VEHICLE CHARGING SYSTEM FOR CHARGING AN ENERGY STORE ARRANGED IN A VEHICLE

Abstract

A system for charging an energy store in a vehicle and a method for operating the system, wherein the system includes a first transmission unit having a primary coil, arranged outside the vehicle in a stationary manner, and a second transmission unit having a secondary coil, arranged in the vehicle, wherein energy is transmitted via inductive energy transmission from the primary coil to the secondary coil to charge the energy store. The second transmission unit has a signal generator for generating and coupling signals into the secondary coil for transmission via the secondary coil, and the first transmission unit has an evaluation unit, a first auxiliary coil, and a second auxiliary coil, wherein the evaluation unit is designed to ascertain a magnetic coupling and/or a relative position between the first transmission unit and the second transmission unit based on the signals received by the primary coil and the auxiliary coils.

Claims

1. A vehicle charging system for charging an energy store arranged in a vehicle F, the system comprising a first transmission unit GPM, which has a primary coil with a coil axis SPA.sub.P and is arranged outside of the vehicle F in a stationary manner, and a second transmission unit CPM, which has a secondary coil with a coil axis SPA.sub.S and is arranged in the vehicle F, wherein energy is transmitted via an inductive energy transmission from the primary coil to the secondary coil in order to charge the energy store, wherein: the second transmission unit CPM has a signal generator SG for generating signals SIG.sub.SG, the signal generator coupling the signals SIG.sub.SG into the secondary coil in order to transmit the signals via the secondary coil; and the first transmission unit GPM has an evaluation unit and at least one first auxiliary coil with a coil axis SPA.sub.H1 and one second auxiliary coil with a coil axis SPA.sub.H2, the evaluation unit being designed to ascertain a magnetic coupling k.sub.mag and/or the relative position ΔPOS between the first transmission unit GPM and the second transmission unit CPM based on the signals SIG.sub.SG received by the primary coil, the first auxiliary coil, and the secondary auxiliary coil.

2. The vehicle charging system according to claim 1, wherein the first auxiliary coil and the second auxiliary coil are arranged and oriented relative to the primary coil and relative to one another.

3. The vehicle charging system according to claim 1, wherein the coil axis SPA.sub.H1 and the coil axis SPA.sub.H2 are each aligned substantially orthogonally with respect to the coil axis SPA.sub.P of the primary coil and substantially orthogonally with respect to one another.

4. The vehicle charging system according to claim 1, wherein the evaluation unit ascertains the relative position ΔPOS based on respective amplitudes and/or phase positions of the signals SIG.sub.SG received by the primary coil, the first auxiliary coil, and the second auxiliary coil.

5. The vehicle charging system according to claim 1, wherein the evaluation unit ascertains the magnetic coupling k.sub.mag based on a voltage U.sub.2 generated in the secondary coil for transmission of the signal SIG.sub.SG or based on a current I.sub.2 generated in the secondary coil, a voltage U.sub.1 or a current I.sub.1 induced in the primary coil on receipt of the signal SIG.sub.SG, and predefined self-inductances L1 and L2 of the primary coil and the secondary coil.

6. The vehicle charging system according to claim 1, wherein the second transmission unit CPM is designed and configured to end transmission of signals SIG.sub.SG when the magnetic coupling k.sub.mag is greater than a predefined limit value G1 and/or when a distance D.sub.GPM-CPM ascertained from the relative position ΔPOS between the first transmission unit GPM and the second transmission unit CPM is less than a predefined limit value G2.

7. The vehicle charging system according to claim 1, wherein the inductive energy transmission from the primary coil to the secondary coil in order to charge the energy store is only initialized when the ascertained magnetic coupling k.sub.mag is greater than a predefined limit value G3 and/or when a distance D.sub.GPM-CPM ascertained from the relative position ΔPOS between the first transmission unit GPM and the second transmission unit CPM is smaller than a predefined limit value G4.

8. A method of operating a vehicle charging system according to claim 1, the method comprising: generating and coupling signals SIG.sub.SG by the signal generator SG in order to transmit the signals into the secondary coil; and ascertaining the magnetic coupling k.sub.mag and/or the relative position ΔPOS between the first transmission unit GPM and the second transmission unit CPM based on the signals SIG.sub.SG received by the primary coil, the first auxiliary coil, and the second auxiliary coil.

9. A vehicle charging system for charging an energy store arranged in a vehicle F, the system comprising a first transmission unit GPM, which has a primary coil with a coil axis SPA.sub.P and is arranged outside of the vehicle F in a stationary manner, and a second transmission unit CPM, which has a secondary coil with a coil axis SPA.sub.S and is arranged in the vehicle F, wherein energy is transmitted via an inductive energy transmission from the primary coil to the secondary coil, wherein: the first transmission unit GPM has a signal generator SG for generating signals SIG.sub.SG, the signal generator coupling the signals SIG.sub.SG into the primary coil in order to transmit the signals; and the second transmission unit CPM has an evaluation unit and at least one first auxiliary coil with a coil axis SPA.sub.H1 and one second auxiliary coil with a coil axis SPA.sub.H2, the evaluation unit being designed to ascertain and provide at an interface for further use a magnetic coupling k.sub.mag and/or the relative position ΔPOS between the first transmission unit GPM and the second transmission unit CPM based on the signals SIG.sub.SG received by the secondary coil, the first auxiliary coil, and the second auxiliary coil.

10. A method of operating a vehicle charging system according to claim 9, the method comprising: generating and coupling signals SIG.sub.SG by the signal generator SG in order to transmit the signals into the primary coil; and ascertaining the magnetic coupling k.sub.mag and/or the relative position ΔPOS between the first transmission unit GPM and the second transmission unit CPM based on the signals SIG.sub.SG received by the secondary coil, the first auxiliary coil, and the second auxiliary coil.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In the drawings:

[0052] FIG. 1 is a highly schematic structure of a vehicle charging system according to the invention; and

[0053] FIG. 2 is a highly schematic flowchart of a method according to the invention for operating a vehicle charging system.

DETAILED DESCRIPTION

[0054] FIG. 1 is a highly schematic structure of a vehicle charging system according to the invention for charging an energy store arranged in a vehicle F. The vehicle charging system shown in FIG. 1 includes a first transmission unit GPM 101, which has a primary coil 103 with a coil axis SPA.sub.P (not shown) and is arranged on the ground outside of the vehicle in a stationary manner. The vehicle charging system further includes a second transmission unit CPM 102, which has a secondary coil 104 with a coil axis SPA.sub.S (not shown) and is arranged in the vehicle F. The energy transmission in order to charge the energy store via an inductive energy transmission takes place from the primary coil 103 to the secondary coil 104.

[0055] All components relating to the transmitting and receiving of the inductive charging energy for the energy store in the second transmission unit CPM 102 have been omitted in FIG. 1 for the sake of clarity.

[0056] Before the inductive energy transmission can be initiated/activated in the first transmission unit GPM, the presence of a second transmission unit CPM in a vehicle F, the relative position thereof and the current magnetic coupling between the first transmission unit GPM and the second transmission unit CPM must first be ascertained, wherein the inductive transmission transfer is only initiated when the ascertained relative position ΔPOS and the ascertained magnetic coupling k.sub.mag satisfy the specified conditions.

[0057] The second transmission unit CPM 102 arranged in the vehicle F has a signal generator SG 105 for generating signals SIG.sub.SG, the signal generator coupling the signals SIG.sub.SG into the secondary coil 104 in order to transmit the signals via the secondary coil. In the present case, the signal generator SG 105 is also connected to a transmitting/receiving unit 109 that, among other things, transmits the following information via a WLAN signal: identifier of the second transmission unit CPM 102, electrical status of the transmission unit CPM 102, the voltage U.sub.2 or current I.sub.2 generated in the secondary coil 104 for the transmission of the signals SIG.sub.SG and the inductance L.sub.2 of the secondary coil 104. The dashed arrows emanating from the secondary coil 104 represent the transmitted signals SIG.sub.SG.

[0058] The transmitting/receiving unit 109 of the second transmission unit CPM 102 is also connected to a vehicle-mounted control unit 110 that controls in particular an autonomous longitudinal and/or lateral control of the vehicle F and/or controls the output/display of information in the vehicle F for optimum relative positioning of the first transmission unit GPM 101 with respect to the second transmission unit CPM 102.

[0059] The first transmission unit GPM 101 has an evaluation unit 106 and at least one first auxiliary coil 107a with a coil axis SPA.sub.H1 (not shown) and one second auxiliary coil 107b with a coil axis SPA.sub.H2 (not shown). The coil axes SPA.sub.H1 and SPA.sub.H2 are each aligned substantially orthogonally with respect to the coil axis SPA.sub.P of the primary coil and substantially orthogonally with respect to one another.

[0060] The evaluation unit 106 is configured to ascertain a current magnetic coupling k.sub.mag and the current relative position ΔPOS between the first transmission unit GPM 101 and the second transmission unit CPM 102 on the basis of the signals SIG.sub.SG received by the primary coil 103 and the auxiliary coils 107a,b. The evaluation unit 106 is connected to a transmitting/receiving unit 108 such that the ascertained values for the magnetic coupling k.sub.mag and for the relative position POS as well as a distance D.sub.GPM-CPM ascertained therefrom between the first and the second transmission unit are transmitted to the second transmission unit CPM 102, specifically via the data connection between the transmitting/receiving units 108 and 109. The data on the current relative position ΔPOS and on the magnetic coupling k.sub.mag are transmitted from the transmitting/receiving unit 109 to the vehicle-mounted control unit 110 and used by the latter for the autonomous longitudinal and lateral control of the vehicle F such that the vehicle F autonomously optimally positions the second transmission unit CPM 102 relative to the first transmission unit GPM 101.

[0061] If such optimal positioning has taken place, which can be seen on the basis of predefined limit values, in particular for the magnetic coupling k.sub.mag, and if the vehicle F has been placed in a parked state such that no further movement of the vehicle F is to be expected, the inductive energy transmission in order to charge the vehicle-mounted energy store is initiated.

[0062] FIG. 2 is a highly schematic flowchart of a method according to the invention for operating a vehicle charging system as described above in FIG. 1. The method includes the following steps.

[0063] In a first step 201, the signal generator SG 105 generates and couples signals SIG.sub.SG in order to transmit the signals into the secondary coil 104.

[0064] In a further step 202, a magnetic coupling k.sub.mag and the relative position POS between the first transmission unit GPM 101 and the second transmission unit CPM 102 are ascertained on the basis of the signals SIG.sub.SG received by the primary coil 103 and the auxiliary coils 107a,b.

[0065] In a further step 203, the ascertained magnetic coupling k.sub.mag and the relative position ΔPOS as well as a distance D.sub.GPM-CPM derived therefrom between the first and the second transmission unit are transmitted to the second transmission unit CPM 102. This data is transmitted between the transmitting unit 108 and the receiving unit 109. The data is transferred using a WLAN protocol. The transmitted data are used, in particular, for forwarding to the vehicle control-mounted unit 110 for autonomous lateral and/or longitudinal control of the vehicle F or for outputting/displaying this information in the vehicle.

[0066] In a further step 204, a check is carried out as to whether the magnetic coupling k.sub.mag and the relative position ΔPOS and the distance D.sub.GPM-CPM satisfy the correspondingly specified conditions. This check can take place in the first transmission unit GPM 101 or in the second transmission unit CPM 102. The inductive energy transmission from the primary coil to the secondary coil is only initiated when the specified conditions are met.

[0067] In the present embodiment, the transmission of the signals SIG.sub.SG, the reception thereof and the evaluation thereof are continued during an inductive energy transmission in order to charge the energy store. If there are changes in the magnetic coupling k.sub.mag, the relative position ΔPOS or the distance D.sub.GPM-CPM that do not meet the specified conditions, the inductive energy transmission in order to charge the energy store is stopped instantaneously.

[0068] Although the invention has been illustrated and explained in greater detail by preferred example embodiments, the invention is not limited by the disclosed examples and other variations may be derived therefrom by a person skilled in the art without departing from the scope of protection of the invention. It is therefore clear that there is a plurality of possible variations. It is also clear that embodiments cited by way of example actually only constitute examples that are not to be interpreted in any way as a limitation of the scope, of the potential applications, or of the configuration of the invention. Instead, the preceding description and the description of the figures enable the person skilled in the art to specifically implement the example embodiments, wherein the person skilled in the art has knowledge of the disclosed inventive concept and is able to make numerous changes, for example, with respect to the function or the arrangement of individual elements cited in an exemplary embodiment, without departing from the scope of protection, which is defined by the claims and their legal equivalents, such as a further explanation in the description.

LIST OF REFERENCE SIGNS

[0069] 101 first transmission unit GPM [0070] 102 second transmission unit CPM [0071] 103 primary coil [0072] 104 secondary coil [0073] 105 signal generator SG [0074] 106 evaluation unit [0075] 107a first auxiliary coil [0076] 107b second auxiliary coil [0077] 108,109 transmitting/receiving unit for data communication [0078] 110 vehicle-mounted control unit [0079] 201-204 method steps