape of the sensor device may be substantially shaped as an oblong ellipsoid, and at least a part of the maximum diameter D of the elongated sensor housing measured in a direction perpendicular to the centre line C of the housing longitudinal direction may be constant along at least a part of the housing longitudinal length L.

It is contemplated that the sensor device is also suitable for other kinds of elongated objects, such as ropes, cables, wires, belts, cables, or any kind of cable into which the device may be inserted, or combinations thereof. In prior art solutions, known sensor devices for measuring the tension in a cable are generally adapted to be integrated with the cable, which makes these prior art sensor devices unsuitable for insertion into braided, braided and/or slack cables.

By placing the sensor device inside the cable, the device can measure the compression due to the radial movement of the strands of the cable during tensioning, thereby indirectly measuring the tension in the cable. The cross-sectional area of the outer housing surface around the longitudinal centre axis of the centre housing is preferably circular, wherein the distance from the periphery to the centre point is constant at 360 degrees. However, other ellipses are possible, wherein the distance from the periphery to the center may be 5% to 10%, for example 5%, longer than the shortest distance from the periphery to the center.

Each sensor should be able to measure the compression due to the radial movement of the strands during tensioning of the cable. Based on the measured compression, the tension in the cable can be estimated/calculated. In one aspect of the invention, compression may be measured by a load cell disposed inside an elongated sensor housing. However, based on the disclosure of the invention herein, it will be apparent to those skilled in the art that other sensors, such as pressure gauges or similar pressure measuring devices, may also be used. In aspects, one or more load cells may be arranged for redundancy, and measurements compared to improve accuracy. The load cell may typically comprise a strain gauge, such as a foil strain gauge or a semiconductor strain gauge or other strain gauges known in the art. Strain gauges that can be calibrated with a preset initial stress can be used, allowing these strain gauges to be calibrated as needed during their life cycle. Preferably, strain gauges requiring a small amount of power can be used in the sensor device.

In one aspect of the invention, the elongated sensor housing may comprise a material having a young's modulus E, and the material and design of the outer housing surface may be configured in combination to support application of an average pressure of more than 1000 megapascals substantially perpendicular to the outer housing surface at a temperature of 293 kelvin over a period of 10 seconds without causing the sensor housing to crack. Thus, the elongated sensor housing may advantageously comprise a linear elastic material. The fracture resistance of the elongate sensor housing can also be defined by high load cycles, which can often lead to fatigue fractures. Such a break is defined herein as a break that is detectable, preferably by visual inspection. The period of time during which the sensor device is subjected to such compression may be, for example, between 10 seconds and 20 seconds. Preferably, the material may comprise a Young's modulus E of at least 30 GPa. A material with a high young's modulus may be preferred for cables that withstand high loads, while a material with a lower young's modulus may be more suitable for achieving less weight and improving the safety of smaller cables and cables that withstand lower loads. Preferably, the material may comprise aluminium having a Young's modulus of between 65GPa and 75GPa for withstanding cables of lower tension (e.g. 5 tonnes to 50 tonnes). For cables subjected to higher loads, a material comprising titanium with a young's modulus between 105GPa and 120GPa may be more suitable, or for even higher loads a material comprising steel with a young's modulus between 190GPa and 210GPa may be more preferred. In various aspects, yield strength, which is defined as the stress level at which a material begins to exhibit plastic deformation, can be an important factor in selecting a material for an elongated sensor housing. Advantageously, the sensor device is thus designed for heavy duty operations, such as mooring lines for ships, platforms and similar floating structures. These cables may typically be under tension of 10kN to 3000 kN. The elongated sensor housing may comprise several parts, wherein the material of each part may be different. Thus, the elongated sensor housing may comprise a material such as a hard plastic, polymer-based compound (including, for example, nylon, PEEK, POM, and fiber-reinforced composites).

In one aspect of the invention, an elongated sensor housing may include a middle portion, and two end portions removably connected to the middle portion. The middle portion may typically comprise aluminum, steel or titanium, and the end portions may comprise materials such as hard plastics, polymer-based compounds (including nylon, PEEK, POM and fibre-reinforced composites, for example). Preferably, the end portion may comprise a plastics material which allows wireless data signals to be transmitted from inside the sensor housing, while the intermediate portion comprises a material having sufficient strength to withstand high loads.

In one aspect of the invention, the end of the elongated sensor housing in the longitudinal direction may be rounded. Thus, the rounded end is preferably shaped to not include a sharp tip that could damage or weaken the cable. Thus, in certain aspects of the invention, the tip of the end may comprise a semi-circular shape having a radius of 1 mm, 2 mm, 3 mm, or 4 mm. To avoid wear on the cable, the elongated sensor housing may advantageously be smooth and free of any sharp protrusions, edges, kinks or other shapes that may damage the cable and/or affect the characteristics of the cable. In one aspect of the invention, the maximum diameter D of the elongated sensor housing, measured in a direction perpendicular to the housing longitudinal direction center line C, may be kept constant along at least 15% of the total longitudinal length L. The length M of the constant maximum diameter D may more preferably represent at least 5% of the total length L, for example 15% of the total length L. Alternatively, the diameter may not be constant such that the outer housing surface comprises a continuously curved shape. The design of the outer shell surface may also be defined by the following parameters with exemplary values:

the longitudinal length L of the outer surface of the sensor device is between 300mm-500mm, more preferably between 300mm-400mm, such as 300mm, 350mm or 400 mm.

The maximum diameter D of the outer surface of the sensor device housing is between 30mm and 70mm, more preferably between 30mm and 50mm, such as 30mm, 40mm or 50 mm.

An intermediate length M, defined as the distance along the outer shell surface between two planes in which the diameter D starts narrowing towards the shell termination point, wherein M may be between 15% and 90% of L,

-a ratio between the maximum diameter/length (D/L) of 1% to 20%, more preferably 2% to 15%, most preferably 4% to 8%, for example 5%.

-an angle θ between;

a line extending from an end point of the length M and perpendicular to the longitudinal centre line C of the housing, an

A straight line extending from an end point of the length M to the closest end point of the outer housing surface, wherein the angle θ is at least 70 degrees, preferably at least 80 degrees, even more preferably at least 85 degrees, such as 87 degrees.

Based on the disclosure of the invention herein it will be apparent to a person skilled in the art that the design of the outer surface hull can also be adapted to certain kinds of cables, injecting heavy duty mooring lines braided with e.g. twelve strands. A large diameter may make the sensor prone to weakening the cable and also increases the force acting on the sensor from the cable, so a small diameter sensor is preferred. The intermediate portion of the elongated sensor housing may generally extend a length M with a constant maximum diameter D, and the detachable end portion may extend from a termination point of the outer housing surface to the intermediate portion. The detachable end portion may also generally form a portion of the length M, as the connection between the intermediate portion and the detachable end portion may overlap and form a portion of the constant diameter D.

In one aspect of the invention, at least one end of the elongated sensor housing in the longitudinal direction may be detachably connected to the sensor housing by a fixing means, such that the detachment of the at least one end allows free access to the internally arranged at least one pressure sensor. In certain aspects, only one end of the longitudinal housing is releasably connected. In a further aspect, the two ends are releasably connected, which may advantageously allow the sensor device to be detached from the two ends to access the device inside the housing, which may be beneficial if one end of the longitudinal housing is damaged and not opened. The sensor device may need to be disassembled to repair or replace the device located inside the sensor housing. In some aspects of the invention, the recorded data may be retrieved by disassembling the sensor housing. The securing means may comprise bolts, screws, glue, hinges, vulcanized rubber or any other securing means known in the art and which are capable of withstanding the forces exerted on the sensor device during use. In some aspects of the invention, the detachable end of the elongated sensor housing in the longitudinal direction may comprise a material having a different young's modulus than the sensor housing, preferably the material of the detachable end has a young's modulus higher than 2 GPa.

In one aspect of the invention, the outer housing surface may comprise a plurality of grooves, wherein each groove may have a design adapted to receive a strand when the sensor device is centrally inserted into a braided, braided and/or slack cable. Advantageously, since the groove is configured to receive the innermost strand of the cable, the groove may reduce local stresses on the housing, thereby causing the strand to protrude outward from the radial center of the cable, and also to contact the housing. Thus, more strands in contact with the shell ensure a more even distribution of pressure on the shell. In addition, the groove may prevent the sensor device from sliding up and down the longitudinal axis once the sensor device is placed within the cable. Since different cables may have different sizes and strand counts, the grooves may be sized at corresponding angles, intervals, depths and widths as appropriate for the particular type of cable.

In one aspect of the invention, the sensor device may further comprise at least one temperature sensor arranged within the sensor housing. The at least one temperature sensor may be configured to at least indirectly measure a temperature within the braided, braided and/or relaxed cable at or near the insertion point of the sensor device into the cable. Preferably, the at least one temperature sensor is located within the sensor housing such that it can measure the temperature of the cable as a function of time. This data needs to be collected since the life of the cable may depend on its exposure to different ambient temperatures. Temperature sensors may also be used to calibrate the pressure sensor measurements, as pressure sensor measurements (e.g., load cells) may be affected by thermal expansion of the sensor device housing. Thus, in calculating the tension in the cable, the temperature measurement can be used to compensate for any effects that may result from thermal expansion.

In one aspect of the invention, the sensor device may further comprise a data recording unit arranged within the sensor housing for recording data received from any of the at least one pressure sensors. Preferably, the data recording unit measures the pressure as a function of time. It will therefore be possible to collect this data and compare it with the condition of the cable, which may provide valuable insight into how the tensioning affects the life of the cable. When the sensor housing is detached, the data recording unit can be directly accessed by connecting the data recording unit to an external device such as a personal computer via, for example, a USB connection.

In one aspect of the invention, the sensor device may further comprise a data recording unit arranged within the sensor housing for recording data received from the at least one pressure sensor or the at least one temperature sensor or a combination thereof. Preferably, the data recording unit also measures the temperature as a function of time. It will therefore be possible to collect these data and compare them with the condition of the cable, which can provide valuable insight into how temperature and tension affect the life of the cable.

In one aspect of the invention, the device may further comprise a data transmission unit arranged within the sensor housing for transmitting data from the data recording unit, or data measurements by any of the pressure or temperature sensors, to an external receiver during use. The data transmission unit may also be configured to receive a data signal from an external transmitter during use. Preferably, the data transmission unit and other electronic components such as the data logging unit and sensors may be coupled to a power source such as a battery, although all internal devices may have their own battery or batteries otherwise shared. The external receiver may be arranged on a structure to which the cable is fixed. In some aspects of the invention, the data transmission unit may be connected to the external receiver via a wire, which may be arranged in or beside the cable. In one aspect of the invention, the data transmission unit transmits data directly and continuously from the sensor to the external receiver, which advantageously allows real-time adjustment based on the data. In other aspects, the transmission unit may be configured to transmit the recorded data from the data recording unit, since the continuous transmission of data may be relatively power consuming. Depending on the desired battery life, storage/recording capacity and the need for real-time measurements, data can be transmitted at 1 second, 5 seconds, 10 seconds, 20 seconds, 30 seconds, 40 seconds, or 50 seconds intervals or at 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 10 minutes, 20 minutes, 30 minutes, 40 minutes, or 50 minutes intervals, or at 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 12 hours, or 24 hours intervals. However, in general, data may be transmitted at intervals of 10 seconds to 3 minutes (e.g., 1 minute). In other aspects, the transmission unit may be configured to transmit data at given intervals while also being configured to transmit data immediately if a given parameter (e.g., a critical tension in the cable) is reached. The transmission unit may also be configured to transmit data instantaneously, independent of a given interval, for example if the tension in the cable changes a given parameter, for example a tension change equal to or greater than 0.5 ton, 1 ton, 1.5 ton or any other given parameter. In some configurations, the transmission unit may be configured such that it only transmits signals when it detects an external receiver, and may be configured to detect an external receiver at given intervals. Thus, the sensor device may minimize its battery usage, which may be advantageous in configurations where the sensor device does not include a data logging unit. The data recording unit and the data transmission unit may each be arranged to process measurement data from the sensor to determine whether the above-mentioned parameters have been reached. The device in the sensor device may be further configured to: if any sensor or recording unit fails or needs to be replaced, or the battery is low, a signal is sent via the data transmission unit.

In aspects, the sensor device may be configured to send and receive signals to a plurality of external receivers, which may be arranged such that there is redundancy to the sensor device if one external receiver cannot be connected to the sensor device, for example, if the external receiver is not operational. In aspects, a sensor device may be configured to transmit and receive signals from other sensor devices. Thus, if one sensor device is unable to reach an external receiver, multiple sensor devices may operate as a mesh network of nodes to relay data signals, thereby providing greater redundancy in the system of sensor devices.

The external receiver may relay the data signal using a wireless transmission device such as WiFi and/or through an electronic cable or device. For example, an external receiver arranged on the vessel may use the on-board power supply network to transmit data signals from the external receiver to a control unit or system arranged, for example, on the bridge of the vessel.

In an aspect of the present invention, the data transmission unit may include a wireless transmission device. In one aspect, acoustic transmission may be used, for example, in an underwater environment, such as a mooring for a floating platform or an aquaculture facility. The wireless transmission means may comprise bluetooth technology such as bluetooth 4, bluetooth 5, WiFi, LoRa WiMax, ZigBee, or other similar known technologies or combinations for wireless transmission in the internet of things. Preferably, the wireless transmission means may comprise bluetooth 5 technology, as this provides the ability to transmit signals over long distances while having relatively low battery consumption. In aspects, the data transmission unit may comprise a SIM card, thereby enabling transmission of data signals via a mobile technology network.

In an aspect of the invention, at least one end of the elongated sensor housing in the longitudinal direction may comprise a core strand attachment means for attaching the core strand to the elongated sensor housing. Advantageously, the at least one core strand attachment device attached to the core strand may prevent the sensor device from jumping out of the center of the braided, braided and/or relaxed cable when exposed to high compressive forces. In some aspects, the sensor device may have several core strand attachment means at different points on the outer surface shell, e.g. such that the sensor device may be attached to two core strands at both ends of the elongated sensor shell in the longitudinal direction.

In one aspect of the invention, the core strand attachment means may comprise a through hole for passing the core strand therethrough. Advantageously, the core strand may thus be attached to the sensor device without the need for knotting or splicing at the attachment device.

In one aspect of the invention, at least one end of the elongated sensor housing in the longitudinal direction may be detachably connected to the sensor housing by a fixing means, such that the detachment of the at least one end of the elongated sensor housing may allow free access to the internally arranged at least one pressure sensor, and wherein the core strand attachment means may present at least one core strand receiving channel extending into the at least one detachably connected end of the elongated sensor housing, the end of the channel may present an end portion having a larger average radial diameter than the rest of the channel. A larger average radial diameter may preferably increase the average radial diameter by up to 15%, most preferably by up to 25%, for example by 20%. Thus, the end of the channel may comprise a volume adapted to accommodate a knotted or spliced end of the core strand or other means for attaching the end of the core strand to the sensor housing, and wherein the core strand extends out of the channel and to a connection point with a regular strand in the cable.

In one aspect of the invention, the end portion of the channel may be a blind hole.

The invention also relates to a cable sensor assembly. The cable sensor assembly includes:

braided, braided and/or relaxed cables, and

-at least one sensor device arranged centrally within the braided, braided and/or relaxed cable.

At least one sensor device comprising: a sensor housing having an outer housing surface and an inner housing surface, and a pressure sensor disposed inside the sensor housing. The pressure sensor is configured to at least indirectly measure a pressure exerted on the outer housing surface. Furthermore, the outer housing surface has a substantially oval or circular cross-sectional area perpendicular to the longitudinal center axis of the sensor housing, for example a rotationally symmetrical design around the longitudinal axis of the sensor housing.

In aspects, the cable sensor assembly may include a first sheath, such as a plastic mesh sheath, disposed between the sensor device and the strands of the braided, and/or relaxed cable. The first sheath may increase the friction between the sensor device and the strands of the cable, thereby preventing any slipping of the sensor device within the cable, and also preventing the sensor device from being thrown away at high speed in case of a cable break.

In various aspects, the cable sensor assembly may include a second sheath, such as canvas, disposed about the braided, and/or slack cable in which the sensor device is disposed. The second sheath can prevent the sensor device from being thrown away at high speed in case of a cable break.

Advantageously, the sensor device may be designed for a specific kind of cable, giving an optimal assembly. In some aspects of the invention, the assembly may be used for mooring. However, mooring is herein understood to be securing a cable between at least one structure and another object (typically a floating structure). In a more specific aspect, such floating structure may comprise a ship, a floating platform, or a barge. However, the invention may in other aspects also be suitable for lowering objects from a floating structure, for example a subsea module to the seabed by means of a suitable crane.

In one aspect of the invention, the at least one sensor device of the cable sensor assembly may be associated with any of the above aspects of the sensor device.

In one aspect of the invention, the assembly may further comprise:

-a first fixation device arranged on the first structure, wherein a first cable end of the braided, braided and/or slack cable is fastened to the first fixation device and a second cable end of the braided, braided and/or slack cable is fixed to a second fixation device arranged on the second structure. The fixing means may comprise a static fixing means such as a bollard or a dynamic fixing means capable of being winched, such as an anchor puller. In a particular example, the securing means comprises a bollard located on both the onshore structure and the floating structure. Alternatively, the securing means comprise one winch arranged on the first structure and a bollard arranged on a second floating structure at a distance from the first structure.

In an aspect of the invention, the assembly may further comprise: at least one data receiver for receiving data signals from the at least one sensor device, and a control system for processing the received data signals. Preferably, the data receiver and the control system are arranged together, for example on one of the structures. It will be apparent to those skilled in the art that the data receiver in the cable sensor assembly may comprise the above-described external receiver and external transmitter, the data transmission unit being arranged to transmit and receive data signals thereto. In some aspects, the data receiver and control system may comprise a portable system, such as a laptop computer, mobile phone, or other handheld device.

In one aspect of the invention, the first securing means may comprise a winch arrangement configured to receive tension related data from the at least one sensor means in use and to wind it in or let out braided, braided and/or slack cable or to remain stationary in accordance with the tension related data received from the at least one sensor means and pre-programmed instructions. Alternatively, if the tension is found to be satisfactory, the winch arrangement may remain inactive.

Advantageously, the assembly may thus be self-adjusting, so that potentially dangerous high levels of tension in the cable can be avoided. Furthermore, the winch arrangement is capable of adjusting the cable to achieve a constant desired tension or to avoid repeated occurrences of high levels of tension which may reduce the life of the cable.

In one aspect of the present invention, the winch apparatus may include:

a data receiver for receiving data signals from at least one sensor device in use,

-a winch motor for reeling in or paying out a braided, braided and/or slackened cable for changing the cable tension, an

-a control system for processing the received data signals and controlling the reeling operation set by the motor.

In an aspect of the present invention, the cable sensor assembly may further include:

-at least one core strand attached to a strand of a braided, braided and/or relaxed cable,

at least one end of the elongated sensor housing in the longitudinal direction comprises a core strand attachment means, and wherein

-attaching at least one core strand to a core strand attachment device, thereby securing the sensor device to the braided, braided and/or relaxed cable. In an aspect of the invention, the braided, braided and/or relaxed cable may comprise at least one core strand fixedly attached to the sensor device. The at least one core strand may preferably be braided in or attached with other strands in a braided, braided and/or relaxed cable. Advantageously, the core strand may be an additional one of the braided, braided and/or relaxed cables and comprise a different material than the other strands in the cable. The core strand may preferably be designed to prevent the sensor device from jumping out of the center of the braided, braided and/or relaxed cable when exposed to high compressive forces.

Furthermore, the present invention relates to a method of predicting at least one integrity of a cable in a cable sensor assembly according to any of the above aspects, the method comprising the steps of:

-measuring the pressure in a longitudinal direction perpendicular to the sensor housing at least indirectly,

-recording data measured by the pressure sensor after 100 hours or more of use,

-transmitting the recorded data from the sensor device to a data receiver,

-processing data in a control system, and

-estimating one or more integrity of the braided, braided and/or relaxed cable based on the processed data and pre-programmed cable parameters. The data may be stored within the sensor housing or in an external storage medium or a combination thereof.

Advantageously, statistical information about the use of the cable can thus be collected and used for predicting the lifetime of the cable. The period of recording data may be determined by the storage capacity of the recording means in the sensor means and may be in the range of 100 hours to 10000 hours, for example 1000 hours, of use. In other aspects, the storage capacity of the recording device is sufficient to record data throughout the life cycle of the cable, especially if the sensor is fully integrated, i.e. remains in the cable throughout its life cycle. The pre-programmed cable parameters may include information about previous use of the cable and its initial integrity, i.e. statistics on the number of hours of use and changes in tension and/or temperature experienced during use, thickness and material selection of the strands in the cable, maximum working strength, breaking strength and how parameters such as tension and temperature over time affect the integrity of the cable. Thus, the assessment of cable integrity will be a function of the cable integrity prior to use and how it is affected by exposure to the above parameters when in use. A reduction in the remaining rope capacity can also be indicated by measuring whether the rope tension has exceeded a certain percentage of the defined rope MBL (minimum breaking load), for example 50%, 60%, 70% of the rope MBL.

Furthermore, the invention relates to a method of adjusting tension in a cable sensor assembly according to any of the above aspects, the method comprising the steps of:

-measuring the pressure or any vertical component of the pressure at least indirectly in a direction perpendicular to the longitudinal direction of the sensor housing,

-transmitting data from the sensor means to the winch means,

-processing data in a control system, and

-determining whether the tension in the braided, braided and/or relaxed cable should be adjusted based on pre-programmed instructions and processed data.

The pre-programmed instructions may be set according to the type of cable used in the assembly and the tension to which the design is subjected. Other pre-programmed instructions may include the above-mentioned pre-programmed cable parameters, as well as data relating to the previous life of the cable, e.g. how long it has been used, at what tension and temperature (which may be helpful in estimating the condition of the cable) and how much tension it may be subjected to, or when it should be replaced.

Furthermore, the invention relates to a method of inserting a sensor device into a braided, braided and/or relaxed cable comprising at least three strands, the method comprising the steps of:

-inserting the sensor device between the strands of the cable such that the sensor device is centered within the strands of the cable and arranged in the longitudinal direction of the cable. By arranging the sensor device within the centre of the strand, the sensor may measure the compression due to radial movement of the strand during tensioning.

In one aspect of the invention, the method may comprise the steps of:

-determining an insertion point along a braided, braided and/or relaxed cable, and

creating an opening between the two strands at the insertion point, the opening being of a size sufficient to insert the sensor device centrally within the strands,

-wherein the step of identifying an insertion point along the braided, braided and/or relaxed cable and forming an opening between the two strands may be performed before the step of inserting the sensor device. In an aspect of the invention, wherein the sensor device may be according to any of the above aspects, the method may further comprise the step of arranging the strands to fit within grooves of the outer housing surface.

With the former approach, the data may be stored within the sensor housing or in an external storage medium or a combination thereof.

Further, the present invention relates to the use of a cable sensor assembly according to any of the above aspects for performing at least one of the following operations:

at least one of the floating structures is moored,

the towing of at least one of the floating structures,

at least one rigging cable on the adjusting sail, and

the subsea installation is lowered from the floating structure.

Throughout the description and the claims, different words and terms are used, the definition of these and other features of the invention will become clear from the following description of a preferred form of embodiment, given as a non-limiting example, with reference to the accompanying drawings, in which;

drawings

FIG. 1 illustrates an aspect of the present invention in which a sensor device is shown centrally disposed within a braided cable.

Fig. 2 illustrates an aspect of the present invention in which a braided cable is shown along with possible insertion points for a sensor device.

Fig. 3 schematically illustrates an aspect of the invention in which the sensor device is arranged centrally within a braided, braided and/or relaxed cable, which is under tension, resulting in radial compression.

FIG. 4 schematically illustrates an aspect of the invention in which a sensor device having aspects of its dimensions is shown.

Fig. 5 schematically illustrates an aspect of the invention, showing the sensor device in a disassembled state.

Fig. 6 schematically illustrates an aspect of the invention, showing the sensor device in an assembled state.

Fig. 7 schematically illustrates an aspect of the invention in which the outer housing surface of the sensor device exhibits a plurality of grooves.

Fig. 8 schematically illustrates an aspect of the invention, in which an example of a sensor device comprising a core strand attachment device is shown.

Fig. 9 schematically illustrates an aspect of the invention, showing another example of a sensor device including a core strand attachment device.

FIG. 10 schematically illustrates an aspect of the invention in which a cable sensor assembly including a cable and a sensor device is disposed between two structures.

Fig. 11 shows the measurements collected during the sensor device test, which compares the measured tension of the sensor device with the actual tension in the cable.

Detailed Description

The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings.

In fig. 1, an aspect of the invention is shown, wherein a sensor device 1 of the invention is arranged centrally within a braided cable 2, as is the case during use of the sensor device 1. The braided cable 2 in fig. 1 comprises twelve strands 18. However, the cable 2 may comprise any number of strands 18 as long as the sensor device 1 may be arranged centrally therein.

Fig. 2 also shows a braided cable 2 comprising 12 strands, but without the sensor device 1 installed. The strands 18 of the cable are shown pulled apart, thereby providing openings between the strands 18 sufficient for insertion of the sensor device 1. When the sensor device 1 is to be deployed, the insertion point 12 must first be identified along the cable. The insertion point 12 may be located anywhere along the cable and will typically be selected on a case-by-case basis, depending, for example, on the distance between the sensor device 1 and the external receiving unit 15 to which the sensor device 1 is configured to send signals. Other considerations for selecting the insertion point 12 may include avoiding potential damage to the sensor device 1, i.e. by selecting an insertion point where the sensor device is less likely or less likely to collide with external objects.

At the insertion point 12, the strands 18 of the cable 2 separate as indicated by the arrows shown in fig. 2, for example by applying an external radial force (i.e., in the direction of the arrows) and/or by longitudinally compressing the cable 2. These actions provide the necessary opening large enough through which the sensor device 1 can be fully inserted in the center of the cable 1.

In one embodiment, the sensor device 1 may present a plurality of grooves 10 arranged in the outer housing surface 4, as shown in fig. 7. In this embodiment, the groove 10 is preferably shaped to suit the design of the particular cable 2 in use. For example, each groove 10 may be manufactured with respect to size, shape, spacing, depth, and angle to accommodate the arrangement and size of the surrounding strands 18. After insertion of the sensor device 1 with the groove 10, the sensor device 2 and/or the strands 18 may be adjusted such that at least one of the strands fits into the groove 10.

The data transmission unit 13 in the sensor device 1 may be configured to be signally connected to an external receiver 15 via wires. In this particular arrangement, the wires are connected to the device 1 and may be arranged inside the cable 2 and/or along the outside of the cable 2 after the sensor device 1 has been inserted into the wire cable 2. In an alternative arrangement, the transmission unit 13 may comprise an internal antenna, which is signal connected to the external receiver 15. In some aspects, the antenna may be configured to extend out of the sensor device 1, or to be mounted on the sensor device 1 after being inserted into the cable 1. In addition, an antenna may extend between the strands 18 to enable more efficient transmission of data signals.

Fig. 3 schematically shows the forces acting on the cable 2 and the sensor device 1 during use. The cable tension is represented by two arrows, which are two forces acting in substantially opposite directions along the longitudinal axis of the cable 2. These two opposing forces cause a radial contraction of the cable 2 about the longitudinal axis, resulting in a compression of the sensor device 1 arranged inside the cable 2. Thus, by directly or indirectly measuring the amount of compression on the sensor device 1, the tension in the cable 2 can be calculated/estimated.

Fig. 4 shows an aspect of the invention, wherein the contour view of the outer housing surface 4 is presented in an assembled state, perpendicular to the longitudinal axis of the housing 4. Labels D, M, L, C and θ denote:

a diameter D along the thickest part of the outer shell surface 4,

a length M of the sensor outer housing surface 4 having a substantially constant diameter,

the total length L of the sensor outer housing surface 4,

a centre line C of the sensor outer housing surface 4 extending in the longitudinal direction, an

-the angle θ between the two;

a line extending from an end point of the length M and perpendicular to the longitudinal centre line C of the housing, an

A straight line extending from the end point of the length M to the nearest end point of the outer shell surface.

Preferably, the shape of the outer housing surface 4 is optimized to withstand the compressive forces of the cable 2 during use, while causing minimal disturbance to the normal function of the cable 2 and avoiding the sensor device 1 to slip out of the cable 2. Thus, the outer housing surface 4 is elongated and rotationally symmetric about a centre line C defined by the longitudinal axis of the sensor device 1. As shown in fig. 4 to 7, the outer housing surface 4 comprises an elongated cylindrical shape, wherein the ends of the elongated sensor housing are rounded 7, 8 in the longitudinal direction.

The curvature of the ends of the elongated sensor housing in the longitudinal direction 7, 8 is preferably not linear, but rounded so that damage to the cable 2 from edges or sharp points is minimized. Thus, the end of the elongated sensor housing in the longitudinal direction may comprise a semicircular shape with a radius of 1, 2, 3 or 4 mm. The curvature is also arranged to withstand shear forces while preventing the sensor device 1 from jumping out of the centre of the cable 2 under compression.

Furthermore, the design of the elongated sensor housing 3 in combination with the material from which it is made enables the sensor device 1 to withstand the extreme forces that may occur during use. The compression of the strands 18 may result in an average pressure of over 1000MPa applied substantially perpendicularly to the outer housing surface 4 at 293 ° K. Thus, the elongated sensor housing 3 preferably comprises a steel, aluminum or titanium material. The young's modulus E of the material should therefore be at least 30GPa, for example between 65GPa and 75GPa for cables subjected to relatively low tensions, for example 5 to 50 tonnes. For cables subjected to higher loads, titanium-containing materials with a Young's modulus between 105GPa and 120GPa are more suitable, or for higher loads, materials containing steel with a Young's modulus between 190GPa and 210GPa are more suitable. The elongated sensor housing 3 is preferably designed to cope with temperature variations in the range from 273 ° to 320 ° kelvin while being subjected to these mechanical forces. Larger allowable temperature ranges are also contemplated.

The length L of the sensor device 1 may be 300mm to 500mm depending on the size of the cable 2 and under what conditions the cable is used. Likewise, depending on the size of the cable 2 and its use, the sensor device 1 may have a maximum diameter D of 30mm to 70mm, for example 30mm, 40mm, 50mm, 60mm or 70 mm. The relation between the maximum diameter/length D/L may preferably be between 2% and 8%, e.g. 5%.

As mentioned above, the outer surface 4 of the sensor housing 3 has the largest diameter D. The maximum diameter D is preferably constant or nearly constant for a length M measured along a radially centered longitudinal axis of the outer housing surface 4. Furthermore, the length M is at least 5%, for example 15%, of the total longitudinal length L of the outer shell surface 4. The optimal length M depends on the particular cable 2 in which the sensor device 1 is to be used. Alternatively, the diameter may not be constant such that the outer shell surface comprises a continuously curved shape and M is 0%. It should also be noted that the constant maximum diameter D is measured as if there were no grooves 10 on the outer housing surface 4. The angle θ is preferably at least 85 °, for example 87 °.

Other variants and combinations of sensor devices 1 with different dimensions can be designed for a certain type of cable 2. However, since they are too numerous and will be apparent to those skilled in the art based on the disclosure of the invention herein, they will not be further explained or illustrated herein. Accurate testing under realistic and representative conditions may reveal D, M, L, C and an optimal value for θ.

Fig. 5 shows a sensor device 1 in which the elongated sensor housing 3 is divided into three parts, two end parts 27,28 and an intermediate part 26. These parts are shown in different diagrammatic perspective views in fig. 5a, 5b and 5 c. The different parts can be detached by means of a fixing device 9, which fixing device 9 is illustrated in fig. 5b as a cylinder for accommodating screws or the like. The end portions 27,28 may comprise a different material than the intermediate portion, preferably a material having a lower young's modulus than the intermediate portion 26, for example a young's modulus of at least 2 GPa.

Fig. 5a shows the first end portion 27 at two different angles; a cross-sectional view perpendicular to the longitudinal axis and a cross-sectional view of the longitudinal axis. In a vertical view, the inner housing surface 5 is shown with staple lines, which extend a distance from the edge of the first end portion 27. Although not shown in fig. 5a, the first end portion 27 further comprises a fixation means 9 for attachment to the intermediate portion 26. The first end portion 27 and the intermediate portion 26 may also comprise means such as sensor units.

Fig. 5b shows the middle portion 26 from three different perspectives;

-perpendicular to the longitudinal axis,

-a cross-section along the longitudinal axis, and

three-dimensionally sideways.

In vertical view, the inner housing surface 5 is shown with staple lines extending from edge to edge through the intermediate portion 26. The cross-sectional view and the three-dimensional view show the fixing means 9 for attachment to the end portions 27, 28. Although not shown in fig. 5b, the intermediate portion 26 may also include components such as sensor units.

Fig. 5c presents the internal components of the sensor, schematically shown in dashed lines within the second portion 28. The pressure sensor 6 and the temperature sensor 11 record the compression and the temperature, respectively, and the information is recorded by the data recording unit 13. The data logging unit 13 preferably comprises some processing capability to estimate the tension in the cable 2 and to determine that one or more signals need to be sent immediately to the sending unit 14, e.g. due to excessive tension in the cable 2. Otherwise, the recording unit 13 may store the data received from the sensors 5, 6 for a certain time before sending the data to the sending unit 14. Typically, data regarding excessive tension is temporarily stored and can be overwritten, with data collected over a longer time frame being stored. The transmission unit 14 may comprise a wireless connection and/or an antenna for wireless transmission and is configured to transmit data to an external receiver 15. Furthermore, a power supply 29 (e.g. a battery) for powering the internal devices of the sensor device 1 is preferably also comprised inside the elongated sensor housing 3. Connection means for data transmission, such as a USB port or the like, may also be included inside the elongated sensor housing 3. When the sensor device 1 is in the detached state, connection means for data transmission may be used, for example for transmitting data from the data recording unit 13 and/or for configuring/reconfiguring internal devices.

It should be noted that although the outer housing surface 4 is rotationally symmetric, the inner housing surface 5 may comprise different shapes, volumes and cavities. The shape of the inner housing surface 5 is determined by considerations such as the strength requirements of the sensor device 1 to withstand external pressure, the space and arrangement requirements of the inner device. As shown in fig. 5b, the cross-section of the intermediate portion 26 has a varying wall thickness, so that a thicker portion of the wall can accommodate the fixation device 9. The deflection of the stadium-shaped inner longitudinal hollow section of the middle section 26 in the direction of deflection of the control housing, i.e. in the direction of the load measuring device, for example a strain gauge, may be advantageous.

The arrangement in fig. 5 is schematic and for illustrative purposes only, many variations of the internal volume and different configurations of the internal device are possible and will be apparent to those skilled in the art based on the disclosure of the invention herein.

Fig. 6 schematically shows another embodiment of the invention, in which the intermediate portion 26 of the elongated sensor housing 3 is longer than in the embodiment shown in fig. 5, and the two detachable end portions 27,28 have substantially similar lengths. The fixture 9 is arranged across two detachable parts 27,28 and the intermediate part 26, shown with staple lines in fig. 6. Although not limited to the example shown in fig. 6, a typical fixture 9 preferably comprises an arrangement in which: the screws are screwed into threaded holes between the detachable parts 26, 27,28, which screws can be screwed in the longitudinal direction of the external sensor housing 4 in recesses on one end portion of the elongated sensor housing by means of screw tightening means. In other constructions, the securing device 9 may include threads on the removable portions 27,28 and the intermediate portion 26 that are configured to engage one another, thereby allowing the removable end portions 27,28 to be threaded onto the intermediate portion 26.

The intermediate portion 26 may in some aspects have a constant diameter D, forming a cylindrical shape, while the detachable end portions 27,28 taper towards their respective termination points on the longitudinal axis of the elongate sensor housing 3. The intermediate portion 26 may generally comprise a material configured to withstand high loads, such as steel, aluminum, and/or titanium. The removable end portions 27,28 may comprise a material having a relatively low resistance to high loads, but rather be formed of plastic or other material, thereby allowing signals to be wirelessly transmitted through the removable end portions 27, 28. Therefore, it may be preferred to place the antenna at least towards each detachable end portion 27,28, even more preferably the antenna extends into the detachable end portion 27, 28.

Fig. 7 schematically shows an outer housing surface 4 presenting a plurality of grooves 10. The number of grooves 10 and their angle with respect to the longitudinal axis of the sensor device 1

The spacing S, width W and depth B may vary depending on the particular cable 2 to which the sensor device 1 is to be mounted. The shape of the recess 10 is preferably a semicircular cut with rounded edges to avoid any cutting or abrasion on the cable 2. The function of the groove 10 is to distribute the pressure more evenly over the outer surface casing 4 and to provide a better grip for the strands 18 to avoid slippage of the sensor device 1 within the cable 2. Depending on the particular type of cable 2 to be used, it will be apparent to those skilled in the art that other modes than that shown in the example of fig. 7 may also be used.

Fig. 8 shows a sensor device 1 with a core strand attachment 33, which core strand attachment 33 comprises a through-hole in the longitudinal direction at both ends 27,28 of the elongated sensor housing 3. The staple line through the hole shows how the at least one core strand 34 is passed through the core strand attachment means 33. In some aspects, one core strand 34 may pass through both core strand attachments 33, but there may be multiple core strands 34, or only one core strand attachment 33 and one corresponding core strand 34.

Fig. 9 shows another aspect of the core strand attachment means 33, wherein the ends 27,28 of the elongated sensor housing 3 in the longitudinal direction are removably connected. After the ends 27,28 of the shell are removed, the core strand 34 is passed through the channel and knotted or spliced at its ends or secured with an attachment device, thereby creating a knotted or spliced end having a diameter greater than the diameter of the groove through which it passes, thereby attaching the shell ends 27,28 to the ends of the core strand 34. The innermost portion of the channel 33a of the core strand attachment device 33 includes a larger average radial diameter to accommodate the knotted or spliced ends of the core strands 34. A larger average radial diameter may preferably increase the average radial diameter by up to 15%, most preferably by 25%, for example by 20%. The ends 27,28 of the elongated sensor housing in the longitudinal direction are then reattached to the sensor housing 3 and thus the sensor device 1 is attached to the core strand 34.

Fig. 10 schematically shows a cable sensor assembly 17, wherein a first end 21 of the cable 2 is fixed to a winch arrangement 18 arranged on a first structure 19. The second end 22 of the cable 2 is fixed to a post, such as a bollard arranged on the second structure 22. The first structure 19 may be a floating structure, such as a boat, and the second structure may be, for example, a docking station 22. The sensor device 1 is inserted into a cable 2 for measuring the tension in the cable 2. In fig. 10, the sensor device 1 comprises a wireless transmission device 16 to send a data signal 24 to a data receiver 15 mounted on the winch device 18.

A winch motor 25 in the winch device 18 is connected to a drum, windlass or the like to wind in or pay out the cable 2. The winch motor 25 may be a motor controlled by a control system 23, which control system 23 is arranged to process the data signal 24 from the sensor device 1. The control system 23 is further arranged to calculate/estimate the tension in the cable 2 based on the received data signals 24 and to determine whether the motor 25 should perform any adjustment by reeling in or paying out the cable 2. The control system 23 preferably also comprises data logging means so that information about the use of a particular cable 2 can be stored for later use. Furthermore, the control system 23 is configured to analyze data regarding previous use of the cable 2 and use this information to determine how much tension a particular cable 2 should be subjected to or when to replace the cable. The control system 23 may also be connected to an alarm or signalling device provided on the winch arrangement 18 and/or it may be connected to an external device, such as a mobile phone, a PC, a control system on the bridge of the ship or the like.

Before deployment of the cable sensor assembly 17, the configuration of the sensor device 1, e.g. the transmission frequency of the data signal, should be set. Deployment of the cable sensor assembly 17 then begins as the sensor device 1 is inserted into the cable 2 at the predetermined insertion point 12. Preferably, the control system 23 is pre-programmed with a set of instructions and is fed with data relating to the cable 2, such as previous use and maximum tension limits. The cable 2 is then paid out from the winch arrangement 18 and the second end 21 is secured to the second structure 22. The winch arrangement 18 adjusts the cable to the desired tension state, which may also be performed by the operator on the basis of visual evaluation, or may be limited by parameters pre-programmed in the control system. As the cable 2 is tightened, the sensor device 1 starts to send signals regarding pressure and/or temperature. These signals are then processed in the winch arrangement 18 to bring the cable 2 to the desired tension. The sensor device 1 will then send a signal at set intervals or if necessary, and the winch device 18 will adjust the tension in the cable 2 accordingly.

Fig. 11 shows the measured values collected during the testing of the sensor device, wherein the cable with the sensor device is placed in a cable tensioning device and subjected to a certain tension in kilograms on the y-axis during the time period represented on the x-axis. The actually applied tension is then measured by the external marking unit in the cable tensioning device indicated by the solid line labeled "original rope" and compared with the tension measured by the sensor device in the cable indicated by the staple line labeled "calculated rope tension". As shown, the cable sensor assembly is subjected to a cyclic test in order to verify that the sensor device reads accurate cable tension values with repeated and predictable results at each cycle. The sensor is inserted into the cable at several different locations within the same cable to verify the ability of the sensor to generate repeated and accurate tension values for the cable, regardless of the axial and rotational position of the sensor on the cable. The figure clearly shows the accuracy of the sensor device for indirectly measuring tension by compression.

In the foregoing description, various aspects of an assembly according to the present invention have been described with reference to illustrative embodiments. For purposes of explanation, specific numbers, systems and configurations were set forth in order to provide a thorough understanding of the devices and their operation. However, this description is not intended to be construed in a limiting sense. Various modifications and alterations of the illustrative embodiments, as well as other embodiments of the apparatus, which are apparent to persons skilled in the art to which the disclosed subject matter pertains are deemed to lie within the scope of the invention.