CN114365246A - Data link for resonant inductive wireless charging - Google Patents

Abstract

A full-duplex, low-latency near-field data link controls a resonant inductive wireless power transfer system for recharging a battery. In an electric vehicle embodiment, the assembly is aligned relative to a ground assembly to receive a charging signal. The vehicle assembly includes one or more charging coils and a first full-duplex inductively coupled data communication system in communication with a surface assembly that includes the one or more charging coils and a second full-duplex inductively coupled data communication system. The charging coil of the ground assembly and the vehicle assembly are selectively activated for charging based on a geometric positioning of the vehicle assembly relative to the ground assembly. The ground component and/or the transmitting/receiving system of the vehicle component are adapted to be of the same type, as appropriate, to enable communication of charge management and control data between the ground component and the vehicle component during charging.

Description

Data link for resonant inductive wireless charging

Priority declaration

This application claims benefit of priority from U.S. application serial No. 16/675,618 filed on 6.11.2019 and also claims benefit of priority from U.S. application serial No. 16/570,801 filed on 13.9.2019, both of which are incorporated herein by reference in their entirety.

Technical Field

A full-duplex near-field data link intended for controlling a resonant inductive wireless power transfer system is used for recharging electric vehicles. A coherent transponder configuration enables interference-suppressed synchronous detection and positive suppression of signals originating from nearby and neighboring vehicles.

Background

Inductive power transfer has many important applications across many industries and markets. Resonant inductive wireless power devices can be viewed as a switched mode DC to DC power supply with a large air gap transformer separating and isolating the power supply input and output portions. Since the output current is controlled by adjusting the input side parameter, there must be a method of passing the output parameter to the input side control circuit. Conventional isolated switched mode power supplies use optocouplers or coupling transformers to communicate across the isolation barrier, but these conventional approaches are not useful in the presence of large physical gaps. Acoustic and optical communication across the power transmission gap is possible in principle, but is not sufficient in practice when challenged by mud, road debris, snow ice and standing water. Communication can be made across the power transfer gap by modulating the receive inductor impedance and detecting the voltage and current variations induced on the primary side inductor. However, due to the typically low operating frequencies employed by resonant inductive wireless power transfer devices and the medium to high load Q values of the primary side and secondary side inductors of such resonant inductive wireless power transfer systems, the available data communication bandwidth is severely limited and full duplex communication implementations are difficult.

Therefore, radio frequency based data communication systems are preferred because radio frequency based data communication systems are not affected by the difficulties listed above; however, conventional radio frequency data communication systems are inadequate in several respects. A half-duplex system transmits in only one direction, but rapidly alternates the direction of transmission, creating a data link that acts as a full-duplex link. The transmission data buffering or queuing introduces significant and variable transmission delays, which is particularly undesirable as a cause of control system instability when placed in the control system feedback path.

Conventional superheterodyne receivers typically require fairly good intermediate frequency filters to provide off-channel interference rejection. However, such filters tend to be expensive and do not readily lend themselves to monolithic integration.

Furthermore, conventional radio data links do not inherently distinguish between other nearby data links of the same type. This means that conventional radio-based data links, when used to facilitate addressing wireless charging of electric vehicles, often respond to radio commands issued by charging devices in nearby or adjacent parking spaces, a behavior that greatly complicates explicit vehicle identification and subsequent wireless charging control.

Disclosure of Invention

The systems and methods described herein address the above and other limitations of the prior art by implementing a coherent full-duplex radio frequency data link that relies on near-field inductive coupling as opposed to far-field propagation in conventional systems to limit the effective communication range, that employs synchronous detection to suppress out-of-channel and some co-channel interference without complex frequency domain filtering, and that employs a coherent repeater (transponder) architecture for positive identification of data link transmit-receive device pairs.

In an example embodiment, two apparatuses are provided, one apparatus being associated with a ground-side wireless power transmitting apparatus and the other apparatus being associated with a vehicle-side wireless power receiving apparatus. A crystal controlled reference oscillator located in the ground-side device provides a common basis for coherent generation of all radio frequency signals required for transmission and detection. Since this is a full duplex communication device, there are two independent transmit-receive chains: a forward link from the ground-side device to the vehicle-side device, and a return link from the vehicle-side device to the ground-side device. The vehicle-side loop antenna is generally located below the conductive body bottom of the vehicle and parallel with respect to the ground surface.

The forward link transmission signal is derived from a reference oscillator. Serial data is applied by a modulator to a forward link carrier. Transmission occurs between two electrically small loop antennas with significant mutual inductive coupling that are spaced far less than the wavelength at the forward link operating frequency. On the vehicle side of the forward link, the received signal is detected by a homodyne detector, which extracts the carrier of the signal and uses it as a detection reference in a synchronous detector. The extracted carriers are multiplied in frequency and used as the carrier for the return link, with return link data being applied to the carrier with the second modulator. The return link transmission occurs through near field inductive coupling between two closely spaced electrically small loop antennas as previously described. A synchronization detector on the ground side of the link extracts the return link data using a multiplied version of the original reference oscillator signal as a detection reference. The link modulation in both directions may be amplitude modulation, phase modulation, or a combination of both.

Since the forward link carrier, forward link sensing reference, return link carrier and return link sensing reference are all derived from the same reference oscillator, the coherency of these four critical signals is ensured by design. No complex frequency acquisition and synchronization circuits are required. Furthermore, production tolerances and environmentally induced frequency variations between the reference oscillators ensure that the link signals from devices located in adjacent parking spaces will not be coherent and will therefore not be subject to synchronous detection. Further suppression of link signals originating from devices and vehicles in adjacent parking spaces results from attenuation that occurs when the link transmission wavelength exceeds the separation distance of the vehicle underbody to the ground surface, where the vehicle underbody and ground surface act as two plates of a waveguide that operates below the waveguide propagation cutoff frequency.

According to a first aspect, there is provided a charging system comprising: a first coil assembly comprising a charging coil and a first full-duplex inductively coupled data communication system, the first full-duplex inductively coupled data communication system comprising a first transmit/receive system that transmits a first signal over a first inductive link and receives a second signal over a second inductive link; and a second coil assembly comprising a charging coil and a second full-duplex inductively coupled data communication system, the second full-duplex inductively coupled data communication system comprising a second transmit/receive system, the second transmit/receive system receiving the first signal through the first inductive link and transmitting the second signal through the second inductive link. In an example embodiment, the first and second transmission/reception systems are adapted to be selectable in at least one of hardware, software and firmware configurations adapted to modulate the output signal and to demodulate the input signal. Further, the charging coil of the first coil assembly is configured to be disposed in parallel with the charging coil of the second coil assembly to receive a charging signal during charging and to be selectively enabled to match a geometry of the second coil assembly during charging.

In an example embodiment, the first transmit/receive system includes a processor that processes data from at least one of the first coil assembly and an external system for transmission to the second coil assembly and processes data received from the second coil assembly for delivery to at least one of the first coil assembly and the external system for processing. In an example embodiment, the processor disables the charging signal when the first coil assembly detects a fault event or when a fault event is received from the second coil assembly.

In other example embodiments, the second transmission/reception system includes a processor that processes at least one of commands and data from the second coil assembly and from an external system for transmission to the first coil assembly, and processes data received from the first coil assembly for delivery to the at least one of the external system and the second coil assembly. In an example embodiment, the second coil assembly further comprises a digital interface, and the processor provides measurements related to the first signal, the second signal, and the charging signal to the digital interface. The measurement results include at least one of: signal strength, bit error rate, ratio of energy per bit to spectral noise density, frequency, and amplitude and phase shifts at the first and second antenna structures of the first and second coil assemblies. In an example embodiment, the external system may include an external processor. In such embodiments, the measurements are delivered to an external processor via a digital interface for at least one of alignment detection and closed loop charging system management and control. The external processor may provide the following to the processor for transmission: near real-time voltage and current measurements on the second coil assembly, thermal measurements of the second coil assembly, Z gap changes, a fault alarm of the first coil assembly or the second coil assembly, an alarm regarding an intermediate charge performance event, and additional sensed data related to the second coil assembly.

In other example embodiments, the first and second signals are configured as narrowband or wideband signals depending on the phase of the charging cycle or whether a threshold of signal quality has been crossed.

In other example embodiments, the first signal and the second signal are configured as asynchronous spread spectrum signals. In such embodiments, the first and second transmission/reception systems may each comprise a direct sequence spread spectrum system transmitting a sequence of complementary codes as follows: the complementary code sequences enable the first and second transmit/receive systems to distinguish signals from co-channel interference.

In an example embodiment, the hardware, software and/or firmware is adapted to modulate the output signal using at least two of: amplitude modulation, phase modulation, frequency modulation, Orthogonal Frequency Division Multiplexing (OFDM), and spread spectrum techniques. The spread spectrum technique may include at least one of: direct sequence spread spectrum (CSS), Chirp Spread Spectrum (CSS), binary quadrature keying (BOK), and frequency hopping.

In other example embodiments, the first and second transmission/reception systems each include: a receiver, an analog-to-digital converter, a digital processor, a digital-to-analog converter, and a transmitter, the digital processor processing data from at least one of the first coil assembly and the external system for transmission to the second coil assembly and processing data received from the second coil assembly for delivery to at least one of the first coil assembly and the external system for processing. In an example embodiment, the analog-to-digital converter and the digital-to-analog converter are implemented as discrete integrated circuits, and the digital processor is implemented as a field programmable gate array. Further, the analog-to-digital converter, digital processor, and digital-to-analog converter may be implemented as firmware residing in an Application Specific Integrated Circuit (ASIC). In an example embodiment, the digital processor of each transmit/receive system processes input data for transmission and processes data received from other transmit/receive systems using software structures implemented on the digital processor. The first and second transmit/receive systems may optionally include at least one band pass filter.

According to a second aspect, there is provided a method of charging a vehicle, the method comprising positioning a vehicle assembly relative to a ground assembly for receiving a charging signal, the vehicle assembly comprising one or more charging coils, wherein each charging coil has a first full-duplex inductively coupled data communication system including a first transmit/receive system, the first transmit/receive system receives a first signal through a first inductive link and transmits a second signal through a second inductive link, and the surface assembly includes one or more charging coils, wherein each charging coil has a second full-duplex inductively coupled data communication system including a second transmit/receive system, the second transmit/receive system transmits a first signal through the first inductive link and receives a second signal through the second inductive link. The charging coil of the ground assembly and the vehicle assembly are selectively activated for charging based on a geometric positioning of the vehicle assembly relative to the ground assembly. At least one of the first and second transmission/reception systems is selected to have the same type of hardware, software and/or firmware adapted to modulate the output signal and to demodulate the input signal in the same manner as the other of the first and second transmission/reception systems. During charging, charging management and control data is communicated between the first and second transmit/receive systems over the first and second inductive links.

In an example embodiment, the first and second transmission/reception systems are adapted to modulate the output signal using at least two of: amplitude modulation, phase modulation, frequency modulation, Orthogonal Frequency Division Multiplexing (OFDM), and spread spectrum techniques. The spread spectrum technique may include at least one of: direct sequence spread spectrum (CSS), Chirp Spread Spectrum (CSS), binary quadrature keying (BOK), and frequency hopping.

In other example embodiments, at least one of software updates, diagnostic or telemetry information, and passenger entertainment service data is communicated between the surface component and the vehicle component via the first inductive link and the second inductive link during charging. The charging signal may be disabled when the surface component detects a fault event or receives a fault event from a vehicle component.

In other example embodiments, the first transmit/receive system processes at least one of commands and data from the vehicle components and the external systems for transmission to the surface components, and processes data received from the surface components for delivery to the vehicle components and at least one of the external systems. Measurements related to the first signal, the second signal, and the charging signal may also be provided to a digital interface for processing. The measurement results may include at least one of: signal strength, energy per bit to spectral noise density ratio, frequency, and amplitude and phase shifts at the first and second antenna structures of the vehicle and ground components. The measurements may be delivered to an external processor via a digital interface for at least one of alignment detection and closed loop charging system management and control.

In still other example embodiments, the method includes sending at least one of the following from the vehicle component to the ground component: near real-time voltage and current measurements on the vehicle components, thermal measurements of the vehicle components, Z gap changes due to loading or unloading of a vehicle containing the vehicle components, fault alerts of ground or vehicle components, alerts regarding mid-charge performance events, and additional sensed data related to the vehicle components.

In still further example embodiments, the method comprises: the first and second signals are configured as narrowband or wideband signals depending on the phase of the charging cycle or whether a threshold of signal quality has been crossed.

In yet further example embodiments, the method comprises: the first signal and the second signal are configured as asynchronous spread spectrum signals. Complementary code sequences may be transmitted between the first and second transmit/receive systems, the complementary code sequences enabling the first and second transmit/receive systems to distinguish signals from co-channel interference.

According to a third aspect, there is provided a vehicle charging system comprising a trunked ground assembly comprising at least two independent coils, each coil having a first full duplex inductively coupled data communications system comprising a transmit/receive system that transmits a first signal over a first inductive link and receives a second signal from a vehicle over a second inductive link, the first and second signals being communicated between the trunked ground assembly and the vehicle during vehicle charging. The cluster floor assemblies may include individual floor assemblies mounted in close succession to form a single large floor assembly.

In an example embodiment, the vehicle being charged has two or more vehicle components mounted to allow higher power transfer than can be achieved with a single vehicle component, and the cluster ground component includes a coil configured to match the geometry of the two or more vehicle components.

In further example embodiments, the charged vehicle may be equipped with a cluster vehicle assembly in a geometry that matches the cluster ground assembly. The trunked vehicle assembly may include at least two independent coils, each coil having a second full-duplex inductively coupled data communication system including a transmit/receive system that transmits a second signal over a second inductive link and receives a first signal from the trunked ground assembly over a first inductive link, the first and second signals being communicated between the trunked ground assembly and the trunked vehicle assembly during vehicle charging.

The trunked vehicle assembly and the trunked ground assembly may each include two or more functionally identical assemblies, each functionally identical assembly including a magnetic induction antenna and a common resonant induction coil unit.

Drawings

The foregoing and other advantageous features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, in which:

fig. 1 shows a conceptual representation of an example embodiment of a ground-side transmission device and a vehicle-side transmission device.

Fig. 2 illustrates an example embodiment of a full duplex radio frequency data link.

Fig. 3 shows low harmonic waveforms employed by the example embodiment of fig. 2 to avoid self-interference.

Fig. 4 shows a representation of digital amplitude shift modulation used by the example embodiment of fig. 2.

Fig. 5 illustrates an embodiment of a low harmonic generation circuit that produces the waveforms shown in fig. 3.

Fig. 6 shows a representation of digital amplitude shift modulation used by the embodiment of fig. 2.

Fig. 7 shows an embodiment of a receiver level detection circuit.

Fig. 8 illustrates an embodiment of an apparatus for self-interference cancellation.

Fig. 9 illustrates an embodiment of dynamic charging using the communication methods described herein.

Fig. 10 shows an example of a cluster deployment of transmission devices in an example embodiment.

Figure 11a illustrates signal transmission and components used by an Inductively Coupled Communication System (ICCS) of a Wireless Power Transfer (WPT) system in an example embodiment.

Fig. 11b shows an example of a diversity receiver antenna of an Inductively Coupled Communication System (ICCS) for a Wireless Power Transfer (WPT) system.

Fig. 12a shows functional elements of an ICCS in an example embodiment.

Fig. 12b illustrates an example hardware implementation of an ICCS that includes a vehicle-side assembly and a ground-side assembly.

Figure 13a shows a top view of a parking lot based wireless charging station deployed in a single row geographic arrangement in an example embodiment.

Figure 13b shows a top view of a parking lot based wireless charging station deployed in a dual bank geographic arrangement in an example embodiment.

Fig. 14 shows an example of a highway that can be used for dynamic charging in an example embodiment.

Detailed Description

Example embodiments for charging an electric vehicle will be described with reference to fig. 1-14, but those skilled in the art will appreciate that the teachings provided herein may be used with other non-vehicle resonant magnetic induction wireless power transfer systems. Such embodiments are intended to be within the scope of the present disclosure.

Fig. 1 shows a conceptual representation of an example embodiment, in which two devices are provided: a ground-side device associated with the ground-side wireless power transmitting apparatus, and a vehicle-side device associated with the vehicle-side wireless power receiving apparatus. The data link shown in fig. 1 may be implemented, for example, in a coil alignment error detection apparatus described in U.S. patent No. 10,193,400. As shown in fig. 1, the ground-side apparatus includes: a frequency multiplier 10; a data modulator 20 that receives input data for transmission; and a synchronization detector 30 that receives data from the vehicle-side device on a return link and provides output data. Similarly, the vehicle-side device includes: a frequency multiplier 40; a homodyne detector 50 that receives data from the ground-side device on the forward link; and a modulator 60 which transmits the data on the return link to the ground-side device. The loop antennas 70 and 70 'of the ground-side device wirelessly communicate by induction with the loop antennas 80 and 80' on the vehicle-side device in a conventional manner. A crystal controlled reference oscillator 90 located in the ground-side device provides a common basis for coherent generation of all radio frequency signals required for transmission and detection. Since this is a full duplex communication device, there are two independent transmit-receive chains: a forward link from the ground-side device to the vehicle-side device, and a return link from the vehicle-side device to the ground-side device. The vehicle-side loop antennas 80 and 80 'are generally located below the conductive bottom of the vehicle body and are parallel with respect to the ground-side loop antennas 70 and 70'.

The systems and methods described herein and illustrated in fig. 1 differ from conventional radio data communications as follows:

the communication path is full duplex and bidirectional, with a forward path from the ground-side device to the vehicle-side device, and a second return data path from the vehicle-side device to the ground-side device starting with the transmission of data.

The electronic communication mechanism is near-field magnetic field coupling between the two antennas 70,80 and 70', 80' that is sensitive to impinging magnetic field energy, rather than far-field free-space propagation of conventionally practiced radio frequency data communications.

-the forward path signal carrier providing a basis for generating the secondary path signal by means of frequency multiplication. This means that the secondary path signal is harmonically related to the forward path signal and avoids the technical difficulties of deriving synchronous and coherent reference signals for return path synchronous detection. Furthermore, coherent harmonically correlated forward path signals, return path signals make it possible to simply and unambiguously suppress co-channel and off-channel interference and suppress data link signals originating from other identical devices in adjacent parking spaces.

In the exemplary embodiment shown in fig. 2, the forward path frequency from the reference oscillator 90 is 13.560 MHz. The return path operates at the third harmonic 40.680MHz of the forward path. Both of these frequencies are allocated internationally for non-communications industrial, scientific and medical (ISM) uses. Communication usage is also allowed in ISM channels with reduced regulatory requirements, but interference is accepted from all other ISM channel users. The non-radiating near-field nature of the coherent transponder system described herein and the waveguide below the cut-off structure comprised by the vehicle conducting underbody and ground surface in typical applications make the described system very tolerant to co-channel interference and for this reason very suitable for ISM specified frequencies.

The forward path signal generation begins with a reference quartz crystal oscillator 90 operating at a frequency of 13.560 MHz. The signal is applied to a waveform generation stage comprising a third harmonic cancellation circuit 22 and an amplitude-shift modulator 24 which together comprise the modulator 20 of figure 1. Of course, other types of modulators may be used, such as frequency shift modulators, QPSK modulators, and the like. In an exemplary embodiment, the amplitude shift modulator 24 generates a rectangular waveform as shown in fig. 3, where T is the waveform period and the third harmonic power is approximately zero. A small loop antenna 70 with balanced feed is used as the forward path transmit antenna and a second vehicle-mounted balanced feed small loop antenna 80 is used as the forward path receive antenna. Both antennas 70,80 are much smaller than the wavelength at the operating frequency and for this reason are poor free space radiators. However, when in close physical proximity, the two small loop antennas 70,80 have significant mutual magnetic field coupling, which enables both forward and reverse communication paths without significant free-space propagation.

The Fourier series coefficients of the modified sinusoidal waveform shown in FIG. 3 are given by the following equation, in accordance with "Engineering materials Handbook", third edition, Tuma, Jan J., McGraw-Hill 1987 ISBN 0-07-065443-3:

of the first twenty fourier series coefficients, all but six fourier series coefficients are zero. For the desired n-1 component, the non-zero coefficients are: 5 th and 7 th, suppressed by-14 dB and-16.9 dB; 11 th and 13 th, suppressed by-20.8 dB and-22.3 dB; and 17 th and 19 th, suppressed by-22.9 dB and-25.5 dB. Although mathematically ideal waveforms have infinite third harmonic rejection, practical implementations will have less than infinite harmonic cancellation due to unequal 0-1 and 1-0 logic propagation delays and asymmetry from other small waveforms. Even so, the waveform of FIG. 3 generated by the 3 rd harmonic cancellation circuit 22 with the circuit shown in FIG. 5 has excellent third harmonic rejection (3 rd harmonic energy is near zero), a very desirable feature to avoid self-interference between the third harmonic of the forward transmission path and the detection of the 40.680MHz return path. The remaining residual third harmonic energy can be further suppressed, if desired, using conventional harmonic filtering techniques.

The low third harmonic generation circuit shown in fig. 5 comprises a stepped ring counter consisting of three D flip- flops 102, 104, 106, the three D flip- flops 102, 104, 106 being clocked at six times the required output frequency derived by a PLL frequency multiplier 108 from the 13.560MHz frequency from the reference oscillator 90. A pair of NAND gates 110, 112 decodes the step-loop counter to produce the required rectangular wave that drives the forward link loop antenna 70 by means of two transistors 114, 116 arranged in a symmetrical push-pull configuration. The inductance of the two radio frequency chokes 118, 120 connected to the voltage source 122 in combination with the inductance of the loop antenna 70 and the antenna resonant capacitor 124 shown in fig. 5 constitute a resonant circuit that provides suppression of residual harmonic energy, particularly the third harmonic in the illustrated embodiment.

As shown in fig. 2, in the exemplary embodiment, Amplitude Shift Keying (ASK) modulation is applied to the forward link carrier by amplitude shift modulator 24 by varying the value of the forward link transmit stage supply voltage. A logical one bit is encoded as a full signal amplitude, with the transmit stage operating from a full supply voltage. The logical zero bit is encoded as half the full signal amplitude with the transmit stage operating at a reduced supply voltage. Varying the transmitter stage supply voltage in this manner produces the transmit waveform shown in fig. 4.

On the vehicle side of the forward link, the variable gain control amplifier 52 increases the received signal amplitude from the loop antenna 80. Since the received signal has a non-zero value even for a logical zero, there is always a 13.56MHz carrier present (see fig. 4). A portion of the amplified received signal is applied to a limiting amplifier 54, which limiting amplifier 54 removes received signal amplitude variations introduced by the amplitude data modulation and which occur due to incidental variations in the magnetic field coupling between the two forward path loop antennas 70, 80. The output of the limiting amplifier 54 is a constant amplitude square wave indicating the instantaneous polarity of the received signal. The portion of the variable gain amplifier output not applied to limiting amplifier 54 is applied to one input of a multiplying mixer 56. The output of limiting amplifier 54 drives the other mixer input. Limiting amplifier 54 and mixer 56 include a homodyne detector 50 in which the input signal carrier is extracted and used to synchronously detect the input signal. The propagation delay of limiting amplifier 54 can be ignored or compensated for to achieve the full advantage of coherent detection. The output of the homodyne detector 50 is equivalent to full-wave rectification of the input amplitude modulated signal. Resistor-capacitor low pass filtering removes the double carrier frequency ripple, leaving a dc voltage that varies in amplitude in accordance with the applied serial digital modulation. The carrier ripple filtered post-homodyne detector signal is applied to a level detection circuit 59, the level detection circuit 59 feeding an Automatic Gain Control (AGC) control loop 58, and also extracts the forward path serial data by means of amplitude level detection. An implementation of which will be described in more detail below with reference to fig. 7.

The forward path carrier recovered by the limiting amplifier 54 is applied to a frequency tripler 42 implemented as a pulse generator, the frequency tripler 42 followed by a filter or, equivalently, a phase locked loop after first passing through a crystal filter 44 that disables the frequency doubler operation except in the presence of a sufficiently strong forward link signal to avoid conflicting frequencies. The resulting 40.680MHz carrier is applied to the second amplitude-shifting modulator 62 using the 100% and 50% modulation levels as previously described to encode the serial digital data on the return data path. The return path amplitude shift modulator 62 drives the small resonant loop antenna 80' as previously described, except that elements 102-112 of fig. 5 are not required.

On the ground side of the return link there is an amplifier 32 controlled by an Automatic Gain Control (AGC) circuit 34 and a small resonant loop receive antenna 70'. Synchronous detection of the received return path signal is achieved by generating an 40.680MHz synchronous detection reference signal by means of frequency tripling. Although the frequency error of the synchronous detection reference signal is guaranteed to be zero by the overall design of the apparatus, a zero phase error cannot be guaranteed and obtained by using quadrature channel phase detection and phase-locked loop control of the phase shifter stage. Placing the phase shift stage (phase shifter 12) before the frequency tripler 14 instead of after the frequency tripler 14 means that the total phase shift control range only needs to exceed 120 degrees instead of the full 360 degrees needed by the synchronous detector 30 to ensure phase synchronous detection. To facilitate quadrature reference signal generation at 40.680MHz, the ground-side 13.560MHz signal from crystal oscillator 90 is multiplied by frequency tripler 14, which outputs two square waves offset by 90 °. The frequency tripler 14 is implemented as a 6-fold phase-locked loop frequency multiplier followed by a quadrature by two-frequency (quadrature by two) circuit, shown in fig. 6, comprising D flip- flops 130, 132 to obtain the I and Q synchronous detection reference signals. It will be appreciated that when the Q channel signal output at 17 is equal to 0V, then there is no phase difference. However, if the output at 17 is not 0V, then there is a phase difference and the phase locked loop of the phase shifter 12 operates to drive the phase difference to zero.

The variable phase shifting circuit 12 is implemented as a series of capacitively loaded logic inverters with variable supply voltages. The capacitive loading increases the propagation delay from the inverter input to the inverter output. The increased supply voltage reduces the inverter propagation delay, thereby reducing the inverter phase shift. A conventional phase-locked loop consisting of Q-channel mixer 17 and associated loop filter 16 drives the Q-channel output of sync detector 30 to zero, thereby ensuring proper phase synchronization for I-channel amplitude detection.

An I-channel mixer 38 of synchronous detector 36 mixes the output of amplifier 32 with the I-channel output of frequency tripler 14 to provide an input signal to level detection circuit 36. The vehicle-side forward path level detection circuit 59 is identical to the ground-side return path level detection circuit 36, except that the former includes a carrier detection function and an associated voltage comparator 138 (fig. 7) that detects the presence of a return path signal.

Fig. 7 shows an embodiment of the receiver level detection circuit 36. A peak hold capacitor 134 driven by a full wave precision rectifier 136 holds the maximum detected voltage level, which in turn is held at a constant value by the AGC circuit 34 (fig. 2). The peak detect voltage with stable AGC amplitude provides a reference voltage for the 1-0 serial binary detect voltage comparator 138 and a reference voltage for the carrier detect voltage comparator 140 by means of the R-2R-R resistor divider 142, which the R-2R-R resistor divider 142 sets the voltage comparator reference voltage to 25% and 75% of the peak value of the post detect waveform shown in fig. 4, respectively. The carrier sense voltage comparator 140 provides a quick indication of the occurrence of a vehicle-side fault. If a fault occurs on the vehicle side, such as a sudden unexpected unload, the return link carrier is immediately disabled. The ground-side apparatus detects carrier removal delayed by only the pre-detection filter delay and the post-detection filter delay, and immediately stops wireless power transmission. The full value of the peak hold function is applied to the AGC integrator 144, and the AGC integrator 144 adjusts the gain of the AGC amplifier 34, and thus the gain of the amplifier 32, to maintain the peak hold capacitor 134 voltage equal to the AGC set point 146 voltage. A conventional precision rectifier 136 generates an output voltage proportional to the absolute value of the input voltage and is comprised of one or more small signal diodes placed in the operational amplifier feedback path, a configuration that effectively eliminates diode forward voltage drops, thereby enabling precision rectification of low level signals with minimal error.

Alternatively, return link synchronization detection may be performed by using coherent, but not phase-synchronized, I and Q detection channels. The amplitude and phase modulation can be extracted in a conventional manner, where the amplitude is the root mean square of the I and Q channels and the phase angle is the arctangent of the ratio of I and Q. In this alternative embodiment, no phase shifting and phase locking circuits are required.

Fig. 1 and 2 show four loop antennas: a pair of transmit and receive antennas 70,80 for the forward link and a second pair of antennas 70', 80' for the return link. In an alternative embodiment, the forward link antenna pair and the return link antenna pair may be combined into a single loop antenna with a conventional antenna duplexer to separate and isolate the forward link signal and the return link signal. Likewise, one or two data link signals may also be multiplexed onto a wireless power transmission coil or onto an auxiliary electromagnetic structure, such as an eddy current generating coil that is part of a coil alignment error detection apparatus described in U.S. patent No. 10,193,400.

For reasons of simplicity and reduced cost, it is desirable that the forward and reverse paths share a common antenna structure. The problem is then that of combining and subsequently separating the forward path and reverse path signals from each other and from other electrical signals encountered by combining the functions into a single antenna structure. Generally, there are two general approaches to achieving signal combining, splitting and routing. The first method uses hybrid transformers, hybrid couplers or directional couplers that distinguish between forward path signals and reverse path signals by means of the direction of signal flow. The second approach relies on a frequency selective filter that distinguishes between signals based on frequency. The frequency-selective multiplexer may be implemented with LC lumped components, distributed components, or as a monolithic circuit containing a plurality of resonant elements and coupling elements. The frequency multiplexing function may combine both signal direction and signal frequency discrimination.

As shown in fig. 8, the performance of the signal multiplexer functional block (circuit) can be enhanced by adding electrical signal cancellation. An electrical signal cancellation function (circuit) is placed in the path between the common forward/reverse path antenna and the receiver. The common antenna is connected to port 202 of a signal splitter 204. A splitter output is passed to the input port of mixer 206 by means of isolation amplifier 208. Samples of the signal to be cancelled are applied to port 210 and the applied signal is phase shifted by variable phase shifter 212 and applied to the local oscillator port of mixer 206 by means of limiting amplifier 214. The output of mixer 206 is applied to loop filter 216 and then to the control port of variable phase shifter 212. The components 212, 214, 206 and 216 form a phase control loop that ensures that the cancellation signal is 90 degrees out of phase with the unwanted signal component applied to the port 202. A zero phase error corresponds to a zero dc voltage at the output of the mixer 206.

As shown in fig. 8, the second output of the splitter 204 goes to a combiner 218 by means of an isolation amplifier 220. As shown, the signal combiner 218, the splitter 222, the isolation amplifier 224, the mixer 226, the loop filter 228, and the attenuator 230 together form an amplitude control loop. A portion of the quadrature sampled signal output by phase shifter 212 is applied to fixed 90 degree phase shifter 232 producing a 180 degree out of phase version of the cancellation signal, which passes through controlled attenuator 230 and into signal combiner 218, where complete cancellation of the unwanted signal is accomplished if the cancellation signal amplitude is correct. A portion of the combiner 218 output signal is directed to the receiver input at 234 via splitter 222. The other portion is directed through an isolation amplifier 224 to a signal port of a mixer 226, the mixer 226 acting as a coherent amplitude detector driven by the unattenuated portion of the 180 degree out of phase cancellation signal. The output of the mixer 226 passes through a loop filter 228 that controls a variable attenuator 230. Those skilled in the art will appreciate that the zero cancellation signal amplitude error corresponds to a zero dc voltage at the output of the mixer 226.

In operation, when a vehicle approaches a wireless charging station, communication is established before charging begins. Once charging begins, full duplex communication is used to regulate and control various aspects of wireless power transfer operation, including the power level transferred, output voltage and current, and monitoring proper system operation. To establish control communications, the surface equipment may continuously or periodically transmit a forward path signal while listening for a vehicle-generated return path signal. Duplex communication is initiated upon detection of a vehicle-generated return path signal. Alternatively, the vehicle-side electronic device may make initial contact with a return path signal that is temporarily derived from a temporary crystal oscillator (not shown) and is detected non-coherently by the ground-side electronic device, rather than with the commonly used carrier recovered by the homodyne detector 50. When the ground side receives the vehicle signal, the ground side device transmits a forward path signal. In the event of vehicle-side communication initiation, the vehicle-side device disables the temporary crystal oscillator and reverts to coherent transponder operation upon successful homodyne detection and carrier recovery.

Both of the above-described start-up methods rely on the transmission of either a forward path signal or a return path signal. It may also be advantageous to initiate communication without either a forward path transmission or a reverse path transmission. In an exemplary embodiment, the ground equipment detects a change in the impedance of the wireless power transfer coil caused by the aerial vehicle and responds by transmitting a forward path signal. This embodiment reduces or eliminates unnecessary signal emissions and is advantageous in some regulatory environments. In addition to the wireless power transfer coil, the initial impedance change may also be detected in a coil alignment auxiliary coil or a near field communication antenna. In addition to impedance changes, changes in the mutual impedance between isolated electromagnetic elements may also be used to initiate communication.

In the exemplary embodiment described herein, the 40.680MHz reverse signal is a simple integer multiple of the 13.560MHz forward signal frequency, where both signals fall within the existing internationally specified ISM-industry scientific medical-frequency assignment. Other frequencies and frequency pairs having non-integer frequency ratios may also be used. For example, two international ISM bands having center frequencies of 2450MHz and 5800MHz may also be used. The coherent repeater architecture described herein, in conjunction with conventional phase-locked loop technology, can generate a 5800MHz signal that is frequency synchronized with a 2450MHz signal having a frequency ratio M/N of 116/49, where M is 5800MHz and N is 2450 MHz. Other combinations of ISM band frequencies and non-ISM band frequencies, frequency pairs with other integer or rational fractional frequencies, and multiple simultaneous transmit and receive carrier frequencies are also possible. For example, multiple return path data channels may also be used, each transmitting data at a different M/N multiple of the transmission frequency of the first inductive link, where M and N are integers. Ground and remote devices linked by far-field propagation (as opposed to near-field propagation) may also use full-duplex frequency coherent communication.

Dynamic charging

Dynamic electric vehicle charging is a special case of providing electric energy to an electric vehicle while the electric vehicle is in motion. As shown in fig. 9, the use of dynamic charging may be achieved using resonant magnetic induction, where multiple independent transmitters 300 are installed in a linear array in the roadway and are energized in a controlled sequence as the target vehicles 310, 312 travel over the linear array 300. Dynamic charging may be achieved when only one vehicle 310 is moving over the array of transmitters 300, or in a more realistic case, when there are multiple electric vehicles 310, 312 of different types, speeds and power requirements moving over the array of transmitters 300. In the latter case, the order of activation of a particular transmitter 300 will be variable within the array and will depend on various vehicle types and their motion, an inherently unpredictable factor. The technical requirements of dynamic charging therefore present special technical challenges. The above system solves a number of problems with dynamic charging as listed below.

The most serious problem with dynamic charging is the need for vehicle-to-ground and ground-to-vehicle communications, where discrete, high-speed, highly differentiated and reliable data is transmitted as a requirement to command and control the charging system. This data is needed to operate the charging system in the case of one or more vehicles that may pass through a series array of inductive power transmitters embedded in the ground.

As shown in fig. 9, an array of inductive power transmitters 300 is mounted beneath the roadway, with each transmitter 300 being placed in a series array along the longitudinal axis of the roadway. The intent is to provide a section of road on which vehicles 310, 312 traveling on the linear array of inductive transmitter 300 can be supplied with electrical power when driven by electric vehicles 310, 312. It is desirable to only energize the transmitter 300 located directly under the vehicle receiver. The transmitter 300 with no vehicle above should remain inactive (i.e., not powered).

In each instance of inductive power transfer, communication between the vehicle-based receiver and the ground-based transmitter occurs, whether in the dynamic charging mode described herein, or in the simpler case of static charging described above, where a vehicle equipped with a single power receiver is parked above a single power transmitter embedded in the roadway and remains stationary. This is desirable for vehicle identification, billing for energy purchase, regulating current and voltage, resonant frequency, vertical gap separation distance, primary to secondary alignment, and other purposes such as safe operation and emergency power outages. This is also true in the case of moving, simultaneously charged mobile vehicles, except that a single transmitter built into the vehicle communicates with multiple independent transmitters in turn. This one-to-one relationship of movement imposes very significant communication challenges.

An operational method for charging a moving vehicle is to energize each individual transmitter 300 in a linear array to create a resonant magnetic field in a sequential pattern as the vehicle receiver 320 passes each individual transmitter 300. The type of vehicle, its specific charging requirements, its speed, alignment with respect to the transmitter 300, and its predicted trajectory are all important factors that make this problem problematic.

As depicted in fig. 9, the determination is the following case: an array of pavement-embedded transmitters 300 will experience the presence of two or more vehicles 310, 312 simultaneously and respond to variable conditions of each vehicle 310, 312. In this case, the communication between each vehicle 310, 312 and the particular surface transmitter 300 over which each vehicle 310, 312 is positioned is discrete and distinct such that no other vehicle 310, 312 is confused or data transmissions from nearby vehicles 310, 312 are received and misread. Requirements for this include that the data communication system is proximally constrained to the target area of the intended vehicle 310, 312. By comparison, broadcast radios and other systems such as Wi-Fi have a range that can be easily received by many nearby vehicles.

The first requirement is to have a high-proximity transmit-receive capability limited to less than 2 meters. (a vehicle moving at 60MPH travels 88 feet per second. the time that the receiver is exposed to the transmitter may be about 0.02 seconds. in this time frame, a time delay of 0.04 to 0.07 seconds in typical signal transmission of digital communication systems is clearly not sustainable.

The second requirement is that there is no or very low time delay (or latency) in the signal. This is desirable because the vehicles 310, 312 can move at high rates over multiple transmitters 300, and discrete communications between the on-board receiver 320 and any one of the transmitters 300 should be ensured.

A third requirement is that the communication system is able to "switch" or sequence communications to the sequencing array of the transmitter 300. This may be accomplished by wiring the transmitters 300 to each other, or by enabling one transmitter 300 to communicate using the near field communication system described herein to address adjacent transmitters 300 in the sequencing array.

The fourth requirement is full duplex operation or bidirectionality to ensure that data can be exchanged in both directions, from vehicle to ground and from ground to vehicle, within a very short time span in which the vehicles 310, 312 are present on the transmitter 300.

A fifth requirement is to allow uninterrupted communication in all weather and environmental conditions. This is accomplished by using magnetic energy, which, as described herein, allows communication through bodies of water, snow, ice, and other harsh road surface conditions.

A sixth requirement is to avoid the problem of multiple antennas away from the vehicles 310, 312. Multiple remote antennas introduce significant problems, such as multipath signal nulls, due to road and body interference. High reliability vehicle identification with multiple antennas makes it difficult to ensure that malicious hacking or other network malicious behavior is avoided.

Those skilled in the art will appreciate that the communication system described herein provides a unified solution for each of these requirements.

As described above, dynamic charging allows a moving vehicle to be charged while traveling as the vehicles 310, 312 pass the transmitter 300 in the road. Each transmitter 300 is energized in a controlled sequence when each transmitter 300 expects the presence of a vehicle 310, 312 above it. Since the vehicle receiver 320 only "exists" for a short time above any one charging station, a sequencing system is required that knows where the vehicle's receiver and the charging station's transmitter are related to each other in real time. Ideally, the pre-sequencing ignition process effectively creates a traveling wave of magnetic energy that moves at the same rate as the vehicle receiver 320. To do this, a communication system with minimal latency is needed, such as the system described herein. As noted above, the communication systems described herein are very fast (near zero latency) and very close so that the position of the receiver 320 relative to the transmitter 300 is known. Thus, in order to achieve dynamic charging, a series of charging stations equipped with the communication system described herein is provided. During operation, each charging station and/or vehicle transmitter provides information to the next transmitter including, for example, vehicle identification, billing for energy purchases, regulating current and voltage, resonant frequency, vertical gap separation distance, primary to secondary alignment, and for other purposes such as safety operation and emergency power outages, location, timing, trajectory, and/or speed information about the vehicle 310, 312 such that the next transmitter ignites when the vehicle's wireless charging receiver 320 is positioned above the transmitter 300 during travel.

Robust hybrid alternative implementation

For Wireless Power Transfer (WPT) systems of the type described herein, there is also a need for a secure and unambiguous point-to-point low latency full duplex link between the ground side charging system and the vehicle side charging electronics. The communication link needs to support Battery Management System (BMS) commands and other communication scenarios between the ground and vehicle electronics.

The supported operational scenarios include static charging and dynamic charging under various weather conditions in the domestic and international markets. Inductively Coupled Communication Systems (ICCS) are reliable in congested radio environments with licensed and unlicensed co-channel users while causing minimal interference. The same inductive communication system is also designed to work with standing water, snow and ice.

In one embodiment, a narrowband full-duplex, low latency, near-field data link for controlling a resonant inductive wireless power transfer system is enhanced by or replaced with a broadband full-duplex, low latency, near-field data link between a ground-side component (GA) and a vehicle-side component (VA). Such improved (hybrid or broadband) wireless duplex data links allow for greater security, higher data rates, dynamic bandwidth selection, frequency agility, and modulation scheme agility to meet local spectral regulations, Electric and Magnetic Field (EMF) security, and data rate requirements for use in near field inductively coupled communication systems.

To support the most widely possible static deployment configuration, the data link should be able to tolerate the interference generated by adjacent or proximate ground-side component placements. Close proximity is impaired over distance (either geographically or vertically in the case of a parking garage) or by shielding structures (e.g. by curbs or floors in a parking garage). The adjacent system may be located in the next vehicle parking space or lane. In some proximity situations, multiple cluster ground components may be deployed in the same parking space or lane service vehicles equipped with corresponding clusters of vehicle components in matching geometries. A contiguous deployment in which a "macro" GA is made up of multiple smaller clusters GA is possible.

In dynamic charging deployment configurations, such as in GA-equipped driving lanes, the data link should tolerate the interference generated by adjacent or proximate ground-side component placements, as well as support soft-switching capabilities between successive ground-side components or clusters of ground-side components. In soft handoff, the charging platform of the vehicle will in turn support multiple data links to a continuous ground component as the vehicle moves in the GA equipped driving lane.

Cluster charger scheme

Modular coil designs are advantageous in customizing WPT systems to meet user demand, where a single coil assembly may be deployed as a stand-alone terrestrial assembly (GA), and where two or more coil assemblies may be clustered to achieve a larger (geometrically) terrestrial assembly capable of higher power transfer. For example, in the case of a bus, truck, train, construction equipment, or any other vehicle requiring wireless power transfer, a cluster of ground-side assemblies and corresponding vehicle-side assemblies (VA) positioned to be mounted in close proximity to each other (e.g., a bus having a VA consisting of 4 adjacently mounted 50kW charging coils, each coil assembly having its own duplex inductive communication) is required, and interference of the communication signal of one coil with the communication signal of an adjacent coil needs to be mitigated.

With this deployment flexibility, the vehicle may have one, two, or more vehicle components installed to allow higher power transfer than can be achieved with a single VA. Similarly, ground components (GA) may be grouped together and selectively enabled to match the geometry of the VA device. In a clustered deployment where a single GA is installed in a close succession to form a single macro GA; the inherent advantage of near field data links in not interfering with other data links in the vicinity is compromised by the inherent radiated power drop range limitation. For a near field inductive communication link, the magnetic field strength and the magnetic field power are 1/(r) respectively³) And 1/(r)⁶) Is decreased (where r is the radius).

Although the radiation magnetic field from the far field of the antenna is only 1/r in magnetic field strength and 1/r in magnetic field energy²Time drops but for distances up to about lambda/2 pi the magnetic near field dominates. For example, the radiation resistance of a magnetically induced near field transmit antenna at 13.56MHz is very small compared to its reactive impedance (typically a ratio less than 0.0005) because most of the energy is coupled in the near field. Thus, the energy propagated in the far field of the magnetic signal is negligible compared to the energy propagated by an equivalent intentional radiation system. The strong drop of the field with distance means that, although care is taken when processing signals from adjacent coils of the same cluster coil assemblyBut there is no concern of interference between coils of adjacent vehicles or charging stations.

FIG. 10 illustrates an example of a cluster deployment in an example embodiment. In this case, a vehicle (e.g., a bus) 1001 is equipped with a cluster vehicle assembly 1004 mounted to the underside of the vehicle 1001. As shown, the passenger stations or parking spaces 1003 are also equipped with respective cluster-deployed floor components 1002.

Figure 11a illustrates signal transmission and components used by an Inductively Coupled Communication System (ICCS)1101 of a Wireless Power Transfer (WPT) system in an example embodiment. Fig. 11a shows a cross-section of ICCS 1101, with a vehicle component (VA)1102 and a ground component (GA)1103 shown as vertically opposed. Other deployment options, for example, horizontal mounting of the VA 1102 on the side of the railcar with the wall-mounted GA 1103, are possible. Any GA to VA orientation can be done in the deployment as long as a close parallel opposition between VA and GA can be achieved. The VA 1102 communication means includes at least one pair of receive antennas 1104 and 1106 located at the periphery of a single transmit antenna 1105. VA receive antennas 1104 and 1106 receive transmissions 1110 and 1111 from GA transmit antenna 1108. Similarly, GA receive antennas 1107 and 1109 receive transmitted signals 1112 and 1113. The bidirectional charging signal 1114 or 1127 may occur at any time during the communication session.

Additional near field receiver antennas may be employed to aid in signal reception and improve the parallelism provided by a full duplex communication system.

Fig. 11b shows an exemplary electric vehicle 1115 from below. In one embodiment, additional receiver antennas may be disposed above VA 1102 or within VA 1102. With at least two antennas in the x-axis (front to back) and at least two antennas in the y-axis (left to right), the VA 1102 will be able to determine GA coil alignment displacements along the x-axis and the y-axis. Preferably, these VA-mounted receiver antennas 1116, 1117, 1118, and 1119 will be placed at the four corners of VA 1102, within the range of the signals 1112 and 1113 of magnetically coupled GA transmitter 1108. The VA coil assembly 1126 for the transmission and reception of the bi-directional charging signals 1114 and 1127 is also located in the VA 1102 nominally located below the transmitting antenna 1105 of the VA 1102. The GA (not shown) architecture replicates the communication antenna and charging coil assembly to mirror that of VA 1102, enabling duplex communication and bidirectional charging.

Note that the additional diversity receiver antennas may also be located anywhere on the vehicle, preferably displaced as far as possible along the length and width of the vehicle, forming secondary distributed antenna/ receiver systems 1121, 1122, 1124, and 1125. Due to the distance of the GA-based transmitter from the distributed antennas 1121, 1122, 1124, and 1125, the receiver antenna can be a magnetic induction loop or a near-field antenna, as indicated by the reactive near-field range and the radiating near-field (also referred to as fresnel zone) range of the signals 1112 and 1113 of the GA transmitter 1108. In some embodiments, the shifted diversity receive antenna may be magnetically coupled through a coplanar, parallel, or orthogonally mounted loop antenna (with the transmitter loop antenna) depending on the distance from the magnetic transmit antenna(s). In cases where the range or coplanar mounting capability of the transmitter to the antenna is uncertain, the magnetic coupling link can also be extended using a hybrid loop antenna with one loop element parallel to the transmitter loop and a second loop element disposed orthogonally.

In the case of dynamic charging, the distributed forward antennas 1121 and 1122 allow for increased communication range, enabling communication with the current GA in the forward direction of the GA. This advanced communication enables the GA to be in the path of vehicle power-up time before the rise-up needs to be minimized. The distributed side antennas right 1122 and 1124 and left 1121 and 1125 also provide center alignment in the direction of travel to maximize coil efficiency.

In one physical embodiment, four or more receiver antennas 1116, 1117, 1118, and 1119 are distributed across VA 1102 in a back-to-front (relative to the forward direction of travel) manner and in a right-and-left lateral manner. Four additional antennas 1121, 1122, 1124, and 1125 are added, 2 of which are attached to the front portion 1120 (e.g., in the bumper, under the bumper, or on the frame), and 2 of which are similarly attached to or embedded in the rear portion 1123. In a front-to-back deployment, the antenna should have the largest possible left and right spacing on the horizontal axis.

The distributed antenna may be backhauled to the ICCS 1101 using a wired or wireless (e.g., bluetooth, Zigbee (IEEE 802.15)) connection. ICCS 1101 will compensate for the different reception and processing times required by the communication link method and data protocol used.

Distributed antennas 1121, 1122, 1124, and 1125 having a common or known offset from the horizontal plane can also achieve improved alignment capabilities. With diversity receivers, location and ranging techniques such as Signal Strength Measurements (SSM), time of arrival (TOA), and time difference of arrival (TDOA) become available. Using directional receiver antennas will implement angle of arrival (AoA) techniques. The vehicle mounted front directional antenna with AoA technology is particularly advantageous for positioning and alignment in the forward direction.

The permanent 79GHz band allocation of Intelligent Transmission Systems (ITS) facilitates hybrid location using TOA, TDOA, AOA, or using two or more of the described techniques. The 12 ITU (international telecommunications union) defined industrial, scientific and medical (ISM) bands are another potential spectrum for alignment (6 are globally available, the other 6 ISM bands are available according to local regulations). The alignment accuracy will vary with the use of higher frequencies providing greater resolution and lower frequencies providing lower resolution.

The use of distributed antennas with TDOA, AOA, or TDOA-AOA hybrid location techniques may be used for the generation of Z-axis (vertical) measurements. In some embodiments, non-radio devices, such as ultrasonic transducer rangefinders, may be used for Z-axis estimation.

Alternatively, if the vehicle is not properly equipped, nominal Z-gaps for make, model, manufacturer and variants may be uploaded from the vehicle or the land-side networking server for setting the wireless power transfer GA voltage and coil enablement in the coil cluster.

Software defined radio

One option for implementing the improved ICCS 1101 is by using software defined transmitters and receivers to improve signal transmission between a ground station and vehicle mounted devices using inductively coupled communication between a ground side assembly (GA)1103 and a vehicle side assembly (VA) 1102.

In an example embodiment, ICCS 1101 is designed to be selectable between two or more types of circuits for amplitude modulation, phase modulation, and frequency modulation, as well as circuits that enable the use of spread spectrum techniques such as direct sequence spread spectrum and Chirp Spread Spectrum (CSS), e.g., binary quadrature keying (BOK), frequency hopping, and Direct Modulation (DM), as desired. As described below, in example embodiments, such features may be implemented in a Field Programmable Gate Array (FPGA), although the functions described may also be deployed using discrete integrated circuit components and/or multi-chip modules and/or software executed by other processing devices, such as Digital Signal Processors (DSPs). In some embodiments, ICCS 1101 may use multiple simultaneous subcarriers as in an orthogonal frequency division multiplexing system (OFDM), where the subcarriers may be allocated to an unlicensed spectrum (or a reserved spectrum) and use any of the modulation schemes described.

Fig. 12a shows functional elements of an ICCS in an example embodiment. As shown, receiver 1201 uses one or more antennas dedicated to magnetic induction signal transmission. As described above, the received analog signal may be filtered in the receiver 1201. The received signal is processed by a digitizing component 1202 to obtain a received analog signal and convert it to a digital representation of the signal. The digital representation of the received signal is then digitally processed by the processing element 1203. The data extracted from the processed signal is then output via the digital interface 1206.

Input digital data may also be applied to the processing element 1203 via the input interface 1207. The input data is packed by the processing element 1203 before being converted to analog signals in the analog conversion element 1204. Once in analog form, the signal may be filtered and transmitted by the transmitter 1205 via one or more antennas dedicated to magnetic induction signal transmission.

In an example embodiment, the ICCS functional elements of FIG. 12a may be implemented in any of a variety of ways. For example, the ICCS may be configured to:

a circuit comprising a discrete Integrated Circuit (IC) (e.g., an analog-to-digital converter (ADC), digital-to-analog converter (DAC)) having programmable elements (e.g., a Field Programmable Gate Array (FPGA), EEPROM, etc.);

hybrid hardware (IC), software, and embedded firmware in a multi-chip module;

firmware residing in an Application Specific Integrated Circuit (ASIC) containing the required control logic, digitizing and analog conversion functions; and

software structures running on a computing platform (e.g., a Central Processing Unit (CPU) or a Digital Signal Processor (DSP)) with accompanying digital-to-analog and analog-to-digital circuitry.

In each case, analog signal filtering may be included as required by the chosen design (e.g., a super-heterodyne design with a bandpass Intermediate Frequency (IF) stage or a direct conversion design with limited analog bandwidth).

The choice of which ICCS implementation (FPGA to DSP) to use and deployment (as a component of a discrete IC, multi-chip IC module, or ASIC) is highly dependent on development costs, throughput, and necessary computational resource costs. In an implementation, the FPGA provides parallel path signal processing, while the CPU/DSP provides excellent memory access and operating system to simplify tasks. Discrete IC packages give maximum flexibility in selecting components and placing them, while multi-chip modules provide a fixed interconnection between discrete components. ASIC packaging is provided in ICCS components and interconnects into a single integrated subsystem at the highest development time and cost, but is the simplest to deploy. In an example embodiment, the ICCS configuration is selected at the time of manufacture, but may also be selected by the user during use.

FIG. 12b shows an example implementation of ICCS 1101 including VA1202 and GA1201 in a discrete integrated circuit implementation. As shown, for the short-range, low-power magnetic field link between GA 1260 and VA 1261, communication channels 1211 and 1227 use magnetic inductive coupling with minimal propagating magnetic fields. GA communication signal 1211 and VA communication signal 1227 may be narrow-band or wide-band depending on preset programming, the phase of the charging cycle (proximity, coarse positioning, fine positioning, Foreign Object Detection (FOD) and field object detection (LOD) scanning, charging, termination of charging), or whether a threshold for signal quality (e.g., received signal strength, bit error rate) has been crossed.

Core 1262 of GA inductively coupled communication system 1260 includes Field Programmable Gate Array (FPGA)1265, analog-to-digital converter (ADC)1263, and digital-to-analog converter (DAC) 1264. FPGA 1265 provides computing resources. Computational operations of the FPGA 1265 include signal processing (e.g., signal summing, combining, and selecting; modulation, demodulation, digital filtering, data extraction, Automatic Gain Control (AGC), and ICCS hardware control). Data from the GA and external systems is input into GA core 1262 via digital interface 1240 for processing for transmission to VA 1261.

A GA core digital-to-analog converter (DAC)1264 is used to convert the digital output bitstream of the FPGA to a quantized analog signal, which is then amplified by transmit amplifier 1208, and then band limited and smoothed by band pass filter 1209, and transmitted by GA transmit antenna 1210, which propagates as an induced magnetic signal 1211.

The signal 1211 of the GA communication traverses an air gap 1266 between VA 1261 and GA 1260, and is then received at VA receiver antennas 1212 and 1213 (note that in this example, two receiver antennas are used, but the design supports the use of a single receiver antenna and any multiple receiver antennas). Once received by one or more of VA's pair-coupled antenna structures 1212 and 1213, the GA signal is band pass filtered using filters 1214 and 1215. The band-limited signal is then amplified by a pair of Low Noise Amplifiers (LNAs) 1216 and 1217, each of which is used in the VA receiver path. A second pair of bandpass filters 1218 and 1219 is then used to limit the signal frequency bandwidth for direct digital conversion on each of the VA receive paths.

Analog-to-digital conversion occurs at VA ADC 1223. VA ADC 1223 may be implemented as a set of ADCs in pairs or as an n-channel ADC (depending on the number of receive antennas used). The digitized signals are then passed to VA FPGA 1222. VA FPGA 1222 converts the received digitized signal using conventional digital signal processing techniques and then processes the reconstructed bit stream (e.g., removing framing, training sequences, implementing forward error correction and data coding (e.g., from coding using convolutional coding, turbo coding, hamming codes), decoding security masked bit sequences), and delivers the bit stream to a Vehicle Battery Management System (VBMS)1239 via a digital interface 1238, potentially through an intermediate processor, network, and protocol such as a controller area network (CAN bus) (not shown). The measurements associated with the communication signals are output to the vehicle-based processor 1250 over the digital interface 1236. The measurement results related to the charging signal are output on digital interface 1237.

Depending on the configuration of the VBMS and the in-vehicle system, a Vehicle Battery Management System (VBMS)1239, vehicle occupant information systems, vehicle entertainment systems, and other in-vehicle data or telemetry systems provide bitstreams to VA FPGA 1222 via digital interfaces 1238 and 1243. VA FPGA 1222 applies framing, training sequences, implements forward error correction and data coding (e.g., using convolutional coding, hamming codes, hadamard codes), encodes security-masked bit sequences, and delivers the bit stream to VA digital-to-analog converter (DAC) 1221. The output of the VA DAC 1221 is then amplified by the transmit amplifier 1224. The VA signal for transmission is then filtered by a band pass filter 1225 to match the desired channel bandwidth. The band-limited analog VA signal is then transmitted over the magnetic field air interface 1266 using the coupled antenna structure 1226.

The induced magnetic signal 1227 of VA is received by one or more of the coupled antenna structures 1228 and 1229 of GA. The VA signal is then band pass filtered on each GA receive path using filters 1230 and 1231. The band-limited signals are then each amplified by a pair of Low Noise Amplifiers (LNAs) 1232 and 1233, each of the Low Noise Amplifiers (LNAs) 1232 and 1233 being used for the GA receiver path. The signal band is then limited using a second pair of bandpass receivers 1234 and 1235 for direct digital conversion on each of the GA receive paths. In some configurations of the ICCS, the band pass filters 1209, 1214, 1215, 1218, 1219, 1225, 1230, 1231, 1234, and 1235 may be configured as a bank of switch filters to accommodate multiple frequency bands.

Analog-to-digital conversion occurs at GA ADC 1263. GA ADC 1263 may be implemented as a pair of a bank of ADCs or as a dual channel ADC. The digitized signal is then passed to VA FPGA 1265. VA FPGA 1265 converts the received digitized signal using conventional digital signal processing techniques and then processes the reconstructed bit stream (e.g., removes framing, training sequences, implements forward error correction and data coding (e.g., using convolutional coding, turbo coding, hamming codes), decodes the security masked bit sequence), and delivers the bit stream to the ground-side computing resources 1241 and external communication interfaces 1242 local to the wireless charger, possibly through intermediate processors, interfaces, and protocols (not shown). In the event a fault event is detected (by the GA) or sent (by the VA), the GA FPGA 1265 signals the emergency shutdown 1244 (e.g., in the event of a coil failure or exceeding a thermal threshold), and the emergency shutdown 1244 disables the charging signal 1245.

Closed and open loop control and reporting

The ICCS 1101 actively measures the charge signal 1245 and the communication signals 1211 and 1227. The measurements may include received signal strength, bit error rate, sum and difference, Eb/No (energy per bit (Eb) to spectral noise density (No)), Received Signal Strength Indication (RSSI), center frequency, and amplitude and phase shifts at the first and second receive antennas 1228, 1229 of the signal 1227 received by the first and second antenna structures 1228, 1229. The measurements may be delivered to a surface or VA digital control interface 1236 via GA digital control interface 1241 for one or more vehicle-based processors 1250 for alignment detection and closed-loop charging system management and control.

Closed loop control may include providing near real time voltage and current measurements (on VA) to FPGA 1222, VA thermal measurements, Z gap changes due to loading or unloading of the vehicle, soft VA or GA fault (cluster) alerts, alerts of intermediate charge performance events, and additional sensing on the vehicle side associated with VA or vehicle electrical system to the GA and VA as needed.

VBMS 1239 uses VA control digital interface 1238 to pass commands for transmission to the charging system, which can command the GA via GA control digital interface 1241.

Spread spectrum wideband signal

In one embodiment, the wideband signal for a full-duplex VA-GA communication link is an asynchronous direct sequence spread spectrum signal using complementary code sequences. In some deployment scenarios, such as where the GA is deployed adjacently as part of a larger macro GA cluster (e.g., as a single vehicle parking space charger), distance cannot be relied upon to provide sufficient magnetic signal attenuation to mitigate co-channel interference between multiple GA-to-VA and VA-to-GA transmissions. The use of spread spectrum sequence techniques allows each of the GA and VA receivers to distinguish the signal transmitted by each receiver from co-channel interference. The use of complementary codes in direct sequence spread spectrum systems is used to allow the receiver to perform correlation processing to overcome co-channel interference and lack of synchronization between the transmitters of the GA and VA.

With sufficient distance between the GA (and the paired VA), the signal attenuation of the magnetic signal allows code reuse, which in turn allows shorter code sequences. With shorter code sequences, the number of "chips" per bit in a direct sequence spread spectrum system can be minimized, resulting in a greater data rate over the same bandwidth.

In communication systems using inductive coupling for transmission, signal reflections and multipath are minimized by the inherent physics of magnetic field propagation. In one embodiment, direct sequence code spreading using complementary code sequences is designed to mitigate co-channel interference between closely located (clustered, adjacent or close) transmitters and receivers, such as in a wireless charging park or lane.

The use of an asynchronous system allows multiple individual surface components (each having its own transmitter and receiver) to be deployed in a contiguous or close proximity without the need for a shared real-time timing source. The lack of a need for a common timing source removes the need for clock recovery and/or phase locking between the GA and VA systems. Thus, each aligned GA and VA pair can communicate independently regardless of the number of deployed units or the number of unit functions. If the GA is not paired with a VA (due to different deployment geometries or VA fault conditions), the GA will not activate the charging signal.

In an example embodiment, such a charging system may be used to charge a vehicle by locating the VA of the vehicle relative to the GA to receive a charging signal. The coils of GA and VA are selectively enabled for charging based on the geometric positioning of VA relative to GA, such that only aligned coils are activated. One or both of the transmission/reception systems of GA and VA are selected to have the same type of signal processing circuit, as appropriate. The transmit/receive system can then be used to transfer charging management and control data between the GA and VA transmit/receive systems over the inductive link during charging.

As described above, the transmit/receive system may include hardware, software, and/or firmware that provides one or more of the following: amplitude modulation, phase modulation, frequency modulation, Orthogonal Frequency Division Multiplexing (OFDM), and spread spectrum implementing techniques including at least one of direct sequence spread spectrum, Chirp Spread Spectrum (CSS), Binary Orthogonal Keying (BOK), frequency hopping, and Direct Modulation (DM). The types of transmission/reception systems are selected to be the same at the time of design/manufacture or by user selection, for example. The VA and GA may then transfer software updates, diagnostic or telemetry information, and/or passenger entertainment service data therebetween during charging.

Figure 13a shows an overhead view of a parking lot based wireless charging station deployed in an example embodiment in a single row geographical arrangement 1301. Parking spaces 1304, 1305, 1306 and 1307 are defined by curbs 1303 and painted line markings, as is typical. The driving lane 1302 provides vehicle access to each parking space. In this example, each parking space 1304, 1305, 1306, and 1307 is installed with a wireless charging floor assembly (GA)1310, 1311, 1312, and 1313. GA 1310, 1311, 1312, and 1313 are shown as clustered components of four adjacent independent GAs, although the length and width of the parking space may be other geometries.

Activities GA1311, 1312, and 1313 radiate magnetic communication signal 1315 before and during each charging session. Due to the coupled magnetic induction signals and the propagation characteristics of the vertical antenna orientation, co-channel interference is confined within the GA cluster and possibly between adjacent parking spaces 1314.

The magnetic signals radiated by each active GA cluster 1311, 1312, and 1313 are one source of co-channel interference for each communication link (in this example, up to 8 signals per cluster, 4 signals from GA to VA when active, and 4 signals from VA to GA). Potential overlaps or collisions of magnetic signals 1315 from nearby parking spaces fitted with active GA 1312 or GA 1313 are also possible, but with sufficient physical separation 1309 between non-adjacent active GA1311 and GA 1312 for greatly reducing or eliminating potential co-channel interference. Possible additional chargers across the travel lane 1302 will have sufficient physical separation 1308 to limit the co-channel interference potential.

Fig. 13b shows a top view of a parking lot based wireless charging station deployed in a dual-bank geographic arrangement 1316 in an example embodiment. The double rows 1316 of GA equipped stops are separated by the travel lanes 1304. In this illustration, parking spaces 1317, 1320, 1321 and 1322 have currently active GAs, while parking spaces 1318, 1319, 1323 and 1324 are inactive (i.e., in an inactive state, the parking spaces may be unoccupied or occupied, but have charging that is not terminated or not yet initiated by operation). Potential co-channel interference from a magnetically coupled full duplex communication system is present in an active vehicle (vehicle radiating magnetic signal 1315). Co-channel interference between each cluster of GA's in the macro GA (here, the macro GA is composed of 4 neighboring GA's, each with independent duplex communication) and potential co-channel interference 1314 between neighboring macro GA's are tolerated by the communication system. The same row-nearest activity GA 1317 and GA 1320 or the cross-row nearest activity GA 1322 and GA 1320 with sufficient geographic isolation 1309 are not potential sources of interference because the potential GA is geographically spaced 1308 across one or more travel lanes 1304 that provide access to the dual-bank charging station 1316.

Enabled communication link

In one embodiment, the full duplex link is always enabled during the charging cycle, providing continuous communication between the VA and GA and secure transfer for vehicle software updates, diagnostics, telemetry, entertainment, and other information. ICCS 1101 supports changes, modulation, and coding of transmit and receive frequencies to support specific events before, during, and after a charging session.

In a clustered deployment, each individual GA may support independent communication links with each individual VA. In this way, the cluster GA can support either individual VA or clustered VA (e.g., 1 row 2 VA; 2 rows 2 VA; 3 rows 2 VA; etc. up to the maximum width and length of the vehicle) or even VA operable by activating only the portion of the charging signal for GA with geometrically corresponding VA. The use of independent communications makes deployment and operation easy, as a single charging station can support multiple configurations of vehicles. Alternatively, the GA may be deployed as a coordinated cluster, where the single GA and VA maintain communication once the charging signal is activated.

Static situation

The duplex communication data link is used to provide authentication and access control for the WPT in both static and dynamic charging scenarios. In addition, the data link may be used to provide information, software updates, diagnostic or telemetry information, and passenger entertainment services between the GA and VA. The continuous nature of the duplex data link produces faster feedback to the control system, such as deactivating the charging signal after detecting the introduction of a foreign substance between the VA and GA. The positioning of the communication system receiver on the physical periphery of the charging coil also allows for the earliest detection of an introduced obstruction.

Dynamic situation

In embodiments of dynamic charging situations, the communication link is maintained as the vehicle moves along the equipped railroad or highway. In this deployment, using Direct Sequence Spread System (DSSS) enabled ICCS, the code sequences are selected to be as short as possible and orthogonal to neighboring GAs, allowing fast soft handover between GAs. Using a magnetic induction communication link, the expected sequence of GAs and associated code sequence can be uploaded to the vehicle to increase the allowable speed on the GAs-equipped travel lane or rail. Using the uploaded sequence, the ICCS can be preloaded to demodulate and decode the communication signal more quickly.

Fig. 14 shows one example of a highway 1401 that can be used for dynamic charging. The highway is provided between two curbs 1402 and 1403, and is divided into a traveling lane 1405 and a charging lane 1406. These charging lanes may have set speeds and set inter-vehicle gap lengths to better optimize charging. The charging lane speed is set to manage the charging time (also referred to as dwell time) on each sequence GA 1407. Vehicles 1404 and 1409 may be moved into a charging lane (shown here as having different lane markings or physical separations 1408), either at will or at designated points of entry.

In the railway example, a sequence or array (sequential clustering) of GA's for charging a VA equipped railcar is placed between the tracks (up to one track gauge width). The GA may also be a VA facing deployed on the side(s) or top of the railcar.

By having multiple GA's arranged sequentially along the travel path, customization of GA's (e.g., longer antennas (charging and communication)) can be deployed and autonomous vehicle control information provided for optimal charging at the current lane and possible charger sites along the possible routes.

Independent communication paths for each component

In one embodiment, a full-duplex inductively coupled data link is deployed for each member of an independent GA (macro GA) cluster. Similarly, each individual VA (part of a macro VA cluster) is equipped with a full-duplex inductively coupled data link.

This independent operation of the data links gives the lowest latency communication by removing the circuitry and processing required to coordinate communication between components when clustering the components. The lack of coordination also means that the link starts faster, as it allows for the implementation of concurrent data link establishment per component pair (GA to VA).

The independent data links also facilitate deployment of single and multiple components. Geometrically arbitrary GA clusters can be deployed in any area or pattern needed to support vehicle size and scaled power supply requirements.

By making each VA and GA functionally identical (e.g., having identical magnetic induction antennas and a common resonant induction coil unit), economies of scale can be realized. The common resonant induction coil unit is also used to improve the efficiency of the charging signal, thereby improving the power efficiency of the ICCS as a whole.

The independent nature of the paired GA-to-VA configuration means that a single GA failure or VA failure in the cluster deployment is gracefully degraded to a lower state of charge via the remaining GA-VA pairs. In one aspect, the failure of the VA cell results in an immediate cut-off of the charging signal from the paired GA. Since the GA is no longer radiating, the vehicle is not heated from the charging signal that is no longer terminated.

Those skilled in the art will appreciate that the topology and circuit implementation methods described herein can be effectively implemented as a single application specific integrated circuit, as a discrete integrated circuit, as a multi-chip module, and/or as software executing on a digital signal processing circuit having ancillary a/D and D/a circuits. Further, while the disclosure contained herein relates to providing electrical power to a vehicle, it should be understood that this is only one of many possible applications, and other embodiments are possible, including non-vehicle applications. For example, those skilled in the art will appreciate that there are many applications that provide full duplex data links in non-vehicle inductive charging applications, such as portable consumer electronic device chargers, such as those used to charge toothbrushes, cellular phones, and other devices (e.g., PowerMat)^TM). Further, those skilled in the art will appreciate that simultaneous amplitude and angle modulation with other complex modulation methods may be used as well as increasing the transmission bandwidth (data rate) of the communication systems described herein by using multiple modulated forward and reverse path carriers. Accordingly, these and other such applications are included within the scope of the claims.

Claims (36)

1. A vehicle charging system, comprising:

a surface assembly comprising one or more coils, wherein each coil has a full-duplex inductively coupled data communication system comprising a first transmit/receive system that transmits a first signal over a first inductive link and receives a second signal over a second inductive link; and

a vehicle component comprising one or more coils, wherein each coil has a full-duplex inductively coupled data communication system including a second transmit/receive system that receives the first signal over the first inductive link and transmits the second signal over the second inductive link,

wherein the first and second transmit/receive systems are adapted to use and switch between circuitry for at least two of: amplitude modulation, phase modulation, frequency modulation, Orthogonal Frequency Division Multiplexing (OFDM), and spread spectrum circuitry implementing techniques including at least one of: direct sequence spread spectrum (CSS), Chirp Spread Spectrum (CSS), binary quadrature keying (BOK), frequency hopping and Direct Modulation (DM), and

wherein the coil of the ground component is configured to be arranged in parallel with the coil of the vehicle component to receive a charging signal during charging and to be selectively activated to match a geometry of the vehicle component during charging.

2. The vehicle charging system of claim 1, wherein the ground assembly includes a processor that processes data from the ground assembly and an external system for transmission to the vehicle assembly and processes data received from the vehicle assembly for delivery to the ground assembly and the external system for processing.

3. The vehicle charging system of claim 2, wherein the processor disables the charging signal when the ground component detects a fault event or when a fault event is received from the vehicle component.

4. The vehicle charging system of claim 1, wherein the vehicle component comprises a processor that processes at least one of commands and data from the vehicle component and from at least one of a vehicle battery management system, a vehicle occupant information system, and a vehicle entertainment system for transmission to the ground component, and processes data received from the ground component for delivery to the vehicle component and at least one of the vehicle battery management system, the vehicle occupant information system, and the vehicle entertainment system.

5. The vehicle charging system of claim 4, wherein the vehicle component further comprises a digital interface, and the processor provides measurements related to the first signal, the second signal, and the charging signal to the digital interface.

6. The vehicle charging system of claim 5, wherein the measurement comprises at least one of: signal strength, bit error rate, sum and difference, energy per bit to spectral noise density ratio, received signal strength indication, center frequency, and amplitude and phase shift at the first and second antenna structures of the vehicle and ground components, respectively.

7. The vehicle charging system of claim 6, further comprising: a vehicle-based processor, wherein the measurements are delivered to the vehicle-based processor via the digital interface for at least one of alignment detection and closed-loop charging system management and control.

8. The vehicle charging system of claim 7, wherein the vehicle-based processor provides the following to the processor for transmission: near real-time voltage and current measurements on the vehicle components, thermal measurements of the vehicle components, Z gap changes due to loading or unloading of the vehicle, a fault alarm of a vehicle component or ground component, an alarm regarding a mid-charge performance event, and additional vehicle sensing data related to the vehicle component or vehicle electrical system.

9. The vehicle charging system of claim 1, wherein the first and second signals are configured as narrowband or wideband signals depending on a phase of a charging cycle or whether a threshold of signal quality has been crossed.

10. The vehicle charging system of claim 1, wherein the first and second signals are configured as asynchronous spread spectrum signals using complementary code sequences.

11. The vehicle charging system of claim 10, wherein the transmit/receive system comprises a direct sequence spread spectrum system that transmits the following code sequences: the code sequence enables each transmitting/receiving system to distinguish a signal from co-channel interference.

12. The vehicle charging system of claim 11, wherein the code sequence is a complementary code sequence.

13. The vehicle charging system of claim 1, wherein the first and second transmit/receive systems are adapted to be selectable among at least one of hardware, software, and firmware configurations adapted to modulate output signals and to modulate input signals.

14. The vehicle charging system of claim 13, wherein the at least one of hardware, software, and firmware is adapted to modulate the output signal using at least two of: amplitude modulation, phase modulation, frequency modulation, Orthogonal Frequency Division Multiplexing (OFDM), and spread spectrum techniques.

15. The vehicle charging system of claim 14, wherein the spread spectrum technique comprises at least one of: direct sequence spread spectrum (CSS), Chirp Spread Spectrum (CSS), binary quadrature keying (BOK), and frequency hopping.

16. The charging system of claim 13, wherein the first and second transmit/receive systems each include a receiver, an analog-to-digital converter, a digital processor, a digital-to-analog converter, and a transmitter, the digital processor processing data from at least one of the surface component and an external system for transmission to the vehicle component and processing data received from the vehicle component for delivery to at least one of the surface component and the external system for processing.

17. The vehicle charging system of claim 16, wherein the analog-to-digital converter and the digital-to-analog converter are implemented as discrete integrated circuits and the digital processor is implemented as a field programmable gate array.

18. The vehicle charging system of claim 16, wherein the analog-to-digital converter, digital processor, and digital-to-analog converter are implemented as firmware residing in an Application Specific Integrated Circuit (ASIC).

19. The vehicle charging system according to claim 16, wherein the digital processor of each transmit/receive system processes input data for transmission and processes data received from other transmit/receive systems using software structures implemented on the digital processor.

20. The vehicle charging system of claim 16, wherein the first and second transmit/receive systems each further comprise at least one band pass filter.

21. A method of charging a vehicle, comprising:

positioning a vehicle component of a vehicle relative to a ground component to receive a charging signal, the vehicle component comprising one or more coils, wherein each coil has a full-duplex inductively coupled data communication system comprising a first transmit/receive system that receives a first signal over a first inductive link and transmits a second signal over a second inductive link, and the ground component comprises one or more coils, wherein each coil has a full-duplex inductively coupled data communication system comprising a second transmit/receive system that transmits the first signal over the first inductive link and receives the second signal over the second inductive link;

selectively enabling the ground component and a coil of the vehicle component for charging based on a geometric positioning of the vehicle component relative to the ground component;

switching at least one of the first and second transmission/reception systems to a signal processing circuit of the same type as a signal processing circuit used by the other of the first and second transmission/reception systems; and

communicating charge management and control data between the first transmit/receive system and the second transmit/receive system over the first inductive link and the second inductive link during charging.

22. The method of claim 21, wherein switching comprises: switching at least one of the first and second transmission/reception systems between at least two of: an amplitude modulation circuit, a phase modulation circuit, a frequency modulation circuit, an Orthogonal Frequency Division Multiplexing (OFDM) circuit, and a spread spectrum circuit implementing techniques including at least one of: direct sequence spread spectrum (CSS), Chirp Spread Spectrum (CSS), binary quadrature keying (BOK), frequency hopping, and Direct Modulation (DM).

23. The method of claim 21, further comprising: communicating at least one of software updates, diagnostic or telemetry information, and passenger entertainment service data between the surface component and the vehicle component via the first inductive link and the second inductive link during charging.

24. The method of claim 21, further comprising: configuring the first and second transmission/reception systems to have the same type of hardware, software and/or firmware adapted to modulate an output signal using at least two of: amplitude modulation, phase modulation, frequency modulation, Orthogonal Frequency Division Multiplexing (OFDM), and spread spectrum techniques.

25. The method of claim 24, wherein the spreading technique comprises at least one of: direct sequence spread spectrum (CSS), Chirp Spread Spectrum (CSS), binary quadrature keying (BOK), and frequency hopping.

26. The method of claim 21, further comprising: communicating at least one of software updates, diagnostic or telemetry information, and passenger entertainment service data between the surface component and the vehicle component via the first inductive link and the second inductive link during charging.

27. The method of claim 21, further comprising: disabling the charging signal when the ground component detects a fault event or receives a fault event from the vehicle component.

28. The method of claim 21, further comprising: the first transmit/receive system processes at least one of commands and data from the vehicle assembly and from an external system for transmission to the surface assembly, and processes data received from the surface assembly for delivery to the vehicle assembly and at least one of the external system.

29. The method of claim 28, further comprising: providing measurements related to the first signal, the second signal, and the charging signal to a digital interface for processing.

30. The method of claim 29, wherein the measurement comprises at least one of: signal strength, energy per bit to spectral noise density ratio, frequency, and amplitude and phase shifts at the first and second antenna structures of the vehicle component and the ground component.

31. The method of claim 30, further comprising: delivering the measurement results to an external processor via the digital interface for at least one of alignment detection and closed loop charging system management and control.

32. The method of claim 31, further comprising: sending at least one of the following from the vehicle assembly to the ground assembly: near real-time voltage and current measurements on the vehicle component, thermal measurements of the vehicle component, Z gap changes due to loading or unloading of a vehicle containing the vehicle component, a fault alarm of a ground component or vehicle component, an alarm regarding a mid-charge performance event, and additional sensed data related to the vehicle component.

33. The method of claim 21, further comprising: configuring the first signal and the second signal as narrowband signals or wideband signals depending on a stage of a charging cycle or whether a threshold of signal quality has been crossed.

34. The method of claim 21, further comprising: configuring the first signal and the second signal as asynchronous spread spectrum signals.

35. The method of claim 34, further comprising: transmitting the following code sequences between the first and second transmission/reception systems: the code sequence enables the first and second transmission/reception systems to distinguish signals from co-channel interference.

36. The method of claim 35, wherein transmitting the sequence of codes comprises: the complementary code sequence is transmitted.

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