KR20220108083A - Method and apparatus for aligning vehicles prior to wireless charging - Google Patents

Abstract

The vehicle alignment system is adapted to align the vehicle with a wireless powered induction coil for wireless charging through the use of magnetic resonance induction. The system includes a transmission line disposed in a parking slot to guide the vehicle to a wireless power induction coil for charging. The transmission line leaks a signal having an operating frequency detected to align the left-right of the vehicle in the parking slot when the vehicle is aligned for charging by the wireless power induction coil. When the vehicle is aligned in the parking slot, at least two in-vehicle antennas mounted on opposite sides of the transmission line detect the operating frequency from the transmission line, and the signal processing circuitry includes a wireless power induction coil and the vehicle's for the parking slot. Detects the relative signal phase between signals detected by the antennas indicating alignment.

Description

Method and apparatus for aligning vehicles prior to wireless charging

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. Patent Application No. 16/723,750, filed December 20, 2019, the entire disclosure of which is incorporated herein by reference.

technical field

This patent application describes a vehicle alignment system related to wireless charging through the use of magnetic resonance induction.

Resonant induction wireless charging uses an air core transformer composed of two concentric coils displaced along a common coil axis. If the primary coil and the secondary coil are not aligned in the axial direction, the transformer coupling coefficient and wireless power transmission efficiency are reduced. For vehicle wireless charging, this means that certain arrangements must be made to ensure that the vehicle parking position is accurate and repeatable to ensure coil axial alignment.

Various details of embodiments of the present subject matter are provided in the accompanying drawings and the detailed description text below.

A vehicle alignment system aligns a vehicle with a wireless powered induction coil for wireless charging through the use of magnetic resonance induction. The system includes a transmission line, which is disposed in a parking slot that leaks a signal having an operating frequency and includes a wireless power induction coil. The transmission line guides the vehicle to a wireless power induction coil for charging. At least two in-vehicle antennas mounted on each side of the transmission line and typically symmetrically with respect to the transmission line when the vehicle is aligned in the parking slot detect a signal leaking from the transmission line. The signal processing circuitry detects the relative signal phase between signals received by the antennas on opposite sides of the transmission line. The relative phase differences between the detected signals from the antennas indicate the left-right alignment of the vehicle with respect to the transmission line.

In sample embodiments, the vehicle alignment system aligns a first wireless powered induction coil of a vehicle with a second wireless powered induction coil in a parking slot for wireless charging through the use of magnetic resonance induction. The system includes a ground assembly disposed in the parking slot. The grounding assembly may include a wireless charger including one or more wireless charging coils and a magnetic inductive resonance communication transceiver, and a beacon signal source for transmitting a beacon signal. The system further includes a transmission line coupled to the ground assembly and disposed in the parking slot that leaks a signal having an operating frequency detected by the vehicle to guide the vehicle to a second wireless power induction coil for charging. In sample embodiments, the transmission line comprises a continuous wired monopole antenna disposed in a folded pattern with respect to the ground assembly or a converging wired dipole antenna having first and second sections extending away from the ground assembly. In operation, the vehicle detects a signal having an operating frequency leaking from the transmission line using at least two in-vehicle antennas mounted on opposite sides of the transmission line when the vehicle is aligned in the parking slot, and the at least two vehicles Each signal detected by the onboard antennas is processed to determine the relative signal phase between each signal representing the vehicle's left-right alignment with respect to the transmission line. The transmission line may be disposed along the centerline of the parking slot, or may be parallel to but offset from the centerline of the parking slot. The transmission line may also curve along the trajectory to guide the vehicle to the ground assembly in the parking slot. In sample embodiments, the operating frequency is 40.68 MHz or 13.56 MHz.

In further sample embodiments, a first end of the continuous wired monopole antenna is coupled to a ground assembly and is offset on a first side of a centerline of the ground assembly. A second end of the continuous wired monopole antenna is adjacent the ground assembly on a second side of the centerline of the ground assembly. The continuous wired monopole antenna also includes first and second sections extending substantially parallel on first and second sides of a centerline of the ground assembly.

In other sample embodiments, first and second sections of a converging wired dipole antenna extending away from the ground assembly are parallel to each other and offset on respective sides of a centerline of the ground assembly, the first and second sections of the first and second sections The ends are connected to the ground assembly.

In still other sample embodiments, the leaky transmission line is coupled to the ground assembly and extends away from the ground assembly beyond an end of the transmission line remote from the ground assembly. In such embodiments, a beacon signal source of the ground assembly pulses a beacon signal on a leaky transmission line and provides a continuous beacon signal on a transmission line comprising a continuous wired monopole antenna or a converging wired dipole antenna.

In still other sample embodiments, the transmitter is provided at the end of the leaky transmission line remote from the ground assembly. The transmitter receives data from the ground assembly over the leaky transmission line and broadcasts at least a portion of the data received from the ground assembly. The data broadcast by the transmitter at the end of the leaky transmission line includes the power levels provided by the grounding assembly, the power types available in the grounding assembly (AC/DC), the connector types supported by the grounding assembly, the grounding. forms of payment accepted by the assembly, whether the wireless charger of the grounding assembly is in use, and/or the amount of time remaining in the charging session being performed by the grounding assembly.

According to other aspects, a method is provided for aligning a first wireless power induction coil of a vehicle with a second wireless power induction coil in a parking slot for wireless charging through the use of magnetic resonance induction. The method includes providing, by a grounding assembly disposed in the parking slot, a beacon signal to a transmission line disposed in the parking slot to guide the vehicle to a second wireless power induction coil for charging; a transmission line leaking a beacon signal at an operating frequency, the transmission line comprising a converging wired dipole having a continuous wired monopole antenna disposed in a folded pattern with respect to a ground assembly, and first and second sections extending away from the ground assembly containing one of the antennas -; aligning the left-right of the vehicle in the parking slot with respect to the transmission line for charging by the second wireless power induction coil, the aligning being mounted on opposite sides of the transmission line when the vehicle is aligned in the parking slot detecting a beacon signal at an operating frequency at which the at least two in-vehicle antennas are leaking from the transmission line; and adjusting the alignment of the vehicle with respect to the second wireless power induction coil based on the relative signal phase between respective signals indicative of the left-right alignment of the vehicle with respect to the transmission line.

In sample embodiments, the method includes connecting a first end of a continuous wired monopole antenna to a grounding assembly and offsetting the first end on a first side of a centerline of the grounding assembly, first and second sections of the continuous wired monopole antenna extending substantially parallel on the first side and on the second side of the centerline of the grounding assembly, and placing a second end of the continuous wired monopole antenna adjacent the grounding assembly on the second side of the centerline of the grounding assembly. further includes

In other sample embodiments, the method includes arranging first and second sections of a converging wired dipole antenna parallel to each other such that they are offset on respective sides of a centerline of the ground assembly, and and connecting the first ends to the grounding assembly.

In still other sample embodiments, a method includes connecting a leaky transmission line to a ground assembly such that the leaky transmission line extends away from the ground assembly beyond an end of the transmission line remote from the ground assembly. In such embodiments, the ground assembly pulses a beacon signal on a leaky transmission line and provides a continuous beacon signal on a transmission line comprising a continuous wired monopole antenna or a converging wired dipole.

In still other sample embodiments, a method includes providing a transmitter at an end of a leaky transmission line remote from a ground assembly, the transmitter receiving data from the ground assembly via the leaky transmission line, and the transmitter receiving from the ground assembly and broadcasting at least a portion of the data being processed. In sample embodiments, the transmitter provides power levels provided by the grounding assembly, the power types available in the grounding assembly (AC/DC), the connector types supported by the grounding assembly, and the form of payment accepted by the grounding assembly. Broadcast data, including whether the wireless charger of the grounding assembly is in use, and/or the amount of time remaining in a charging session being performed by the grounding assembly.

As discussed herein, logic, commands, or instructions implementing aspects of the methods described herein may be provided to a computing system including a processor, memory, and a wired communication subsystem. Another embodiment discussed herein includes the incorporation of the techniques discussed herein into other forms including programmed logic, hardware configurations, or other forms of specialized components or modules, which include such an apparatus having respective means for performing the functions of the techniques. Each of the algorithms used to implement the functions of these techniques may include a sequence of some or all of the electronic operations described herein or other aspects illustrated in the accompanying drawings and the detailed description below. Such systems and computer-readable media containing instructions for implementing the methods described herein also constitute sample embodiments.

This Summary section is provided to introduce aspects of the subject matter in a simplified form, wherein a further description of the subject matter follows the text of the Detailed Description. This summary section is not intended to identify essential or required features of the claimed subject matter, but it is not intended that the specific combination and order of elements listed in this summary section provide limitations on the elements of the claimed subject matter. It is not intended to be Rather, it will be appreciated that the following section provides summarized examples of some of the embodiments described in the detailed description below.

The foregoing and other advantageous features and advantages of the systems and methods described herein will become apparent from the following detailed description taken in conjunction with the accompanying drawings:
1A shows a representation of an alignment system comprising a vehicle parking slot with an inductive wireless power transmission coil, and a transmission line coincident with the parking slot centerline.
1B shows a representation of a vehicle parking lot, with an alignment system comprising angled parking slots, inductive wireless power transmission coils, and curved transmission lines to help guide the vehicle to an appropriate location within the parking slot for charging.
Figure 1c shows that after a turn the bus approaches the inductive charging position, thereby ensuring an appropriate trajectory for the long curved transmission line of the alignment system to be aligned in the charging coil.
Fig. 2a shows a conceptual representation of a device for vehicular parking alignment according to a sample embodiment.
2B shows a representative relationship between vehicle antenna phase difference and vehicle alignment.
3A shows an embodiment of a transmission line and parking slot radio frequency source implemented as a 300 ohm balanced transmission line.
3B shows an alternative embodiment of a transmission line and parking slot radio frequency source implemented as a terminated 50 or 75 ohm coaxial cable with specially designed slots in the outer conductor or shield.
4 shows an embodiment of an antenna commutation switch and associated circuitry;
5 shows an embodiment of the post FM receiver signal processing circuitry.
6 shows an alternative embodiment of an alignment system for an approach to a magnetic induction resonant wireless charger in a typical pull-in parking stall.
7 shows another alternative embodiment of an alignment system for an approach to a magnetic induction resonant wireless charger in a typical pull-in parking lot.
8A shows a folded wired dipole antenna having at one end a ground assembly hosting a beacon signal source.
FIG. 8B shows a graphical representation of the signal error function of the folded wired dipole antenna illustrated in FIG. 8A .
9A shows a converging wired dipole antenna having at one end a ground assembly hosting a beacon signal source.
Fig. 9B shows a graphical representation of the signal error function of the converging wired dipole antenna illustrated in Fig. 9A;
10A shows wireless power using both a leaky transmission line to provide initial guidance, and a half wave 'converging antenna' for ranging and alignment from the antenna end to the wireless charging pad of the ground assembly. A vehicle alignment system is shown for transmission positioning.
FIG. 10B shows a graphical representation of a signal error function of the vehicle alignment system illustrated in FIG. 10A .

Systems and methods of the present invention may be more readily understood by reference to the following detailed description taken in connection with the accompanying drawings and examples, which form a part hereof. It is to be noted that the systems and methods are not limited to the specific products, methods, conditions, or parameters described and/or shown herein, and that the terminology used herein is by way of example only and is intended to describe specific embodiments. It is to be understood that these are for the purpose of this disclosure and are not intended to be limiting. Similarly, any description of a reason for an improvement or mode of a possible mechanism or action is intended to be exemplary only, and the systems and methods described herein are not intended to represent a mode or improvement of any such proposed mechanism or action. shall not be constrained by the correctness or inaccuracy of reason for It is recognized that throughout this text, descriptions refer to both methods and software for implementing such methods.

A detailed description of exemplary embodiments will now be described with reference to FIGS. 1 to 10 . While this description provides detailed examples of possible implementations of the systems and methods described herein, it should be noted that these details are intended by way of example only and not limitation of the scope of the claimed invention.

The functions described herein may, in one or more embodiments, be implemented, at least in part, in software. Software may consist of computer-executable instructions stored on a computer-readable medium or computer-readable storage device, such as one or more non-transitory memory or other tangible hardware-based storage device, local or networked. Also, these functions correspond to modules, which may be software, hardware, firmware, or any combination thereof. Numerous functions may be performed in one or more modules as desired, and the described embodiments are merely examples. The software may be executed on a digital signal processor, ASIC, microprocessor, or other type of processor running on a computer system, such as a personal computer, server, or other computer system, turning such computer system into a specifically programmed machine. have.

1A is a schematic representation of a car parking slot 10 . While the wireless power transfer primary coil 12 is shown near the head of the parking slot 10 , the wireless power transfer primary coil 12 may also be located at the foot of the parking slot 10 or other within the parking slot boundaries. can be located where Regardless of the primary coil position, the vehicle must be parked within the marked boundaries of the parking slot 10 . A buried or surface mounted transmission line 14 extends along the parking slot centerline. This transmission line 14 connected to a low power continuous wave radio frequency source 20 ( FIG. 2 ) transmits a localized radio frequency field used by onboard electronics to determine vehicle alignment within the perimeter of the parking slot 10 . create The transmission line 14 may differ in length and direction, as shown in FIGS. 1B and 1C which are longer and more curved, from the short and straight embodiment shown in FIG. 1A .

1B is a representation of a series of angled parking slots 10 . A wireless power transfer primary coil 12 is shown in each of the angled parking slots 10 near the head-end. A buried or surface-mounted transmission line 14 runs within the parking slot along a centerline and extends out of the parking slot so that the vehicle travels along the trajectory to guide the vehicle to the wireless power induction coil 12 in the parking slot 10 . curved into the lane of Vehicle 15 travels in a right-to-left direction and receives alignment signals from low power continuous wave radio frequency source 20 (FIG. 2) and a transmission line for an appropriate slot in which charging primary coil 12 is available. Vehicle 15 uses the alignment signal from transmission line 14 in conjunction with receive antennas on vehicle 15 as described below with respect to FIG. 2 .

1C is a representation of a bus 16 accessing a wireless inductive charging station including a wireless powered induction coil 12 after completing rotation. It is important that the bus 16 is properly aligned in the wireless power induction coil 12 and that an appropriate turning radius and location is important in achieving an accurate trajectory. In this example, the transmission line 14 is several tens of feet long and is embedded in the roadway 17 in the proper orientation to consistently guide the bus 16 along the correct path for proper alignment in the charging coil 12 . has been

2A is a block diagram representation of an alignment electronics. On the ground, there is a radio frequency source 20 and a transmission line 14 of a certain length. The vehicle has two small antennas 22, 24 mounted equidistant to the left and right of the vehicle centerline. If the offset in the detected phase offset is taken into account, one of ordinary skill in the art will understand that the antennas 22 and 24 may also be offset (not the same distance). The antennas 22 , 24 are connected to the antenna switch 28 by a coaxial cable 26 . Antenna switch 28 is controlled by antenna rectification clock 30, which then alternately connects one antenna and the other antennas 22, 24 to a conventional frequency modulated radio receiver 32. In the sample embodiment, the commutation signal is a 50% duty cycle square wave.

The rectifying action of the antenna switch 28 when the two receive antennas 22 , 24 are positioned equally away from the transmission line 14 , such as when the vehicle is symmetrically aligned within the perimeter of the parking slot 10 . does not affect the receiver signal. The amplitude and phase of the two antenna input signals 31 are the same, and there is no response from the receiver 32 . However, if the vehicle is misaligned within the parking slot 10 , the vehicle antennas 22 , 24 are no longer symmetrical with respect to the transmission line 14 . The antenna switching action then introduces signal amplitude and phase perturbations at the commutation rate. A signal from an antenna closer to the transmission line 14 will have a larger amplitude and leading phase with respect to a farther antenna. Frequency modulated receiver 32 ignores amplitude perturbations but detects phase perturbations, where frequency is the time rate of phase change, thereby replicating the antenna switch rectified signal at receiver audio output 34 . The receiver audio rectified signal replication is altered by the limited receiver bandwidth. If the rectified signal frequency is above the receiver recovered audio passband, then there is no recovered rectified signal. If the rectified signal frequency is just above the lower receiver audio passband frequency, the recovered rectified signal will approximate the original rectified square wave even if it is low pass filtered by the receiver upper audio passband limit. The rectified signal frequency in the upper half of the receiver audio passband results in a largely sinusoidal recovered audio signal.

As further illustrated in Fig. 2a, the audio output 34 is provided to a sync detector 36 to detect phase differences between the respective antenna signals, the output signals representing any misalignments are determined whether the signal is leading or lagging. It is provided to a voltage comparator 38 to determine the alignment error polarity based on whether it has a lagging phase, and to an absolute value detector 40 to determine the magnitude of the alignment error. In sample embodiments, the alignment error polarity and alignment error magnitude signals are provided to a display device and other audiovisual means to provide feedback to the driver for steering the vehicle in the parking slot 10 relative to the wireless powered induction coil 12 . to provide.

2B shows an exemplary representation of the phase differences between the respective alignment antennas as a function of alignment error or displacement from the centerline.

The system maximum operating frequency provided by the radio frequency source 20 is set by the spacing between the two vehicle-mounted antennas 22 , 24 which must be less than the width of the vehicle. In the United States, the average parking slot width is about 9 feet. Cars are typically no wider than 8 feet. To avoid phase ambiguity, the two sense antennas 22 , 24 should be spaced apart no more than λ/2 at the operating frequency. For two sense antennas separated by 8 feet, the maximum system operating frequency is about 61.5 MHz. Higher frequencies and narrower antenna spacing are possible if the vehicle driver can assume entering a parking slot with an initial alignment error of less than ½ of the parking slot width. Higher operating frequencies are also possible with the use of more than two vehicle-mounted antennas, with an additional antenna or antennas used to resolve the phase ambiguity. Those of ordinary skill in the art will recognize that there is no lower bound on the system operating frequency, except that the signal-to-noise ratio of the alignment error progressively deteriorates as the operating frequency is lowered.

The apparatus described herein provides vehicle left-to-right alignment with respect to a parking slot centerline. The vehicle left-right misalignment is indicated to the driver by visible, audible, or tactile means. The visual indication may be an illuminated indicator, a graphical display, or a software generated graphical overlay imposed on the video camera image. The audible indication may be a continuous or pulsating sound or a software generated speech synthesizer. Tactile indications are indicated by a vehicle steering wheel or steering mechanism, a gear shift lever, the driver's seat, or via the vehicle floor, or floor mounted vehicle control pedals. may be provided via vehicle control pedals. For example, using the driver visual cues or technical means described in U.S. Provisional Patent Application Serial No. 61/862,572, filed August 6, 2013, the driver can use the parking slot ( 10) For axial coil alignment in fore-and-aft directions to ensure that it is fully retracted, it is possible to indicate and control where the aligned vehicle should stop.

3a and 3b show sample embodiments of transmission line 14 . In particular, FIG. 3A shows a buried or surface mounted transmission line 14 and a radio frequency source 20 leaking a signal at the operating frequency. In this embodiment, a 40.68 MHz, 50-ohm impedance continuous wave radio frequency source 20 provides radio frequency excitation. A power level of about 1 mW is used. Mini-circuits RF transformer 42, model number ADT 4-6T, is used as impedance matching balun. The transmission line 14 is implemented as a normal 300-ohm characteristic impedance balanced transmission line of a certain length. This transmission line is not designed to be leaky, but there is enough leakage to be picked up by the antennas 22 and 24 in the sample embodiments. A 300-ohm resistor 44 terminates the end of the balance line to eliminate reflections and standing waves. Transmission lines do not need to be balanced; A leak unbalanced coaxial line would be equally suitable. Alternatively, other transmission line impedances may equally be used, such as a 50 or 75-ohm coaxial cable with slots in the outer shielding. Figure 3b shows an unbalanced 50 or 75 ohm coaxial cable transmission line 14' with specially designed slots 43 and a terminating resistor 45 matched to the characteristic impedance of the coaxial cable.

FIG. 4 shows the circuitry associated with the antennas 22 and 24 of FIG. 2 , the antenna rectification switch 28 , and the rectified clock 30 . In the sample embodiments, antennas 22 and 24 include rectangular spirals fabricated on a printed circuit board to ensure antenna-to-antenna consistency. The number of turns for the rectangular helix depends on the desired inductance value for the antenna to resonate with the capacitance to achieve the desired response at the operating frequency. In the sample configuration, 10 turn rectangular spirals were used for antennas 22 and 24 . The antennas 22 and 24 are electrically small and do not resonate at the operating frequency without the use of additional capacitance. Each antenna 22 , 24 is connected to a length of conventional 50-ohm characteristic impedance coaxial cable 26 . The two cables 26 are of equal length when the antennas are symmetrically spaced relative to the centerline of the vehicle, and serve as baluns to suppress RF currents that would otherwise be induced on the cable outer conductors. The two cables 26 each have a ferrite sleeve 46 comprising several ferrite beads that slide over the cable 26 at the ends connected to 22 and 24 . Induced RF currents introduce significant system errors and must be suppressed. An operating frequency of 40.68 MHz is used in the sample example. This frequency is nearly optimal for this application, and ISM ( Industrial, Scientific and Medical) nationally and internationally. ISM frequencies are reserved for non-communication uses, but may also be used for communications if users are willing to accommodate the possibility of radio interference from primary ISM applications. The advantage to doing so is significantly reduced, equipment certification and spectrum allocation regulatory burdens. Since the maximum range of the vehicle alignment system described herein is a few feet at most, the probability of radio interference from other 40.68 MHz ISM frequency users is quite slim.

An RC oscillator 30 consisting of two logic inverters 48 and resistors R6 and R7 together with a capacitor C6 generates a rectangular wave signal twice the desired antenna commutation frequency, which in turn is It is divided by two by the D flip-flop 50, thus generating a rectified clock at the desired frequency with a 50-50 duty cycle. Components R1, R3, R4, D1, D2, and L1 include a diode RF switch 28 controlled by Q and not Q flip-flop outputs. R2, R5, C4, and C5 limit switching transients by slowing the leading and trailing edges of the switch control waveform. R8, C8, and associated logic inverters 52 delay the antenna rectified clock control signal to compensate for receiver delay. C1, C2, and C3 are AC (alternating current) coupling capacitors, which block DC (direct current) signals but pass RF (radio frequency) signals. C7 is a bypass capacitor that filters RF noise from the voltage source of the D flip-flop 50 .

5 shows the post receiver signal processing circuitry. The output of the antenna rectification switch 28 goes to the antenna input of a conventional narrowband FM receiver 32 . The circuitry includes a consumer-grade pocket-sized scanning receiver, the Uniden BC72XLY compact scanner, but any narrowband VHF FM receiver implementation, analog or digital, hardware or software, is acceptable. The vehicle alignment error appears in the receiver audio output as a bandwidth-limited square wave at the antenna rectified clock frequency. The square wave size represents the size of the alignment error; The square wave polarity indicates the direction of the alignment error, either left or right. Sync detection then generates a DC voltage, having an amplitude proportional to the alignment error and a polarity indicative of the alignment error direction.

Two operational amplifiers 54 amplify the audio signal from the FM receiver by gains of one and minus one. Integrated circuit 56 includes three single-pole double throw (SPDT) CMOS FET switches, one of which is used as a synchronous rectifier driven by a delayed antenna rectification switch control signal. A low-pass filter 58 consisting of a resistor R16 and a capacitor C11 follows the SPDT switch 56 and removes all commutation frequency ripples, with an amplitude proportional to the vehicle misalignment and the vehicle to the left or right of the parking slot centerline. It leaves a DC signal, with a polarity determined by the direction of the alignment error. The absolute magnitude circuit 40 recovers the magnitude of the vehicle displacement error, while the voltage comparator 38 determines the error polarity.

The two operational amplifiers 60 and 62 are used as post RC low-pass filter buffer amplifiers and as a zero-reference voltage comparator, respectively. The components associated with transistor 64 keep the op amp section free from voltage saturation, avoiding subtle problems sometimes experienced when using op amps in open-loop connections as voltage comparators. Voltage comparator 38 implemented by operational amplifier 62 provides a logic level signal indicating the polarity of the alignment error, either left or right. The operational amplifiers 66 and associated components include an absolute value detector 40 that provides a unipolar representation of the magnitude of the alignment error independent of the polarity of the post sync detector signal.

In the implementation described above, the vehicle dual sensing antennas 22 and 24 and the transmission line 14 are mounted along the vehicle centerline and the parking slot centerline, respectively. Offset positions that may be required to avoid vehicle underbody and parking slot obstacles can be accommodated by including appropriate offset correction in the post sync detector hardware or software. In the latter situation, the required offset correction is provided by the ground-to-vehicle communication link.

Alternative embodiments

As alternative embodiments, more complex antenna shapes and additional antennas embedded within the pavement or attached to the pavement surface may be implemented to add functionality to the vehicle alignment system. This added functionality includes the ability to determine the approximate distance, speed, and deceleration rate for a Ground Assembly (GA) charging pad as the vehicle approaches using the same on-board receiver and antenna. The distance, speed, and deceleration rate may be provided to the vehicle controller or the vehicle controller may calculate these values from the provided measurements. In such embodiments, a radio frequency source (colocated or integrated within the GA) may generate a continuous wave beacon signal or pulsed or otherwise modulated output on the antennas. As previously described, an error function using both the received signal strength and the received phase can be used for alignment when the leak line is implemented.

It is noted that the right and left indications in the following figures are from the perspective of an approaching vehicle and are for illustrative purposes only and may be reversed in application. For example, the left and right sides are reversed when the vehicle is reversing into a parking section. The X and Y axes are defined as in ISO 4130. All examples use a 'pull-in' or 'pull-forward' perspective for consistency. When using the 'reverse-in' parking method (the vehicle reversing into the parking compartment), the left-right directions will be reversed. 6 depicts an embodiment of one such improved alignment mechanism for an approach to a magnetic induction resonant wireless charger in a typical (eg, 90°) pull-in parking compartment. The same mechanism may be deployed in other parking arrangements, such as 45° parking sections or pull-up (parallel parking) curbside space(s). A “folded” or “semi-elliptical antenna” provides alignment service to vehicles entering a parking space from all directions (straight, right, or left).

Parking section 601 is an area defined by pavement lanes, columns, curbs, or other indicia. A grounding assembly (GA) 602 (a wireless charger comprising one or more wireless charging coils and auxiliary magnetic inductive resonant communication transceiver(s)) is arranged to be accessible to incoming vehicles (in various countries, a GA within a parking compartment). It should be noted that the placement of may be affected by local regulations, the types of vehicle(s) to be serviced, and local parking practices). The folded continuous wired monopole transmit antenna 603 consists of a left section 604 and a right section 605 . The transmit antenna 603 is placed to form a folded or semi-elliptical pattern (attached to a surface or embedded in a pavement), and the signal and antenna are directed at the centerline 606 of the GA 602 toward the incoming direction 607 . It starts at a location near and ends adjacent to GA 602 on opposite sides of centerline 606 . Depending on the length of the parking section 601 and the frequency used, the monopole antenna 603 may extend the entire or fractional wavelength. For example, using an ISM frequency of 13.56 MHz, a full-wave antenna of 22.11 meters would allow for a folded deployment of less than 11 meters over the overall length 608 . The spacing of the parallel sections of the transmit antenna 609 is such that the vehicle-mounted receiver antennas 22 , 24 are inside the transmit antenna sections 609 after the vehicle has rotated from the driving direction 610 to the parking compartment 601 . will do

7 depicts another embodiment of an improved alignment mechanism for an approach to a magnetic induction resonant wireless charger in a typical (eg, 90°) pull-in parking compartment. The same mechanism may be deployed in other parking arrangements, such as 45° parking sections or pull-up (parallel parking) curbside space(s). The “converging antenna” design shown in FIG. 7 provides alignment services to vehicles entering the parking space from any of the right, left, or straight forward directions.

Parking section 701 is an area defined by pavement lanes, posts, curbs, or other indicia. A grounding assembly (GA) 702 (a wireless charger comprising one or more wireless charging coils and an auxiliary magnetic inductive resonance communication transceiver(s)) may be of a pull-in, back-in, or parking compartment type (45°, 90° , parallel or curbside) arranged to be accessible to incoming vehicles for parking (in various countries, the placement of GAs is influenced by local regulations, the types of vehicle(s) to be serviced, and local parking practices). can be received). The converging leakage line transmission antenna vehicle alignment system of FIG. 7 allows access from either the traveling direction 710 or the straight forward direction 707 . Although not shown, the use of a converging leaky line transmit antenna vehicle alignment system for parallel or curveside use is supported.

The converging wired dipole antenna 703 includes a left section 704 and a right section 705 . A leaky line-based transmit antenna 703 is placed (attached to a surface or embedded in a pavement) to form a parallel pattern, where both the signal and the antenna are positioned at the centerline 706 of the GA 702 GA ( 702) from a co-located or integrated transmitter. Depending on the length of the parking section 701 and the frequency used, the monopole antenna 703 may extend the entire or fractional wavelength. For example, using an ISM frequency of 13.56 MHz, a full-wave antenna 703 of 22.11 meters allows placement just above 11 meters, resulting in an overall length 708 of 5.5 meters. Physical antenna segmentation 709 occurs next to GA 702, and the apparent distances in FIG. 7 are exaggerated for illustrative purposes.

Asymmetric placement (around centerline 706 ) of transmit antenna 703 (around centerline 706 ) is also considered when the offset(s) are known for compensation of received signal characteristics (eg, received signal strength and signal phase).

8A shows a folded wired dipole antenna 802 . One end of the folded dipole antenna 802 is a GA 801 that hosts a beacon signal source. Centerline 804 of GA 801 depicts the y-axis point at which the vehicle's VA (Vehicle Assembly) resonant inductive coil center should be located for maximum wireless power transfer efficiency. Antenna 802 extends to the limit of ½ of a wavelength (or ¼ of a wavelength if implemented as a half-wave antenna) in a direction opposite to the approach direction. The curved end 803 of the folded antenna 802 serves as a signal acquisition threshold 806 , where both receiver antennas 22 , 24 are a beacon signal indicating the start of the antenna 802 irrespective of the approaching vehicle angle. can be reliably detected. The GA-to-antenna threshold 805 is the point at which the signal transmitted by the wired dipole antenna 802 represents the end of the antenna 802 .

FIG. 8B shows a graphical representation of the signal error function of the folded wired dipole antenna illustrated in FIG. 8A ; The X-axis 809 shows the range while the Y-axis 808 shows the relative beacon signal phase difference 807 between the receiver antennas 22 , 24 . As the vehicle moves over the end 803 of the folded wired antenna 802 , both receiver antennas 22 , 24 begin to receive a beacon signal. At this first signal acquisition detection threshold 806, the received beacon amplitude and phase are approximately equal, minimizing the error function. After the right antenna 24 and the left antenna 22 have passed through the initial obscured area around the end 803 of the antenna 802 (moving towards the GA 801 ), the right VA receiver antenna 24 and the left VA The phase of the signal received by the receiver antenna 22 begins to diverge.

As the vehicle continues toward GA 801, the system uses the signal strengths at the right receiver antenna 24 and left receiver antenna 22 to provide an indication of vehicle Y-axis alignment while the right receiver antenna ( 24) and the divergence of the signal phase at the left receiver antenna 22 are used to provide a vehicle X-axis indication. Vehicle X- and Y-axis indications (and potentially calculated speed and deceleration) are periodically communicated to the driver, driver-assisted, or fully automated driving system to control steering and braking.

As the vehicle continues toward GA 801, the vehicle alignment system continues to use the received signal strengths at the right receiver antenna 24 and left receiver antenna 22 to provide a Y-axis alignment indication, while the right The divergence in the received signal phase at receiver antenna 24 and left receiver antenna 22 approaches 180° at antenna origin 805 . At the antenna threshold position 805 where the phase is equal to 180°, the relative signal strength is reduced to zero between both the receiver antennas 22 and 24 to provide a secondary indication that the antenna threshold 805 has been reached, thus It is expected to provide a clear indication that the edge of GA 801 has been reached and the final precision positioning system can be activated to cover the distance 805 to 804 , or the vehicle speed at the antenna threshold 805 is It can be used to estimate when it should be at zero velocity to be positioned above the GA centerline 804 . The final position determination at distance 810 from GA edge 805 to GA centerline 804 (eg, "METHOD OF AND APPARATUS FOR DETECTING COIL ALIGNMENT ERROR IN WIRELESS INDUCTIVE POWER TRANSMISSION", serial number 14/910,071), or using a predictive model based on speed, deceleration, and vehicle stopping characteristics (eg braking speed, vehicle weight). .

9A shows a converging wired dipole antenna 902 having at one end a GA 901 hosting a beacon signal source. Centerline 904 of GA 901 depicts the y-axis point at which the vehicle's VA (Vehicle Assembly) resonant inductive coil center should be located for maximum wireless power transfer efficiency. Antenna 902 extends in the opposite direction of the approach to the limit of ½ of a wavelength (or ¼ of a wavelength if implemented as a half-wave antenna). Separated end 903 of parallel right antenna element 907 and left antenna element 908 serves as a signal acquisition threshold 906 , where both vehicle-based receiver antennas 22 , 24 are at an approaching vehicle angle. Regardless, the transmitted beacon signal can be reliably detected. The GA-to-antenna threshold 905 is the point at which the signal transmitted by the wired dipole antenna 902 represents the end of the antenna 902 .

When using the converging wired dipole antenna 902 for vehicle alignment, the vehicle, whether human-driven or automatic, enters a charger-mounted parking compartment moving towards the GA 901 . Vehicle-mounted receiver antennas 22 , 24 will detect the signal transmitted from converging wired dipole antenna 902 at signal acquisition threshold 906 . The transmitted signal will be received at the right receiver antenna 24 and the left receiver antenna 22 .

FIG. 9B shows a graphical representation of the signal error function of the converging wired dipole antenna 902 illustrated in FIG. 9A . The X-axis 911 shows the range while the Y-axis 912 shows the relative beacon signal phase difference 913 between the receiver antennas 22 , 24 . As the vehicle moves over the end 903 of the wired antenna 902 , both receiver antennas 22 , 24 begin to receive a beacon signal. First, the signal acquisition, detection, amplitude relative amplitude will indicate an error in Y positioning (a zero in relative signal strength indicates correct Y positioning), whereas the received phase is determined by the right receiver antenna 24 and the left The initial signal acquisition at the receiver antenna 22 will be 180° out-of-phase (note that if a quarter wave antenna is used, the phase difference will be 90°). As the vehicle moves forward, the right antenna 24 and left antenna 22 pass through the end 903 of the antenna 902 (moving towards the GA 901), the right receiver antenna 24 and The phase difference 913 of the signal received by the left receiver antenna 22 begins to decrease as the vehicle approaches the GA 901 . The amplitude relative values of the signals received at the right receiver antenna 24 and the left receiver antenna 22 are used to determine the Y-axis (side-to-side) axis tracking. X-axis and Y-axis indications are periodically transmitted to the driver, driver-assist, or fully automated driving system to control steering and braking.

As the vehicle continues toward GA 901 , the system continues to generate Y-axis alignment indications using the signal strengths at right receiver antenna 24 and left receiver antenna 22 , while right receiver 24 . ) and the decreasing difference in signal phase as received at the left receiver 22 provides an X-axis range-versus-GA indication. At a position where the phase difference is equal to 0°, the right-to-left difference signal strength is expected to decrease to zero. This event reached the edge of GA 901 and the final coil positioning was determined (eg, "METHOD OF AND APPARATUS FOR DETECTING COIL ALIGNMENT ERROR IN WIRELESS INDUCTIVE POWER TRANSMISSION," Serial No. 14, filed Feb. 4, 2016. /910,071 ) can be activated to cover the distance 910 from the GA edge 905 to the GA centerline 904 , or vehicle speed and deceleration at the antenna threshold 905 . The rate may be used to estimate when the vehicle should be at zero speed to be positioned above the GA centerline 904 taking into account vehicle characteristics such as braking rate and vehicle weight.

10A shows a long (long antenna may be shorter or longer than full wavelength depending on placement) leaky transmission line 1007 to provide initial guidance, and wireless charging of GA 1003 from antenna end 1006 . Two ½ wave 'converging antennas' 1004, 1005 for distance measurement and alignment to the pad (note that the folded antenna system described in FIG. 6 can be used to provide equivalent service) It shows a vehicle alignment system for wireless power transmission location determination using a datum. All three antenna elements 1004 , 1005 , and 1007 start at GA 1003 .

In the example of FIG. 10A , the beacon signal is pulsed on long leakage line 1007 , and all antenna lines 1004 , 1005 , and 1007 have the same ISM spectrum (eg, one of 13.56 MHz, 27.12 MHz, 40.68 MHz). ), so it is transmitted continuously on sections of the converging antennas 1004 and 1005 to allow discrimination. The beacon signal used in the long leakage line antenna 1007 and the converging antenna segments 1004, 1005 may be in-phase or out of phase, because the This is because the distinction is based on signal modulation (eg ASK, pulsing).

FIG. 10B shows a graphical representation of a signal error function of the vehicle alignment system illustrated in FIG. 10A . The X-axis 1011 shows the range while the Y-axis 1012 shows the relative beacon signal phase difference 1009 between the receiver antennas 22 , 24 . As the vehicle moves beyond the end of the wired antenna 1007 , both receiver antennas 22 , 24 begin to receive a beacon signal at the end of range 1016 .

As the vehicle approaches the long leakage line 1007 , signal detection through either or both of the receiver antennas 22 , 24 is performed to provide a Y-axis (side-to-side) error indication 1010 . Allows for initial guidance using amplitude and phase difference. When the vehicle assembly mounted antennas 22 , 24 detect a continuous beacon signal from the converging antenna structure 1004 , 1005 indicating that the receiver antennas 22 , 24 have passed the converging antenna structure threshold 1006 , leakage A cutover from using line 1007 to converging antennas 1004 , 1005 will be performed. As shown in Figure 10b, this transition occurs when the received beacon signal changes and the relative received signal phase difference 1009 goes out of phase by 180°, from the received phase 1008 to (3 transmitted signals co-channel interference). This causes a sharp change (after region 1017) which creates an ambiguous region where this signal distinction is obstructed. Once the signal source switching is achieved, vehicle alignment and ranging proceeds as detailed in FIG. 9B (or as in FIG. 8B if a folded antenna is used).

Once the vehicle receiver antennas approach the zero-phase difference threshold 1002 , the vehicle assembly-based transmitter may initiate communications with the ground assembly receiver(s). The final positioning method (or a predictive model based on velocity determined by distance measurements provided by the use of a converged antenna system) is the distance between the zero relative phase difference threshold 1002 and the centerline 1001 of the GA 1003 (1014) can be used for

This multi-antenna approach can also serve as a 'soft-fail' system where failure of an antenna structure or transmission facility will not preclude operation of others.

An optional short-range transmitter unit 1013 (eg, a radio frequency transmitter) may be included at the end of any leak line installation. The radio-frequency transmitter unit 1013 may include a transmitter, a processor, and memory, as well as a wired communication subsystem for receiving data via the leaky line cable 1007 , from or through the GA 1003 . can This transmitter unit 1013 provides its GPS location and charging station's capabilities (eg, provided power levels, available power types (AC/DC), supported connector types, available payment forms). (eg, virtual wallet support, supported online account(s), supported memberships, swipe cards, credit, debit, club cards)). The transmitter unit 1013 is also powered via the leak line 1012 using a DC offset to the leak line beacon signal(s).

During a charging session (ie, if the vehicle is positioned over the GA 1003 ), the transmitter unit 1013 may be turned off or may broadcast information to other passing vehicles (eg, the charger is in use). , time remaining in the charging session). Information may be updated from GA 1003 via leakage line 1007 using signal modulation (eg, pulsed, amplitude modulated).

In any of the described installations, a failed pre-charging session alignment is achieved by shifting the GA and when a range measurement that exceeds a threshold can be obtained (eg, any Y-axis (lateral- It may be reset by restarting the alignment process (when sufficient range is obtained for correction of large-side) errors.

While various implementations have been described above, it should be understood that they have been presented by way of example only and not limitation. For example, any of the elements associated with the systems and methods described above may utilize any of the desired functionality presented above. Accordingly, the breadth and scope of the preferred implementations should not be limited by any of the sample implementations described above.

Claims (20)

A vehicle alignment system for aligning a first wireless powered induction coil of a vehicle with a second wireless powered induction coil in a parking slot for wireless charging through the use of magnetic resonance induction, comprising:
a grounding assembly disposed in the parking slot, the grounding assembly housing the second wireless power induction coil; and
a transmission line connected to the ground assembly and disposed in the parking slot to leak a signal having an operating frequency detected by the vehicle to guide the vehicle to the second wireless power induction coil for charging - the transmission line comprises one of a continuous wired monopole antenna disposed in a folded pattern with respect to the ground assembly and a converging wired dipole antenna having first and second sections extending away from the ground assembly;
including,
The vehicle detects the signal having the operating frequency leaking from the transmission line using at least two in-vehicle antennas mounted on opposite sides of the transmission line when the vehicle is aligned in the parking slot, and processing respective signals detected by the at least two vehicle-mounted antennas to determine a relative signal phase and amplitude between the respective signals indicative of left-right alignment of the vehicle with respect to the transmission line; A system for determining a distance to the assembly. The system of claim 1 , wherein the transmission line is disposed along a centerline of the parking slot. The system of claim 1 , wherein the transmission line is parallel to the centerline of the parking slot but offset from the centerline of the parking slot. The system of claim 1 , wherein the transmission line is curved along a trajectory to guide the vehicle to the ground assembly in the parking slot. 2. The system of claim 1, wherein the operating frequency is one of 40.68 MHz and 13.56 MHz. 2. The continuous wired monopole antenna of claim 1, wherein the transmission line comprises the continuous wired monopole antenna disposed in a folded pattern with respect to the ground assembly, a first end of the continuous wired monopole antenna connected to the ground assembly and the ground assembly of the ground assembly. offset on a first side of a centerline, and wherein a second end of the continuous wired monopole antenna is adjacent the grounding assembly on a second side of the centerline of the grounding assembly. 7. The system of claim 6, wherein the continuous wired monopole antenna includes first and second sections extending substantially parallel on the first and second sides of a centerline of the ground assembly. 2. The apparatus of claim 1, wherein the transmission line comprises the converging wired dipole antenna having the first and second sections extending away from the ground assembly, the first and second sections being parallel to each other and of the ground assembly. offset on respective sides of a centerline, wherein first ends of the first and second sections are connected to the grounding assembly. The system of claim 1 , wherein the ground assembly includes a wireless charger including one or more wireless charging coils and a magnetic inductive resonance communication transceiver, and a beacon signal source for transmitting a beacon signal over the transmission line. The system of claim 1 , further comprising a leaky transmission line coupled to the grounding assembly and extending away from the grounding assembly beyond an end of the transmission line remote from the grounding assembly. 11. The wireless charger of claim 10, wherein the grounding assembly comprises: a wireless charger comprising one or more wireless charging coils and a magnetic inductive resonance communication transceiver; and pulsing a beacon signal on the leaky transmission line; a beacon signal source providing a continuous beacon signal on the transmission line comprising one of a converging wired dipole antenna having first and second sections extending away from the ground assembly and a continuous wired monopole antenna disposed as system. 11. The method of claim 10, further comprising a transmitter at an end of the leaky transmission line remote from the grounding assembly, the transmitter receiving data from the grounding assembly via the leaky transmission line and receiving the data from the grounding assembly. A system that broadcasts at least a portion of the data. 13. The method of claim 12, wherein the data broadcast by the transmitter at the end of the leaky transmission line comprises: power levels provided by the ground assembly, power types available in the ground assembly (AC/DC). , the connector types supported by the grounding assembly, the payment forms accepted by the grounding assembly, whether the wireless charger of the grounding assembly is in use, and the amount of time remaining in a charging session being performed by the grounding assembly. A system comprising one. A method for aligning a first wireless powered induction coil of a vehicle with a second wireless powered induction coil in a parking slot for wireless charging through the use of magnetic resonance induction, comprising:
providing, by a grounding assembly disposed in the parking slot, a beacon signal to a transmission line disposed in the parking slot, to guide the vehicle to the second wireless power induction coil for charging;
the transmission line leaking the beacon signal at an operating frequency, the transmission line comprising a continuous wired monopole antenna disposed in a folded pattern with respect to the ground assembly, and first and second sections extending away from the ground assembly comprising one of the converging wired dipole antennas with
aligning the left-right of the vehicle in the parking slot with respect to the transmission line for charging by the second wireless power induction coil, wherein the aligning comprises: when the vehicle is aligned in the parking slot, the detecting the beacon signal at the operating frequency at which at least two vehicle-mounted antennas mounted on opposite sides of a transmission line leak from the transmission line; and
based on the distance to the ground assembly and the relative signal phase and amplitude between respective signals representing left-right alignment of the vehicle with respect to the transmission line, the alignment of the vehicle with respect to the second wireless power induction coil is determined. Steps to adjust
A method comprising 15. The method of claim 14, wherein the transmission line includes the continuous wired monopole antenna disposed in a folded pattern with respect to the ground assembly, connecting a first end of the continuous wired monopole antenna to the ground assembly and connecting the ground assembly to the ground assembly. offsetting the first end on a first side of a centerline, extending first and second sections of the continuous wired monopole antenna substantially parallel on a first side and on a second side of a centerline of the ground assembly; and placing a second end of the continuous wired monopole antenna adjacent the ground assembly on a second side of a centerline of the ground assembly. 15. The method of claim 14, wherein the transmission line includes the converging wired dipole antenna having the first and second sections extending away from the ground assembly, wherein the transmission line is offset on respective sides of a centerline of the ground assembly. The method further comprising the steps of arranging first and second sections parallel to each other and connecting first ends of the first and second sections to the ground assembly. 15. The method of claim 14, further comprising connecting the leaky transmission line to the ground assembly such that the leaky transmission line extends away from the ground assembly beyond an end of the transmission line remote from the ground assembly. 18. The method of claim 17, further comprising: the ground assembly pulsing a beacon signal on the leaky transmission line; and a continuous wired monopole antenna disposed in a folded pattern with respect to the ground assembly and first and and providing a continuous beacon signal on the transmission line comprising one of a converging wired dipole antenna having second sections. 18. The method of claim 17, further comprising: providing a transmitter at an end of the leaky transmission line remote from the ground assembly; the transmitter receiving data from the ground assembly via the leaky transmission line; and broadcasting at least a portion of the data received from an assembly. 20. The method of claim 19, wherein the step of the transmitter broadcasting data comprises: power levels provided by the ground assembly, power types available in the ground assembly (AC/DC), supported by the ground assembly. Broadcast data comprising at least one of connector types, payment forms accepted by the grounding assembly, whether a wireless charger of the grounding assembly is in use, and time remaining in a charging session being performed by the grounding assembly. A method comprising the step of casting.

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