Method for operating an inductive energy transfer system

Abstract

The present invention relates to a method for operating a system (1) for inductive energy transfer with a stationary inductive charging device (2, 2a) and a mobile inductive charging device (2, 2b). One of the induction charging devices (2) has a transmitting coil (7) wound around a predetermined winding axis (1), and the other induction charging device (2) has two receiving coils (9, 10), each with its own predetermined winding axis (A2, A3). The transmitting coil (7) generates a predetermined pulse signal (P), and the relative position of the induction charging devices (2) to each other is determined based on the voltages (U) induced in the receiving coils (9, 10) by the pulse signal (P). The invention also relates to a system operated in this manner (1).

Description

[0001] The present invention relates to methods for operating a system for inductive energy transmission, which comprises at least one stationary and at least one mobile inductive charging device. The invention also relates to a system operated in this manner.

[0002] For inductive energy transfer, a stationary induction charging device and a mobile induction charging device typically interact inductively within a system. The mobile induction charging device is typically arranged in an associated mobile application, for example, in a motor vehicle, to enable inductive energy transfer between the mobile application and the stationary induction charging device. For energy transfer, the respective induction charging device has an energy coil, whereby the energy coils couple to one another during charging operation for inductive energy transfer. This requires appropriate positioning of the energy coils relative to one another.

[0003] The present invention addresses the problem of providing improved or at least different embodiments of a method for operating a system of the type mentioned above, as well as of such a system. In particular, the present invention addresses the problem of providing embodiments of the method and the system that are characterized by simplified detection of the relative positions of the system's inductive charging devices.

[0004] This object is achieved according to the invention by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims.

[0005] The present invention is therefore based on the basic idea of ​​using a transmitting coil with a known winding axis in one of the inductively interacting induction charging devices in a system for inductive energy transmission and of generating a pulse signal of known polarity by means of the transmitting coil, wherein this pulse signal is received in the other induction charging device by means of two receiving coils, each of which has known but different winding axes, and of detecting a direction along which the receiving coil is offset from the transmitting coil and thus the induction charging devices are offset from one another based on the polarity of the respective voltage induced in the receiving coils due to the pulse signal.Thus, the receiving coils can not only detect that a transmitting coil and thus the associated inductive charging device are nearby, but also determine the offset of the transmitting coil and thus the associated inductive charging device relative to the receiving coils and thus to the inductive charging device associated with the receiving coils. This allows for a simple and reliable, precise detection of the relative position of the inductive charging devices and thus also enables precise relative positioning of the inductive charging devices. In addition to simplifying the positioning of the inductive charging devices relative to one another, this leads to increased efficiency in inductive energy transfer.

[0006] According to the inventive concept, the system has at least one stationary induction charging device and at least one mobile induction charging device. The respective mobile induction charging device is arranged in an associated mobile application, in particular in a motor vehicle. The respective induction charging device has a coil for inductive energy transmission, which is also referred to below as an energy coil. This means that the respective stationary induction charging device has a stationary energy coil and the respective mobile induction charging device has a mobile energy coil. The respective stationary induction charging device cooperates with one of the at least one mobile induction charging device during charging operation in order to inductively transmit energy using the energy coils.During charging, the inductively interacting induction charging devices are arranged opposite one another and spaced apart from one another in one direction, which is also referred to below as the first direction. A positioning device of the system serves to detect the relative position of the induction charging devices associated during charging. The positioning device has a transmitting device in one of the induction charging devices associated during charging and a receiving device in the other induction charging device. The transmitting device has a transmitting coil wound around a predetermined winding axis, which is also referred to below as the transmitting winding axis. The transmitting winding axis runs parallel to a second direction running transversely to the first direction. The receiving device has a receiver with a first receiving coil and a second receiving coil.The first receiving coil is wound around a predetermined winding axis, which is also referred to below as the first receiving winding axis. The second receiving coil is wound around a predetermined winding axis, which is also referred to below as the second receiving winding axis. The first receiving winding axis and the second receiving winding axis run transversely to the first direction. Furthermore, the first receiving winding axis and the second receiving winding axis run inclined or transversely to one another. To detect the relative position of the receiving device to the transmitting device and thus of the associated induction charging devices to one another, a predetermined pulse signal is generated with the transmitting coil. Voltages induced in the receiving coils are determined using the pulse signal. This means that a first voltage induced in the first transmitting coil by means of the pulse signal and a second voltage induced in the second transmitting coil by means of the pulse signal are determined.If both induced voltages have the same polarity, which is also referred to below as the first polarity, it is detected that the transmitting device is arranged in front of the receiving device along the transmitting winding axis. If both induced voltages have the same polarity and opposite polarity to the first polarity, also referred to below as the second polarity, it is detected that the transmitting device is arranged behind the receiving device along the transmitting winding axis. It is therefore detected that the transmitting device is arranged in front of the receiving device along the transmitting winding axis if the induced voltages both have the first polarity. Furthermore, it is detected that the transmitting device is arranged behind the receiving device along the transmitting winding axis if the induced voltages both have the second polarity.

[0007] In this case, a "given" winding axis is understood to mean one that is known in advance. Accordingly, the winding direction of the winding is also known. Thus, by knowing all winding directions, it is possible to determine the corresponding polarity of the induced voltage for a given pulse signal and thus, in the overall context, the direction of the distance between the receiver and the transmitter coil. This also makes it possible to determine the direction of the distance between the inductive charging devices that interact inductively with each other during charging.

[0008] In this case, "polarity" refers to the voltage's sign. For example, the first polarity can be positive and the second negative, or vice versa.

[0009] Preferably, the transmitting coil generates a magnetic field with a main axis along the transmitting winding axis as a pulse signal.

[0010] Preferably, the receiving coils intersect. This means, in particular, that the first receiving winding axis and the second receiving winding axis intersect each other.

[0011] The pulse signal is conveniently generated periodically. The pulse signal is therefore generated at a frequency, which is also referred to as the pulse frequency. The period thus has a period duration corresponding to the pulse frequency.

[0012] The positioning device preferably generates / determines position information which represents the detected relative position of the transmitting coil to the receiver and thus the detected relative position of the induction charging devices which interact inductively with each other during charging operation.

[0013] The position information is advantageously provided to an assistance device, in particular a driver assistance device, in order to achieve a relative movement of the mobile induction charging device, in particular the mobile application, to the stationary induction charging device, which leads to an optimization of the inductive energy transfer and thus to an optimal positioning of the energy coils relative to one another. This can be done, for example, via a human-machine interface, also known by the English abbreviation "HMI", in order to transmit appropriate recommendations to a user of the mobile application, in particular a vehicle driver. Alternatively or additionally, the assistance device can move the mobile application at least partially autonomously, in particular drive it, taking the position information into account in order to achieve the optimized positioning.

[0014] In advantageous embodiments, the receiving winding axes run transversely to each other.

[0015] In preferred embodiments, it is detected that the transmitting device is spaced apart from the receiving device along the first receiving winding axis when a first voltage is induced but no second voltage is induced. Thus, not only a relative position along the transmitting winding axis but also a spaced arrangement along the first receiving winding axis is detected in a simple and reliable manner.

[0016] In this case, “no voltage” means a voltage of 0 or a negligible voltage.

[0017] It is advantageously recognized that the transmitting device is arranged in front of the receiving device along the first receiving winding axis when the first voltage has a first polarity. It is also advantageously recognized that the transmitting device is arranged behind the receiving device along the first receiving winding axis when the first voltage has a second polarity that is opposite to the first polarity. In this way, the direction of the distance along the first receiving winding axis is also recognized.

[0018] Embodiments are considered advantageous in which it is detected that the transmitting device is spaced apart from the receiving device along the second receiving winding axis when a second voltage, rather than a first voltage, is induced. Thus, not only a relative position along the transmitting winding axis but also a spaced arrangement along the second receiving winding axis is detected in a simple and reliable manner.

[0019] Preferably, it is detected that the transmitting device is arranged in front of the receiving device along the second receiving winding axis if the second voltage has a first polarity. Furthermore, it is detected that the transmitting device is arranged behind the receiving device along the second receiving winding axis if the second voltage has a second polarity that is opposite to the first polarity. Thus, the direction of the distance along the second receiving winding axis is also detected.

[0020] In preferred embodiments, the second direction runs parallel to a direction of travel of the mobile induction charging device, in particular of the associated motor vehicle, when traveling straight ahead to the stationary induction charging device and thus during charging operation. This also means that the transmitting winding axis runs parallel to the direction of travel. Thus, it is recognized that the transmitting device is arranged in front of the receiving device along the direction of travel if the induced voltages both have the first polarity. Furthermore, it is recognized that the transmitting device is arranged behind the receiving device along the direction of travel if the induced voltages have the second polarity. This leads to a particularly simple assignment with regard to the direction of travel and thus to simplified relative positioning of the induction charging devices to one another.

[0021] In advantageous embodiments, the receiving winding axes are inclined to the direction of travel. This means that the receiving coils are wound around receiving winding axes that are inclined to the direction of travel. This results in a clear differentiation in the induced voltages and thus simplified detection of the corresponding relative position.

[0022] The pulse signal can theoretically be generated over the entire period.

[0023] In preferred embodiments, the pulse signal is generated with a duty cycle of at least 50% of the period, for example 70% or 75% of the period. This means that the pulse signal is generated within the respective period over a limited duration, which corresponds to at least 50% of the period, for example 70% of the period or 75% of the period. Advantageously, the respective receiving coil is also sampled to detect the voltage at a sampling rate which corresponds to N times the pulse frequency, so that N voltage values ​​are present per period. In this case, a positive polarity of the induced voltage is detected in the respective receiving coil if the number of voltage values ​​with a high voltage is greater than the number of voltage values ​​with a lower voltage compared to the high voltage.In addition, negative polarity of the induced voltage is detected if the number of voltage values ​​with a low voltage is greater than the number of voltage values ​​with a high voltage compared to the low voltage. This simplifies the implementation of the method while simultaneously reliably and easily detecting the voltage polarity.

[0024] In preferred embodiments, the pulse signal is repeated periodically with a duty cycle of 75% of the period duration. Furthermore, the respective receiving coil is sampled at a sampling rate corresponding to four times the pulse frequency. Thus, four voltage values ​​are available per pulse duration. This reduces the required sampling rates, resulting in a simple and cost-effective implementation of the method while simultaneously increasing reliability.

[0025] It is conceivable to equip the respective stationary induction charging device with such a receiving device, i.e. with such a receiver, and the respective mobile induction charging device with such a transmitting device, i.e. with such a transmitting coil.

[0026] In preferred embodiments, the respective stationary induction charging device is equipped with such a transmitting device, and the respective mobile induction charging device is equipped with such a receiving device. Thus, the relative position is detected in the mobile induction charging device. This leads to reduced latencies in the implementation of the relative positioning, particularly in the generation of the position information. The result is smoother positioning of the induction charging devices relative to one another.

[0027] It is understood that the receiver may have additional receiving coils in addition to the first receiving coil and second receiving coil.

[0028] It is understood that, in addition to the method for operating the system, a system operated in this way also falls within the scope of this invention. For this purpose, the positioning device, in particular, is designed accordingly.

[0029] The method is advantageously implemented by means of a computer program product which contains corresponding instructions.

[0030] The computer program product therefore comprises instructions which, when the computer program product is executed by the system, in particular by the positioning device, cause the system to carry out the method.

[0031] Further important features and advantages of the invention emerge from the subclaims, from the drawings and from the associated description of the figures based on the drawings.

[0032] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0033] 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.

[0034] They show, schematically Fig. 1 a highly simplified, circuit diagram-like representation of a system for inductive energy transfer in a charging operation of two induction charging devices, Fig. 2 a simplified plan view of an induction charging device with a transmitting device of a positioning device of the system, Fig. 3 a plan view of a receiver of a receiving device of the positioning device with receiving coils, Fig. 4 a diagram of a pulse signal of a transmitting coil of the transmitting device, Fig. 5 a simplified plan view of the transmitting coil and the receiver at a first relative position of the transmitting coil and the receiver to each other, Fig. 6 diagrams of voltages induced in the receiving coils by the pulse signal at the relative position of the Fig. 5, Fig. 7 a simplified plan view of the transmitting coil and the receiver in a second relative position of the transmitting coil and the receiver to each other, Fig. 8 diagrams of voltages induced in the receiving coils by the pulse signal at the relative position of the Fig. 7, Fig. 9 a simplified plan view of the transmitting coil and the receiver in a third relative position of the transmitting coil and the receiver to each other, Fig. 10 diagrams of voltages induced in the receiving coils by the pulse signal at the relative position of the Fig. 9, Fig. 11 a simplified plan view of the transmitting coil and the receiver in a fourth relative position of the transmitting coil and the receiver to each other, Fig. 12 diagrams of voltages induced in the receiving coils by the pulse signal at the relative position of the Fig. 11, Fig. 13 a simplified plan view of the transmitting coil and the receiver at a fifth relative position of the transmitting coil and the receiver to each other, Fig. 14 diagrams of voltages induced in the receiving coils by the pulse signal at the relative position of the Fig. 13, Fig. 15 a simplified plan view of the transmitting coil and the receiver in a sixth relative position of the transmitting coil and the receiver to each other, Fig. 16 diagrams of voltages induced in the receiving coils by the pulse signal at the relative position of the Fig. 15, Fig. 17 is a diagram of the pulse signal in another embodiment, Fig. 18 a diagram of a voltage induced in one of the receiving coils by the pulse signal.

[0035] For example, in Fig. System 1 shown as an example is used for inductive energy transfer. Fig. 1, the system 1 comprises for this purpose at least two induction charging devices 2, namely at least one stationary induction charging device 2, 2a and at least one mobile induction charging device 2, 2b. In a Fig. 1, the respective stationary induction charging device 2, 2a can inductively interact with one of the at least one mobile induction charging device 2, 2b for inductive energy transmission. In charging operation, the respective stationary induction charging device 2 can thus be a charging point of the system 1. For inductive energy transmission, the respective induction charging device 2, as shown in particular in Fig. 1, a coil 3, which is also referred to below as energy coil 3. Thus, the respective stationary induction charging device 2, 2a has a stationary energy coil 3, 3a (see also Fig. 2) and the respective mobile induction charging device 2, 2b has a mobile energy coil 3, 3b. One of the energy coils 3 serves as a primary coil during charging, generating an alternating magnetic field that induces a voltage for energy transfer in the other energy coil 3, which serves as a secondary coil. As shown in Fig. 1, during charging operation, the induction charging devices 2, in particular the energy coils 3 of the induction charging devices 2, which cooperate for inductive energy transmission, are spaced apart from one another and arranged opposite one another in a direction R1, which is also referred to below as the first direction R1. This induction charging device 2 and its energy coils 3 are also referred to below as "associated". The respective mobile induction charging device 2, 2b is provided in an associated mobile application 100. In the exemplary embodiments shown, the application 100 is a motor vehicle 101. The first direction R1 runs along, in particular parallel, to the Z direction of the motor vehicle 101. The first direction R1 therefore corresponds in particular to a height direction.In addition, in order to enable charging and achieve high levels of efficiency during charging, the associated energy coils 3 are positioned accordingly relative to one another transversely to the first direction R1, i.e. in a second direction R2 running transversely to the first direction R1 and in a third direction R3 running transversely to the first direction R1 and transversely to the second direction R2. With this positioning, the associated energy coils 3 preferably overlap at least partially in the second direction R2 and in the third direction R3. In the exemplary embodiments shown, the second direction R2 is the direction of travel of the mobile application 100 or of the motor vehicle 101, i.e. the X direction of the motor vehicle 101, during charging. During energy transmission, as shown in . Fig. 1, energy can be transferred, in particular inductively, to the mobile induction charging device 2, 2b in order to charge a battery 102 of the mobile application 100. For this purpose, a rectifier 50 can be provided between the mobile energy coil 3, 3b and the battery 102, which converts the voltage induced in the mobile energy coil 3, 3b into a rectified voltage. In the exemplary embodiment shown, the rectifier 50 is, purely by way of example, a component of the mobile induction charging device 2, 2b. The inductive energy transfer can also take place from the mobile induction charging device 2, 2b to the stationary induction charging device 2, 2a, i.e., in principle, also bidirectionally.

[0036] A positioning device 4 of the system 1 serves to detect the relative position of the associated induction charging devices 2 during charging operation, and thus the associated energy coils 3, to one another. This can be used in the context of driver assistance to position the mobile application 100, in particular the motor vehicle 101, accordingly to the stationary induction charging device 2, 2a. For this purpose, the positioning device 4 has a transmitting device 5 in one of the induction charging devices 2 and a receiving device 6 in the other induction charging device 2. In the exemplary embodiments shown, the transmitting device 5 is a component of the stationary induction charging device 2, 2a, and the receiving device 6 is a component of the mobile induction charging device 2, 2b.The respective stationary induction charging device 2, 2a thus has such a transmitting device 5 and the respective mobile induction charging device 2, 2b has such a receiving device 6.

[0037] The transmitting device 5 has a particularly Fig. 2. The transmitting coil 7 is wound around a predetermined winding axis A1, which is also referred to below as the transmitting winding axis A1. The transmitting winding axis A1 runs parallel to the second direction R2. Thus, in the exemplary embodiments shown, the transmitting winding axis A1 runs parallel to the X direction of the motor vehicle 101 during charging operation and consequently to the direction of travel.

[0038] The receiving device 6 has a particularly in Fig. 3. The receiver 8 has two receiving coils 9, 10, namely a first receiving coil 9 and a second receiving coil 10. The respective receiving coil 10 is wound around a predetermined and associated winding axis A2, A3, wherein the winding axes A2, A3 run transversely to the first direction R1 and inclined or transversely to one another. The first receiving coil 9 is therefore wound around a predetermined first receiving winding axis A2, which runs transversely to the first direction R1. The second receiving coil 10 is wound around a predetermined second receiving winding axis A2, which runs transversely to the first direction R1 and inclined or transversely to the first receiving winding axis A2. In the exemplary embodiments shown, the receiving winding axes A2, A3 run transversely to one another. Furthermore, in the exemplary embodiments shown, the receiving coils 9, 10 cross one another.

[0039] To detect the relative position of the receiver 8 to the transmitting coil 7 and thus of the mobile induction charging device 2, 2b to the stationary induction charging device 2, 2a, a predetermined pulse signal P is generated with the transmitting coil 7, which Fig. 4 is indicated by a diagram. The pulse signal P is conveniently generated periodically. The pulse signal is therefore repeated at a frequency, which is also referred to as pulse frequency, to which a period duration D is associated (see Fig. 4). In Fig. 4 shows only one such pulse signal P. In the illustrated embodiments, the pulse signal P is a magnetic field.

[0040] As shown below using the Fig. As explained in Figures 5 to 18, a voltage U induced by the pulse signal P is determined in the respective receiving coil 9, 10, and the polarity of the induced voltages U is used to detect relative offsets of the induction charging devices 2 to one another, including the direction of the offset. This means that a first voltage U1 induced in the first receiving coil 9 by the pulse signal P and a second voltage U2 induced in the second receiving coil 10 by the pulse signal P are determined, and the relative offset of the receiver 8 to the transmitting coil 7 is detected based on the polarity of the voltages U thus determined.

[0041] This shows Fig. 5 shows a relative position of the receiver 8 to the transmitting coil 7, in which the transmitting coil 7 and thus the transmitting device 5 is arranged along the transmitting winding axis A1 in front of the receiver 8 and thus in front of the receiving device 6. In the embodiments shown, the representation of the Fig. 5 the stationary induction charging device 2, 2a is arranged along the direction of travel in front of the mobile induction charging device 2, 2b. Fig. 6 shows diagrams of the corresponding voltages U, which are in the position of the Fig. 5 are induced in the receiving coils 9, 10. The left diagram shows the first voltage U1 induced in the first receiving coil 9 for a pulse signal P, and the right diagram shows the second voltage U2 induced in the second receiving coil 10. As Fig. 6, both have the same Fig. In the position shown in Figure 5, the induced voltages U have the same polarity, hereinafter also referred to as the first polarity. In the illustrated embodiment, both induced voltages U have a positive polarity. Therefore, it is recognized that the transmitting device 5 is arranged in front of the receiving device 6 along the transmitting winding axis A1 if the induced voltages U both have the first polarity.

[0042] Fig. 7 shows a relative position of the receiver 8 to the transmitting coil 7, in which the transmitting coil 7 and thus the transmitting device 5 is arranged along the transmitting winding axis A1 behind the receiver 8 and thus behind the receiving device 6. Fig. 8 shows, in an analogous manner to Fig. 6, two diagrams of the positions of the Fig. 7 induced voltages U. How Fig. 8, both of the Fig. In the position shown in Figure 5, the induced voltages U have the same polarity, which, however, is opposite to the first polarity and is also referred to below as the second polarity. In the exemplary embodiments shown, the second polarity is negative. Therefore, it can be seen that the transmitting device 5 is arranged behind the receiving device 6 along the transmitting winding axis A1 when the induced voltages U both have the second polarity, which is opposite to the first polarity.

[0043] The Fig. 9 and Fig. 11 each show a position in which the transmitting device 5 is spaced apart from the receiving device 6 along the first receiving winding axis A2, and in which the first receiving winding axis A2 and the transmitting winding axis A1 run parallel to one another, coaxially in the embodiment shown. Fig. 9 shows a position in which the first receiving winding axis A2 runs parallel to the direction of travel. In a similar manner to the Fig. 6 and Fig. 8 show the Fig. 10 and Fig. 12 the corresponding induced voltages U, that is, in the left diagram the first voltage U1 induced in the first receiving coil 9 and in the right diagram the second voltage U2 induced in the second receiving coil 10. As the Fig. 10 and Fig. 12 can be seen, is used in the Fig. 9 and Fig. 11, a voltage is induced in the first receiving coil 9 and no voltage is induced in the second receiving coil 10. It is therefore recognized that the transmitting device 5 is spaced apart from the receiving device 6 along the first receiving winding axis A2 and parallel to the transmitting winding axis A1 when a first voltage U1 and no second voltage U2 is determined. As a comparison of the Fig. 9 to 12, the first voltage U1 has a different polarity depending on whether the transmitting device 5 is arranged in front of or behind the receiving device 6 along the first receiving winding axis A2. It is therefore recognized that the transmitting device 5 is arranged in front of the receiving device 6 along the first receiving winding axis A2 if the first voltage U1 has a first polarity, which is positive in the exemplary embodiments shown. It is also recognized that the transmitting device 5 is arranged behind the receiving device 6 along the first receiving winding axis A2 if the first voltage U1 has a second polarity which is opposite to the first polarity. In the exemplary embodiments shown, the second polarity is negative.

[0044] In the Fig. 13 and Fig. 15 shows positions in which the transmitting device 5 is spaced apart from the receiving device 6 along the second receiving winding axis A3, wherein the second receiving winding axis A3 and the transmitting winding axis A1 run parallel, coaxially in the embodiment shown. Fig. 14 shows in an analogous manner to Fig. 12 which in the position of the Fig. 13 induced voltages U and Fig. 16 in an analogous manner to Fig. 12 which in the position of the Fig. 15 induced voltages U, i.e. in the left diagram the first induced voltage U1 and in the right diagram the second induced voltage U2. In an analogous manner to the explanation of the Fig. 9 to 12 is used in the Fig. 13 and Fig. 15, a voltage U1 is induced in the second receiving coil 10 and no voltage U2 is induced in the first receiving coil 9. It is recognized that the transmitting device 5 is spaced apart from the receiving device 6 along the second receiving winding axis A3 and parallel to the transmitting winding axis A1 when a second voltage U2 and no first voltage U1 is determined. As a comparison of the Fig. 13 to 16, the second voltage U1 has a different polarity depending on whether the transmitting device 5 is arranged in front of or behind the receiving device 6 along the second receiving winding axis A3. It is therefore recognized that the transmitting device 5 is arranged in front of the receiving device 6 along the second receiving winding axis A3 if the second voltage U2 has a first polarity, which is positive in the exemplary embodiments shown. It is also recognized that the transmitting device 5 is arranged behind the receiving device 6 along the second receiving winding axis A3 if the second voltage U2 has a second polarity which is opposite to the first polarity. In the exemplary embodiments shown, the second polarity is negative.

[0045] As in Fig. As shown in Figure 17, the pulse signal P can alternatively be generated with a duty cycle of at least 50% of the period D. In the illustrated embodiment, the pulse signal P is generated with a duty cycle of 75% of the period D. Fig. 18 shows a signal in one of the receiving coils 9, 10 due to one of the Fig. 17 shown pulse signal P induced voltage U. Arrows indicate Fig. 18 indicates a sampling rate with which the induced voltage U is sampled. Accordingly, the respective receiving coil 9, 10 is sampled to detect the induced voltage U at a sampling rate that corresponds to N times the pulse frequency. In the exemplary embodiment shown, the sampling rate corresponds to four times the pulse frequency. Thus, voltage values ​​are present per period DN. In the exemplary embodiment shown, four voltage values ​​are present per period D. A positive polarity of the induced voltage U is detected if the number of voltage values ​​with a high voltage is greater than the number of voltage values ​​with a lower voltage compared to the high voltage, as in Fig. 18. In contrast, a negative polarity of the induced voltage U is detected when the number of voltage values ​​with a low voltage is greater than the number of voltage values ​​with a high voltage compared to the low voltage (not shown).

[0046] The positioning device 4 generates position information dependent on the thus detected relative position. The position information thus represents the relative position of the induction charging devices 2 to one another. The position information can be provided to an assistance device 103 of the mobile application 100, in particular of the motor vehicle 101, as shown in Fig. 1. The assistance device 103 advantageously generates based on the received position information, as shown in Fig.1, indicated by arrows, are navigation instructions for the mobile application 100. The navigation instructions can be provided to a user of the mobile application 100 for guiding the mobile application 100, for example, via a human-machine interface (not shown). Likewise, the navigation instructions can be used for at least partially autonomous guidance of the mobile application 100, in particular for at least partially autonomous driving of the motor vehicle 101. The navigation instructions serve the purpose of achieving improved positioning of the associated energy coils 3 to optimize energy transfer.

[0047] The method is preferably implemented using a computer program product. The computer program product is preferably stored at least partially in the positioning device 4 on a non-volatile memory (not shown). The computer program product comprises instructions that, when the computer program product is executed by the positioning device 4, cause the positioning device 4 to operate the system 1 as described.

Claims

[1] Method for operating a system (1) for inductive energy transmission, - wherein the system (1) comprises at least one stationary induction charging device (2, 2a) and at least one mobile induction charging device (2, 2b), in particular of at least one motor vehicle (101), and wherein: • the respective stationary induction charging device (2, 2a) has a stationary energy coil (3, 3a) and the respective mobile induction charging device (2, 2b) has a mobile energy coil (3, 3b), • the respective stationary induction charging device (2, 2a) interacts with one of the at least one mobile induction charging device (2, 2b) in a charging operation in order to inductively transmit energy by means of the energy coils (3), • the inductive charging devices (2) which interact inductively during charging operation are arranged opposite one another and spaced apart from one another in a first direction (R1), • the system (1) has a positioning device (4) for detecting the relative position of the induction charging devices (2) associated with each other during charging operation, • the positioning device (4) has a transmitting device (5) in one of the induction charging devices (2) associated in the charging mode and a receiving device (6) in the other induction charging device (2), • the transmitting device (5) has a transmitting coil (7) which is wound around a predetermined transmitting winding axis (A1) which runs parallel to a second direction (R2) running transversely to the first direction (R1), • the receiving device (10) comprises a receiver (8) with a first receiving coil (9) and a second receiving coil (10), • the first receiving coil (9) is wound around a predetermined first receiving winding axis (A2) which runs transversely to the first direction (R1), • the second receiving coil (10) is wound around a predetermined second receiving winding axis (A3) which runs transversely to the first direction (R2) and inclined or transversely to the first receiving winding axis (A2), - wherein a predetermined pulse signal (P) is generated by the transmitting coil (7), - wherein a first voltage (U, U1) induced in the first receiving coil (9) by means of the pulse signal (P) and a second voltage (U, U2) induced in the second receiving coil (10) by means of the pulse signal (P) are determined, • wherein it is recognized that the transmitting device (5) is arranged along the transmitting winding axis (A1) in front of the receiving device (6) when the induced voltages (U) both have a first polarity, • wherein it is recognized that the transmitting device (5) is arranged behind the receiving device (6) along the transmitting winding axis (A1) when the induced voltages (U) both have a second polarity which is opposite to the first polarity. [2] Method according to claim 1, characterized by that the receiving winding axes (A2, A3) run transversely to one another, wherein it is recognized that the transmitting device (5) is spaced apart from the receiving device (6) along the first receiving winding axis (A2) and parallel to the transmitting winding axis (A1) when a first voltage (U, U1) and no second voltage (U, U2) is determined. [3] Method according to claim 2, characterized by , - that it is detected that the transmitting device (5) is arranged along the first receiving winding axis (A2) in front of the receiving device (6) when the first voltage (U, U1) has a first polarity, - that it is recognized that the transmitting device (5) is arranged behind the receiving device (6) along the first receiving winding axis (A2) when the first voltage (U, U1) has a second polarity which is opposite to the first polarity. [4] Method according to one of claims 1 to 3, characterized by that it is recognized that the transmitting device (5) is spaced apart from the receiving device (6) along the second receiving winding axis (A3) and parallel to the transmitting winding axis (A1) when a second voltage (U, U2) and no first voltage is determined. [5] Method according to claim 4, characterized by , - that it is recognized that the transmitting device (5) is arranged along the second receiving winding axis (A3) in front of the receiving device (6) when the second voltage (U, U2) has a first polarity, - that it is recognized that the transmitting device (5) is arranged behind the receiving device (6) along the second receiving winding axis (A3) when the second voltage (U, U2) has a second polarity which is opposite to the first polarity. [6] Method according to one of claims 1 to 5, characterized by that the second direction (R2) runs parallel to a direction of travel of the mobile induction charging device (2, 2a) during charging operation, so that - it is detected that the transmitting device (5) is arranged in front of the receiving device (6) along the direction of travel if the induced voltages (U) both have the first polarity, - it is detected that the transmitting device (5) is arranged behind the receiving device (6) along the direction of travel when the induced voltages (U) have the second polarity. [7] Method according to claim 6, characterized bythat the receiving winding axes (A, A2) are inclined to the direction of travel. [8] Method according to one of claims 1 to 7, characterized by , - that the pulse signal (P) is repeated periodically at a pulse frequency, - that the pulse signal (P) is generated with a duty cycle of at least 50% of a period duration (D) associated with the period frequency, for example 70% or 75% of the period duration (D), - that the respective receiving coil (9, 10) is sampled for detecting the induced voltage (U) at a sampling rate which corresponds to N times the pulse frequency, so that N voltage values ​​are present per period (D), - that in the respective receiving coil (9, 10) • a positive polarity of the induced voltage (U) is detected if the number of voltage values ​​with a high voltage is greater than the number of voltage values ​​with a lower voltage compared to the high voltage, • a negative polarity of the induced voltage (U) is detected if the number of voltage values ​​with a low voltage is greater than the number of voltage values ​​with a high voltage compared to the low voltage. [9] Method according to claim 8, characterized by , - that the pulse signal (P) is repeated periodically with a duty cycle of 75% of the period duration (D), - that the respective receiving coil (9, 10) is sampled at a sampling rate which corresponds to four times the period duration (D). [10] Method according to one of claims 1 to 9, characterized by that the respective stationary induction charging device (2, 2a) is equipped with such a transmitting device (5) and the respective mobile induction charging device (2, 2b) is equipped with such a receiving device (6). [11] System (1) for inductive energy transmission, which has at least one stationary induction charging device (2, 2a) and at least one mobile induction charging device (2, 2b), in particular of at least one motor vehicle (101), - wherein the respective stationary induction charging device (2, 2a) has a stationary energy coil (3, 3a) and the respective mobile induction charging device (2, 2b) has a mobile energy coil (3, 3b), - wherein the respective stationary induction charging device (2, 2a) cooperates with one of the at least one mobile induction charging device (2, 2b) in a charging operation in order to inductively transmit energy by means of the energy coils (3), - wherein the inductive charging devices (2) which interact inductively during charging operation are arranged opposite one another and spaced apart from one another in a first direction (R1), - wherein the system (1) comprises a positioning device (4) for detecting the relative position of the induction charging devices (2) associated with each other during charging operation, - wherein the positioning device (4) has a transmitting device (5) in one of the induction charging devices (2) associated in the charging operation and a receiving device (6) in the other induction charging device (2), - wherein the transmitting device (5) has a transmitting coil (7) which is wound around a predetermined transmitting winding axis (A1) which runs parallel to a second direction (R2) extending transversely to the first direction (R1), - wherein the receiving device (6) comprises a receiver (8) with a first receiving coil (9) and a second receiving coil (10), - wherein the first receiving coil (9) is wound around a predetermined first receiving winding axis (A2) which runs transversely to the first direction (R1), - wherein the second receiving coil (10) is wound around a predetermined second receiving winding axis (A3) which runs transversely to the first direction (R1) and inclined or transversely to the first receiving winding axis (A2), - wherein the positioning device (4) is designed such that it operates the system (1) according to the method according to one of the preceding claims.

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