Method and system for controlling the winding or unwinding of a rope section onto or from a rotating drum

Description

[0001] The present invention relates to a method and a system for controlling the winding or unwinding of a rope section onto or from a rotating drum.

[0002] It is known in the art to use a rotating drum to wind a rope onto or off it. Such rotating drums usually have a circular cylindrical winding surface onto which the rope can be wound by rotating the drum, allowing it to be stored in a space-saving manner and then unwound again when required. Unwinding occurs by rotating the rotating drum in the opposite direction. Such rotating drums are used, for example, to pay out (unwind) and retrieve (wind up) a towing rope to which a wind-engaging element designed for deployment is attached. In such applications, the retrieval and retrieval of the towing rope must be carried out with the greatest possible precision. This is particularly true when retrieving the towing rope in preparation for landing of the wind-engaging element, where the wind-engaging element is docked to a landing gear by retrieving it.

[0003] In the prior art, it is common practice to determine the length of a rope section wound onto or unwound from the rotating drum using the angle of rotation of the rotating drum during winding. Since the rope is usually wound in a circle on the rotating drum, the length L of the wound or unwound rope section can be determined using the formula L = α 2 πr 360 be determined, whereby α the respective angle of rotation, and r denotes the "radius of the winding pattern," i.e., the distance between the rotation axis of the rotating drum and the point where the rope transitions into the winding. However, it has been shown that this method of determining the unwound or wound rope section often does not provide the desired accuracy.

[0004] Furthermore, EP 0 103 162 A2 discloses a measuring and control device for loads suspended from ropes, in which the rope is guided vertically downwards through a tube and is freely movable relative to the tube, wherein the tube is equipped with sensors for detecting a rope marking.

[0005] Against this background, the object of the present invention is to provide a method and a system for controlling the winding and unwinding of a cable section onto or from a rotating drum, which provides greater accuracy. This object is achieved with the features of the independent claims. Preferred embodiments are described in the subclaims. According to the invention, the method comprises the following steps: a. Providing a rope that is at least partially wound onto a rotating drum, the rope being guided from the rotating drum along a defined path to a retrieval point, a tensile force acting on the rope beyond the retrieval point; b. Unwinding or winding the rope while rotating the rotating drum so that a defined rope section is moved along the defined path; c. Determining the length of the defined rope section in the region of the defined path; d. Determining an angular difference corresponding to the rotation performed in step b.; e. Controlling the rotating drum for further winding or unwinding, taking into account the variables determined in steps c. and d.

[0006] First, some of the terms used in the context of the invention will be explained. In the context of the invention, the fetching point is a point at which the rope's mobility is restricted to the extent that, when a tensile force acts beyond the fetching point, the rope runs along the defined path between the rope exit position of the rotating drum (i.e. a point at which the rope leaves the rotating drum) and the fetching point, i.e. is tensioned between the drum and the fetching point. This guides the rope along the defined path, even when a tensile force acts on the rope whose direction encloses an angle with the defined path. The fetching point can, for example, be a deflection point, which is formed, for example, by a deflection pulley. The defined path usually runs in a straight line from the rope exit position of the rotating drum to the fetching point.It is also possible for the rope to be redirected along the defined path, for example by rollers.

[0007] The invention is based on the realization that the simple assignment of the angle of rotation to an unwound or wound section of rope length, as known from the prior art, often leads to erroneous results. This is due, among other things, to the fact that the rope can stretch plastically and / or elastically during use and is therefore subject to a change in length. Plastic stretching leads to a permanent lengthening of the rope. This occurs, for example, in synthetic fiber ropes and particularly at the beginning of their service life. In addition, a load-dependent elastic change in length can occur, in which the rope lengthens when tensile force is applied and shortens again in a reversible manner when the tensile force decreases.

[0008] The changes in length mentioned above can lead to a situation where a rotation angle of the rotating drum cannot be clearly assigned to a section of unwound or wound-up traction rope.

[0009] Within the scope of the invention, it was further recognized that the effective drum circumference of a winding pattern created by winding the rope onto the rotating drum can depend on the tensile force acting during winding. The effective drum circumference refers to the length of a rope section wound up or unwound during a 360° rotation of the rotating drum. If the rope is elastically stretched due to strong tensile forces during winding, this can lead to a reduction in the effective drum circumference, particularly in the case of multi-layer winding, since the rope diameter decreases due to the stretch. Alternatively or additionally, the effective drum circumference can also be influenced by the type of winding or, for example, by winding errors.

[0010] Against this background, the present invention proposes guiding a rope from the rotating drum along a defined path to a retrieval point, so that the rope runs along the defined path between the rotating drum and the retrieval point when unwinding or winding. This makes it easy to determine the length of a defined section of rope wound up or unwound by the rotation of the rotating drum in the area of ​​the defined path, as well as the associated angle difference. The invention therefore makes it possible to carry out a measurement while the rotating drum is in use, which measurement can be directly taken into account in the further control of the rotating drum in order to improve the accuracy of the control. During use when unwinding or windingChanges in the length of the rope during winding (in particular those dependent on the tensile force) can be taken into account directly by the method according to the invention and calibration can be carried out during use in order to control the rotating drum with increased accuracy.

[0011] In a preferred embodiment, the rope has a first marking and a second marking spaced from the first, wherein the defined path has a sensor position. Preferably, in step b. the rope is wound or unwound such that the first marking passes the sensor position and the second marking passes or at least reaches the sensor position, wherein the first marking and the second marking are detected when they pass or reach the sensor position. Preferably, the length in step c. is determined by the distance between the markings, wherein the angular difference between the angular position of the rotating drum when the first marking is detected and the angular position of the rotating drum when the second marking is detected is determined. In this embodiment, the invention therefore proposes using a rope with two markings spaced from one another. When unwinding or windingBy winding up the rope by rotating the rotating drum, the markings can be guided past the sensor position in a defined manner, namely along the defined path, and detected there. At the same time, the angular difference made by the rotating drum between the detection of the first marking and the detection of the second marking can be determined. This angular difference can then be related to the distance between the two markings and thus taken into account in the further control. Since the distance between the markings is known, calibration can be carried out using the method according to the invention, so that a rope section of the desired length can be wound up or unwound precisely by rotating the rotating drum accordingly.

[0012] Since a tensile force acts on the rope during unwinding or winding, the rope can be subject to tensile force-dependent elastic stretching, as explained above, which influences the distance between the markings. This can lead to an error in the calibration explained above if the length of the defined rope section is determined by the distance between the markings. It can therefore be provided that the distance between the markings is corrected taking into account rope stretching. For example, the distance between the markings can be remeasured, for example in a state in which no tensile force is acting on the rope. Plastic stretching of the rope in the area between the markings can be determined in this way. Elastic stretching of the rope can be estimated, for example, based on the strength of the tensile force acting on the rope during the detection of the markings.For this purpose, a force sensor can be provided to measure the tensile force acting on the rope, whereby an elastic rope elongation can be estimated from the tensile force.

[0013] In order to avoid the above-mentioned error, in an alternative embodiment according to the invention it can be provided that the cable has a marking, wherein the defined path has a first sensor position and a second sensor position spaced from the first, wherein in step b. the cable is unwound or wound up such that the marking passes the first sensor position and passes or at least reaches the second sensor position. The marking is preferably detected when passing or reaching the sensor positions, wherein the length is determined in step c. by the distance between the sensor positions (measured along the defined path) and wherein the angular difference between the angular position of the rotating drum when the marking is detected at the first sensor position and the angular position of the rotating drum when the marking is detected at the second sensor position is determined.In this embodiment, two sensor positions are provided, although the rope does not necessarily need to have two markings; a single marking is sufficient to carry out the method according to the invention. The aforementioned measurement error can thus be avoided. However, it is more cost-effective to use only one sensor position (and two markings), as this eliminates the need for a single sensor.

[0014] In an advantageous embodiment, the tensile force is exerted by a wind-engaging element designed for deployment and attached to the rope. Preferably, the wind-engaging element can be docked to a docking adapter from the deployment position while the rope is being retrieved, with the detection of the marking(s) preferably being carried out while the rope is being retrieved, and with the wind-engaging element being docked taking into account the variables determined in steps c. and d. A corresponding wind-engaging element designed for docking to a docking adapter is known, for example, from WO 2005 / 100150 A1. The method according to the invention enables particularly precise retrieval of the traction rope, so that the rope can be retrieved in a simple manner exactly as far as is necessary to dock the wind-engaging element.This can significantly speed up the docking process and also reduce or avoid the risk of a collision with the docking adapter.

[0015] The present invention further relates to a system for controlling the winding or unwinding of a cable section onto or from a rotating drum, comprising a rotating drum with a system for winding or unwinding a cable section onto or from the rotating drum.a rope that can be unwound from the rotating drum and with an angle sensor for detecting a rotation angle of the rotating drum and for emitting an angle signal, characterized in that the system further comprises a fetching point, a length measuring device and a control unit, wherein the rope is guided from the rotating drum along a defined path to the fetching point, wherein the length measuring device is designed to determine the length of a defined rope section running along the defined path by rotation of the rotating drum and to emit a length signal, wherein the control unit is designed to receive the angle signal and the length signal and to control the rotating drum taking into account the length signal and the angle signal.

[0016] In one embodiment, the length measuring device comprises a sensor, wherein the rope has a first marking and a second marking spaced from the first, wherein the sensor is arranged to detect the markings in the region of the defined path and is designed to emit a first length signal upon detection of the first marking and to emit a second length signal upon detection of the second marking, wherein the control unit is designed to determine an angle difference based on the angle signal and the length signals.

[0017] In an alternative embodiment, the length measuring device comprises a first sensor and a second sensor spaced apart from the first, wherein the rope has a marking, wherein the first sensor is arranged to detect the marking in the region of the defined path and is designed to emit a first length signal, wherein the second sensor is arranged to detect the marking in the region of the defined path and is designed to emit a second length signal, wherein the control unit is designed to determine an angular difference based on the angle signal and the length signals.

[0018] The system according to the invention can be further developed by further features that have already been described in connection with the method according to the invention. In particular, the system can be configured to carry out the method.

[0019] The sensor can detect the markings, for example, optically, electromagnetically, or mechanically. In an advantageous embodiment, the at least one marking is formed by a metallic element integrated into the rope, with the sensor being designed as an inductive sensor.

[0020] The system may comprise a wind-engaging element connected to the cable and configured for deployment. Preferably, the wind-engaging element can be docked to a docking adapter while the cable is being retrieved.

[0021] The distance between the first marking and the second marking can be, for example, between 1 m and 30 m, preferably between 2 m and 20 m, more preferably between 5 m and 15 m. It has been shown that distances in this range are particularly advantageous when using the system to recover (i.e., land and dock) a wind-exposed element, as sufficient accuracy can be achieved in controlling the rotating drum.

[0022] In case the system has two sensors, these can have a distance (measured along the defined path) between 0.1 m and 5 m, preferably between 0.2 m and 3 m, more preferably between 1 m and 2 m.

[0023] In addition to improving the control accuracy, the marking(s) can be used according to the invention as indicators of how far the rope has already been reeled in. For this purpose, it can be provided that the marking(s) are arranged at a defined position on the rope. For example, the markings can be arranged near the end of the rope furthest from the rotating drum in order to provide an indication when the rope is being reeled in that the rope has been almost completely reeled in. When used with a wind engagement element, the marking(s) can be at a defined distance from an attachment point to which the rope is connected to the wind engagement element. In a preferred embodiment, it is provided that the marking(s)(in the case of two markers) the marker located away from the rotating drum has a distance from an attachment point to which the rope is connected to the wind-engaging element of between 5 m and 40 m, preferably between 10 m and 30 m, and more preferably between 15 m and 25 m. The closer the markers are to the attachment point, the more accurately a subsequent docking process with the docking adapter can be carried out after the markers have been detected.

[0024] Furthermore, it can be provided that the distance between the marking located at a distance from the rotating drum and the sensor position is at least 2 m, preferably at least 4 m, more preferably at least 5 m when the wind attack element is docked to the docking adapter. The distance is measured along the cable. This embodiment ensures that when the wind attack element is retrieved, the distant marking is detected by the sensor well before the docking position is reached. In this embodiment, the wind attack element can be retrieved at high speed and braked after the sensor has detected the distant marking, whereby the above-mentioned minimum distances enable the wind attack element to be safely braked before reaching the docking adapter.

[0025] Advantageous embodiments of the invention are explained below by way of example with reference to the accompanying drawings. They show: Figure 1: a schematic representation of an embodiment of the invention; Figure 2: an alternative embodiment of the present invention in a schematic representation.

[0026] Figure 1shows a first embodiment of the system according to the invention for controlling a rotating drum in a schematic view. The system comprises a rotating drum designed as a cable winch 13. A synthetic fiber cable 14 is partially wound onto the cable winch 13. The cable winch 13 has a drive 31, which drives the cable winch 13 to perform a winding movement. The drive is connected to a control unit 30 so that the control unit 30 can control the cable winch 13 to wind or unwind the cable 14. The system also has an angle sensor 32, which is connected to the cable winch 13. The angle sensor detects the angular position of the cable winch and is designed to output a corresponding angle signal to the control unit 30.

[0027] From a cable exit position 15 of the cable winch 13 to a deflection pulley 16, the cable is guided along a defined path 17. The deflection pulley 16 forms a hauling point within the meaning of the present invention. A wind-engaging element 18 is attached to the end of the cable 14 opposite the traction cable winch 13. The wind-engaging element 18 is subject to wind, so that it exerts a tensile force on the cable 14. The wind-engaging element 18 has a control pod 23, from which the cable 14 fans out into a plurality of control lines connected to the wind-engaging element 18. The control pod 23 is designed in a generally known manner to shorten or lengthen the control lines for controlling the wind-engaging element 18. The control pod 23 receives control commands from the control unit 30 via a wireless connection.

[0028] The cable 14 is provided with a first marking 20a and a second marking 20b spaced apart from the first marking. The distance between the markings 20a, 20b is approximately 19 m. A sensor 22 is arranged in the area of ​​the defined path 17 and is connected to the control unit. By appropriately unwinding or winding the cable 14, the markings 20a, 20b can be guided past the sensor 22. The sensor 22 is designed to detect the passing of the markings 20a, 20b and, upon detection of the markings, to transmit a length signal to the control unit. For this purpose, the markings 20a, 20b are formed by metallic elements integrated into the synthetic fiber cable 14, with the sensor being designed as an inductive sensor.

[0029] Based on the Figure 1The following explains the functioning of the system when retrieving and docking the wind-exposed element 18 using the situation shown. To retrieve the wind-exposed element, the cable 14 is wound up by appropriately controlling the drive 31. The marking 20a approaches the sensor 22. When the marking 20a passes the sensor, the sensor 22 sends a first length signal to the control unit 30, whereupon the control unit 30 queries the current angular position of the cable winch 13 via the angle sensor 32. When, after further retrieval of the cable 14, the second marking 20b passes the sensor, the sensor sends a second length signal to the control unit 30, whereupon the control unit 30 again queries the current angular position of the cable winch 13 via the angle sensor 32. Based on the two queried angular positions, the control unit 30 then calculates an angular difference.This angular difference is then related to the known distance between the markings 20a, 20b to determine an "effective drum circumference." As the rope 14 is further retrieved to dock the wind-engaging element 18 to a . Figure 1 The determined "effective drum circumference" is taken into account by the docking adapter (not shown). With the aid of the system according to the invention, docking can thus be carried out with great precision.

[0030] The retrieval can be carried out at high speed until the marker 20b is detected by sensor 22. When the marker 20b is detected by sensor 22, the wind-engaging element is still approximately 5 m from its docking position. This distance is sufficient to "decelerate" the wind-engaging element and then safely dock it, taking into account the determined "effective drum circumference."

[0031] Figure 2shows a schematic view of an alternative embodiment of the present invention. The second embodiment differs from the first embodiment in that the rope 14 has only one marking 20. Furthermore, in contrast to the first embodiment, two spaced-apart sensors 22a, 22b are arranged along the defined path 17. The sensors 22a, 22b are designed to detect the marking 20 and to output a length signal to the control unit 30. In contrast to the first embodiment, the angular difference is determined by querying the angular position upon detection of the marking 20 by the first sensor 22a and subsequently querying the angular position upon detection of the marking 20 by the second angle sensor 22b. To determine the effective drum circumference, the angular difference is then related to the distance between the sensors 22a, 22b along the defined path 17.Otherwise, the functionality of this embodiment corresponds to that of the . Figure 1 .

Claims

1. Method for controlling the winding / unwinding of a rope portion onto / from a rotary drum (13), said method comprising the following steps: a. making available a rope (14) which is at least partially wound onto a rotary drum (13), wherein the rope (14) is guided from the rotary drum (13) along a defined path (17) as far as a hauling point (16), which is formed by a deflection roller, for example, wherein a traction force acts on the rope (14) beyond the hauling point (16) ; b. unwinding or winding the rope (14) by executing a rotation of the rotary drum (13), such that a defined rope portion is moved along the defined path (17); c. determining the length of the defined rope portion in the region of the defined path (17); d. determining an angle difference corresponding to the rotation executed in step b.; e. controlling the rotary drum (14) for further winding / unwinding taking into account the parameters determined in steps c. and d.

2. Method according to Claim 1, in which the rope (14) has a first marking (20a) and a second marking (20b) spaced apart from the first one, wherein the defined path (17) has a sensor position, and wherein in step b. the rope (14) is unwound or wound up such that the first marking (20a) passes the sensor position and the second marking (20b) passes or at least reaches the sensor position, wherein the first marking (20a) and the second marking (20b) are detected as they pass or reach the sensor position, wherein the length in step c. is determined by the known spacing of the markings (20a, 20b), and wherein the angle difference between the angle position of the rotary drum (13) upon detection of the first marking (20a) and the angle position of the rotary drum (13) upon detection of the second marking (20b) is determined.

3. Method according to Claim 2, in which the known spacing between the markings (20a, 20b) is corrected taking into account a rope elongation.

4. Method according to Claim 1, in which the rope (14) has one marking (20), wherein the defined path (17) has a first sensor position and a second sensor position spaced apart from the first one, wherein in step b. the rope (14) is unwound or wound up such that the marking (20) passes the first sensor position and passes or at least reaches the second sensor position, wherein the marking (20) is detected as it passes or reaches the sensor positions, wherein the length in step c. is determined by the spacing of the sensor positions, and wherein the angle difference between the angle position of the rotary drum (13) upon detection of the marking (20) at the first sensor position and the angle position of the rotary drum (13) upon detection of the marking at the second sensor position is determined.

5. Method according to one of Claims 1 to 4, in which the traction force is exerted by a free-flying wind-attacked element (18) secured to the rope (14).

6. Method according to Claim 5, in which the wind-attacked element (18), from the free-flying state, can be docked to a docking adapter when the rope (14) is hauled in, wherein the detection of the marking (20) or of the markings (20a, 20b) is preferably carried out during the hauling-in of the rope (14), and wherein the wind-attacked element (18) is docked taking into account the parameters determined in steps c. and d.

7. System for controlling the winding / unwinding of a rope portion onto / from a rotary drum (13), said system comprising a rotary drum (13) with a rope (14) that can be wound onto / unwound from the rotary drum (13), and with an angle sensor (32) for detecting a rotation angle of the rotary drum (13) and for outputting an angle signal, characterized in that the system moreover has a hauling point (16), which is formed by a deflection roller, for example, a length-measuring device and a control unit (30), wherein the rope (14) is guided from the rotary drum (13) along a defined path (17) to the hauling point (16), wherein the length-measuring device is configured to determine the length of a defined rope portion extending along the defined path (17) upon rotation of the rotary drum (13) and to output a length signal, wherein the control unit (30) is configured to receive the angle signal and the length signal and also to control the rotary drum (13) taking into account the length signal and the angle signal.

8. System according to Claim 7, in which the length-measuring device has a sensor (22), wherein the rope (14) has a first marking (20a) and a second marking (20b) spaced apart from the first one, wherein the sensor (22) for detecting the markings (20a, 20b) is arranged in the region of the defined path (17) and is configured to output a first length signal upon detection of the first marking and to output a second length signal upon detection of the second marking (20a, 20b), wherein the control unit (30) is configured to determine an angle difference on the basis of the angle signal and the length signals.

9. System according to Claim 7, in which the length-measuring device has a first sensor (22a) and a second sensor (22b) spaced apart from the first one, wherein the rope (14) has one marking (20), wherein the first sensor (22a) for detecting the marking (20) is arranged in the region of the defined path (17) and is configured to output a first length signal, wherein the second sensor (22b) for detecting the marking is arranged in the region of the defined path (17) and is configured to output a second length signal, wherein the control unit (30) is configured to determine an angle difference on the basis of the angle signal and the length signals.

10. System according to one of Claims 7 to 9, which moreover has a wind-attacked element (18) connected to the rope (14) and designed to fly freely, wherein the wind-attacked element (18), preferably from the free-flying state, can be docked to a docking adapter when the rope (14) is hauled in.

11. System according to Claim 10, in which the spacing between the first marking (20a) and the second marking (20b) is between 1 m and 30 m, preferably between 2 m and 20 m, more preferably between 5 m and 15 m, or in which the spacing between the sensors (22a, 22b) is between 0.1 m and 5 m, preferably between 0.2 m and 3 m, more preferably between 1 m and 2 m.

12. System according to Claim 10 or 11, in which the marking (20), or the marking (20b) lying remote from the rotary drum (13), is at a spacing from a securing point at which the rope (14) is connected to the wind-attacked element (18), which spacing is between 5 m and 40 m, preferably between 10 m and 30 m, more preferably between 15 m and 25 m.

13. System according to one of Claims 10 to 12, in which the spacing between the marking (20b) lying remote from the rotary drum (13) and the sensor (22), or the spacing between the sensor position (22a) lying remote from the rotary drum (13) and the marking (20), is at least 2 m, preferably at least 4 m, more preferably at least 5 m, when the wind-attacked element (18) is docked to the docking adapter.

14. Use of the system according to one of Claims 7 to 13 for docking a wind-attacked element (18) to a docking adapter.