METHOD FOR REPOSITIONING A POWER RECEIVING COIL OF A VEHICLE

Abstract

The present invention relates to a method for repositioning a power receiving coil (122) of a vehicle (1) relative a power emitting coil (222) of a wireless charging system (200, 200′). The method comprising the steps of: detecting (S1) a positioning of the vehicle at a charging location (50) in which the power receiving coil detects reception of electromagnetic radiation emitted from the power emitting coil, determining (S2) whether or not the efficiency of the electromagnetic radiation reception of the power receiving coil achieves a pre-set criteria, repositioning (S3) the power receiving coil relative the power emitting coil in at least the vertical direction (z) in response to determining that the efficiency of the electromagnetic radiation reception does not fulfil the pre-set criteria.

Claims

1. A method for repositioning a power receiving coil of a vehicle relative a power emitting coil of a wireless charging system, the method comprising the steps of: 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, determining whether or not the efficiency of the electromagnetic radiation reception of the power receiving coil achieves a pre-set criteria, repositioning the power receiving coil relative the power emitting coil in at least the vertical direction in response to determining that the efficiency of the electromagnetic radiation reception does not fulfil the pre-set criteria.

2. The method according to claim 1, further comprising the step of repeating the step of determining, and the step of repositioning, until the efficiency of the electromagnetic radiation reception of the power receiving coil fulfils the pre-set criteria.

3. The method according to claim 1, wherein in the step of detecting, the power receiving coil is distanced from the power emitting coil by at least a first vertical distance, and wherein the step of repositioning results in that the power receiving coil is distanced from the power emitting coil by at least a second vertical distance, the second vertical distance being smaller or larger than said first vertical distance.

4. The method according to claim 1, wherein the step of repositioning includes vertically moving the undercarriage of the vehicle to which the power receiving coil is attached to.

5. The method according to claim 4, wherein the step of vertically moving the undercarriage of the vehicle is carried out by adjusting the suspension of the vehicle.

6. The method according to claim 1, wherein the power receiving coil is movably attached to the undercarriage of the vehicle, and the step of repositioning includes vertically moving the power receiving coil relative the undercarriage of the vehicle.

7. The method according to any one of the preceding claims claim 1, wherein the step of repositioning includes vertically moving the power emitting coil.

8. The method according to claim 1, further comprising the step of holding the power receiving coil in a fixed position relative the power emitting coil in response to determining that the efficiency of the electromagnetic radiation reception fulfils the pre-set criteria.

9. A wireless power supply device for a vehicle, the wireless power supply device comprising: a power receiving coil configured to receive electromagnetic radiation emitted from a power emitting coil, a control unit connected to the power receiving coil, the control unit being configured to determine whether or not the efficiency of electromagnetic radiation reception of the power receiving coil achieves a pre-set criteria, a re-positioning arrangement configured to, in response to the control unit determining that the efficiency of the electromagnetic radiation reception does not fulfil the pre-set criteria, at least vertically reposition the power receiving coil relative the power emitting coil.

10. The wireless power supply device according to claim 9, wherein the control unit is configured to determine whether or not the power receiving coil is within an electromagnetic radiation reception distance from the power emitting coil.

11. The wireless power supply device according to claim 9, wherein the control unit is configured to repeat the step of determining whether or not the efficiency of the electromagnetic radiation reception of the power receiving coil achieves a pre-set criteria after each repositioning of the re-positioning arrangement, until the control unit determines that the efficiency of the electromagnetic radiation reception of the power receiving coil fulfils the pre-set criteria.

12. The wireless power supply device according to claim 9, wherein the re-positioning arrangement is configured to, in response to the control unit determining that the efficiency of the electromagnetic radiation reception does not fulfil the pre-set criteria, move the power receiving coil vertically closer to, or further away from, the power emitting coil.

13. A vehicle comprising a wireless power supply device according to claim 9.

14. The vehicle according to claim 13, wherein the power receiving coil is attached to an undercarriage of the vehicle, and the re-positioning arrangement is configured to vertically move the undercarriage of the vehicle in order to vertically move the power receiving coil.

15. The vehicle according to claim 13, wherein at least a part of the re-positioning arrangement is arranged in between the power receiving coil and the undercarriage of the vehicle such that the receiving coil is movably attached to the undercarriage of the vehicle, and wherein the re-positioning arrangement is configured to vertically move the power receiving coil relative the undercarriage of the vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0066] With reference to the appended drawings, below follows a more detailed description of embodiments of the invention cited as examples.

[0067] In the drawings:

[0068] FIG. 1 is a side schematic view of a vehicle and a wireless charging system in accordance with an example embodiment of the invention;

[0069] FIG. 2 is a detailed view of wireless charging system and a wireless charging device, in which the vertical distance between a power emitting coil and a power receiving coil is varied in accordance with an example embodiment of the invention;

[0070] FIG. 3 is a detailed view of a wireless charging system and a wireless charging device, in which the vertical distance between a power emitting coil and a power receiving coil is varied in accordance with another example embodiment of the invention; and

[0071] FIG. 4 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

[0072] With reference to FIG. 1 a vehicle 1, here embodied as a heavy duty truck 1, is disclosed for which a wireless charging system 200 and a wireless charging device 120 of a kind disclosed in the present disclosure is advantageous. However, wireless charging system 200 and a wireless charging device 120 may as well be implemented in other types of vehicles, such as in busses, light-weight trucks, passenger cars, marine applications etc. The vehicle 1 may be an electric vehicle, such as a full electric vehicle or a hybrid, comprising a battery 110 and a motor or engine 100, wherein the engine 100 is at least partly powered by the battery 110. The wireless charging system 200 and a wireless charging device 120 are configured to charge the battery 110. The vehicle in FIG. 1 further comprises an undercarriage 5 comprising the underside of the vehicle 1, and a suspension arrangement 7, or suspension 7, arranged to configured to allow relative motion between the vehicle 1 (and undercarriage 5) and the tires or wheels of the vehicle 1.

[0073] In FIG. 1, the wireless charging system 200 comprises a wireless charging device 120 including a power receiving coil 122, and a power emitting coil 222. The power emitting coil 222 is configured to emit electromagnetic radiation, and the power receiving coil 122 is configured to receive electromagnetic radiation emitted from the power emitting coil 222. The electromagnetic radiation may typically refer to the electromagnetic field induced by the power emitting coil 222, which electromagnetic field the power receiving coil can utilize for power/current generation. Typically, for such power transmission to occur, the power receiving coil 122 must be within an electromagnetic radiation reception distance from the power emitting coil 222. As seen in FIG. 1, the power emitting coil 222 is powered by a power source 224, e.g. the electrical grid or a battery. The wireless charging system 200 may be referred to as an inductive charging system.

[0074] In FIG. 1, the power receiving coil 122 is attached to the undercarriage 5 of the vehicle 1 by means of an attaching device 9. Moreover, the wireless charging device 120 comprises a re-positioning arrangement 130 configured to, at least vertically reposition the power receiving coil 122 relative the power emitting coil 222. The movement in the vertical direction Z is in FIG. 1 parallel to the gravitational direction g. In the embodiment of FIG. 1, two alternatives of how the re-positioning arrangement 130 is integrated into the vehicle is shown. In a first example embodiment, the re-positioning arrangement 130 comprises, or is integrated into, the attaching device 9, and is thus attached to the undercarriage 5 of the vehicle 1. In this embodiment, the re-positioning arrangement 130 is arranged to move the power receiving coil 122 relative the undercarriage 5 in order to vary the distance between the power receiving coil 122 and the power emitting coil 222 (which is further described with reference to FIG. 2). In a second example embodiment, the re-positioning arrangement 130 comprises, or is integrated into, the suspension 7 of the vehicle 1. In this embodiment, the attaching device 9 is typically providing a firm, non-flexible, attachment between the power receiving coil 122 and the undercarriage 5 of the vehicle 1 (for example, the attaching device 9 may form a part or portion of the undercarriage 5).

[0075] The wireless charging system 200, possibly via the wireless charging device 120, further comprises a control unit 3 (which may be an electrical control unit, ECU, of the vehicle 1) connected to the power receiving coil 122. The control unit is configured to determine whether or not the efficiency of electromagnetic radiation reception of the power receiving coil 122 achieves a pre-set criteria (which is further explained with reference to FIG. 4). The control unit 3 is typically configured to, in response to determining that the efficiency of the electromagnetic radiation reception does not fulfil or meet the pre-set criteria, instruct the re-positioning arrangement 130 to at least vertically reposition the power receiving coil 122 relative the power emitting coil 222. Moreover, the control unit 3 may be configured to determine whether or not the power receiving coil 122 is within an electromagnetic radiation reception distance from the power emitting coil 222. For example, if the vehicle 1 is positioned at a charging location 50, but in which the control unit 3 does not receive any indication or signal related to a received electromagnetic radiation by the power receiving coil 122, the control unit 3 may instruct the vehicle 1 to move, e.g. forwards or backwards until the control unit 3 receives such signal, or is otherwise stopped (e.g. due to safety concerns). As an alternative, the control unit 3 may instruct the re-positioning arrangement 130 to at least vertically reposition the power receiving coil 122 relative the power emitting coil 222, until the control unit 3 receives such signal, or is otherwise stopped (e.g. due to physical constraints of the re-positioning arrangement 130 and/or coil design).

[0076] It should be noted that the control unit 3 may instead of being on-vehicle based, be arranged off-board, e.g. on the same side as the power emitting coil 222. However, such configuration would typically include wireless communication with another control unit arranged on-board the vehicle 1.

[0077] Turning to the flowchart of FIG. 4, schematically illustrating steps of a method for repositioning a power receiving coil of a vehicle, such as the power receiving coil 122 of vehicle 1 in FIG. 1, relative a power emitting coil or a wireless charging system, such as the power emitting coil 222 or wireless charging system 200 of FIG. 1.

[0078] In a first step S1, 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.

[0079] At, or during, the first step S1, the power receiving coil is distanced from the power emitting coil by at least a first vertical distance d1, which e.g. is shown in FIG. 2.

[0080] In a second step S2, whether or not the efficiency of the electromagnetic radiation reception of the power receiving coil achieves a pre-set criteria is determined.

[0081] The second step S2 may e.g. be carried out by receiving data information related to the pre-set criteria (e.g. by a previous determination of the efficiency of the electromagnetic radiation reception, or by a predicted or expected efficiency of the electromagnetic radiation reception based on e.g. known characteristic of the emitted electromagnetic radiation), by measuring received electromagnetic radiation by the power receiving coil, calculating the efficiency of the electromagnetic radiation reception by utilizing the measured received electromagnetic radiation and known characteristic of the emitted electromagnetic radiation, and comparing calculated efficiency with the pre-set criteria, e.g. the predicted or expected efficiency.

[0082] In a third step S3, in response to determining that the efficiency of the electromagnetic radiation reception does not fulfil the pre-set criteria, the power receiving coil is repositioned relative the power emitting coil in at least the vertical direction.

[0083] The third step S3 results in that the power receiving coil is distanced from the power emitting coil by at least a second vertical distance d2. The second vertical distance d2 is either smaller than the first vertical distance d1, or larger than the first vertical distance d1, which e.g. is shown in FIG. 2.

[0084] The movement in the at least vertical direction may e.g. be a movement parallel to the gravitational direction, i.e. either in the gravitational direction or opposite the gravitational direction. As stated previously, the movement may be carried out by the power receiving coil and/or the power emitting coil.

[0085] According to at least one example embodiment, the third step S3 includes vertically moving the undercarriage of the vehicle to which the power receiving coil is attached to. Thus, the undercarriage is moved in at least the vertical direction in order to reposition the power receiving coil relative the power emitting coil. The power receiving coil is in this embodiment typically attached, such as e.g. firmly attached or rigidly attached, to the undercarriage of the vehicle, such that the power receiving coil and the undercarriage move in unison. The vertical movement of the undercarriage of the vehicle may e.g. be carried out by adjusting the suspension 7, or suspension arrangement 7, of the vehicle. Such suspension is typically arranged and configured to allow for a relative movement between the undercarriage and the wheels or tires of the vehicle.

[0086] According to at least one alternative example embodiment, the power receiving coil is movably attached to the undercarriage of the vehicle, and the third step S3 includes vertically moving the power receiving coil relative the undercarriage of the vehicle. This may e.g. be carried out by the re-positioning arrangement 130 described with reference to FIG. 1 and FIG. 2. Thus, in such embodiments, the power receiving coil is arranged and configured to allow for a relative movement between the undercarriage of the vehicle and the power receiving coil.

[0087] According to at least yet one alternative example embodiment, the third step S3 includes vertically moving the power emitting coil.

[0088] In such embodiments, at least the power emitting coil is arranged and configured to be moved at least in the vertical direction.

[0089] In a fourth step S4, the second step S2, and the third step S3, are repeated until the efficiency of the electromagnetic radiation reception of the power receiving coil fulfils the pre-set criteria. In case the pre-set criteria is a predetermined threshold, the repetition occurs until the efficiency is equal or above the predetermined threshold.

[0090] As previously mentioned, the vehicle 1 and the wireless charging system 200 can be described in relation to a geometric system with a horizontal plane through which the vertical direction perpendicularly runs. In other words, the vertical direction is a normal to the horizontal plane. For example, the vehicle may be described as extending in a longitudinal direction, from the back of the vehicle to the front of the vehicle, wherein such longitudinal direction extends in the horizontal plane.

[0091] In a fifth step S5, which may be carried out subsequent, or prior, to e.g. the third step S3, the power receiving coil is repositioned relative the power emitting coil in the horizontal plane in response to determining that the efficiency of the electromagnetic radiation reception of the power receiving coil does not fulfil the pre-set criteria. The part of determining that the efficiency of the electromagnetic radiation reception of the power receiving coil does not fulfil the pre-set criteria may e.g. be carried out during the second step S2, or an additional step corresponding to the second step S2 but carried out just prior to the fifth step S5. According to at least one example embodiment, the second step S2 is repeated just prior to performing the fifth step S5.

[0092] As stated previously for the third step S3 and the vertical movement, the movement in the horizontal plane may be carried out by the power receiving coil and/or the power emitting coil.

[0093] In a sixth step S6, the fifth step S5 and the second step S2 (or said step corresponding to the second step S2 carried out just prior to the fifth step S5) are repeated until the efficiency of the electromagnetic radiation reception of the power receiving coil fulfils the pre-set criteria. The sixth step S6 may also include the third step S3 in the repetition. Thus, in such embodiments, the second step S2, the third step S3 and the fifth step S5 are carried out and repeated until the efficiency of the electromagnetic radiation reception of the power receiving coil fulfils the pre-set criteria.

[0094] In a seventh step S7, the power receiving coil is fixed in its position relative the power emitting coil in response to determining that the efficiency of the electromagnetic radiation reception fulfils the pre-set criteria.

[0095] 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, and e.g. the third step S3 and the fifth step S6 may swop places, as well as the fourth step S4 and the sixth step S6. Moreover, the control unit 3 of FIG. 1 may be configured to carry out one or several of the steps S1-S7.

[0096] FIG. 2 and FIG. 3 illustrate schematic views of the wireless charging system 200, 200′. In FIG. 2, the first example embodiment of the re-positioning arrangement 130 of FIG. 1 is shown. That is, in which the re-positioning arrangement 130 comprises, or is integrated into, the attaching device 9, and thus is attached to the undercarriage 5 of the vehicle 1. The far left of FIG. 2 illustrates a position in which the power receiving coil 122 is distanced from the power emitting coil 222 by a first vertical distance d1. This may e.g. be the case during step S1 mentioned with reference to FIG. 4, or as a result of a subsequent 30 step of positioning the vehicle 1 at the charging spot 50, or during a step of determining whether or not the power receiving coil 122 is within an electromagnetic radiation reception distance from the power emitting coil 222. In the middle of FIG. 2, a position in which the power receiving coil 122 is distanced from the power emitting coil 122 by a second vertical distance d2 is shown. Here, the second vertical distance d2 is smaller than the first vertical distance d1, as the re-positioning arrangement 130 has vertically moved the power receiving coil 122 towards the power emitting coil 222, and away from the undercarriage 5 of the vehicle 1 (e.g. by being instructed to do so by the control unit 3). Such smaller distance d2 may e.g. provide a more beneficial vertical distance between 5 the power receiving coil 122 and the power emitting coil 222 with regards to efficiency of the electromagnetic radiation reception of the power receiving coil 122. In the far right of FIG. 2, a position in which the power receiving coil 122 is distanced from the power emitting coil 122 by a second vertical distance d2 being larger than the first vertical distance d1, is shown. Here, the re-positioning arrangement 130 has vertically moved the 10 power receiving coil 122 away from the power emitting coil 222, and towards, and possibly into, the undercarriage 5 of the vehicle 1. Such larger distance d2 may alternatively provide a more beneficial vertical distance between the power receiving coil 122 and the power emitting coil 222 with regards to efficiency of the electromagnetic radiation reception of the power receiving coil 122. The re-positioning arrangement 130 may e.g. comprise an adjustable spring or otherwise extendable/contractible arrangement configured to move the power receiving coil 122 relative the undercarriage 5 of the vehicle 1.

[0097] In FIG. 3, an alternative embodiment of the wireless charging system 200′ is shown. Here, the re-positioning arrangement 230 is arranged on the power emitting coil-side, and is arranged and configured to at least vertically move the power emitting coil 222. In more detail, in middle of FIG. 3, a position in which the power receiving coil 122 is distanced from the power emitting coil 222 by a first vertical distance dl is shown. Correspondingly to FIG. 2, this may e.g. be the case during step S1 mentioned with reference to FIG. 4, or as a result of a subsequent step of positioning the vehicle 1 at the 25 charging spot 50, or during a step of determining whether or not the power receiving coil 122 is within an electromagnetic radiation reception distance from the power emitting coil 222. In the middle of FIG. 2, a position in which the power receiving coil 122 is distanced from the power emitting coil 122 by a second vertical distance d2 is shown. Here, the second vertical distance d2 is smaller than the first vertical distance d1, as the re-positioning arrangement 230 has vertically moved the power emitting coil 222 towards the power receiving coil 122, and away from the ground/foundation in which the power emitting coil 222 is linked to. In the far right of FIG. 3, a position in which the power receiving coil 122 is distanced from the power emitting coil 122 by a second vertical distance d2 being larger than the first vertical distance d1, is shown. Here, the re-positioning arrangement 230 has vertically moved the power emitting coil 222 away from the power receiving coil 122, and towards, and possibly into, ground/foundation. Such smaller, or larger distance d2, may provide a more beneficial vertical distance between the power receiving coil 122 and the power emitting coil 222 with regards to efficiency of the electromagnetic radiation reception of the power receiving coil 122. The re-positioning arrangement 230 may e.g. comprise an adjustable spring or otherwise extendable/contractible arrangement configured to move the power emitting coil 222 relative the ground/foundation. For example, the power emitting coil 222 may be attached to an movable arm.

[0098] It should be noted that the re-positioning arrangement 130, 230 may furthermore be arranged and configured to move the power receiving coil 122 and/or the power emitting coil 222 in the horizontal plane as described with reference to FIG. 4.

[0099] The alternative embodiments which have been disclosed above may be combined in any way which is found advantageous, unless anything else is explicitly stated, as long as the features of the main claims are fulfilled. For example, the two re-positioning arrangements 130, 230 may be combined so as that both the power receiving coil 122 and the power emitting coil 222 can move independently of each other. Moreover, the charging system 200, 200′ of FIG. 2 and FIG. 3, respectively, may be used together with the vehicle 1 of FIG. 1, and as already mentioned, the control unit 3 may be programmed to carry out the method, and the steps S1-S7, as described with reference to FIG. 4.

[0100] 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.

[0101] 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.