An automatic driving early warning system and method based on acoustic wave communication

Abstract

This invention discloses an autonomous driving early warning system and method based on acoustic wave communication. The system includes a field acoustic beacon and an on-board acoustic early warning receiver. The field acoustic beacon responds to sudden events by broadcasting acoustic digital signals containing early warning information. The on-board acoustic early warning receiver captures and decodes the signals in real time and sends the early warning information to the vehicle's decision-making level for execution. The two communicate unidirectionally via sound waves in a preset dedicated emergency frequency band, with the communication path independent of cellular networks and roadside infrastructure. The field acoustic beacons are divided into mobile beacons and portable beacons, employing directional or omnidirectional transmission modes, respectively. The on-board receiver includes a microphone array, a beamforming unit, a signal processing and decoding module, and a decision fusion module. This invention utilizes the advantages of stable sound wave propagation, low latency, and lack of line-of-sight limitation to achieve real-time and reliable early warning of sudden dangerous events beyond line-of-sight, eliminating blind spots for autonomous vehicles and improving driving safety.

Description

Technical Field

[0001] This invention relates to the field of autonomous driving technology, and in particular to an autonomous driving early warning system and method based on acoustic wave communication. Background Technology

[0002] Current autonomous driving systems primarily rely on onboard sensors (cameras, LiDAR, millimeter-wave radar) and vehicle-to-everything (V2X) communication for environmental perception. However, when facing sudden and temporary dangerous events such as traffic accidents, road debris, or emergency vehicle passage, existing technologies have two significant drawbacks: First, optical and radar sensors are limited by line-of-sight propagation and cannot detect dangers behind curves, on the other side of hilltops, or in areas obscured by large obstacles, creating blind spots. Second, early warning systems based on cellular networks or direct communication follow a "perception-convergence-forwarding" paradigm, introducing significant network transmission and processing delays (on the order of seconds), and are highly dependent on network coverage and stability, making them unreliable for scenarios requiring immediate response.

[0003] Therefore, there is an urgent need for an over-the-horizon early warning technology that is not limited by line of sight, has low latency, and is independent of existing communication networks. Summary of the Invention

[0004] The purpose of this invention is to disclose an autonomous driving early warning system and method based on acoustic communication, which solves the technical problems of existing autonomous driving systems having blind spots in perception of sudden dangerous events beyond visual range, as well as high communication link delay and poor reliability.

[0005] To achieve the above objectives, this invention discloses an autonomous driving early warning system based on acoustic wave communication, comprising: At least one on-site acoustic beacon, set up at the scene of an emergency, is used to broadcast an acoustic digital signal containing early warning information in response to the triggering of the event; At least one vehicle-mounted acoustic warning receiver is installed in the autonomous vehicle to capture and decode the acoustic digital signals broadcast by the on-site acoustic beacon in real time, extract warning information and send it to the vehicle decision-making level for execution; The on-site acoustic beacon and the vehicle-mounted acoustic warning receiver communicate unidirectionally via sound waves on a preset dedicated emergency frequency band, with the communication path independent of the wireless cellular network and roadside infrastructure.

[0006] Specifically, the on-site acoustic beacon includes a mobile acoustic beacon integrated into a special vehicle, which includes: The trigger interface module is used to generate trigger signals in response to the emergency mission status of special vehicles; The control and encoding module is used to generate a data packet containing early warning information after receiving a trigger signal, and to perform channel coding and spread spectrum modulation on the data packet to generate an acoustic digital signal frame. A directional transmission module is used to broadcast the acoustic digital signal frame in a directional mode within a preset dedicated emergency frequency band.

[0007] Specifically, the directional transmission module of the mobile acoustic beacon consists of multiple ultrasonic transducer units, configured to broadcast based on the vehicle's current heading angle in the direction the vehicle is facing. When the vehicle is reversing, the directional beam still points in the direction the vehicle is facing. The mobile acoustic beacon also includes a status monitoring module, which is used to monitor the working status of the transmission module in real time and issue a prompt when there is an abnormality.

[0008] Specifically, the on-site acoustic beacon includes a portable acoustic beacon, which is manually placed by rescue personnel and includes: The switch module is used to control the beacon's activation and deactivation. The positioning module is used to obtain the real-time geographical coordinates of the beacon and detect its movement. The control and encoding module is used to generate a data packet containing warning information after receiving a broadcast start command, and to perform channel coding and spread spectrum modulation on the data packet to generate an acoustic digital signal frame. An omnidirectional transmission module is used to broadcast the acoustic digital signal frame in omnidirectional mode within a preset dedicated emergency frequency band; The power supply module is used to supply power to each module.

[0009] Specifically, the portable acoustic beacon also includes a collision detection module, which controls the beacon to enter a random backoff mode when other active beacons are detected nearby. The random backoff mode includes randomly selecting a delay time before sending the next frame, or using code division multiple access to assign different spreading codes to different beacons.

[0010] Specifically, the portable acoustic beacon also includes an auxiliary safety module, which includes a tilt sensor to detect whether the beacon is tilted and to automatically stop broadcasting and issue an alarm when the tilt angle exceeds a preset threshold.

[0011] Specifically, the vehicle-mounted acoustic warning receiver includes: The acoustic capture module consists of a microphone array composed of multiple MEMS microphone units, used to acquire acoustic signals from the vehicle's surrounding environment in real time, and integrates a beamforming unit to enhance signals from the direction of interest. The signal processing and decoding module is used to synchronously detect, demodulate, despread, and decode the captured acoustic signals to restore the early warning information data packets and parse the event type code and action command code. The decision fusion and execution module connects with the vehicle's original perception system and drive-by-wire chassis system to perform cross-validation based on the received warning information and map the validated instructions to the underlying control actions. The monitoring module is used to continuously monitor the dedicated emergency frequency band in a low-power mode during vehicle operation, and generate a wake-up signal to wake up the signal processing and decoding module when a valid preamble is detected.

[0012] Specifically, the decision fusion and execution module has a built-in priority arbitrator, which is used to trigger a preset security arbitration strategy when acoustic commands and perception data conflict. The priority arbitrator decides in the following order: a) event type priority; b) distance priority; c) signal strength priority; d) if it cannot be distinguished, "caution mode" is triggered.

[0013] On the other hand, in order to achieve the above objectives, this invention discloses an autonomous driving early warning method based on acoustic wave communication, comprising: Step a: Event Triggering and Beacon Activation. Based on the unexpected events that occur on-site, trigger and activate the acoustic beacons deployed on-site. Step b: Generate and encode warning information. The acoustic beacon generates a warning information data packet that matches the current event, and performs channel coding and spread spectrum modulation on the data packet to generate an acoustic digital signal frame. Step c: Start acoustic broadcasting. The acoustic beacon broadcasts the acoustic digital signal frame in a preset dedicated emergency frequency band through its acoustic wave transmitter. Step d: Acquisition and reception. The autonomous vehicle in motion acquires acoustic signals from the surrounding environment in real time through the onboard microphone array and performs beamforming processing on the acquired signals. Step e: Signal processing and command extraction, demodulating, despreading and channel decoding of the captured acoustic signal to restore the warning information data packet, and parsing to obtain the event type code and action command code; Step f: Decision fusion and execution. The parsed action command code is input into the decision planning module of the autonomous vehicle, cross-validated with the perception data of the on-board sensors, and the corresponding emergency behavior strategy is triggered based on the verification result.

[0014] Specifically, when multiple portable beacons broadcast simultaneously in a nearby area, a collision detection and backoff step is also included: during the broadcast interval, the beacon listens to a preset frequency band to detect whether there are broadcast signals from other beacons; if a collision risk is determined, a backoff strategy is executed, which includes random backoff, code division multiple access, or time division multiplexing.

[0015] The beneficial effects of this invention are as follows: By setting up on-site acoustic beacons independent of cellular networks, this invention broadcasts acoustic digital signals containing warning information at the scene of emergencies. The signals are then captured and decoded in real time by the vehicle-mounted acoustic warning receiver and directly input into the vehicle's decision-making layer for execution. By utilizing the physical characteristics of sound wave propagation being stable, unaffected by electromagnetic interference, requiring no spectrum authorization, and having extremely low broadcast latency, this invention achieves real-time and reliable warnings for dangerous events beyond visual range, significantly improving the safety and reliability of autonomous driving systems in complex road environments. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of the autonomous driving warning system of the present invention; Figure 2 This is a schematic diagram of the structure of the mobile acoustic beacon of the present invention; Figure 3 This is a schematic diagram of the structure of the portable acoustic beacon of the present invention; Figure 4 This is a schematic diagram of the structure of the vehicle-mounted acoustic warning receiver of the present invention; Figure 5 This is a flowchart illustrating the autonomous driving early warning method based on acoustic wave communication of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In this invention, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing the invention and its embodiments, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to be constructed and operated in a specific orientation.

[0020] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in certain situations to indicate a dependency or connection. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0021] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0022] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, components, or parts (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, components, or parts. Unless otherwise stated, "a plurality of" means two or more.

[0023] The technical solution of the present invention will be further described below with reference to the embodiments and accompanying drawings.

[0024] Example 1 like Figure 1 As shown, this embodiment provides an autonomous driving warning system based on acoustic communication, including at least one on-site acoustic beacon and at least one vehicle-mounted acoustic warning receiver; The on-site acoustic beacon is set up at the scene of the emergency and is used to broadcast an acoustic digital signal containing early warning information in response to the event; the vehicle-mounted acoustic early warning receiver is set up in the autonomous vehicle and is used to capture and decode the acoustic digital signal in real time, extract the early warning information and send it to the vehicle decision-making level for execution. The on-site acoustic beacon and the vehicle-mounted acoustic warning receiver communicate unidirectionally via sound waves in a preset dedicated emergency frequency band. The communication path is independent of the wireless cellular network and roadside infrastructure.

[0025] In this embodiment, the field acoustic beacon includes two types based on deployment method and mobility: mobile acoustic beacons and portable acoustic beacons.

[0026] (a) Mobile acoustic beacon The mobile acoustic beacon is integrated into a special vehicle, including ambulances, fire trucks, and police cars, and includes the following modules: a trigger interface module, a control and encoding module, and a directional transmission module, such as... Figure 2 As shown.

[0027] The trigger interface module is connected to the vehicle's original alarm system or warning light controller to automatically generate a trigger signal when the vehicle performs an emergency task and activates the alarm; or, the trigger interface module is a manual physical button located in the driver's cab for manual activation or forced deactivation.

[0028] The control and coding module is used to generate a warning information data packet that matches the current event when a trigger signal is received. The warning information data packet includes at least: an event type code, an action command code, and dynamically updated real-time vehicle location. The control and encoding module is further configured to perform channel coding and spread spectrum modulation on the data packet to generate an acoustic digital signal frame.

[0029] In this embodiment, the control and coding module employs Direct Sequence Spread Spectrum (DSSS) technology, with the carrier frequency set to 22.5kHz ± 2kHz. Channel coding uses convolutional coding (2,1,7) with a code rate of 1 / 2 and a generator polynomial of (171,133). Data packets are block-interleaved after encoding, with an interleaving depth of 14 rows × 16 columns to resist burst interference. The data structure of the acoustic digital signal frame includes: a 16-bit preamble synchronization code, fixed at 0xEB90; an 8-bit frame header for identifying the protocol version and priority; a 24-bit beacon ID; an 8-bit event type code; an 8-bit action command code; 32-bit longitude; 32-bit latitude; an 8-bit radius of influence; and a 16-bit CRC checksum.

[0030] The directional transmission module consists of multiple ultrasonic transducer units (e.g., an 8×4 array) configured to broadcast in a directional mode within a preset dedicated emergency frequency band, pointing towards the direction the vehicle is facing, based on the vehicle's current heading angle; when the vehicle is reversing, the directional beam still points towards the direction the vehicle is facing, rather than the reversing direction.

[0031] Optionally, the mobile acoustic beacon also includes a status monitoring module for real-time monitoring of the operating status of the transmitting module, including impedance and temperature, and for alerting the driver in case of anomalies.

[0032] (ii) Portable acoustic beacon The portable acoustic beacon is manually placed by rescue personnel at a safe location behind the scene of the emergency. The safe location is determined based on the road type, speed limit, and sound wave propagation attenuation model, and is preferably 150-300 meters away.

[0033] like Figure 3 As shown, the portable acoustic beacon includes the following modules: a switch module, a positioning module, a control and encoding module, an omnidirectional transmission module, and a power supply module.

[0034] Optionally, it may also include a conflict monitoring module and an auxiliary security module.

[0035] The switch module is a three-state knob or button used to control the acoustic beacon's power-on, standby, and broadcast startup.

[0036] The positioning module is used to obtain the real-time geographical coordinates of the beacon, including longitude and latitude, and to detect the movement status of the device. If the movement speed is greater than 0.5m / s, it is determined to be in motion, and the broadcast is restricted from starting.

[0037] The control and encoding module is used to generate a warning information data packet after receiving a broadcast start command. The warning information data packet includes at least: an event type code, an action command code, current geographical coordinates, and a preset influence radius. The control and encoding module is also used to perform channel coding and spread spectrum modulation on the data packet to generate an acoustic digital signal frame. Its coding and modulation method and data frame structure are the same as those of the mobile acoustic beacon.

[0038] The omnidirectional transmitting module uses a piezoelectric ceramic ring transducer to broadcast acoustic digital signal frames to the surrounding environment in a horizontal 360° omnidirectional radiation mode within a preset dedicated emergency frequency band.

[0039] The power module includes a rechargeable battery and a power management circuit to supply power to each module.

[0040] The auxiliary safety module includes a tilt sensor configured to detect whether the beacon is tilted and to automatically stop broadcasting and issue a buzzer alarm when the tilt angle exceeds 30°.

[0041] The collision detection module is used to automatically enter a random backoff mode when other active beacons are detected nearby. The detection is achieved by decoding the broadcast information of surrounding beacons or comparing GPS coordinates. The random backoff mode is as follows: before each beacon sends the next frame, a delay time is randomly selected within the range of 0~200ms to reduce the probability of signal collision caused by multiple beacons broadcasting at the same time; or, code division multiple access is used to assign different spreading codes to different beacons to achieve synchronous concurrent reception.

[0042] (III) Vehicle-mounted acoustic warning receiver like Figure 4 As shown, the vehicle-mounted acoustic warning receiver is installed in an autonomous vehicle and includes: an acoustic capture module, a signal processing and decoding module, a decision fusion and execution module, and a monitoring module.

[0043] The acoustic acquisition module consists of a microphone array composed of multiple MEMS microphone units, specifically a 4-unit array with a spacing of 4cm, used to acquire acoustic signals from the vehicle's surrounding environment in real time; the sampling rate of the microphone array is not less than 96kHz, preferably 192kHz, and the dynamic range is not less than 90dB; the acoustic acquisition module integrates a beamforming unit for time delay compensation and adaptive filtering of multi-channel signals, and employs a generalized sidelobe canceller to enhance signals from the direction of interest and suppress environmental noise.

[0044] The signal processing and decoding module is used to synchronously detect, demodulate, despread, and decode the enhanced signal output by the acoustic capture module to restore the early warning information data packet; and to perform CRC verification on the restored data packet. After the verification is passed, the event type code, action command code, beacon coordinates, and influence radius are parsed out; and the confidence factor of the decoding result is output.

[0045] The decision fusion and execution module is connected to the vehicle's existing perception system and drive-by-wire chassis system. The perception system includes a camera, lidar, and millimeter-wave radar. The decision fusion and execution module is used to calculate the relative distance based on the received beacon coordinates and influence radius, combined with the vehicle's GPS location, to determine whether to enter the warning zone. The decoded action command code is used as one of the highest priority input command sets and cross-validated with the data from the perception system. The decision fusion and execution module has a built-in priority arbitrator, which is used to trigger a preset safety arbitration strategy when acoustic commands conflict with perception data. It is also used to map the verified commands to specific underlying control actions, including deceleration, lane changing, braking, and human-machine interaction prompts, including instrument panel display, HUD display, and voice broadcast.

[0046] The priority arbitrator decides in the following order: a. Event type priority: The event type code corresponding to the emergency vehicle command is 0x02, which takes priority over the event type code 0x01 corresponding to the accident command. The accident command takes priority over the event type code 0x03 corresponding to the debris command, and so on. b. Distance Priority: Among events of the same type, the closer the vehicle is to the beacon, the higher the priority; c. Signal strength priority: If the types are the same and the distances are similar, with an error within ±10 meters, the instruction with the higher signal strength will be given priority. d. If none of the above can be distinguished, then "Caution Mode" will be triggered, including slowing down, turning on hazard lights, and requesting manual intervention.

[0047] The monitoring module is used to continuously monitor a dedicated emergency frequency band in low-power mode during vehicle operation. The specific frequency band is 22.5kHz±2kHz. It calculates the sliding cross-correlation value between the received signal and the local preamble. When the correlation peak exceeds 5 times the root mean square value of the background noise and the duration exceeds 2 symbol periods, it is determined that a valid preamble has been detected. Then, a wake-up signal is generated to wake up the signal processing and decoding module for subsequent processing.

[0048] Example 2 like Figure 5 As shown, this embodiment provides an autonomous driving warning method based on acoustic communication, applied to the above-mentioned system, including the following steps: Step 201: Event Triggering and Beacon Activation.

[0049] Based on the emergencies that occur on site, the acoustic beacons deployed on site are triggered and activated; the triggering methods include: automatic triggering by special vehicles in conjunction with the vehicle alarm system when performing tasks, or manual triggering by rescue personnel at the accident site via a physical switch.

[0050] Step 202: Beacon self-test and status monitoring.

[0051] After the beacon starts, it performs a self-test and continuously monitors its own status during operation, including: a. Power-on self-test: Checks whether the core module is working properly. The core module includes a control unit, a transmitting module, and a positioning module. If an abnormality is detected, broadcasting is prohibited and a local alarm is issued. b. Operation monitoring: Monitor the operating temperature and impedance of the transmitting module; if abnormal, automatically reduce power or suspend broadcasting; monitor beacon attitude, including tilt angle and movement status; if it exceeds the preset range, suspend broadcasting and issue a prompt; monitor power status; if the power is insufficient, reduce broadcasting power or extend the broadcasting interval.

[0052] Step 203: Generate and encode the warning information.

[0053] An acoustic beacon generates a warning information data packet matching the current event. The warning information data packet includes at least an event type code and an action command code. The event type code includes accidents, emergency vehicle passage, and debris. The action command code includes yielding to the right, lane closure ahead, and proceed with caution. A preset coding and modulation scheme is used to spread spectrum modulation and channel coding the warning information data packet, generating an acoustic digital signal frame. The coding and modulation scheme includes: using direct sequence spread spectrum technology, with a carrier frequency set to 22.5kHz ± 2kHz; channel coding using convolutional coding (2,1,7), a code rate of 1 / 2, and a generator polynomial of (171,133); the data packet is block-interleaved after encoding, with an interleaving depth of 14 rows × 16 columns. The data structure of the acoustic digital signal frame includes: a 16-bit preamble synchronization code fixed at 0xEB90, an 8-bit frame header for identifying the protocol version and priority, a 24-bit beacon ID, an 8-bit event type code, an 8-bit action command code, 32-bit longitude, 32-bit latitude, an 8-bit radius of influence, and a 16-bit CRC checksum.

[0054] Step 204: Activate directional / omnidirectional acoustic broadcasting to send early warning information.

[0055] The acoustic beacon broadcasts acoustic digital signal frames in a preset dedicated emergency frequency band through its acoustic wave transmitter. If the acoustic beacon is a mobile beacon integrated into a special vehicle, it broadcasts in a directional transmission mode toward the front of the vehicle, and the directional beam still points toward the front of the vehicle when the vehicle is reversing. If the acoustic beacon is a portable beacon deployed at the accident site, it broadcasts to the surrounding environment in an omnidirectional transmission mode.

[0056] Step 205: Multi-beacon conflict detection and backoff.

[0057] When multiple portable beacons are broadcasting simultaneously in a nearby area, collision avoidance is performed, specifically including: a. Environmental monitoring: During broadcast intervals, the beacon monitors a preset frequency band to detect the presence of broadcast signals from other beacons; b. Conflict detection: If other nearby beacons are detected, or multiple beacons are detected broadcasting simultaneously, it is determined that there is a risk of conflict; the proximity distance is determined according to the road type and the sound wave propagation attenuation model. The preset threshold is 100 meters in the highway scenario and 50 meters in the urban road scenario. c. Backoff strategy: Random backoff is adopted, that is, a random delay is made within the range of 0~200ms before sending the next frame; or code division multiple access is adopted, that is, different beacons use different spreading codes to achieve synchronous concurrent broadcasting; or time division multiplexing is adopted, that is, if the beacon has GPS time synchronization capability, different time slots are allocated for broadcasting. d. Status recovery: Normal broadcast cycle resumes after the conflict is resolved.

[0058] Step 206: Collect and receive acoustic signals for early warning information.

[0059] Autonomous vehicles in motion collect acoustic signals from the surrounding environment in real time through their onboard microphone arrays; the collected acoustic signals are then beamformed to focus on a preset direction of interest or to perform omnidirectional monitoring.

[0060] Step 207: Signal processing and instruction extraction.

[0061] The captured acoustic signal is despread, demodulated, and channel decoded to reconstruct the early warning information data packet; the reconstructed early warning information data packet is parsed to obtain the event type code and action instruction code.

[0062] Step 208: Vehicle decision integration and execution.

[0063] The parsed action command code is input into the decision-making and planning module of the autonomous vehicle. The decision-making and planning module treats the action command code as one of the highest priority inputs and cross-validates it with the perception data from the on-board sensors, including cameras, lidar, and millimeter-wave radar. If there is no conflict between the command and the perception data, the corresponding emergency behavior strategy is directly triggered, including deceleration, lane changing, and braking. If there is a conflict between the command and the perception data, a preset safety redundancy strategy is triggered, including emergency braking and issuing a warning.

[0064] Step 209: Periodic broadcasting and dynamic updates.

[0065] The acoustic beacon broadcasts warning information cyclically at a preset time interval of 1 second; wherein, the mobile beacon dynamically updates its location or status information in the broadcast content.

[0066] In addition, before step 206, there is also a monitoring step on the vehicle receiver side: during vehicle operation, the monitoring module continuously monitors the dedicated emergency frequency band in low power mode, calculates the sliding cross-correlation value between the received signal and the local preamble, and when the correlation peak exceeds 5 times the root mean square value of the background noise and the duration exceeds 2 symbol periods, it is determined that a valid preamble has been detected, and then a wake-up signal is generated to wake up the subsequent signal processing and decoding modules.

[0067] In step 208, during the cross-validation process, if there are multiple acoustic commands or if the acoustic commands conflict with the sensing data, a decision is made according to the priority arbitration rules, which include: a) event type priority; b) distance priority; c) signal strength priority; d) if they cannot be distinguished, a "cautious mode" is triggered.

[0068] The technical means disclosed in this invention are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention.

Claims

1. An autonomous driving early warning system based on acoustic wave communication, characterized in that, include: At least one on-site acoustic beacon, set up at the scene of an emergency, is used to broadcast an acoustic digital signal containing early warning information in response to the triggering of the event; At least one vehicle-mounted acoustic warning receiver is installed in the autonomous vehicle to capture and decode the acoustic digital signals broadcast by the on-site acoustic beacon in real time, extract warning information and send it to the vehicle decision-making level for execution; The on-site acoustic beacon and the vehicle-mounted acoustic warning receiver communicate unidirectionally via sound waves on a preset dedicated emergency frequency band, with the communication path independent of the wireless cellular network and roadside infrastructure.

2. The autonomous driving early warning system according to claim 1, characterized in that, The on-site acoustic beacon includes a mobile acoustic beacon integrated into a special vehicle, which includes: The trigger interface module is used to generate trigger signals in response to the emergency mission status of special vehicles; The control and encoding module is used to generate a data packet containing early warning information after receiving a trigger signal, and to perform channel coding and spread spectrum modulation on the data packet to generate an acoustic digital signal frame. A directional transmission module is used to broadcast the acoustic digital signal frame in a directional mode within a preset dedicated emergency frequency band.

3. The autonomous driving early warning system according to claim 2, characterized in that, The directional transmission module of the mobile acoustic beacon consists of multiple ultrasonic transducer units, configured to broadcast based on the vehicle's current heading angle in the direction the vehicle is facing. When the vehicle is reversing, the directional beam still points in the direction the vehicle is facing. The mobile acoustic beacon also includes a status monitoring module, which is used to monitor the working status of the transmission module in real time and issue a prompt when there is an abnormality.

4. The autonomous driving warning system according to claim 1, characterized in that, The on-site acoustic beacon includes a portable acoustic beacon, which is manually placed by rescue personnel and includes: The switch module is used to control the beacon's activation and deactivation. The positioning module is used to obtain the real-time geographical coordinates of the beacon and detect its movement. The control and encoding module is used to generate a data packet containing warning information after receiving a broadcast start command, and to perform channel coding and spread spectrum modulation on the data packet to generate an acoustic digital signal frame. An omnidirectional transmission module is used to broadcast the acoustic digital signal frame in omnidirectional mode within a preset dedicated emergency frequency band; The power supply module is used to supply power to each module.

5. The autonomous driving warning system according to claim 4, characterized in that, The portable acoustic beacon also includes a collision detection module, which controls the beacon to enter a random backoff mode when other active beacons are detected nearby. The random backoff mode includes randomly selecting a delay time before sending the next frame, or using code division multiple access to assign different spreading codes to different beacons.

6. The autonomous driving warning system according to claim 4, characterized in that, The portable acoustic beacon also includes an auxiliary safety module, which includes a tilt sensor to detect whether the beacon is tilted and to automatically stop broadcasting and issue an alarm when the tilt angle exceeds a preset threshold.

7. The autonomous driving warning system according to claim 1, characterized in that, The vehicle-mounted acoustic warning receiver includes: The acoustic capture module consists of a microphone array composed of multiple MEMS microphone units, used to acquire acoustic signals from the vehicle's surrounding environment in real time, and integrates a beamforming unit to enhance signals from the direction of interest. The signal processing and decoding module is used to synchronously detect, demodulate, despread, and decode the captured acoustic signals to restore the early warning information data packets and parse the event type code and action command code. The decision fusion and execution module connects with the vehicle's original perception system and drive-by-wire chassis system to perform cross-validation based on the received warning information and map the validated instructions to the underlying control actions. The monitoring module is used to continuously monitor the dedicated emergency frequency band in a low-power mode during vehicle operation, and generate a wake-up signal to wake up the signal processing and decoding module when a valid preamble is detected.

8. The autonomous driving warning system according to claim 7, characterized in that, The decision fusion and execution module has a built-in priority arbitrator, which is used to trigger a preset security arbitration strategy when acoustic commands and perception data conflict. The priority arbitrator decides in the following order: a) event type priority; b) distance priority; c) signal strength priority; d) if it cannot be distinguished, "caution mode" is triggered.

9. An autonomous driving early warning method based on acoustic wave communication, characterized in that, Includes the following steps: Step a: Event Triggering and Beacon Activation. Based on the unexpected events that occur on-site, trigger and activate the acoustic beacons deployed on-site. Step b: Generate and encode warning information. The acoustic beacon generates a warning information data packet that matches the current event, and performs channel coding and spread spectrum modulation on the data packet to generate an acoustic digital signal frame. Step c: Start acoustic broadcasting. The acoustic beacon broadcasts the acoustic digital signal frame in a preset dedicated emergency frequency band through its acoustic wave transmitter. Step d: Acquisition and reception. The autonomous vehicle in motion acquires acoustic signals from the surrounding environment in real time through the onboard microphone array and performs beamforming processing on the acquired signals. Step e: Signal processing and command extraction, demodulating, despreading and channel decoding of the captured acoustic signal to restore the warning information data packet, and parsing to obtain the event type code and action command code; Step f: Decision fusion and execution. The parsed action command code is input into the decision planning module of the autonomous vehicle, cross-validated with the perception data of the on-board sensors, and the corresponding emergency behavior strategy is triggered based on the verification result.

10. The autonomous driving early warning method according to claim 9, characterized in that, When multiple portable beacons broadcast simultaneously in a nearby area, a collision detection and backoff procedure is also included: during the broadcast interval, the beacon listens to a preset frequency band to detect whether there are broadcast signals from other beacons; If a conflict risk is determined, a backoff strategy is executed, which may include random backoff, code division multiple access, or time division multiplexing.

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