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CN-121999634-A - Emergency active early warning system based on vehicle-to-vehicle radio direct communication

CN121999634ACN 121999634 ACN121999634 ACN 121999634ACN-121999634-A

Abstract

The invention discloses an emergency active early warning system based on vehicle-to-vehicle radio direct communication. The system comprises an accident detection module, a communication control module and a radio transceiver module. The accident detection module judges the accident through the multi-source signal fusion probability model, and the communication control module controls the radio receiving and transmitting module to broadcast the standardized digital pre-alarm message with the self-adaptive transmitting power according to the accident priority, and simultaneously receives and processes the other vehicle message. The system supports voice communication, and can provide early warning prompt through a man-machine interaction module or link the advanced driving auxiliary system of the vehicle through an external interface to execute automatic emergency braking and other operations. The invention realizes reliable detection of accident information, low delay broadcast of beyond visual range and cooperative active response of vehicles, and effectively improves the road traffic safety level.

Inventors

  • ZHAO YINGWU

Assignees

  • 赵应伍

Dates

Publication Date
20260508
Application Date
20251219

Claims (10)

  1. 1. Emergency active early warning system based on radio direct communication of car to car, its characterized in that, the system sets up in the vehicle is inside, includes: The accident detection module is used for monitoring the safety state of the vehicle and generating a trigger signal when the condition of meeting the preset accident is detected; The communication control module is electrically connected with the accident detection module and is used for receiving the trigger signal and generating a standardized digital pre-alarm message containing accident vehicle state information according to the signal; The radio transceiver module is connected with the communication control module and is configured to work in a preset public special frequency band; The communication control module controls the radio transceiver module to send the standardized digital pre-alarm message to surrounding vehicles in a broadcasting mode according to the accident type or the triggering source corresponding to the triggering signal, and meanwhile, the communication control module controls the radio transceiver module to continuously monitor the public special frequency band so as to receive and process the digital pre-alarm message broadcasted by other vehicles.
  2. 2. The active emergency early warning system based on vehicle-to-vehicle radio direct communication according to claim 1, wherein the accident detection module specifically comprises: an airbag sensor interface unit for acquiring a triggering state of an airbag of a vehicle; the emergency braking signal interface unit is used for acquiring a manual activation signal of an emergency braking or danger warning lamp of the vehicle; The manual alarm unit is used for actively triggering an alarm signal by a driver; the safety airbag sensor interface unit, the emergency braking signal interface unit and the manual alarm unit respectively provide the signals generated by the safety airbag sensor interface unit, the emergency braking signal interface unit and the manual alarm unit as the trigger signals to the communication control module; The decision logic of the accident detection module is based on a probability model of multi-source signal fusion, and when a plurality of trigger signal combinations received by the communication control module meet the following conditions, the decision confidence of the accident severity is improved: Where P (Accident |S 1 ,S 2 ,...,S n ) represents the posterior probability of a real accident occurring given n detection signals S 1 ,S 2 ,...,S n (e.g., airbag trigger S airbag , emergency brake S brake , manual alarm S manual ), P (S i | Accident) represents the conditional probability that signal S i is triggered at the time of a real accident, and P 0 (Accident) represents the prior probability of an accident occurring, which is used to quantify the comprehensive probability of an accident occurring when multiple signal sources are triggered simultaneously or sequentially, providing a more reliable basis for the broadcast decisions of the communication control module.
  3. 3. The emergency active early warning system based on the vehicle-to-vehicle radio direct communication according to claim 2, wherein the communication control module executes a multi-stage triggering and broadcasting range adaptive strategy, specifically: When the triggering signal is from the safety airbag sensor interface unit, determining that the safety airbag sensor interface unit is in a highest priority accident, and controlling the radio transceiver module to broadcast at a first preset maximum power by the communication control module; when the trigger signal is derived from the emergency alarm initiated by the emergency brake signal interface unit or the manual alarm unit, determining that the emergency alarm is a next highest priority alarm, and controlling the radio transceiver module to broadcast at a second power lower than a first preset maximum power by the communication control module; when a non-emergency driving safety prompt is initiated through the manual alarm unit, judging that the vehicle is a normal priority prompt, and controlling the radio transceiver module to broadcast with the lowest third power by the communication control module; the first, second, and third power values are calculated and determined according to a preset expected coverage radius R target and a path loss model, and are specifically determined by the following formula: Where P tx is the required transmit power (in dBm), P rx_min is the receiver sensitivity (in dBm), L 0 is the path loss (in dB) at a reference distance d 0 (typically 1 meter), gamma is the path loss index, R target is the effective coverage radius of the desired signal at the corresponding priority, and X σ is the shadow fading margin (in dB) subject to a zero-mean normal distribution N (0, sigma 2 ), by setting different R target values for different priorities (e.g. ) And substituting the above formula to calculate corresponding adaptive transmitting power Thereby realizing the self-adaptive matching of the broadcasting range and the accident severity.
  4. 4. The system of claim 1 or 3, wherein the standardized digital pre-alarm message is a structured data frame, and at least comprises a message type identifier for identifying an accident or reminding type, a trigger source type field for representing a trigger source, a unique identification code for transmitting a vehicle, real-time longitude and latitude coordinates of the vehicle, and a time stamp.
  5. 5. The emergency active early warning system based on the vehicle-to-vehicle radio direct communication according to claim 1, further comprising an audio encoding and decoding unit and an in-vehicle audio input and output device connected with the communication control module; the radio transceiver module further supports establishing a half-duplex or full-duplex voice communication link over the common dedicated frequency band; when the radio transceiver module receives a voice communication request or a driver initiates voice communication through the in-vehicle audio input/output device, the communication control module switches to a voice communication mode, so that the driver can perform voice interaction with a driver of an adjacent vehicle.
  6. 6. The emergency active early warning system based on the vehicle-to-vehicle radio direct communication according to claim 1, further comprising a man-machine interaction module connected with the communication control module; When the radio transceiver module receives the digital pre-alarm message from other vehicles, the communication control module analyzes the message, and provides visual and/or audible early warning prompts at least comprising accident direction, relative distance and severity level for the driver of the vehicle through the man-machine interaction module according to the type identification and the position information in the message.
  7. 7. The vehicle-to-vehicle radio direct communication based emergency active early warning system of claim 6, wherein the communication control module is further configured to: Calculating the accident azimuth and the relative distance according to the analyzed position information of the other vehicle and the real-time position information of the own vehicle; analyzing the approaching or separating trend of the vehicle relative to the accident source according to the position information change or the signal intensity change in the same accident source message which is continuously received; the analysis result is provided for a driver through the man-machine interaction module; The relative distance D is calculated by a ground subject calculation formula or a plane approximation formula, and the plane approximation formula is as follows: Wherein (x t ,y t ) is the plane coordinate of the accident source vehicle (obtained by projection conversion from longitude and latitude), and (x r ,y r ) is the plane coordinate of the vehicle, and the accident azimuth θ (0 degree in north and clockwise increment) is calculated by the following formula: Wherein arctan2 is a four-quadrant arctangent function, the approaching or separating trend is judged by calculating the distance variation delta D=D3835 in two continuous message periods, if delta D < -, delta p # -, the approaching or separating trend is calculated by calculating the distance variation delta D=D k -D k-1 A proximity determination threshold value), then determining a proximity trend, if It is determined to be far away.
  8. 8. The emergency active early warning system based on the car-to-car radio direct communication according to claim 1, wherein the communication control module is further provided with an external system interface, and is used for sending key information in the received and parsed digital early warning message or a control instruction generated according to the message to an advanced driving auxiliary system or a car body control unit of the car so as to trigger at least one action of automatic emergency braking, self-adaptive cruise control adjustment, early warning acousto-optic prompt or automatic on of a hazard warning lamp; Wherein one of the decision conditions triggering automatic emergency braking is described by the following formula: And v r >v t Wherein TTC (TimetoColision) is the predicted collision time, D is the relative distance between the host vehicle and the accident source vehicle, v r is the host vehicle speed, v t is the accident source vehicle speed (if the message contains speed information, otherwise set to 0), And when the TTC is smaller than or equal to the threshold and the speed of the vehicle is larger than the speed of the front vehicle, the communication control module sends a forced braking request to the advanced driving auxiliary system through an external system interface.
  9. 9. The emergency active early warning system based on the vehicle-to-vehicle radio direct communication according to claim 1, wherein the communication control module is pre-stored with an early warning message history record broadcasted by an adjacent vehicle; the communication control module marks a continuously existing accident risk area according to the history record and the information of the current received message, and provides a navigation auxiliary prompt through the man-machine interaction module; The dynamic identification of the risk area is based on a space-time clustering algorithm, and early warning events adjacent in position within a time window delta T are aggregated into a risk cluster C k , the risk center of which And risk intensity I k is calculated as follows: Wherein, (Lon i ,Lat i ) is longitude and latitude coordinates in an ith early warning message, w i is weight given to the message based on received signal intensity or Priority, N k is the number of early warning events in a cluster C k , priority i is the Priority value of the ith event, alpha and beta are coefficients for adjusting the weights of frequency factors and severity factors, and risk intensity I k is used for identifying risk levels of risk areas in different colors or sizes on a human-computer interaction interface.
  10. 10. The emergency active early warning system based on the vehicle-to-vehicle radio direct communication according to claim 1, wherein the direct communication protocol adopted by the radio transceiver module is compatible with a vehicle-to-vehicle communication mode in a cellular vehicle networking or special short-range communication standard; The communication control module adopts a back-off algorithm to adjust message sending time when a channel is congested, the size CW of a back-off window is dynamically adjusted according to network load, and an adjustment strategy is controlled by the following formula: Assuming that the current channel busy ratio is BR (the ratio of channel busy detected per unit time), the contention window base CW base is adjusted to: CW base ＝min(CW max ,CW min ·exp(λ·BR)) The actual backoff slot number BackoffSlots is uniformly and randomly selected within the interval [0, CW base -1 ]: in the formula, And The algorithm increases the average back-off time when the network load BR increases, thereby reducing the probability of message collision and guaranteeing the sending reliability of the high-priority pre-alarm message in a congestion environment.

Description

Emergency active early warning system based on vehicle-to-vehicle radio direct communication Technical Field The invention relates to the technical field of intelligent traffic safety, in particular to an emergency active early warning system based on vehicle-to-vehicle radio direct communication. Background In the running process of a traffic system, the continuous rear-end collision accidents in the scenes of expressways, urban expressways and the like continuously form a great safety risk. Such secondary collision events are often triggered by superposition of multiple factors, including line of sight obstruction caused by road alignment, visibility dip under severe weather conditions, driver distraction, failure of accident information delivery mechanisms, and the like. The prior early warning technology system has systematic defects that the effectiveness of the visual passive warning means, such as a hazard warning flash lamp or a triangular warning board, is highly dependent on the visual observation capability of a rear driver, the warning effect is weakened sharply under the complex environments of haze, heavy rain, night or sharp bend road sections and the like, and the physical propagation distance is extremely limited, so that a sufficient decision time window cannot be provided for a high-speed driving vehicle. The early warning scheme based on the cellular mobile network uploads accident information to the cloud end through the vehicle-mounted communication module and redistributes the accident information, but the route introduces significant communication delay, so that the early warning information lags behind the accident development process, and meanwhile, the scheme is completely limited by the coverage continuity and stability of the cellular network, and the function is completely lost in remote areas, tunnels or network congestion scenes. Although the vehicle-road cooperative technology can transmit risk information by means of road side equipment, large-scale deployment faces the real bottlenecks of high infrastructure construction cost, long maintenance period and the like, and the global coverage capacity is difficult to form in a short period. Although the special short-range communication and cellular internet of vehicles standard define the vehicle-to-vehicle communication mode, the prior implementation lacks a deep coupling mechanism with a vehicle safety system, and can not realize the automatic activation of early warning at the moment of accident such as the triggering of an air bag, and the broadcasting strategy also has the rigidification problem, and the signal coverage range can not be dynamically adjusted according to the severity of the accident, so that the high-priority early warning information is not spread enough or the low-priority information excessively occupies channel resources. Especially in areas without network coverage, the prior art systems cannot operate independently, and such environments are precisely secondary accident-prone zones. Disclosure of Invention In view of the foregoing, it is desirable to provide an active early warning system for emergency based on vehicle-to-vehicle radio direct communication, so as to solve or alleviate the technical problems in the prior art. The technical scheme of the embodiment of the invention is realized by an emergency active early warning system based on vehicle-to-vehicle radio direct communication, wherein the system is arranged in a vehicle and comprises the following components: The accident detection module is used for monitoring the safety state of the vehicle and generating a trigger signal when the condition of meeting the preset accident is detected; The communication control module is electrically connected with the accident detection module and is used for receiving the trigger signal and generating a standardized digital pre-alarm message containing accident vehicle state information according to the signal; The radio transceiver module is connected with the communication control module and is configured to work in a preset public special frequency band; The communication control module controls the radio transceiver module to send the standardized digital pre-alarm message to surrounding vehicles in a broadcasting mode according to the accident type or the triggering source corresponding to the triggering signal, and meanwhile, the communication control module controls the radio transceiver module to continuously monitor the public special frequency band so as to receive and process the digital pre-alarm message broadcasted by other vehicles. The embodiment of the invention adopts the technical scheme that the method has the advantages that the defect that a single sensor is easy to report by mistake and missed report is effectively overcome through deep coupling of a probability model fused by multi-source signals and a vehicle safety system, the reliability of accident detection is obviously impr