Method and apparatus for preparing a connection between contact carriers

Abstract

Method for preparing a connection between a first contact carrier (5) of a stationary unit (2) and a second contact carrier (6) of a mobile unit (3), wherein the stationary unit (2) is arranged at a ship landing (4) and wherein the mobile unit (2) is a watercraft, wherein the first contact carrier (5) is displaced relative to the second contact carrier (6) by means of a displacement unit (25) to enable an electrical connection with the second contact carrier (6), wherein at least one transmitter (17) is arranged on the second contact carrier (6), and wherein several receivers (R1, R2, R3, R4) for the wireless reception of the signals (18) of the at least one transmitter (17) are arranged on the first contact carrier (5), wherein the at least one transmitter (17) transmits a pulsed signal (18), and wherein the receivers (R1, R2, R3, R4) receive the pulsed signal (18) at a reception time (t0, t1, t2, t3,t4) receive and forward to an evaluation unit (21) to determine differences in the reception times (t0, t1, t2, t3, t4), wherein the position of the transmitter (17) in a plane of the receivers (R1, R2, R3, R4) is determined from a comparison with a reference value, wherein the position of the first contact carrier (5) is iteratively shifted by means of the displacement unit (25) depending on the differences in the reception times (t0, t1, t2, t3, t4) until the differences in the reception times (t1, t2, t3, t4) fall below a predetermined value, so that the first contact carrier (5) is in a position in which the connection with the second contact carrier (6) can be established, wherein the at least one transmitter (17) and the receivers (R1, R2, R3, R4) are used for near-field positioning, wherein the near-field positioning a wide-field positioning is preceded by the use of additional transmitters (17) and receivers with larger beam and reception angles,wherein the stationary unit (2) is coupled to a tracking system (19) arranged at the ship landing (4), which determines position data of the vessel in order to move the stationary unit (2) to a preliminary position in the horizontal and vertical direction.

Description

[0001] The invention relates to a method for preparing a connection between a first contact carrier of a stationary unit and a second contact carrier of a movable unit according to the features of claim 1 and a corresponding device for carrying out the method according to the features of claim 7.

[0002] Electric charging devices are used to transfer energy between land-based units and mobile ship units. The particular challenge lies in the fact that a ship never assumes exactly the same position when docking. The ship's movements can be caused by its own engine motion against the dock, the waves, fluctuations due to cargo, and tides. Furthermore, the vessel's movements during docking itself, as well as the resulting waves, must be taken into account. Even the presence of another vessel passing by causes relative movements. Overall, the relative movements between the vessel and the land-based unit are unpredictable.

[0003] Wheeled vehicles also do not always have a consistent parking position relative to a loading unit.

[0004] The 10 2017 000 077 B3 relates to an electronic coupling system by means of which a drive unit can be coupled. The coupling system comprises a transmitter unit, a receiver unit, an evaluation unit, and a drive unit. This transmitter unit has a first and second transmitter, which are separated by a transmission distance. The first transmitter sends a first ultrasonic signal, and the second transmitter sends a second ultrasonic signal to a first and second transmission point, respectively. The frequencies differ. The receiver unit has a first and a second receiver, which are separated by a receiver distance. Each of the two receivers can receive both ultrasonic signals, resulting in a total of four signal receptions. Each of the four signal receptions can be assigned a specific time of reception.The difference in reception times of the first and second ultrasound signals at the first receiver, as well as the difference in reception times of the first and second ultrasound signals at the second receiver, can be determined. Based on the difference in signal paths, transmitter distance, and receiver distance, an actual relative position between the transmitting unit and the receiving unit can be determined. A target relative position between the transmitting unit and the receiving unit can be defined, and a control command for a drive unit can be generated by comparing the actual and target relative positions. This command initiates a movement of the drive unit to achieve the target relative position.

[0005] DE 102 37 615 C1 discloses a method and a device for positioning two objects relative to each other, for example, a trailer-side coupling relative to a tractor-side coupling. The device comprises a transmitter that emits a signal beam at a defined beam angle directed at a receiver unit. The receiver unit comprises several receivers arranged side by side. The objects to be positioned or connected can be aligned essentially in perfect alignment by moving them relative to each other such that the same number of receivers on both sides of a central point of the receiver unit detect the signal beam. Furthermore, the two objects can be brought closer together in a controlled manner via distance measurement using the transmitter and the receiver unit.

[0006] A mechanical plug connection between a first contact carrier of a stationary unit and a second contact carrier of a moving unit (vehicle) is subject to the condition that the contact carriers are arranged in a desired position relative to each other in order to be able to establish a plug connection between the contact carriers at all.

[0007] The invention therefore aims to provide a method for preparing a connection between a first contact carrier of a stationary unit and a second contact carrier of a movable unit, which enables the most autonomous positioning possible for the connection. Furthermore, a device for carrying out the method, which is particularly suitable for solving this problem, is to be presented.

[0008] The invention is solved by a method having the features of claim 1. A device for carrying out the method is the subject of claim 7.

[0009] The dependent claims relate to advantageous further developments of the invention.

[0010] The method according to the invention serves to prepare a connection between a first contact carrier of a stationary unit and a second contact carrier of a mobile unit. A mobile unit is a watercraft, while the stationary unit is arranged in a fixed position. An example of a stationary unit is a charging station in a port for charging a watercraft that has moored at a dock.

[0011] A contact carrier within the meaning of the invention is an assembly comprising at least one electrical contact, preferably several, which are to be connected to a further contact carrier, particularly in the sense of a plug-and-socket system. Which of the contact carriers serves as the plug and which as the socket is irrelevant. The basic principle is that, after positioning the movable unit with the second contact carrier (i.e., the watercraft), the stationary unit with the first contact carrier is brought into the desired position to prepare for the electrically conductive connection with the second contact carrier. For this purpose, the first contact carrier has a displacement unit to move the first contact carrier relative to the second contact carrier. By bringing the contact carriers closer together and correctly positioning them, an electrical connection with the second contact carrier is to be made possible.

[0012] Enabling an electrical connection serves primarily for energy transmission and, preferably, also for data transmission. Enabling the electrical connection can be done manually, but preferably automatically. Enabling a manual connection means, for example, that the first contact carrier transports one or more cables with plugs at their ends (contacts) close to the second contact carrier. The second contact carrier, for example, sockets on board a ship, is to be connected to the cables. For this purpose, an employee can pull the cables with the plugs out of the first contact carrier and manually establish the connection with the second contact carrier.In this sense, the contact carrier itself does not directly establish the contact in the inventive method; rather, the inventive method only brings the contact carrier close enough to the second contact carrier that the latter is, for example, only an arm's length away from the connector. If the electrical connection can be established without manual intervention, this is the preferred coupling method for establishing a connection, in particular a connector.

[0013] To prepare for the connection, at least one transmitter is arranged on the second contact carrier, i.e., on the movable unit, e.g., on a ship. In addition, several receivers, positioned relative to each other, are arranged on the first contact carrier for the wireless reception of the signals from the at least one transmitter. The at least one transmitter emits a pulsed signal. The receivers receive the pulsed signal at a specific reception time. An evaluation unit records the respective reception time of the pulsed signal. Depending on the position of the transmitter relative to the receivers, the signal propagation times vary. The differences between the reception times allow conclusions to be drawn as to whether the transmitter is closer to a first or a second receiver. If the reception times coincide, identical signal propagation times result, and thus identical distances between the transmitter and the two or more receivers.The evaluation unit determines these differences in reception times. A comparison with a reference value then follows. This comparison allows the position of the transmitter within a plane of the receiver to be determined. This is a 2D position determination, which does not allow conclusions to be drawn about how far the receiver is perpendicular to the plane of the transmitters, but only allows conclusions to be drawn about whether the transmitter is, for example, centered between the receivers. It is not mandatory for the transmitter to be centered. The transmitter can also be positioned eccentrically. The important thing is that, by comparing it with a reference value, the 2D position of the transmitter relative to the receivers can be determined. From the position of the transmitter, the position of the contacts is inferred. The reference value represents the target state in which the plug and socket are in the correct position.

[0014] In an iterative process, the position of the first contact carrier, i.e., the receiver, is changed by the displacement unit depending on the differences in the reception times until these differences fall within a predefined range or below a predefined limit. The limits are the upper and lower boundaries of a tolerance range around the reference value. In the target position, where the desired values ​​are met, the first contact carrier is positioned in such a way that a plug connection with the second contact carrier can be established.

[0015] To actually establish the connection, it may be necessary to move the first contact carrier closer to the second. During this movement, the position is preferably continuously checked and, if necessary, corrected (i.e., repositioned) according to the aforementioned procedure. In this way, correct positioning is ensured at all times before the connection is established.

[0016] The method according to the invention is preferably based on the use of ultrasound signals. The method is particularly characterized by the fact that communication in the sense of data exchange between a watercraft and the stationary unit is not necessarily required before the connection is established. The stationary unit with the first contact carrier recognizes how the stationary unit should be positioned solely by the approach of the second contact carrier and the ultrasound signal emitted from it.

[0017] The method according to the invention particularly includes the step that, when a second contact carrier approaches relative to the first contact carrier, not only is a preparation of the connection carried out in the sense of positioning, but that a coupling of the contact carriers actually takes place.

[0018] Preferably, the transmitted signals are received by four receivers arranged in a plane such that, in the direction in which two of the receivers are arranged, a time difference measurement is taken between the two spaced-apart receivers and assigned to a specific orientation of a displacement axis of the displacement unit. With a horizontal displacement axis, the two receivers are preferably arranged horizontally at a distance from each other. With an additional vertical displacement axis, two receivers are preferably arranged vertically one above the other. Accordingly, with four receivers and two displacement axes, the receivers are preferably arranged in a rectangular or rhombus shape. The rhombus or cross shape has the advantage that the diagonals run in both the horizontal and vertical directions.This allows for greater distances between the receivers compared to rectangular or square arrangements, resulting in better resolution and signal evaluation.

[0019] The aforementioned receivers, in combination with the transmitter, are used for near-field positioning. Additionally, a long-field positioning system is provided, which precedes the near-field positioning. For long-field positioning, transmitters and receivers with larger transmission and reception angles are used, thus allowing for a larger working range. The long-field positioning can be performed according to the same principle.

[0020] The method according to the invention is supplemented by remote tracking at a ship pier. For this purpose, the stationary unit is coupled with a tracking system arranged at the ship pier, which determines the position of the vessel in order to move the stationary unit to a preliminary position in a horizontal and / or vertical direction.

[0021] For example, receivers can be positioned along the dock to detect an approaching ship at an early stage. The first contact carrier, which may be located on a so-called charging tower, can then be moved to a preliminary position.

[0022] If necessary, sensors can also be positioned along the dock to detect the vessel's vertical position, enabling even more precise positioning. The ideal positioning is achieved when the coupling process requires no major adjustments to the contact carrier's position.

[0023] The entire control of the contact carrier can be achieved through evaluation via a microcontroller or a programmable logic gate (FPGA / Field Programmable Gate Area). FPGAs enable very fast signal processing and flexible circuit modification. Signal evaluation can also be performed via a PLC. Signal processing primarily involves outputting the time differences for the subsequent control of the contact carrier, allowing it to move into the correct position. The individual differences in the received times are used to output a direction vector.

[0024] In a further development of the invention, it is possible to transmit encoded data to at least one of the receivers via the transmitter's signals. The data transmission serves in particular to transmit status data, for example, via pulse-width modulation or frequency modulation. For example, a pulse length of 1 ms can indicate that a watercraft is not yet ready for charging. A pulse length of 3 ms, on the other hand, can signal that the watercraft is ready for charging. Further examples include a 1 ms pulse length indicating that the stationary unit is positioned and the first contact carrier follows, but does not extend to establish the connection. If the signal from the watercraft, i.e., from the second contact carrier, is extended to 3 ms, it signals that the first contact carrier can extend to establish the electrical connection or to couple the contact carriers.

[0025] In this way, an additional interface, e.g. WLAN, for signal exchange in rudimentary systems can be dispensed with.

[0026] In a further development of the method, the second contact carrier is moved towards the first contact carrier after positioning, automatically establishing a plug connection through horizontal and / or vertical coupling between the contact units. The coupling signals can originate from the second contact carrier, i.e., the moving unit, since the energy flow typically occurs from the stationary unit to the moving unit. Horizontal and / or vertical coupling represents different application scenarios. In a so-called ferry charger, where the first contact carrier is moved on land towards the second contact carrier on board a ship, coupling usually occurs horizontally. In a so-called bow charger, mechanical coupling can also occur vertically.Systems that do not require a fixed coupling, but only 2D positioning of the transfer unit and vertical tracking, are also possible. This necessitates horizontal and / or vertical displacement. However, the final coupling is performed manually.

[0027] The method according to the invention therefore also enables purely vertical or purely horizontal tracking (1D positioning). Only two receivers are required for 1D positioning.

[0028] If a fixed coupling is not required, but only 2D positioning of the transfer unit for subsequent manual coupling, four sensors are suitable. Theoretically, an application with three sensors is also possible.

[0029] Additional 3D positioning can be achieved, for example, by measuring the time of flight. For this purpose, a carrier signal, such as from the first contact carrier, can be triggered and received. This can also be a pulsed ultrasound signal. The signal unit on the second contact carrier detects the initial pulse and immediately responds with a reply pulse. The signal travel time between sending the initial pulse and receiving the reply pulse provides information about the distance. This method therefore uses a second transmitter, specifically on the first contact carrier. The evaluation of the signal travel times can be directly converted into control signals for path control at the stationary unit.

[0030] The invention relates not only to a method for preparing a connection, but also to a suitable device for carrying out the method. The device comprises the aforementioned stationary unit with a first contact carrier and the movable unit with a second contact carrier, as well as a displacement unit for moving the first contact carrier relative to the second contact carrier in order to ultimately enable an electrical connection with the second contact carrier. A transmitter is arranged on the second contact carrier, and several receivers, positioned at fixed relative positions, are arranged on the first contact carrier for the wireless reception of the signals from the at least one transmitter.The transmitter sends out pulsed signals, and the receivers forward the received signals to an evaluation unit. There, the differences in the reception times are determined, and the transmitter's position in a plane is calculated by comparing these differences with a reference value. A control unit converts the differences in the reception times into control signals for the displacement unit (i.e., vector data). The displacement unit then iteratively changes the position of the first contact carrier based on the differences in the reception times until these differences reach a predetermined value. This ensures that the first contact carrier is in a position that allows for an electrical connection, particularly a plug connection, with the second contact carrier. For 2D positioning, four receivers are preferably used. The pulsed signals are preferably ultrasonic signals.The movable unit is mounted on a watercraft, particularly a ship such as a ferry. The stationary unit is a land-based unit located at a ship's landing, for example, a quay. An electrical connection between the contact carriers can be automatically established by horizontally and / or vertically moving the first contact carrier.

[0031] The invention is explained in more detail below with reference to exemplary embodiments shown in the purely schematic drawings. These show: Fig. 1 a schematic representation of a device with two contact carriers; Fig. 2 a diagram of the functional components of the device Fig. 1; Fig. 3. A perspective representation of the positions of a transmitter in relation to sensors and Fig. 4. A diagram illustrating the signal propagation times of the transmitter. Fig. 3.

[0032] The Fig. Figure 1 shows a device 1 used in the inventive method for preparing a connection between contact carriers. The device 1 is always based on the interaction between a stationary unit 2 and a movable unit 3. In this embodiment, the movable unit 3 is a watercraft, namely a ship, which docks at a berth 4. A first contact carrier 5 is arranged on the stationary unit 2, i.e., on land. A second contact carrier 6 is located on the movable unit 3, i.e., on board. A connection between the contact carriers 5 and 6 can be established by moving the first contact carrier 5 along path P.

[0033] Even though the method according to the invention always refers to a first contact carrier 5 and a second contact carrier 6, it is clear to a person skilled in the art that there can be a plurality of second contact carriers 6 on different movable units 3. This means that the contact carrier 5 of the stationary unit 2 can be coupled to a plurality of contact carriers 6 on ships. In other ports, further land-based contact carriers 5 are arranged.

[0034] In this embodiment, the second contact carrier 6 has four contacts 7-10, which are to be brought into contact with corresponding, oppositely positioned contacts 11-14 on the first contact carrier 5 to form a plug connection. The first contact carrier 5 is displaced in the X, Y, or Z direction. For this purpose, the first contact carrier 5 is attached to a support 15 in the form of a displaceable arm. The support 15 is connected to a base station 16 in a manner not shown in detail. The base station 16 also includes a control unit and connections for conducting power from the base station 16 via the two contact carriers 5 and 6 to the movable unit 3. The base station 16 with the support 15 forms a displacement unit 25.

[0035] The positioning of the first contact carrier 5 relative to the second contact carrier 6 is achieved using ultrasonic signals. A transmitter 17 is located in the area of ​​the second contact carrier 6 and emits a pulsed signal 18. The pulsed signal 18 is directed towards the first contact unit 5. Four receivers R1-R4 are located in the corner area of ​​the first contact unit 5. These receivers R1-R4 receive the emitted signal 18 and transmit it to an evaluation unit, as described in Fig. Figure 2 illustrates the functionality in more detail. Fig. 3 and Fig. 4 explained.

[0036] Before fine positioning takes place, coarse positioning of the first contact unit 5 is provided. This is done via a tracking system 19, which is arranged at the ship dock 4. Using this tracking system 19, position data of the vessel or the moving unit 3 can be predetermined in order to move the stationary unit 2 to a preliminary position in a horizontal and / or vertical direction.

[0037] After or while the two contact carriers 5, 6 have been moved into the desired 2D position, the distance between them can be determined via a further transmitter 20 on the first contact carrier 5. In a first embodiment, the distance between the contact carriers 5, 6 can be determined by measuring the signal propagation times of the signals reflected from the second contact carrier 6 to the further transmitter 20. Reflected signals are subject to interference, e.g., from the vessel's superstructure, which could potentially distort a reflected signal. Therefore, preferably, according to an alternative embodiment, a response pulse is triggered by an initial pulse from the transmitter 20. Finally, the desired electrical contact is established by moving the first contact carrier 5 in the Z-direction, i.e., towards the first contact carrier 5. Charging can then be initiated via further information exchange.

[0038] The Fig. Figure 2 illustrates schematically that the four receivers R1-R4 each transmit information to an evaluation unit 21. The evaluation unit 21 evaluates the reception times of the signals 18. Since the signal 18 is pulsed, any two receivers R1-R4 at the same distance from the signal source must receive the signal without a time difference. Fig. Figure 1 shows that receivers R1 and R2 in the upper row are spaced the same distance apart as receivers R4 and R3 in the lower row. In the vertical direction, receivers R1 and R4 are positioned vertically above one another, as are receivers R3 and R2. If the transmitter 17 is positioned exactly in the center, the signal propagation times are identical for each pair of receivers R1-R4 that are adjacent in both the horizontal and vertical directions. Therefore, the evaluation unit performs a two-dimensional determination of the position of the signal source, i.e., the transmitter 17. The measurement method is exceptionally robust and can be used reliably even under adverse external conditions. It is cost-effective to implement and does not require a prior data connection between the stationary unit 2 and the mobile unit 3. The sensor 17, which wirelessly transmits signals to receivers R1-R4, can be positioned shortly before entering or exiting the unit.The sensor 17 is activated shortly before approaching dock 4. A control unit 22 is connected upstream of the sensor 17 for this purpose.

[0039] The evaluation unit 21 delivers the results of the evaluations to a controller 23 of the base station 16. This controller 23 serves to output the necessary control signals for an axis controller 24 so that the carrier 15 is moved in the desired spatial directions or so that the first contact carrier 5 assumes the desired position.

[0040] Furthermore, the control unit 22 of the movable unit 3 is capable of modifying the signal length or waveform of the ultrasonic signals from the sensor 17. In particular, the signal length can be linked to information that prompts the control unit 23 of the first contact carrier 5 to extend the land-side first contact carrier 5 and establish the coupling, or to leave it in a waiting position. The signal length can also be used to transmit whether or not the energy flow should be enabled. The control unit 22 can also interrupt the energy flow in this way by transmitting a corresponding signal from the transmitter 17 to the receivers R1–R4.

[0041] The Fig. Figure 3 shows four receivers R1-R4 arranged in a plane. The drawn coordinate system spans an X, Y plane. This X, Y plane lies in the same plane as the receivers R1-R4.

[0042] Positions A, B, C, and D illustrate the positions of a transmitter 17. Positions A, B, and C are shifted by the same amount in the negative Z-direction. The lines oriented in the X-direction all lie in the X, Y-plane. Therefore, from the viewer's perspective, positions A, B, and C are behind the plane of sensors R1-R4, and position D is in front of the plane of receivers R1-R4, i.e., in the positive Z-direction.

[0043] In position A, a transmitter 17 emits a pulsed signal. Due to the spatial distance, this signal is first received by receiver R1, then by receiver R4, followed by receiver R2, and finally by the furthest receiver R3. Fig. Figure 4 shows, in the first column labeled A, the reception times t2 - t4 of the individual receivers R1 - R4. The signal from transmitter 17 is transmitted at an unknown time. For illustration, the time at which one of the receivers R1 - R4 first receives the signal is designated t0. The t0 line is shown as a dashed line. In the embodiment with the transmitter in position A, receiver R1 is the first to receive the square wave signal at reception time t0. The signal length tS is, for example, 1 ms. In this case, the signal is a square wave. Transmitter R2 receives the first signal with a time delay (reception time t2). Accordingly, the other receivers R3 and R4 receive the signal at reception times t3 and t4, respectively.

[0044] Since the signal is pulsed, the square wave signal is emitted at specific intervals. The signal spacing is denoted as tF. If no signal is received within the period in which the subsequent signal should be received, the distance between the first and second contact carriers 5, 6 is still too large. According to the invention, in this embodiment, only the period of 0.25 x tF is considered. Within this interval, fine-tuning takes place, thus achieving the desired fine positioning of the contact carriers. Wide-field sensors with larger beam angles (not shown) can perform a coarser pre-positioning in the same way.

[0045] The receivers R1, R2, R3, and R4, which are fixed in position relative to each other, receive the signal at different times in example position A. The differences in these reception times also allow us to determine in which direction receivers R1-R4 must be moved so that transmitter 17, or the first contact carrier 5, is in the correct relative position. For example, the difference between reception times t1 and t2 provides information about the necessary movement in the X-direction. Similarly, this information is obtained from the difference between reception times t3 and t4 between receivers R3 and R4. These receivers are also spaced apart in the X-direction. The reception times of the vertically stacked receivers R1 and R4, and R2 and R3, indicate whether a movement in the Y-direction is required. In this case, the Y-direction corresponds to the vertical direction.

[0046] Based on the signal propagation times, position A of transmitter 17 is located in the negative X-direction. It's important to note that to compensate, the position of receivers R1-R4 is not shifted, but rather the position of the receivers themselves. Therefore, the receivers must be shifted in the negative X-direction. Simultaneously, receivers R1-R4 would need to be shifted in the +Y-direction. It is assumed that transmitter A is located at the origin of the coordinate system. Of course, any other point in space projected onto the XY plane can be used. For this purpose, the signals are compared to a predefined reference value. This reference value does not necessarily mean that all receivers R1-R4 receive the signal simultaneously. For calibration or fine-tuning, it may even be necessary to account for certain deviations, which are stored as a suitable reference value.This means that different reception times can be specifically specified as target values.

[0047] In example position B, receiver R1 is closest to sender 17. Receivers R2, R4, and R3 follow. The time period t2 - t3 can be calculated by examining the difference between the second receiver R2 and the third receiver R3. Fig. Figure 4 is shown. Based on this information, it follows that receivers R1 - R4 must be moved in the +Y direction. From the other differences, it can be deduced that receivers R1 - R4 must be moved in the negative X direction.

[0048] For example position C, the relative signal propagation times result in a necessary relocation of receivers R1 - R4 in the +X direction and +Y direction.

[0049] The position D of transmitter 17 means that receiver R4 receives the transmitted signal first, and the other receivers R1, R2, and R3 receive it later. Receivers R1–R4 would need to be moved in the -X and -Y directions until transmitter 17 is located at the origin of the coordinate system.

[0050] It has not yet been taken into account that the example positions A, B, C, and D are not located in the X and Y planes. The method according to the invention focuses solely on preparing the connection between the first and second contact carriers 5 and 6. Using optional additional sensors, in particular a time-of-flight measurement in the Z direction, the distance of the transmitter 17 in the Z direction from the receivers R1-R4 can be reliably determined. This distance can be reduced manually or automatically.

[0051] In principle, it is also possible to always keep the first contact carrier 5 in a starting position in which a collision with the second contact carrier 6 is completely impossible. This makes it possible to align the contacts to be coupled solely through fine positioning and then to couple them with a desired insertion force and hold them in the coupled position. It is possible to provide locking mechanisms during energy transfer to prevent unwanted decoupling.

[0052] The method according to the invention or the device used is of course also suitable for guiding the two contact carriers 5, 6 and not only for preparing the connections in which the contact carriers 5, 6 are still arranged at a distance from each other. Reference symbol: 1 Device 2 stationary units 3 movable units 4 ship berths 5 first contact carrier 6 second contact carrier 7 Contact at 6 8 contacts at 6 9 contacts at 6 10 contacts at 6 11 contacts at 5 12 contacts at 5 13 contacts at 5 14 contacts at 5 15 carriers 16 base stations 17 channels 18 Signal 19 Location system 20 channels 21 evaluation unit 22 Control of 17 23 Control of 16 24-axis control 25 relocation units A sample position of 17 B Example position of 17 Example position C of 17 D Example position of 17 P path R1 receiver of 5 R2 receiver of 5 R3 receiver of 5 R4 receiver of 5 t time t0 reception time t1 reception time t2 reception time t3 reception time t4 reception time tF signal distance tS signal length X coordinate axis Y coordinate axis Z coordinate axis

Claims

[1] Method for preparing a connection between a first contact carrier (5) of a stationary unit (2) and a second contact carrier (6) of a movable unit (3), wherein the stationary unit (2) is arranged at a ship's pier (4) and wherein the movable unit (2) is a watercraft, wherein the first contact carrier (5) is displaced relative to the second contact carrier (6) by means of a displacement unit (25) in order to enable an electrical connection with the second contact carrier (6), wherein at least one transmitter (17) is arranged on the second contact carrier (6), and wherein a plurality of receivers (R1, R2, R3, R4) positioned stationary relative to one another are arranged on the first contact carrier (5) for wirelessly receiving the signals (18) of the at least one transmitter (17), wherein the at least one transmitter (17) transmits a pulsed signal (18), wherein the receivers (R1, R2, R3, R4) receive the pulsed signals (18) at a reception time (t0, t1, t2, t3,t4) and forward them to an evaluation unit (21) in order to determine differences in the reception times (t0, t1, t2, t3, t4), wherein the position of the transmitter (17) in a plane of the receivers (R1, R2, R3, R4) is determined from the comparison with a reference value, wherein the position of the first contact carrier (5) is iteratively displaced by means of the displacement unit (25) as a function of the differences in the reception times (t0, t1, t2, t3, t4) until the differences in the reception times (t1, t2, t3, t4) fall below a predetermined value, so that the first contact carrier (5) is in a position in which the connection to the second contact carrier (6) can be established, wherein the at least one transmitter (17) and the receivers (R1, R2, R3, R4) are used for near-field positioning, wherein the Near-field positioning is preceded by a wide-field positioning in which additional transmitters (17) and receivers with larger radiation and reception angles are used,wherein the stationary unit (2) is coupled to a positioning system (19) arranged on the pier (4), which determines position data of the watercraft in order to displace the stationary unit (2) in the horizontal and vertical directions into a pre-position. [2] Method according to claim 1, characterized by that the at least one transmitter (17) emits an ultrasonic signal. [3] Method according to claim 1 or 2, characterized by that the transmitted signals (18) are received by four receivers (R1, R2, R3, R4) which are arranged in a plane such that, in the direction in which two of the receivers (R1, R2, R3, R4) are arranged, a difference time measurement between the two receivers (R1, R2, R3, R4) is directly assigned to an orientation of a displacement axis of the displacement unit (25). [4] Method according to one of claims 1 to 3, characterized bythat coded data are transmitted to at least one of the receivers (R1, R2, R3, R4) via the signals of the transmitter (17). [5] Method according to one of claims 1 to 4, characterized by that the second contact carrier (6) is moved in the direction of the first contact carrier (5) after positioning in order to automatically establish a plug connection by horizontal and / or vertical coupling between the contact units. [6] Method according to one of claims 1 to 5, characterized by in that the first contact carrier (5) has a plurality of plugs which are positioned at a predetermined distance from corresponding sockets of the second contact carrier (6), the connection between plugs and sockets being established manually and the first contact carrier (5) being guided in the vertical direction relative to the second contact carrier (6). [7] Device for carrying out the method according to one of the features 1 to 6, having the following features: a) A stationary unit (2) has a first contact carrier (5) and a movable unit (3) has a second contact carrier (6), wherein the movable unit (3) is arranged on a watercraft and the stationary unit (2) is a land unit arranged on a jetty (4); b) The stationary unit comprises a displacement unit (25) for displacing the first contact carrier (5) relative to the second contact carrier (6) to enable an electrical connection with the second contact carrier (6), wherein the contact carriers (5, 6) are designed to establish an electrical connection between the contact carriers (5, 6) by horizontal and vertical coupling; c) At least one transmitter (17) is arranged on the second contact carrier (6) and a plurality of receivers (R1, R2, R3, R4) positioned stationary relative to one another for wireless reception of the signals (18) of the at least one transmitter (17) are arranged on the first contact carrier (5); d) The at least one transmitter (17) is designed to transmit pulsed signals (18) and the receivers (R1, R2, R3) are designed to receive the pulsed signals (18) at a reception time (t0, t1, t2, t3, t4) and to forward them to an evaluation unit (21); e) The evaluation unit (21) is designed to determine differences in the reception times (t0, t1, t2, t3, t4) and to determine the position of the transmitter (17) in a plane of the receivers (R1, R2, R3, R4) from the comparison with a reference value; f) A control unit (22, 23) is designed to convert the differences in the reception times (t0, t1, t2, t3, t4) into control signals for the displacement unit (25), so that the position of the first contact carrier (5) is iteratively displaced by means of the displacement unit (25) as a function of the differences in the reception times (t0, t1, t2, t3, t4) until the differences in the reception times (t0, t1, t2, t3, t4) are within a predetermined tolerance range around the reference value, so that the first contact carrier (5) is in a position in which the connection to the second contact carrier (6) can be established; g) The stationary unit (2) is coupled to a positioning system (19) arranged on the pier (4), which determines position data of the watercraft in order to move the stationary unit (2) in the horizontal and / or vertical direction into a pre-position. [8] Device according to claim 7, characterized bythat the pulsed signals (18) are ultrasonic signals. [9] Device according to claim 7 or 8, characterized by that the first contact carrier (5) has four receivers (R1, R2, R3, R4). [10] Device according to one of claims 7 to 9, characterized by that the pulsed signals (18) contain coded data

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