Method, device and equipment for automatic recovery of engine valve timing retardation fault

Abstract

The application discloses an engine valve timing delay fault automatic recovery method, device and equipment, and the method comprises the following steps: when it is detected that the variable valve timing system has a camshaft timing delay fault, and the locking mechanism of the variable valve timing system enters a locking state, the operating state parameters of the variable valve timing system are acquired; according to the matching result of the operating state parameters and the preset fault condition, the fault type is determined; if the fault type is a temporary fault, the triggering of the engine degradation protection mode is shielded; when the fault recovery condition is met, the variable valve timing system is controlled to perform a phase reset operation, the locking state of the locking mechanism is released after the reset is completed, and the variable valve timing system is controlled to follow the target timing phase operation, so that the engine power limitation caused by the temporary fault is effectively avoided, the fault is automatically recovered, and manual maintenance is not needed.

Description

Technical Field

[0001] This application relates to the field of engine control, specifically to an automatic recovery method, device, and equipment for engine valve timing retardation faults. Background Technology

[0002] Variable Valve Timing (VVT) is a key actuator in automotive engines used to optimize valve opening and closing times, improve power performance, and enhance fuel economy. During engine operation, the VVT ​​system achieves precise control of valve timing by adjusting the relative phase between the camshaft and crankshaft. However, in real-world applications, the VVT ​​system is highly susceptible to factors such as voltage fluctuations, unstable wiring harness connections, or aging mechanical components, which can lead to timing control deviations, the most typical of which is camshaft timing retardation.

[0003] When the existing engine control logic detects a camshaft timing retardation fault, the control system forcibly triggers a limp-home mode. Once in this mode, the engine management system directly limits the engine's torque, speed, and power output, resulting in a significant drop in vehicle power. While this protection mechanism provides some hardware safety, it severely impacts the vehicle's normal driving ability and experience in the face of recoverable temporary faults, causing unnecessary power loss.

[0004] When the VVT ​​system automatically returns to its initial default position due to an abnormal power outage, its internal locking mechanism remains locked to prevent uncontrolled valve movement. However, in the existing control logic, even after power is restored and the original electrical fault has been resolved, the VVT ​​actuator remains mechanically stuck and unable to follow the target timing. Because the fault cannot be eliminated automatically, the vehicle will remain in a restricted state for an extended period, requiring manual inspection and forced reset to restore normal operation. This not only increases the user's maintenance and time costs but also reduces the vehicle's intelligence and reliability. Summary of the Invention

[0005] This application provides an automatic recovery method, device, and equipment for engine valve timing retardation faults, which can solve the technical problem in the prior art that valve timing retardation faults can only be recovered by manual intervention after they occur, and cannot achieve automatic recovery of temporary faults while ensuring system safety.

[0006] In a first aspect, embodiments of this application provide an automatic recovery method for an engine valve timing retardation fault, the automatic recovery method for an engine valve timing retardation fault comprising: When a camshaft timing retardation fault is detected in the variable valve timing system and its locking mechanism is locked, the operating status parameters of the variable valve timing system are acquired. The fault type is determined based on the matching result between the operating status parameters and the preset fault conditions; If the fault type is a temporary fault, then the triggering of the engine degradation protection mode will be disabled; When the fault recovery conditions are met, the variable valve timing system is controlled to perform a phase reset operation, and after the reset is completed, the locking state of its locking mechanism is released, and the variable valve timing system is controlled to follow the target timing phase.

[0007] In conjunction with the first aspect, in one implementation, detecting the presence of a camshaft timing retardation fault includes: If the timing retardation angle of the detected camshaft is greater than a preset first angle threshold, or the response delay of the variable valve timing system is greater than a preset delay duration threshold, then the camshaft timing retardation fault is determined to exist.

[0008] In conjunction with the first aspect, in one embodiment, the operating state parameters of the variable valve timing system include at least one of the following: The position feedback signal of the variable valve timing sensor, the power supply voltage of the variable valve timing actuator, and the connection status of the circuit; The variable valve timing sensor includes a camshaft position sensor, and the position feedback signal includes the camshaft timing phase signal.

[0009] In conjunction with the first aspect, in one implementation, determining the fault type based on the matching result of the operating status parameters and preset fault conditions includes: If the power supply voltage drops to less than or equal to a preset first voltage threshold and the drop duration is less than or equal to a preset drop duration threshold, and the single interruption duration of the position feedback signal of the variable valve timing sensor is less than or equal to a preset interruption duration threshold, and the power supply voltage and the position feedback signal recover to normal on their own within a preset monitoring time, then the fault type is determined to be a temporary fault. Alternatively, if the power supply voltage is less than or equal to the first voltage threshold and the duration is greater than the drop duration threshold, or the position feedback signal is continuously interrupted for a duration greater than the interruption duration threshold, or the timing retardation angle of the camshaft is greater than a preset second angle threshold, then the fault type is determined to be a permanent hardware fault.

[0010] In conjunction with the first aspect, in one implementation, when the fault recovery conditions are met, controlling the variable valve timing system to perform a phase reset operation includes: Once the power supply voltage and the position feedback signal return to normal, the variable valve timing system is controlled to adjust the camshaft phase with a preset initial reference phase as the target. When the deviation between the actual phase of the camshaft and the initial reference phase is less than a preset first phase deviation threshold, and the holding time is greater than or equal to a preset holding time threshold, the phase reset of the variable valve timing system is determined to be complete.

[0011] In conjunction with the first aspect, in one embodiment, releasing the locking state of the variable valve timing system lock-up mechanism includes: Output an unlocking pulse signal to the lock-up solenoid valve of the variable valve timing system to perform a single forced unlocking operation on the lock-up mechanism; Update the locking mechanism status flag to unlocked and prevent repeated transmission of the unlock pulse signal.

[0012] In conjunction with the first aspect, in one embodiment, controlling the variable valve timing system to operate in accordance with the target timing phase includes: The corresponding timing parameter MAP is found based on the engine speed, load and water temperature to obtain the corresponding target timing phase; The variable valve timing system is controlled to drive the camshaft in a phase that approximates the target timing phase. The deviation between the actual timing phase of the camshaft and the target timing phase is monitored in real time. If the deviation is greater than a preset phase correction threshold and the duration is greater than a preset duration threshold, the control parameters of the variable valve timing system are automatically corrected until the actual timing phase reaches the target timing phase.

[0013] In conjunction with the first aspect, in one embodiment, after controlling the variable valve timing system to operate in accordance with the target timing phase, the method further includes: Within multiple consecutive cycles, it is verified whether the power supply voltage is within the normal voltage range, whether the position feedback signal is not interrupted, and whether the timing phase deviation is less than a preset second deviation threshold. If so, clear the fault code for the camshaft timing retardation fault and disable the engine degradation protection mode. Otherwise, if the camshaft timing retardation fault occurs again during the verification period, the variable valve timing system reset and locking mechanism unlocking operation will be re-executed.

[0014] In conjunction with the first aspect, in one implementation, the method further includes: Count the number of times the variable valve timing system performs a reset operation; If the cumulative number of attempts exceeds a preset threshold, the reset operation will be stopped, and the fault type will be updated to a permanent hardware fault.

[0015] In conjunction with the first aspect, in one implementation, the method further includes: If the fault type is a permanent hardware fault, the engine degrade protection mode is activated, the fault code of the camshaft timing retardation fault is stored, and a fault alarm is issued.

[0016] Secondly, embodiments of this application provide an automatic recovery device for engine valve timing retardation faults, the automatic recovery device for engine valve timing retardation faults comprising: The acquisition module is used to acquire the operating status parameters of the variable valve timing system when a camshaft timing retardation fault is detected in the variable valve timing system and its locking mechanism is locked. The determination module is used to determine the fault type based on the matching result between the operating status parameters and preset fault conditions; A shielding module is used to shield the triggering of the engine degradation protection mode if the fault type is a temporary fault. The control module is used to control the variable valve timing system to perform a phase reset operation when the fault recovery conditions are met, and to release the locking state of its locking mechanism after the reset is completed, and to control the variable valve timing system to follow the target timing phase.

[0017] Thirdly, embodiments of this application provide an automatic recovery device for engine valve timing retardation faults. The automatic recovery device for engine valve timing retardation faults includes a processor, a memory, and an automatic recovery program for engine valve timing retardation faults stored in the memory and executable by the processor. When the automatic recovery program for engine valve timing retardation faults is executed by the processor, it implements the steps of the automatic recovery method for engine valve timing retardation faults as described in any of the preceding claims.

[0018] The beneficial effects of the technical solutions provided in this application include: pass When a camshaft timing retardation fault is detected in the variable valve timing system and its locking mechanism is locked, the operating status parameters of the variable valve timing system are acquired. Based on the matching result of the operating status parameters and preset fault conditions, the fault type is determined. If the fault type is a temporary fault, the triggering of the engine degradation protection mode is disabled. When the fault recovery conditions are met, the variable valve timing system is controlled to perform a phase reset operation. After the reset is completed, the locking state of its locking mechanism is released, and the variable valve timing system is controlled to follow the target timing phase. This effectively avoids the engine power limitation caused by the engine valve timing retardation fault mistakenly triggering the engine degradation protection, thus improving the automation level of fault recovery and vehicle operating efficiency. By adding a reset and unlock logic for the variable valve timing system, the problem of locking after return to the original position is solved at its root. Combined with a fast camshaft phase following strategy, the variable valve timing system can restore its normal adjustment capability. At the same time, the control logic of resetting before unlocking ensures mechanical safety during the reset process, allowing the fault to recover automatically without manual inspection, significantly reducing maintenance costs and improving the user experience. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating an embodiment of the automatic recovery method for engine valve timing retardation fault according to this application. Figure 2 This is a functional module diagram of an embodiment of the automatic recovery device for engine valve timing retardation fault according to this application; Figure 3 This is a schematic diagram of the hardware structure of the automatic recovery device for engine valve timing retardation fault involved in the embodiments of this application. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0021] First, some of the technical terms used in this application will be explained to help those skilled in the art understand this application.

[0022] VVT: Variable Valve Timing. In this application, the variable valve timing system (hereinafter referred to as the VVT ​​system) refers to a system that can dynamically adjust the opening and closing times of the valves according to the engine operating conditions. Its basic principle is to optimize the intake efficiency of the engine by changing the phase angle of the camshaft relative to the crankshaft, thereby improving power, fuel economy and reducing emissions. The VVT ​​system in this application includes at least a variable valve timing actuator (also known as a phaser), a position sensor (such as a camshaft position sensor), a lock-up solenoid valve and an internal mechanical lock-up mechanism.

[0023] EMS: Engine Management System.

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0025] In a first aspect, embodiments of this application provide an automatic recovery method for engine valve timing retardation faults.

[0026] In one embodiment, reference is made to Figure 1 , Figure 1 This is a schematic flowchart illustrating the first embodiment of the automatic recovery method for engine valve timing retardation fault according to this application. Figure 1 As shown, the automatic recovery method for engine valve timing retardation faults includes: Step S101: When a camshaft timing retardation fault is detected in the variable valve timing system and its locking mechanism enters the locking state, the operating status parameters of the variable valve timing system are obtained.

[0027] In this embodiment, the operating status of the variable valve timing (VVT) system is monitored in real time using an EMS controller at a high-frequency sampling rate of ≥10 times / second. When a camshaft timing retardation fault is detected, the operating status parameters of the variable valve timing system are immediately acquired for subsequent fault type determination.

[0028] Specifically, detecting a camshaft timing retardation fault includes the following steps: The EMS controller uses the timing phase acquired by the camshaft position sensor to calculate the difference between the actual timing phase and the target timing phase of the camshaft in real time, thus obtaining the camshaft timing retardation angle. Simultaneously, the EMS controller monitors the time interval from issuing the timing adjustment command to the camshaft actually starting to move, i.e., the response delay duration.

[0029] If the camshaft timing retardation angle is greater than the preset first angle threshold, or the response delay of the variable valve timing system is greater than the preset delay duration threshold, the EMS controller determines that there is a camshaft timing retardation fault and triggers the corresponding P0012 fault code.

[0030] In this embodiment, the first angle threshold is set to 5°, and the delay time threshold is set to 200ms. That is, when the VVT ​​timing retardation angle is detected to be >5°, or the response lag time is >200ms, the P0012 fault code is triggered. The above angle threshold and duration are only one optional embodiment, and can be calibrated according to the engine operating conditions in actual applications.

[0031] In one embodiment, the operating status parameters of the variable valve timing system include at least one of the following: the position feedback signal of the variable valve timing sensor, the power supply voltage of the variable valve timing actuator, and the connection status of the circuit; wherein, the variable valve timing sensor includes a camshaft position sensor, and the position feedback signal includes the timing phase signal of the camshaft.

[0032] It is important to understand that when the EMS controller determines that there is a camshaft timing retardation fault (triggers fault code P0012), before starting the fault type determination logic, the EMS controller will first perform preliminary safety procedures: control the variable valve timing system to stop the current timing adjustment action and automatically return the camshaft to the preset initial reference phase to avoid the camshaft being in an extreme phase under fault conditions, which would cause engine instability; at the same time, control the internal locking mechanism of the variable valve timing system to enter and maintain a safe lock-up state. The purpose of maintaining the lock-up state here is to prevent the camshaft from experiencing mechanical shock due to excessive phase deviation before the fault type is determined.

[0033] Step S102: Determine the fault type based on the matching result between the operating status parameters and the preset fault conditions.

[0034] The fault types in this embodiment include temporary faults and permanent hardware faults. By setting a quantitative judgment threshold, it is possible to accurately distinguish between temporary faults and permanent hardware faults, thus preventing misjudgments.

[0035] In one embodiment, temporary faults can be identified using three quantitative indicators: First, the power supply voltage indicator: the variable valve timing actuator power supply voltage momentarily drops from the rated operating voltage of 12V to less than or equal to a preset first voltage threshold of 6V, and the drop duration is less than or equal to a preset drop duration threshold of 100ms, constituting a momentary power outage rather than a sustained undervoltage. Second, the signal interruption indicator: the position feedback signal of the variable valve timing sensor momentarily interrupts, and the duration of a single interruption is less than or equal to a preset interruption duration threshold of 3s, with no continuous frame drops during the interruption. Third, the automatic recovery indicator: after the voltage drop and signal interruption, without external intervention, the power supply voltage recovers to the normal operating voltage within a preset monitoring time of 1s, and the position feedback signal automatically returns to normal. If the operating status parameters simultaneously meet the above three quantitative indicators, the EMS controller determines the fault type as a temporary, non-hardware damage fault.

[0036] It is worth noting that temporary faults are usually caused by external interference, power fluctuations, or poor contact. For example, a vehicle passing over a bumpy road may cause a momentary poor contact in the wiring harness, or there may be a voltage fluctuation at the moment of startup. If the voltage and signal can recover on their own within a short time, it indicates that the hardware itself is not damaged and has the conditions for automatic recovery.

[0037] In one embodiment, if the operating status parameters meet any of the following indicators, the EMS controller determines the fault type as a permanent hardware fault: First, the power supply voltage of the variable valve timing actuator is continuously less than or equal to the first voltage threshold of 6V and the duration is greater than the drop duration threshold of 100ms; Second, the position feedback signal of the variable valve timing sensor is continuously interrupted for a duration greater than the interruption duration threshold of 3s; Third, the timing retardation angle of the camshaft is greater than the preset second angle threshold of 10° and there is no tendency for it to retrace.

[0038] It is worth noting that permanent hardware failures are usually caused by component damage, such as a control valve coil open circuit causing continuous voltage abnormality, sensor damage causing continuous signal loss, or mechanical sticking of the variable valve timing phaser causing excessive timing deviation that cannot be adjusted. Such failures cannot be recovered by software reset and require hardware repair.

[0039] In an optional embodiment, when the EMS controller determines the fault type to be a permanent hardware fault according to the above steps, it triggers the engine limp-home mode, causing the engine to enter a degraded protection state, limiting the engine's torque, speed, and power output to prevent the fault from escalating and ensuring engine hardware safety. Simultaneously, the EMS controller stores the P0012 fault code for the camshaft timing retardation fault and issues a fault alarm through the fault indicator light on the instrument panel to remind the driver to perform timely maintenance. Through these measures, this application can prioritize ensuring the safe operation of the engine and vehicle in severe fault scenarios where automatic recovery is not possible, avoiding irreversible mechanical damage.

[0040] Step S103: If the fault type is a temporary fault, then disable the triggering of the engine degradation protection mode.

[0041] It is worth noting that the engine degradation protection mode can be the engine limp-home mode. When the fault type is temporary, the EMS controller blocks and locks the triggering of the engine limp-home mode, without limiting the engine's torque, speed, and power output, maintaining the vehicle's full-function normal driving state, thereby avoiding power limitation caused by the temporary fault mistakenly triggering the limp-home mode.

[0042] Step S104: When the fault recovery conditions are met, control the variable valve timing system to perform a phase reset operation, and after the reset is completed, release the locking state of its locking mechanism, and control the variable valve timing system to follow the target timing phase.

[0043] In one embodiment, step S104 specifically includes: after the power supply voltage recovers to the normal voltage range and the position feedback signal recovers to normal, it is determined that the fault recovery conditions are met. The variable valve timing system is controlled to adjust the camshaft phase with a preset initial reference phase as the target; when the deviation between the actual phase of the camshaft and the initial reference phase is less than a preset first phase deviation threshold, and the holding time is greater than or equal to a preset holding time threshold, it is determined that the phase reset of the variable valve timing system is complete.

[0044] For example, regarding the temporary delayed P0012 faults (such as loose wiring harness connections or transient abnormal power outages) confirmed by the aforementioned threshold determination, the EMS controller, upon detecting that the power supply voltage and sensor signals meet the self-recovery conditions, immediately outputs a reset drive command to control the variable valve timing actuator to smoothly return the camshaft phase to the factory-set initial reference position (e.g., corresponding to a crankshaft angle of 0° reference phase). The return action response time is set to ≤200ms, and a gradient drive force control strategy is used during the return process to avoid mechanical shocks and abnormal noises caused by sudden phase changes. Simultaneously, the EMS controller monitors the return progress through high-frequency feedback using the camshaft position sensor, with a sampling frequency set to ≥10 times / second. When the deviation between the camshaft phase and the initial reference phase is detected to be stably less than or equal to the first phase deviation ±0.5°, and continuously maintained at the initial reference position for a duration greater than or equal to the holding time threshold of 50ms, it is determined that the variable valve timing system has accurately reached the initial reference phase. At this point, the current position is locked, and a subsequent unlocking preparation command is triggered. This step provides a precise positional basis for subsequent dedicated unlocking operations, effectively preventing unlocking failure or abnormal following due to incomplete return to position, and ensuring that the variable valve timing system restores its normal adjustment capability.

[0045] Furthermore, the release of the locking state of the variable valve timing system locking mechanism specifically includes: outputting an unlocking pulse signal to the locking solenoid valve of the variable valve timing system to perform a single forced unlocking operation on the locking mechanism; updating the locking mechanism status flag to unlocked, and prohibiting the repeated sending of the unlocking pulse signal.

[0046] For example, after the EMS controller determines that the camshaft has accurately reached the initial reference phase, it immediately initiates the newly added dedicated unlocking control logic. The EMS controller outputs a set of pulse drive signals with a fixed timing to the lock-up solenoid valve of the variable valve timing actuator, performing a single forced unlocking operation of the lock-up mechanism. In this embodiment, the unlocking pulse duration is strictly controlled between 100ms and 150ms, and the unlocking drive current matches the rated range of the original vehicle actuator. Through this specific pulse control strategy, the problem of internal lock-up jamming and mechanical engagement after the variable valve timing system returns to its original position can be completely eliminated, ensuring that the lock pin exits smoothly. After unlocking, the EMS built-in status flag is updated to unlocked, and repeated unlocking actions are prohibited to avoid wear on the lock-up mechanism due to excessive movement and to extend the service life of the components. At the same time, the system synchronously wakes up the timing fast follow-up preparatory program, eliminates the root cause of slow response, prepares for the subsequent fast follow-up timing, ensures that the variable valve timing system restores its normal adjustment capability, and achieves complete automatic recovery of the engine valve timing retardation fault.

[0047] Furthermore, after the variable valve timing system is confirmed to be unlocked, the variable valve timing system is controlled to follow the target timing phase. Specifically, the following steps are included: the corresponding timing parameter MAP is found according to the engine speed, load and coolant temperature to obtain the corresponding target timing phase. The timing parameter MAP stores the mapping data between the vehicle engine speed, load and coolant temperature and the corresponding target timing phase.

[0048] Next, the variable valve timing system is controlled to drive the camshaft phase to approach the target timing phase. During this process, the EMS controller skips the conventional step-by-step delay adjustment process, ensuring that the following response delay is ≤150ms. The following process adopts closed-loop proportional regulation, and the phase deviation is monitored in real time by the camshaft position sensor throughout the process, strictly controlling the steady-state timing following deviation within ±1° of the phase correction threshold, and the transient deviation does not exceed ±1.5° of the transient phase threshold.

[0049] The system monitors the deviation between the actual camshaft timing phase and the target timing phase in real time. If the deviation exceeds a preset phase correction threshold and persists for a preset duration threshold, the control parameters of the variable valve timing system are automatically corrected. For example, when the deviation is > ±1° and lasts > 100ms, automatic fine-tuning correction is triggered with a correction step size ≤ 0.5° until the actual timing phase reaches the target timing phase. The entire rapid follow-up cycle is controlled within ≤ 300ms, ensuring no lag or overshoot throughout, thereby completely eliminating the recurrence of variable valve timing follow-up faults and engine valve timing retardation faults, and restoring the engine to its optimal operating state.

[0050] In a preferred embodiment, after controlling the variable valve timing system to follow the target timing phase, a fault recovery and state closed-loop verification step is also included. Specifically, the EMS controller enters a continuous fault recovery verification process, setting the verification cycle to 1 second / time. Simultaneously, it verifies whether the power supply voltage is within the normal voltage range, whether the position feedback signal from the camshaft position sensor is uninterrupted, and whether the timing phase deviation is less than a preset second deviation threshold.

[0051] In one optional setting of this embodiment, the normal voltage range is the normal operating range of 11.5V to 12.5V, the second deviation threshold is ±1°, and no response hysteresis is required.

[0052] If multiple consecutive checks meet the above threshold conditions, the temporary fault is considered completely eliminated. In this embodiment, if there are no abnormalities after 10 consecutive checks, the temporary P0012 fault code and frozen frame data are automatically cleared, the engine limp-home mode is unlocked, but the permanent fault triggering permission is retained, allowing the vehicle to resume normal operation with full power and full functionality without manual code clearing or repair.

[0053] If the temporary fault threshold is triggered again during the verification period, it is determined that the camshaft timing retardation fault has occurred again during the verification period. The variable valve timing system reset and locking mechanism unlocking operations are automatically repeated, that is, the reset-unlock-follow process is re-executed to achieve fault self-adaptation and self-healing. Through the above closed-loop verification mechanism, this application ensures the reliability of fault recovery. Normal control strategy is only restored after the fault is confirmed to be completely eliminated, effectively preventing fault recurrence.

[0054] In a preferred embodiment, the automatic recovery method for engine valve timing retardation fault further includes a retry count limitation step.

[0055] Specifically, the EMS controller counts the cumulative number of reset operations performed by the variable valve timing system. If the cumulative number exceeds a preset threshold, the reset operation is stopped, and the fault type is updated to a permanent hardware fault. The threshold can be set according to engine operating conditions. For example, it can be set to 3 times, meaning that if the system fails the closed-loop status verification after three consecutive reset-unlock-follow cycles, it is considered an automatic recovery failure. In this case, the EMS controller no longer attempts automatic recovery but instead triggers the engine limp-home mode and stores the fault code according to the permanent hardware fault handling logic, reminding the driver to have it inspected.

[0056] By setting a limit on the number of retry attempts, this application can prevent the system from getting stuck in an infinite reset loop in an unrecoverable fault state, preventing actuator wear, locking mechanism damage, or excessive battery consumption caused by frequent reset operations. At the same time, it ensures that the system will switch to the safety protection process in a timely manner when automatic recovery fails, thus protecting the engine hardware safety and the reliability of system operation.

[0057] The automatic recovery method for engine valve timing retardation faults provided in this application optimizes the diagnostic processing logic of the EMS controller, which can accurately distinguish between temporary wiring harness faults and permanent hardware faults. It cancels the triggering of the engine limp home mode only for temporary faults that are not hardware damage, thus preventing the vehicle from entering a power-limited state for no reason due to loose wiring or momentary power loss, and effectively ensuring the normal driving experience and power performance of the vehicle.

[0058] Secondly, this application introduces a new variable valve timing reset and unlock logic, fundamentally resolving the lock-up issue after return to the original position. Through a control strategy of resetting before unlocking, coupled with a strategy of quickly following the target timing phase, the variable valve timing system rapidly restores its normal adjustment capability, achieving self-recovery from the fault without manual inspection or clearing of fault codes, significantly reducing maintenance costs.

[0059] This application is implemented entirely through software logic optimization, requiring no additional hardware costs and making it easy to promote and apply in existing vehicle models. Through the above technical solution, this application maximizes vehicle operating efficiency and driving experience while ensuring engine hardware safety.

[0060] Secondly, embodiments of this application also provide an automatic recovery device for engine valve timing retardation faults.

[0061] In one embodiment, reference is made to Figure 2 , Figure 2 This is a functional module diagram of an embodiment of the automatic recovery device for engine valve timing retardation fault according to this application. Figure 2 As shown, the automatic recovery device for engine valve timing retardation fault includes: The acquisition module is used to acquire the operating status parameters of the variable valve timing system when a camshaft timing retardation fault is detected in the variable valve timing system and its locking mechanism is locked. The determination module is used to determine the fault type based on the matching result between the operating status parameters and preset fault conditions; A shielding module is used to shield the triggering of the engine degradation protection mode if the fault type is a temporary fault. The control module is used to control the variable valve timing system to perform a phase reset operation when the fault recovery conditions are met, and to release the locking state of its locking mechanism after the reset is completed, and to control the variable valve timing system to follow the target timing phase.

[0062] Furthermore, in one embodiment, the device further includes a detection module, which is used to: If the timing retardation angle of the detected camshaft is greater than a preset first angle threshold, or the response delay of the variable valve timing system is greater than a preset delay duration threshold, then the camshaft timing retardation fault is determined to exist.

[0063] Furthermore, in one embodiment, the operating state parameters of the variable valve timing system include at least one of the following: The position feedback signal of the variable valve timing sensor, the power supply voltage of the variable valve timing actuator, and the connection status of the circuit; The variable valve timing sensor includes a camshaft position sensor, and the position feedback signal includes the camshaft timing phase signal.

[0064] Furthermore, in one embodiment, the determining module is further configured to: If the power supply voltage drops to less than or equal to a preset first voltage threshold and the drop duration is less than or equal to a preset drop duration threshold, and the single interruption duration of the position feedback signal of the variable valve timing sensor is less than or equal to a preset interruption duration threshold, and the power supply voltage and the position feedback signal recover to normal on their own within a preset monitoring time, then the fault type is determined to be a temporary fault. Alternatively, if the power supply voltage is less than or equal to the first voltage threshold and the duration is greater than the drop duration threshold, or the position feedback signal is continuously interrupted for a duration greater than the interruption duration threshold, or the timing retardation angle of the camshaft is greater than a preset second angle threshold, then the fault type is determined to be a permanent hardware fault.

[0065] Furthermore, in one embodiment, the control module is also used for: Once the power supply voltage and the position feedback signal return to normal, the variable valve timing system is controlled to adjust the camshaft phase with a preset initial reference phase as the target. When the deviation between the actual phase of the camshaft and the initial reference phase is less than a preset first phase deviation threshold, and the holding time is greater than or equal to a preset holding time threshold, the phase reset of the variable valve timing system is determined to be complete.

[0066] Furthermore, in one embodiment, the control module is also used for: Output an unlocking pulse signal to the lock-up solenoid valve of the variable valve timing system to perform a single forced unlocking operation on the lock-up mechanism; Update the locking mechanism status flag to unlocked and prevent repeated transmission of the unlock pulse signal.

[0067] Furthermore, in one embodiment, the control module is also used for: The corresponding timing parameter MAP is found based on the engine speed, load and water temperature to obtain the corresponding target timing phase; The corresponding timing parameter MAP is found based on the engine speed, load and water temperature to obtain the corresponding target timing phase; The variable valve timing system is controlled to drive the camshaft in a phase that approximates the target timing phase. The deviation between the actual timing phase of the camshaft and the target timing phase is monitored in real time. If the deviation is greater than a preset phase correction threshold and the duration is greater than a preset duration threshold, the control parameters of the variable valve timing system are automatically corrected until the actual timing phase reaches the target timing phase.

[0068] Furthermore, in one embodiment, the control module is also used for: Within multiple consecutive cycles, it is verified whether the power supply voltage is within the normal voltage range, whether the position feedback signal is not interrupted, and whether the timing phase deviation is less than a preset second deviation threshold. If so, clear the fault code for the camshaft timing retardation fault and disable the engine degradation protection mode. Otherwise, if the camshaft timing retardation fault occurs again during the verification period, the variable valve timing system reset and locking mechanism unlocking operation will be re-executed.

[0069] Furthermore, in one embodiment, the device further includes a statistics module, which is used for: Count the number of times the variable valve timing system performs a reset operation; If the cumulative number of attempts exceeds a preset threshold, the reset operation will be stopped, and the fault type will be updated to a permanent hardware fault.

[0070] Furthermore, in one embodiment, the control module is also used for: If the fault type is a permanent hardware fault, the engine degrade protection mode is activated, the fault code of the camshaft timing retardation fault is stored, and a fault alarm is issued.

[0071] The functions of each module in the above-mentioned automatic recovery device for engine valve timing retardation fault correspond to the steps in the above-mentioned automatic recovery method embodiment for engine valve timing retardation fault, and their functions and implementation processes will not be described in detail here.

[0072] Thirdly, embodiments of this application provide an automatic recovery device for engine valve timing retardation faults. The automatic recovery device for engine valve timing retardation faults can be a device with data processing functions, such as an engine management system controller.

[0073] Reference Figure 3 , Figure 3 This is a schematic diagram of the hardware structure of the automatic recovery device for engine valve timing retardation faults involved in the embodiments of this application. In the embodiments of this application, the automatic recovery device for engine valve timing retardation faults may include a processor, a memory, a communication interface, and a communication bus.

[0074] The communication bus can be of any type and is used to interconnect the processor, memory, and communication interface.

[0075] The communication interface includes input / output (I / O) interfaces, physical interfaces, and logical interfaces used for interconnecting internal components of the automatic recovery device for engine valve timing retardation faults, as well as interfaces for interconnecting the automatic recovery device for engine valve timing retardation faults with other devices (such as other computing devices or user equipment). Physical interfaces can be Ethernet interfaces, fiber optic interfaces, ATM interfaces, etc.; user equipment can be displays, keyboards, etc.

[0076] Memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0077] The processor can be a general-purpose processor, which can call the automatic recovery program for engine valve timing retardation fault stored in memory and execute the automatic recovery method for engine valve timing retardation fault provided in the embodiments of this application. For example, the general-purpose processor can be a central processing unit (CPU). The method executed when the automatic recovery program for engine valve timing retardation fault is called can refer to the various embodiments of the automatic recovery method for engine valve timing retardation fault of this application, and will not be repeated here.

[0078] Those skilled in the art will understand that Figure 3 The hardware structure shown does not constitute a limitation of this application and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0079] It should be noted that the sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0080] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus. The terms "first," "second," and "third," etc., are used to distinguish different objects, etc., and do not indicate a sequence, nor do they limit "first," "second," and "third" to different types.

[0081] In the description of the embodiments of this application, terms such as "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a concrete manner.

[0082] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.

[0083] In some processes described in the embodiments of this application, multiple operations or steps are included in a specific order. However, it should be understood that these operations or steps may not be executed in the order they appear in the embodiments of this application, or they may be executed in parallel. The sequence number of the operation is only used to distinguish different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed sequentially or in parallel, and these operations or steps may be combined.

[0084] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device to execute the methods described in the various embodiments of this application.

[0085] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. An automatic recovery method for engine valve timing retardation fault, characterized in that, The automatic recovery method for engine valve timing retardation fault includes: When a camshaft timing retardation fault is detected in the variable valve timing system and its locking mechanism is locked, the operating status parameters of the variable valve timing system are acquired. The fault type is determined based on the matching result between the operating status parameters and the preset fault conditions; If the fault type is a temporary fault, then the triggering of the engine degradation protection mode will be disabled; When the fault recovery conditions are met, the variable valve timing system is controlled to perform a phase reset operation, and after the reset is completed, the locking state of its locking mechanism is released, and the variable valve timing system is controlled to follow the target timing phase.

2. The automatic recovery method for engine valve timing retardation fault as described in claim 1, characterized in that, Detecting for camshaft timing retardation faults includes: If the timing retardation angle of the detected camshaft is greater than a preset first angle threshold, or the response delay of the variable valve timing system is greater than a preset delay duration threshold, then the camshaft timing retardation fault is determined to exist.

3. The automatic recovery method for engine valve timing retardation fault as described in claim 1, characterized in that, The operating status parameters of the variable valve timing system include at least one of the following: The position feedback signal of the variable valve timing sensor, the power supply voltage of the variable valve timing actuator, and the connection status of the circuit; The variable valve timing sensor includes a camshaft position sensor, and the position feedback signal includes the camshaft timing phase signal.

4. The automatic recovery method for engine valve timing retardation fault as described in claim 3, characterized in that, The step of determining the fault type based on the matching result between the operating status parameters and preset fault conditions includes: If the power supply voltage drops to less than or equal to a preset first voltage threshold and the drop duration is less than or equal to a preset drop duration threshold, and the single interruption duration of the position feedback signal of the variable valve timing sensor is less than or equal to a preset interruption duration threshold, and the power supply voltage and the position feedback signal recover to normal on their own within a preset monitoring time, then the fault type is determined to be a temporary fault. Alternatively, if the power supply voltage is less than or equal to the first voltage threshold and the duration is greater than the drop duration threshold, or the position feedback signal is continuously interrupted for a duration greater than the interruption duration threshold, or the timing retardation angle of the camshaft is greater than a preset second angle threshold, then the fault type is determined to be a permanent hardware fault.

5. The automatic recovery method for engine valve timing retardation fault as described in claim 3, characterized in that, When the fault recovery conditions are met, the variable valve timing system is controlled to perform a phase reset operation, including: Once the power supply voltage and the position feedback signal return to normal, the variable valve timing system is controlled to adjust the camshaft phase with a preset initial reference phase as the target. When the deviation between the actual phase of the camshaft and the initial reference phase is less than a preset first phase deviation threshold, and the holding time is greater than or equal to a preset holding time threshold, the phase reset of the variable valve timing system is determined to be complete.

6. The automatic recovery method for engine valve timing retardation fault as described in claim 1, characterized in that, The release of the locking state of the variable valve timing system locking mechanism includes: Output an unlocking pulse signal to the lock-up solenoid valve of the variable valve timing system to perform a single forced unlocking operation on the lock-up mechanism; Update the locking mechanism status flag to unlocked and prevent repeated transmission of the unlock pulse signal.

7. The automatic recovery method for engine valve timing retardation fault as described in claim 1, characterized in that, The control of the variable valve timing system to follow the target timing phase includes: The corresponding timing parameter MAP is found based on the engine speed, load, and water temperature to obtain the corresponding target timing phase; The variable valve timing system is controlled to drive the camshaft in a phase that approximates the target timing phase. The deviation between the actual timing phase of the camshaft and the target timing phase is monitored in real time. If the deviation is greater than a preset phase correction threshold and the duration is greater than a preset duration threshold, the control parameters of the variable valve timing system are automatically corrected until the actual timing phase reaches the target timing phase.

8. The automatic recovery method for engine valve timing retardation fault as described in any one of claims 1 or 7, characterized in that, After controlling the variable valve timing system to follow the target timing phase, the system further includes: Within multiple consecutive cycles, it is verified whether the power supply voltage is within the normal voltage range, whether the position feedback signal is not interrupted, and whether the timing phase deviation is less than a preset second deviation threshold. If so, clear the fault code for the camshaft timing retardation fault and disable the engine degradation protection mode. Otherwise, if the camshaft timing retardation fault occurs again during the verification period, the variable valve timing system reset and locking mechanism unlocking operation will be re-executed.

9. The automatic recovery method for engine valve timing retardation fault as described in claim 1, characterized in that, The method also includes: Count the number of times the variable valve timing system performs a reset operation; If the cumulative number of attempts exceeds a preset threshold, the reset operation will be stopped, and the fault type will be updated to a permanent hardware fault.

10. The automatic recovery method for engine valve timing retardation fault as described in claim 1, characterized in that, The method also includes: If the fault type is a permanent hardware fault, the engine degrade protection mode is activated, the fault code of the camshaft timing retardation fault is stored, and a fault alarm is issued.

11. An automatic recovery device for engine valve timing retardation fault, characterized in that, The automatic recovery control device for the engine door timing retardation fault includes: The acquisition module is used to acquire the operating status parameters of the variable valve timing system when a camshaft timing retardation fault is detected in the variable valve timing system and its locking mechanism is locked. The determination module is used to determine the fault type based on the matching result between the operating status parameters and preset fault conditions; A shielding module is used to shield the triggering of the engine degradation protection mode if the fault type is a temporary fault. The control module is used to control the variable valve timing system to perform a phase reset operation when the fault recovery conditions are met, and to release the locking state of its locking mechanism after the reset is completed, and to control the variable valve timing system to follow the target timing phase.

12. An automatic recovery device for engine valve timing retardation fault, characterized in that, The automatic recovery device for engine valve timing retardation fault includes a processor, a memory, and an automatic recovery program for engine valve timing retardation fault stored in the memory and executable by the processor, wherein when the automatic recovery program for engine valve timing retardation fault is executed by the processor, it implements the steps of the automatic recovery method for engine valve timing retardation fault as described in any one of claims 1 to 10.

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