Method and Base Unit for Inductively Charging Electric and Hybrid Vehicles

Abstract

A base unit is provided for a charging station for inductively charging an electrical store of a vehicle. The base unit has a primary coil, which is designed, if there is electromagnetic coupling to a secondary coil of the vehicle, to transmit electrical energy to the secondary coil. The base unit also has an image sensor, which is designed to capture image data of at least a part of the vehicle. In addition, the base unit has a control unit, which is designed to provide or use the image data for positioning the secondary coil in relation to the primary coil.

Claims

1. A base unit for a charging station for inductively charging an energy store of a vehicle, the base unit comprising: a primary coil, which is designed to transfer electrical energy to a secondary coil of the vehicle when there is an electromagnetic coupling with the secondary coil; a sensor, which is designed to sense sensor data from at least a part of the vehicle; and a control unit, which is designed to provide or use the sensor data for a positioning of the secondary coil in relation to the primary coil.

2. The base unit as claimed in claim 1, wherein the sensor is designed for sensing a machine-readable code.

3. The base unit as claimed in claim 2, wherein the machine-readable code comprises one or more of the following data: one or more optimized charging curves, one or more items of frequency information relating to the charging operation, an item of information that represents the position of the secondary coil within the vehicle underfloor, and/or one or more geometrical parameters that represent the arrangement of the secondary coil within the vehicle.

4. The base unit as claimed in claim 1, wherein the sensor is designed to sense image data with respect to an underfloor of the vehicle.

5. The base unit as claimed in claim 1, wherein the sensor is connected to the primary coil; and/or the sensor is moved in a way dependent on the movement of the primary coil.

6. The base unit as claimed in claim 1, wherein the base unit is designed to evaluate image data of an image series or an image sequence, in order to determine a position of the primary coil in relation to the secondary coil via image processing or object recognition.

7. The base unit as claimed in claim 1, wherein the sensor is designed for detecting a predetermined part of the vehicle.

8. The base unit as claimed in claim 1, wherein the sensor is designed for detecting at least two or more parts of the vehicle and for determining the position and/or the angle in relation to at least two or more of the detected parts.

9. The base unit as claimed in claim 1, wherein the base unit is designed to determine on the basis of image data information with respect to a technical parameter of the vehicle.

10. The base unit as claimed in claim 1, further comprising: movement devices which are designed to move the primary coil in order to bring about an electromagnetic coupling between the primary coil and the secondary coil.

11. The base unit as claimed in claim 10, wherein the base unit comprises a frame; the movement devices comprise one or more rails, which are connected to the frame; and the movement devices further comprise actuators, which are designed to move the primary coil along the one or more rails.

12. The base unit as claimed in claim 11, wherein the movement devices further comprise rotation devices, which are designed to rotate the primary coil about a vertical axis of the primary coil.

13. The base unit as claimed in claim 10, wherein the movement devices comprise one or more wheels and/or rollers, which are designed to move the primary coil.

14. The base unit as claimed in claim 4, wherein the base unit comprises lighting, which is designed to generate a light pattern and/or one or more light pulses; and the sensor is designed to sense a reflection of the light pattern and/or of the one or more light pulses on the underfloor of the vehicle.

15. The base unit as claimed in claim 7, wherein the predetermined part of the vehicle is one of the secondary coil, part of vehicle tires, or part of vehicle axles.

16. The base unit according to claim 9, wherein the technical parameter of the vehicle is with respect to the secondary coil or the energy store of the vehicle.

17. A method for positioning a primary coil of a base unit under a secondary coil of a vehicle, the method comprising the acts of: determining sensor data by a sensor of the base unit, wherein the sensor data comprise items of information relating to the position of at least a part of the vehicle; and changing the position of the primary coil and/or of the secondary coil in dependence on the sensor data.

18. A method for positioning a secondary coil of a vehicle in relation to a primary coil of a base unit, wherein the position of the secondary coil of the vehicle is changeable by an activation of an actuator of the vehicle, the method comprising the acts of: determining positioning signals from sensor data of a sensor that is connected to the base unit; transmitting the positioning signals to the vehicle; and activating the actuator of the vehicle in dependence on the transmitted positioning signals in order to bring about an electromagnetic coupling between the primary coil and the secondary coil for inductively charging an energy store of the vehicle.

19. A computer program product, comprising a non-transitory computer readbale medium having stored thereon program code that, when executed by a processor, carries out the method of claim 17.

20. A computer program product, comprising a non-transitory computer readbale medium having stored thereon program code that, when executed by a processor, carries out the method of claim 18.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] FIG. 1 is a schematic diagram of exemplary components of an inductive charging system.

[0055] FIGS. 2A and 2B show the structure of WPT base units given by way of example.

[0056] FIG. 3 shows an exemplary electronic device for controlling the positioning of the WPT base unit and/or the vehicle.

[0057] FIG. 4 shows an exemplary system for positioning the coils for an inductive charging operation.

DETAILED DESCRIPTION OF THE DRAWINGS

[0058] As explained at the beginning, the present document is concerned with methods and devices for positioning the primary coil of a WPT base unit 111 in relation to the secondary coil of a WPT vehicle unit 102 in order to achieve a relatively great magnetic coupling between the primary coil and the secondary coil that is optimized in accordance with the boundary conditions (possibly the maximum possible coupling), and thus achieve a high efficiency of an inductive charging operation.

[0059] The aim here is to make it possible for the driver of a vehicle 100 to park his/her vehicle 100 in the vicinity of an inductive charging station 110, 111 (i.e. in particular in the vicinity of a WPT base unit 111) (for example in a garage or within a public charging location). The occupants of the vehicle 100 can then immediately get out and leave the vehicle 100. An exact positioning of the vehicle 100 in relation to the WPT base unit 111 by the driver is not required. In particular, the driver of the vehicle 100 does not have to wait in the vehicle 100 until the vehicle 100 has automatically maneuvered itself over the charging unit (i.e. over the WPT base unit 111).

[0060] On the other hand, the charging station 110, 111 is designed to adapt itself automatically to the position of the secondary coil. It is not required here that the driver of the vehicle 100 waits for the end of the positioning operation. After automatic positioning of the WPT base unit 111 under the WPT vehicle unit 102 (which can take about 10-30 seconds), the charging operation can be started automatically.

[0061] Also provided may be a device by which a remote-controlled positioning between the vehicle 100 and the base unit 111 can take place. In particular, a manual, remote-controlled positioning can take place by way of a software application on a personal electronic device (for example on a smartphone) of the driver of the vehicle 100. For example, if positioning difficulties occur (for example if the vehicle is positioned at a slant with respect to the base unit 111), the driver can obtain a corresponding message (for example SMS, MMS, email, etc.) by way of a wireless network (for example GMS, UMTS, LTE, WLAN). The driver can in this way be notified that manual positioning is required. The driver can then carry out remote-controlled positioning between the vehicle 100 and the base unit 111 by way of the device described in this document.

[0062] The positioning between the vehicle 100 and the base unit 111 by movement of the base unit 111 and/or by use of a remote control may take place as an alternative or in addition to an automatic positioning of the vehicle 100 over the inductive charging coil (i.e. over the primary coil of the base unit 111).

[0063] FIG. 2A shows the structure of a base unit 111 given by way of example. The base unit 111 includes a primary coil 211, which is arranged movably within a frame of the base unit 111. In particular, the primary coil 211 may be moved in up to two directions (x direction and y direction) in the horizontal plane. Furthermore, a rotating movement of the primary coil 211 may be provided. In the example shown, the base unit 111 includes two running rails 203, which make possible a movement of the primary coil 211 in a first direction (for example the y direction). Furthermore, the base unit 111 includes a transverse rail 201, by which a movement of the primary coil 211 in a second direction (for example the x direction) is made possible. The transverse rail 201 may be moved by way of wheels 202 (for example by way of gear wheels 202) on the running rails 203. The primary coil 211 may furthermore be arranged rotatably within the base unit 111 by way of a rotary joint 204.

[0064] The base unit 111 may include a control unit 205, which is designed to control the movement of the primary coil 211. In particular, suitable motors may be activated in order to move the primary coil 211 along the second direction on the transverse rail 201 and/or in order to move the primary coil 211 along the first direction on the running rails 203 and/or in order to rotate the primary coil 211 by way of the rotary joint 204.

[0065] The control unit 205 may be designed to determine one or more positioning signals, the one or more positioning signals providing items of information concerning how the primary coil 211 is positioned in relation to the secondary coil of the vehicle 100. For example, the one or more positioning signals may comprise:

[0066] (1) The signal strength of an electromagnetic field between the primary coil 211 and the secondary coil. For example, the secondary coil may generate an electromagnetic test field during the positioning operation. The primary coil 211 may receive this test field by way of inductive coupling. Furthermore, a signal strength of the received test field may be determined. The signal strength can be used to infer the degree of coupling between the primary coil 211 and the secondary coil, and consequently a relative positioning of the primary coil 211 and the secondary coil.

[0067] (2) Image data of a camera 206. As shown in FIG. 2A, the base unit 111 may include a camera 206, which is designed to sense image data of the underfloor of the vehicle 100. In particular, the camera 206 may be arranged on the movable primary coil 211. Furthermore, the camera 206 may be aligned upwardly in order to be able to sense the WPT vehicle unit 102 (and in particular the secondary coil).

[0068] The control unit 205 may be designed to move the primary coil 211 in dependence on the one or more positioning signals. In particular, the control unit 205 may be designed to move the primary coil 211 in such a way that a degree of coupling between the primary coil 211 and the secondary coil is increased (possibly maximized) and/or that an alignment of the primary coil 211 and an alignment of the secondary coil are made to match one another.

[0069] FIG. 2B shows a further structure by way of example of a base unit 111. The base unit 111 includes the primary coil 211, which is fixed on the base unit 111. Furthermore, the base unit 111 includes a multiplicity of rollers and/or wheels 221, by which a movement of the base unit 111 is made possible. In particular, the rollers and/or wheels 221 may be designed to make a movement of the base unit 111 possible in two directions (for example in the x direction and in the y direction) of the horizontal plane. Furthermore, a rotation of the base unit 111 may be made possible by the rollers and/or wheels 221. The control unit 205 may be designed to activate motors in order to move the base unit 111 by means of the rollers and/or wheels 221. In particular, for this purpose one or more positioning signals may be evaluated in order to make a precise positioning of the base unit 111 possible underneath the WPT vehicle unit 102 of the vehicle 100.

[0070] The base unit 111 in FIG. 2b further includes a lighting unit 207. The lighting unit 207 may be designed to emit light in the visible range, and thus display the position of the primary coil 211, and make it detectable for a camera (for example for a camera on the underfloor of the vehicle 100). The primary coil 211 shown in FIG. 2A may also include such a lighting unit 207. Alternatively or additionally, the WPT vehicle unit 102 may also include such a lighting unit 207 in order to make the position of the secondary coil detectable for the camera 206 of the base unit 111.

[0071] Consequently, this document describes a method and a corresponding device for inductively charging a vehicle 110 in which the inductive current-providing coil 211 or a part of this coil 211 is moved under the vehicle 100 by means of a controlling operation, so that an alignment of the current-providing coil 211 (i.e. the primary coil) in relation to the current-receiving coil (i.e. in relation to the secondary coil) is achieved. This has the advantage that the vehicle 100 if need be no longer has to be positioned precisely (in a manual or automatic way) over the base unit 111. Instead, the vehicle 100 can just be positioned relatively approximately by the driver. A precise positioning can then take place (automatically and/or manually) by a movement of the primary coil 211.

[0072] In this case, as shown for example in FIG. 2A, the current-providing coil 211 can be moved by way of an adjusting control 201, 202, 203, 204 within a fixed or installed frame. The current-providing coil 211 can then be moved in the x and y directions, for example by means of a worm drive 201, 202, 203. The rotation about the z axis may take place for example in a mounted manner (on ball-bearing balls 204) and/or by way of a gear drive. The adjusting controls and corresponding drives for the movement of the primary coil 211 can consequently be provided in a low-cost way.

[0073] Alternatively or additionally, the current-providing coil 211 or the base unit 111 may be provided with small wheels and/or rollers 221 and an electrical drive of its own, which are designed for the advancement of the coil 211 (for example directly on the floor of the garage). The primary coil 211 or the base unit 111 may move on the garage floor, for example on 4 small wheels 221. Such driven wheels/rollers 221 can be provided in a low-cost way. Delimiting markings, channels and/or a relief or one or more rails may possibly be provided on the floor in order if need be to delimit the radius of movement of the primary coil 211 or of the base unit 111. Such markings may alternatively or additionally be provided for the vehicle 100, in order at least to facilitate an approximate positioning of the vehicle 100 by the driver.

[0074] The current-providing (lower) coil 211 may as an alternative or in addition be designed with a camera 206, which generates and/or transmits a positioning signal with respect to the positioning of the current-providing coil 211 with respect to the current-receiving coil (i.e. the secondary coil). This may possibly be a wirelessly transmitted video image. The transmission of the image data may take place in particular wirelessly by WLAN to the vehicle 100 and/or to a device fitted in the vehicle and/or to a cell phone/smartphone of the driver and/or to a control unit 205 of the base unit 111.

[0075] Furthermore, a protective mechanism for the sensor, in particular camera, is described. This protective mechanism may be formed as an extendable part of the camera and/or as a protective device of the camera. The protective mechanism is designed to extend a part of the camera, for example the front lens, or to open a flap or shutter, when the approach of a vehicle to be charged is detected. This allows the possibly sensitive sensor to be protected better from environmental conditions. The image data of the secondary coil or the mounting thereof on the vehicle underfloor that is in this way recorded by the camera substantially from “underneath upward” allow the driver of the vehicle 100 to monitor the movement of the primary coil 211 under the vehicle 100. This advantage also applies whenever as an alternative or in addition to a movement of the primary coil 211 the vehicle 100 moves (automatically or manually by the customer). The positioning is consequently facilitated by the use of a camera 206.

[0076] The sensor may be designed in such a way that it can, at least for a time, sense the sensor data from the primary coil and from the secondary coil simultaneously. In this case, a simplified determination of the positioning data is possible. In this example, the sensor may be designed as a wide-angle camera.

[0077] The camera 206 of the primary coil 211 can be provided in a low-cost way (for example a smartphone camera with electronics and app capability and/or WLAN capability). A camera 206 with WLAN may be particularly advantageous and low in cost. The evaluation of the image data and following additional graphics may take place on a computing unit in the vehicle 100 and/or on an electronic device (for example a smartphone) of the driver and/or in the control unit 205 of the base unit 111.

[0078] Alternatively or additionally, a further sensor, in this example a video camera, which is directed downwardly, may be provided on the vehicle underfloor. Such a camera is however disadvantageous, since a vehicle camera can be contaminated relatively quickly. By contrast, the camera 206 proposed here, on the “lower”, current-providing coil 211, is exposed less to the environmental influences, and in addition also does not have to meet any automotive requirements and obtain certifications.

[0079] The lower coil 211 and/or the floor of the charging location (for example the base unit 111) may be provided with a lighting 207, in particular with one or more LEDs, in the visible spectrum and/or infrared spectrum, which may be designed for automatically switching on during the positioning operation. The light may for example be triggered as a sequence of light flashes. The times of the light flashes may be synchronized with the times of the recording by a camera 206. For example, a sequence may be of infrared flashes, which in particular make infrared-reflecting parts of the vehicle 100 easily detectable in the camera image.

[0080] The data transmitted from the charging device 110, 111 (i.e. from the lower current-providing coil 211 with the control unit 205) may include image data, which can be evaluated by use of image processing or object recognition.

[0081] In particular, the image data may be evaluated in order to determine a measure of the coincidence of the positions of the two coils in relation to one another. Alternatively or additionally, one or more parameters of the relative position may be determined. Alternatively or additionally, instructions or commands that can be used for correcting or optimizing the relative position may be determined. Such auxiliary data for the positioning may be generated for example by means of software in the vehicle 100, in a camera 206 and/or in an electronic device (for example smartphone).

[0082] FIG. 3 shows an electronic device 320 given by way of example, for example a smartphone with a touch-sensitive screen. The electronic device 320 has an input unit 321 and an output unit 322. For example, interactive input elements for providing an input unit 321 may be displayed on a touch-sensitive screen. In the example shown, the input unit 321 comprises four cursors, with which an input with respect to a certain direction of movement can be sensed.

[0083] The output unit 322 may for example be a screen. The positioning of the base unit 111 and of the vehicle 100 may be graphically displayed on the output unit 322. In particular, an image 311 of the base unit 111 and an image 300 of the vehicle 100 and also an image 302 of the WPT vehicle unit 102 may be displayed. The displayed images 311, 300, 302 may for example be created on the basis of image data of one or more cameras 206.

[0084] The electronic device 320 may consequently be designed to display the positioning situation between the base unit 111 and the vehicle 100 on an output unit 322. Furthermore, the electronic device 320 may be designed to sense inputs by a user using the input unit 321. The inputs may be devised to move the base unit 111 and/or the vehicle 100. The electronic device 320 may be further designed to generate a control signal for the base unit 111 and/or for the vehicle 100 on the basis of a sensed input, a movement of the base unit 111 and/or of the vehicle 100 that corresponds to the sensed input being brought about by the control signal. The electronic device 320 may be further designed to send the control signal to the base unit 111 and/or the vehicle 100. This allows a movement of the base unit 111 and/or of the vehicle 100 to be remote-controlled by the electronic device 320. A movement brought about by the control signal can be displayed on the output unit 322 (as illustrated by the arrows shown in FIG. 3). This allows if need be a manual positioning between the base unit 111 and the vehicle 100 to be carried out by the electronic device 320, without a driver of the vehicle 100 having to return to the place where the vehicle 100 is parked.

[0085] The positioning operation can consequently be influenced/controlled by a user of the vehicle 100 using the graphic user interface of an electronic device 320 (for example of a smartphone and/or of a display in the vehicle 100). The electronic device 320 (or the operating software running on the electronic device 320) may be designed in such a way that the user only has to specify the resultant direction of movement of the base unit 111 and/or of the vehicle 100, while the trajectory is determined automatically as a compilation of individual movements of the base unit 111 and/or of the vehicle 100. For this purpose, the graphic interface may include an actual object recorded and/or detected by a sensor (for example by a camera 206). In this case, detected objects (for example the base unit 111 and/or the vehicle 100) may be represented by virtual formations/images 311, 300, for example by a special design of an augmentation.

[0086] A user of the electronic device 320 can thus see the movement of the current-providing coil 211 or of the base unit 111 under his/her vehicle 100 (actually or at least partially symbolically displayed) and can influence this movement within the same output unit 322 (i.e. within the same screen) and/or by way of an input unit 321 (for example by way of a rotary knob).

[0087] In a preferred design variant, the current-providing coil 211 or parts of this coil 211 is/are designed to set the optimum position with respect to the secondary coil substantially automatically. The user can see, and at the same time possibly also influence, for example speed up, correct, stop, direct, etc., the movement of the coil 211 on a screen 322. The monitoring or control of the positioning operation may preferably take place by way of a graphic display or by way of a graphic interface (operating symbols, such as for example arrows) and/or by way of the rotation of the electronic device 320, which can be interpreted by way of its own sensor system as a movement request.

[0088] The provision of the remote monitoring and/or remote control described above may also be realized with the aid of an app, which runs on the on-board computer of the vehicle 100 and/or on a smartphone. In particular, at least part of the operating software may run in a computer unit of the vehicle 100.

[0089] The vehicle 100 may include a substantially downwardly aligned sensor, which is designed for the purpose of monitoring the relative position between the primary coil 211 and the secondary coil. In particular, a visualization may be displayed here in the form of a “synthetic image”, created artificially by data of the sensor conditioned by image or signal processing means, on a display of the vehicle 100 and/or on a computer and/or on a smartphone 320 of the user. This may preferably be an infrared LED sensor. The sensor may be designed like a position-sensing unit similar to a computer mouse. The data provided by the sensor may be taken into account as positioning signals in the positioning of the primary coil 211 and/or of the vehicle 100.

[0090] The adjusting control (i.e. in particular the control unit 205) of the base unit 111, which is used for the positioning of the current-providing coil 211, may receive a signal transmitted wirelessly (for example by WLAN) from the vehicle 100, with items of information concerning the already achieved positioning quality or concerning positioning parameters. This allows a control circuit to be closed in order to control the positioning operation. The transmitted signal may be used as a manipulated variable or as an input for determining a manipulated variable of the movement actuators of the base unit 111.

[0091] The control unit 205 may consequently use a control loop in order to position the primary coil 211. The control in this case typically controls the coil position until the predetermined geometrical parameters and/or the predetermined deviation from the maximum possible induction quality and/or the maximum inductive coupling or the adaptation of the optimum energy transfer efficiency is achieved.

[0092] The use of a control circuit, which possibly also takes into account feedback messages from the vehicle 100, makes it possible to monitor, and possibly maximize, directly the degree of coupling to be achieved. This allows the energy efficiency of the vehicle charging to be improved decisively. Such an optimum typically cannot be achieved by an only relatively approximate positioning of the vehicle over the primary coil 211.

[0093] The control unit 205 may be designed to send a signal concerning a successful and/or unsuccessful positioning wirelessly to an electronic device 320 (for example to a cell phone) of a user and/or to the home network of the user. This may obviate the need for monitoring the positioning operation.

[0094] As already explained above, a movement of the primary coil 211 may also be used in combination with an automatically positionable vehicle. For example, the vehicle 100 may be designed to position itself automatically (relatively approximately) in the vicinity of the base unit 111. The movement of the current-providing coil 211 then allows a precise and quick fine positioning to take place (for example by a rotation of the primary coil 211). This allows movements which, for the vehicle 100, can only be carried out with difficulty (for example rotations) to be carried out in an easy and quick way by the primary coil 211. This allows the time expenditure for a driver of the vehicle 100 to be reduced substantially.

[0095] A movement of the vehicle 100 and a movement of the primary coil 211 can be made to match one another. In particular, an overall requirement for relative movement or a deviation from a target position (X, Y, Z, rotation) can be determined for example by the control unit 205, in order to achieve a precise positioning. This overall requirement, i.e. this overall movement, may then be divided into vehicle movement components, which can be carried out by the vehicle 100, and into coil movement components, which can be carried out by the primary coil 211. This allows the positioning operation to be speeded up further. The efficiency of the positioning operation can also be increased.

[0096] FIG. 4 shows a system including a vehicle 100, a charging station 110, 111 and an electronic device 320, which can communicate with one another by way of a network 400, in order to exchange data with respect to the positioning of the primary coil 211 and of the secondary coil. The methods described in this document can be implemented by the vehicle 100, the charging station 110, 111 and/or the electronic device 320 in any desired combination.

[0097] It is pointed out in particular that the methods described in this document can be performed for example by a dedicated system, which is for example arranged at the charging station 110, 111. Furthermore, the vehicle 100 may be designed to perform the methods described in this document. An electronic device 320 (for example a smartphone or a cell phone) may also be designed to perform the methods described in this document.

[0098] The methods described in this document have a large number of advantages: risks and damages for a driver of a vehicle (for example damages to property and personal injuries) that could arise in the case of an automatically moved vehicle are avoided. Possibly high requirements for vehicle-based solutions (ASIL development with the requisite functional safety) are avoided. There are no longer complex technical dependences on vehicle systems. In particular, there are no longer numerous requirements for special equipment and the architecture of a vehicle, resulting in cost advantages. There are no backward compatibility restrictions. In particular, a vehicle-external solution typically has increased flexibility, since the charging device can also be further developed independently of the development process of a vehicle. Consequently, substantial reductions of the development time and development costs of vehicles are obtained. The solution described in this document is also quite acceptable for public areas. In particular, the ability to obtain approval is facilitated in various ways, since the system is independent of the Vienna Convention, of homologation procedures, etc. The method described in this document allows the time expenditure for the positioning of the coils to be reduced. The preparation for the charging operation can proceed more quickly. Furthermore, no laborious maneuvering operations by a driver are required. The use of smaller parking spaces/garages is also made possible, since the primary coil can be moved more flexibly than a vehicle. Furthermore, increased user friendliness can be provided by the user interface described.

[0099] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.