Vehicle and method of operating advanced driver assistance system

Abstract

The invention relates to a vehicle and a method of operating an advanced driver assistance system. Illustrative vehicles, systems, and methods enable an ultrasonic sensing array to be adapted for near field communication with, for example, smart devices, parking infrastructure, and other vehicles. As one example, an exemplary vehicle includes: one or more ultrasonic sensors, the one or more ultrasonic sensors configured for proximity sensing; and a controller configured to receive an acoustic signal from the smart device using the one or more ultrasonic sensors. As another example, an exemplary vehicle includes: one or more microphones configured for at least one of noise cancellation, voice control, emergency vehicle detection, and proximity sensing; and a controller configured to receive an acoustic signal from the smart device using the one or more microphones, the acoustic signal being within a frequency range between 18 kHz and 25 kHz, including within 18 kHz and 25 kHz.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of provisional U.S. application 63 / 585,118, entitled “Ultrasonic Proximity Sensor,” filed on September 25, 2023 by named inventor Marek Hustava. The entire contents of the above application are hereby incorporated herein by reference. Technical Field

[0003] The present description relates to vehicles and methods of operating advanced driver assistance systems (ADAS). Background Art

[0004] Modern cars are equipped with a large number of sensors of various types. For example, cars are now commonly equipped with arrays of ultrasonic sensors to monitor the distance between the car and any nearby people, pets, vehicles or obstacles. Manufacturers continue to create and develop new selling features for their vehicles, which often require the addition of new sensor types and arrangements to support these new features. The commercial viability of these new selling features may depend on the cost and feasibility of integrating the new sensor system with the existing infrastructure of the vehicle. If the new selling features can utilize the existing infrastructure to achieve additional uses, they may be more desirable. Summary of the invention

[0005] Thus, exemplary vehicles, systems, and methods are disclosed herein that adapt ultrasonic sensing arrays to communicate with, for example, smart devices, parking infrastructure, and other vehicles in close proximity. As an example, an exemplary vehicle includes: one or more ultrasonic sensors configured for proximity sensing; and a controller configured to receive acoustic signals from a smart device using the one or more ultrasonic sensors.

[0006] As another example, an illustrative vehicle includes: one or more microphones configured for at least one of noise cancellation, voice control, emergency vehicle detection, and proximity sensing; and a controller configured to use the one or more microphones to receive an acoustic signal from a smart device, the acoustic signal being in a frequency range between 18 kHz and 25 kHz, inclusive.

[0007] As yet another example, an illustrative method of operating an advanced driver assistance system (ADAS) includes: performing ultrasonic proximity measurement using a first frequency range via an ultrasonic proximity sensor of the ADAS; and communicating with a smart device using a second frequency range lower than the first frequency range via the ultrasonic proximity sensor.

[0008] As yet another example, an illustrative vehicle includes one or more ultrasonic sensors configured for proximity sensing and a controller configured to transmit data to a second vehicle or an ultrasonic occupancy sensor using the one or more ultrasonic sensors.

[0009] Each of the above examples may be used alone or in combination, and may include one or more of the following features in any suitable combination: 1. The acoustic signal includes at least one of the following: a lock command, an unlock command, and an alarm command. 2. The acoustic signal is in a frequency range between 18 kHz and 25 kHz, including 18 kHz and 25 kHz. 3. The acoustic signal is in a frequency range between 20 kHz and 23 kHz, including 20 kHz and 23 kHz. 4. Each of the one or more ultrasonic sensors includes a MEMS (micro-electromechanical system) microphone. 5. The smart device is a smart phone. 6. The controller is also configured to use the one or more ultrasonic sensors to transmit a second acoustic signal to the smart device, and the acoustic signal and the second acoustic signal provide a two-way communication channel between the vehicle and the smart device. 7. The controller is also configured to use multiple ultrasonic sensors of the one or more ultrasonic sensors to direct the emitted acoustic signal to the smart device. 8. One or more ultrasonic transducers are used to transmit a second acoustic signal to the smart device, the acoustic signal and the second acoustic signal providing a two-way communication channel between the vehicle and the smart device. 9. The second frequency range is within a frequency band between 20 kHz and 23 kHz, including 20 kHz and 23 kHz. 10. The controller is also configured to use the one or more ultrasonic transducers to receive data from the second vehicle or the ultrasonic occupancy sensor. 11. The controller is also configured to use a plurality of the one or more ultrasonic transducers to direct a signal conveying the transmitted data to the second vehicle or the ultrasonic occupancy sensor. 12. The transmitted data includes vehicle registration information. 13. The transmitted data includes the identity of the owner or driver of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a view of a user approaching an exemplary vehicle.

[0011] Figure 2 is a block diagram of an exemplary driving / parking assistance system.

[0012] Figure 3 is a circuit schematic of an exemplary ultrasonic proximity sensor.

[0013] Figure 4 is a block diagram of an exemplary bidirectional communication channel.

[0014] Figure 5 is a flow chart of an exemplary short-range communication method that may be implemented by a smart device.

[0015] Figure 6 is a flow chart of an exemplary short-range communication method that may be implemented by a vehicle. DETAILED DESCRIPTION

[0016] The drawings and the following description do not limit the present disclosure, but rather, they provide a basis for those skilled in the art to understand all modifications, equivalents, and alternatives that fall within the scope of the claim language. Communications between vehicles and smart devices are used to provide an explanatory context, but the principles can be applied to vehicles communicating with infrastructure and other vehicles.

[0017] As an illustrative context of use, Figure 1 A user 102 is shown approaching a vehicle 104. When the user 102 comes into close range (e.g., within two to three meters), they possess a smart device 106. The smart device 106 may be a smart phone, smart watch, smart speaker, smart pendant, or any portable or wearable electronic device having a speaker and programmable functionality, such as may be provided in the form of a downloadable software application. It is contemplated that the smart device will have wireless connectivity via, for example, Wi-Fi, a cell service network, or via satellite to facilitate downloading software and / or long-range wireless communications to connect with one or more suitable Internet-accessible servers, but wireless connectivity is not required.

[0018] The smart device 106 is preferably a personal item that the user 102 already possesses and habitually keeps on their person or in their vicinity. Many suitable smart devices (e.g., smart phones) that are commercially available and widely used produce sound or music from digital data streams with sampling rates of 44.1kHz or 48kHz. Although these sampling rates are the most common and will be employed in the following discussion, other sampling rates are also in use and can be employed.

[0019] Although the hearing range of the average person decreases over time, the range of audible sound frequencies is generally taken as 20 Hz to 20 kHz. Sensitivity decreases at the edge of this range, so that near-ultrasonic frequencies (e.g., 18 kHz to 20 kHz) may be detectable, but unnoticeable to most people. A device using a 44.1 kHz sampling rate can produce ultrasonic frequencies up to 22.05 kHz, while a device using a 48 kHz sampling range can produce ultrasonic frequencies up to 24 kHz. The present disclosure contemplates the use of smart devices to generate acoustic signals in the range of 18 kHz to 25 kHz, or more preferably in the range of 20 kHz to 23 kHz, or even more preferably in the range of 21 kHz to 22 kHz.

[0020] Using a suitable software application, the smart device 106 can be configured to generate an ultrasonic signal or a near-ultrasonic signal to communicate with the vehicle 104. The generated acoustic signal can modulate the carrier frequency using amplitude modulation, phase modulation, frequency modulation, or a combination thereof (e.g., orthogonal amplitude modulation, frequency hopping, multi-carrier modulation). The generated acoustic signal can additionally or alternatively use up-chirps and down-chirs to represent channel symbols. The generated acoustic signal can use a message frame syntax, starting each frame with a preamble to enable timing synchronization and channel training at the receiver. The frame may include a predefined header, a message payload, and a checksum. Error correction decoding can be used to introduce controlled redundancy in the frame content. Scrambling masks can be applied to the message header and payload for encryption and "whitening" of the channel spectrum.

[0021] In any case, the generated acoustic signal may include, for example, a selectable one of a lock command, an unlock command, and an audible alarm command, thereby enabling the smart device 106 to act as a replacement for a traditional car key. This arrangement provides various potential advantages as further described below.

[0022] As is becoming commonplace for modern vehicles, the exemplary vehicle 104 is equipped with an array of ultrasonic proximity sensors 108. Such sensors typically employ pulse-echo techniques to measure the distance to nearby obstacles around the vehicle. The sensor 108 may include a piezoelectric transducer for periodically generating an ultrasonic pulse train. Although these piezoelectric transducers may also detect the reflection of the acoustic pulse train from nearby obstacles, recent sensor designs employ one or more MEMS (micro-electromechanical systems) microphones to detect the reflection. The ultrasonic proximity sensor 108 may be expected to operate in a frequency range of 40kHz to 60kHz, but we note here that MEMS microphones may be expected to operate well in the low audible range (to 10kHz or below), and may even exhibit peak sensitivity in the range of 22kHz to 34kHz. Therefore, no hardware modifications are required to make the exemplary vehicle 104 sensitive to acoustic signals in the range of 18kHz to 25kHz. The vehicle may be configured for close-range ultrasonic communication with firmware modifications to the sensor 108 and / or firmware modifications to the vehicle's ECU (electronic control unit).

[0023] The communication can be (but need not be) unidirectional. Although it is expected to be tuned for operation in the range of 40kHz to 60kHz and to exhibit reduced performance outside this range, the piezoelectric transducer can still be used to generate close-range acoustic signals in the range of 18kHz to 25kHz without significant hardware modifications. In some envisioned implementations, the vehicle 104 may employ an array of ultrasonic proximity sensors 108 to triangulate the position of the user 102, and then multiple transducers may be driven in a phased manner to provide directional gain of the acoustic signal to the smart device 106 (i.e., "direct" the acoustic signal to the smart device). Many suitable smart devices 106 include microphones with a sampling rate of 44.1kHz or 48kHz, enabling the smart device to receive ultrasonic or near-ultrasonic signals from the vehicle 104. Preliminary tests conducted with a spacing of about 2 meters between the device 106 and the sensor 108 indicate that a baud rate of 500 symbols per second to about 600 symbols per second is easily achievable in each direction.

[0024] Figure 2 A set of interconnected ECUs (electronic control units) 201 to 203 are shown organized in a hierarchical bus topology. Of course, other topologies, including serial, parallel, star, and ring topologies, are also suitable and are contemplated for use in accordance with the principles disclosed herein. Although multiple ECUs are shown and described herein, in some cases it may be preferable to utilize a single ECU to implement various functions.

[0025] The first ECU 201 is coupled to an array of ultrasonic proximity sensors 108, each of which may include a ULS transducer and a MEMS microphone. The first ECU 201 may also be coupled to the following items: additional ultrasonic transducers 208, which are used for additional area coverage and / or acoustic signal gain; additional microphones 206, which are used for example for noise cancellation, siren detection, voice control; and radio frequency interfaces 204, which are used for example for cellular network connection, satellite navigation, wireless services.

[0026] To provide automatic parking or other advanced features, the second ECU 202 may be connected to a set of actuators, such as a door lock actuator 210, a throttle actuator 212, a brake actuator 214, a steering actuator 216, and a turn signal actuator 218. The third ECU 403 may be coupled to a user interactive interface 220 to accept user input and provide a display of various measurements and system status. Using this interface, sensors, and actuators, the ECUs 201 to 203 may provide automatic parking, assisted parking, lane change assistance, obstacle and blind spot detection, and other desired features.

[0027] Figure 2 Also shown is a smart device 106 that communicates with an ultrasonic proximity sensor 108, sending and / or receiving ultrasonic or near-ultrasonic acoustic signals. The sensor 108, operating alone or in combination with the ECU 201, can interpret messages received from the smart device to initiate actions such as locking or unlocking a door.

[0028] Figure 3 1 shows a block diagram of an exemplary controller 302 for the sensor 108. The controller 302 employs IO (input and output) pins that are multiplexed to a selected one of various IO protocol modules. The modules are shown for I 2 C (Inter-Integrated Circuit), SPI (Serial Peripheral Interface), and DSI3 (Third Generation Distributed System Interface) communication bus protocols are contemplated, but these are merely non-limiting examples. Other contemplated protocols include those set forth in the LIN, CAN, and SENT standards. The IO bus 310 couples the various IO protocol modules to the embedded microprocessor (μP). An AMBA (Advanced Microcontroller Bus Architecture) bus (such as, for example, AHB-Lite (Simplified Advanced High-Performance Bus)) can be used to couple the embedded microprocessor to various other functional blocks of the sensor controller 302. Such blocks may include, for example, non-volatile firmware (FW) memory, volatile working memory (MEM), a digital signal processor (DSP), a power-on reset (POR) module, a microphone signal receiver (RX M) ADC (Analog-to-Digital Converter), for transducer signal receiver (RX T ) of the second ADC, driving the current transmitter (TX I ) and the drive voltage transmitter (TX V ). (The transmitters generate the drive signal for the ultrasonic transducer as a controlled current or a controlled voltage, respectively.) The multiplexer may couple a selected one of the transmitters to an output pin for driving the piezoelectric transducer 304. Figure 3 Further shown is an embedded oscillator (OSC) that generates one or more clock signals for various other blocks, optionally including carrier frequencies for transmitters and receivers. The POR module can control the distribution of clock signals to enable sleep modes for unneeded components and other power saving features.

[0029] The IO pins couple the sensor controller 302 to an ECU (electronic control unit) directly or indirectly (e.g., via a DSI3 bus master). The ECU can transmit commands to the various sensor controllers to, for example, set values ​​for various configuration parameters of the sensor, initiate the transmission of an acoustic burst, and collect signal data or other measurements. The microprocessor in each sensor controller 302 operates according to firmware and stored configuration parameters to interpret commands from the ECU and perform appropriate operations, including the transmission of acoustic bursts and the reception of acoustic signals.

[0030] In various embodiments, a chirp modulated signal is used, such as a linear frequency modulation ("LFM") chirp. A chirp is a pulse that changes frequency during transmission. An up-chirp is a single pulse whose frequency increases during transmission, and a down-chirp is a single pulse whose frequency decreases during transmission. For clarity, the examples used herein will consider a linear increase or decrease, however, in various embodiments, the increase or decrease is not linear. The chirped echo can be compressed in the correlator without introducing a large amount or any correlated noise. Therefore, peak detection of the echo is facilitated without reducing the time resolution. In addition, the LFM chirp can withstand Doppler shift without the presence of correlated noise increase or with minimal any correlated noise increase. The LFM chirp can be used as a transmit pulse for measuring the distance to an obstacle or object within the sensing range of the sensor system.

[0031] In other specific implementations, an AM (amplitude modulation) signal is used, such as a shaped pulse of a fixed frequency carrier. The AM signaling mode can enable the use of shorter pulse trains (e.g., about 200 microseconds to 300 microseconds), thereby reducing the transmission time and increasing the sensitivity to nearby obstacles. Other specific implementations may use pulses with a modulated carrier (e.g., using binary phase shift keying (BPSK) modulation). For the sake of clarity, the term "burst" as used herein refers to an AM (fixed frequency), BPSK (modulation) or chirped (sweep frequency) pulse, which can be a pulse train in a series of pulse trains generated by driving a piezoelectric element or other ultrasonic transducer. The chirped modulated pulse may have a longer duration than a typical AM pulse, for example greater than 1 millisecond, such as in the range of 2 milliseconds to 3 milliseconds. It is noted here that the pulse train length can be changed, with shorter pulse trains used to facilitate the detection of nearby obstacles and longer pulse trains used to increase the pulse train energy (and echo energy) of obstacles farther away. The pulse train length for detecting nearby obstacles may be half or possibly one quarter of the pulse train length for obstacles further away.The sensor may be switched between modes for different detection distances.

[0032] Although systematically varying the characteristic frequency (e.g., the starting frequency, or equivalently the center or ending frequency) of the chirped modulated pulses in the sequence is considered particularly useful, such frequency variation can also be applied to the carrier frequency of the AM pulses in the sequence. The frequency variation of each pulse can be expressed as a frequency displacement from a nominal characteristic frequency (e.g., a nominal starting frequency or a nominal carrier frequency).

[0033] To transmit a train of acoustic pulses, the microprocessor instructs the selected transmitter to drive an output pin for an ultrasonic transducer, which is coupled to a piezoelectric element PZ. A transformer and / or a resonant tuning network may be provided to amplify the voltage and control the resonant frequency of the transducer. The transmitter may receive a carrier frequency signal having a nominal frequency of, for example, 50 kHz from an oscillator. The transmitter may use the carrier frequency signal to generate a series of AM (amplitude modulation) or chirped pulses, each pulse corresponding to a train of acoustic pulses. An example of a chirped pulse may be a pulse in which the frequency is swept upward from 7 kHz below the carrier frequency to 7 kHz above the carrier frequency (up chirp). Alternatively, a down chirp may be employed in which the frequency is swept linearly downward rather than upward. In some contemplated implementations, the transmitter provides a customized frequency offset pattern to the train of acoustic pulses to serve as a unique signature of the ultrasonic transducer.

[0034] To receive the acoustic signal, the microprocessor instructs one or two ADCs to digitize the electrical receive signal 307 from the MEMS microphone 306 and / or the receive signal 308 from the piezoelectric element 304. The digitized signal can be provided directly to the DSP for real-time processing, or buffered in a memory for subsequent processing by the DSP or ECU. To reduce IO bandwidth requirements, the DSP can implement data compression to reduce the number of bits required to represent the ZIF IQ data or to represent the magnitude of the baseband signal. To further reduce bandwidth requirements, the DSP can perform on-chip processing for peak detection and distance estimation. Various suitable processing techniques for detecting reflections of acoustic pulse trains are known in the art, including co-owned U.S. Patent Publication 2024 / 0069192 "Motion-compensated distance sensing with concurrent up-chirp down-chirp waveforms", which is hereby incorporated by reference into this document.

[0035] Since the received electrical signal is usually in the millivolt or microvolt range, the receiver RX M RX T An amplifier may be included to buffer and amplify the signal from the receive terminal. An analog or digital mixer may be included to down-convert the received signal to baseband for further filtering and processing by the DSP. In one specific implementation, the mixer is an in-phase / quadrature (I / Q) digital mixer that gives zero intermediate frequency (ZIF) IQ data as its output. (Although the term "ZIF" is used herein, the down-converted signal may be a low intermediate frequency or "near baseband" signal in practice.)

[0036] The DSP applies programmable methods to acquire the received signal and detect any echoes and measure their parameters, such as time of flight (ToF), duration, and peak amplitude. Such methods may employ threshold comparison, minimum interval, peak detection, zero crossing detection and counting, noise level determination, and other customizable techniques customized to improve reliability and accuracy. It is worth noting that the peak detection process itself has variants, some of which perform rising edge detection, falling edge detection, or peak maximum detection. The processing of nearby obstacle detection may be performed entirely in the controller 302, or may be shared with or delegated to an ECU or host processor, which receives certain data via a communication bus, as previously described.

[0037] In addition to the proximity sensing operations described above, the sensor controller 302 may also monitor received signals 307 for communications from the smart device 106. Such monitoring may be continuous, or may be interrupted during proximity sensing operations. Alternatively, such monitoring may be performed a predetermined time after a triggering event, such as, for example, detection of motion near the vehicle, actuation of a door handle, detection of a bump or minor vibration of the vehicle. Such monitoring may be performed using a sensor such as Figure 4 The arrangement shown is arranged to perform monitoring.

[0038] The amplified received signal from the receiver RX is digitized by the analog-to-digital converter ADC. The DSP obtains the digitized received signal from the ADC or from a buffer in the memory MEM. The DSP may implement the various modules according to instructions retrieved from the firmware memory FW, or the modules may be implemented as application specific integrated circuits. (Alternatively, the modules may be implemented by a field programmable gate array (FPGA) or other form of programmable logic device (PLD)). The first module may process the digitized received signal by digitally comparing the digitized received signal to a carrier frequency signal f C The digitized received signal is mixed and low-pass filtered to down-convert the digitized received signal. In one specific implementation, this module is an in-phase / quadrature (I / Q) digital mixer that gives zero intermediate frequency (ZIF) IQ data as its output. (Although the term "ZIF" is used herein, the down-converted signal may be a low intermediate frequency or "near baseband" signal in practice.)

[0039] The second module may be a correlation filter (CORR) with an impulse response corresponding to a time-reversed preamble or synchronization word pattern specified by the communication protocol of the smart device. Such a filter generates a peak when a preamble or synchronization word pattern is received. When the correlation filter output exceeds a predetermined threshold, the DSP may enable subsequent modules for symbol detection and clock recovery. The symbol detection and clock recovery module may perform channel equalization to obtain an equalized signal. Symbol detection may be performed by comparing the equalized signal amplitude, phase, frequency, frequency derivative, etc. with various decision thresholds. Symbol clock recovery may be performed by comparing the equalized signal characteristics with the target value of the symbol decision. The symbol decision sequence may be provided to an extraction module (EXTR), which extracts command and other message parameter values ​​from each message frame together with optional descrambling, decoding, and error correction. The DSP may implement a state machine (SM) or other mechanism to process the received commands and parameter values. In the case of desired two-way communication, the state machine module may determine an appropriate response or confirmation message and may provide it to the transmitter (TX). The transmitter drives an ultrasonic transducer (PZ) to send a response or confirmation message as an ultrasonic signal or a near-ultrasonic signal to the smart device. As mentioned previously, communication with the smart device may occur in a much lower frequency range than that used for proximity sensing.

[0040] Figure 5 is a flow chart of an exemplary short-range communication method that can be implemented by smart device 106. In block 502, the device determines whether a connection should be attempted. The trigger for the connection attempt can be, for example, receiving an acoustic beacon signal from the vehicle, determining by a navigation system or location tracking system that the user has returned to the vicinity of the vehicle, opening or waking up an application on the device, physically tapping or shaking the device, or a voice command from the user. The device continues in block 502 until a trigger is detected. Once a trigger is detected, the device generates an acoustic signal containing a connection request in block 504.

[0041] In block 506, the device checks for an acoustic signal containing a response message. If a valid response message is not detected within a predetermined time window, the device checks in block 508 whether a connection attempt timer has elapsed. If so, the process returns to block 502 to wait for another trigger. Otherwise, another connection request message is sent in block 504. Once a valid response message is received in block 506, the device proceeds to block 510.

[0042] In box 510, the device may select a command to be sent to the vehicle in box 512. In box 512, the device sends the command as an acoustic signal. In box 514, the device checks the acoustic signal for a response message. If a valid response message is not detected within a predetermined time window, the device checks in box 516 whether the command timer has elapsed. If so, the process returns to box 502 to wait for another trigger. Otherwise, the command message is retransmitted in box 512. Once a valid response message is received in box 514, the device proceeds to box 518 to determine whether more commands will be sent. If so, the device returns to box 510. Otherwise, the device returns to box 502.

[0043] The command sequence may vary, but may include, for example, an unlock command, an engine start command, a climate control on command, an audio system on command, and a seat reposition command. Isolated commands are also contemplated, such as a side door open command, a trunk open command, a hood disengage command, an audio alarm command, or a lock command. In the case of support by a driver assistance system, the commands may include a self-parking command or an automated valet parking command.

[0044] Figure 6 602 is a flow chart of an exemplary short-range communication method that can be implemented by a vehicle or more specifically by one or more of the sensor controllers and / or by an ECU. In box 602, the vehicle determines whether a connection should be attempted. The trigger for the connection attempt can be, for example, detection of nearby motion, detection of footsteps or other sounds, actuation of a door handle (or hood disengagement, trunk latch or fuel filler door), detection of a physical impact (or kick or vibration) of the vehicle, detection of a voice command, or detection of a connection request. The vehicle continues in box 602 until a trigger is detected. Once a trigger is detected, the vehicle generates an acoustic signal containing a beacon in box 604.

[0045] In block 606, the vehicle checks for an acoustic signal containing a connection request message. If a valid request message is not detected within a predetermined time window, the vehicle checks in block 608 whether a connection attempt timer has elapsed. If so, the process returns to block 602 to wait for another trigger. Otherwise, another beacon message is sent in block 604. Once a valid request message is received in block 606, the vehicle proceeds to block 610.

[0046] In block 610, the vehicle may send a response message to the device. The response message may include the results of a previously transmitted command or other information. For example, the response message may include vehicle status information, such as whether the vehicle is actively charging / refueling, charge / refueling level, interior temperature, tire pressure, odometer reading, service alerts. Other potential information includes vehicle owner or registration information, parking pass information, assigned valet parking ticket information. Such information may be provided by default or in response to an information request command.

[0047] After sending the response message in box 610, the vehicle may check for an acoustic signal containing another command message in box 612. If a valid command message is received, the vehicle may attempt to execute the command in box 614, after which the process moves to box 610 to transmit a response message confirming the command and transmitting the result (e.g., whether the command was successfully executed). If a valid command message is not detected within a predetermined time window, the vehicle checks in box 616 whether the command timer has elapsed. If so, the process returns to box 602 to wait for another trigger. Otherwise, the previous response message is retransmitted in box 610.

[0048] Potential advantages of the above arrangement include the ability to easily transfer or share authorized access to a vehicle without the need to deliver or duplicate a physical key. The likelihood of losing a key may be reduced particularly with regular backup using a smart device, and access from a stolen smart device may be easily revoked and transferred to a replacement device. The use of a smart device may enable features such as voice command-based access, alerts regarding left-behind vehicle occupants, and access to Internet-facilitated services including parking facilities, rental services, and the like.

[0049] The expected range of acoustic signals from typical smart devices is limited to less than, for example, 3 meters. Out-of-band operation of ultrasonic transducer responses may be similarly limited, or in some cases, range limits may be enforced using proximity sensing measurements or source triangulation to determine the user's location. Such close range limitations are expected to prove advantageous in terms of security against interception or so-called "man-in-the-middle" attacks.

[0050] The above discussion focuses on communication between smart devices and vehicles. We note here that the vehicle's array of ultrasonic proximity sensors can also communicate with other vehicles and with infrastructure sensors such as ultrasonic area / occupancy sensors used to detect when a vehicle occupies a parking space in a parking garage. Similar sensors are used to detect when a vehicle is in front of, for example, a gas station / charging station or an entry barrier / barrier exit barrier. Such communications may occur at the higher frequencies (e.g., 30kHz to 90kHz) that the infrastructure sensors are designed to operate, but in other respects the communication process may be similar to the communication process described previously.

[0051] Vehicle-to-infrastructure communications can facilitate parking services or refueling services by automating the exchange of information associated with such transactions. Other services can also be enabled, such as enabling large parking lots to quickly determine the location of a given vehicle. For autonomous vehicles, the infrastructure can relay commands to select vehicles to travel to a building entrance or some other selected location. For buildings or other infrastructure with existing sensor arrays, such services can be introduced at essentially no additional cost.

Claims

1. A vehicle, characterized in that: The vehicle comprises: one or more ultrasonic sensors configured for proximity sensing; and A controller is configured to detect a parking obstacle using the one or more ultrasonic sensors and is further configured to receive an acoustic signal from a smart device using the one or more ultrasonic sensors. 2 . The vehicle according to claim 1 , wherein the acoustic signal comprises at least one of the following: a lock command, an unlock command, and an alarm command.

3. The vehicle of claim 1, wherein the acoustic signal is within a frequency range between 18 kHz and 25 kHz, inclusive. 4 . The vehicle of claim 1 , wherein the acoustic signal is within a frequency range between 20 kHz and 23 kHz, inclusive. 5 . The vehicle of claim 1 , wherein each of the one or more ultrasonic sensors comprises a micro-electromechanical system (MEMS) microphone. The vehicle of claim 1 , wherein the smart device is a smart phone.

7. The vehicle of claim 1, wherein the controller is further configured to use the one or more ultrasonic sensors to transmit a second acoustic signal to the smart device, the acoustic signal and the second acoustic signal providing a two-way communication channel between the vehicle and the smart device.

8. The vehicle of claim 1, wherein the controller is further configured to use a plurality of the one or more ultrasonic sensors to direct the emitted acoustic signals to the smart device.

9. A vehicle, characterized in that: The vehicle comprises: one or more microphones configured for at least one of noise cancellation, voice control, emergency vehicle detection, and proximity sensing; and A controller is configured to receive an acoustic signal from a smart device using the one or more microphones, the acoustic signal being in a frequency range between 18 kHz and 25 kHz, inclusive.

10. The vehicle of claim 9, wherein the acoustic signal is within a frequency range between 20 kHz and 23 kHz, inclusive.

11. The vehicle of claim 9, wherein the acoustic signal comprises at least one of: a lock command, an unlock command, and an alarm command.

12. The vehicle of claim 9, wherein the vehicle further comprises one or more ultrasonic transducers, wherein the controller is further configured to use the one or more ultrasonic transducers to transmit a second acoustic signal to the smart device, the acoustic signal and the second acoustic signal providing a two-way communication channel between the vehicle and the smart device.

13. A method for operating an advanced driver assistance system (ADAS), characterized in that: The method comprises: performing ultrasonic proximity measurements via an ultrasonic proximity sensor of the ADAS using a first frequency range; and A second frequency range lower than the first frequency range is used to communicate with a smart device via the ultrasonic proximity sensor.

14. The method of claim 13, wherein the second frequency range is within a frequency band between 20 kHz and 23 kHz, inclusive.

15. The method of claim 13, wherein the communicating comprises receiving at least one of: a lock command, an unlock command, and an alarm command.

16. A vehicle, characterized in that: The vehicle comprises: one or more ultrasonic sensors configured for proximity sensing; and A controller is configured to transmit data to a second vehicle or an ultrasonic occupancy sensor using the one or more ultrasonic sensors.

17. The vehicle of claim 16, wherein the controller is further configured to use the one or more ultrasonic sensors to receive data from the second vehicle or the ultrasonic occupancy sensor.

18. The vehicle of claim 16, wherein the controller is further configured to use a plurality of the one or more ultrasonic sensors to direct a signal conveying the transmitted data to the second vehicle or ultrasonic occupancy sensor.

19. The vehicle of claim 16, wherein the transmitted data includes vehicle registration information.

20. The vehicle of claim 16, wherein the transmitted data includes the identity of an owner or driver of the vehicle.

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