Abstract
A method for orienting a power receiving coil of a vehicle relative to a power emitting coil of a wireless charging system for a vehicle. The method includes detecting a positioning of the vehicle at a charging location in which the power receiving coil detects reception of electromagnetic radiation emitted from the power emitting coil, performing a calibration sequence in which the orientation of the power receiving coil and/or the power emitting coil is varied according to a predetermined scheme, while registering the electromagnetic radiation reception of the power receiving coil, in response to the calibrations sequence, determining a desired relative orientation including relative angle between the power receiving coil and the power emitting coil for which the electromagnetic radiation reception of the power receiving coil is in a top range of the registered electromagnetic radiation reception.
Claims
1. A method for orienting a power receiving coil of a vehicle relative to a power emitting coil of a wireless charging system for a vehicle, the method comprising: detecting a positioning of the vehicle at a charging location in which the power receiving coil detects reception of electromagnetic radiation emitted from the power emitting coil, performing a calibration sequence in which the orientation of the power receiving coil and/or the power emitting coil is varied according to a predetermined scheme, while registering the electromagnetic radiation reception of the power receiving coil, in response to the calibrations sequence, determining a desired relative orientation including relative angle between the power receiving coil and the power emitting coil for which the electromagnetic radiation reception of the power receiving coil is in a top range of the registered electromagnetic radiation reception, positioning the power receiving coil relative to the power emitting coil according to the desired relative orientation.
2. The method according to claim 1, wherein the predetermined scheme comprises a plurality of different orientations of the power receiving coil and/or the power emitting coil.
3. The method according to claim 1, wherein the predetermined scheme comprises variations of the relative angle between the power receiving coil and the power emitting coil, and the calibration sequence comprises tilting or rotating at least one of the power receiving coil and the power emitting coil in response to such predetermined scheme.
4. The method according to claim 3, wherein the predetermined scheme comprises variations of the relative angle between the power receiving coil and the power emitting coil in at least two directions.
5. The method according to claim 3, wherein the predefined scheme comprises variations of the inclination of the power receiving coil relative to a first reference frame, and the calibration sequence comprises using the vehicle suspension system to achieve such variations of the inclination of the power receiving coil.
6. The method according to claim 3, wherein the predefined scheme comprises variations of the inclination of the power emitting coil relative to a second reference frame, and the calibration sequence comprises pivoting the power emitting coil around a pivot point to achieve such variations of the inclination of the power emitting coil.
7. The method according to claim 1, wherein positioning the power receiving coil of the vehicle relative to the power emitting coil of the wireless charging system according to the desired relative orientation is performed subsequent to performing the calibration sequence and determining the desired relative orientation between the power receiving coil and the power emitting coil.
8. The method according to claim 1, wherein the calibration sequence is performed to include a global maximum of the electromagnetic radiation reception of the power receiving coil with regards to the relative angle between the power receiving coil and the power emitting coil.
9. The method according to claim 1, further comprising holding the power receiving coil in the desired relative orientation as a fixed position relative to the power emitting coil for charging the vehicle.
10. A wireless power supply device for a vehicle, the wireless power supply device comprising: a power receiving coil for a vehicle being configured to receive electromagnetic radiation emitted from a power emitting coil of a wireless charging system, a positioning arrangement configured to orient the power receiving coil relative to the power emitting coil; a control unit connected to the positioning arrangement, the control unit being configured to control a calibration sequence in which the orientation of the power receiving coil and/or the power emitting coil is varied according to a predetermined scheme by means of the positioning arrangement, while registering the electromagnetic radiation reception of the power receiving coil, wherein the control unit is further configured to, in response to the calibration sequence, determine a desired relative orientation including relative angle between the power receiving coil and the power emitting coil for which the electromagnetic radiation reception of the power receiving coil is in a top range of the registered electromagnetic radiation reception, and to, by means of the positioning arrangement, position the power receiving coil relative to the power emitting coil according to the desired relative orientation.
11. The wireless power supply device according to claim 10, wherein the positioning arrangement is configured to tilt the power receiving coil relative to the power emitting coil in order to vary the relative angle between the power receiving coil and the power emitting coil.
12. The wireless power supply device according to claim 11, wherein the positioning arrangement comprises the vehicle suspension system to achieve variations of the inclination of the power receiving coil relative to the power emitting coil.
13. A wireless charging system for a vehicle, the wireless charging system comprising: a power emitting coil and a wireless power supply device according to claim 10, the power receiving coil of the wireless power supply device being configured to receive electromagnetic radiation emitted from the power emitting coil.
14. A computer program comprising program code means for performing the method of claim 1, when the program is run on a computer.
15. A vehicle comprising a wireless power supply device according to claim 10.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0061] With reference to the appended drawings, below follows a more detailed description of embodiments of the invention cited as examples. In the drawings:
[0062] FIG. 1 is a side schematic view of a vehicle in accordance with an example embodiment of the invention;
[0063] FIGS. 2A-2C are schematic perspective views of wireless charging system comprising a power emitting coil and a wireless power supply device including a power receiving coil configured to receive electromagnetic radiation emitted from the power emitting coil in accordance with an example embodiment of the invention;
[0064] FIGS. 3A-3C are schematic perspective views of yet another wireless charging system comprising a power emitting coil and a power receiving coil in accordance with an example embodiment of the invention;
[0065] FIG. 4A is a perspective view of a wireless power supply device including a power receiving coil configured to receive electromagnetic radiation emitted from the power emitting coil in accordance with an example embodiment of the invention;
[0066] FIG. 4B is a perspective view of yet another wireless charging system comprising a power emitting coil and a power receiving coil in accordance with an example embodiment of the invention; and
[0067] FIG. 5 is a flowchart illustrating the steps of method in accordance with one example embodiment of the invention.
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION
[0068] With reference to FIG. 1, a vehicle 1, here embodied as a heavy duty truck 1, is disclosed for which a method, a wireless charging system 10, and/or a wireless power supply device 40 of a kind disclosed in the present invention are advantageous. However, the method, wireless charging system 10, or a wireless power supply device 40 may as well be implemented in other types of vehicles, such as in busses, light-weight trucks, passenger cars, marine applications (e.g. in a vessel) etc. The vehicle 1 is an electric vehicle, such as a full electric vehicle or a hybrid, comprising at least one electric machine 15, a rechargeable energy storage system, RESS, 30 comprising three energy storage devices 31, 32, 33, typically batteries, the RESS 30 being arranged and configured to power the electric machine 15. Moreover, the vehicle 1 comprises an auxiliary load 20 arranged and configured for being powered by the RESS 30, the auxiliary load 20 being e.g. a heater or a HVAC system. Thus, the RESS 30 is arranged and configured to supply at least two different loads 15, 20 with electric power. The vehicle 1 further comprises an undercarriage 2 comprising the underside of the vehicle 1, wheels 3 suspended by a vehicle suspension system 5, here indicated by a separate suspension units 5a for each wheel 3. The vehicle suspension system is configured to allow relative motion between the vehicle 1 (and undercarriage 2) and the wheels 3 of the vehicle 1. The vehicle 1 typically further comprises other parts of the powertrain such as transmission and drive shafts (not shown in detail).
[0069] As seen in FIG. 1, the RESS 30 is connected to an electrical energy source, here being a power grid, or grid 80, via a wireless charging system 10. The wireless charging system 10 comprises a wireless power supply device 40 including at least a power receiving coil 42, and comprises a power emitting coil 52, the power receiving coil 42 being configured to receive electromagnetic radiation emitted from the power emitting coil 52. In more detail, the power emitting coil 52 is configured to emit electromagnetic radiation, and the power receiving coil 42 is configured to receive electromagnetic radiation emitted from the power emitting coil 52. The electromagnetic radiation may typically refer to the electromagnetic field induced by the power emitting coil 52, which electromagnetic field the power receiving coil 42 can utilize for power/current generation. Typically, for such power transmission to occur, the power receiving coil 42 must be within an electromagnetic radiation reception distance from the power emitting coil 52. The wireless charging system 10 may be referred to as an inductive charging system. The power receiving coil 42 and the power emitting coil 52 will be further described with reference to FIGS. 2-4.
[0070] In FIG. 1, the power emitting coil 52 is powered by the grid 80 via an energy transfer means 90, typically a cable for transferring electrical energy to the power emitting coil 52 via an inlet box 54. Thus, the wireless charging system 10 is configured to charge the energy storage devices 31, 32, 33, or batteries 31, 32, 33. The vehicle 1 further comprises a control unit 17 configured to control a calibration sequence of the power receiving coil 42 relative to the power emitting coil 52 of the wireless charging system 10, as will be described in the following.
[0071] Turning to FIGS. 2A-2C illustrating schematic views of a wireless charging system 110, e.g. being implemented as the wireless charging system 10 of vehicle 1 in FIG. 1. The wireless charging system 110 comprises a power emitting coil 152 and a wireless power supply device 140 including at least a power receiving coil 142, the power receiving coil 142 of being configured to receive electromagnetic radiation emitted from the power emitting coil 152. The wireless power supply device 140 is partly schematically illustrated and comprises a control unit 117 and a positioning arrangement 144 (only shown in FIG. 2A, but implicitly included in FIGS. 2B-2C). The positioning arrangement 144 of FIG. 2A comprises at least the vehicle suspension system 105, such as e.g. the vehicle suspension system 5 of vehicle 1 of FIG. 1. The power receiving coil 142, here embodied as a planar power receiving coil 142, is attached to the undercarriage of the vehicle by means of an attachment means 143. For example, the attachments means 143, e.g. being a fastener or a connecting rod, is providing a fixed attachment to the undercarriage of the vehicle. Thus, the power receiving coil 142 is movable together with the attachment means 143 and the undercarriage of the vehicle.
[0072] The positioning arrangement 144 is configured to orient the power receiving coil 142 relative to the power emitting coil 152. Thus, the positioning arrangement 144 may further be considered to comprise the attachments means 143. In FIG. 2A, the relative orientation of the power receiving coil 142 and the power emitting coil 152 is controlled by the control unit 117 connected to the positioning arrangement 144, or rather the vehicle suspension system 105. The control unit 117 is configured to control a calibration sequence in which the orientation of the power receiving coil 142 is varied according to a predetermined scheme by means of the positioning arrangement 144. Thus, the vehicle suspension system 105 may achieve such variations of the orientation of the power receiving coil 142 as the attachments means 143 is attached to the undercarriage of the vehicle. In other words, the vehicle suspension system is used for tilting the power receiving coil 142 relative to a first reference frame, the first reference frame being e.g. the power emitting coil 152 (but may as well be a reference frame of the ground at which the vehicle is parked). The reference frame may e.g. be a plane, such as an xy-plane in a Cartesian coordinate system. Thus, the vehicle suspension system 105 may be used to vary the suspension of the wheels, and thereby adjusting the distance of the undercarriage and the ground at which the vehicle is parked. By adjusting the suspension of the wheels differently, e.g. differently between the wheels at the front of vehicle and wheels at the back of the vehicle, or differently between the wheels at one side of the vehicle compared to an opposite side of the vehicle, the undercarriage of the vehicle, and hence the power receiving coil 142, may be tilted. Hereby, the power receiving coil 142 will be oriented differently corresponding to the level of the suspension of the vehicle. Thus, the orientation of the power receiving coil 142 is varied by varying the inclination of the power receiving coil 142 relative to the first reference frame, as can be seen in FIGS. 2B and 2C. Stated differently, the positioning arrangement 144 is configured to tilt or rotate the power receiving coil 142 relative to the power emitting coil 152 in order to vary the relative angle α between the power receiving coil 142 and the power emitting coil 152 (only shown in FIG. 2B). That is, the vehicle suspension 105 is used to achieve variations of the inclination of the power receiving coil 142 relative to the power emitting coil 152, and thereby at least partly perform the calibration sequence. Thus, the predefined scheme comprises variations of the inclination of the power receiving coil 142 relative to the first reference frame, and the calibration sequence comprises using the vehicle suspension system 105 to achieve such variations of the inclination of the power receiving coil 142. According to at least one example embodiment, the orientation of the power emitting coil 152 is fixed in FIGS. 2A-2C, and/or the power emitting coil 152 lacks the functionality of varying its orientation.
[0073] During the calibration sequence, the control unit 117 is configured to register the electromagnetic radiation reception of the power receiving coil 142. The control unit 117 is further configured to, in response to the calibration sequence, determine a desired relative orientation including relative angle α between the power receiving coil 142 and the power emitting coil 152 for which the electromagnetic radiation reception of the power receiving coil 142 is in a top range of the registered electromagnetic radiation reception, and to, by means of the positioning arrangement 144 (i.e. here being the vehicle suspension system 105 and the attachment means 143), position the power receiving coil 142 relative to the power emitting coil 152 according to the desired relative orientation. Moreover, the control unit 117 may be configured to determine whether or not the power receiving coil 142 is within an electromagnetic radiation reception distance from the power emitting coil 152, prior to performing the calibration sequence.
[0074] Turning to FIGS. 3A-3C, illustrating schematic views of a wireless charging system 210, e.g. being implemented as the wireless charging system 10 of vehicle 1 in FIG. 1. The wireless charging system 210 comprises a power receiving coil 242, e.g. the same as the power receiving coil 142 of FIGS. 2A-2C, and a power emitting coil 252. However, according to at least one example embodiment, the orientation of the power receiving coil 242 is fixed in FIGS. 3A-3C, and/or the power receiving coil 242 lacks the functionality of varying its orientation. The power emitting coil 252 is e.g. a planar power emitting coil 252. The power receiving coil 242 is configured to receive electromagnetic radiation emitted from the power emitting coil 252. Instead of varying the orientation of the power receiving coil 142, 242 as described with reference to FIGS. 2A-2C, the orientation of the power emitting coil 252 is varied in FIGS. 3A-3C. However, the configuration and embodiment of the wireless power supply device 140 and the power receiving coil 142 of FIGS. 2A-2C may according to at least one example embodiment be combined with the embodiment of FIGS. 3A-3C. In FIG. 3A, the wireless charging system 210 is partly schematically illustrated and comprises a control unit 217 (only shown in FIG. 3A, but implicitly included in the FIGS. 3B-3C) and a positioning arrangement 254 The positioning arrangement 254 of FIG. 3A comprises a rotatable pivot point 256 being pivotally attached to the power emitting coil 252, and used for tilting or rotating the power emitting coil 252 relative to a second reference frame. The second reference frame may e.g. be a reference frame of the ground at which the vehicle is parked. The second reference frame may e.g. be a plane, such as an xy-plane in a Cartesian coordinate system. Thus, corresponding to the predefined scheme and the calibration sequence described with reference to FIGS. 2A-2C, the predefined scheme may comprises variations of the inclination of the power emitting coil 252 relative to the second reference frame, and the calibration sequence may comprise pivoting the power emitting coil 252 around the rotatable pivot point 256 to achieve such variations of the inclination of the power emitting coil 252. In more detail, the rotatable pivot point 256 may be used to vary the inclination between the power emitting coil 252 and the second reference frame in at least two directions, or in three directions, the directions being e.g. perpendicular directions in a Cartesian coordinate system, i.e. directions in the x-axis, y-axis and z-axis. Hereby, the power emitting coil 252 can be oriented differently corresponding to how the power emitting coil 252 is tilted or rotated in relation to the rotatable pivot point 256, as shown in FIGS. 3B and 3C. Thus, the orientation of the power emitting coil 252 is varied by varying the inclination of the power emitting coil 252 relative to the second reference frame. That is, the rotatable pivot point 256 is used to at least partly perform the calibration sequence. As seen in FIGS. 3A-3B, the power emitting coil 252 is arranged, or attached, to the rotatable pivot point 256 such that it can be inclined relative to the second reference frame.
[0075] Correspondingly to the control unit 117 of FIG. 2A, the control unit 217 of FIG. 3A is configured to register the electromagnetic radiation reception of the power receiving coil 242 (this may e.g. be achieved by that the electromagnetic radiation reception of the power receiving coil 242 is wirelessly transferred to the control unit 217). The control unit 217 is further configured to, in response to the calibration sequence, determine a desired relative orientation including relative angle α (only shown in FIG. 3B) between the power receiving coil 242 and the power emitting coil 252 for which the electromagnetic radiation reception of the power receiving coil 242 is in a top range of the registered electromagnetic radiation reception, and to, by means of the positioning arrangement 254 (i.e. here being rotatable pivot point 256 and/or any integrated actuators used to control it), position the power emitting coil 252 relative to the power receiving coil 242 according to the desired relative orientation. Moreover, the control unit 217 may be configured to determine whether or not the power receiving coil 242 is within an electromagnetic radiation reception distance from the power emitting coil 252, prior to performing the calibration sequence.
[0076] Instead of varying the orientation of the power emitting coil 252 with the positioning arrangement 254 comprising a rotatable pivot point 256 as in FIG. 3A, the orientation of the power receiving coil may be varied by means of such positioning arrangement as shown in FIG. 4A. Here, the positioning arrangement 344 comprises a corresponding rotatable pivot point 346 being pivotally attached to the power receiving coil 342. The positioning arrangement 344 and the rotatable pivot point 346 are thus used for tilting or rotating the power receiving coil 342 relative to the first reference frame, e.g. by being instructed to do so in a calibration sequence by the control unit 317. Thus, the function thereof corresponds to that described with reference to FIGS. 3A-3C and is not repeated here again.
[0077] Another embodiment of a wireless charging system 410 is shown in FIG. 4B. The wireless charging system 410 comprises a power receiving coil 442 and a power emitting coil 452, e.g. being planar coils 442, 452. The power receiving coil 442 is configured to receive electromagnetic radiation emitted from the power emitting coil 452. In FIG. 4B both the power receiving coil 442 and a power emitting coil 452 are configured to vary the orientation of the power receiving coil 442 and a power emitting coil 452, respectively, by means of actuators 444, 454. The actuators 444, 454 are configured to tilt or rotate the power receiving coil 442 and a power emitting coil 452, respectively about a fixed pivot point 446, 456, respectively. For example, the power emitting coil 452 is arranged to move around the fixed pivot point 456 by means of the actuators 454 connected to the power emitting coil 452. Correspondingly, the power receiving coil 442 is arranged to move around the fixed pivot point 446 by means of the actuators 444 connected to the power receiving coil 442. Thus, the orientation of the power emitting coil 452 may be varied by varying the inclination of the power emitting coil 452 relative to the second reference frame, as described with reference to FIGS. 3A-3C, and the orientation of the power receiving coil 442 may be varied by varying the inclination of the power receiving coil 442 relative to the first reference frame, as described with reference to FIGS. 2A-2C. As for the earlier described embodiments, a control unit may be configured to perform a calibration sequence for varying the relative orientation of the power receiving coil 442 and the power emitting coil 452. Such control unit is then typically further configured to, in response to the calibration sequence, determine a desired relative orientation including relative angle between the power receiving coil 442 and the power emitting coil 452 for which the electromagnetic radiation reception of the power receiving coil 442 is in a top range of the registered electromagnetic radiation reception, and to, by means of the positioning arrangement (i.e. here being actuators 444, 454), position the power emitting coil 452 relative to the power receiving coil 442 according to the desired relative orientation.
[0078] However, it should be noted that only one of the power receiving coil 442 and the power emitting coil 452 may be controlled to vary its orientation as described with reference to FIG. 4B. Thus, the power receiving coil in the wireless charging system 410 may e.g. be the same as the power receiving coil 142 of FIGS. 2A-2C, or the power receiving coil 242 of FIGS. 3A-3C, or the power emitting coil in the wireless charging system 410 may e.g. be the same as the power emitting coil 152 of FIGS. 2A-2C, or the power emitting coil 252 of FIGS. 3A-3C.
[0079] Turning to the flowchart of FIG. 5, schematically illustrating steps for orienting a power receiving coil of a vehicle relative to a power emitting coil of a wireless charging system for a vehicle, such as the power receiving coils and power emitting coils described with reference to FIGS. 1-4B.
[0080] In a first step S10, a positioning of the vehicle at a charging location in which the power receiving coil detects reception of electromagnetic radiation emitted from the power emitting coil is detected.
[0081] At, or during, the first step S10, the power receiving coil is distanced from the power emitting coil by at least a first vertical distance d1. Depending on the efficiency of the electromagnetic radiation reception at the first vertical distance d1, the power receiving coil may be repositioned relative the power emitting coil in at least the vertical direction. After such repositioning, the power receiving coil is typically distanced from the power emitting coil by at least a second vertical distance d2, the second vertical distance d2 being smaller than the first vertical distance d1. Such movement in the at least vertical direction may e.g. be a movement in the vertical direction (parallel to the gravitational direction, i.e. either in the gravitational direction or opposite the gravitational direction).
[0082] In a second step S20, a calibration sequence in which the orientation of the power receiving coil and/or the power emitting coil is varied according to a predetermined scheme, while registering the electromagnetic radiation reception of the power receiving coil, is performed. The predetermined scheme typically comprises a plurality of different orientations of the power receiving coil and/or the power emitting coil. For example, the predetermined scheme comprises variations of the relative angle between the power receiving coil and the power emitting coil, and the calibration sequence comprises tilting or rotating at least one of the power receiving coil and the power emitting coil in response to such predetermined scheme, as described with reference to FIGS. 2A-4B. The predetermined scheme may thus comprise variations of the relative angle between the power receiving coil and the power emitting in at least two directions, e.g. in three directions. Moreover, the predefined scheme may comprise variations of the inclination of the power receiving coil relative to a first reference frame. Additionally, the calibration sequence may comprise using the vehicle suspension system to achieve such variations of the inclination of the power receiving coil, as for example described with reference to FIGS. 2A-2C. Additionally, or alternatively, the predefined scheme may comprise variations of the inclination of the power emitting coil relative to a second reference frame. Here, the calibration sequence comprises pivoting the power emitting coil around a rotatable pivot point to achieve such variations of the inclination of the power emitting coil, as for example described with reference to FIGS. 3A-3C.
[0083] In a third step S30, in response to the calibrations sequence, a desired relative orientation including relative angle between the power receiving coil and the power emitting coil for which the electromagnetic radiation reception of the power receiving coil is in a top range of the registered electromagnetic radiation reception is determined
[0084] In a fourth step S40, the power receiving coil is positioned relative to the power emitting coil according to the desired relative orientation. The step S40 of positioning the power receiving coil of the vehicle relative to the power emitting coil of the wireless charging system according to the desired relative orientation is typically performed subsequent to the step S20 of performing the calibration sequence and determining the desired relative orientation between the power receiving coil and the power emitting coil. According to at least one example embodiment, the calibration sequence is performed to include a global maximum of the electromagnetic radiation reception of the power receiving coil with regards to the relative angle between the power receiving coil and the power emitting coil. Thus, the step S40 of positioning the power receiving coil of the vehicle relative to the power emitting coil of the wireless charging system according to the desired relative orientation comprises positioning the power receiving coil relative to the power emitting coil such that a global maximum of the electromagnetic radiation reception of the power receiving coil is achieved.
[0085] In a fifth step S50, the power receiving coil is held in the desired relative orientation as a fixed position relative to the power emitting coil for charging the vehicle.
[0086] It should be noted that the naming of the steps not necessarily, but might according to at least one example embodiment, relate to the order in which the steps are carried out. Thus, the order of the steps may be different than that explained here. Moreover, the control unit 17 of FIG. 1 (or any of the other control units 117, 217, 317) may be configured to carry out one or several of the steps S10-S50.
[0087] It should be noted that the control unit 17, 117, 217, 317 may instead of being on-vehicle based, be arranged off-board, e.g. on the same side as the power emitting coil. However, such configuration would typically include wireless communication with another control unit arranged on-board the vehicle 1.
[0088] It is to be understood that the present invention is not limited to the embodiments described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims.
[0089] Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed inventive concept, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
