Vehicle emergency starting system and method under keyless entry and starting system fault

Abstract

The invention discloses a vehicle emergency starting system and method under a keyless entry and starting system fault, and belongs to the technical field of automobile electronics. The system comprises a main control module MCU, a low-frequency driving chip and a high-frequency receiving chip. The method comprises the following steps: periodically monitoring an SPI communication state of a low-frequency driving chip through a main control module MCU; when continuous monitoring fails for multiple times, judging a fault and switching to an emergency starting mode; in the mode, the system receives and verifies a legal high-frequency defense unlocking signal actively sent by the intelligent key; after verification succeeds, the vehicle is authorized to be started within a preset time window, and meanwhile continuous warning information is sent to the instrument through the CAN bus; and in the process, the low-frequency driving chip is continuously monitored, and once the communication of the low-frequency driving chip is recovered, the normal key positioning and authentication mode is automatically switched back. The problem that the vehicle cannot be started due to the fault of the low-frequency positioning chip is solved, the emergency starting capability is provided for a driver, and the system reliability and the user experience are improved.

Description

Technical Field

[0001] This invention relates to the field of automotive electronics technology, and more specifically, to a system and method for ensuring emergency vehicle start-up when the low-frequency drive chip of a keyless entry and start system malfunctions. Background Technology

[0002] With the increasing demand for intelligent and comfortable vehicles, keyless entry and push-button start systems have become standard features in modern vehicles. This system uses low-frequency signals to locate a valid key inside or around the vehicle and receives remote control commands via high-frequency signals, enabling convenient unlocking and starting.

[0003] However, the reliability of this system highly depends on the proper functioning of each chip module. In practical applications, the driver chip responsible for transmitting low-frequency positioning signals may fail due to electrostatic interference, electrical faults, or communication anomalies. Once the low-frequency chip malfunctions, the PEPS control unit will be unable to locate and authenticate the key through the normal process, directly causing the vehicle to fail to start, resulting in the so-called "safety-breakage" problem, which seriously affects the user experience and even poses safety hazards in emergencies. Existing technologies typically focus on the normal coordination of various functional modules and lack robust designs for single-point failures of such critical chips. When the low-frequency chip malfunctions, the vehicle often completely loses its starting capability, and users can only wait for roadside assistance or tow truck repairs, leading to high complaint rates and significant processing costs.

[0004] Patent No. (CN201410834214) discloses a wireless communication testing system and method for a car keyless entry and keyless start system. The system includes a controller testing system and a key testing system. The wireless communication test is decomposed into inspection tests of two types of transmitters and two types of receivers. In terms of function, it ensures the production qualification of components; in terms of performance, it ensures the rationality and accuracy of various communication parameters, thereby ensuring the wireless communication stability of the PEPS system.

[0005] However, the above inventions mainly focus on the wireless communication function testing of PEPS systems during the production stage. Although they can ensure the communication qualification of components when they leave the factory, they are essentially a passive testing method. They lack an emergency handling mechanism for the failure of some communication modules, such as low-frequency drive chips, in actual use, and cannot solve the "safety and safety" problem of vehicles being unable to start due to abnormal key finding function. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a vehicle starting system and implementation method for a keyless entry and start system in case of a malfunction in the key-finding chip. When the low-frequency drive chip responsible for key positioning malfunctions, this system can automatically activate an emergency start mode, allowing the vehicle to start within a limited time while providing a clear warning to the user. This effectively avoids vehicle paralysis caused by a single point of failure, improving system availability and user satisfaction.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a vehicle emergency start system for keyless entry and start system malfunctions, comprising: a main control module MCU, a low-frequency drive chip 1, and a high-frequency receiver chip 2; the main control module MCU is connected to the low-frequency drive chip 1 via an SPI interface to monitor the working status of the low-frequency drive chip in real time; the low-frequency drive chip 1 is coupled to the low-frequency antenna of the main control module MCU and generates a low-frequency positioning signal according to the instructions of the main control module MCU under normal conditions; the high-frequency receiver chip 2 is coupled to the high-frequency antenna of the main control module MCU to receive high-frequency radio frequency signals from the vehicle key; wherein, when the main control module MCU detects a communication abnormality in the low-frequency drive chip 1, the system switches to emergency start mode: the main control module MCU authorizes vehicle start within a preset time based on the legitimate high-frequency de-protection signal received by the high-frequency receiver chip 2, and maintains an alert indicating the low-frequency drive chip 2 is malfunctioning during vehicle start-up.

[0008] Furthermore, the main control module MCU periodically sends status query commands to the low-frequency driver chip 1 through the SPI interface, and determines whether the low-frequency driver chip 1 is working properly based on whether a correct response signal is received within a predetermined time.

[0009] Furthermore, after the main control module MCU fails to receive a correct response from the low-frequency drive chip 1 multiple times, it determines that the low-frequency drive chip 1 has malfunctioned and triggers the emergency start mode.

[0010] Furthermore, the legitimate high-frequency decryption signal received by the high-frequency receiving chip 2 is a remote unlocking signal that has been successfully verified by the vehicle safety authentication algorithm.

[0011] Furthermore, the preset time is a fixed duration starting from the receipt of a legitimate high-frequency de-escalation signal. Within this duration, the main control module (MCU) allows the engine to start; if the engine fails to start within this duration, the main control module (MCU) exits the emergency start mode.

[0012] Furthermore, the main control module MCU sends a warning message to the vehicle's instrument control unit via the vehicle's CAN bus, alerting the user to a key positioning system malfunction.

[0013] Furthermore, the main control module MCU continuously monitors the communication status of the low-frequency driver chip 1 in emergency start mode; if the low-frequency driver chip is detected to have resumed normal communication within or after the time window, the main control module MCU automatically exits the emergency start mode and resumes the normal key positioning and authentication process based on the low-frequency signal.

[0014] Furthermore, the low-frequency drive chip 1 operates at a frequency of 125kHz and locates and identifies the vehicle key within or around the vehicle; the high-frequency receiver chip 2 operates in the UHF band and receives the high-frequency remote control signal sent by the vehicle key.

[0015] The present invention also provides a control method for a vehicle emergency starting system in the event of a keyless entry and start system failure, comprising the following steps: S1: The communication status of the low-frequency drive chip 1 is periodically monitored by the main control module MCU; S2: When the main control module MCU fails to receive a correct response from the low-frequency drive chip 1 multiple times in a row, it determines that the communication of the low-frequency drive chip 1 is abnormal and switches to the emergency start mode. S3: The main control module MCU receives and verifies the key de-protection signal from the high-frequency receiver chip 2; S4: If the key unlock signal is valid, the vehicle is allowed to start within a preset time, and an alarm message indicating that the key has not been found is sent to the instrument panel via the CAN bus. S5: If the low-frequency drive chip 1 is detected to return to normal within the preset time, switch back to normal key positioning and authentication mode.

[0016] Furthermore, "multiple consecutive times" is 5 times, and "preset time" is 3 minutes.

[0017] The vehicle emergency starting system and method for keyless entry and start system failure of the present invention has the following advantages: (1) Through system-level redundancy design, this invention utilizes the existing high-frequency communication channel as an emergency authentication method when the low-frequency drive chip fails, ensuring the vehicle's startability in most cases and solving the safety and safety issues caused by it.

[0018] (2) The emergency start mode proposed in this invention is not a permanent authorization, but is limited to a short preset time after being triggered by a legitimate high-frequency signal. This satisfies the need for temporary vehicle relocation or driving to a repair shop, while preventing the long-term activation of security permissions.

[0019] (3) While providing emergency start function, the system of the present invention will inform the user of the system abnormality through the main control module MCU and other modules such as the instrument control unit, guide the user to repair in time, and improve the user experience.

[0020] (4) The system of the present invention can continuously monitor the status of the low-frequency drive chip. Once the abnormality is eliminated, it can automatically switch back to the normal mode with better performance and complete security without user intervention, which reflects the intelligence and reliability of the system. Attached Figure Description

[0021] This manual includes the following figures, which illustrate the following: Figure 1 This is an overall logical structure diagram of a vehicle emergency starting system under the fault of the keyless entry and start system of the present invention; Figure 2 This is a circuit schematic diagram of the low-frequency drive chip of the present invention; Figure 3 This is a circuit schematic diagram of the high-frequency receiving chip of the present invention; Figure 4 This is an overall flowchart of the control method of the system described in this invention; Among them, 1. Low-frequency driver chip; 2. High-frequency receiver chip. Detailed Implementation

[0022] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, in order to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention, and to facilitate its implementation.

[0023] like Figure 1 The diagram shown illustrates the overall logical structure of the system of this invention. The vehicle emergency start system under conditions of keyless entry and start system failure comprises the following core hardware components: a main control module (MCU), a low-frequency drive chip 1, and a high-frequency receiver chip 2. The main control module (MCU) is connected to the low-frequency drive chip 1 via an SPI interface to monitor its operating status in real time. The low-frequency drive chip 1 is coupled to the low-frequency antenna of the main control module (MCU) and generates a low-frequency positioning signal according to the instructions of the main control module (MCU) under normal conditions. The high-frequency receiver chip 2 is coupled to the high-frequency antenna of the main control module (MCU) to receive high-frequency radio frequency signals from the vehicle key.

[0024] The main control MCU application supports SPI communication interface, has CAN controller, and features strong processing power and low power consumption characteristics, making it an automotive-grade microcontroller. Examples include NXP's S32K series, Infineon's AURIX™ series, or ST's SPC5 series. These MCUs all have rich communication peripherals, high reliability, and comply with the AEC-Q100 standard, making them suitable for PEPS system control.

[0025] like Figure 2The diagram shows the circuit schematic of low-frequency driver chip 1. Dedicated low-frequency driver chips such as NJJ29C0, NJJ29C2, or ATA5296 can be used. This chip is directly connected to the main control module MCU via a serial peripheral interface (SPI). The SPI interface is responsible for transmitting commands from the main control module MCU, such as signal transmission commands, status query commands, and receiving response signals from the low-frequency driver chip. The output of low-frequency driver chip 1 is connected to multiple low-frequency antennas arranged inside and around the vehicle. Under the control of the main control module MCU, low-frequency driver chip 1 modulates digital commands to generate a 125kHz low-frequency carrier signal, which is then radiated through the low-frequency antennas to form a positioning field used to wake up and locate users carrying legitimate keys.

[0026] like Figure 3 The diagram shows the circuit schematic of the high-frequency receiver chip 2. High-sensitivity, low-power UHF receiver chips such as the ATA5785 or ATA5781 can be used. This chip connects to the main control module MCU via a corresponding data interface, and its input is connected to the vehicle's high-frequency antenna. It typically operates in the UHF band, such as 315MHz, 433MHz, or 868MHz. The high-frequency receiver chip 2 receives high-frequency radio frequency signals from the smart key, such as remote unlocking, locking, and car finding command signals, or authentication signals sent when the key passively responds. It demodulates and decodes the signals, and transmits the resulting digital data packets to the main control module MCU for security authentication processing.

[0027] Under normal, fault-free system conditions, the keyless entry and start process for the vehicle is as follows: When the user approaches the vehicle with a valid key or presses the request switch on the door handle, the main control module (MCU) sends a command to the low-frequency driver chip 1 via the SPI interface. The low-frequency driver chip 1 drives the corresponding low-frequency antenna to transmit a 125kHz low-frequency positioning signal. After the low-frequency receiving circuit inside the key is activated, it sends a high-frequency key decryption signal containing encrypted identity information to the vehicle through its high-frequency transmitting circuit. The vehicle's high-frequency receiving chip 2 receives and demodulates this signal before sending it to the main control module (MCU). The main control module (MCU) then uses its internal security authentication algorithm to verify the signal.

[0028] If the verification is successful, the main control module (MCU) determines that a valid key has been found. It then sends an authorization command to the relevant control unit via the CAN bus, allowing the user to unlock the car door. When the user enters the vehicle and presses the start button, the main control module (MCU), after confirming the key is inside the vehicle using the in-vehicle low-frequency antenna, authorizes the engine control unit to start the engine, completing the one-button start process.

[0029] like Figure 4 The diagram shown is the overall flowchart of the keyless entry and start process for a vehicle in a faulty state: S1: A periodic timer task is set in the software program of the main control module MCU. In this task, the main control module MCU sends a specific status query command to the low-frequency driver chip 1 via the SPI interface. After sending the command, the main control module MCU starts an internal timer to wait for the response data from the low-frequency driver chip 1. Normal response data should include the preset correct status code or register value. The main control module MCU determines whether a single query is normal based on two conditions: a) whether a response is received within a predetermined time, such as 10 milliseconds; b) whether the content of the received response data is a correct response signal. If a timeout or incorrect response occurs, a communication failure is recorded.

[0030] S2: To avoid misjudgments caused by momentary interference, the main control module (MCU) sets a fault confirmation threshold. When the MCU detects that it has failed to receive a correct response from the low-frequency drive chip 1 five consecutive times, it determines that the low-frequency drive chip 1 has a communication abnormality or functional failure. At this time, the MCU sets the "low-frequency chip fault" flag in its internal status and immediately triggers the emergency start mode. Simultaneously, the MCU sends a clear diagnostic and warning message, such as "Key positioning system fault, please have it checked promptly," to the instrument control unit via the CAN bus. The corresponding fault indicator light on the instrument panel illuminates, possibly accompanied by text prompts, informing the user that the system is abnormal but the vehicle still has emergency start capability.

[0031] S3: In emergency start mode, the system no longer attempts to wake up or locate the key via low-frequency signals. At this time, the user needs to actively operate a physical button on the smart key, such as the unlock button, to send a high-frequency key unlock signal. The high-frequency receiver chip 2 receives this signal and transmits it to the main control module (MCU). The MCU also calls a security authentication algorithm to verify the high-frequency unlock signal. The verification process includes: checking if the data packet format is correct; verifying the validity of the encrypted information to ensure the signal comes from a legitimate vehicle key; and confirming that the unlock command is currently valid. Only after passing all security checks is the signal deemed a "legitimate high-frequency unlock signal." If the verification fails, the MCU does not execute any startup authorization, and the system remains in a state of waiting for a legitimate command.

[0032] S4: If the main control module MCU verifies that the received high-frequency de-protection signal is a "legitimate signal". The main control module (MCU) immediately opens a fixed 3-minute time window. This timer starts from the moment the verification is successful. Within this 3-minute window, the MCU authorizes the vehicle to perform the starting procedure: the user presses the one-button start button inside the vehicle. After confirming that the vehicle is in emergency start mode and the time window is valid, the MCU bypasses the check of the key's low-frequency positioning information. The MCU directly sends a "start allowed" command to the engine control unit via the CAN bus. The engine can start normally, and the vehicle can be driven in gear. Throughout the emergency start mode, the MCU periodically sends fault warning information to the instrument control unit via the CAN bus, maintaining the warning lights and prompts on the instrument panel to ensure that the user is continuously aware that the system is in a degraded operating state. If the user does not start the vehicle within 3 minutes of authorization, or if the vehicle is started and then turned off again and the time window expires, the MCU will automatically exit the emergency start mode after the timer expires. At this time, even if the start button is pressed, the MCU will not authorize the start. The user must press the key unlock button again to obtain a new 3-minute authorization window, triggering a new round of S3 verification and S4 authorization procedures.

[0033] S5: During emergency start mode activation, the main control module MCU periodically queries the status of low-frequency drive chip 1 via the SPI interface. If, within the 3-minute emergency start time window, or at any time thereafter, the MCU confirms through 2-3 consecutive successful status queries that communication with low-frequency drive chip 1 has returned to normal, the main control module MCU immediately and automatically clears the "low-frequency chip fault" flag and exits the emergency start mode. Subsequent key positioning will again rely on the 125kHz signal emitted by low-frequency drive chip 1. The main control module MCU notifies the instrument control unit to clear the relevant fault indication via the CAN bus, and the instrument panel warning lights turn off. After this, the vehicle entry and start process is fully restored to the standard keyless operation mode.

[0034] When the low-frequency drive chip responsible for key positioning fails due to static electricity, electrical faults, or communication anomalies, the traditional PEPS system will be completely unable to start the vehicle, resulting in a "safe breakdown." This invention introduces an emergency start mode based on a high-frequency backup channel, creating system-level redundancy. The vehicle transforms from "completely paralyzed" to "emergency-ready." In the event of such a failure, users do not need to wait for towing; they can simply use the key to remotely unlock the vehicle and obtain temporary starting permission to move it to a safe location or drive it to a repair shop. This fundamentally avoids the loss of core mobility functions due to a single point of failure in comfort features, significantly reducing user complaints and safety risks in emergency situations.

[0035] The system uses the main control module (MCU) to periodically interact with the low-frequency driver chip via SPI commands and verify its status. Employing a "multiple consecutive failures" logic, it achieves accurate and reliable chip fault detection. Upon fault detection, the system logic automatically switches to a preset emergency startup mode. This ensures timely fault detection and avoids misjudgments. The entire process from fault occurrence to the activation of the backup plan is completed automatically by the system; no additional settings or operations are required from the user, demonstrating a high degree of intelligence and a seamless user experience.

[0036] This invention provides emergency functionality while strictly ensuring vehicle safety. The emergency start mode is triggered strictly by a "legitimate high-frequency decryption signal" verified by the original vehicle's security authentication algorithm. The anti-counterfeiting and encryption strength of this signal is consistent with the normal mode. Furthermore, start authorization is restricted to a fixed, short time window. This design ensures the "temporariness" and "controllability" of emergency start. It satisfies the need for temporary vehicle relocation while preventing vehicle permissions from being granted indefinitely or for extended periods, effectively plugging potential security vulnerabilities and maintaining the integrity of the entire vehicle's safety system.

[0037] Once the system enters emergency start mode, the main control module (MCU) immediately and continuously sends fault warning information to the instrument panel via the CAN bus. The clear indication on the instrument panel allows the driver to clearly understand that the system is currently in a degraded operating state, preventing potential problems from being overlooked due to lack of awareness. This guides users to promptly perform professional maintenance when convenient, preventing minor faults from escalating into major issues and improving vehicle maintenance management.

[0038] Even in emergency mode, the system does not abandon monitoring the source of the fault. The main control module (MCU) continuously attempts to communicate with the low-frequency driver chip, and once it detects that the chip has returned to normal, it automatically and seamlessly switches back to normal mode. If the fault is caused by a transient strong interference, the system will automatically resume normal operation once the interference disappears, and the user may not even be aware that an anomaly occurred. This greatly enhances the system's adaptability to interference in complex environments and its long-term operational reliability.

[0039] This invention requires no additional dedicated hardware. Its core is an improved control algorithm and logic running on the main control module (MCU), fully utilizing the existing high-frequency receiving channel, CAN communication network, and instrument display resources of the PEPS system. Without significantly increasing hardware costs, it can provide existing systems with robust fault-handling capabilities through software upgrades, offering extremely high cost-effectiveness and ease of application on existing vehicle platforms or deployment in new models.

[0040] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A vehicle emergency starting system for a malfunctioning keyless entry and start system, characterized in that, include: The system comprises a main control module (MCU), a low-frequency drive chip (1), and a high-frequency receiver chip (2). The main control module (MCU) is connected to the low-frequency drive chip (1) via an SPI interface and monitors the working status of the low-frequency drive chip in real time. The low-frequency drive chip (1) is coupled to the low-frequency antenna of the main control module (MCU) and generates a low-frequency positioning signal according to the instructions of the main control module (MCU) under normal conditions. The high-frequency receiver chip (2) is coupled to the high-frequency antenna of the main control module (MCU) and receives a high-frequency radio frequency signal from the vehicle key. When the main control module (MCU) detects a communication abnormality in the low-frequency drive chip (1), the system switches to an emergency start mode: the main control module (MCU) authorizes the vehicle to start within a preset time based on the legitimate high-frequency de-protection signal received by the high-frequency receiver chip (2) and maintains an abnormality warning for the low-frequency drive chip (2) during vehicle start-up.

2. The vehicle emergency starting system for a keyless entry and start system malfunction as described in claim 1, characterized in that, The main control module (MCU) periodically sends status query commands to the low-frequency drive chip (1) through the SPI interface, and determines whether the low-frequency drive chip (1) is working properly based on whether a correct response signal is received within a predetermined time.

3. The vehicle emergency starting system for a keyless entry and start system malfunction as described in claim 2, characterized in that, After the main control module (MCU) fails to receive a correct response from the low-frequency drive chip (1) multiple times, it determines that the low-frequency drive chip (1) has malfunctioned and triggers the emergency start mode.

4. The vehicle emergency starting system for a keyless entry and start system malfunction as described in claim 1, characterized in that, The legitimate high-frequency unlocking signal received by the high-frequency receiving chip (2) is a remote unlocking signal that has been successfully verified by the vehicle safety authentication algorithm.

5. A vehicle emergency starting system for a keyless entry and start system malfunction as described in claim 1, characterized in that, The preset time is a fixed duration starting from the receipt of the legitimate high-frequency de-escalation signal. Within this duration, the main control module (MCU) allows the engine to start. If the engine fails to start within this duration, the main control module (MCU) exits the emergency start mode.

6. A vehicle emergency starting system for a keyless entry and start system malfunction as described in claim 1, characterized in that, In the emergency start mode, the main control module (MCU) sends a warning message to the vehicle's instrument control unit via the vehicle's CAN bus, alerting the user that there is an abnormality in the key positioning system.

7. The vehicle emergency starting system for a keyless entry and start system malfunction as described in claim 1, characterized in that, The main control module (MCU) continuously monitors the communication status of the low-frequency driver chip (1) in the emergency start mode; if the low-frequency driver chip is detected to resume normal communication within or after the time window, the main control module (MCU) automatically exits the emergency start mode and resumes the normal key positioning and authentication process based on the low-frequency signal.

8. A vehicle emergency starting system for a keyless entry and start system malfunction as described in claim 1, characterized in that, The low-frequency drive chip (1) operates at a frequency of 125kHz and locates and identifies the vehicle key within or around the vehicle; the high-frequency receiver chip (2) operates in the UHF band and receives the high-frequency remote control signal sent by the vehicle key.

9. A control method for a vehicle emergency starting system under a malfunction of a keyless entry and start system, based on any one of claims 1-8, characterized in that, Includes the following steps: S1: The communication status of the low-frequency drive chip (1) is periodically monitored by the main control module (MCU); S2: When the main control module (MCU) fails to receive a correct response from the low-frequency drive chip (1) multiple times in a row, it is determined that the communication of the low-frequency drive chip (1) is abnormal, and the system switches to emergency start mode. S3: The main control module (MCU) receives and verifies the key unlocking signal from the high-frequency receiving chip 2; S4: If the key unlock signal is valid, the vehicle is allowed to start within a preset time, and an alarm message indicating that the key has not been found is sent to the instrument panel via the CAN bus. S5: If the low-frequency drive chip (1) is detected to return to normal within the preset time, switch back to normal key positioning and authentication mode.

10. The control method for emergency vehicle starting under a keyless entry and start system malfunction according to claim 9, characterized in that, The term "continuously multiple times" refers to 5 times, and the term "preset time" refers to 3 minutes.

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