Automobile emergency response message processing method based on Beidou short message

Abstract

The invention provides an automobile emergency response message processing method based on a Beidou short message, and relates to the technical field of intelligent automobile safety, and the method comprises the steps: S1, monitoring whether an automobile fault or accident index is generated or not in real time; s2, automatically triggering or manually triggering the generation of a short message used by communication in a vehicle fault state; s3, compressing the generated short message into a data packet, and uploading the data packet to a Beidou satellite; s4, sending the information to a preset rescue platform through a Beidou satellite communication module; the vehicle state acquisition module, the Beidou short message communication module, the trigger control unit and the message generation engine are applied to the automobile emergency response message processing method. According to the technical key points, an optimal satellite combination is automatically selected to carry out positioning calculation through a Beidou / GPS dual-mode positioning mode, the reliability of position data can be improved, the coverage range is wide, the dependence of manual operation is reduced through an automatic triggering mechanism, and the probability of personnel survival is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent vehicle safety, and in particular, to a method for processing automotive emergency response messages based on Beidou short messages. Background Art

[0002] Beidou short message refers to Beidou regional short message communication. The Beidou short message communication service is provided by the radio frequency signals in the L band and S band of 3 GEO satellites in Beidou-3. Simply put, Beidou short message communication is actually similar to the "short message" we usually use. The Beidou short message could only send 120 Chinese characters at first, and now it can send 1000 Chinese characters of information at a time. It can not only use the positioning function to obtain positioning information, but also send information to the outside through the short message function.

[0003] The Beidou short message function is an important communication capability in the Beidou satellite navigation system, which allows users to send and receive text information through Beidou satellites. Specifically, users can use this function to transmit short text information to other users or ground stations through Beidou satellites, and vice versa. This communication method is particularly important in some specific scenarios. For example, in remote areas, oceans, deserts and other places where ground communication infrastructure cannot be covered, or in natural disasters, emergency rescues and other situations when the ground communication network is paralyzed, the Beidou short message function can provide a reliable communication means to ensure the transmission and communication of information. When designing Beidou positioning satellites in China, full consideration was given to the communication capabilities of the satellites, and the communication capabilities and positioning capabilities were combined to design the ability to send and receive short messages bidirectionally. That is to say, we can use Beidou satellites to send short messages and also receive short messages.

[0004] Automotive emergency is a method for dealing with various emergencies that occur during the driving process of an automobile. An automobile may encounter various emergencies on the road, such as being tilted on the road shoulder, the wheels running off the road shoulder and hanging in the air, the vehicle body rolling over, the engine braking failing, sliding downwards when going uphill, a tire suddenly bursting during driving, a vehicle catching fire during driving, an automobile overturning, an automobile falling into water and other emergency situations. When an automobile requests emergency assistance, the vehicle uses a cellular network (such as 4G / 5G) or the user actively makes a call to inform the information.

[0005] However, the traditional in-vehicle SOS system is limited by the network coverage, and the manually triggered distress device depends on the user's operation ability. In areas without network coverage (such as uninhabited areas, mountainous areas) or when the accident causes the personnel to be unconscious, the risk of rescue delay is extremely high, greatly reducing the survival rate of the accident victims. Summary of the Invention

[0006] To overcome the deficiencies that the existing in-vehicle SOS system is limited by the network coverage, and the manual trigger-type distress device relies on the user's operation ability, resulting in a very high risk of rescue delay in areas without network coverage or when the accident causes the person to be unconscious, greatly reducing the survival rate of accident victims, the embodiments of this application provide a method for processing automotive emergency response messages based on Beidou short messages. By using the Beidou / GPS dual-mode positioning method, when the dual-mode positioning device receives the signals of Beidou satellites and GPS satellites simultaneously, the built-in algorithm and processing mechanism automatically select the optimal satellite combination for positioning calculation according to various factors such as signal quality, number of satellites, and positioning accuracy, which can improve the reliability of position data and has a wider coverage range;

[0007] Meanwhile, by configuring two modes for vehicles in a fault state, namely an automatic trigger short message sending program and manually sending a rescue request, when it is difficult for the people in the vehicle to use manual assistance due to injury or unconsciousness, etc., a short message is directly generated by means of automatic trigger control and compressed, and two-way information transmission is carried out between the vehicle and the rescue platform by the Beidou satellite communication module, facilitating the vehicle in a fault to get help in the first time and greatly increasing the survival probability of the people.

[0008] The technical solution adopted by the embodiments of this application to solve its technical problems is:

[0009] A method for processing automotive emergency response messages based on Beidou short messages, including

[0010] S1: Real-time monitoring whether vehicle fault or accident indicators occur;

[0011] S2: Generating short messages used for automatic or manual trigger communication in the vehicle fault state;

[0012] S3: Compressing the generated short messages into data packets and uploading them to Beidou satellites;

[0013] S4: Sending them to a preset rescue platform through the Beidou satellite communication module.

[0014] In a possible implementation manner, it includes a vehicle status acquisition module, a Beidou short message communication module, a trigger control unit, and a message generation engine applied to this method for processing automotive emergency response messages;

[0015] Among them, the vehicle status acquisition module is used for real-time monitoring of faults such as collision sensors, airbag trigger signals, and abnormal battery voltage; the Beidou short message communication module is internally configured with a Beidou RDSS (Radio Determination Service) chip for supporting two-way communication; the trigger control unit includes an automatic trigger control and a manual trigger button; the message generation engine is used for compressing the vehicle VIN code, GPS / Beidou dual-mode positioning data, fault codes, time stamps, etc. into data packets conforming to the Beidou short message format.

[0016] In a possible implementation, the automatic trigger control in the trigger control unit is controlled by the threshold of the automatic trigger condition, and the threshold formula of the automatic trigger condition is:

[0017]

[0018] Wherein, is the average value of the monitoring index x (x is the number of fault factors such as collision sensors, airbag trigger signals, abnormal battery voltages, etc.) within a period of time;

[0019] σ is the standard deviation of the monitoring index x within the same time period, which is used to measure the degree of data dispersion;

[0020] k is a constant that can be adjusted according to specific circumstances, and it determines the deviation degree of the threshold relative to the average value.

[0021] In a possible implementation, the manual trigger button in the trigger control unit allows the user to initiate a distress signal through the in-vehicle central control screen or the physical SOS button, and secondary confirmation is supported to prevent accidental triggering.

[0022] In a possible implementation, when the short message is transmitted to the preset rescue platform by the Beidou satellite communication module, the number of short message transmissions N within a certain time is calculated by the following formula:

[0023]

[0024] Wherein, T is the total time period; t is the time interval for each short message transmission;

[0025] If the transmission time interval of the short message is not fixed, or there are other limiting conditions, such as network delay, transmission success rate, etc., the actual number of transmissions may be less than the theoretical calculated number. Introducing a success rate factor p (0 < p ≤ 1), then the actual number of transmissions

[0026] N 实际 = N * p.

[0027] In a possible implementation, the vehicle system in the monitoring state in S1 sets a fault level for vehicle faults, aggregates the existing faults of the vehicle into a set F, and divides the total fault set F into n1 major categories according to the general nature or influence range of the faults, denoted as Satisfy And

[0028] For each major category F in the first-level classification 1k(k = 1, 2, …, n1), and further subdivided into n2 small categories denoted as Satisfy And

[0029] And so on for secondary classification, thus supporting the work of adjusting the priority of short message sending.

[0030] In a possible implementation, in S3, in the form of a dynamic message compression algorithm, the volume of the data packet is optimized to the single - transmission capacity of Beidou short messages and supports extended fields.

[0031] In a possible implementation, the dynamic message compression algorithm can use the LZMA algorithm including three coding forms: dictionary coding, Huffman coding, and arithmetic coding;

[0032] Among them, in dictionary coding, LZMA uses a sliding window as a dictionary. Assuming the window size is W, during the compression process, it will search for the longest phrase in this window that matches the current data to be compressed;

[0033] Let the current character sequence to be compressed be S, the longest matching phrase found in the window be P, its length be L, and the position of the phrase in the window be D (the offset from the current position). Then this match can be represented by the triple (D, L, C) (C is the single character remaining after the match);

[0034] For the result after dictionary coding, that is, information such as (D, L, C), Huffman coding is used for further compression. Huffman coding constructs a Huffman tree according to the frequency of character occurrence. Characters with high frequencies have short codes, and characters with low frequencies have long codes, as follows:

[0035] Let the character be x i The frequency of occurrence is f(x i ), and its Huffman coding length is l(x i ), then the average code length L avg = ∑ i f(x i ) * l(x i ), through the construction of the Huffman tree, L avg is minimized;

[0036] In arithmetic coding, the probability distribution of the entire message is mapped to a real - number interval [0, 1], and the message is represented by continuously subdividing this interval;

[0037] Assume the message consists of characters x1, x2, …, x ncomponents, with probabilities p(x1), p(x2), …, p(x n ). Initially, the interval is [L0, R0) = [0, 1). For the first character x1, the new interval becomes [L1, R1) = [L0, L0 + p(x1) * (R0 - L0)). And so on, for the i-th character x i , the interval is updated to [L i , R i ) = [L i-1 , L i-1 + p(x i ) * (R i-1 - L i-1 ). Finally, a suitable coding value is selected in the interval [L n , R n ) to represent the entire message.

[0038] In a possible implementation, when the vehicle in S1 is in a fault, Beidou / GPS dual-mode positioning is adopted. The dual-mode positioning device for implementing the dual-mode positioning method simultaneously receives the signals of Beidou satellites and GPS satellites, and through the built-in algorithm and processing mechanism, according to various factors such as signal quality, number of satellites, and positioning accuracy, automatically selects the optimal satellite combination for positioning calculation.

[0039] The beneficial effects of this application are as follows:

[0040] First, in this solution, by using the Beidou / GPS dual-mode positioning method, when the dual-mode positioning device simultaneously receives the signals of Beidou satellites and GPS satellites, the built-in algorithm and processing mechanism automatically select the optimal satellite combination for positioning calculation according to various factors such as signal quality, number of satellites, and positioning accuracy, which can improve the reliability of position data and has a wide coverage range;

[0041] Second, in this solution, by configuring two modes of automatically triggering the short message sending program and manually requesting rescue for the vehicle in a fault state, when it is difficult for the people in the vehicle to use manual rescue due to being injured or unconscious, etc., a short message is directly generated by means of automatic trigger control and compressed, and two-way information transmission is carried out between the vehicle and the rescue platform by the Beidou satellite communication module, which is convenient for the vehicle in a fault to get help in the first time and greatly improves the survival probability of people;

[0042] Third, in this solution, by setting a multi-frequency retransmission mode for the automatically triggered Beidou short message sending when the vehicle is in a fault state, if the vehicle does not receive the confirmation receipt from the rescue platform after the first sending, the Beidou short message is re-sent after an interval of time until the confirmation receipt sent by the rescue platform is received, which can avoid the problem that the information transmission between the vehicle and the rescue platform is not completed and affects the timely rescue of the vehicle;

[0043] Fourthly, in this solution, by summarizing the possible vehicle fault types and classifying different faults according to the vehicle damage and the degree of harm to personnel caused by different faults, when using the automatically triggered control mode configured in the vehicle to send short messages, the sending priority of the short messages can be adjusted, which is convenient for using extremely priority resources to generate the optimal rescue plan;

[0044] Fifthly, in this solution, by using the dynamic message compression algorithm to optimize the data packet volume to the single - transmission capacity of Beidou short messages, the vehicle in a fault state can add compressed extension fields, which is conducive to completing the transmission of specific information through a small number of short messages and reducing the pressure of data transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a schematic flowchart of a method for processing automotive emergency response messages based on Beidou short messages according to the present invention;

[0046] Figure 2 is a system block diagram of a method for processing automotive emergency response messages based on Beidou short messages according to the present invention;

[0047] Figure 3 is a schematic flowchart of a method for processing automotive emergency response messages based on Beidou short messages according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0048] The technical solutions in the embodiments of the present application are to solve the problems in the above - mentioned background technology, and the general idea is as follows:

[0049] Embodiment 1:

[0050] This embodiment introduces the specific structure of a method for processing automotive emergency response messages based on Beidou short messages. Specifically, referring to Figures 1 - 3 as shown, it includes:

[0051] S1: Real - time monitor whether vehicle fault or accident indicators occur;

[0052] Among them, when the vehicle is in a fault, Beidou / GPS dual - mode positioning is used for positioning. The dual - mode positioning device for realizing the dual - mode positioning method simultaneously receives the signals of Beidou satellites and GPS satellites, and through the built - in algorithm and processing mechanism, automatically selects the optimal satellite combination for positioning calculation according to various factors such as signal quality, the number of satellites, and positioning accuracy;

[0053] S2: Automatically trigger or manually trigger the generation of short messages used for communication in the vehicle fault state;

[0054] S3: Compress the generated short messages into data packets and upload them to Beidou satellites;

[0055] S4: Transmitted to a preset rescue platform via the Beidou satellite communication module;

[0056] Among them, when using the Beidou satellite communication module for information transmission, the short message sender first encrypts the communication application signal containing the recipient ID number and communication content and forwards it into the station via the satellite; after receiving the communication application signal, the ground central station decrypts and re-encrypts it and then adds it to the continuously broadcast outbound broadcast telegram, which is broadcast to users via the satellite; the recipient user terminal receives the outbound signal, demodulates and decrypts the outbound telegram, and completes a communication (similar to the positioning function, the transmission delay of short message communication is about 0.5 seconds, and the highest communication frequency is also once per second);

[0057] Secondly, it includes a vehicle status acquisition module (for real-time monitoring of faults such as collision sensors, airbag trigger signals, and abnormal battery voltages), a Beidou short message communication module (internally configured with a Beidou RDSS (Radio Determination Service) chip for supporting two-way communication), a trigger control unit (including automatic trigger control and a manual trigger button), and a message generation engine (for compressing vehicle VIN codes, GPS / Beidou dual-mode positioning data, fault codes, timestamps, etc. into data packets conforming to the Beidou short message format);

[0058] The automatic trigger control in the trigger control unit is controlled by the automatic trigger condition threshold, and the threshold formula for the automatic trigger condition is:

[0059]

[0060] Among them, is the average value of the monitoring index x (x is the number of fault factors such as collision sensors, airbag trigger signals, and abnormal battery voltages) within a period of time;

[0061] σ is the standard deviation of the monitoring index x within the same period of time, which is used to measure the degree of data dispersion;

[0062] k is a constant that can be adjusted according to specific circumstances, and it determines the deviation degree of the threshold relative to the average value (if k = 2, it means the threshold is set to the average value plus twice the standard deviation);

[0063] When the value of the monitoring index x exceeds the average value plus a certain multiple of the standard deviation, it is considered that an abnormal situation has occurred, thus triggering the automatic sending of short messages.

[0064] In some examples, the manual trigger button in the trigger control unit is used by the user to initiate a distress signal through the vehicle-mounted central control screen or the physical SOS button, and secondary confirmation is supported to prevent accidental triggering. Based on the combination of automatic trigger control, a dual-trigger mode fusion state is formed, which can cover all-scenario emergency requirements as much as possible.

[0065] The above design uses the Beidou / GPS dual-mode positioning method. When the dual-mode positioning device receives the signals of Beidou satellites and GPS satellites simultaneously, the built-in algorithm and processing mechanism automatically selects the optimal satellite combination for positioning calculation according to various factors such as signal quality, the number of satellites, and positioning accuracy, which can improve the reliability of position data, has a wide coverage range, breaks through the cellular network limit, and is applicable to the global Beidou signal coverage area (especially in scenarios without ground network).

[0066] At the same time, by configuring two modes of automatic trigger short message sending program and manually sending a rescue request for vehicles in a fault state, when it is difficult for the people in the vehicle to use manual assistance due to injury or unconsciousness, etc., a short message is directly generated by means of automatic trigger control and compressed, and the Beidou satellite communication module performs two-way information transmission between the vehicle and the rescue platform, facilitating the vehicle in a fault to get help in the first time.

[0067] It should be noted that between the manual trigger button and the automatic trigger control, if the actual monitoring index in the automatic trigger control is less than the required trigger condition threshold T, the manual trigger button can be operated for rescue work; if the actual monitoring index in the automatic trigger control is greater than the required trigger condition threshold T, it is determined that an abnormal situation has occurred, thus triggering the automatic sending of a short message, and completely ignoring whether the manual trigger button is activated (that is, the automatic trigger control is superior to the manual trigger button).

[0068] Embodiment 2:

[0069] Based on Embodiment 1, this embodiment introduces the specific mode of multi-frequency retransmission of Beidou short messages. The short messages generated for automatic trigger or manual trigger communication in the vehicle fault state are compressed into data packets and uploaded to the Beidou satellite.

[0070] Among them, after the short message is sent for the first time, if the confirmation receipt from the rescue platform is not received, it will be automatically retransmitted every 2 minutes, up to 3 times. When it is transmitted to the preset rescue platform by the Beidou satellite communication module, the following formula is used to calculate the number of short message transmissions N within a certain time:

[0071]

[0072] Among them, T is the total time period; t is the time interval for each short message transmission.

[0073] If the sending time interval of the short message is not fixed, or there are other limiting conditions, such as network latency, sending success rate, etc., the actual number of transmissions may be less than the theoretically calculated number. Introduce a success rate factor p (0 < p ≤ 1), then the actual number of transmissions N 实际 = N * p (For example, if a short message is to be sent every 120 seconds within 6 minutes (T = 360 seconds), then the number of transmissions

[0074] );

[0075] The above design sets a multi-frequency retransmission mode for the automatically triggered Beidou short message sending when the vehicle is in a fault state. If the vehicle does not receive the confirmation receipt from the rescue platform after the first sending, it will resend the Beidou short message after a period of time until it receives the confirmation receipt sent by the rescue platform, which can avoid the problem that after a single short message is sent, the information transmission between the Beidou satellite communication module and the rescue platform is not completed, resulting in the vehicle not obtaining the confirmation information feedback from the rescue platform and affecting the timely rescue of the vehicle.

[0076] Embodiment 3:

[0077] Based on Embodiment 1, this embodiment introduces the specific scheme for vehicle fault classification. During the process of the vehicle system monitoring in real time whether vehicle fault or accident indicators occur, it is confirmed that the vehicle fault state includes but is not limited to the values monitored by the collision sensor (the collision acceleration detected by the vehicle sensor ≥ 5g), the airbag trigger signal, the abnormal battery voltage and other faults;

[0078] Among them, the vehicle system in the monitoring state sets a fault level for the vehicle fault, aggregates the existing faults of the vehicle into a set F, and divides the total fault set F into n1 major categories according to the general nature or influence range of the faults, denoted as Satisfying And

[0079] For each major category F in the first-level classification 1k (k = 1, 2,..., n1), it is further divided into n2 sub-categories denoted as Satisfying And

[0080] For each major category F in the second-level classification 2k (k = 1, 2,..., n1), it is further divided into n3 sub-categories denoted as Satisfying And And so on for secondary classification; at this time, according to the fault types in the first, second, and third levels (such as collision>battery failure>tire pressure loss), the short message sending priority can be adjusted.

[0081] The above design summarizes the possible fault types of the vehicle, classifies different faults according to the vehicle damage and the degree of harm to personnel caused by different faults, and can adjust the short message sending priority when using the automatic trigger control mode configured in the vehicle to send short messages. When the rescue platform receives the information, it can directly confirm the severity of the vehicle fault, so as to use extremely priority resources to generate the optimal rescue plan.

[0082] Embodiment 4:

[0083] Based on Embodiment 1, this embodiment introduces a short message compression scheme. When the generated short message is compressed into a data packet and uploaded to the Beidou satellite, in the form of a dynamic message compression algorithm, the volume of the data packet is optimized to the single transmission capacity of the Beidou short message and supports extended fields;

[0084] Among them, the dynamic message compression algorithm can use the LZMA algorithm including three coding forms: dictionary coding, Huffman coding, and arithmetic coding;

[0085] Among them, in dictionary coding:

[0086] LZMA uses a sliding window as a dictionary. Assuming the window size is W, during the compression process, it will search for the longest phrase that matches the current data to be compressed within this window;

[0087] Let the current character sequence to be compressed be S, the longest matching phrase found in the window be P, its length be L, and the position of the phrase in the window be D (the offset from the current position). Then this match can be represented by the triple (D, L, C) (C is the single character remaining after the match);

[0088] Based on Huffman coding:

[0089] For the result after dictionary coding, that is, information such as (D, L, C), Huffman coding is used for further compression. Huffman coding constructs a Huffman tree according to the frequency of character occurrence. Characters with high frequencies have short codes, and characters with low frequencies have long codes, as follows:

[0090] Let the character be x i The frequency of occurrence is f(x i ), and its Huffman coding length is l(x i ), then the average code length L of the compressed data avg =∑i f(x i ) * l(x i ), by constructing a Huffman tree, minimize L avg to the minimum;

[0091] In arithmetic coding:

[0092] Map the probability distribution of the entire message to a real number interval [0, 1], and represent the message by continuously subdividing this interval;

[0093] Suppose the message consists of characters x1, x2,..., x n and their probabilities are p(x1), p(x2),..., p(x n ). Initially, the interval is [L0, R0) = [0, 1). For the first character x1, the new interval becomes [L1, R1) = [L0, L0 + p(x1) * (R0 - L0)). And so on, for the i-th character x i , the interval is updated to [L i , R i ) = [L i-1 , L i-1 + p(x i ) * (R i-1 - L i-1 ). Finally, select a suitable coding value in the interval [L n , R n ) to represent the entire message;

[0094] Meanwhile, an example of data encapsulation is as follows:

[0095]

[0096] The above design optimizes the volume of the data packet to the single - transmission capacity of Beidou short message (≤560 bits) by using the dynamic message compression algorithm, enabling vehicles in a fault state to summarize and compress the unique identifier of the vehicle, the precise location where the vehicle is located, the time when the vehicle breaks down, the specific faults that occur to the vehicle, and the associated faults that occur when the vehicle breaks down into short messages (compression of extended fields). This is conducive to completing the transmission of specific information through a small number of short messages and reducing the pressure of data transmission.

[0097] Finally, it should be noted that: Obviously, the above - mentioned embodiments are merely examples for clearly illustrating the present invention and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. An automotive emergency response message processing method based on Beidou short message, characterized in that including: S1: Real-time monitor whether vehicle failure or accident indicators occur; S2: Automatically trigger or manually trigger the generation of short messages used for communication under vehicle failure conditions; S3: Compress the generated short messages into data packets and upload them to Beidou satellites; S4: Send them to a preset rescue platform through the Beidou satellite communication module.

2. The vehicle emergency response message processing method based on Beidou short message as claimed in claim 1, wherein: including a vehicle status acquisition module, a Beidou short message communication module, a trigger control unit, and a message generation engine applied to this vehicle emergency response message processing method; Among them, the vehicle status acquisition module is used to real-time monitor faults such as collision sensors, airbag trigger signals, and abnormal battery voltages; The Beidou short message communication module is internally configured with a Beidou RDSS (Radio Determination Service) chip to support two-way communication; The trigger control unit includes an automatic trigger control and a manual trigger button; The message generation engine is used to compress vehicle VIN codes, GPS / Beidou dual-mode positioning data, fault codes, timestamps, etc. into data packets that conform to the Beidou short message format.

3. The method for processing automotive emergency response messages based on Beidou short messages according to claim 2, characterized in that: The automatic trigger control in the trigger control unit is controlled by an automatic trigger condition threshold, and the threshold formula for the automatic trigger condition is: Among them, is the average value of the monitoring index x (x is the number of fault factors such as collision sensors, airbag trigger signals, abnormal battery voltages, etc.) over a period of time; σ is the standard deviation of the monitoring index x within the same time period, which is used to measure the degree of data dispersion; k is a constant that can be adjusted according to specific circumstances, and it determines the deviation degree of the threshold relative to the average value.

4. The method for processing automotive emergency response messages based on Beidou short messages according to claim 2, wherein: The manual trigger button in the trigger control unit allows users to initiate a distress signal through the in-vehicle central control screen or the physical SOS button, and supports secondary confirmation to prevent mis-triggering.

5. A method for processing automotive emergency response messages based on Beidou short messages as claimed in claim 1, characterized in that: When the short message is transmitted to the preset rescue platform by the Beidou satellite communication module, the following formula is used to calculate the number of short message transmissions N within a certain time: where, T is the total time period; t is the time interval for each short message transmission; If the time interval for short message transmission is not fixed, or there are other limiting conditions, such as network latency, transmission success rate, etc., the actual number of transmissions may be less than the theoretical calculated number. Introduce a success rate factor p (0 < p ≤ 1), then the actual number of transmissions N 实际 = N * p.

6. The method for processing automotive emergency response messages based on Beidou short messages according to claim 1, characterized in that: The vehicle system in the monitoring state in S1 sets a fault level for vehicle faults, aggregates the existing faults of the vehicle into a set F, and divides the total fault set F into n1 categories according to the general nature or influence range of the faults, denoted as Satisfy And For the large class F in each first-level classification 1k (k = 1, 2,..., n1), it is further subdivided into n2 small classes denoted as Satisfying And And so on for secondary classification, so as to support the work of adjusting the short message transmission priority.

7. The method for processing automotive emergency response messages based on Beidou short message as claimed in claim 1, wherein: In S3, the form of a dynamic message compression algorithm is adopted to optimize the data packet volume to the single transmission capacity of the Beidou short message and support extended fields.

8. The method for processing automotive emergency response messages based on Beidou short messages according to claim 7, characterized in that: The dynamic message compression algorithm can use the LZMA algorithm including three coding forms: dictionary coding, Huffman coding, and arithmetic coding; Among them, in dictionary coding, LZMA uses a sliding window as a dictionary. Assuming the window size is W, during the compression process, it will search for the longest phrase that matches the current data to be compressed within this window; Let the current character sequence to be compressed be S, the longest matching phrase found in the window be P, its length be L, and the position of the phrase in the window be D (the offset from the current position). Then this match can be represented by the triple (D, L, C) (C is the single character remaining after the match); The results after dictionary encoding, namely information such as (D, L, C), etc., are further compressed using Huffman coding. Huffman coding constructs a Huffman tree based on the frequencies of characters. Characters with high frequencies have short codes, and characters with low frequencies have long codes, as shown below: Let the character be x i The frequency of occurrence is f(x i ), and the Huffman coding length is l(x i ). Then the average code length L avg = ∑ i f(x i ) * l(x i ). By constructing the Huffman tree, L avg is minimized; In arithmetic coding, the probability distribution of the entire message is mapped to a real number interval [0, 1], and the message is represented by continuously subdividing this interval; Suppose the message consists of characters x1, x2, …, x n where the probabilities are p(x1), p(x2), …, p(x n ), respectively. Initially, the interval is [L0, R0) = [0, 1). For the first character x1, the new interval becomes [L1, R1) = [L0, L0 + p(x1)*(R0 - L0)). And so on, for the i-th character x i , the interval is updated to [L i , R i ) = [L i-1 , L i-1 + p(x i )*(R i-1 - L i-1 ). Finally, a suitable coding value is selected in the interval [L n , R n ) to represent the entire message. It should be noted that there seems to be an error in the original text where "L0p(x1)*(R0 - L0)" should probably be "L0 + p(x1)*(R0 - L0)" for the correct calculation of the new interval. The translation is based on the corrected understanding.

9. The method for processing automotive emergency response messages based on Beidou short messages according to claim 7, characterized in that: In S1, when the vehicle is in a fault state, Beidou / GPS dual-mode positioning is used. The dual-mode positioning device for implementing the dual-mode positioning method simultaneously receives the signals of Beidou satellites and GPS satellites, and through the built-in algorithms and processing mechanisms, automatically selects the optimal satellite combination for positioning calculation according to various factors such as signal quality, the number of satellites, and positioning accuracy.

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