An EDR device based automotive accident data recording system and method

Abstract

The application discloses an automobile accident data recording system and method based on an EDR device, relates to the technical field of data recording, and comprises a deployment module, which is used for determining vehicle information and deploying the EDR device, listening to CAN bus data and six-axis sensor data in real time as vehicle real-time data based on the EDR device, and cyclically caching the vehicle real-time data within a preset condition; and a triggering module, which is connected with the deployment module and is used for determining triggering conditions, and starting the EDR device to record event original data immediately when any triggering condition is met. The application can perform data traction and overlap through the storage folding guide point, form overlapping data, reasonably and effectively use the memory in the EDR device, possibly maximize the storage time length of the data under the condition of guaranteeing the most basic storage data, and provide more sufficient data for subsequent vehicle data analysis.

Description

Technical Field

[0001] This invention relates to the field of data recording technology, and specifically to a vehicle accident data recording system and method based on an EDR device. Background Technology

[0002] Current automotive EDR (Electronic Data Recording) systems generally adopt a fixed partition and static storage recording mode, storing real-time vehicle data within a certain time period. They continuously cycle and overwrite the real-time vehicle data within a certain time period according to a fixed pattern. This has obvious technical shortcomings in terms of onboard memory resource utilization, data storage duration, and the integrity of accident data retention. It cannot effectively use the device memory and cannot provide storage for real-time vehicle data for a longer period of time. Summary of the Invention

[0003] The purpose of this invention is to provide a vehicle accident data recording system and method based on EDR equipment to address the shortcomings in the prior art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a vehicle accident data recording system based on an EDR device, comprising: The deployment module is used to determine vehicle information and deploy EDR devices. Based on the EDR devices, it monitors CAN bus data and six-axis sensor data in real time as real-time vehicle data and caches the most recently preset real-time vehicle data in a loop. The triggering module, connected to the deployment module, is used to determine the triggering conditions. When any triggering condition is met, the EDR device is immediately started to record the raw event data. The diagnostic analysis module, connected to the trigger module, is used to connect to the diagnostic instrument via the OBD interface of the EDR device, perform UDS access, download event data and generate an EDR event data reading report, and perform fault diagnosis based on the EDR event data reading report.

[0005] In a preferred embodiment, the deployment module includes: The information determination unit is used to determine vehicle information, install and connect the EDR equipment according to the vehicle information, and complete the deployment of the EDR equipment. The data acquisition unit listens to CAN bus data and six-axis sensor data through EDR device during vehicle operation as real-time vehicle data. The real-time vehicle data includes bus data, sensor data and corresponding timestamps. The caching unit is used to store real-time vehicle data in the EDR device, overwrite real-time vehicle data that exceeds preset conditions, and complete the cyclic caching of real-time vehicle data.

[0006] In a preferred embodiment, the cache unit includes: The configuration unit is used to configure multiple storage folding points for the temporary memory of the corresponding EDR device, wherein the number of storage folding points is the same as the number of data types in the real-time vehicle data; The storage management unit is used to receive real-time vehicle data of the corresponding data type at each storage fold point, and to manage the storage of the received real-time vehicle data of the corresponding data type through the storage fold points. The loop unit is used to overwrite the real-time vehicle data that exceeds the preset conditions from the beginning according to the timestamp, thus completing the loop caching of real-time vehicle data.

[0007] In a preferred embodiment, the configuration unit further includes: The first connection unit is used to configure multiple docking points and multiple receiving points for the temporary memory of the corresponding EDR device. The multiple docking points and multiple receiving points are connected one-to-one to obtain multiple storage folding points. The second connection unit is used to configure the connection time node for multiple storage folding points; The third connection unit is used to connect the docking point to the temporary memory, connect the receiving point to the connection receiving end of the EDR device, and connect the time node to both the temporary memory and the connection receiving end of the EDR device.

[0008] In a preferred embodiment, the storage management unit includes: The acquisition unit is used to receive real-time vehicle data of the corresponding data type from the connected receiver of the EDR device through the receiving point as vehicle type data. The management unit is used to determine whether the current vehicle type data is the same as the vehicle type data collected in the previous snapshot through the receiving point. If they are the same, the receiving point will notify the docking point, and the docking point will bind the vehicle type data of the previous snapshot stored in the temporary memory with the current timestamp. If they are different, the receiving point will bind the currently collected vehicle type data with the current timestamp and store it in the temporary memory. The overlapping unit is used to set the update frequency. The docking point overlaps the same vehicle type data in the temporary memory according to the update frequency to obtain overlapping data. Specifically, the storage address of the most recent timestamp of the same vehicle type data in the temporary memory is used as the overlapping address. The vehicle type data corresponding to the past timestamps and the bound timestamp data are transferred to the overlapping address to obtain overlapping data of a single vehicle type data corresponding to multiple timestamps.

[0009] In a preferred embodiment, the loop unit includes: The deletion unit is used to delete real-time vehicle data in the temporary memory after the maximum amount of data stored under preset conditions is reached, according to the timestamp from the oldest to the newest. The specific deletion steps are as follows: when deleting vehicle type data that forms overlapping data based on the timestamp from the oldest to the newest, the timestamp is deleted first according to the time process until the entire overlapping data is deleted, and then the real-time vehicle data is deleted. The overlay unit is used to overwrite the released temporary memory space with new real-time vehicle data, thus completing the circular caching of real-time vehicle data.

[0010] In a preferred embodiment, the triggering module includes: The defining unit is used to determine the triggering conditions, which include emergency deceleration triggering, final stop triggering, and safety system triggering. The recording unit is used to immediately start the dedicated memory in the EDR device to record the raw event data that triggered the trigger condition when any trigger condition is met.

[0011] In a preferred embodiment, the diagnostic analysis module includes: The docking unit is used to connect to the diagnostic instrument via the OBD interface of the EDR device after the triggering condition. The diagnostic instrument issues a 0x10 diagnostic session command and a 0x27 secure access command to execute UDS access. The UDS command reads the raw event data in the dedicated memory. The download diagnostic unit is used to download event data and generate an EDR event data read report, and to perform fault diagnosis based on the EDR event data read report.

[0012] The present invention also provides a method for recording vehicle accident data based on an EDR device, comprising the following steps: The vehicle information is determined and the EDR device is deployed. The EDR device is used to monitor CAN bus data and six-axis sensor data in real time as the vehicle's real-time data, and the vehicle's real-time data within the most recent preset conditions is cached in a loop. Determine the triggering conditions; when any triggering condition is met, immediately start the EDR device to record the raw event data. Connect the diagnostic instrument via the OBD interface of the EDR device, perform UDS access, download event data and generate an EDR event data reading report, and perform fault diagnosis based on the EDR event data reading report.

[0013] The technical effects and advantages provided by the present invention in the above technical solution are as follows: This invention enables data to be traction-overlapped by storing folding leads, forming overlapping data. This allows for the rational and effective use of the memory in the EDR device, maximizing the storage time of data while ensuring the most basic data storage, and providing more comprehensive data for subsequent vehicle data analysis. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0015] Figure 1 This is a system block diagram of the present invention.

[0016] Figure 2 This is a flowchart of the method of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0018] Example 1, please refer to Figure 1 As shown in this embodiment, a vehicle accident data recording system based on an EDR device includes: The deployment module is used to determine vehicle information and deploy EDR devices. Based on the EDR devices, it monitors CAN bus data and six-axis sensor data in real time as real-time vehicle data and caches the most recently preset real-time vehicle data in a loop. The triggering module, connected to the deployment module, is used to determine the triggering conditions. When any triggering condition is met, the EDR device is immediately started to record the raw event data. The diagnostic analysis module, connected to the trigger module, is used to connect to the diagnostic instrument via the OBD interface of the EDR device, perform UDS access, download event data and generate an EDR event data reading report, and perform fault diagnosis based on the EDR event data reading report.

[0019] In one embodiment, the deployment module includes: The information determination unit is used to determine vehicle information, install and connect the EDR equipment according to the vehicle information, and complete the deployment of the EDR equipment. The data acquisition unit listens to CAN bus data and six-axis sensor data through EDR device during vehicle operation as real-time vehicle data. The real-time vehicle data includes bus data, sensor data and corresponding timestamps. The caching unit is used to store real-time vehicle data in the EDR device, overwrite real-time vehicle data that exceeds preset conditions, and complete the cyclic caching of real-time vehicle data.

[0020] It should be noted that, firstly, the vehicle model must be confirmed, and information security must meet R155 / R156 standards; components must be E-MARK certified as vehicle information. The operating voltage, operating temperature, protection, and storage of the EDR device must be determined. Next, the sensor must be determined: a six-axis gyroscope (±16g, ±2048° / s); power-off recovery time: 10 seconds. Vehicle network planning should be implemented, with 4 CAN bus connections (powertrain / chassis / body / diagnostics), reserving an independent reading bus to avoid interfering with the overall vehicle network. The OBD interface should be connected to the EDR diagnostic CAN for UDS reading. Location selection: near the driver's cab / B-pillar, or in a rigid steel structure within the electrical cabinet for horizontal installation in areas with high structural integrity. EDR device orientation specifications: EDR housing XY plane∥vehicle horizontal plane, YZ plane⊥vehicle longitudinal plane, connector facing right, perpendicular to the front of the vehicle. Angle deviation: yaw / roll / pitch angles must be considered to ensure acceleration acquisition accuracy. Fixing method: screw fixing, vibration-resistant and anti-fall-off. Wiring and debugging are then performed. The vehicle is placed horizontally and stationary for zero-point calibration to eliminate installation angle errors. X / Y / Z axes are confirmed to be aligned with the vehicle coordinate system, and acceleration / angular velocity ranges are matched (±16g, ±2048° / s). Trigger thresholds are configured (according to the document trigger conditions): Rapid deceleration trigger: longitudinal deceleration > 3.25m / s², duration ≥ 0.7s. Final stop trigger: vehicle speed = 0, e.g., duration 20s (preset time period) or brake activation / engine shutdown. Safety system triggers: airbag / SOS / pretensioners (permanently locked, cannot be overridden), ABS / AEB / ESC (can be overridden). Speed: Acquisition of preset conditions before and after the event, 4Hz sampling. Acceleration: High-frequency sampling of X / Y axes for collision intensity / direction analysis. Synchronous recording: gear position, accelerator pedal, steering wheel angle, safety system status (airbag / ABS / AEB / ESC), timestamp; the above content includes bus data and sensor data. While the vehicle is in motion, EDR monitors CAN bus data and six-axis sensor data in real time, and continuously caches the most recently preset condition data. Low-power operation, without affecting the vehicle's power supply. Recording begins immediately upon fulfillment of any trigger condition: pre-trigger and post-trigger preset conditions are locked and written to the EDR device's memory. Airbag / SOS trigger: permanently locked, cannot be overwritten; ordinary events (ABS / AEB): can be overwritten by subsequent events. Power failure protection: after a collision power failure, the built-in power supply maintains a certain time, e.g., 10 seconds, to complete data writing and prevent data loss.

[0021] In one embodiment, the cache unit includes: The configuration unit is used to configure multiple storage folding points for the temporary memory of the corresponding EDR device, wherein the number of storage folding points is the same as the number of data types in the real-time vehicle data; The storage management unit is used to receive real-time vehicle data of the corresponding data type at each storage fold point, and to manage the storage of the received real-time vehicle data of the corresponding data type through the storage fold points. The loop unit is used to overwrite the real-time vehicle data that exceeds the preset conditions from the beginning according to the timestamp, thus completing the loop caching of the real-time vehicle data (the preset conditions here are the maximum amount of data that can be stored in the temporary memory. When storing real-time vehicle data, the data will only be overwritten according to the timestamp from the oldest to the newest when the preset conditions are exceeded).

[0022] In one embodiment, the configuration unit further includes: The first connection unit is used to configure multiple docking points and multiple receiving points for the temporary memory of the corresponding EDR device. The multiple docking points and multiple receiving points are connected one-to-one to obtain multiple storage folding points. The second connection unit is used to configure the connection time node for multiple storage folding points; The third connection unit is used to connect the docking point to the temporary memory, connect the receiving point to the connection receiving end of the EDR device, and connect the time node to both the temporary memory and the connection receiving end of the EDR device.

[0023] In one embodiment, the storage management unit includes: The acquisition unit is used to receive real-time vehicle data of the corresponding data type from the connected receiver of the EDR device through the receiving point as vehicle type data. The management unit is used to determine whether the current vehicle type data is the same as the vehicle type data collected in the previous snapshot through the receiving point. If they are the same, the receiving point will notify the docking point, and the docking point will bind the vehicle type data of the previous snapshot stored in the temporary memory with the current timestamp. If they are different, the receiving point will bind the currently collected vehicle type data with the current timestamp and store it in the temporary memory. The overlapping unit is used to set the update frequency. The docking point overlaps the same vehicle type data in the temporary memory according to the update frequency to obtain overlapping data. Specifically, the storage address of the most recent timestamp of the same vehicle type data in the temporary memory is used as the overlapping address. The vehicle type data corresponding to the past timestamps and the bound timestamp data are transferred to the overlapping address to obtain overlapping data of a single vehicle type data corresponding to multiple timestamps.

[0024] In one embodiment, the loop unit includes: The deletion unit is used to delete real-time vehicle data in the temporary memory after the maximum amount of data stored under preset conditions is reached, according to the timestamp from the oldest to the newest. The specific deletion steps are as follows: when deleting vehicle type data that forms overlapping data based on the timestamp from the oldest to the newest, the timestamp is deleted first according to the time process until the entire overlapping data is deleted, and then the real-time vehicle data is deleted. The overlay unit is used to overwrite the released temporary memory space with new real-time vehicle data, thus completing the circular caching of real-time vehicle data.

[0025] It should be noted that the EDR device is divided into temporary memory and dedicated memory. Temporary memory is used to store real-time vehicle data corresponding to ordinary events, for temporary storage and cyclical data overwriting. Dedicated memory is used to store real-time vehicle data triggered by sudden deceleration, final stop, and safety system triggers. Real-time vehicle data is collected cyclically in the temporary memory, so the amount of data stored is limited. To maximize the duration of stored real-time vehicle data, multiple docking points and multiple receiving points are configured for the temporary memory of the EDR device. These docking points and receiving points are data transmission ports with limited storage space. Multiple docking points and multiple receiving points are connected one-to-one to obtain multiple storage folding points. In addition, multiple storage folding points are configured to connect to time nodes. These time nodes are also data transmission ports with limited storage space. The time nodes are data transmission ports that store timestamps. The docking points are connected to the temporary memory, and the receiving points are connected to the receiving end of the EDR device. The time nodes are also connected to both the temporary memory and the receiving end of the EDR device, completing the connection between the data transmission ports.The EDR device connects to the vehicle and receives real-time vehicle data of the corresponding data type from the connected receiver of the EDR device as vehicle type data. The connected receiver of the EDR device categorizes the data according to data type and sends it to the corresponding receiving point. Each receiving point temporarily stores the vehicle type data collected in the previous frame. The receiving point checks if the current vehicle type data is the same as the vehicle type data collected in the previous frame. If they are the same, the receiving point notifies the docking point. The docking point binds the vehicle type data of the previous frame stored in its temporary memory with the current timestamp. In this case, the receiving point does not need to transmit the vehicle type data to the docking point; the receiving point still maintains the temporary storage of the vehicle type data collected in the previous frame for comparison with the vehicle type data collected in the next frame. If they are different, the receiving point binds the currently collected vehicle type data with the current timestamp and stores it in temporary memory. For example, if the vehicle has been moving for 5 seconds... If the speed is consistently 100 km / h, then there's no need to repeatedly store this data. Data overlap is achieved, and an update frequency can be set. The docking point overlaps the same vehicle type data in temporary memory according to this frequency. The storage address of the most recent timestamp of the same vehicle type data in temporary memory is used as the overlap address. Vehicle type data corresponding to past timestamps, along with their associated timestamps, are transferred to the overlap address. This results in overlapping data where a single vehicle type data point is bound to multiple timestamps. For example, if the current speed is 120 km / h, the previous speed was 119 km / h, but it was 120 km / h 10 seconds ago, the 120 km / h data from the previous 10 seconds can be transferred to the current overlap address. The current timestamp corresponds to the storage address of the most recent timestamp. Therefore, a single 120 km / h data point can be bound to multiple timestamps for storage, effectively utilizing temporary memory and allowing for the storage of more long-term real-time vehicle data.After the real-time vehicle data in the temporary memory reaches the maximum storage capacity set by a preset condition, the real-time vehicle data is deleted according to the timestamp from oldest to newest. The specific deletion steps are as follows: When deleting vehicle type data that forms overlapping data based on timestamps, the timestamps are deleted first according to the time sequence until all overlapping data is deleted. Then, the real-time vehicle data is deleted. For example, if data for 120km / h is bound to multiple timestamps when the preset condition is met, and it is necessary to delete data bound to 120km / h according to the time sequence, the timestamp corresponding to 120km / h needs to be deleted sequentially. When deleting data bound to the latest timestamp of 120km / h, then the latest timestamp is also deleted. The 20km / h data, along with its latest and final timestamp, is deleted together. During deletion, temporary memory is continuously released. For example, even when all vehicle type data is different, at least 20 seconds of real-time vehicle data can be stored. If data of the same vehicle type can overlap, the storage duration of the real-time vehicle data will be extended, making the most efficient use of temporary memory. While ensuring the basic 20 seconds of real-time vehicle data is stored cyclically, the storage duration is extended to provide more data for subsequent vehicle fault analysis. New real-time vehicle data overwrites the released temporary memory space, completing the cyclic caching of real-time vehicle data. By using storage folding points, data can be pulled and overlapped to form overlapping data, enabling reasonable and effective use of the memory in the EDR device. This maximizes the storage duration while ensuring the most basic data storage, providing more comprehensive data for subsequent vehicle data analysis.

[0026] In one embodiment, the triggering module includes: The defining unit is used to determine the triggering conditions, which include emergency deceleration triggering, final stop triggering, and safety system triggering. The recording unit is used to immediately start the dedicated memory in the EDR device to record the raw event data that triggered the trigger condition when any trigger condition is met.

[0027] It should be noted that the trigger threshold configuration (according to the document trigger conditions) includes: Rapid deceleration trigger: longitudinal deceleration > 3.25m / s², lasting ≥ 0.7s. Final stop trigger: vehicle speed = 0, continuous preset conditions or braking activation / engine shutdown (the maximum data storage capacity of temporary memory can store at least 20s of real-time vehicle data even when the real-time vehicle data is different at each moment. If the real-time vehicle data has the same condition, it can be processed according to the overlapping unit to obtain overlapping data, reducing the data storage memory used by temporary memory, and can store more than 20s of real-time vehicle data). The real-time vehicle data that meets the trigger conditions is transferred and stored in dedicated memory. The airbag / SOS / pretensioner (permanently locked, cannot be overwritten) is also stored in dedicated memory.

[0028] In one embodiment, the diagnostic analysis module includes: The docking unit is used to connect to the diagnostic instrument via the OBD interface of the EDR device after the triggering condition. The diagnostic instrument issues a 0x10 diagnostic session command and a 0x27 secure access command to execute UDS access. The UDS command reads the raw event data in the dedicated memory. The download diagnostic unit is used to download event data and generate an EDR event data read report, and to perform fault diagnosis based on the EDR event data read report.

[0029] It should be noted that the vehicle preprocessing and hardware wiring are as follows: With the vehicle in ACC / ON position, connect the diagnostic tool's OBD connector to the vehicle's 16-pin OBD diagnostic interface (pins 6-CAN_H, 14-CAN_L, 16 constant power), confirm stable power supply, and establish a physical link. UDS Diagnostic Handshake and Security Access Unlock (ISO14229): The diagnostic tool issues a 0x10 diagnostic session command to enter the EDR extended diagnostic session; it then issues a 0x27 secure access command to request seed-key response to unlock EDR flash memory read permissions (the airbag lock partition must be securely unlocked). UDS commands read raw event data from the NOR Flash: Using the 0x22 (ReadDataByIdentifier) ​​EDR-specific DID, data is read in segments from the Flash partition storage: raw binary data from the ordinary event partition and the airbag lock protection partition. The data is loaded from Flash into the EDR's on-chip RAM and then uploaded to the diagnostic tool. The diagnostic tool analyzes raw data and automatically generates EDR event reports: it analyzes time-series data such as timestamps, vehicle speed, acceleration, braking, and airbag status to generate standardized EDR read reports (including ΔV curves and event time-series tables). Based on the EDR reports, vehicle fault / accident diagnosis is performed: by comparing the time-series data in the report with vehicle fault codes and actual vehicle condition, the causes of airbag, braking, and electronic control system faults are located, and fault determination is completed.

[0030] Example 2, please refer to Figure 2As shown in this embodiment, a method for recording vehicle accident data based on an EDR device includes the following steps: S1. Determine vehicle information and deploy EDR equipment. Based on the EDR equipment, monitor CAN bus data and six-axis sensor data in real time as real-time vehicle data, and continuously cache the most recently preset real-time vehicle data. S2. Determine the triggering conditions. When any triggering condition is met, immediately start the EDR device to record the raw event data. S3. Connect the diagnostic instrument through the OBD interface of the EDR device, perform UDS access, download event data and generate an EDR event data reading report, and perform fault diagnosis based on the EDR event data reading report.

[0031] By storing folding leads, data can be traction-overlapped to form overlapping data, which enables reasonable and effective use of the memory in the EDR device. It can maximize the storage time of data while ensuring the most basic storage data, and provide more comprehensive data for subsequent vehicle data analysis.

[0032] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A vehicle accident data recording system based on an EDR device, characterized in that, include: The deployment module is used to determine vehicle information and deploy EDR devices. Based on the EDR devices, it monitors CAN bus data and six-axis sensor data in real time as real-time vehicle data and caches the most recently preset real-time vehicle data in a loop. The triggering module, connected to the deployment module, is used to determine the triggering conditions. When any triggering condition is met, the EDR device is immediately started to record the raw event data. The diagnostic analysis module, connected to the trigger module, is used to connect to the diagnostic instrument via the OBD interface of the EDR device, perform UDS access, download event data and generate an EDR event data reading report, and perform fault diagnosis based on the EDR event data reading report.

2. The vehicle accident data recording system based on an EDR device according to claim 1, characterized in that, The deployment module includes: The information determination unit is used to determine vehicle information, install and connect the EDR equipment according to the vehicle information, and complete the deployment of the EDR equipment. The data acquisition unit listens to CAN bus data and six-axis sensor data through EDR device during vehicle operation as real-time vehicle data. The real-time vehicle data includes bus data, sensor data and corresponding timestamps. The caching unit is used to store real-time vehicle data in the EDR device, overwrite real-time vehicle data that exceeds preset conditions, and complete the cyclic caching of real-time vehicle data.

3. A vehicle accident data recording system based on an EDR device according to claim 2, characterized in that, The cache unit includes: The configuration unit is used to configure multiple storage folding points for the temporary memory of the corresponding EDR device, wherein the number of storage folding points is the same as the number of data types in the real-time vehicle data; The storage management unit is used to receive real-time vehicle data of the corresponding data type at each storage fold point, and to manage the storage of the received real-time vehicle data of the corresponding data type through the storage fold points. The loop unit is used to overwrite the real-time vehicle data that exceeds the preset conditions from the beginning according to the timestamp, thus completing the loop caching of real-time vehicle data.

4. A vehicle accident data recording system based on an EDR device according to claim 3, characterized in that, The configuration unit further includes: The first connection unit is used to configure multiple docking points and multiple receiving points for the temporary memory of the corresponding EDR device. The multiple docking points and multiple receiving points are connected one-to-one to obtain multiple storage folding points. The second connection unit is used to configure connection time nodes for multiple storage folding points; The third connection unit is used to connect the docking point to the temporary memory, connect the receiving point to the connection receiving end of the EDR device, and connect the time node to both the temporary memory and the connection receiving end of the EDR device.

5. A vehicle accident data recording system based on an EDR device according to claim 4, characterized in that, The storage management unit includes: The acquisition unit is used to receive real-time vehicle data of the corresponding data type from the connected receiver of the EDR device through the receiving point as vehicle type data. The management unit is used to determine whether the current vehicle type data is the same as the vehicle type data collected in the previous snapshot through the receiving point. If they are the same, the receiving point will notify the docking point, and the docking point will bind the vehicle type data of the previous snapshot stored in the temporary memory with the current timestamp. If they are different, the receiving point will bind the currently collected vehicle type data with the current timestamp and store it in the temporary memory. The overlapping unit is used to set the update frequency. The docking point overlaps the same vehicle type data in the temporary memory according to the update frequency to obtain overlapping data. Specifically, the storage address of the most recent timestamp of the same vehicle type data in the temporary memory is used as the overlapping address. The vehicle type data corresponding to the past timestamps and the bound timestamp data are transferred to the overlapping address to obtain overlapping data of a single vehicle type data corresponding to multiple timestamps.

6. A vehicle accident data recording system based on an EDR device according to claim 5, characterized in that, The loop unit includes: The deletion unit is used to delete real-time vehicle data in the temporary memory after the maximum amount of data stored under preset conditions is reached, according to the timestamp from the oldest to the newest. The specific deletion steps are as follows: when deleting vehicle type data that forms overlapping data based on the timestamp from the oldest to the newest, the timestamp is deleted first according to the time process until the entire overlapping data is deleted, and then the real-time vehicle data is deleted. The overlay unit is used to overwrite the released temporary memory space with new real-time vehicle data, thus completing the circular caching of real-time vehicle data.

7. A vehicle accident data recording system based on an EDR device according to claim 1, characterized in that, The triggering module includes: The defining unit is used to determine the triggering conditions, which include emergency deceleration triggering, final stop triggering, and safety system triggering. The recording unit is used to immediately start the dedicated memory in the EDR device to record the raw event data that triggered the trigger condition when any trigger condition is met.

8. A vehicle accident data recording system based on an EDR device according to claim 1, characterized in that, The diagnostic analysis module includes: The docking unit is used to connect to the diagnostic instrument via the OBD interface of the EDR device after the triggering condition. The diagnostic instrument issues a 0x10 diagnostic session command and a 0x27 secure access command to execute UDS access. The UDS command reads the raw event data in the dedicated memory. The download diagnostic unit is used to download event data and generate an EDR event data read report, and to perform fault diagnosis based on the EDR event data read report.

9. A method for recording vehicle accident data based on an EDR device, used to implement the vehicle accident data recording system based on an EDR device as described in any one of claims 1-8, characterized in that, Includes the following steps: The vehicle information is determined and the EDR device is deployed. The EDR device is used to monitor CAN bus data and six-axis sensor data in real time as the vehicle's real-time data, and the vehicle's real-time data within the most recent preset conditions is cached in a loop. Determine the triggering conditions; when any triggering condition is met, immediately start the EDR device to record the raw event data. Connect the diagnostic instrument via the OBD interface of the EDR device, perform UDS access, download event data and generate an EDR event data reading report, and perform fault diagnosis based on the EDR event data reading report.

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