Method, mobile body, system, and computer program for determining and / or improving a mobile body's position estimate

Abstract

A method (400) for determining and / or improving a position estimate of a moving body (110) comprising a step (a) (410) comprising determining at least three distances (160) of the moving body (110) from at least three signal generators (120), each distance being a distance between the moving body (110) and one of the at least three signal generators, where each of the at least three signal generators has a predefined position with respect to a moving coordinate system (130), the moving coordinate system being a coordinate system in which the position of a non-moving object may change due to a movement of a coordinate origin. The method (400) further comprises a step (b) (420) comprising determining and / or improving a position estimate of the moving body (110) by using the at least three determined distances (160) of the moving body (110) from the at least three signal generators (120) and the predefined positions of the at least three signal generators with respect to the moving coordinate system.

Description

[Technical Field]

[0001] Embodiments according to the invention relate to methods, mobile bodies, systems, and computer programs for determining and / or improving a position estimate of a mobile body. Further embodiments relate to a positioning system with centimeter-accurate distance measurements using radio waves over distributed radio beacons. [Background technology]

[0002] The prior art knows several methods for navigating a moving object, which allow the position of the moving object to be determined. For example, using GPS, the position can be determined to within a few meters by determining the distance of the moving object from multiple satellites. However, a problem with such methods is that they often lack the precision for precise navigation tasks. This problem becomes even more complicated when the moving object is to be navigated relative to a moving object. For example, when inspecting a moving ship or a floating oil or gas platform with an autonomous drone, very precise knowledge of the drone's position relative to the object, i.e., the ship or platform, is required. Uncertainties in the position estimation of both the object and the moving object in previous approaches mean that the movement trajectory of the inspection target along the moving object cannot be realized with sufficient precision for accurate inspection. Therefore, an improved concept is needed for determining and / or improving the position estimation of a moving object relative to a moving object. Summary of the Invention [Problem to be solved by the invention]

[0003] It is an object of the present invention to provide a concept for achieving accurate position estimation of a moving object with respect to a moving coordinate system. [Means for solving the problem]

[0004] This object is solved by the independent claims. Inventive further developments are defined in the dependent claims.

[0005] An embodiment in accordance with the present invention includes a method for determining and / or improving a position estimate of a mobile body, comprising step (a) comprising determining at least three distances of the mobile body from at least three signal generators, each distance being a distance between the mobile body and one of the at least three signal generators. In this regard, each of the at least three signal generators has a predefined position relative to a moving coordinate system, the moving coordinate system being a coordinate system in which the position of a stationary object may change due to movement of a coordinate origin. The method further comprises step (b) comprising determining and / or improving a position estimate of the mobile body by using the at least three determined distances of the mobile body from the at least three signal generators and the predefined positions of the at least three signal generators relative to the moving coordinate system.

[0006] Further embodiments according to the present invention include a mobile body or a module for the mobile body configured to determine at least three distances of the mobile body from at least three signal generators, each distance being a distance between the mobile body and one of the at least three signal generators, where each of the at least three signal generators has a predefined position relative to a moving coordinate system, the moving coordinate system being a coordinate system in which the position of a stationary object may change due to a displacement of a coordinate origin. Furthermore, the mobile body or module is configured to determine and / or improve a position estimate of the mobile body by using the at least three determined distances of the mobile body from the at least three signal generators and the predefined positions of the at least three signal generators relative to the moving coordinate system.

[0007] A further embodiment according to the present invention includes a system for determining and / or improving a position estimate of a mobile body, the system including a mobile body as previously described and at least three signal generators, each of the at least three signal generators having a predefined position relative to a mobile coordinate system.

[0008] A further embodiment according to the invention comprises a computer program having a program code for performing the method according to the invention when the program runs on a computer.

[0009] An embodiment according to the present invention is based on the core idea of determining and / or improving a position estimate of a mobile object by determining at least three distances of the mobile object from at least three signal generators. Due to the at least three distances of the mobile object from the at least three signal generators, the relative position of the mobile object can be determined from the at least three signal generators, for example, by triangulation. Here, each of the at least three signal generators has a predefined position with respect to a mobile coordinate system. Therefore, the at least three determined distances of the mobile object from the at least three signal generators also reveal the relative position of the mobile object with respect to the mobile coordinate system. Therefore, navigation of the mobile object with respect to the mobile coordinate system can be performed. In this context, moving with respect to a coordinate system includes the possibility that the position of a stationary object with respect to the mobile coordinate system may change due to a movement of the coordinate origin of the coordinate system. Specifically, the mobile coordinate system can be associated with, for example, a moving ship, such that the mobile coordinate system moves with the movement of the ship with respect to global coordinates, such as GPS coordinates. Therefore, the mobile coordinate system may be a non-inertial system.

[0010] The signal generator may have a predefined but variable position with respect to the coordinate system. If the signal generator performs a known, e.g., measurable, relative movement with respect to the coordinate origin, then a distance determination of the mobile body to the signal generator can be translated into a position with respect to the moving coordinate system by the variable but known relative position of the signal generator. In the case of a fleet of ships, the signal generators may, for example, be located on different ships, but the different ships have known positions with respect to each other.

[0011] In particular, it should be noted that the coordinate system can be expanded by at least three signal generators. For example, the signal generators can have predefined positions in the coordinate system. Thus, the coordinate system can be formed such that a first signal generator is located at a first fixed position on a first axis of the coordinate system, a second signal generator is located at a second fixed position on a second axis of the coordinate system that is perpendicular to the first axis, and a third signal generator is located on a third axis of the coordinate system that is perpendicular to the first and second axes of the coordinate system. However, each of the signal generators can also be assigned to any position in the moving coordinate system, and the coordinate system can be expanded based on the determined positions of the signal generators.

[0012] However, for example, the moving coordinate system may be distorted or bent by the movement of the signal generators. For example, a set of signal generators may be arranged along the object, and the set of signal generators may span a first axis of the coordinate system, with each of the signal generators having a fixed position on the spanned axis. Furthermore, the signal generators may span, for example, two additional axes of a three-dimensional coordinate system. When the object is bent, the relative positions of the signal generators in global coordinates, such as GPS coordinates, may change relative to each other, and according to their fixed positions on the first axis of the moving coordinate system, the moving coordinate system may bend along with the bending of the object. For example, a moving body navigating with respect to this coordinate system would only move parallel to the first bent axis of the moving coordinate system if the moving body were to move parallel to the bent object. This allows the moving body to move particularly effectively relative to the moving coordinate system.

[0013] However, changes in the shape of the object, to which the coordinate origin of the moving coordinate system is associated, can also be taken into account by adapting a model of the object. For example, the trajectory planning can be based on a model, such as a CAD model of the object in the moving coordinate system. Changes in the shape of the object, known for example by measurements, can now be mapped into the model, and trajectory planning can be performed on the basis thereof.

[0014] Another advantage of the inventive concept is that a mobile object can determine its own position information very quickly. The distance determination to each signal generator can be performed faster than, for example, a GPS position determination. Speed refers to the update rate of the position information. In many applications, the update rate of the position information, for example, via GPS, is not sufficient to track the trajectory relative to a moving coordinate system with sufficient accuracy. In the case of a drone landing on a moving ship, a position determination relative to the ship that takes into account the rapidly changing position of the ship over time, especially with respect to vertical motion caused by waves, is advantageous. Therefore, during an automatic landing, it is possible to avoid the drone landing on the deck with too high an acceleration and being damaged or destroyed due to wave-induced movements on the ship that are unknown to the drone.

[0015] In a further embodiment according to the present invention, step (a) includes transmitting transmission signals from the mobile unit to at least three signal generators and receiving response signals from the at least three signal generators by the mobile unit. Further, a step of determining at least three distances of the mobile unit from the at least three signal generators based on the received response signals is performed. Further, step (a) and step (b) are performed by the mobile unit.

[0016] For example, the response signal can include multiple individual signals, such that each individual signal generator responds to the transmission signal with an individual signal. From the response signals from the signal generators, the mobile body can then determine the distance to the corresponding signal generator, for example, based on a time measurement. Briefly, according to an embodiment, the mobile body can transmit a transmission signal that is incident on at least three signal generators. In response to the received transmission signal, each of the signal generators can transmit a response signal, which is then detected by the mobile body. The mobile body can have its own intelligence, for example, to evaluate the signal, calculate the travel time, and then calculate the distance to each signal generator. Furthermore, the signal generator can also analyze the signal from the drone before sending the response signal. For example, the drone can transmit status information or information about its own location through communication with the signal generator.

[0017] In an embodiment according to the invention, each of the at least three signal generators has a predefined, unchanging position relative to the moving coordinate system. The unchanging position of the signal generators relative to the moving coordinate system provides the advantage that relative movements between the signal generators and the moving coordinate system do not have to be taken into account. For example, the moving coordinate system itself can be spanned by the signal generators, and the signal generators can now have predefined, unchanging positions relative to each other, and the signal generators can only move as a whole, i.e., while maintaining their predefined, unchanging positions relative to each other.

[0018] According to an embodiment of the present invention, a moving object can have a predefined, unchanging position with respect to a moving coordinate system, the movement of which corresponds to the physical movement of the object. Specifically, the object can be, for example, a moving ship. The coordinate origin of the moving coordinate system here can be, for example, a point on the surface of the ship. Thus, as the ship moves, the moving coordinate system also moves with respect to an inertial system, such as global coordinates or GPS coordinates. Here, for example, a signal generator can be rigidly connected to the object, so that the signal generator has a previously stated, predefined, unchanging position with respect to the coordinate system. However, in the case of an object such as a ship, the signal generator can also be located on one or more escort ships whose positions relative to the moving ship are known, with the coordinate origin of the moving coordinate system fixed on its surface. By coupling between the movement of the object and the movement of the moving coordinate system, navigation of the moving body with respect to the moving object can be performed by determining its position with respect to the moving coordinate system.

[0019] In an embodiment according to the present invention, step (a) additionally includes obtaining GPS information about the position of the moving object, and step (b) includes using the GPS information to determine and / or improve the position estimate of the moving object. For example, by using the GPS information, the relative position of the moving object from the object, determined by the three distances of the moving object from the signal generator, can be converted into GPS coordinates. This option of determining the position of the moving object in global coordinates can be particularly advantageous when the position of the moving object in GPS coordinates is available with higher accuracy than the position of the moving object in GPS coordinates. For example, a ship as a moving object may have a more accurate positioning system for determining its own position than, for example, a drone, which can form a moving object. In contrast, distance determination by the signal generator is possible with high accuracy. Therefore, for example, in the case of a drone, accurate position determination can be performed at low cost and with less effort. For example, if a drone is used only within a close range around the object equipped with the signal generator, the drone's GPS system can be completely omitted, which can provide cost advantages.

[0020] According to an embodiment of the present invention, the position estimation is a position estimation with respect to a moving coordinate system or a position estimation with respect to an absolute coordinate system. The absolute coordinate system may be at least approximately an inertial system. For example, the absolute coordinate system may be a coordinate system in a global coordinate system, for example, using GPS coordinates. However, the position estimation can also be performed with respect to a moving coordinate system and an absolute coordinate system. This provides the mobile body with absolute position information, on the one hand, for example, to avoid collisions with known, for example, mapped, obstacles in the environment, and with relative position information, on the other hand, for example, to enable short-distance inspection of moving objects.

[0021] According to an embodiment of the present invention, the method may include an additional step (c). In this case, step (c) includes determining GPS information about the position of the mobile body and determining and / or improving a position estimation of the mobile body by using the GPS information about the position of the mobile body. In this way, for example, data fusion can be performed in which the determined GPS information about the position of the mobile body is fused on the one hand and the relative position of the mobile body with respect to the mobile coordinate system is fused on the other hand. Furthermore, if the GPS coordinate of the coordinate origin of the mobile coordinate system is known, the information about the relative position of the mobile body with respect to the mobile coordinate system can be converted into GPS coordinate information. For example, this information can then be fused with the GPS information about the position of the mobile body to achieve an improved position estimation of the mobile body. Here, the GPS system can be accommodated, for example, in the mobile body itself.

[0022] In an embodiment according to the present invention, step (c) is performed when the mobile body is at least a first distance from the moving object, and steps (a) and (b) are performed when the mobile body is at a distance from the moving object that is shorter than the first distance. For example, the first distance may be a range for signal transmission between the mobile body and the signal generator. For example, the first distance may be 10 km. Briefly, for example, outside the range of the signal generator, navigation of the mobile body can be performed solely based on GPS information determined about the mobile body's position, while within the range, navigation can be performed solely based on information about the mobile body's precisely determined distance from at least three signal generators and the signal generator's position relative to the moving coordinate system. For example, in the case of a drone grid search around a ship, a wide-range GPS-based position determination of the drone around the ship may be sufficient, while, for example, automatic landing requires the use of more precise position determination and distance-based relative position determination with respect to the ship.

[0023] According to an embodiment of the present invention, step (c) is performed when the mobile body is at least a first distance from the moving object, and steps (a), (b), and (c) are performed when the mobile body is at a distance from the moving object that is less than the first distance. Therefore, the determination of GPS information about the position of the mobile body can continue further within the range of the signal generator to achieve an improved position estimate of the mobile body, for example, by data fusion as described above. Therefore, the position estimate of the mobile body can be accurately determined or improved.

[0024] According to a further embodiment of the present invention, the method includes an additional step (d), which includes navigating the mobile body based on the position estimation. Improved position estimation can reduce the likelihood of collisions and, for example, in the case of inspection tasks, improve inspection accuracy by allowing a shorter distance to the object or objects to be inspected. Accordingly, an embodiment according to the present invention includes the concept of establishing a GPS-independent positioning system by triangulation based on the coordinates of the signal generator, e.g., based on the coordinates of an installed radio beacon. This can enable navigation with centimeter accuracy. According to an embodiment, navigation can be based on a determined distance to the signal generator, replacing GPS coordinates, or the distance information can be combined with GPS data, e.g., correcting the GPS coordinates. Furthermore, it is also possible to switch back and forth between GPS or GPS navigation and navigation based on distance information from the signal generator or signal generator information. These navigation options can be used in any combination, e.g., for autonomous control of the mobile body, e.g., for autonomous flight of a drone.

[0025] According to an embodiment of the present invention, step (d) includes generating waypoints for the moving trajectory of the moving object and adapting the waypoints based on the movement of the moving coordinate system. For example, in a landing approach of a drone to a ship, the landing approach movement trajectory can be adapted with respect to the movement of the ship. This allows the moving object to navigate with increased safety, especially in close proximity to moving objects.

[0026] According to an embodiment of the present invention, step (d) includes predicting the movement of the moving coordinate system and adapting the waypoint based on the predicted movement of the moving coordinate system. For example, for the movement prediction, the signal generator and / or the object can be equipped with sensor elements to detect the movement of the moving coordinate system. Specifically, for example, the signal generator can also be fixedly mounted on the object on which the moving coordinate system is spread. By using gyroscopes and accelerometers, for example, in the signal generator or in the object itself, the movement of the object, and therefore the moving coordinate system, can be both detected and predicted. Thus, the trajectory of the moving body can be adapted according to the predicted movement of the coordinate system or the object. For example, again in the case of a ship, vertical movement due to waves can be predicted in this way, so that, for example, an automatic landing approach for a drone as a moving body can be planned, so that the drone lands in an automated manner during the downward movement of the ship. This can, for example, prevent an unforeseen upward movement of the ship due to waves from landing the drone hard on the deck of the ship, resulting in damage or destruction.

[0027] According to an embodiment of the present invention, step (d) comprises a fully automated takeoff and / or landing on the moving object. For this, the previously described adaptation of the moving object's movement trajectory can be used, for example. By predicting the object's movement, a fully automated takeoff and / or landing can thus be performed without, or for example with little risk of collision or excessive acceleration of the moving object. However, for takeoff and / or landing on the moving object, in addition to the position and movement information of the moving object or object, environmental information, for example about wind, humidity, temperature, can also be taken into account.

[0028] Thus, according to embodiments, a fully automated takeoff and / or landing of / on a moving object can be performed by tracking the movement of the object. In the case of a moving ship as the object, for example, compensation for wave movement can be performed or implemented. Also, for example, when inspecting an offshore wind turbine in swells with a supply ship, compensation for wave movement can be performed, and at least three signal generators, for example in the form of at least three radio beacons, can be installed at the landing site. During takeoff and / or landing, the mobile object, for example, a drone, can switch its positioning or navigation to the inventive concept or system, for example, comprising at least three beacons, and / or use GPS data corrected by, for example, local intelligence, for example, by conversion by a processing unit that is part of the mobile object.

[0029] According to an embodiment of the present invention, the moving object may be a ship, an airship, an oil or gas platform, an offshore wind turbine, or a skyscraper. However, regardless of the type of object, the bending of the entire object may also be taken into account. For example, a skyscraper may bend due to strong winds, which may result in the top of the skyscraper swinging several meters. For example, for such a use case, the object may have multiple sensors capable of detecting the bending of the object. For example, the sensors may be placed at specific intervals along the surface of the object, and the bending of the object may be determined. The bending of the object may then be mapped, for example, by fitting a model of the object in a moving coordinate system, or the coordinate system itself may be curved, for example. Thus, the coordinate axes of the moving coordinate system may be associated with the surface of the curved object, such as being aligned with the surface of the curved object. In simple terms, the coordinate system may follow the bending of its associated object. In contrast, a floating oil or gas platform may move laterally without bending, for example, due to wave action. Furthermore, it should be noted that predicting the movement of an object can also include predicting the bending of the object. For example, the bending of the top of a skyscraper in strong winds can be predicted for the landing of an autonomous helicopter, for example, by adapting the landing trajectory.

[0030] According to a further embodiment of the present invention, the at least three signal generators comprise at least one of a radio beacon, an optical beacon, and / or an acoustic beacon. According to the embodiment, multiple signals are possible, which are exchanged between the mobile unit and the signal generators. Therefore, depending on the application, a technically convenient signal transmission can be used. The radio beacon can operate on radio waves having a frequency of, for example, 5 GHz or, for example, 4 GHz, or having a frequency or frequency range in the range of 2.4 GHz to 9.5 GHz, for example, in the range of 2.4 GHz, or, for example, in the range of 4 GHz, or, for example, in the range of 5 GHz. The mobile unit can operate in a corresponding frequency range. More generally, the mobile unit and the signal generator can be tuned to a corresponding frequency range to enable the exchange of signals.

[0031] According to an embodiment of the present invention, the moving body is a drone, a submarine, a helicopter, an airplane, an airship, or a ship. Navigation with respect to a moving coordinate system can therefore be used in a variety of applications.

[0032] According to an embodiment of the present invention, the system of the present invention includes a moving object, such as the moving object described above, where the moving object has a predefined, unchanging position relative to a moving coordinate system, and movement of the moving coordinate system corresponds to physical movement of the object. The system of the present invention, including a moving body, a signal generator, and the moving object, enables effective and accurate navigation of the moving body relative to the object.

[0033] Examples of embodiments according to the invention are explained in more detail below with reference to the accompanying drawings. With regard to the illustrated schematic diagrams, it should be noted that the illustrated functional blocks should be considered both as elements or features of the apparatus of the invention and as corresponding method steps of the method of the invention, which corresponding method steps of the method of the invention can also be derived therefrom. The figures show: [Brief explanation of the drawings]

[0034] [Figure 1] 1 is a schematic diagram of a moving body, three signal generators, and a moving coordinate system for use in a method according to an embodiment of the present invention; [Figure 2] 1 is a schematic diagram of a system including a moving body and three signal generators, as well as a moving coordinate system and a moving object, according to an embodiment of the present invention. [Figure 3] 1 is a schematic diagram of a navigation system for a mobile object according to an embodiment of the present invention; [Figure 4] 1 is a flow diagram of a process according to an embodiment of the present invention. [Figure 5] FIG. 2 is a schematic diagram of a skyscraper as an object, in which the curvature of the object is mapped in a moving coordinate system, according to an embodiment of the present invention. [Figure 6] 1 is a schematic diagram of information processing for determining and / or improving a position estimate of a mobile body according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0035] Before the embodiments of the present invention are described in detail below with reference to the drawings, it should be noted that identical, functionally equivalent or similar elements, objects and / or structures are provided with the same or similar reference numbers in different drawings, so that the descriptions of these elements described in different embodiments are interchangeable or mutually applicable.

[0036] Figure 1 shows a schematic diagram of a moving object, three signal generators, and a moving coordinate system for use in a method according to an embodiment of the present invention. Figure 1 shows an example moving object 110 in the form of a drone, signal generators 120a-c, and a moving coordinate system 130 with a coordinate origin 140.

[0037] Optionally, GPS information about the location of the mobile unit can be determined. The location estimate of the mobile unit 110 can be made in relative or absolute coordinates, e.g., with respect to an inertial or non-inertial system, e.g., with respect to global coordinates, e.g., GPS coordinates, or with respect to a mobile coordinate system. The uncertainty of the location estimate of the mobile unit 110 in the case of known GPS information about the mobile unit's location is illustrated in FIG. 1.

[0038] By determining the distances 160a-c of the mobile unit 110 from the signal generator 120, the position of the mobile unit 110 can be determined or a position estimate of the mobile unit 110 can be improved. The uncertainty of the improved position estimate 170, taking into account the determined distances 160a-c, is also plotted in FIG. 1. Such uncertainty can optionally be determined, for example, by taking into account uncertainty in the distance determination. However, according to embodiments, the position of the mobile unit can also be determined without determining an uncertainty or confidence interval.

[0039] Each of the signal generators 120a-c has a predefined position (x1 / y1)-(x3 / y3) with respect to the moving coordinate system. Therefore, the determined distances 160a-c can be used to determine the position of the moving object 110 with respect to the moving coordinate system 130. Furthermore, the positions of the signal generators may be with respect to an absolute coordinate system, such as global coordinates, so that the position of the moving object 110 in the global or absolute coordinates can be determined therefrom.

[0040] The method according to the invention may optionally further comprise the step of determining GPS information about the position of the mobile body. The position estimation may be performed, for example, with respect to an inertial or non-inertial system, for example in relative or absolute coordinates.

[0041] Optionally, to determine the distance 160a-c, the mobile 110 can emit a transmission signal that is detected by the signal generators 120a-c. The signal generators 120a-c then transmit a response signal that is received by the mobile 110. The determination of the distance 160a-c can then be made thereafter based on the response signal, which can include, for example, a set of partial signals from one of the signal generators 120a-c. The distance determination can be made, for example, by time measurement. For example, the distance can be determined by the time period between sending the transmission signal and receiving the response signal.

[0042] The predefined positions of the signal generators with respect to the coordinate system 130 include the fact that the positions (x1 / y1) to (x3 / y3) are known. However, these positions do not necessarily have to be fixed. The signal generators 120a-c may also have predefined, fixed positions (x1 / y1) to (x3 / y3) with respect to the moving coordinate system 130.

[0043] 2 shows a schematic diagram of a system including a moving body and three signal generators, as well as a moving coordinate system and a moving object, according to an embodiment of the present invention. FIG. 2 shows the elements already described in FIG. 1 and additionally shows an object 210. The system 220 includes the moving body 110 and the signal generator 120.

[0044] Optionally, the system can further include an object 210. The object may be, for example, a ship. As shown in FIG. 2 , the signal generator 120 can be mounted on the object. Furthermore, the coordinate system 130 is spread based on the surface of the object 210. Thus, movement of the moving coordinate system 130 corresponds to physical movement of the object 210. Each signal generator 120 has a predefined, unchanging position with respect to the coordinate system 130. By determining the distance 160, the mobile unit 110 can navigate very close to the object 210 or, for example, take off or land automatically, because the determination of the coordinate system, and therefore the position relative to the object, of the present invention can keep the risk of collision with the object 210 low.

[0045] Additionally, GPS information about the location of the object 210 can optionally be obtained or determined. This information can then be used to improve the location estimation of the mobile unit 110. If the mobile coordinate system 130 is expanded based on the object surface, as shown in Figure 3, the GPS location of the object 210 can also be used to infer the GPS location of the mobile unit by evaluating the distance from the mobile unit 110 to the signal generator 120.

[0046] Additionally, GPS information about the location of the mobile unit 110 can be optionally determined. This GPS information, such as GPS coordinates with estimated uncertainties as shown in FIG. 1 by circle 150, can be used to determine and / or refine a location estimate for the mobile unit 110.

[0047] In this regard, GPS information about the location of the mobile unit 110 can be used alone, for example, outside of communication range between the signal generator and the mobile unit, to navigate the mobile unit 110. Within communication range, the GPS information can be used as additional information for data fusion along with the determined distance 160 of the mobile unit 110 to the signal generator 120 for position determination / refinement, or the GPS information can be substituted for navigation using only the determined distance 160.

[0048] FIG. 3 shows a schematic diagram of navigation of a mobile body according to an embodiment of the present invention. FIG. 3 illustrates a landing approach of a mobile body 110 to an object 210. As an example, the mobile body 110 is shown as a drone, and the object 210 is shown as a ship. Based on a position estimate of the mobile body 110, a moving trajectory 310 including a waypoint 320, for example, for landing, can be planned. For example, as shown in FIG. 3, when the object 210 is moving on a moving wave W, the waypoint can be adapted based on the movement of the moving coordinate system or the moving object 210. In particular, as shown in FIG. 3, this adaptation can be performed based on a prediction of the movement of the moving coordinate system, such that the mobile body 110, taking into account its own flight time, adapts the trajectory 310 to a trajectory 330 including a waypoint 340 and lands on the object taking into account the movement of the object 210. As a result, such landing or, for example, takeoff can be fully automated.

[0049] Sensor data can be used for the prediction. For example, a signal generator can include sensors such as accelerometers or gyroscopes, or sensors can be placed on the object. Furthermore, the prediction can be calculated based on a CAD model of the object. The model can also be used to take into account twisting or bending of the object. For example, force sensors on the object can be used to map the movement and / or deformation of the object, which can then be used to navigate a vehicle relative to the object with high accuracy. This can be particularly advantageous for very large objects, because due to the dimensions of the object, even small deformations, for example, related to the height of a skyscraper or the length of a cargo ship, can result in significant changes in the positions of elements of the object.

[0050] FIG. 4 shows a flow chart of a method according to an embodiment of the present invention. Method 400 for determining and / or improving a position estimate of a mobile object includes step 410, which includes determining at least three distances of the mobile object from at least three signal generators, each distance being a distance between the mobile object and one of the at least three signal generators, each of the at least three signal generators having a predefined position relative to a moving coordinate system, the moving coordinate system being a coordinate system in which the position of a stationary object may change due to movement of a coordinate origin. Furthermore, method 400 includes step 420, which includes determining and / or improving a position estimate of the mobile object using the at least three determined distances of the mobile object from the at least three signal generators and the predefined positions of the at least three signal generators relative to the moving coordinate system. In this regard, steps 410 and 420 may correspond to steps (a) and (b) previously described.

[0051] FIG. 5 shows a schematic diagram of a skyscraper as an object, and according to an embodiment of the present invention, the curvature of the object is mapped in a moving coordinate system. FIG. 5 shows an example object 210 in the form of a skyscraper. Due to wind, the top of the skyscraper may sway by several meters. This effect is strongly exaggerated in FIG. 5. The signal generator 120 is located on the object 210. The moving coordinate system 130 is extended by the surface of the object. The object further comprises a sensor 510, which is located on the surface of the object 210. As an example, the sensor 510 is located here on the axis of the moving coordinate system 130, but the sensor 510 can also be located anywhere relative to the moving coordinate system 130. The sensor 510 is configured to detect the curvature of the object 210. Based on the measured curvature, the moving coordinate system 130 follows the surface of the object 210. For example, for inspection, a drone can now navigate with respect to a distance from a curved axis without colliding with the curved object 210. Such bending can also be taken into account in a corresponding model of the object 210. Such consideration of the object deformation can be used, for example, to navigate the vehicle 110 relative to the rotor blades of a wind turbine. Due to their length, the rotor blades may have deflections that can be taken into account to avoid collisions with an inspecting drone.

[0052] FIG. 6 shows a schematic diagram of information processing for determining and / or refining a position estimate of a mobile body according to an embodiment of the present invention. FIG. 6 illustrates step 420 of FIG. 4 , which includes determining and / or refining a position estimate of a mobile body using at least three determined distances 160 of the mobile body from at least three signal generators and predefined positions 620 of the at least three signal generators with respect to a mobile coordinate system, e.g., positions (x1 / y1)-(x3 / y3) in FIG. 1 . Further optional information that may be processed in step 420 includes GPS information 630 about the position of an object, GPS information 640 about the position of the mobile body, and sensor information 650 from sensors of the object and / or the signal generators. For example, GPS information 630 about the position of the object and GPS information 640 about the position of the mobile body may each include GPS coordinates of the object and the mobile body, respectively.

[0053] For example, in the case of a ship as the object and a drone as the mobile body, the ship can send its own GPS position 630 to the drone, and the drone can perform step 420 based on the at least three determined distances 160 of the drone from the at least three signal generators and the predefined positions 620 of the at least three signal generators with respect to the mobile coordinate system, as well as its own position 640 determined using the GPS module.

[0054] For example, sensor information 650 from sensors of the object and / or signal generator may include acceleration information, such as sensor information from an acceleration or gyro sensor. If a predefined position in a moving coordinate system is aligned with the sensor, curvature of the object may be taken into account, for example, as illustrated in FIG. 5. It should be noted that GPS information 630 about the position of the object, GPS information 640 about the position of the mobile body, and sensor information 650 from sensors of the object and / or signal generator may each be used separately or in any combination in step 420.

[0055] More generally, embodiments according to the present invention thus realize the concept for tracking and / or tracing an object. The object may be a running, driven, or moving object. For example, by correcting GPS coordinates, inspection of such an object can be performed according to the present invention by using a homing function, for example, from a supply ship. The homing function can be performed, for example, by navigating the mobile object using at least three determined distances of the mobile object from at least three signal generators. Functions can include, for example, automatic navigation or homing to the object, as well as, for example, additionally or alternatively, an automatic landing function, for example, for a drone as the mobile object. Inspection can thus be performed while in motion, for example, from a moving ship or other moving object, in particular.

[0056] Furthermore, according to the present invention, any search pattern can be performed by the mobile body parallel to the moving object. For example, a drone can perform any search pattern in the vicinity of a moving ship, for example, parallel to the movement of the ship, e.g., a sea rescue ship, by converting determined distances or distance values to correct a position estimate, e.g., GPS coordinates. Additionally or alternatively, a position estimate, e.g., in the form of GPS coordinates, of a moving object, e.g., a moving ship, can also be transmitted for correcting or estimating the position of a mobile body, e.g., a moving drone. In this case, for example, the landing or return of the mobile body can be controlled solely by determining the distance of the mobile body from the signal generator.

[0057] More generally, embodiments according to the present invention provide a concept for inspecting a moving object. The moving object may be, for example, an anchored floating oil or gas platform. For example, a triangulation system can be set up using at least three signal generators, for example, in the form of radio beacons, on the movable or moving object. The set-up or calculation of the moving coordinate system can be based on triangulation of the coordinates of the installed signal generators or radio beacons. Furthermore, dynamic adaptation or transformation of coordinates to the movement of the object can be performed. For example, changes in position or distance data or changes in position can be detected by changes in distance data of the signal generators or radio beacons. A moving object, for example, a drone, can hereby follow the movement of the object or follow a predefined movement trajectory for the moving object. Furthermore, the transformation of, for example, CAD data of the object into a moving coordinate system for dynamic waypoint (waypoint) generation of the moving object, for example, a drone, can be performed using, for example, local intelligence.

[0058] Additionally, another advantage or application field of the inventive concept is centimeter-precise mobile control, for example, centimeter-precise drone flight in GPS shadow areas inside objects or structures, such as under bridges, in factories (such as refineries), or indoors. By using a suitable frequency range, for example in the GHz range, the signal between the mobile and the signal generator can penetrate obstacles such as walls.

[0059] All lists of materials, environmental effects, electrical properties, and optical properties mentioned herein should be considered as examples and not exhaustive.

[0060] Although some aspects are described in the context of an apparatus, it is clear that these aspects also represent a description of the corresponding method, such that an apparatus block or device also corresponds to a respective method step or feature of a method step. Similarly, aspects described in the context of a method step also represent a description of a corresponding block or detail or feature of the corresponding apparatus. Some or all of the method steps can be performed by (or using) a hardware apparatus, such as a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, some or some of the most important method steps can be performed by such an apparatus.

[0061] Depending on certain implementation requirements, embodiments of the present invention can be implemented in hardware or software. The implementations can be implemented using, for example, digital storage media such as floppy disks, DVDs, Blu-ray disks, CDs, ROMs, PROMs, EPROMs, EEPROMs, or flash memories, hard drives, or other magnetic or optical memories having electrically readable control signals stored thereon, which cooperate or are capable of cooperating with a programmable computer system to implement the respective methods. Thus, the digital storage media can be computer-readable.

[0062] Some embodiments according to the invention include a data carrier containing electronically readable control signals capable of cooperating with a programmable computer system to perform one of the methods described herein.

[0063] Generally, embodiments of the present invention can be implemented as a computer program product having program code that is operable to perform one of the methods when the computer program product is run on a computer.

[0064] For example, the program code may be stored on a machine readable carrier.

[0065] Other embodiments comprise the computer program for performing one of the methods described herein, wherein the computer program is stored on a machine readable carrier.

[0066] In other words, an embodiment of the inventive method is, therefore, a computer program comprising a program code for performing one of the methods described herein, when the computer program runs on a computer.

[0067] A further embodiment of the inventive method is therefore a data carrier (or digital storage medium or computer-readable medium) having recorded thereon a computer program for performing one of the methods described herein. The data carrier, digital storage medium, or computer-readable medium is typically tangible or non-volatile.

[0068] A further embodiment of the inventive method is, therefore, a data stream or a sequence of signals representing the computer program for performing one of the methods described herein. For example, the data stream or the sequence of signals can be adapted to be transferred via a data communication connection, for example via the Internet.

[0069] A further embodiment comprises a processing means, for example a computer, or a programmable logic device, configured to or adapted to perform one of the methods described herein.

[0070] A further embodiment comprises a computer having installed thereon the computer program for performing one of the methods described herein.

[0071] Further embodiments according to the invention include an apparatus or system configured to transmit a computer program for performing at least one of the methods described herein to a receiver. The transmission may be, for example, electrical or optical. The receiver may be, for example, a computer, a mobile device, a memory device, or a similar device. The apparatus or system may, for example, include a file server for transmitting the computer program to the receiver.

[0072] In some embodiments, a programmable logic device (e.g., a field programmable gate array, FPGA) can be used to implement some or all of the functionality of the methods described herein. In some embodiments, a field programmable gate array can cooperate with a microprocessor to implement one of the methods described herein. In general, the methods are preferably implemented by any hardware apparatus. This may be generally applicable hardware such as a computer processor (CPU) or hardware dedicated to the methods, such as an ASIC.

[0073] The apparatus described herein may be implemented, for example, using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer.

[0074] The devices described herein or any components of the devices described herein may be implemented at least in part in hardware and / or software (computer programs).

[0075] The methods described herein can be implemented, for example, by using a hardware apparatus, or by using a computer, or by using a combination of a hardware apparatus and a computer.

[0076] The methods described herein, or any components of the methods described herein, may be implemented at least in part by hardware and / or software (computer programs).

[0077] The above-described embodiments are merely illustrative of the principles of the present invention. It is understood that modifications and variations of the arrangements and details described herein will be apparent to those skilled in the art. It is therefore intended that the present invention be limited only by the scope of the appended claims, and not by the specific details presented by the description and illustration of the embodiments herein. [Explanation of symbols]

[0078] 110 Mobile 120 Signal Generator 120a signal generator 120b signal generator 120c signal generator 130 Moving Coordinate System 140 Coordinate origin 150 yen 160 distance 160a distance 160b distance 160c distance 210 Object 220 System 310 orbit, moving orbit 320 Midpoint 330 orbit, moving orbit 340 Midpoint 400 ways 410 Step (a) 420 Step (b) 510 Sensors 620 position 630 GPS information 640 GPS information, location 650 Sensor Information

Claims

1. A method (400) for determining and / or improving a position estimate of a mobile unit (110), comprising: (a) determining at least three distances (160) of the moving body (110) from at least three signal generators (120), each of the distances being a distance between the moving body (110) and one of the at least three signal generators; each of the at least three signal generators (120) having a predefined position relative to a moving coordinate system (130); the moving coordinate system (130) is a coordinate system in which the position of a stationary object can change due to movement of a coordinate origin (140); (b) the at least three determined distances (160) of the moving object (110) from the at least three signal generators (120); and the predefined positions (620) of the at least three signal generators (120) relative to the moving coordinate system (130); determining and / or improving the location estimate of the mobile unit (110) by using Including, the method includes an additional step (d), which includes navigating the mobile unit (110) based on the position estimate; the step (d) includes a step of generating intermediate points (320, 340) for the movement trajectory (310, 330) of the moving object (110); The method (400), wherein step (d) includes adapting the intermediate points (320, 340) based on a movement of the moving coordinate system (130).

2. Step (a) (410) Emitting a transmission signal from the mobile unit (110) to the at least three signal generators (120); receiving, by said mobile unit (110), response signals from said at least three signal generators (120); Including, determining the at least three distances (160) of the moving object (110) from the at least three signal generators (120) based on the received response signals; 2. The method (400) of claim 1, wherein step (a) (410) and step (b) (420) are performed by the moving entity (110).

3. 10. The method of claim 1, wherein each of the at least three signal generators has a predefined, invariant position with respect to the moving coordinate system.

4. 10. The method of claim 1, wherein a moving object has a predefined, unchanging position relative to the moving coordinate system, and movement of the moving coordinate system corresponds to physical movement of the object.

5. 5. The method (400) of claim 4, wherein step (a) further comprises obtaining GPS information (630) about the location of the moving object (210), and step (b) (420) comprises determining and / or improving the location estimate of the moving body (110) by using the GPS information.

6. The location estimation is with respect to said moving coordinate system, or a position estimate with respect to an absolute coordinate system, 2. The method (400) of claim 1, wherein the absolute coordinate system is at least approximately an inertial system.

7. The method includes the additional step (c), wherein step (c) comprises: determining GPS information (640) about the location of the mobile unit (110); determining and / or improving the location estimate of the mobile unit (110) by using the GPS information about the location of the mobile unit; 2. The method (400) of claim 1, comprising:

8. Step (c) is performed when the moving body (110) is at least a first distance from the moving object (210); 8. The method (400) of claim 7, wherein step (a) (410) and step (b) (420) are performed when the moving body (110) is at a distance from the moving object (210) that is less than the first distance.

9. Step (c) is performed when the moving body (110) is at least a first distance from the moving object (210); 8. The method (400) of claim 7, wherein steps (a) (410), (b) (420), and (c) are performed when the moving body (110) is at a distance from the moving object (210) that is less than the first distance.

10. step (d) includes predicting the movement of the moving coordinate system (130); 2. The method (400) of claim 1, wherein step (d) comprises adapting the intermediate points (320, 340) based on the predicted movement of the moving coordinate system (130).

11. 10. The method (400) of claim 1, wherein step (d) includes fully automated takeoff and / or landing on the moving object (210).

12. The method (400) of claim 1, wherein the moving object (210) is a ship, an airship, an oil or gas platform, an offshore wind turbine, or a skyscraper.

13. 10. The method of claim 1, wherein the at least three signal generators include at least one of a radio beacon, an optical beacon, and / or an acoustic beacon.

14. The method (400) of claim 1, wherein the vehicle (110) is a drone, a submarine, a helicopter, an airplane, an airship, or a ship.

15. A mobile unit (110) or a module for a mobile unit (110), comprising: determining at least three distances (160) of a moving object (110) from at least three signal generators (120), each of the distances being a distance between the moving object (110) and one of the at least three signal generators (120), each of the at least three signal generators having a predefined position relative to a moving coordinate system (130); determining that the moving coordinate system (130) is a coordinate system in which the position of a stationary object can change due to a displacement of a coordinate origin (140); the at least three determined distances (160) of the moving object (110) from the at least three signal generators (120); and the predefined positions of the at least three signal generators (120) relative to the moving coordinate system (130); determining and / or improving a position estimate of the mobile unit (110) by using generating intermediate points (320, 340) for the movement trajectory (310, 330) of the moving body (110) and adapting the intermediate points (320, 340) based on the movement of the moving coordinate system (130); navigating the moving body (110) based on the position estimate by A mobile unit (110) or a module for a mobile unit (110) configured to:

16. A system (220) for determining and / or improving a position estimate of a mobile unit (110), comprising: A moving body (110) according to claim 15; the at least three signal generators, each of the at least three signal generators having a predefined position with respect to the moving coordinate system (130); A system (220) comprising:

17. 17. The system (220) of claim 16, comprising a moving object (210), the moving object having a predefined, unchanging position relative to the moving coordinate system (130), and movement of the moving coordinate system corresponding to physical movement of the object (210).

18. A computer program having a program code for performing the method (400) of claim 1 when the program runs on a computer.

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