Inductive power transfer apparatus

Abstract

One example discloses an inductive power transfer apparatus comprising: a power controller configured to be coupled to a set of primary inductive coils; wherein the power controller is configured to supply power to a first subset of the primary coils; wherein the first subset of the primary coils is configured to inductively deliver power to a set of secondary inductive coils; wherein the power controller is configured to supply the power to a second subset of the primary coils in response to a threshold movement of the secondary inductive coils relative to the primary inductive coils; and wherein the power controller is configured to determine the movement based on: the power supplied to the first subset of the primary coils, and a ratio of power supplied to one of the first subset of the primary coils compared to power supplied to all of the first subset of the coils.

Description

Technical Field

[0001] This specification relates to systems, methods, equipment, apparatus, articles of manufacture, and instructions for use in inductive power delivery devices. Background Technology

[0002] While wireless charging provides a wireless solution for powering and / or recharging devices, it can be highly inefficient if the device being charged is not properly positioned above the wireless inductive charging pad or moves during inductive charging. When the device moves for various reasons, the primary transmission coil in the charging pad and the secondary receiving coil in the device may become misaligned, and / or charging may be interrupted. As a result, power delivery efficiency is reduced and the power consumption of the charging device increases. Summary of the Invention

[0003] According to an example embodiment, an inductive power transfer device includes: a power controller configured to be coupled to a set of primary induction coils; wherein the power controller is configured to supply power to a first subset of the primary coils; wherein the first subset of the primary coils is configured to inductively deliver power to a set of secondary induction coils; wherein the power controller is configured to supply the power to a second subset of the primary coils in response to a threshold movement of the secondary induction coils relative to the primary induction coils; and wherein the power controller is configured to determine the movement based on: the power supplied to the first subset of the primary coils, and the ratio of the power supplied to one primary coil in the first subset of the primary coils to the power supplied to all primary coils in the first subset of the primary coils.

[0004] In another example embodiment, the power controller is configured to determine the distance the secondary coil moves relative to the first subset of the primary coil based on the total power supplied to the first subset of the primary coil.

[0005] In another example embodiment, the power controller is configured to make an increase in the total power supplied to a first subset of the primary coil equivalent to a movement of the secondary coil closer to the first subset of the primary coil; and the power controller is configured to make a decrease in the total power supplied to the first subset of the primary coil equivalent to a movement of the secondary coil away from the first subset of the primary coil.

[0006] In another example embodiment, the power controller is configured to supply power to a first subset of the primary coil when the distance from the secondary coil to the first subset of the primary coil is less than a threshold distance; and the power controller is configured to supply power to a second subset of the primary coil when the distance from the secondary coil to the first subset of the primary coil is greater than the threshold distance.

[0007] In another example embodiment, the power controller is configured to determine the rotation of the secondary coil around the first subset of the primary coils based on a ratio of the power supplied to one primary coil in the first subset of the primary coils to the power supplied to all primary coils in the first subset of the primary coils.

[0008] In another example embodiment, the power controller is configured to supply power to a first subset of the primary coils when the rotation from the secondary coil to the first subset of the primary coils is less than a threshold rotation; and the power controller is configured to supply power to a second subset of the primary coils when the rotation from the secondary coil to the first subset of the primary coils is greater than the threshold rotation.

[0009] In another example embodiment, the power controller is configured to detect the movement based additionally on the self-inductance of the secondary coil.

[0010] In another example embodiment, the power controller is configured to determine the distance between the primary coil and the secondary coil based on the self-inductance of the secondary coil.

[0011] In another example embodiment, the primary coil is coupled to a ferrite sheet.

[0012] In another example embodiment, the power supplied to a subset of the primary coil is constant.

[0013] In another example embodiment, the power supplied to a first subset or a second subset of the primary coils is the same amount.

[0014] In another example embodiment, if the power controller is configured to supply power to a first subset of the primary coils, then the power controller is configured not to supply power to any of the primary coils that are not part of the first subset of the primary coils.

[0015] In another example embodiment, the power controller is coupled to the set of primary coils via a power distribution matrix.

[0016] In another example embodiment, the first and second subsets of the primary coils include at least three primary coils.

[0017] In another example embodiment, the primary coil is embedded in a holding surface; and the secondary coil is embedded in a moving device configured to be placed on the holding surface.

[0018] In another example embodiment, the primary coil is embedded in a wireless inductive charging pad.

[0019] In another example embodiment, if the power controller is configured to supply power to a first subset of the primary coils, the power controller is configured not to supply power to any other induction coils in the inductive charging plate that are not part of the first subset of the primary coils.

[0020] In another example embodiment, each coil in the set of primary transmission coils is substantially the same size; and the set of primary transmission coils is symmetrically distributed throughout the inductive charging plate.

[0021] In another example embodiment, the power controller is configured to supply short power bursts to each subset of the primary coils; and the power controller is configured to determine the location of the secondary induction coils based on: the total power supplied to each of the subsets of the primary coils, and the ratio of the power supplied to one primary coil in each of the subsets to the power supplied to all primary coils in each of the subsets.

[0022] According to an example embodiment, a method for enabling operation of an inductive power delivery device, wherein the device includes a power controller configured to be coupled to a set of primary induction coils, and wherein the primary coils are configured to inductively deliver power to a set of secondary induction coils, the method comprising: allocating a set of instructions stored on a non-transitory, tangible computer-readable storage medium; wherein the instructions include: configuring the power controller to supply power to a first subset of the primary coils; configuring the power controller to supply the power to a second subset of the primary coils in response to a threshold movement of the secondary induction coils relative to the primary induction coils; and configuring the power controller to determine the movement based on: the power supplied to the first subset of the primary coils, and a ratio of the power supplied to one primary coil in the first subset of the primary coils to the power supplied to all primary coils in the first subset of the primary coils.

[0023] The foregoing discussion is not intended to represent every exemplary embodiment or every implementation within the scope of the present or future claims. Various exemplary embodiments are further illustrated in the accompanying drawings and the following detailed description.

[0024] A more comprehensive understanding of the various exemplary embodiments can be obtained by considering the following detailed description taken in conjunction with the accompanying drawings. Attached Figure Description

[0025] Figure 1A This is an example and first view of an inductive power transmission device.

[0026] Figure 1B This is a second view of the inductive power transmission device.

[0027] Figure 1C This is a view of the inductive power receiving device.

[0028] Figure 2A This is the first example of an inductive power receiving device moving relative to an inductive power transmitting device.

[0029] Figure 2B This is a second example of an inductive power receiving device moving relative to an inductive power transmitting device.

[0030] Figure 2C This is the third example of an inductive power receiving device moving relative to an inductive power transmitting device.

[0031] Figure 3 This is an example power controller within an inductive power transmission device.

[0032] Figure 4 This is an example curve of the self-inductance of the secondary receiving coil in an inductive power receiving device.

[0033] Figure 5A This is an example graph showing the distance (e.g., radius) that the inductive power receiving device moves relative to the inductive power transmitting device based on the total power supplied to a set of primary transmission coils in the inductive power transmitting device.

[0034] Figure 5B This is an example graph showing how the total power supplied to a set of primary transmission coils in an inductive power transmission device varies with the angle of the inductive power receiving device relative to the inductive power transmission device.

[0035] Figure 6A , 6B Figures 6C, 6D, 6E, and 6F are example graphs showing how the power balance ratio changes as the angle of the inductive power receiving device relative to the inductive power transmitting device changes.

[0036] Figure 7This includes an example idealized circuit for an inductive power transmission device and an inductive power receiving device.

[0037] While this disclosure allows for various modifications and alternatives, details have been shown in the drawings by way of example and will be described in detail. However, it should be understood that other embodiments besides the specific embodiments described are also possible. All modifications, equivalents, and alternative embodiments falling within the spirit and scope of the appended claims are also covered. Detailed Implementation

[0038] The present invention relates to an example apparatus for monitoring, during operation, the movement between a set of primary power transmission coils in a charging device and a set of secondary power receiving coils in a device to be charged, which are part of a multi-coil wireless power system.

[0039] The device continuously monitors the location of the set of secondary power receiving coils and reroutes power between a first subset and a second subset of the primary coils to continue transmitting power to the set of secondary power receiving coils. In some example multi-coil wireless power systems, this is called receiver location estimation (RPE).

[0040] To track the movement of the set of secondary power receiving coils, the device monitors the properties of a first subset of the primary coils currently delivering power, and switches power to a second subset of the primary coils when these properties exceed one or more predetermined thresholds.

[0041] The monitored properties include: changes in the inductance of the secondary coil to determine the vertical z-axis (Z) gap between the primary and secondary coils; changes in the total power supplied to a first subset of the primary coils to determine the distance (i.e., radius) the primary and secondary coils move relative to each other; and changes in the ratio of the power supplied to one primary coil in the first subset of the primary coils to the power supplied to all primary coils to determine the angle of this movement.

[0042] By realigning the primary coil, which actively supplies power, with the secondary coil, the device can seamlessly (i.e., without power interruption) maintain efficient and ideal power delivery from the primary transmit coil to the secondary receive coil.

[0043] In some example embodiments, the primary coil is embedded in a holding device (e.g., an inductive charging pad), and the secondary coil is embedded in a mobile device (e.g., an earphone, a smartphone, etc.) having a battery to be wirelessly / inductively charged.

[0044] The device examples discussed below provide greater precision in determining when to switch between the first and second sets of primary coils, thereby resulting in higher power delivery efficiency by reducing misalignment between the power delivery and power receiving coils. These example devices also avoid supplying power to the primary coils that cannot effectively deliver induced power to the secondary receiving coils.

[0045] Because not all primary coils of the charging device are activated, EMI emissions are also lower.

[0046] Figure 1A This is an example and a first view of an inductive power transfer device 102. Example 100 includes an inductive power transfer device 102 coupled to a power source (not shown). The inductive power transfer device 102 includes a power controller 104 (e.g., a voltage and / or current controller), a power distribution matrix 106 (simplified), a first set of primary coils 108 including six independently powered coils, a second set of primary coils 110 including six independently powered coils, and a third set of primary coils 112 including three independently powered coils.

[0047] Figure 1B This is a second view of the inductive power transfer device 102. The second view shows the inductive power transfer device 102 from one side and includes: a top layer 114 comprising a first set of primary coils 108, an intermediate layer 116 comprising a second set of primary coils 110, a bottom layer 118 comprising a third set of primary coils 112, a ferrite sheet (not shown), and a retaining surface (not shown). The primary coils 108, 110, and 112 are embedded in the retaining surface, which can accommodate various devices to be charged (e.g., earphones, smartphones, etc.).

[0048] Figure 1C This is a view of an inductive power receiving device 120. The inductive power receiving device 120 is configured to be coupled to a power receiving device (not shown), such as a battery. The inductive power receiving device 120 includes a power receiving controller 122, a power receiving matrix 124 (simplified), and secondary coils 126. In other example embodiments, the inductive power receiving device 120 includes a plurality of secondary receiving coils.

[0049] In some example embodiments, the primary coils 108, 110, and 112 have a diameter of 45 mm, and the secondary coil 126 has a diameter of 70 mm.

[0050] Figure 2AThis is a first example of the inductive power receiving device 120 moving relative to the inductive power transmitting device 102. In this first example 200, the power controller 104 has activated the active primary coils 202, 204, and 206 (i.e., supplying power to the active primary coils 202, 204, and 206). The active primary coil 202 comes from the first group of primary coils 108, the active primary coil 204 comes from the second group of primary coils 110, and the active primary coil 206 comes from the third group of primary coils 112. The power controller 104 has deactivated the passive coil 208 from each of the groups of primary coils 108, 110, and 112 (i.e., preventing power from being supplied to the passive coil 208).

[0051] In this example 200, the center point 210 of the three active primary coils 202, 204, 206 in the inductive power receiving device 120 overlaps with the center point 212 of the secondary coil 126 at time t0. However, due to the direction of movement 214 of the secondary coil 126 relative to the active primary coils 202, 204, 206, these two center points 210, 212 will not overlap again at time t1.

[0052] Figure 2B This is a second example 216 of the inductive power receiving device 120 moving relative to the inductive power transmitting device 102. Figure 2C This is a third example 218 (i.e., a side view) of the movement of the inductive power receiving device 120 relative to the inductive power transmitting device 102.

[0053] In these examples 216, 218, the active primary coils 202, 204, 206 and secondary coil 126 are shown separated by a z-axis gap (Z-gap) 220 (e.g., the distance between the primary and secondary coil planes). The center points 210, 212 overlap at time t0, but after the direction of movement 214, at time t1, the center points 210, 212 will be offset by a radius (R) 222 (e.g., the distance moved). An angle (θ) 224 relative to a predefined xy-axis is also shown after movement 214.

[0054] Figure 3 Example 300 is a power controller 104 within the inductive power transmission device 102. The power controller 104 includes a Z-gap estimator 302, a radius estimator 304, and an angle estimator 306 that jointly determine the Z-gap 220, radius 222, and angle 224 in response to movement 214. Then, an x, y, z position estimator 308 uses the Z-gap 220, radius 222, and angle 224 information to determine the position of the secondary coil 126 of the inductive power receiving device 120 relative to the active primary coils 202, 204, 206 on the holding surface of the inductive power transmission device 102.

[0055] To maintain power delivery efficiency, the power controller 104 switches from a first subset of the active primary coils to a second subset of the primary coils in response to various threshold changes in the Z-gap 220, radius / distance 222, and angle 224. The overall efficiency of the inductive power delivery can be calculated as equal to the output power of the receiving device 120 divided by the input power of the transmitting device 102.

[0056] In some example embodiments, a threshold can be set for switching to the next set of transmission coils if the radius / distance 222 of movement (i.e., the distance change from t0 to t1) is at least 1 / 3 of the diameter of any one of the symmetrical set of active primary transmission coils.

[0057] In some example embodiments, if the angle 224 of the receiving device 120 moves more than a threshold of 60 degrees, the power controller 104 uses the power distribution matrix 106 to switch the supplied power to the next set of primary coils 108, 110, 112.

[0058] In some example embodiments, if the Z-gap 220 exceeds a predetermined distance and / or range, the power controller 104 deactivates all primary coils 108, 110, 112 assuming the power receiving device 120 is no longer on the holding surface. This distance and / or range can be 5 to 10 mm below and above the primary coils 108, 110, 112.

[0059] The threshold distance, angle, and Z-gap 220 used to activate and deactivate the power transmission coil can be stored in a lookup table or calculated using a predetermined equation.

[0060] Z-gap 220 is determined:

[0061] The power controller 104 determines the Z-gap 220 distance based on the self-inductance of the secondary coil 126. In some example embodiments, a slotted quality factor measurement is used to calculate the self-inductance. Other self-inductance calculation algorithms will be well known to those skilled in the art. In some example embodiments, once the self-inductance is known, the Z-gap 220 is retrieved from a lookup table based on previous experimental measurements.

[0062] Figure 4 This is an example 400 experimental curve of the self-inductance of the secondary receiving coil in an inductive power receiving device, where the 13.0 µH self-inductance is equal to the 5 mm Z gap 220.

[0063] To improve the measurement of the self-inductance of the secondary coil 126, the transmission device 102 includes a ferrite sheet, which in some example embodiments is located below the bottom layer 118. The self-inductance of the secondary receiving coil increases as the secondary coil 126 moves closer to the ferrite sheet. If the ferrite sheet is large enough, the self-inductance of the secondary coil 126 does not depend on the xy coordinates of the secondary coil 126 relative to the primary coils 108, 110, 112.

[0064] It should be noted that, depending on the topology (i.e., physical layout) of the receiving device 120, the Z-gap 220 may vary as the receiving device 120 moves within the holding surface, or when a new receiving device 120 (e.g., a smartwatch, laptop computer, earphones, etc.) is placed on the holding surface.

[0065] Movement radius / distance 222 determined:

[0066] The total power routed to the group of active primary coils 202, 204, 206 varies with both the Z-gap 220 and the radius / distance 222. However, for a given Z-gap 220, the total power remains substantially constant with respect to a given radius / distance 222, independent of the angle 224 of the secondary coil 126 relative to the active primary coils 202, 204, 206. Therefore, the radius / distance 222 can be determined based on the Z-gap 220 and the total RMS current routed to the group of active primary coils 202, 204, 206.

[0067] Figure 5A This is an example 500 graph showing the distance (e.g., radius) 222 that the inductive power receiving device 120 moves relative to the inductive power transmitting device 102 based on the total power supplied to the group of active primary coils 202, 204, 206 in the inductive power transmitting device 102. For example: if z = 5 mm and the total active coil current = 8 A, then Figure 5A The radius / distance is shown as 222 = 10 mm.

[0068] The following equation defines the total RMS current, where "n" is the number of active primary coils 202, 204, and 206:

[0069]

[0070] In some example embodiments, based on various Z-gap 220 and, for example Figure 5A The total route RMS current shown is based on previous experimental measurements, with radius / distance 222 retrieved from a lookup table. In other example embodiments, a predetermined equation can be used to calculate radius / distance 222.

[0071] While ideally the total RMS current remains constant across all rotation angles, in some practical example embodiments, the constant total RMS current across all rotation angles is due to manufacturing differences in the active primary coils 202, 204, 206 and the holding surface.

[0072] Figure 5B This is an example 502 graph showing how the total power supplied to the group of active primary coils 202, 204, and 206 in the inductive power transmission device 102 changes with the angle 224 of the inductive power receiving device 120 relative to the inductive power transmission device 102. Figure 5B As shown, the total RMS current fluctuates when the angle 224 changes. This fluctuation can be compensated for in a lookup table.

[0073] Fluctuations can also be reduced or eliminated through coil designs in which the coil height (side view) is much smaller than the z-gap, and / or through coil designs in which the inductance is different in each layer. For example, in some exemplary embodiments, the top coil may have 9 µH, the middle coil may have 8 µH, and the bottom coil may have 7 µH, which will produce the same current distribution in each layer of coils.

[0074] Figure 5B The experimental data in the paper were used for a 10 mm Z-gap 220.

[0075] Angle 224 is determined:

[0076] For a given angle of 224, the power controller 104 calculates the power balance ratio of each of the active primary coils 202, 204, and 206. The power balance ratio is defined according to the following equation:

[0077]

[0078] Where: Pk is the power output of a single active coil; and the sum of Pm is the total power output of all active primary coils 202, 204, and 206.

[0079] Compared to the total power output of all active primary coils 202, 204, and 206, the power output contribution of a single active primary coil varies with angle 224. Geometrically, this variation in power contribution is related to the center point 212 of the secondary coil, which moves around the center point 210 of the active primary coil (see...). Figure 2A and 2B ).

[0080] Figure 6A , 6BFigures 600, 602, 604, 606, 608, and 610 are examples of graphs 600, 602, 604, 606, 608, and 610 showing how the power balance ratio varies as the inductive power receiving device 120 changes angle 224 relative to the inductive power transmitting device 102 (i.e., moves about the inductive power transmitting device 102). As these figures show, for a given radius 222 and Z-gap 220, the Pk_ ratio has a sinusoidal characteristic.

[0081] The exact shape of the power balance ratio variation angle 224 depends on the number and topology of the active primary coils 202, 204, and 206.

[0082] Therefore, the shift angle 224 of the secondary coil 126 from time t0 to t1 can be determined by the magnitude (A) of the power balance ratio of at least two active primary coils 202, 204, 206 (see... Figure 6D The relationship between angle 224 and amplitude can also be derived from lookup tables and / or predetermined equations.

[0083] It should be noted that in the example embodiment shown, such as where the Z-gap = 5 mm Figure 6A And where the Z-gap = 10 mm Figure 6B As shown, the power output contribution of a single active coil does not change with the Z-gap 220, but as in the case of a coil with a radius of 5 mm... Figure 6C And of which the radius = 15 mm Figure 6D As shown, the power output contribution varies with radius / distance 222.

[0084] Figure 6E An alternative graph is shown in this particular example embodiment to show the amplitude (A) of the power balance ratio amplitude against the radius. Therefore, given the known Z-gap 220, radius 222, and power balance ratio amplitude, angle 224 can be determined, and all the information for calculating the x, y, z position of the power receiving device 120 can be determined.

[0085] Figure 6F A specific example is shown where the Z-gap = 5 mm, the radius / distance 222 = 10 mm, and the power to each of the primary coils is P_coil 202 = 16 W, P_coil 204 = 42 W, and P_coil 206 = 42 W, with corresponding power balance ratios of P_1 = 0.42; P_2 = 0.42; P_3 = 0.16, and a power balance ratio amplitude (A) = 0.31. The angle 224 corresponding to these values ​​is approximately 95 degrees.

[0086] Therefore, by monitoring the self-inductance of the secondary coil 126, the total RMS current transmitted to each subset of the primary coils 108, 110, 112, and the ratio of the power transmitted to each active coil in the primary coils 108, 110, 112 to the power transmitted to all active coils in the primary coils 108, 110, 112, the power controller 104 can determine the position of the receiving device 120 relative to the transmitting device 102 from time t0 to time t1.

[0087] In some example embodiments, where the Z-gap 220 is substantially known, a separate Z-gap 220 determination as described above is not required to determine the radius / distance 222 and angle 224. Furthermore, in some example embodiments, the inductance, current, and power determinations described above are independent of the output power of the secondary receiver coil 126.

[0088] Since the power controller 104 monitors the movement of the secondary coil 126 by monitoring the current and power sent to each of the active primary coils and switches the current to the primary coils 108, 110, 112 to maintain a constant input power to the transmitting device 102, the power delivery to the receiving device 120 is not interrupted (e.g., coil switching during operation).

[0089] Furthermore, since the Z-gap 220, radius / distance 222, and angle 224 can be determined while the inductive power transmission device 102 is operating, there is no need to create a "time slot" that interrupts the wireless inductive charging of the secondary receiving coil.

[0090] In some example embodiments, the Z-gap 220, radius / distance 222, and angle 224 can be determined even before wireless inductive charging of the secondary receiving coil begins. In such an example embodiment, short power bursts on various subsets of the primary coil are used to perform an initial search for the secondary coil 126 located somewhere on the holding surface. These short power bursts can also form part of the standby mode of the inductive power transfer device 102 when the secondary coil 126 is not present. The short power bursts allow the radius / distance 222 and angle 224 to be determined using the same principles discussed above.

[0091] In other example embodiments, when multiple mobile devices are located within the holding surface, short power surges to various subsets of the primary coil are used to detect additional secondary receiving coils.

[0092] Figure 7Example 700 includes idealized circuitry for an inductive power transfer device 702 and an inductive power receiving device 704. The inductive power transfer device 702 includes a power input port 706 from a power source (not shown) and active primary coils 708, 710, 712. The inductive power receiving device 704 includes a secondary receiving coil 714 and a power output port 716 to a power receiving device (not shown), such as a battery. The active primary coils 708, 710, 712 deliver power to the secondary receiving coil 714 based on coupling coefficients 718, 720, 722.

[0093] Power controller 104 monitors three powers (i.e., TX0, TX1, TX2) routed to each of the active primary coils 708, 710, 712, which can operate at frequencies close to the resonant frequency. The three powers depend on coupling coefficients 718, 720, 722. In response to the movement of receiving device 704 relative to transmitting device 702 from time t0 to time t1, coupling coefficients 718, 720, 722 change with Z-gap 220, radius 222, and angle 224.

[0094] When comparing two positions of two different primary coil groups, in the absence of power rerouting by power controller 104, the output voltage of receiver 704 at port 716 will vary with the position of secondary receiver coil 714 relative to active primary coils 708, 710, 712. For small movements within a single primary coil group, the voltage will not change significantly.

[0095] However, by rerouting power from port 706 to the next set of active primary coils (not shown) as the receiving device 704 moves, the output voltage of the receiving device 704 remains substantially constant, just like the input power of the transmitting device 702.

[0096] In some example embodiments, the output power of the transmission device 702 is adjusted by the amplitude of a 50% duty cycle square wave signal from the power input port 706. The power can also be adjusted by the phase (duty cycle).

[0097] Various example embodiments of the inductive power transmission device 102 implement receiver location estimation (RPE) for a multi-coil inductive wireless power transmission device, such as the inductive power receiving device 120.

[0098] These applications include inductive power receiving devices, such as laptops, tablets, smartphones, input devices (e.g., electronic pens, mice, etc.), earphones, car battery charging (e.g., parking lots, roads, etc.), and devices that require wireless power delivery and a large degree of freedom of movement without power interruption (e.g., automated warehouse carts, industrial equipment, robots, etc.).

[0099] Unless a specific order is explicitly stated, the various instructions and / or operational steps discussed in the above figures can be performed in any order. Furthermore, those skilled in the art will recognize that while some example sets of instructions / steps have been discussed, the material in this specification can be combined in various ways to produce other examples, and should be understood within the context provided by this specific embodiment.

[0100] In some example embodiments, these instructions / steps are implemented as functional and software instructions. In other embodiments, the instructions may be implemented using logic gates, dedicated chips, firmware, and other hardware forms.

[0101] When instructions are implemented as a set of executable instructions in a non-transitory computer-readable or computer-usable medium, these instructions are implemented on a computer or machine programmed with and controlled by the executable instructions. The instructions are loaded to execute on a processor (e.g., one or more CPUs). The processor includes a microprocessor, microcontroller, processor module or subsystem (including one or more microprocessors or microcontrollers), or other control or computing device. A processor may refer to a single component or multiple components. The one or more computer-readable or computer-usable storage media are considered part of an article (or article of manufacture). An article or article of manufacture may refer to any manufactured single component or multiple components. One or more non-transitory machine or computer-usable media as defined herein do not include signals, but such one or more media may be capable of receiving and processing information from signals and / or other transient media.

[0102] It will be readily understood that the components of the embodiments generally described herein and illustrated in the accompanying drawings can be arranged and designed in a wide variety of different configurations. Therefore, the specific implementations of the various embodiments illustrated in the figures are not intended to limit the scope of this disclosure, but merely to illustrate various embodiments. Although various aspects of the embodiments are presented in the drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0103] The invention may be implemented in other specific forms without departing from the spirit or essential characteristics thereof. The described embodiments are to be regarded in all respects as illustrative rather than restrictive. Therefore, the scope of the invention is indicated by the appended claims rather than by the specific embodiments described therein. All changes that appear within the equivalent meaning and scope of the claims are covered by the scope of the claims.

[0104] References to features, advantages, or similar language throughout this specification do not imply that all features and advantages achievable through the invention should be included in or in any single embodiment of the invention. In fact, language relating to features and advantages should be understood to mean that a particular feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the invention. Therefore, discussions of features and advantages throughout this specification, as well as similar language, may (but are not necessarily) refer to the same embodiment.

[0105] Furthermore, the features, advantages, and characteristics described in this invention can be combined in one or more embodiments in any suitable manner. Those skilled in the art will recognize that, in view of the description herein, this invention can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages that may not be present in all embodiments of the invention can be identified in certain embodiments.

[0106] Throughout this specification, references to "an embodiment," "embodiment," or similar language mean that a particular feature, structure, or characteristic described in connection with the indicated embodiment is included in at least one embodiment of the invention. Therefore, the phrases "in one embodiment," "in an embodiment," and similar language throughout this specification may (but not necessarily) all refer to the same embodiment.

Claims

1. An inductive power transfer device, characterized by, include: A power controller configured to be coupled to a set of primary coils; The power controller is configured to supply power to a first subset of the primary coil; The first subset of the primary coils is configured to inductively deliver power to a set of secondary coils; The power controller is configured to supply power to a second subset of the primary coil in response to a threshold shift of the secondary coil relative to the primary coil; and The power controller is configured to determine the movement based on the following: the power supplied to a first subset of the primary coils, and the ratio of the power supplied to one primary coil in the first subset of the primary coils to the power supplied to all primary coils in the first subset of the primary coils; The power controller is configured to supply short power bursts to each subset of the primary coils; and the power controller is configured to determine the location of the secondary coils based on the total power supplied to each of the subsets of the primary coils, and the ratio of the power supplied to one primary coil in each of the subsets to the power supplied to all primary coils in each of the subsets.

2. The inductive power transmission device according to claim 1: characterized in that The power controller is configured to determine the distance the secondary coil moves relative to the first subset of the primary coil based on the total power supplied to the first subset of the primary coil.

3. The inductive power transmission device according to claim 2: characterized in that The power controller is configured such that an increase in the total power supplied to a first subset of the primary coil is equivalent to a movement of the secondary coil closer to the first subset of the primary coil; and The power controller is configured such that a reduction in the total power supplied to a first subset of the primary coil is equivalent to a movement of the secondary coil away from the first subset of the primary coil.

4. The inductive power transmission device according to claim 2: characterized in that The power controller is configured to supply power to the first subset of the primary coils when the distance from the secondary coil to the first subset of the primary coils is less than a threshold distance; and The power controller is configured to supply power to a second subset of the primary coils if the distance from the secondary coil to a first subset of the primary coils is greater than the threshold distance.

5. The inductive power transmission device according to claim 1: characterized in that The power controller is configured to determine the rotation of the secondary coil around the first subset of the primary coils based on a ratio of the power supplied to one primary coil in the first subset of the primary coils to the power supplied to all primary coils in the first subset of the primary coils.

6. The inductive power transmission device according to claim 5: characterized in that The power controller is configured to supply power to the first subset of the primary coils when the rotation from the secondary coil to the first subset of the primary coils is less than a threshold rotation; and The power controller is configured to supply power to a second subset of the primary coils when the rotation of the first subset from the secondary coil to the primary coil is greater than the threshold rotation.

7. The inductive power transmission device according to claim 1: characterized in that The power controller is configured to detect the movement based on the self-inductance of the secondary coil.

8. The inductive power transmission device according to claim 1: characterized in that The power supplied to the subset of the primary coil is constant.

9. The inductive power transmission device according to claim 1: characterized in that If the power controller is configured to supply power to a first subset of the primary coils, then the power controller is configured not to supply power to any of the primary coils that are not part of the first subset of the primary coils.

10. A method for enabling operation of an inductive power transfer apparatus, characterized by, The device includes a power controller configured to be coupled to a set of primary coils, wherein the primary coils are configured to inductively deliver power to a set of secondary coils, and the method includes: Allocate instruction sets stored on non-transitory, tangible, computer-readable storage media; The instructions mentioned therein include: Configure the power controller to supply power to a first subset of the primary coils; The power controller is configured to supply power to a second subset of the primary coil in response to a threshold shift of the secondary coil relative to the primary coil; and The power controller is configured to determine the movement based on the following: the power supplied to a first subset of the primary coils, and the ratio of the power supplied to one primary coil in the first subset of the primary coils to the power supplied to all primary coils in the first subset of the primary coils; The power controller is configured to supply short power bursts to each subset of the primary coils; and the power controller is configured to determine the location of the secondary coils based on the total power supplied to each of the subsets of the primary coils, and the ratio of the power supplied to one primary coil in each of the subsets to the power supplied to all primary coils in each of the subsets.

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