Method, computer program, device and graphical display element for positioning a vehicle, and vehicle

Abstract

The invention relates to a method for positioning a vehicle (2), having a mobile inductive charging apparatus (1a), in a defined position with respect to a stationary inductive charging apparatus (1b), wherein a positioning signal generated in one of the two inductive charging apparatuses (1a, 1b) induces at least one voltage signal (13a, 13b) in the other of the two inductive charging apparatuses (1a, 1b), a relative distance between the mobile inductive charging apparatus (1a) and the stationary inductive charging apparatus (1b) is approximated from the induced voltage signal (13a, 13b), and a directional deviation of the vehicle from a target direction in relation to the stationary inductive charging apparatus is ascertained using a parking space detection sensor.

Description

[0001] Method, computer program, device and graphic display element for positioning a vehicle and vehicle

[0002] The invention relates to a method for positioning a vehicle according to the preamble of independent patent claim 1. The invention further relates to a computer program, a device, a graphic display element for a vehicle and a vehicle.

[0003] A system for inductive energy transfer typically comprises a stationary induction charging device and a mobile induction charging device. During charging, an energy coil of one of the induction charging devices acts as the primary coil, and the energy coil of the other induction charging device acts as the secondary coil. Such systems are typically used for inductive energy transfer to a mobile application (device), for example, a motor vehicle, wherein the mobile application comprises the mobile induction charging device. In mobile applications, the energy coil of the mobile induction charging device is usually the secondary coil during charging. For inductive energy transfer, the primary coil generates an alternating magnetic field, which induces a voltage in the secondary coil.To enable inductive energy transfer and, in particular, to increase the efficiency of inductive energy transfer, the primary and secondary coils, and thus the energy coils of the inductive charging devices, must be positioned as precisely as possible relative to each other. For this purpose, the inductive energy transfer system can be equipped with a corresponding positioning device.

[0004] From US10541551 B2 it is known to calculate a vehicle movement value based on a vehicle speed.

[0005] To assist a driver in aligning the mobile inductive charging device relative to the stationary inductive charging device when parking, the relative position of the mobile inductive charging device can be displayed to the driver. The driver can then correct the position of the vehicle or park the vehicle based on the displayed position. However, it has been shown that drivers sometimes still have difficulties parking. For example, drivers often need several attempts until the vehicle is parked as desired. Furthermore, it has been shown that the achieved parking accuracy in autonomously controlled vehicles is not sufficient for the desired parking accuracy with regard to the positioning and alignment of the inductive charging devices.

[0006] The present invention is concerned with the object of providing improved or at least alternative embodiments for a method, a computer program, a device and a graphic display element for positioning a vehicle of the type mentioned at the outset, as well as for the vehicle.

[0007] According to a first aspect, a method for positioning a vehicle with a mobile inductive charging device in a defined position relative to a stationary inductive charging device according to claim 1 is proposed to achieve the object, wherein a positioning signal generated in one of the two inductive charging devices induces at least one voltage signal in the other of the two inductive charging devices, a relative distance between the mobile inductive charging device and the stationary inductive charging device is approximated from the at least one induced voltage signal, and a directional deviation of the vehicle from a desired direction with respect to the stationary inductive charging device is determined using a parking space detection sensor.

[0008] According to a second aspect, a computer program is proposed, wherein the computer program comprises program code means for causing a computer to carry out the steps of the method when the computer program is executed on the computer. According to a third aspect, a device with a mobile inductive charging device is proposed, wherein the device is designed such that a positioning signal generated in the stationary inductive charging device induces at least one voltage signal in the mobile inductive charging device, a relative distance between the mobile inductive charging device and the stationary inductive charging device is approximated from the at least one induced voltage signal, and a directional deviation of the vehicle from a desired direction is determined using a parking space detection sensor.

[0009] According to a fourth aspect, a graphic display element for a vehicle with a mobile inductive charging device is proposed, wherein the graphic display element is designed to display a relative distance between the mobile inductive charging device and a stationary inductive charging device, in particular as a relative distance indicator, wherein the relative distance is determined by means of the method, and to display a directional deviation of the vehicle from a desired direction, wherein the directional deviation is determined according to the method.

[0010] According to a fifth aspect, a vehicle with the device and the graphic display element is proposed.

[0011] Preferred embodiments are set out in the dependent claims.

[0012] According to the invention, the relative distance and directional deviation of the vehicle can be determined. Based on the relative distance and directional deviation, the mobile inductive charging device can be easily positioned relative to the stationary inductive charging device in a defined (specified) position and easily aligned in a defined (specified) orientation. This can be particularly advantageous when parking requires rotation about an axis transverse, in particular orthogonal, to the parking area. The relative distance and directional deviation can be determined using different sensors (with different operating principles) and, moreover, independently of one another. The sensors can differ in terms of accuracy and sensitivity with regard to distance (e.g. threshold for the distance above which a determination of the desired value is possible).

[0013] The relative distance is approximated based on at least one induced voltage signal. This is based on the principle that a changing magnetic field (e.g., a coil) induces a voltage. The inductive charging device can therefore function as a type of sensor.

[0014] The directional deviation from the target direction relative to the stationary inductive charging device is determined using the parking space detection sensor. The directional deviation characterizes a deviation in the orientation of the vehicle (e.g., a longitudinal axis or transverse axis of the vehicle) relative to the stationary inductive charging device. The directional deviation can also be determined using multiple parking space sensors.

[0015] The directional deviation determined in this way can make it possible to control (i.e., correct or maintain) the vehicle's alignment early on (i.e., while the distance is still relatively large). This can result in faster parking. This can apply to both a (human) driver and an autonomous vehicle control system. Furthermore, the directional deviation determined using the parking sensor can enable more precise vehicle alignment than a directional deviation determined, for example, using an inductive coil.

[0016] The display element supports the driver through constantly guided human-machine interaction in the task of positioning and aligning the vehicle with the desired accuracy relative to the stationary inductive charging device. The driver can steer the vehicle according to the displayed relative distance and the displayed directional deviation. This can assist the driver in parking precisely in one attempt, or at least with as few attempts as possible. For this purpose, the driver can be supported early on in achieving a precise alignment of the vehicle. This can make it easier for a user (i.e., the driver) to park the vehicle in the desired position and orientation.

[0017] The term "parking space detection sensor" refers to a sensor (particularly of the vehicle) that can detect features of the parking space. The parking space detection sensor can be located in or on the vehicle. For example, the parking space detection sensor is a camera located on the front or rear of the vehicle. The parking space detection sensor can be located, for example, on the vehicle's mobile inductive charging device (VA).

[0018] Preferably, the parking space detection sensor is designed to detect a parameter that characterizes a parallelism of the vehicle, in particular a parallelism of the vehicle relative to (with respect to) a neighboring vehicle, one or more features of a parking area or the surroundings, and / or one or more features of the stationary charging unit or a neighboring stationary charging unit. Based on the parameter that characterizes the parallelism of the vehicle, an optimal trajectory can be determined. The optimal trajectory corresponds to a route along which the vehicle should optimally move in order to park the vehicle appropriately. The optimal trajectory can be displayed to the user on the graphic display element, for example, together with the (steering wheel angle) trajectory corresponding to the current steering wheel angle.This can help the user to select the steering angle so that the vehicle can be parked with the optimal trajectory.

[0019] A (steering wheel angle) trajectory refers, in particular, to a path along which the vehicle will move if the vehicle is moved while maintaining the corresponding steering wheel angle. Various optional embodiments are explained below, which can relate equally to the method, the computer program, the device, the graphic display element, and the vehicle.

[0020] According to one embodiment, the directional deviation is a directional deviation angle, wherein a target-actual comparison of a steering wheel angle is created as a function of the directional deviation angle, wherein the steering wheel angle is an angle between steerable wheels of the vehicle and a vehicle longitudinal axis.

[0021] Based on the target-actual comparison, it can be determined whether the current steering angle is too large, too small or should be maintained in order to achieve the desired alignment of the vehicle.

[0022] According to another embodiment, in order to determine the directional deviation of the vehicle, the parking space detection sensor detects one or more features of a parking area, in particular one or more marking lines, one or more walls, and / or one or more features of the stationary inductive charging unit, in particular a line and / or an edge of the stationary inductive charging unit.

[0023] Alternatively or additionally, the parking sensor can detect one or more features of a neighboring vehicle to determine the directional deviation of the vehicle.

[0024] The term "parking area" refers to an area where the vehicle can be parked. This includes not only the area of ​​the area where the vehicle is parked in the target position and orientation (and which the vehicle covers), but also the surrounding area of ​​the area where the vehicle could be parked.

[0025] The feature of the parking area can have a defined relationship to the stationary inductive charging device. For example, the stationary inductive charging device can be arranged in a predetermined position and orientation relative to the wall that borders the parking space on one side. The predetermined relationship between the feature and the stationary inductive charging device can be used to determine the directional deviation of the vehicle relative to the stationary inductive charging device.

[0026] A marking line is, for example, a boundary line between two adjacent parking spaces or an edge of the parking area.

[0027] A line of the stationary inductive charging device is, for example, a line (e.g. a marking strip) applied to the stationary inductive charging device (specifically as a marking) or a structural feature of the stationary inductive charging device.

[0028] According to a further embodiment, the parking space detection sensor detects the features optically and / or electronically.

[0029] For example, the parking detection sensor includes a camera, such as a forward or rear camera of the vehicle, and / or part of a lidar system. The camera can, for example, detect reflections from reflectors. Furthermore, the parking detection sensor can detect the features electronically, for example, using magnetic fields or electromagnetic waves.

[0030] Preferably, the features are processed by an electronic control unit (ECU), wherein the electronic control unit determines the target-actual comparison of the steering wheel angle based on the detected feature.

[0031] According to one embodiment, display information is generated and output, wherein the display information comprises the relative distance between the mobile inductive charging device and the stationary inductive charging device, and / or a directional deviation value determined from the at least one induced voltage signal between a vehicle longitudinal direction and a desired vehicle longitudinal direction, and / or the directional deviation of the vehicle from the desired direction determined using the parking sensor.

[0032] With the help of the display information, the driver of the vehicle can be supported in the task of parking quickly and accurately in the form of guided human-machine interaction.

[0033] The vehicle's directional deviation from the target direction as display information can, for example, have color information that depends on the target / actual comparison of the steering wheel angle. For example, the color information can be red if the actual steering wheel angle deviates too greatly from the target steering wheel angle, yellow for a medium deviation, and green for a small deviation. The color information can be assigned to a feature of the parking space. For example, using the output color information, two boundary lines of the parking space that demarcate the (target) parking space from immediately adjacent parking spaces can be displayed in red, yellow, or green, depending on the target / actual comparison of the steering wheel angle.

[0034] According to another embodiment, the display information is output acoustically, haptically, and / or graphically. The display information can, for example, comprise a tone or a sequence of tones, a vibration, or display information on a screen.

[0035] According to a further embodiment, the relative distance and / or the directional deviation value is output in a first screen area of ​​a graphic display device, and / or the directional deviation is output in a second screen area of ​​the graphic display device that differs from the first screen area. The relative distance or the directional deviation value and the directional deviation can be output in separate screen areas. This can assist the driver in controlling position and orientation simultaneously. Preferably, the directional deviation value (in addition to the target / actual comparison of the steering wheel angle) is output in the second screen area.

[0036] For example, the relative distance can be output in the first screen area, the directional deviation can be output in the second screen area, and the directional deviation value can be output in a third screen area that differs from the first screen area and the second screen area. Alternatively, for example, the relative distance can be output in the first screen area, and the directional deviation and the directional deviation value can be output in the second screen area.

[0037] Alternatively, the relative distance and the directional deviation may be output in the first screen area and the directional deviation value in the second screen area.

[0038] According to one embodiment, the positioning signal is a positioning signal generated in the stationary inductive charging device and the at least one voltage signal is induced in the mobile inductive charging device.

[0039] According to a preferred embodiment, the positioning signal is generated by means of a positioning signal winding with a winding axis in the vehicle longitudinal direction and / or a desired vehicle longitudinal direction.

[0040] According to another preferred embodiment, the relative distance is approximated based on a number of turns of the positioning signal winding and an electric current in the positioning signal winding.

[0041] According to one embodiment, the mobile inductive charging device or the stationary inductive charging device has a first sensor winding and a second sensor winding which are arranged symmetrically to a vehicle longitudinal direction and / or to a desired vehicle longitudinal direction, the positioning signal generates a first voltage signal in the first sensor winding and a second voltage signal in the second sensor winding, an approximate relative distance value is determined from a sum of the first voltage signal and the second voltage signal, and a directional deviation value between the vehicle longitudinal direction and the desired vehicle longitudinal direction is determined from a comparison of the first voltage signal with the second voltage signal.

[0042] According to a preferred embodiment, a polynomial of at least third degree is used in the calculation of the approximated relative distance value.

[0043] According to another preferred embodiment, the first voltage signal and the second voltage signal are converted into digital signals and processed such that the first voltage signal and the second voltage signal are used only in a specific frequency range for determining the sum and comparing.

[0044] According to one embodiment, the positioning signal induces a first voltage signal and a second voltage signal, and the approximation of the relative distance includes calculating an approximated relative distance value from a sum of the first voltage signal and the second voltage signal, wherein there is a non-linear relationship between the sum and the distance value, and the approximated relative distance value is smaller the larger the sum of the first voltage signal and the second voltage signal is.

[0045] According to a preferred embodiment, the sum of the first voltage signal and the second voltage signal is evaluated for approximating the relative distance only if the sum exceeds a first threshold value and does not exceed a second threshold value.

[0046] The sum is therefore only taken into account in the approximation of the relative distance if the value of the sum is within a certain interval.

[0047] According to one embodiment, the method comprises the steps:

[0048] Generating a control signal for controlling the vehicle based on the determined directional deviation of the vehicle, and

[0049] Controlling the vehicle's steering with the generated control signal.

[0050] The control signal can be used to control an autonomously controlled vehicle to park the vehicle as desired.

[0051] According to a preferred embodiment, the display device has a screen which is designed to display the relative distance in a first screen area and to display the directional deviation of the vehicle in a second screen area which is different from the first screen area.

[0052] The term "inductive charging device" refers here to only one of at least two components required for energy transfer during an inductive charging process. During the inductive charging process, a power transfer coil generates an alternating magnetic field during the energy transfer in an inductive charging device. This alternating magnetic field induces a voltage in another power transfer coil of another inductive charging device. This additional inductive charging device thus serves as a counterpart for this specific charging process. The energy is transmitted wirelessly and absorbed by induction of a voltage.

[0053] A stationary inductive charging device is the non-mobile part of a vehicle charging system, i.e., the part that does not move with the vehicle. A stationary inductive charging device can preferably be located on, at, or in a floor. This can be an inductive charging device mounted on the ground or an inductive charging device sunk into a subsurface or into the ground. A floor can be a roadway, a parking lot surface, a garage floor, a floor in a parking garage, or another building. Alternatively, a stationary inductive charging device can also be located on walls or similar surfaces.

[0054] A mobile inductive charging device can be installed on and / or in a vehicle. Generally speaking, this refers to the part of a vehicle charging system that moves with the vehicle. An inductive charging device on and / or in the vehicle is therefore suitable for absorbing the magnetic field and supplying electrical energy to a vehicle's energy storage device, for example, a battery or accumulator in the vehicle.

[0055] For efficient energy transfer, the mobile inductive charging device must be positioned as precisely as possible in relation to the stationary inductive charging device. The mobile inductive charging device must therefore be positioned in a defined position in relation to a stationary inductive charging device. The defined position is a predetermined position which preferably takes into account that energy transfer can take place with the highest possible efficiency. In particular, it can be taken into account that one energy transfer winding in each of the two inductive charging devices is positioned opposite one another with the smallest possible distance from one another and with regard to an air gap between them. Since both energy transfer windings generally do not have to be the same size, symmetrical positioning in which the winding axes of the two energy transfer windings lie as close to one another as possible is also advantageous.Exact positioning is often difficult or, in extreme cases, even impossible for the driver without additional support in the form of a driver assistance system.

[0056] A positioning signal can be an alternating electromagnetic or magnetic field, which can induce a voltage signal in the other of the two inductive charging devices. It is possible that the positioning signal is transmitted or generated directly by a power transmission winding of an inductive charging device, or that one or more additional windings or another signal generation device is present for this purpose.

[0057] The positioning signal preferentially transmits power that is significantly lower than the power transmitted during energy transmission.

[0058] If a positioning signal is generated in the stationary inductive charging device, it induces a voltage in the mobile inductive charging device. If a positioning signal is generated in the mobile inductive charging device, it induces a voltage in the stationary inductive charging device.

[0059] The respective inductive charging device can be a larger unit, with the energy transfer components constituting only a part of the inductive charging device. The fact that a positioning signal is generated "in" an inductive charging device or that a voltage signal is generated "in" an inductive charging device means that this takes place within this larger unit.

[0060] During the positioning process, it is important for the driver of a vehicle to receive information about the relative distance to the target position. This allows the driver, for example, to gradually adjust the speed accordingly or prepare for braking.

[0061] A relative distance is a value that changes continuously, preferably proportionally with the distance, when the distance changes, but which does not necessarily provide information (e.g. information) about the absolute distance in meters. During a positioning process, it is sufficient for a driver to receive information about the relative distance to the target position, for example via a graphic display element. Information about the absolute distance is not necessary. While other relative methods are based on the comparison of several signals, this method uses the magnitude of an induced voltage to determine a relative distance. A relative distance is then approximated from the induced voltage. This means that the measured induced voltage is included in a calculation that is at least partially based on an approximation.This could, for example, be a polynomial approximation that approximates the nonlinear relationship between a voltage induced by an alternating magnetic field and the distance to the transmitter of the magnetic field. The approximate determination of the absolute distance in meters generally requires complex calibration. Combining an approximate calculation with a purely relative determination of the distance is advantageous, as this is a simple way to provide a driver with the necessary information without the need for complex calibration.

[0062] A parking space detection sensor is a receiving unit that can detect (necessary) parameters or features of the parking area using optical and / or electromagnetic sensors. The optical sensor detects, for example, parking space markings (e.g. a marking line that separates two parking spaces from each other), one or more walls that border or delimit the parking space (e.g. a pillar), and / or features of the stationary charging unit or a neighboring stationary charging unit such as an edge of the stationary inductive charging unit, a marking on the stationary inductive charging unit and / or the position of the stationary inductive charging unit. This transmits data relating to the parking area to the vehicle, which is required for positioning assistance, for example to display a further trajectory on a display of a parking assistant (e.g. the display element).The parking sensor can also comprise a system with multiple sensors. The sensors can be of the same type or different types. For example, it is not absolutely necessary to use only cameras. It would also be conceivable, for example, to combine a lidar system with radio receivers.

[0063] Preferably, the mobile inductive charging device or the stationary inductive charging device has a first sensor winding and a second sensor winding, which are arranged symmetrically to the vehicle longitudinal direction or to the desired vehicle longitudinal direction, and the positioning signal generates a first voltage signal in the first sensor winding and a second voltage signal in the second sensor winding, wherein an approximate relative distance value is determined (ascertained) from the sum of the two voltage signals and a directional deviation value between the vehicle longitudinal direction and the desired vehicle longitudinal direction is determined (ascertained) from the comparison of the two voltage signals to one another.

[0064] The first and / or the second sensor winding can be arranged in or near the mobile or stationary inductive charging device.

[0065] In general, a coil is defined here as a component for generating or receiving a magnetic field. A coil can consist of a winding and optionally other elements such as a magnetic core and a coil carrier. A winding is a wound arrangement of a current conductor. A winding can consist of one or more turns, with one turn representing one full circuit of a conductor. In general, however, a winding can also consist of fewer than one turn, for example, 0.5 turns. Of course, a partial number of turns, such as 2.5 turns, is also possible.

[0066] A sensor winding according to the invention can be designed in different forms and can have half, one, or preferably several turns. A conductor of such a sensor winding can, for example, have a cross-sectional area between 0.01 mm 2 and 2 mm 2A conductor can be designed as a stranded wire, as a single conductor, or in another form, for example in the form of conductor tracks on printed circuit boards.

[0067] If the sensor windings are located in a mobile inductive charging device, they are aligned symmetrically to the vehicle's longitudinal direction. If the sensor windings are located in a stationary inductive charging device, they are aligned symmetrically to the vehicle's desired longitudinal direction.

[0068] A stationary inductive charging device has a target vehicle longitudinal direction. This is a direction in which the longitudinal direction of the vehicle should be after successful positioning (i.e., in the desired orientation). A symmetrical arrangement of the two sensor windings to the vehicle longitudinal direction or to the target vehicle longitudinal direction means that the angle between the first sensor winding and the vehicle longitudinal direction / target vehicle longitudinal direction is at least approximately equal to the angle between the second sensor winding and the vehicle longitudinal direction / target vehicle longitudinal direction, wherein the two sensor windings are arranged axially symmetrically to the vehicle longitudinal direction / target vehicle longitudinal direction, mirrored. The symmetrical arrangement is advantageous because, in addition to the relative distance, a directional deviation can be determined by simply comparing the voltages induced in both sensor windings.The two sensor windings can, for example, be arranged at a 45° angle to the vehicle's longitudinal direction or to the desired vehicle's longitudinal direction. The positioning signal can be symmetrical to the vehicle's longitudinal direction or to the desired vehicle's longitudinal direction. In particular, the positioning signal can have a main direction of the magnetic field in the vehicle's longitudinal direction or in the desired vehicle's longitudinal direction.

[0069] Preferably, the positioning signal is generated by a positioning signal winding with a winding axis in the vehicle longitudinal direction or desired vehicle longitudinal direction.

[0070] If the positioning signal winding is located in a mobile inductive charging device of a vehicle, the winding axis of the positioning signal winding is advantageously aligned in the longitudinal direction of the vehicle.

[0071] If the positioning signal winding is located in a stationary inductive charging device, the winding axis of the positioning signal winding is advantageously aligned in the desired vehicle longitudinal direction.

[0072] Such an arrangement generates a magnetic field with a primary direction of the magnetic field lines in the longitudinal direction of the vehicle or in the desired longitudinal direction of the vehicle. This has the advantage that this design enables a significantly greater range for positioning than would be the case with a positioning signal generated by a power transmission winding with the same power or the same magnetic field strength. Furthermore, this orientation of the magnetic field is also particularly well suited to enabling the simplest possible detection of a positional or angular deviation in the sensor windings.

[0073] The positioning signal winding can be designed as a solenoid coil, also called a cylinder coil.

[0074] Particularly preferably, the positioning signal winding is designed such that the positioning signal winding has a particularly large extension in the travel plane and perpendicular to the longitudinal direction of the vehicle or to the desired vehicle longitudinal direction. For example, the positioning signal winding can extend over the entire width of an inductive charging device. Preferably, the positioning signal winding extends over at least 50% of the width of the energy transmission winding of the inductive charging device, particularly preferably over at least 75% of the width of the energy transmission winding of the inductive charging device. In particular, the positioning signal winding can also extend over the entire width of the energy transmission winding of the inductive charging device. This creates a largely homogeneous magnetic field with a main direction of the magnetic flux in the longitudinal direction of the vehicle orThe desired vehicle longitudinal direction is achieved and local field increases are prevented or reduced.

[0075] According to an advantageous embodiment, a parking space is optically detected by a parking space detection sensor. The image information is processed by an ECU, from which a target / actual comparison of the steering wheel angle is created as a function of a directional deviation angle.

[0076] A parking space is defined as an area containing the stationary inductive charging unit and within which the vehicle is to be parked. Parking spaces typically have side markings intended to delimit the parking area. By capturing the parking space from a perspective, a directional deviation angle can be determined (ascertained) based on image information.

[0077] The directional deviation angle describes the angle formed when the vehicle's longitudinal axis intersects the parking space boundary line. For optimal parking, the vehicle's longitudinal axis and the parking space boundary lines should be parallel.

[0078] The steering angle describes the angle between the steerable wheels and the vehicle's longitudinal axis. This angle is used to calculate the vehicle's trajectory. In some navigation displays or driver information systems, the trajectory is displayed graphically, thus providing the driver with assistance for optimal parking.

[0079] An ECU, or electronic control unit, is a microcontroller-based component used in various electronic systems to control, monitor, and regulate specific functions. The ECU is usually specifically designed for a particular application and contains electronic circuits, processors, memory, and interfaces. The main task of an ECU is to process input signals, analyze information, and generate corresponding output signals to achieve a desired behavior or function. This is done by executing pre-programmed algorithms and control logic implemented in the ECU. ECUs are used in a wide variety of applications, including engine control, fuel injection, transmission control, brake control, vehicle stability control, and driver assistance systems.However, ECUs are also used in other areas such as aerospace, medical technology, industrial automation and home appliances.

[0080] Preferably, the stationary inductive charging device is optically detected by the parking space detection sensor. This image information is processed by the ECU, resulting in a target / actual comparison of the steering angle as a function of the directional deviation angle.

[0081] The target / actual comparison allows the driver to be given an ideal steering angle, which ideally positions the vehicle within the given tolerances.

[0082] According to a further advantageous embodiment, at least one edge of the stationary inductive charging unit is optically detected by the parking space detection sensor. This image information is processed by the ECU, from which a target / actual comparison of the steering wheel angle is created as a function of a directional deviation angle.

[0083] The edges of the stationary inductive charging device can be used to calculate the relative rotation of the vehicle's longitudinal axis to the stationary inductive charging unit.

[0084] Another advantage is the electronic recording of the properties of the parking area via the parking space detection sensor, which are processed by the ECU, from which a target / actual comparison of the steering wheel angle is created depending on a directional deviation angle.

[0085] Electronic detection requires that the parking space detection sensor is a type of radio antenna and receives and processes data via this antenna near the stationary inductive charging device.

[0086] The relevant properties can include information about the parking area, its length and width. The relative coordinates of the stationary inductive charging device within the parking area are also conceivable. Further possibilities would be to transmit the directional information of the parking area using GPS data or a directional vector of the parking area or the edge of the stationary inductive charging device. Advantageously, the positioning signal is generated in the stationary inductive charging device, and the voltage signal is induced in the mobile inductive charging device.

[0087] In principle, both inductive charging devices – the stationary and the mobile inductive charging device – can be the inductive charging device in which the positioning signal is generated, and the other of the two inductive charging devices is then the inductive charging device in which the positioning signal is preferably detected by detecting at least one induced voltage signal. However, it can be advantageous to select the stationary inductive charging device as the inductive charging device in which the positioning signal is generated, and thus the mobile inductive charging device as the inductive charging device in which the voltage signal is detected. With this arrangement, the sensor data with the information about directional deviations and relative distances is located directly in the vehicle, which must then also make the appropriate travel correction.If the sensors are located in the stationary inductive charging device, information about a necessary driving correction must first be transmitted to the vehicle. This requires a separate data channel, and delays may occur.

[0088] The approximation expediently includes a calculation of an approximated relative distance value from the sum of the voltage signals, whereby the calculation assumes that there is a non-linear relationship between the sum of the voltage signals and the distance value and that the distance value is smaller the larger the sum of the voltage signals is.

[0089] While the voltage signals from the two sensor windings can be compared to determine a directional deviation, they can be added to determine a relative distance. The farther the two sensor windings are from the transmitter of the positioning signal, the lower the total voltage induced in the two sensor windings, all other parameters being equal. The relationship between distance and induced voltage is nonlinear.

[0090] According to a preferred embodiment, the approximated relative distance value is displayed graphically or acoustically in the vehicle.

[0091] The graphical or acoustic display of information about the relative distance to the target position can help the driver adjust their speed accordingly and / or prepare for braking. This can be done acoustically, for example, as is already common in parking assistance systems. The information can also be displayed graphically. A graphic display in the form of a bar that decreases as the vehicle approaches the target position may be suitable.

[0092] Particularly preferred is the directional deviation value displayed graphically in the vehicle.

[0093] It is particularly advantageous to display a directional deviation graphically, as a corresponding value is difficult to represent acoustically – perhaps even in addition to acoustic information about the relative distance. The directional deviation value can be represented, for example, in the form of an arrow pointing in the direction in which the driver must steer the vehicle. A corresponding graphical representation can be advantageously realized with a graphic representation of the relative distance – for example, in the form of a decreasing bar.

[0094] Advantageously, a value is calculated from at least the number of turns of the positioning signal winding and the electrical current in the positioning signal winding, and the value is used in the approximation of the relative distance.

[0095] A positioning signal winding through which alternating current flows generates a magnetic flux. This magnetic flux depends, among other parameters, significantly on the number of turns of the positioning signal winding and the electrical current. The effective value of the alternating electrical current is particularly relevant here. The geometry of the positioning signal winding is crucial for the other parameters. For a given frequency and a specific distance, the induced voltage is then proportional to the product of the number of turns and the current. A value calculated at least from the number of turns of the positioning signal winding and the electrical current—in particular, the product of the number of turns and the electrical current—can therefore be used to approximate the relative distance.

[0096] The voltage signals are conveniently converted into digital signals and processed in such a way that only the voltage signals in a specific frequency range are used to determine the sum and the comparison.

[0097] To convert them into digital voltage signals, the signals can be sampled in an analog-to-digital conversion unit. The digital voltage signals can then be transformed into the frequency domain and filtered within a specific frequency range.

[0098] In a frequency transformation, a signal is mathematically transformed from the time domain to the frequency domain. For a time-dependent signal, an evaluation in the frequency domain provides information about the strength of a specific frequency or frequency range in that signal. Evaluation in the frequency domain is advantageous here, especially since it makes it possible to filter the frequency or frequency range of the positioning signal, thus achieving a better signal-to-noise ratio and thus a greater range.

[0099] Alternatively, it may also be possible to evaluate the voltage signal in a specific frequency range or at a specific frequency without performing a mathematical transformation of the entire voltage signal.

[0100] It is preferred if the signal transformed into the frequency domain is filtered around the excitation frequency by a filter with a bandwidth B. The generated positioning signal is generated at a specific excitation frequency. The excitation frequency can be in the range of 10 kHz to 150 kHz and can, for example, correspond to a frequency according to SAE standard J2954 (Chapter 12).

[0101] It is not necessary to evaluate the entire induced voltage signal across the entire frequency range; an evaluation close to the excitation frequency is sufficient. A digital filter can be used for this.

[0102] A digital filter is a mathematical function applied to a discrete signal in the frequency domain. The discrete frequency values ​​are thus restricted to values ​​within a specific preset frequency band with a bandwidth B. The bandwidth can be on the order of 1 kHz, for example, and can correspond to a bandwidth according to SAE standard J2954. The frequency band is selected to contain the excitation frequency; preferably, it should be centered around the excitation frequency.

[0103] In a preferred variant, the calculation of the approximate relative distance value includes a polynomial that is at least a third-degree polynomial. The polynomial can, for example, have the following form:

[0104] / (x) = 0.0000159x 3 - 0.0116395x 2 + 2.9305376%

[0105] Where x can be the measured induced voltage, and f(x) is used to determine the relative distance. A corresponding polynomial is a simple way to approximate the nonlinear relationship between induced voltage and distance.

[0106] [unclaimed]

[0107] In an alternative preferred variant, the calculation of the approximated relative distance value contains an exponential function.

[0108] Preferably, the sum of the voltage signals is only evaluated if it exceeds a start value and as long as it does not exceed a stop value. The method for determining a relative distance is advantageous in addition to the determination of a directional deviation, which is based on a comparison of two induced voltages. For such a method, there can be a start value. If the total induced voltage is below this threshold, the signals are too weak to allow optimal evaluation. Furthermore, there can also be a stop value for the induced voltages. If the voltage exceeds this value, the method is no longer sufficiently accurate and the method is terminated. At short distances and thus high induced voltages, the magnetic field lines exhibit greater curvatures.Therefore, determining a directional deviation from a comparison of different induced voltages at different angles is no longer possible, or at least becomes more difficult, once the distance falls below a certain limit and the induced voltages exceed a certain limit. Beyond this limit and thus beyond this distance, a supplementary near-positioning system must take over.

[0109] The invention further relates to a graphic display element for a vehicle with a mobile inductive charging device, wherein the graphic display element is suitable for displaying a relative distance between a mobile inductive charging device and a stationary inductive charging device as a relative distance indicator and wherein the relative distance is determined by means of a method according to the invention.

[0110] The graphic display element can be a display. The method according to the invention, together with the display element, represents a driver assistance system that supports a driver in precisely positioning themselves in a defined position relative to a stationary inductive charging device. A relative distance indicator can be implemented, for example, in the form of a bar that decreases with the distance to the target position. It is also possible for the graphic display element to additionally visually indicate when the method according to the invention is terminated and for a supplementary proximity positioning method to be used. In addition to the relative distance, a directional deviation can be displayed, for example. A directional deviation can be implemented in the form of a pointer that points in the direction in which the vehicle must be steered.

[0111] Further examples of implementation are given below.

[0112] The present invention proposes a method for positioning a vehicle with a mobile inductive charging device in a defined position relative to a stationary inductive charging device, wherein a positioning signal is generated in one of the two inductive charging devices and the positioning signal induces at least one voltage signal in the other of the two inductive charging devices and a relative distance between the mobile inductive charging device and the stationary inductive charging device is approximated from the induced voltage signal, and the mobile inductive charging device comprises a parking space detection sensor.

[0113] The present invention makes it possible to perform this task with very high accuracy and under all environmental conditions. Furthermore, a display that includes all information is possible without the driver having to change their view.

[0114] The object of the invention is achieved. It can be achieved by combining the coil position center from front axle to rear axle (Mahle PD), steering angle, and rear axle detection (especially the alignment and thus the rotation of the vehicle).

[0115] In premium vehicles, it is interesting to give the driver information early enough so that he or she can set the correct steering angle in advance in order to park in such a way that the vehicle is aligned for inductive charging in the first move.

[0116] This demand also stems from autonomous driving / automated parking. The standard specifies a parking accuracy of +-10cm for autonomous vehicles, which is too low for wireless charging. For some premium vehicles, OEMs often require WPT positioning with xy and rotation angles within 5-100mm (user interfaces (HMIs) often require precisely this data), preferably with very high accuracies in the range of up to 10mm under all environmental conditions.

[0117] This requirement is difficult to fulfill because it is technically almost impossible to represent the y coordinate with sufficient accuracy - no matter what method is used.

[0118] This is one reason why there hasn't been an interoperable solution for positioning in WPT standards for 10 years that can achieve consensus. Furthermore, the requirements for an interoperable solution for WPT positioning are very high.

[0119] The MAHLE PD System (DIPS) is designed for budget, mid-range, and premium vehicles. If someone needs additional functions, for example, in a premium car, all the signals of the Mahle PD process can be used and the new function can be added to them.

[0120] The MAHLE PD system (DIPS) meets all the requirements of the standardization for an interoperable process, but does not meet the requirement to provide xy and rotation angle information to the HMI (a requirement of select premium vehicles). The real reason for this is the desire for a trajectory that allows the vehicle to be aligned to the GA with (almost) 100% probability by steering angle.

[0121] The task is to support drivers by using a PD system and other components already present in the vehicle (at little or no additional cost) to obtain information on how to align the vehicle with (almost) 100% probability in the first move so that wireless charging power transfer can take place, so that the technically impossible requirement of xy coordinates (at 5-10m, robust against all environmental influences, and with an accuracy of 10mm) can be dropped. Therefore, the mahle PD system should be further developed so that it meets the actual trajectory requirement. Furthermore, it should be possible to eliminate the need for xy and rotation angle coordinates for autonomous parking functions.

[0122] The Mahle PD system meets all requirements regarding accuracy, robustness, and range, but eliminates the y coordinate (in front of the GA pad) by optimizing the process for relative approximation. A decrementing bar indicates the x direction and an arrow rotates for the steering movement.

[0123] Method for positioning a vehicle with a mobile inductive charging device in a defined position relative to a stationary inductive charging device, wherein a positioning signal is generated in one of the two inductive charging devices and the positioning signal induces at least one voltage signal in the other of the two inductive charging devices, a relative distance between the mobile inductive charging device and the stationary inductive charging device is approximated from the induced voltage signal, the mobile inductive charging device comprises a parking space detection sensor.

[0124] Method, wherein the mobile inductive charging device or the stationary inductive charging device has a first sensor winding and a second sensor winding arranged symmetrically to the vehicle's longitudinal direction or to the desired vehicle's longitudinal direction, the positioning signal generates a first voltage signal in the first sensor winding and a second voltage signal in the second sensor winding, an approximate relative distance value is determined from the sum of the two voltage signals, and a directional deviation value between the vehicle's longitudinal direction and the desired vehicle's longitudinal direction is determined from the comparison of the two voltage signals. Method, wherein the positioning signal is generated by a positioning signal winding with a winding axis in the vehicle's longitudinal direction or the desired vehicle's longitudinal direction.

[0125] Method in which the parking space detection sensor optically detects a parking area, this image information is processed by the ECU, from which a target / actual comparison of the steering wheel angle is created as a function of a directional deviation angle.

[0126] Method, wherein the parking space detection sensor optically detects the stationary inductive charging device, this image information is processed by the ECU, from which a target / actual comparison of the steering wheel angle is created as a function of the directional deviation angle.

[0127] Method, wherein at least one edge of the stationary inductive charging unit is detected by the optical detection of the stationary inductive charging unit.

[0128] Method in which the parking space detection sensor electronically detects the properties of the parking area, these properties are processed by the ECU, from which a target / actual comparison of the steering wheel angle is created as a function of the directional deviation angle.

[0129] Method according to one of the preceding claims, wherein the positioning signal is generated in the stationary inductive charging device and the voltage signal is induced in the mobile inductive charging device.

[0130] Method according to one of the preceding claims, wherein the approximation includes a calculation of an approximated relative distance value from the sum of the voltage signals, wherein the following applies to the calculation: there is a non-linear relationship between the sum of the voltage signals and the distance value, the distance value is smaller the larger the sum of the voltage signals is.

[0131] Method whereby the approximated relative distance value is displayed graphically or acoustically in the vehicle.

[0132] Method in which the directional deviation value is displayed graphically in the vehicle.

[0133] Method, wherein a value is calculated from at least the number of turns of the positioning signal winding (41) and the electrical current intensity in the positioning signal winding (41), and the value is used in the approximation of the relative distance.

[0134] Method in which the voltage signals are converted into digital signals and processed in such a way that only the voltage signals in a specific frequency range are used to determine the sum and the comparison.

[0135] Method wherein the calculation of the approximated relative distance value includes a polynomial which is a polynomial of at least third degree.

[0136] Method in which the sum of the voltage signals is only evaluated if it exceeds a start value and as long as it does not exceed a stop value.

[0137] A graphic display element for a vehicle with a mobile inductive charging device, wherein the graphic display element is suitable for displaying a relative distance between a mobile inductive charging device and a stationary inductive charging device as a relative distance indicator, and the relative distance is determined by the method. It is understood that the features mentioned above and those explained below can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the present invention.

[0138] The various optional embodiments which have been explained or will be explained herein and which relate to the method according to the invention relate in the same way to the computer program, device, graphic display element and vehicle according to the invention and vice versa.

[0139] Preferred embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description, wherein the same reference numerals refer to the same or similar or functionally identical components.

[0140] It shows, schematically:

[0141] Fig. 1 is a highly simplified representation of a vehicle with an inductive charging device,

[0142] Fig. 2 is a plan view of an inductive charging device with sensor windings,

[0143] Fig. 3 is a schematic representation of a vehicle charging system during

[0144] positioning process,

[0145] Fig. 4 shows a graphic display element of the directional deviation a) and four different displays of the relative distance b)-e),

[0146] Fig. 5 a highly simplified block diagram regarding the evaluation of the measured voltages

[0147] Fig. 6a shows a representation of the graphic display element according to an embodiment,

[0148] Fig. 6b is a further illustration of the graphic display element shown in Fig. 6a, Fig. 6c is a further illustration of the graphic display element shown in Fig. 6a,

[0149] Fig. 7 is a representation of the graphic display element according to another embodiment,

[0150] Fig. 8a a schematic representation of a parking situation,

[0151] Fig. 8b a schematic representation of another parking situation,

[0152] Fig. 9a a schematic representation of another parking situation,

[0153] Fig. 9b a schematic representation of yet another parking situation,

[0154] Fig. 10a a schematic representation of another parking situation,

[0155] Fig. 10b a schematic representation of another parking situation,

[0156] Fig. 11 is a representation of the graphic display element according to an embodiment of the present invention,

[0157] Fig. 12a shows a representation of the graphic display element according to an embodiment of the present invention,

[0158] Fig. 12b shows another representation of the graphic display element according to an embodiment of the present invention,

[0159] Fig. 12c shows a further illustration of the graphic display element according to an embodiment of the present invention,

[0160] Fig. 13 is a representation of the graphic display element according to an embodiment of the present invention,

[0161] Fig. 14 is a representation of the graphic display element according to an embodiment of the present invention,

[0162] Fig. 15 is a diagram of the graphic display element according to another embodiment of the present invention,

[0163] Fig. 16 is a representation of the graphic display element according to another embodiment of the present invention,

[0164] Fig. 17a is a representation of the graphic display element according to another embodiment of the present invention,

[0165] Fig. 17b is a representation of the display element shown in Fig. 18a,

[0166] Fig. 18a shows a representation of the graphic display element according to another

[0167] Embodiment of the present invention,

[0168] Fig. 18b is a representation of the display element shown in Fig. 19a. Fig. 19a is a representation of a parking area according to an embodiment of the present invention,

[0169] Fig. 19b is a further illustration of the parking area according to the embodiment of the present invention shown in Fig. 20a,

[0170] Fig. 19c shows another representation of the parking area according to the embodiment of the present invention shown in Fig. 20a,

[0171] Fig. 20 is a representation of the parking area according to another embodiment of the present invention,

[0172] Fig. 21 is a representation of the display element according to an embodiment of the present invention, and

[0173] Fig. 22 is a diagram of the display element according to another embodiment of the present invention.

[0174] Fig. 1 shows a mobile inductive charging device 1, 1a, which is arranged on a vehicle 2 with a battery 3 and is spatially positioned above a stationary inductive charging device 1, 1b. During operation, energy can be transferred from the stationary inductive charging device 1b to the mobile inductive charging device 1a, thus charging the battery 3. The mobile inductive charging device 1a and the stationary inductive charging device 1b together form or are part of the vehicle charging system 8. Energy can be temporarily transferred from the mobile inductive charging device 1a to the stationary inductive charging device 1b.

[0175] The stationary inductive charging device 1b arranged on the ground in Fig. 1 can alternatively be recessed into the roadway (not shown here). In a recessed arrangement, the inductive charging device 1b can be covered by certain layers of the roadway or be flush with the road surface.

[0176] Fig. 2 shows a plan view of an inductive charging device 1 according to the invention. This can be a mobile inductive charging device 1a or a stationary inductive charging device 1b. In the present exemplary embodiment, eight flux guiding elements 5 are shown, which are arranged radially in the plane around the center 7 of the energy transmission winding 4. The energy transmission winding 4, which is arranged below the flux guiding elements 5 with respect to this plan view, is indicated by dashed lines. The energy transmission winding 4 is a flat coil 10 here. A first sensor winding 9a is arranged around one of the flux guiding elements 5 and a second sensor winding 9b is arranged around another flux guiding element 5. The sensor windings are designed here as cylindrical coils. The first sensor winding 9a is arranged axially symmetrically to the second sensor winding 9b with respect to the vehicle longitudinal direction 6.The first sensor winding 9a has a first radial longitudinal direction 11a and the second sensor winding 9b has a second radial longitudinal direction 11b. The angle 32 between the first radial longitudinal direction 11a and the vehicle longitudinal direction 6 is at least approximately the same size as the angle 34 between the second radial longitudinal direction 11b and the longitudinal direction of the vehicle. The first radial longitudinal direction 11a and the second radial longitudinal direction 11b intersect or cross at least approximately in the center 7 of the energy transmission winding 4. The first radial longitudinal direction 11a and the second radial longitudinal direction 11b run radially outwards from the center 7 of the energy transmission winding 4. The two sensor windings 9a, 9b are arranged symmetrically to the vehicle longitudinal direction 6.

[0177] During the charging process, the vehicle 2 is positioned above the stationary inductive charging device 1b and energy is transferred to the mobile inductive charging device 1a or from the mobile inductive charging device 1a to the stationary inductive charging device 1b. The flux guiding elements 5 assume the function of guiding the magnetic field. In the charging state, the field lines of the magnetic field run approximately radially in them. Three magnetic field lines 35 are symbolically indicated in Fig. 2. Since the first radial longitudinal direction 11a and the second radial longitudinal direction 11b are also aligned radially and thus at least approximately parallel to the magnetic field lines 35, only relatively little or no voltage is induced in the first sensor winding 9a and the second sensor winding 9b.This is important because the high power levels of the energy transfer could otherwise easily lead to the sensor windings being destroyed. Fig. 3a shows a vehicle 2 with a vehicle longitudinal direction 6 with a mobile inductive charging device 1a during a positioning process above a stationary inductive charging device 1b with a desired vehicle longitudinal direction 6a. The vehicle 2 drives directly towards the stationary inductive charging device 1b and the desired vehicle longitudinal direction 6a is thus the same as the longitudinal direction of the vehicle 6. In addition to the energy transfer winding (not shown), the mobile inductive charging device 1a also contains a positioning signal winding 41. The positioning signal winding 41 has a winding axis 36 and a radial longitudinal direction 11. The stationary inductive charging device 1b has two sensor windings 9a and 9b in addition to the energy transfer winding (not shown). In contrast to the embodiment in Fig.2, the two sensor windings 9a and 9b have a greater extension here and intersect in the center of the inductive charging device 1. Both sensor windings 9a and 9b each have a radial longitudinal direction 11a and 11b. Both sensor windings 9a and 9b are arranged symmetrically to the desired vehicle longitudinal direction 6a. This arrangement of the windings is particularly advantageous for positioning. The positioning signal winding 41 generates a positioning signal (not shown) which can induce a voltage in the sensor windings 9a and 9b. The positioning signal winding 41 generates a fairly homogeneous magnetic field. A voltage is induced in the sensor windings 9a and 9b by the magnetic field of the positioning signal winding 41. If the vehicle drives exactly perpendicularly towards the stationary inductive charging device 1b, as shown in Fig. 3a, an equal voltage is induced in both sensor windings 9a and 9b.

[0178] Fig. 3b shows an embodiment in which the positioning signal winding 41 is arranged in the stationary inductive charging device 1b and the sensor windings 9a and 9b are arranged in the mobile inductive charging device 1a. The functioning of this embodiment is otherwise exactly the same. Shown here is a case in which the vehicle 2 does not drive perpendicularly towards the stationary inductive charging device 1b, but deviates from it at an angle of approximately 45°. The vehicle's longitudinal direction 6 and the connecting line between the stationary inductive charging device 1b and the mobile inductive charging device 1a are thus at a directional deviation angle 39 of 45°. In this case, the positioning signal winding 41 generates a magnetic field which is perpendicular to the first sensor winding 9a. Here, a maximum voltage is induced.The magnetic field generated by the positioning signal winding 41 is also approximately parallel to the second sensor winding 9b. Minimal or no voltage is induced here.

[0179] In both embodiments Fig. 3a and 3b, in addition to determining a directional deviation value by comparing the voltages induced in the two sensor windings 9a and 9b, a distance value to the target position can be approximated from the sum of the voltages induced in the two sensor windings 9a and 9b.

[0180] Fig. 4a to Fig. 4e show a representation of a graphic display element 50 which displays the directional deviation (Fig. 4a) as well as the relative distance at four different distances (Fig. 4b to Fig. 4e). In Fig. 4a, an arrow is visible as the first directional deviation indicator 47 on a graphic display element 50. The graphic display element 50 is located in a vehicle. In Fig. 4b to Fig. 4e, a relative distance indicator 48 is shown in the form of a bar in a graphic display element 50 during an approach process. The bar slowly decreases from Fig. 4b via Fig. 4c and Fig. 4d to Fig. 4e as the vehicle approaches its target position. The graphic display element 50 also shows a near-positioning circle 49.As soon as the distance indicator 48, in the form of a bar, has degraded to the point where it is within the near-positioning circle 49, the positioning method being evaluated changes. Within the near-positioning circle 49, a so-called near-positioning method is evaluated. This provides (direct) information about a relative distance to the target position, but no longer provides a (direct) directional deviation value.

[0181] Fig. 5 shows a highly simplified block diagram of the evaluation of the measured voltages. The voltage signals 13a, 13b received in the two sensor signal windings 9a, 9b are both processed in a comparison unit COMP and a summation unit SUM. The comparison unit COMP compares the two voltage signals 13a, 13b with each other and determines a directional deviation value 17. This directional deviation value is displayed in a graphic display element 50 as the first directional deviation indicator 47 in the form of an arrow. The summation unit SUM adds the two voltage signals 13a, 13b; the result 43 is displayed in a graphic display element 50 as a relative distance indicator 48 in the form of a bar.A CHECK test unit checks whether the sum of the voltage signals 13a, 13b is above a start value (first threshold value) of the voltage signals 45 and below a stop value (second threshold value) of the voltage signals 46. Only if both are the case is the result displayed in the graphic display element 50. The graphic display element 50 also contains a near-positioning circle 49. If the sum of the voltage signals 13a, 13b corresponds to the stop value of the voltage signals 46, the graphic display element 50 shows the relative distance indicator 48 in the form of a bar precisely on the near-positioning circle 49. If the sum of the voltage signals 13a, 13b is greater than the stop value of the voltage signals 46, the positioning method according to the invention is no longer evaluated for the graphic display element 50. Another near positioning method is now evaluated and displayed on the graphic display element 50.

[0182] Fig. 6a to Fig. 6c show the graphic display element according to one embodiment. The graphic display element 50 displays the first directional deviation indicator 47, the relative distance indicator 48, and the near positioning circle 49, as in the embodiment shown in Figs. 4a to 4e. Unlike the previous embodiment, the first directional deviation indicator 47 and the relative distance indicator 48 are not displayed independently of each other, but are combined into a common indicator.

[0183] The orientation of the arrow depends on the directional deviation value 17, which is determined by comparing the voltage signals 13a, 13b. The arrowhead points from the mobile inductive charging device 1a (also referred to as vehicle assembly VA) to the stationary inductive charging device (also referred to as ground assembly GA), i.e., in the direction in which the vehicle is to be moved. The size or length of the relative distance indicator 48 depends on the approximate relative distance (optionally, the size of the directional deviation indicator 47 can also depend on the approximate relative distance). The relative distance is visualized by means of a decreasing bar. As shown in Fig. 6c, the distance indicator 48 can be displayed separately for two orthogonal directions (here, the x and y directions), particularly when positioning in the near-positioning circle 49.The directional deviation value 17 can be output or displayed by means of the two distance indicators 48, which are orthogonal to each other.

[0184] The Mahle PD process (DIPS) can be represented with surfaces as shown in Fig. 6a to Fig. 6c. A decreasing bar indicates the x-direction, and the rotation (i.e., orientation) of an arrow indicates the steering movement. The arrow points from the mobile inductive charging device (VA) 1a to the stationary inductive charging device (GA) 1b. The driver is responsible for ensuring parallelism (i.e., correct alignment in the parking space).

[0185] Fig. 7 shows the graphic display element 50 according to another embodiment. Unlike the embodiment shown in Figs. 6a to 6c, the first directional deviation indicator 47 and the relative distance indicator 48 are displayed independently of each other.

[0186] The orientation of the first directional deviation indicator 47 (here orientation of an arrowhead) shows the directional deviation value 17. The size of the relative distance indicator 48 shows the (approximate) relative distance.

[0187] Figs. 8a, 8b, 9a, 9b, 10a, and 10b show various parking situations in which vehicle 2 is parked with a rotation around the z-axis (axis orthogonal to the image plane). As can be seen in Figs. 8a and 8b, the driver himself must ensure the parallelism of vehicle 2 (i.e., alignment in the parking space).

[0188] Fig. 9a and Fig. 9b show the vehicle 2 in different orientations relative to the stationary inductive charging device 1b and the wall 54. The first directional deviation indicator 47, which indicates the directional deviation value 17, points in the same direction in both cases shown in Fig. 9a and Fig. 9b.

[0189] This can lead to the driver parking vehicle 2 as shown in Fig. 10a and Fig. 10b. This may not be critical for energy transfer, as the coils are rotationally symmetrical. However, if the vehicle is to be parked as parallel to the parking space as possible (or aligned with the parking space) so that parking in neighboring spaces is not affected, sensors for parallelism (or alignment) are desirable, especially for autonomous driving. However, this would generally entail additional costs. Therefore, a solution with little or no additional costs is sought.

[0190] In (premium) vehicles, the following features are usually available anyway and do not entail any extra costs:

[0191] - Forward camera,

[0192] - Rear camera, and

[0193] - Display in the camera what the further trajectory is if you turn the same way as the steering wheel is.

[0194] However, no reference point for absolute coordinates can be obtained from the additional features mentioned. This requires a further step. Using image recognition (e.g., using a neural network), the GA (in particular, its orientation via the detection of side edges) can be detected. This determines the vehicle's rotation relative to the GA. Then, for example, the arrow can be incorporated into the camera image.

[0195] Figs. 11 and 12 show possible representations. The representations apply analogously in 3D.

[0196] Fig. 11 shows the graphic display element 50 with a first screen area 52 and a second screen area 53. In the second screen area, a (steering wheel angle) trajectory 51 and another (steering wheel angle) trajectory 55 of the vehicle 2 can be output (steering angle), which can be dependent on the directional deviation determined using the parking space detection sensor 20. In the first screen area 52, a (virtual) view of the vehicle 2 from above is output.

[0197] A (steering wheel angle) trajectory refers in particular to a route along which the vehicle will move at the corresponding steering wheel angle.

[0198] For autonomous driving or automated parking, the difference between the arrow direction and the wheel turning trajectory can be determined. This value can also be useful for manual parking.

[0199] For manual parking, it may require (at least) the arrow pointing towards GA, optionally the steering angle trajectory.

[0200] Fig. 13 and Fig. 14a to 14c show the graphic display element according to an embodiment of the present invention.

[0201] Fig. 15 and Fig. 16 each show another embodiment of the graphic display element according to the present invention.

[0202] Figs. 17a and 17c show the graphic display element according to another embodiment of the present invention.

[0203] For a rough approximation, the steering angle trajectory is compared with the edges of the GA. If the steering angle is correct (within tolerances), it is highlighted with green lines; if not, with red lines. Additionally, the arrow from the center of the VA to the center of the GA can already be displayed (from Mahle PD).

[0204] Figs. 18a and 18b show the graphical display element according to another embodiment of the present invention. Optionally, the arrow can be displayed later, when the vehicle is further forward (i.e., closer to the stationary inductive charging device), to reduce distraction (for the driver). Figs. 19a to 19c show various representations of the parking area 22 according to an embodiment of the present invention. The representations can be output on the graphical display element 50, for example, in the second screen area 53 of the graphical display element 50.

[0205] Here, a steering angle is used with the parking guidelines 56 or garage wall 54, if present, as an additional or alternative comparison. The parking guidelines are attached to a wall.

[0206] Now there are two cases: (i) the autonomous vehicle 2 should control to this angle, or (ii) the manual driver needs detection of the deviation.

[0207] For a rough approximation, the steering angle trajectory is compared with the edges of the GA (or the garage wall or parking space lines / parking guidelines, if present). If the steering angle is appropriate (within tolerances), this is highlighted with green lines, for example; if not, with red lines and an intermediate yellow line. This allows for a more accurate approximation of the GA.

[0208] Fig. 20 shows a representation of a parking area 22 according to an embodiment of the present invention. The representation can be output on the graphic display element 50, for example, in the second screen area 53 of the graphic display element 50.

[0209] Here, the target-actual comparison of the steering angle is compared with the straight edge of the GA (stationary inductive charging device 1 b).

[0210] Fig. 21 shows a representation of the display element according to an embodiment of the present invention. Fig. 22 shows a split screen. One side shows the original DIPS method (optionally with a top view of the car). The other side shows the GA, line, and / or garage wall. Detection is performed by a camera (parking space detection sensor 20).

[0211] Fig. 22 shows a representation of the display element according to another embodiment of the present invention. Here, the DIPS direction arrow is still drawn into the camera (the camera image).

[0212] It is understood that the exemplary embodiments shown in the figures merely represent exemplary embodiments of the method according to the invention and the graphic display device according to the invention, which are intended to illustrate the advantages of the method according to the invention and the graphic display device according to the invention. Various modifications can be made to these exemplary embodiments without departing from the scope of the present invention.

[0213] Reference symbol

[0214] 1 inductive charging device

[0215] 1a mobile inductive charging device

[0216] 1 b stationary inductive charging device

[0217] 2 vehicles

[0218] 3 Vehicle energy storage

[0219] 4 Energy transmission winding

[0220] 5 Flow guide element

[0221] 6 Vehicle longitudinal direction

[0222] 6a Target vehicle longitudinal direction

[0223] 7 Center of the energy transmission winding

[0224] 8 Vehicle charging system

[0225] 9 Sensor winding

[0226] 9a first sensor winding

[0227] 9b second sensor winding

[0228] 10 flat coil

[0229] 11 radial longitudinal direction

[0230] 11a first radial longitudinal direction

[0231] 11 b second radial longitudinal direction

[0232] 13 Voltage signal

[0233] 13a first voltage signal

[0234] 13b second voltage signal

[0235] 17 Directional deviation value

[0236] 20 parking space detection sensor

[0237] 21 ECU

[0238] 22 parking spaces

[0239] 23 edge

[0240] 24 steering angle

[0241] 32 Gap between flow guide elements

[0242] 33 first angle

[0243] 34 second angle 35 magnetic field line

[0244] 36 Winding axis

[0245] 39 Directional deviation angle

[0246] 41 Positioning signal winding

[0247] 43 Sum of voltage signals

[0248] 44 Approximate relative distance value

[0249] 45 Starting value of the voltage signals (first threshold)

[0250] 46 Stop value of the voltage signals (second threshold)

[0251] 47 first direction deviation indicator

[0252] 48 Relative distance indicators

[0253] 49 Near positioning circle

[0254] 50 graphic display element

[0255] 51 Steering wheel angle trajectory

[0256] 52 first screen area

[0257] 53 second screen area

[0258] 54 Wall

[0259] 55 additional steering wheel trajectories

[0260] 56 Parking Guideline

[0261] COMP comparison unit

[0262] SUM summation unit

[0263] CHECK test unit

Claims

Patent claims 1. A method for positioning a vehicle (2) with a mobile inductive charging device (1a) in a defined position relative to a stationary inductive charging device (1b), wherein - a positioning signal generated in one of the two inductive charging devices (1a, 1b) induces at least one voltage signal (13a, 13b) in the other of the two inductive charging devices (1a, 1b), - a relative distance between the mobile inductive charging device (1a) and the stationary inductive charging device (1b) is approximated from the at least one induced voltage signal (13a, 13b), and - using a parking space detection sensor (20), a directional deviation of the vehicle (2) from a desired direction with respect to the stationary inductive charging device (1 b) is determined.

2. Method according to claim 1, wherein the directional deviation is a directional deviation angle (39), wherein a target-actual comparison of a steering wheel angle (24) is created as a function of the directional deviation angle (39), wherein the steering wheel angle is an angle between steerable wheels of the vehicle (2) and a vehicle longitudinal axis.

3. Method according to one of the preceding claims, wherein, in order to determine the directional deviation of the vehicle (2), the parking space detection sensor detects one or more features of a parking area, in particular one or more marking lines, one or more walls, one or more features of an adjacent vehicle and / or one or more features of the stationary inductive charging unit (1b), in particular a line and / or an edge of the stationary inductive charging unit (1b).

4. The method according to claim 3, wherein the parking space detection sensor (20) detects the features optically and / or electronically.

5. Method according to one of the preceding claims, wherein display information is generated and output, wherein the display information comprises the relative distance between the mobile inductive charging device (1 a) and the stationary inductive charging device (1 b), and / or a directional deviation value (17) determined from the at least one induced voltage signal (13a, 13b) between a vehicle longitudinal direction (6) and a desired vehicle longitudinal direction (6a), and / or the directional deviation of the vehicle (2) from the desired direction determined using the parking space sensor (20).

6. The method according to claim 5, wherein the display information is output acoustically, haptically and / or graphically.

7. The method according to claim 5, wherein the relative distance and / or the directional deviation value (17) is output in a first screen area (52) of a graphic display device (50), and / or the directional deviation is output in a second screen area (53) of the graphic display device (50) that is different from the first screen area (52).

8. Method according to one of the preceding claims, wherein the positioning signal is a positioning signal generated in the stationary inductive charging device (1b) and the at least one voltage signal (13a, 13b) is induced in the mobile inductive charging device (1a).

9. Method according to one of the preceding claims, wherein the mobile inductive charging device (1 a) or the stationary inductive charging device (1 b) comprises a first sensor winding (9a) and a second Sensor windings (9b) which are arranged symmetrically to a vehicle longitudinal direction (6) and / or to a desired vehicle longitudinal direction (6a), the positioning signal generates a first voltage signal (13a) in the first sensor winding (9a) and a second voltage signal (13b) in the second sensor winding (9b), an approximate relative distance value (44) is determined from a sum (43) of the first voltage signal (13a) and the second voltage signal (13b), and a directional deviation value (17) between the vehicle longitudinal direction (6) and the desired vehicle longitudinal direction (6a) is determined from a comparison of the first voltage signal (13a) with the second voltage signal (13b).

10. Method according to one of the preceding claims, wherein the positioning signal induces a first voltage signal (13a) and a second voltage signal (13b) and the approximation includes a calculation of an approximated relative distance value (44) from a sum (43) of the first voltage signal (13a) and the second voltage signal (13b), wherein there is a non-linear relationship between the sum (43) and the distance value (44) and the approximated relative distance value (44) is smaller, the larger the sum (43) of the first voltage signal (13a) and the second voltage signal (13b) is. 11 . Method according to one of the preceding claims, comprising the steps Generating a control signal for controlling the vehicle (2) based on the determined directional deviation of the vehicle (2), and controlling a steering of the vehicle (2) with the generated control signal.

12. A computer program comprising program code means for causing a computer to carry out the steps of a method claimed in any one of claims 1 to 11 procedure when the computer program is executed on the computer.

13. Device with a mobile inductive charging device (1a), wherein the device is designed such that a positioning signal generated in the stationary inductive charging device (1b) induces at least one voltage signal (13a, 13b) in the mobile inductive charging device (1a), from the at least one induced voltage signal (13a, 13b) a relative distance between the mobile inductive charging device (1a) and the stationary inductive charging device (1b) is approximated, and a directional deviation of the vehicle (2) from a desired direction is determined using a parking space detection sensor (20).

14. Graphic display element (50) for a vehicle (2) with a mobile inductive charging device (1a), wherein the graphic display element (50) is designed to display a relative distance between the mobile inductive charging device (1a) and a stationary inductive charging device (1b), in particular as a relative distance indicator (48), wherein the relative distance is determined by means of a method according to one of claims 1 to 11, and to display a directional deviation of the vehicle (2) from a desired direction, wherein the directional deviation is determined by a method according to claims 1 to 11.

15. Vehicle (2) with a device according to claim 13 and a graphic display element according to claim 14.

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