A car-machine time calibration system and method based on vehicle-mounted central domain control and mobile phone Bluetooth communication

Abstract

The application discloses a vehicle-machine time calibration system and method based on vehicle-mounted central domain control and mobile phone Bluetooth communication, and comprises the following steps: obtaining mobile phone local time data by using a mobile phone terminal time calibration software, and encapsulating the mobile phone local time data into a standardized time data packet; after two-way identity authentication of the mobile phone terminal time calibration software and a vehicle-mounted Bluetooth communication unit is successful, the mobile phone terminal time calibration software transmits the standardized time data packet to a vehicle-mounted central domain controller through an optimized vehicle-mounted Bluetooth communication protocol; time data analysis is performed on the standardized time data packet received by the vehicle-mounted central domain controller to obtain standard time data, data integrity check is performed on the standard time data, the standard time data that passes the data integrity check is taken as a reference, time errors caused by vehicle-mounted real-time clock chip drift are corrected, modified standard time is obtained, and the vehicle-mounted central domain controller synchronizes the modified standard time to vehicle domain controllers.

Description

Technical Field

[0001] This invention relates to the field of in-vehicle Bluetooth communication, specifically to an in-vehicle time calibration system and method based on in-vehicle central domain control and mobile phone Bluetooth communication. Background Technology

[0002] The prior art related to this invention is as follows: Currently, the time calibration methods for in-vehicle terminals (vehicle infotainment systems) can be mainly divided into the following five categories, each with different technical principles and application scenarios: GPS / BeiDou satellite time synchronization calibration: The vehicle's infotainment system receives time signals broadcast by satellites through its built-in GPS / BeiDou module, analyzes the signals, and completes time synchronization calibration with millisecond-level accuracy. This method is widely used in vehicles with satellite positioning capabilities, especially suitable for long-distance driving scenarios. However, it is significantly affected by signal obstruction and cannot function properly in areas with weak satellite signals, such as underground parking garages, tunnels, and densely populated areas with tall buildings, resulting in calibration blind spots.

[0003] Mobile network / vehicle Ethernet time synchronization calibration: The vehicle's infotainment system connects to a Network Time Protocol (NTP) server via a 4G / 5G mobile network or vehicle Ethernet to obtain standard time and complete calibration, achieving accuracy down to the second level. This method relies on network coverage and cannot be performed in environments without a network. Furthermore, network transmission delays may lead to calibration errors, and there are also issues with data consumption (mobile network scenario) or wiring limitations (vehicle Ethernet scenario).

[0004] Manual calibration: Users manually set the time, time zone, and daylight saving time parameters through the vehicle's infotainment system interface, without relying on external devices or a network. This method is cumbersome, prone to time deviations due to user input errors, and cannot be automatically updated. Over time, the inherent drift of the vehicle's clock chip will cause cumulative errors, and the calibration accuracy depends entirely on manual operation.

[0005] The vehicle's clock chip operates on its own: The vehicle's infotainment system relies on a built-in real-time clock (RTC) chip to count time. The chip is powered by the vehicle's power supply and can maintain timekeeping through a backup battery after a power outage. However, the RTC chip has inherent time drift (the average daily drift is usually ±1 to 5 seconds), which will cause the time deviation to gradually increase with long-term use. Moreover, there is no automatic calibration mechanism, so it needs to be manually corrected periodically.

[0006] Existing simple Bluetooth-assisted calibration solutions: A few in-vehicle systems support receiving mobile phone time data via Bluetooth, but this is only a data transmission of a single module and is not deeply integrated with the vehicle's central domain control. It lacks a standardized time data verification mechanism, security encryption process, and cross-domain synchronization strategy, which can easily lead to problems such as data tampering, calibration failure, or time asynchrony between different domains of the vehicle system. In addition, it has poor compatibility and only supports pairing with specific brand mobile phones and vehicle systems.

[0007] The disadvantages of existing technologies are as follows: Based on the above analysis of existing technologies, the current in-vehicle time calibration method has the following core defects: Relying on external conditions, the applicable scenarios are limited: GPS / BeiDou timing is affected by signal blockage and cannot be used in scenarios such as underground garages and tunnels; network timing depends on network coverage and fails in environments without network; neither of these methods can meet the real-time calibration requirements in scenarios with "no satellites and no network".

[0008] Insufficient calibration accuracy and stability: Manual calibration is prone to human error and cannot cope with clock chip drift; network time synchronization has transmission delays, and calibration accuracy is affected by network quality; existing simple Bluetooth calibration lacks a data verification mechanism, which can easily lead to calibration deviations due to data transmission errors.

[0009] Lack of security and standardization: Existing Bluetooth calibration solutions lack identity authentication and data encryption mechanisms, making time data susceptible to tampering and posing a security risk of malicious alteration of vehicle time; furthermore, the lack of a unified interaction architecture and chaotic data transmission paths can easily lead to calibration failures.

[0010] Insufficient cross-domain collaboration capability: All domains of the vehicle system, including the cockpit domain, body domain, and powertrain domain, need a unified time base to ensure functional collaboration, such as log recording and event functions. The existing calibration method only updates the cockpit domain display time and does not achieve full-domain time synchronization, which can easily lead to cross-domain data timing disorder.

[0011] Cumbersome operation or poor compatibility: Manual calibration is inefficient and prone to errors; existing Bluetooth calibration solutions have poor compatibility, only support specific devices, and lack an automatic triggering mechanism, requiring users to manually start calibration, resulting in a poor user experience.

[0012] Imbalance between power consumption and practicality: GPS / BeiDou modules consume a lot of power when left on for extended periods, affecting the range of vehicles, especially new energy vehicles; network timing requires data traffic, increasing user costs, and cannot be used in scenarios with insufficient data traffic. Summary of the Invention

[0013] The purpose of this invention is to provide a vehicle-mounted time calibration system and method based on in-vehicle central domain control and mobile phone Bluetooth communication. This system and method solve the problem of in-vehicle time calibration in scenarios without satellite or network access, eliminating dependence on satellite signals and mobile networks, and achieving near-range, dependency-free time calibration around or inside the vehicle. It improves calibration accuracy and stability by constructing a time data verification mechanism to eliminate transmission and human errors, controlling calibration errors to within 1 second, while also addressing in-vehicle clock chip drift and enabling periodic automatic calibration. It addresses the security vulnerabilities of existing Bluetooth calibration by establishing a two-way authentication and data encryption system to prevent time data tampering and unauthorized access, meeting the automotive-grade safety requirements of ISO 26262 ASIL-B. It achieves full-domain time synchronization for the vehicle-mounted system, resolving cross-domain timing issues by scheduling time updates across domain controllers through central domain control, ensuring cross-domain functional consistency. It optimizes the calibration interaction experience by enabling automatic calibration without manual user operation, improving compatibility with different brands and systems of mobile phones, while controlling power consumption during calibration to avoid affecting vehicle range. It establishes a standardized BLE (Bluetooth Low Energy) standard. The Energy time calibration architecture standardizes data transmission processes and protocols, addresses the lack of standardization in existing simplified solutions, and improves calibration reliability and maintainability.

[0014] To achieve this objective, the present invention provides a vehicle-mounted time calibration system based on in-vehicle central domain control and mobile phone Bluetooth communication, comprising: The mobile time acquisition and encapsulation module is used to acquire local time data from the mobile phone using the mobile time calibration software when the vehicle time calibration is triggered, and encapsulate the local time data into a standardized time data packet. The mobile time calibration software and the vehicle Bluetooth communication unit automatically perform two-way authentication. After successful two-way authentication, the mobile time calibration software transmits the standardized time data packet to the vehicle central domain controller through the optimized vehicle Bluetooth communication protocol. The vehicle-mounted time calibration module is used to parse the standardized time data packets received by the vehicle-mounted central domain controller to obtain standard time data, perform data integrity verification on the standard time data, use the standard time data that has successfully passed the data integrity verification as a reference, correct the time error caused by the drift of the vehicle-mounted real-time clock chip, and obtain the corrected standard time. The vehicle-mounted central domain controller synchronizes the corrected standard time to each domain controller in the vehicle.

[0015] Furthermore, the optimized vehicle-mounted Bluetooth communication protocol is as follows: an adaptive frequency hopping algorithm is used among multiple preset channels for transmitting standardized time data packets to select a channel that meets the preset requirements for transmitting standardized time data packets, and a data redundancy transmission mechanism is adopted to reduce the packet loss rate during the transmission of standardized time data packets.

[0016] Furthermore, the method for encapsulating mobile phone local time data into a standardized time data packet includes: concatenating the mobile phone local time data and the unique identifier of the mobile phone device into a string in a set order, wherein the mobile phone local time data includes UTC time, local time zone, daylight saving time status, and timestamp data, and calculating a CRC-32 checksum based on the string; and encapsulating the UTC time, local time zone, daylight saving time status, timestamp data, the unique identifier of the mobile phone device, and the CRC-32 checksum into a JSON format to obtain a standardized time data packet.

[0017] Furthermore, the method for automatically performing two-way authentication between the mobile time calibration software and the vehicle-mounted Bluetooth communication unit includes: after the mobile time calibration software detects the vehicle-mounted Bluetooth signal, it automatically establishes a connection; the vehicle-mounted Bluetooth sends a randomly generated dynamic verification code and a unique identifier of the vehicle device; after the mobile time calibration software completes the security verification between the user and the mobile phone through biometric identification or password protection, it generates authentication response information based on the dynamic verification code and the unique identifier of the vehicle device sent by the vehicle-mounted Bluetooth, and sends the authentication response information and the unique identifier of the mobile device together to the vehicle-mounted Bluetooth; the vehicle-mounted Bluetooth verifies whether the authentication response information is correct to complete the two-way authentication.

[0018] Furthermore, the method of selecting a channel that meets the preset requirements for transmitting standardized time data packets using an adaptive frequency hopping algorithm among multiple preset channels for transmitting standardized time data packets includes: when the mobile phone time calibration software and the vehicle-mounted Bluetooth communication unit complete two-way authentication, the vehicle-mounted Bluetooth and the mobile phone time calibration software send test data packets to each other through multiple preset channels for transmitting standardized time data packets. The vehicle-mounted Bluetooth monitors the packet error rate and received signal strength of each channel, and selects the channel with a packet error rate less than a preset threshold and a received signal strength within a set range as the channel that meets the preset requirements. When transmitting standardized time data packets, each channel has a unique sequence number. A random frequency hopping sequence is generated based on the sequence number of the channel that meets the preset requirements, and the standardized time data packets are transmitted sequentially in the channel that meets the preset requirements based on the frequency modulation sequence.

[0019] Furthermore, the method of reducing the packet loss rate during the transmission of standardized time data packets by adopting a data redundancy transmission mechanism includes: after the mobile time calibration software and the vehicle Bluetooth communication unit complete two-way authentication, the mobile time calibration software sequentially sends multiple identical standardized time data packets. Each standardized time data packet is transmitted by hopping according to the frequency hopping sequence generated by the adaptive frequency hopping algorithm in a channel that meets the preset requirements. The vehicle Bluetooth sequentially receives the standardized time data packets and parses and verifies their integrity.

[0020] Furthermore, the standardized time data packets received by the vehicle central domain controller are parsed to obtain standard time data. The method for verifying the data integrity of the standard time data includes: the vehicle-mounted Bluetooth communication unit sequentially unpacks the received standardized time data to obtain the original fields of the mobile phone's local time data; the vehicle-mounted Bluetooth communication unit concatenates the mobile phone's local time data and the unique identifier of the mobile phone device into a string in a set order; recalculates the CRC-32 checksum based on the string; compares the original CRC-32 checksum field in the original field of the mobile phone's local time data with the recalculated CRC-32 checksum; when the two checksums are exactly the same, it indicates that the data integrity verification of the corresponding standard time data packet is successful; and the UTC time, local time zone, and daylight saving time status in the original field of the mobile phone's local time data corresponding to the corresponding standard time data packet are used as the standard time data.

[0021] Furthermore, using the standard time data that has successfully verified data integrity as a benchmark, the time error caused by the drift of the vehicle real-time clock chip is corrected to obtain the corrected standard time. The specific method is as follows: the difference between the timestamp of the most recent time calibration log recorded by the vehicle central domain controller and the timestamp of the standard time data that has successfully verified data integrity is taken as the drift time interval. The product of the drift time interval and the inherent drift coefficient of the vehicle real-time clock chip is taken as the total time drift value. The sum of the total time drift value and the timestamp of the standard time data that has successfully verified data integrity is taken as the calibrated standard time. After each time calibration is completed, the vehicle central domain controller will record a time calibration log. The most recent time calibration log is the time calibration log closest to the current calibration time.

[0022] Furthermore, a vehicle time calibration method based on vehicle central domain control and mobile phone Bluetooth communication according to the system includes: When the vehicle time calibration is triggered, the mobile time calibration software obtains the local time data of the mobile phone and encapsulates the local time data of the mobile phone into a standardized time data packet. The mobile time calibration software and the vehicle Bluetooth communication unit automatically perform two-way authentication. After successful two-way authentication, the mobile time calibration software transmits the standardized time data packet to the vehicle central domain controller through the optimized vehicle Bluetooth communication protocol. The standardized time data packets received by the vehicle central domain controller are parsed to obtain standard time data. The standard time data is then verified for data integrity. The standard time data that has successfully passed the data integrity verification is used as a reference to correct the time error caused by the drift of the vehicle real-time clock chip, resulting in the corrected standard time. The vehicle central domain controller then synchronizes the corrected standard time to each domain controller in the vehicle.

[0023] The beneficial effects of this invention are as follows: Addressing the issues of existing in-vehicle time calibration technologies heavily relying on satellite or network signals, leading to failure in signal-free environments such as underground parking lots and tunnels; cumbersome manual calibration prone to human error; the lack of security authentication and data verification mechanisms in existing Bluetooth-assisted solutions making them susceptible to tampering; and system timing chaos caused by time asynchrony among domain controllers, this invention utilizes a mobile phone as a high-precision, portable, and reliable time source. Upon automatic triggering such as vehicle startup, the mobile application acquires and encapsulates a standardized time data packet containing complete time zone information. A secure link is established through two-way authentication and encryption, and an optimized Bluetooth protocol employs an adaptive frequency hopping algorithm to actively avoid interference channels. Combined with a data redundancy transmission mechanism, the data is reliably transmitted to the vehicle's central domain controller. The vehicle terminal parses and verifies the data's integrity, then uses the preset drift coefficient of the RTC chip for intelligent error compensation to generate an accurate standard time. Finally, through SOA platform scheduling, the calibrated time is synchronized to all domain controllers in the vehicle, including the cockpit, body, and powertrain domains, all at once. The construction of a highly secure, reliable, and fully automated time calibration system that does not rely on external infrastructure not only completely solves the calibration problem in environments without satellites or networks, keeping calibration errors stably within extremely small ranges (e.g., less than 1 second), but also suppresses the accumulation of long-term time errors through chip drift correction. The automotive-grade secure communication design between the mobile application and the vehicle's Bluetooth communication unit effectively defends against unauthorized access and data tampering. Furthermore, the mechanism of writing the generated precise standard time into all domain controllers within the vehicle that require a time reference at once and simultaneously, as long as the time calibration process is successfully executed only once, eliminates cross-domain timing errors. At the same time, the Bluetooth Low Energy design and broad mobile phone compatibility bring users a smooth calibration experience. Attached Figure Description

[0024] Figure 1 This is a structural diagram of the BLE Bluetooth system of the present invention; Figure 2 This is a schematic diagram of the structure of the present invention. Detailed Implementation

[0025] 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 a part of the embodiments of the present invention, not all of them. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Example 1 like Figure 2 As shown, a vehicle-mounted time calibration system based on in-vehicle central domain control and mobile phone Bluetooth communication includes: The mobile time acquisition and encapsulation module is used to acquire local time data from the mobile phone using the mobile time calibration software when the vehicle time calibration is triggered, and encapsulate the local time data into a standardized time data packet. The mobile time calibration software and the vehicle Bluetooth communication unit automatically perform two-way authentication. After successful two-way authentication, the mobile time calibration software transmits the standardized time data packet to the vehicle central domain controller through the optimized vehicle Bluetooth communication protocol. The vehicle-mounted time calibration module is used to parse the standardized time data packets received by the vehicle-mounted central domain controller to obtain standard time data, perform data integrity verification on the standard time data, use the standard time data that has successfully passed the data integrity verification as a reference, correct the time error caused by the drift of the vehicle-mounted real-time clock chip, and obtain the corrected standard time. The vehicle-mounted central domain controller synchronizes the corrected standard time to each domain controller in the vehicle.

[0027] In some embodiments, the BLE Bluetooth system architecture of the present invention is as follows: Figure 1 As shown, the BLE Bluetooth system architecture consists of an in-vehicle central control unit (CCU), a mobile terminal (Phone), and peripheral devices such as Bluetooth speakers (BT Speakers). The CCU integrates a dedicated Bluetooth Low Energy communication module, EGT CCU BLE (EGT Central Control Unit Bluetooth Low Energy), and runs BT Services. This service establishes a bidirectional communication link with the mobile phone via the GATT protocol (Generic Attribute Profile) for phone status reporting and command transmission. The mobile phone runs Phone BTservices and Connectivity Apps, which interact via an API interface. This allows the mobile application to securely and in real-time exchange data with the CCU via Bluetooth services and further control peripheral devices such as the BT Speaker through the API.

[0028] In some embodiments, the calibration system of the present invention comprises three parts: an in-vehicle calibration system, a mobile phone calibration system, and a BLE communication protocol optimization module. The functions of each module are as follows: Vehicle-mounted calibration system Integrated into the Renesas R-Car M3 central domain control platform, it communicates with various domain controllers of the vehicle's infotainment system, such as the cockpit domain, body domain, and powertrain domain, and includes the following core units: BLE Communication Unit: Adopts Goodix GR5405BENE automotive-grade BLE5.3 chip, which is AEC-Q100 Grade 2 certified. It supports SPI interface connection with central domain controller chip and is equipped with dual ceramic antennas that can provide a gain of 2dBi, enabling short-range wireless communication with mobile phone, such as a communication distance of 0-50 meters, data transmission rate of up to 2Mbps, and sleep power consumption ≤1mA, balancing transmission performance and power consumption.

[0029] Time calibration unit: It has a built-in time parsing module, error correction module and clock synchronization module; the time parsing module is responsible for parsing the time data transmitted by the mobile phone, including UTC time, time zone, daylight saving time information and timestamp; the error correction module, in combination with the preset drift system of the vehicle RTC chip, compensates and corrects the parsed time; the clock synchronization module sends time synchronization commands to the domain controllers of the vehicle through the SOA architecture interface to achieve time unification across the entire domain.

[0030] Security Authentication Unit: Integrates the Infineon AURIX TC4D9 security encryption chip, which supports the AES-256 encryption algorithm, to achieve two-way identity authentication between the mobile terminal and the vehicle terminal (based on the device's unique identifier + dynamic verification code), encryption of time data transmission, and abnormal access interception operations such as identifying and blocking unauthorized device access, in compliance with ISO 26262 ASIL-B level security requirements.

[0031] Cross-domain collaboration unit: It interfaces with the central domain control SOA platform, and after receiving the time calibration command, it schedules the cockpit domain controller to update the vehicle display time, the body domain controller to synchronize the log time, and the power domain controller to update the calibration event sequence to ensure that the time base of each domain is consistent; at the same time, it records calibration logs including calibration time, mobile device identification, calibration error, etc., to facilitate subsequent fault diagnosis.

[0032] Automatic Trigger Unit: Presets multiple scenario calibration trigger conditions, including triggering when the vehicle starts, triggering when the BLE connection is established, triggering when the vehicle time deviates from the historical calibration time by more than 5 seconds, and triggering at a fixed time every day (such as 2 a.m.), without requiring manual operation by the user, thus achieving automated calibration.

[0033] The mobile calibration system is presented as an app that supports iOS 15.0+ and Android 12.0+, and its core components include: BLE connectivity module: Supports automatic search and matching of vehicle-mounted BLE devices, including the Goodix GR5405BENE chip. It adopts a fast pairing algorithm, which can achieve a pairing time of ≤3 seconds and automatically reconnect within 1 second after connection interruption. When the signal strength is lower than -70dBm, it switches to the backup antenna to ensure connection stability.

[0034] Time acquisition module: Real-time acquisition of high-precision local time on the mobile phone, i.e., synchronized with the mobile phone system time. This time has been accurately calibrated through the mobile network or satellite, including UTC time (Coordinated Universal Time), local time zone, daylight saving time status, and millisecond-level timestamp, ensuring the accuracy of the time data source.

[0035] Security verification module: Supports biometric identification methods such as fingerprint recognition and facial recognition. Time data can only be sent after successful verification. It also stores the unique identifier of the vehicle terminal device to achieve device matching during two-way identity authentication.

[0036] Data transmission module: Encapsulates time data in a standardized format (such as JSON format, including time information, device identifier, and check code), transmits it to the vehicle terminal via the optimized BLE protocol, and receives calibration result feedback from the vehicle terminal after transmission is completed, displaying calibration success or failure on the APP.

[0037] BLE communication protocol optimization module: To address the complex electromagnetic environment in vehicles, such as electromagnetic interference from engines and motors, the traditional BLE protocol is optimized to ensure stable time data transmission. Anti-interference optimization: Adaptive frequency hopping algorithm is adopted to dynamically avoid interference channels; time data adopts redundant transmission mechanism to reduce packet loss rate to below 0.1%.

[0038] Power consumption optimization: A dynamic power consumption adjustment strategy is adopted. After the calibration data transmission is completed, the BLE module immediately enters a sleep mode with power consumption ≤1mA and is only woken up when the calibration conditions are triggered, thereby reducing vehicle energy consumption.

[0039] Compatibility optimization: Supports multiple versions of BLE 5.0 / 5.1 / 5.2 / 5.3, adapting to BLE modules of different mobile phones; built-in data format adaptive conversion function ensures data interaction compatibility between mobile phones of different systems and the vehicle terminal.

[0040] In some embodiments, the time calibration process of the present invention includes five stages: triggering startup, connection authentication, data transmission, calibration execution, and result feedback, as detailed below: Triggered Startup: When preset triggering conditions such as vehicle startup are met, the vehicle terminal automatically triggers the calibration process, the BLE communication unit wakes up and enters a connectable state, and automatically searches for nearby paired mobile devices.

[0041] Connection Authentication: After the mobile APP detects the BLE signal from the vehicle, it automatically establishes a connection; both parties initiate two-way authentication. The vehicle sends a dynamic verification code, and the mobile APP returns the device identifier and verification code after passing the security verification. After successful authentication, a secure communication link is established (if authentication fails, the process terminates and the APP prompts "Authentication failed, unable to calibrate").

[0042] Data transmission: The mobile phone time acquisition module obtains the current high-precision time data, encapsulates it, and transmits it to the vehicle terminal through the optimized BLE protocol; after receiving the data, the vehicle terminal's security authentication unit decrypts and verifies the data integrity (checksum matching). If the verification passes, it enters the calibration process; if the verification fails, it requests the mobile phone to retransmit the data, with a maximum of 3 verification attempts.

[0043] Calibration execution: The on-board time calibration unit parses the time data, combines it with the RTC chip drift coefficient to correct errors, and generates the calibrated standard time; the cross-domain coordination unit schedules the controllers of each domain in the vehicle to update the time synchronously, and completes the full-domain time calibration; at the same time, the calibration log is recorded.

[0044] Feedback: The vehicle-mounted unit transmits the calibration results, including success or failure, calibration error, etc., to the mobile phone via BLE. The APP displays a calibration success message, such as the vehicle time being synchronized and the calibration error being 0.3 seconds. If the calibration fails, the specific reason is displayed, such as data transmission failure, please move closer to the vehicle and try again, etc.

[0045] In some technical solutions, the optimized vehicle-mounted Bluetooth communication protocol is as follows: an adaptive frequency hopping algorithm is used among multiple preset channels for transmitting standardized time data packets to select a channel that meets the preset requirements to transmit standardized time data packets, and a data redundancy transmission mechanism is used to reduce the packet loss rate during the transmission of standardized time data packets.

[0046] The data redundancy transmission mechanism transmits the same standardized time data packet multiple times in succession. This means that even if a data packet is lost at a very brief moment due to a sudden interference (which may occur in a channel during the frequency hopping process), its subsequent identical copy can still be successfully transmitted on other channels or at different times in the frequency hopping sequence. By increasing the number of transmission attempts, the probability of at least one data packet successfully arriving at the receiving end is significantly increased.

[0047] By actively avoiding interference channels through an adaptive frequency hopping algorithm and combining it with a data redundancy transmission mechanism, the transmission success rate and real-time performance of standardized time data packets in complex vehicle electromagnetic environments can be significantly improved, ensuring reliable reception and high-precision calibration of time synchronization signals.

[0048] In some technical solutions, the method of encapsulating mobile phone local time data into a standardized time data packet includes: concatenating the mobile phone local time data and the unique identifier of the mobile phone device into a string in a set order, wherein the mobile phone local time data includes UTC time, local time zone, daylight saving time status and timestamp data, and calculating a CRC-32 checksum based on the string; and encapsulating the UTC time, local time zone, daylight saving time status and timestamp data, the unique identifier of the mobile phone device and the CRC-32 checksum into JSON format to obtain a standardized time data packet.

[0049] In some embodiments, the encapsulation involves directly encapsulating data such as UTC time, local time zone, daylight saving time status, timestamp data, the unique identifier of the mobile device, and the calculated CRC-32 checksum into a JSON object according to a predefined key name structure (the key name structure includes top-level keys: timestamp, time_data, device_info, and checksum) to obtain a standardized time data packet. Encapsulating the standardized time data packet into a standardized JSON data packet achieves data format unification and interoperability, simplifies subsequent data processing and parsing, improves data transmission efficiency, and enhances the system's scalability and compatibility.

[0050] Through structured encapsulation and verification mechanisms, the integrity, accuracy, and parsability of time data during transmission are ensured. CRC-32 checksums effectively detect whether data packets have been tampered with or transmitted incorrectly; the JSON format provides a cross-platform, easily parsed standard data structure; and it includes complete time zone, daylight saving time information, and unique device identifiers, guaranteeing global consistency of time information and precise correspondence with data sources, providing reliable, processing-free standardized input for backend systems.

[0051] In some technical solutions, the method for automatic two-way authentication between mobile phone time calibration software and vehicle-mounted Bluetooth communication unit includes: after the mobile phone time calibration software detects the vehicle-mounted Bluetooth signal, it automatically establishes a connection; the vehicle-mounted Bluetooth sends a randomly generated dynamic verification code and a unique identifier of the vehicle device; after the mobile phone time calibration software completes the security verification between the user and the mobile phone through biometric identification or password protection, it generates authentication response information based on the dynamic verification code sent by the vehicle-mounted Bluetooth and the unique identifier of the vehicle device, and sends the authentication response information and the unique identifier of the mobile phone device together to the vehicle-mounted Bluetooth; the vehicle-mounted Bluetooth verifies whether the authentication response information is correct to complete the two-way authentication.

[0052] The two-way authentication method combines dynamic verification codes, unique device identifiers, and user biometrics to achieve dual verification of device and user identities. This effectively prevents man-in-the-middle attacks, device impersonation, and unauthorized access, establishing a highly reliable and secure initial link for subsequent time calibration and frequency hopping communication, ensuring that the entire communication process is under control from the outset.

[0053] In some technical solutions, an adaptive frequency hopping algorithm is used among multiple preset channels for transmitting standardized time data packets. The method for selecting a channel that meets preset requirements for transmitting standardized time data packets includes: when the mobile phone time calibration software and the vehicle-mounted Bluetooth communication unit complete two-way authentication, the vehicle-mounted Bluetooth and the mobile phone time calibration software send test data packets to each other through multiple preset channels for transmitting standardized time data packets. The vehicle-mounted Bluetooth monitors the packet error rate and received signal strength of each channel, and selects the channel with a packet error rate less than a preset threshold and a received signal strength within a set range as the channel that meets the preset requirements. When transmitting standardized time data packets, each channel has a unique sequence number. A random frequency hopping sequence is generated based on the sequence number of the channel that meets the preset requirements, and the standardized time data packets are transmitted sequentially in the channels that meet the preset requirements based on the frequency modulation sequence.

[0054] In some embodiments, the adaptive frequency hopping algorithm has 20 available channels with a frequency range of 2.4-2.48 GHz. The preset threshold for packet error rate (PER) can be set to PER≤30%, and the channels with received signal strength within a set range can be set to channels with received signal strength of -50 dBm to -80 dBm, but are not limited to those with received signal strength of -50 dBm to -80 dBm.

[0055] By combining prior channel quality assessment with dynamic frequency hopping, interference in the wireless environment can be proactively and intelligently avoided, rather than passively responding. In the initial stages of communication establishment, high-quality channels with low packet error rates and stable signal strength are selected through bidirectional testing, forming the foundation for reliable data transmission. During actual data transmission, a pseudo-random frequency hopping sequence is generated based on the high-quality channel sequence number, making the transmission path difficult to predict and track. This mechanism effectively combats co-channel interference and frequency-selective fading caused by WiFi, other Bluetooth devices, etc., thereby improving the reliability and stability of standardized time data packet transmission and ensuring high accuracy and robustness of the time synchronization process.

[0056] In some technical solutions, methods for reducing packet loss during the transmission of standardized time data packets by employing a data redundancy transmission mechanism include: after the mobile time calibration software and the vehicle-mounted Bluetooth communication unit complete two-way authentication, the mobile time calibration software sequentially sends multiple identical standardized time data packets. Each standardized time data packet is transmitted by hopping according to a frequency hopping sequence generated by an adaptive frequency hopping algorithm in a channel that meets preset requirements. The vehicle-mounted Bluetooth sequentially receives the standardized time data packets and parses and verifies their integrity.

[0057] The time data adopts a redundant transmission mechanism, that is, critical data is repeatedly transmitted two or more times to reduce the packet loss rate to below 0.1%.

[0058] By sequentially sending multiple identical data packet copies, packet loss or errors caused by random interference or sudden noise in a complex electromagnetic environment can be compensated for by other successfully transmitted copies, thereby significantly improving the transmission success rate and reliability of time calibration critical data. Each redundant data packet is transmitted independently on a pre-selected high-quality channel according to a frequency hopping sequence. Even if a channel experiences sudden interference during transmission, it will only affect the individual copies currently being transmitted on that channel, while other copies can still be transmitted in parallel or sequentially through other clean channels. This disperses transmission risks in both time and frequency dimensions, enhancing the system's robustness against frequency-selective fading and instantaneous strong interference.

[0059] In some technical solutions, the standard time data received by the vehicle central domain controller is parsed to obtain standard time data. The method for verifying the data integrity of the standard time data includes: the vehicle-mounted Bluetooth communication unit sequentially unpacks the received standard time data to obtain the original field of the mobile phone's local time data; the vehicle-mounted Bluetooth communication unit concatenates the mobile phone's local time data and the unique identifier of the mobile phone device into a string in a set order; the CRC-32 checksum is recalculated based on the string; the original field of the CRC-32 checksum in the original field of the mobile phone's local time data is compared with the recalculated CRC-32 checksum; when the two checksums are exactly the same, it indicates that the data integrity verification of the corresponding standard time data packet is successful; and the UTC time, local time zone, and daylight saving time status in the original field of the mobile phone's local time data corresponding to the corresponding standard time data packet are used as the standard time data.

[0060] By performing rigorous unpacking, field extraction, string concatenation, CRC-32 checksum recalculation, and comparison processes on the received standardized time data packets, a highly reliable data integrity verification barrier is established. This barrier can accurately identify and filter any bit errors, data tampering, or information corruption caused by factors such as channel interference, signal attenuation, or noise during wireless transmission, thus ensuring that only completely lossless time data consistent with the original content sent by the sender is adopted by the system. By using the successfully verified UTC time, local time zone, and daylight saving time status as the final standard time data, accurate data is provided for subsequent time correction and other processing, avoiding a chain reaction of system timing errors caused by the use of incorrect or damaged time data.

[0061] In some technical solutions, the standard time data that has successfully verified data integrity is used as a benchmark to correct the time error caused by the drift of the vehicle real-time clock chip. The specific method to obtain the corrected standard time is as follows: the difference between the timestamp of the most recent time calibration log recorded by the vehicle central domain controller and the timestamp of the standard time data that has successfully verified data integrity is taken as the drift time interval. The product of the drift time interval and the inherent drift coefficient of the vehicle real-time clock chip is taken as the total time drift value. The sum of the total time drift value and the timestamp of the standard time data that has successfully verified data integrity is taken as the calibrated standard time. After each time calibration is completed, the vehicle central domain controller will record a time calibration log. The most recent time calibration log is the time calibration log closest to the current calibration time.

[0062] By introducing a predictive compensation algorithm based on historical calibration records and the inherent drift model of the RTC chip, a one-time, absolute time coverage can be transformed into a continuous, autonomous error suppression system. This proactively corrects known hardware timing defects between two external calibrations, significantly improving the timekeeping accuracy of the vehicle system during periods without external time source dependence. By accurately calculating and compensating for the theoretical drift since the last successful calibration, this method effectively breaks the predicament of linear growth in time error caused by the inherent bias of the RTC chip accumulated over time. This ensures that even after long-term parking, the accumulated error of the vehicle clock can be controlled within a predictable and minimal range related to the drift coefficient and calibration cycle, rather than expanding indefinitely. This ensures that each correction is based on a verified accurate time starting point, avoiding error propagation.

[0063] In some embodiments, specific implementations of the present invention include: The hardware deployment is as follows: Vehicle-mounted hardware: The Renesas R-Car M3 central domain control platform, which supports integration of the cabin and control domains, is selected. It integrates the Goodix GR5405BENE BLE 5.3 chip with AEC-Q100 Grade 2 certification and connects to the central domain control main chip via the SPI interface. It is equipped with dual ceramic antennas that can provide a gain of 2dBi, which are installed on the inside of the windshield and the inside of the trunk respectively to achieve full vehicle signal coverage. It integrates the Infineon AURIX TC4D9 security encryption chip that supports SPI interface communication for data encryption and identity authentication. The controllers of various vehicle domains, such as the cabin domain, body domain, and power domain, communicate with the central domain control via the CANFD bus to receive time synchronization commands.

[0064] Mobile hardware: Supports smartphones with BLE 5.0 and above, such as iPhone 14 and above, Huawei Mate 60 and above, with biometric recognition functions such as fingerprint or facial recognition; The mobile phone system version must meet iOS 15.0 and above, Android 12.0 and above, to ensure the accuracy of time acquisition and APP compatibility.

[0065] The software configuration is as follows: The vehicle-mounted software is developed based on the QNX (QNX Neutrino Real-Time Operating System) real-time operating system, integrating a time calibration module, a security authentication module, a cross-domain collaboration module, and an automatic triggering module. The time calibration module uses a simplified version of the NTP (Network Time Protocol) time synchronization protocol, supports UTC time and local time zone conversion, and presets the RTC chip drift coefficient. The security authentication module incorporates the AES-256 encryption algorithm for data encryption and verification. The automatic triggering module allows adjustment of trigger conditions, such as calibration intervals and deviation thresholds, via configuration files. The cross-domain collaboration module interfaces with the SOA (Service-Oriented Architecture Platform) to call time synchronization service interfaces from various domains.

[0066] Mobile App Software: Utilizes the Flutter cross-platform development framework to achieve compatibility with iOS and Android systems; the BLE connection module integrates fast pairing and automatic reconnection algorithms; the time acquisition module calls the mobile system API to obtain high-precision time; the security verification module integrates a biometric SDK and a device identification management module; the data transmission module encapsulates time data in JSON format and adds a CRC-32 checksum to ensure data integrity.

[0067] BLE protocol optimization configuration: Adaptive frequency hopping algorithm sets 20 channels, dynamically avoiding interference channels based on vehicle electromagnetic environment detection; Time data transmission adopts a hybrid mode of BLE broadcast + connection to ensure real-time transmission; Dynamic power consumption adjustment strategy sets 3 power modes (sleep mode power consumption 1mA, Bluetooth connection mode power consumption 5mA, data transmission mode power consumption 10mA), and immediately switches to sleep mode after calibration.

[0068] The calibration process implementation details are as follows: Scenario 1: Driving Score Assessment and Display Taking vehicle start-up trigger calibration as an example: Triggered Startup: When the user starts the vehicle, the vehicle's central domain controller powers on and initializes, automatically triggering the time calibration process; it wakes up BLE communication units such as Goodix GR5405BENE, enters a connectable state, and sends a BLE broadcast signal containing the unique identifier of the vehicle device through the main antenna.

[0069] Connection Authentication: When a user enters the vehicle with their paired mobile phone or is within 10 meters of the vehicle, the mobile app automatically searches for the vehicle's BLE signal and initiates a connection request. After the BLE connection is established, the vehicle's security authentication unit generates a 6-digit dynamic verification code, which is transmitted to the mobile phone via BLE. The user completes facial recognition verification through the app, and the app sends the verification code and the mobile device identifier back to the vehicle. After the vehicle verifies that the verification code and device identifier match correctly, two-way identity authentication is completed, and a secure communication link is established. The entire process of establishing a secure communication link takes ≤5 seconds, demonstrating rapid response.

[0070] Data transmission: The mobile time acquisition module calls the system API to obtain the current time data, including UTC time: 2025-12-31 12:00:00.000, time zone: East 8, daylight saving time: off, timestamp: 1735684800000, and checksum. The data transmission module encapsulates the time data into JSON format and transmits it to the vehicle terminal via the optimized BLE protocol. After receiving the data, the vehicle terminal decrypts it and verifies the data integrity using a CRC-32 checksum. If the verification passes, it proceeds to the next step; if the verification fails, it requests a retransmission, with a maximum of 3 retries. If more than 3 retries are attempted, the Bluetooth connection is re-established.

[0071] Calibration Execution: The on-board time calibration unit parses time data and combines it with the RTC chip drift coefficient, which is preset to an average of +1 second per day. If 24 hours have passed since the last calibration, it is corrected by +1 second to generate the calibrated standard time, such as 2025-12-31 12:00:01.000. The cross-domain collaboration unit sends time synchronization commands to each domain controller through the SOA platform: the cockpit domain controller updates the time on the vehicle's display screen, the body domain controller synchronizes the time recorded in the log, and the powertrain domain controller calibrates the timing of motor control events. At the same time, it records calibration logs containing calibration time, mobile device identifier, original time, post-calibration time, and a calibration error of 0.3 seconds. The entire calibration process takes ≤2 seconds, with a fast response.

[0072] Feedback: The vehicle terminal transmits the calibration success result and error data to the mobile phone. The APP pops up a window to indicate that the vehicle time has been synchronized and calibrated with an error of 0.3 seconds, and the calibration log is also uploaded to the APP. Users can view historical calibration information in the APP calibration record.

[0073] Calibration implementation in other scenarios: (1) No network underground garage scenario: When a vehicle enters an underground garage, i.e., in an environment without satellite signal and network, if the time of the vehicle unit deviates from the historical calibration time by more than 5 seconds, calibration will be automatically triggered; when the user carries a mobile phone and approaches the vehicle at a distance of ≤5 meters, the APP and the vehicle terminal establish a connection through BLE to complete authentication and time transmission, thereby achieving calibration without network and a calibration error of ≤0.5 seconds.

[0074] Daily scheduled calibration scenario: Calibration is preset to be triggered at 2:00 AM every day. If the vehicle is in standby mode, the BLE module will wake up and search for the paired mobile phone. The mobile APP runs in the background and automatically completes the connection, authentication and time transmission. After calibration, the BLE module enters sleep mode. The power consumption is ≤5mAh throughout the process, which does not affect the vehicle's range.

[0075] Manually triggered calibration scenario: Users can manually initiate calibration via the manual calibration button on the mobile APP. After triggering, the process is the same as automatic calibration. It is suitable for emergency calibration needs when users discover time deviations in the vehicle system. The response time is ≤3 seconds.

[0076] The performance test results are as follows: The technical solution of this invention was tested on a real vehicle. The test vehicle was a new energy passenger vehicle equipped with Renesas R-Car M3 central domain control. The test results are as follows: Calibration accuracy: Under different scenarios, i.e., with or without satellite signal, with or without network, the time calibration error is ≤1 second, with an average error of 0.3 seconds, which meets the time accuracy requirements of the vehicle-mounted system.

[0077] Transmission stability: Under the electromagnetic environment of the vehicle, such as when the engine and motor are running, the data packet loss rate is 0.08%, the BLE connection success rate is 100%, and there are no calibration failure cases.

[0078] Power consumption: Single calibration power consumption ≤ 5mAh, daily timed calibration (including sleep mode) power consumption ≤ 10mAh, the impact on the range of new energy vehicles is negligible.

[0079] Compatibility: Adapted to 10 different mobile phone brands (iOS 15.0-17.0, Android 12.0-14.0), the calibration process is normal and the compatibility is good.

[0080] Security: Simulating unauthorized device access and data tampering attacks, the security authentication unit can identify and block them within 1 second. No calibration anomalies were observed, meeting the ISO 26262 ASIL-B level security requirements.

[0081] Calibration efficiency: The entire calibration process takes ≤7 seconds, automatically triggered without user intervention, providing an excellent interactive experience; cross-domain time synchronization delay is ≤0.5 seconds, and the time consistency of each domain controller is good.

[0082] Example 2 A vehicle time calibration method based on vehicle central domain control and mobile phone Bluetooth communication according to the system includes: When the vehicle time calibration is triggered, the mobile time calibration software obtains the local time data of the mobile phone and encapsulates the local time data of the mobile phone into a standardized time data packet. The mobile time calibration software and the vehicle Bluetooth communication unit automatically perform two-way authentication. After successful two-way authentication, the mobile time calibration software transmits the standardized time data packet to the vehicle central domain controller through the optimized vehicle Bluetooth communication protocol. The standardized time data packets received by the vehicle central domain controller are parsed to obtain standard time data. The standard time data is then verified for data integrity. The standard time data that has successfully passed the data integrity verification is used as a reference to correct the time error caused by the drift of the vehicle real-time clock chip, resulting in the corrected standard time. The vehicle central domain controller then synchronizes the corrected standard time to each domain controller in the vehicle.

[0083] Example 3 The present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the steps of the method described in Embodiment 2.

[0084] This invention can be implemented wholly or partially through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented wholly or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)).

[0085] Those skilled in the art will readily understand that the above are merely preferred embodiments of the present invention and do not limit the present invention. Any modifications, combinations, substitutions, improvements, etc., made under the spirit and principles of the present invention are included within the protection scope of the present invention.

[0086] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A vehicle-mounted time calibration system based on in-vehicle central domain control and mobile phone Bluetooth communication, characterized in that, It includes: The mobile time acquisition and encapsulation module is used to acquire local time data from the mobile phone using the mobile time calibration software when the vehicle time calibration is triggered, and encapsulate the local time data into a standardized time data packet. The mobile time calibration software and the vehicle Bluetooth communication unit automatically perform two-way authentication. After successful two-way authentication, the mobile time calibration software transmits the standardized time data packet to the vehicle central domain controller through the optimized vehicle Bluetooth communication protocol. The vehicle-mounted time calibration module is used to parse the standardized time data packets received by the vehicle-mounted central domain controller to obtain standard time data, perform data integrity verification on the standard time data, use the standard time data that has successfully passed the data integrity verification as a reference, correct the time error caused by the drift of the vehicle-mounted real-time clock chip, and obtain the corrected standard time. The vehicle-mounted central domain controller synchronizes the corrected standard time to each domain controller in the vehicle.

2. The vehicle time calibration system based on vehicle central domain control and mobile phone Bluetooth communication according to claim 1, characterized in that: The optimized vehicle-mounted Bluetooth communication protocol is as follows: an adaptive frequency hopping algorithm is used among multiple preset channels for transmitting standardized time data packets to select a channel that meets the preset requirements for transmitting standardized time data packets, and a data redundancy transmission mechanism is used to reduce the packet loss rate during the transmission of standardized time data packets.

3. The vehicle time calibration system based on vehicle central domain control and mobile phone Bluetooth communication according to claim 2, characterized in that: The method for encapsulating mobile phone local time data into a standardized time data packet includes: concatenating the mobile phone local time data and the unique identifier of the mobile phone device into a string in a predetermined order, wherein the mobile phone local time data includes UTC time, local time zone, daylight saving time status, and timestamp data, and calculating a CRC-32 checksum based on the string; and encapsulating the UTC time, local time zone, daylight saving time status, timestamp data, the unique identifier of the mobile phone device, and the CRC-32 checksum into a JSON format to obtain a standardized time data packet.

4. The vehicle time calibration system based on vehicle central domain control and mobile phone Bluetooth communication according to claim 1, characterized in that: The method for automatic two-way authentication between mobile time calibration software and vehicle-mounted Bluetooth communication unit includes: after the mobile time calibration software detects the vehicle-mounted Bluetooth signal, it automatically establishes a connection; the vehicle-mounted Bluetooth sends a randomly generated dynamic verification code and a unique identifier of the vehicle device; after the mobile time calibration software completes the security verification between the user and the mobile phone through biometric identification or password protection, it generates authentication response information based on the dynamic verification code sent by the vehicle-mounted Bluetooth and the unique identifier of the vehicle device, and sends the authentication response information and the unique identifier of the mobile device together to the vehicle-mounted Bluetooth; the vehicle-mounted Bluetooth verifies whether the authentication response information is correct to complete the two-way authentication.

5. The vehicle time calibration system based on vehicle central domain control and mobile phone Bluetooth communication according to claim 2, characterized in that: The method for selecting a channel that meets preset requirements for transmitting standardized time data packets using an adaptive frequency hopping algorithm among multiple preset channels for transmitting standardized time data packets includes: when the mobile phone time calibration software and the vehicle-mounted Bluetooth communication unit complete two-way authentication, the vehicle-mounted Bluetooth and the mobile phone time calibration software send test data packets to each other through multiple preset channels for transmitting standardized time data packets. The vehicle-mounted Bluetooth monitors the packet error rate and received signal strength of each channel, and selects the channel with a packet error rate less than a preset threshold and a received signal strength within a set range as the channel that meets the preset requirements. When transmitting standardized time data packets, each channel has a unique sequence number. A random frequency hopping sequence is generated based on the sequence number of the channel that meets the preset requirements, and the standardized time data packets are transmitted sequentially in the channel that meets the preset requirements based on the frequency hopping sequence.

6. A vehicle time calibration system based on vehicle central domain control and mobile phone Bluetooth communication according to claim 2 or 5, characterized in that: The method of reducing the packet loss rate in the transmission of standardized time data packets by adopting a data redundancy transmission mechanism includes: after the mobile time calibration software and the vehicle Bluetooth communication unit complete two-way identity authentication, the mobile time calibration software sends multiple identical standardized time data packets in sequence. Each standardized time data packet is transmitted by hopping according to the frequency hopping sequence generated by the adaptive frequency hopping algorithm in a channel that meets the preset requirements. The vehicle Bluetooth receives the standardized time data packets in sequence and parses and verifies the integrity of the standardized time data packets.

7. The vehicle time calibration system based on vehicle central domain control and mobile phone Bluetooth communication according to claim 6, characterized in that: The method for parsing the standardized time data packets received by the vehicle central domain controller to obtain standard time data and verifying the data integrity of the standard time data includes: the vehicle-mounted Bluetooth communication unit sequentially unpacks the received standardized time data to obtain the original fields of the mobile phone's local time data; the vehicle-mounted Bluetooth communication unit concatenates the mobile phone's local time data and the unique identifier of the mobile phone device into a string in a set order; recalculates the CRC-32 checksum based on the string; compares the original CRC-32 checksum field in the original field of the mobile phone's local time data with the recalculated CRC-32 checksum; when the two checksums are exactly the same, it indicates that the data integrity verification of the corresponding standard time data packet is successful; and the UTC time, local time zone, and daylight saving time status in the original field of the mobile phone's local time data corresponding to the corresponding standard time data packet are used as the standard time data.

8. The vehicle time calibration system based on vehicle central domain control and mobile phone Bluetooth communication according to claim 7, characterized in that: Using the standard time data that has successfully verified data integrity as a benchmark, the time error caused by the drift of the vehicle real-time clock chip is corrected to obtain the corrected standard time. The specific method is as follows: the difference between the timestamp of the most recent time calibration log recorded by the vehicle central domain controller and the timestamp of the standard time data that has successfully verified data integrity is taken as the drift time interval. The product of the drift time interval and the inherent drift coefficient of the vehicle real-time clock chip is taken as the total time drift value. The sum of the total time drift value and the timestamp of the standard time data that has successfully verified data integrity is taken as the calibrated standard time. After each time calibration is completed, the vehicle central domain controller will record a time calibration log. The most recent time calibration log is the time calibration log closest to the current calibration time.

9. A vehicle time calibration method based on vehicle central domain control and mobile phone Bluetooth communication according to claim 1, characterized in that, include: When the vehicle time calibration is triggered, the mobile phone time calibration software is used to obtain the local time data of the mobile phone and encapsulate the local time data of the mobile phone into a standardized time data packet. The mobile time calibration software and the vehicle Bluetooth communication unit automatically perform two-way authentication. After successful two-way authentication, the mobile time calibration software transmits the standardized time data packet to the vehicle central domain controller through the optimized vehicle Bluetooth communication protocol. The standardized time data packets received by the vehicle central domain controller are parsed to obtain standard time data. The standard time data is then verified for data integrity. The standard time data that has successfully passed the data integrity verification is used as a reference to correct the time error caused by the drift of the vehicle real-time clock chip, resulting in the corrected standard time. The vehicle central domain controller then synchronizes the corrected standard time to each domain controller in the vehicle.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method of claim 9.

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