A hybrid fuel evaporation control method, device, equipment and medium

Abstract

The application relates to a hybrid fuel evaporation control method, device, equipment and medium. The state signals of a fuel evaporation system are collected, and the current operation condition type is determined. The state signals include carbon can adsorption amount, oil tank pressure and isolation valve position feedback. The operation condition type includes driving condition and test condition. The state signals are compared with preset dynamic thresholds to generate a target control strategy containing a carbon can desorption strategy, an oil tank pressure regulation strategy and an isolation valve on-off strategy. The target control strategy is executed, and feedback signals are collected. The target control strategy is corrected according to the feedback signals. Through the full-closed loop control architecture of the collection-threshold comparison-execution-feedback correction, the application realizes fine and self-adaptive active control of the fuel evaporation system, effectively solves the problems of carbon can adsorption saturation and fuel vapor escape exceeding the standard caused by intermittent work of the engine of a hybrid vehicle, and guarantees the evaporation emission compliance of the vehicle in the whole operation condition and whole life cycle.

Description

Technical Field

[0001] This application relates to the field of hybrid electric vehicle technology, and in particular to a hybrid fuel evaporation control method, device, equipment and medium. Background Technology

[0002] With the continued increase in the market penetration of hybrid electric vehicles, fuel evaporative emission control has become one of the core technological challenges in meeting increasingly stringent emission regulations. Unlike traditional gasoline vehicles, hybrid vehicles have a pure electric driving mode, which means the engine is not continuously running. This leads to a significant narrowing of the operating window and a substantial reduction in desorption opportunities for the fuel evaporative emission control system, which relies on the engine's intake negative pressure. At the same time, regulations are increasingly stringent regarding the escape from the rear of the charcoal canister, the sealing and pressure maintenance of the fuel tank, and the accuracy of OBD monitoring. These requirements place far higher technical demands on the evaporative emission control capabilities of hybrid vehicles across all operating conditions and throughout their entire lifecycle compared to traditional vehicles.

[0003] In related technologies, fuel evaporation control schemes for hybrid vehicles typically trigger charcoal canister desorption based on preset fixed time or mileage thresholds. Fuel tank pressure regulation relies on the unidirectional passive opening and closing of mechanical valves, while the isolation valve is controlled uniformly under all operating conditions according to a single logic. However, these schemes have several inherent drawbacks. First, in usage scenarios where pure electric driving accounts for a high proportion, prolonged engine inactivity leads to a severely insufficient desorption window, causing the charcoal canister to easily accumulate to saturation, resulting in fuel vapor penetrating the charcoal canister bed and escaping into the atmosphere. Second, fuel tank pressure exhibits complex dynamic fluctuations due to factors such as diurnal temperature variations, fuel consumption, and altitude changes. Fixed thresholds or purely mechanical adjustment methods suffer from lag and insufficient precision, especially under high-temperature hot-immersion conditions, which can easily lead to overpressure release from the fuel tank. Furthermore, a timing misalignment often occurs between the desorption process and the engine's operating state, leading to continuous micro-vapor leakage during non-desorption phases due to inaccurate sealing timing of the isolation valve. Summary of the Invention

[0004] This application provides a hybrid fuel evaporation control method, device, equipment, and medium to solve the problem of insufficient accuracy, adaptability, and coordination of the fuel evaporation control system in hybrid vehicles under all operating conditions due to intermittent engine operation.

[0005] In a first aspect, embodiments of this application provide a hybrid fuel evaporation control method, comprising the following steps: Collect the status signals of the fuel evaporation system and determine the current operating condition type. The status signals include at least the carbon canister adsorption amount, fuel tank pressure and isolation valve position feedback. The current operating condition type includes at least driving condition and test condition. Based on the current operating condition type, the status signal is compared with a preset dynamic threshold to generate a target control strategy. The target control strategy includes at least one of the following: a carbon canister desorption strategy, an oil tank pressure regulation strategy, and an isolation valve on / off strategy. The target control strategy is executed to drive the actuators of the fuel evaporation system to operate, and feedback signals are collected after execution. The target control strategy is modified based on the feedback signal.

[0006] In conjunction with the first aspect, in one embodiment, the test conditions include at least the BETP test condition, the normal temperature long-term immersion test condition, the WLTC driving desorption test condition, and the high temperature hot immersion test condition, and each test condition is provided with different dynamic thresholds and target control strategies.

[0007] In conjunction with the first aspect, in one implementation, the target control strategy is generated by comparing the status signal with a preset dynamic threshold based on the current operating condition type. A multi-level adsorption capacity threshold is preset, which includes at least a safety threshold, a warning threshold, a saturation threshold, and a saturation protection threshold. If the current operating condition is driving, the carbon canister desorption strategy includes: If the adsorption capacity of the carbon canister is within the safety threshold, maintain routine monitoring. If the adsorption capacity of the carbon canister is within the warning threshold range, control the vehicle to switch to hybrid mode; If the adsorption capacity of the carbon canister reaches the saturation threshold, the engine is forcibly started to desorb the carbon. If the adsorption capacity of the carbon canister reaches the saturation protection threshold, the driving time in pure electric mode of the vehicle will be limited. During the desorption process, the cumulative desorption amount is calculated in real time. If the cumulative desorption amount reaches the preset ratio threshold of the adsorption amount of the carbon canister at the start of desorption, the desorption is determined to be complete and the current desorption process is terminated.

[0008] In conjunction with the first aspect, in one implementation, the target control strategy is generated by comparing the status signal with a preset dynamic threshold based on the current operating condition type. A multi-level oil tank pressure threshold is preset, which includes at least the full-range pressure control range, the normal safe pressure stabilization range, the pressure holding test locking threshold range, the high pressure relief threshold, the low pressure gas replenishment threshold, and the emergency pressure relief threshold. If the current operating condition is driving, the fuel tank pressure regulation strategy includes: If the tank pressure deviates from the normal safe pressure range and fails to return to the normal safe pressure range for a preset time, a pressure regulation control command is generated to adjust the tank pressure back to the normal safe pressure range.

[0009] In conjunction with the first aspect, in one implementation, generating a pressure regulation control command to restore the tank pressure to the normal safe pressure range includes: If the tank pressure is higher than the high pressure relief threshold, the control actuator will release pressure at a preset relief rate until the pressure returns to the preset high pressure target range. If the oil tank pressure is lower than the low-pressure air replenishment threshold, the control actuator replenishes air at a preset air replenishment rate until the pressure returns to the preset low-pressure target range. The preset pressure relief rate and the preset air replenishment rate are adaptively adjusted according to the degree of pressure deviation.

[0010] In conjunction with the first aspect, in one implementation, the target control strategy is generated by comparing the status signal with a preset dynamic threshold based on the current operating condition type. If the current operating condition is driving, generate an isolation valve on / off strategy, including: Under non-desorption conditions, the isolation valve is closed. During desorption, the isolation valve is opened and the engine is started.

[0011] In conjunction with the first aspect, in one embodiment, under the BETP test conditions, the target control strategy includes: controlling the adsorption amount of the carbon canister to not exceed the safety threshold, controlling the leakage of the isolation valve seal to not exceed a first preset value, and controlling the isolation valve to maintain a sealed state.

[0012] In conjunction with the first aspect, in one embodiment, under the normal temperature long-term immersion condition, the target control strategy includes: controlling the oil tank pressure within the normal safe pressure range, and controlling the isolation valve to remain in a sealed state.

[0013] In conjunction with the first aspect, in one implementation, under the WLTC driving desorption condition, the target control strategy includes: performing dynamic desorption by matching cyclic conditions, and the desorption efficiency is not lower than a preset efficiency value.

[0014] In conjunction with the first aspect, in one embodiment, under the high-temperature hot immersion condition, the target control strategy includes: controlling the oil tank pressure to a first preset range, and after the hot immersion is completed, in response to the next vehicle start command, controlling the engine to start and opening the charcoal canister cleaning valve to perform an additional desorption process to reduce the charcoal canister adsorption load.

[0015] In conjunction with the first aspect, in one implementation, the operating condition type further includes a fault operating condition, and determining the current operating condition type as a fault operating condition includes: Monitor the desorption efficiency of the carbon canister, the accuracy of pressure regulation, and the operational status of the isolation valve; When any of the relevant performance parameters of the charcoal canister, pressure-related performance parameters, or isolation valve action parameters exceed the corresponding preset fault judgment conditions, the fault level is determined, the current operating condition type is marked as a fault condition, and the corresponding fault level is determined according to the degree of deviation.

[0016] In conjunction with the first aspect, in one implementation, the fault level includes at least a level one fault, a level two fault, and a level three fault; If the fault level is determined to be a Level 1 fault, the target control strategy includes adjusting the dynamic threshold or control duration within the safety compensation range; If the fault level is determined to be a level two fault, the target control strategy includes at least one of limiting the pure electric mode driving time, forcibly increasing the desorption frequency, or reducing the pressure deviation threshold that triggers pressure regulation. If the fault level is determined to be a level three fault, the target control strategy includes locking the evaporation system and illuminating the fault indicator light.

[0017] In conjunction with the first aspect, in one implementation, the method further includes a lifecycle parameter update strategy: Real-time acquisition and recording of long-term decay data on carbon canister desorption efficiency, oil tank pressure regulation accuracy, and isolation valve sealing leakage; Based on the long-term attenuation data, update the baseline parameters in the preset dynamic threshold, or adjust the sealing compensation parameters; When hardware performance degrades beyond a preset threshold, a maintenance warning signal is generated.

[0018] In conjunction with the first aspect, in one implementation, the method further includes a multi-module interlocking strategy: When the adsorption capacity of the charcoal canister exceeds the standard, the engine power mode is switched and forced to desorb, locking the fuel tank pressure within the safe range. When the tank pressure is abnormal, the adaptive pressure regulation correction is triggered to limit the instantaneous desorption flow of the carbon canister and seal the isolation valve; When the isolation valve seal is abnormal, the locking and desorption action is activated, and the pressure redundancy maintenance and backup seal are started.

[0019] In conjunction with the first aspect, in one embodiment, the feedback signal includes at least one of the following: the actual position signal of the actuator, the pipeline pressure change signal, the engine intake air flow signal, or the charcoal canister temperature change signal; The adaptive correction of the control parameters in the target control strategy based on the feedback signal includes: If the deviation between the feedback signal and the expected target value exceeds the allowable range, the dynamic threshold is adjusted or the action intensity of the actuator is increased.

[0020] Secondly, embodiments of this application provide a hybrid fuel evaporation control device, comprising: The signal acquisition module is used to acquire the status signals of the fuel evaporation system and determine the current operating condition. The strategy generation module is used to compare the status signal with a preset dynamic threshold according to the current operating condition type, and generate a target control strategy. An execution control module is used to execute the target control strategy to drive the actuators of the fuel evaporation system. The correction module is used to adaptively correct the control parameters in the target control strategy based on the feedback signal after execution.

[0021] Thirdly, embodiments of this application provide a hybrid fuel evaporation control device, characterized in that the hybrid fuel evaporation control device includes a processor, a memory, and a hybrid fuel evaporation control program stored in the memory and executable by the processor, wherein when the hybrid fuel evaporation control program is executed by the processor, it implements the steps of the hybrid fuel evaporation control method as described in the first aspect.

[0022] Fourthly, embodiments of this application provide a computer-readable storage medium storing a hybrid fuel evaporation control program, wherein when the hybrid fuel evaporation control program is executed by a processor, it implements the steps of the hybrid fuel evaporation control method as described in the first aspect.

[0023] This application provides a hybrid fuel evaporation control method, device, equipment, and medium. By real-time acquisition of multi-dimensional status signals such as charcoal canister adsorption capacity, fuel tank pressure, and isolation valve position feedback, and identification of the current operating condition, the status signals are compared step-by-step with dynamic thresholds that are adaptively adjusted according to operating condition type, environmental conditions, and hardware status. This ensures that the desorption triggering timing, pressure regulation intervention boundary, and isolation valve on / off time are always precisely aligned with the actual physical state of the system. This avoids systemic deviations such as delayed response of fixed thresholds at high temperatures, premature triggering at low temperatures, and control inaccuracies due to hardware aging. Furthermore, feedback signals are continuously collected after execution to perform closed-loop correction of the strategy, giving the dynamic thresholds both "pre-adaptive" and "post-self-corrective" capabilities. Therefore, it achieves refined and proactive intelligent control of the fuel evaporation system under all operating conditions, solving the problems of charcoal canister adsorption saturation, fuel tank pressure runaway, and excessive fuel vapor emission caused by intermittent engine operation in hybrid vehicles, and ensuring the compliance of evaporative emissions throughout the vehicle's entire life cycle. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the hybrid fuel evaporation control method of this application; Figure 2 This is a schematic diagram of the hardware structure of the hybrid fuel evaporation control device involved in the embodiments of this application. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] First, some of the technical terms used in this application will be explained to help those skilled in the art understand this application.

[0028] FTIV: Fuel tank isolation valve; BETP: Onboard Evaporative Emissions Test Procedure; WLTC: Worldwide Light Vehicles Test Cycle; VCU: Vehicle Control Unit.

[0029] 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.

[0030] In a first aspect, embodiments of this application provide a hybrid fuel evaporation control method.

[0031] In one embodiment, reference is made to Figure 1 , Figure 1 This is a schematic flowchart of the first embodiment of the hybrid fuel evaporation control method of this application. Figure 1 As shown, the hybrid fuel evaporation control method includes: Step S1: Collect the status signal of the fuel evaporation system and determine the current operating condition type.

[0032] Specifically, the VCU (Vehicle Control Unit) communicates with various sensors and actuators via the CAN bus, acquiring multi-dimensional status signals of the fuel evaporation system in real time at a uniform sampling frequency of 10Hz. These status signals include at least: charcoal canister adsorption amount (obtained via an HC concentration sensor inside the charcoal canister), fuel tank pressure (acquired via a fuel tank pressure sensor with a measurement accuracy of ±0.5kPa), and isolation valve position feedback (obtained via a position sensor built into the FTIV). In addition, auxiliary signals such as engine operating conditions (speed, load, intake airflow), vehicle operating status (vehicle speed, gear, pure electric / hybrid mode indicator), ambient temperature, and system leakage status can also be acquired. Data transmission delay is controlled within 0.1s to ensure the real-time nature of the data obtained by the decision-making control layer.

[0033] The current operating conditions include at least three types: driving condition, testing condition, and fault condition. Driving and testing conditions represent the normal operating states when the system is fault-free. Driving condition is further subdivided into pure electric driving condition, hybrid driving condition, and stationary parking condition. Testing conditions include BETP testing condition, normal temperature long-term immersion condition, WLTC driving desorption condition, and high-temperature hot immersion condition. Fault condition occurs when the system self-diagnoses and detects an anomaly, classifying it as a Level 1, Level 2, or Level 3 fault based on the diagnostic results.

[0034] Operating condition type identification can be achieved in several ways: for example, by comprehensively judging whether the vehicle is currently in pure electric driving or hybrid driving by combining the vehicle gear signal, vehicle speed signal and engine start / stop status; by identifying whether the vehicle has entered BETP test mode by receiving signals from external test equipment through the on-board diagnostic interface; and by determining whether there is a fault and the fault level by the fault codes output by the system self-diagnostic module.

[0035] For example, suppose a hybrid vehicle is driving on urban roads with the engine off and the vehicle powered solely by electric drive. The Vehicle Control Unit (VCU) reads in real-time via the CAN bus that the charcoal canister adsorption level is 65% (within the warning threshold range), the fuel tank pressure is +8 kPa (within the normal safe pressure range), the FTIV valve position feedback is "closed," the vehicle speed is 45 km / h, the engine speed is 0, and the vehicle operating mode is identified as "pure electric mode." The VCU, by combining these signals, determines the current operating condition as "pure electric driving condition."

[0036] Step S2: Based on the current operating condition type, compare the status signal with the preset dynamic threshold to generate the target control strategy.

[0037] Specifically, the VCU has multiple pre-stored dynamic threshold parameter templates for different operating conditions. After step S1 determines the current operating condition type, the VCU calls the threshold template that matches the operating condition type, compares the real-time collected status signals with the thresholds at each level in the template, and generates the corresponding target control strategy based on the comparison results.

[0038] The target control strategy includes at least one of the following: charcoal canister desorption strategy, fuel tank pressure regulation strategy, and isolation valve on / off strategy. These three strategies are not necessarily generated all at once, but rather generated as needed based on the current operating condition and the comparison results between the status signal and the threshold. For example, when driving in pure electric mode and the charcoal canister adsorption level has not reached the warning threshold, only the isolation valve on / off strategy (keeping it closed) may be generated; while when the charcoal canister adsorption level reaches the saturation threshold, the charcoal canister desorption strategy (forced engine start for desorption), the fuel tank pressure regulation strategy (pressure stabilization), and the isolation valve on / off strategy (opening) need to be generated simultaneously.

[0039] The concept of dynamic thresholds refers to the fact that thresholds at each level are not fixed constants, but can be dynamically adjusted according to factors such as operating conditions, ambient temperature, and hardware aging. For example, in high-temperature environments, the safety threshold can be appropriately lowered to reserve more adsorption margin; after hardware aging, the saturation protection threshold can be appropriately lowered to trigger intervention earlier.

[0040] Continuing the previous example, the current driving condition is pure electric, and the charcoal canister adsorption capacity is 65%. The VCU calls the driving condition threshold template for comparison: safety threshold ≤ 60%, warning threshold 60%~80%, saturation threshold ≥ 80%, and saturation protection threshold ≥ 85%. 65% is within the warning threshold range, therefore, the target control strategy is generated: the charcoal canister desorption strategy is "flexibly switch to hybrid mode and start the engine for desorption"; the fuel tank pressure regulation strategy is "current pressure is normal, maintain monitoring"; and the isolation valve on / off strategy is "synchronously open FTIV after the engine starts". At the same time, the VCU calculates that desorption is complete when the cumulative desorption capacity reaches 95% of the current adsorption capacity.

[0041] Step S3: Execute the target control strategy, drive the actuators of the fuel evaporation system to operate, and collect the feedback signal after execution.

[0042] Specifically, the VCU converts the target control strategy generated in step S2 into specific execution instructions and sends them to the corresponding actuators via the CAN bus. The actuators mainly include: the charcoal canister cleaning valve (controlling the on / off state and opening degree of the desorption pipeline), the fuel tank isolation valve FTIV (controlling the on / off state of the steam passage from the fuel tank to the charcoal canister), and the engine control unit EMS (controlling engine start / stop and operating parameters), etc.

[0043] While driving the actuator to move, the VCU continuously collects feedback signals after execution. Feedback signals include, but are not limited to: the actual position signal of the actuator (such as the actual opening degree of FTIV, the actual opening degree of the charcoal canister cleaning valve), the pipeline pressure change signal (pressure fluctuation in the desorption pipeline), the engine intake air flow signal (used to calculate the actual desorption flow rate), and the charcoal canister temperature change signal (the desorption process is accompanied by heat absorption, and the temperature change can reflect the desorption intensity).

[0044] The sampling frequency of the feedback signal is kept consistent with that of the status signal, both being 10Hz, to ensure the real-time nature of the feedback data. The VCU compares the feedback signal with the expected target value in real time. If the deviation is found to exceed the allowable range, the correction mechanism in step S4 is triggered.

[0045] Continuing the previous example, the VCU sends an engine start request to the EMS and simultaneously sends an opening command to the FTIV (requiring opening within 0.3 seconds and an opening stroke of 6 mm). The EMS starts the engine and stabilizes it at 1750 r / min. The FTIV feedback signal shows that the engine has opened to 6.2 mm within 0.25 seconds (the deviation is within the allowable range). The charcoal canister cleaning valve adjusts its opening according to the required desorption flow rate of 5~8 L / min. The VCU calculates the actual desorption flow rate in real time as 6.5 L / min using the engine intake air flow signal and pipeline pressure change signal. At the same time, it monitors the charcoal canister temperature dropping from 25℃ to 22℃ (desorption endothermic effect), indicating that the desorption process is proceeding normally. The VCU accumulates the desorption amount, and when the accumulated desorption amount reaches 95% of the adsorption amount (i.e., 61.75%), desorption is considered complete.

[0046] Step S4: Correct the target control strategy based on the feedback signal.

[0047] Specifically, the VCU calculates the deviation between the feedback signal acquired in step S3 and the corresponding expected target value. If the deviation is within the allowable range, the current control strategy is maintained; if the deviation exceeds the allowable range, an adaptive correction mechanism is triggered.

[0048] Correction methods include, but are not limited to: adjusting the dynamic threshold (e.g., lowering the safety threshold from 60% to 55% to trigger intervention earlier), increasing the intensity of the actuator's action (e.g., increasing the opening of the carbon canister cleaning valve to increase the desorption flow rate), extending or shortening the control duration (e.g., extending the desorption time to compensate for insufficient desorption efficiency), and adjusting the pressure regulation rate parameters.

[0049] The correction process is dynamic and iterative; that is, after each correction, feedback signals are collected for verification until the deviation returns to the allowable range or the safety protection limit is reached. This closed-loop mechanism of "collection-execution-verification-correction" ensures that the execution effect of the control strategy always remains consistent with the design expectations.

[0050] Suppose that during the desorption process, the VCU calculates the actual desorption flow rate using the engine intake airflow signal and finds it to be only 3.5 L / min, lower than the preset range of 5-8 L / min. The VCU determines that the deviation exceeds the allowable range and triggers adaptive correction: gradually increasing the opening command of the charcoal canister cleaning valve while monitoring the feedback flow rate change. When the opening command increases to 120% of the original command, the feedback flow rate recovers to 5.8 L / min, and the VCU records this correction parameter and maintains the current command. If a similar deviation occurs again under the same operating conditions in subsequent operations, the VCU can directly call the corrected parameters without needing to iterate again, thereby improving response speed.

[0051] By constructing a fully closed-loop control chain of "signal acquisition - operating condition identification - dynamic threshold comparison - strategy generation and execution - feedback correction," refined and adaptive active control of the fuel evaporation system is achieved. Because this method abandons the traditional open-loop fixed logic control approach, it can differentiate and coordinate the three core control measures—carbon canister desorption, fuel tank pressure stabilization, and isolation valve sealing—based on the quantitative comparison results of real-time status signals and preset dynamic thresholds, according to the unique pure electric driving, hybrid driving, and various test conditions of hybrid vehicles. Simultaneously, it continuously optimizes control actions using a closed-loop correction mechanism composed of feedback signals. This effectively solves the problems of carbon canister adsorption saturation and excessive fuel vapor emission caused by coarse control logic, poor operating condition adaptability, and unquantifiable parameters in related technologies. It improves the response speed and control accuracy of the fuel evaporation control system under all operating conditions and enhances the evaporative emission compliance of the vehicle throughout its entire lifecycle.

[0052] Furthermore, in one embodiment, the test conditions include at least the BETP test condition, the normal temperature long-term immersion test condition, the WLTC driving desorption test condition, and the high temperature hot immersion test condition, and each test condition is equipped with different dynamic thresholds and target control strategies.

[0053] Specifically, the China VII emission regulations clearly stipulate multiple evaporative emission test procedures, each with different requirements for the state of the fuel evaporative system. This application configures dedicated dynamic threshold parameter templates and target control strategies for the four core regulatory operating conditions. The system automatically calls the corresponding threshold template and control strategy by identifying the current test condition.

[0054] BETP Test Condition: This test aims to measure the evaporative emissions of a vehicle during a 48-hour immersion process. Under this condition, the system must strictly control the adsorption capacity of the charcoal canister within a safe threshold. The FTIV process must be fully sealed, with a system leakage rate of ≤0.001g / h, ensuring that the charcoal canister has sufficient adsorption capacity to capture fuel vapors generated during the test and preventing reverse escape exceeding the limit.

[0055] Long-term immersion at normal temperature: This applies to vehicles that have been parked at normal temperature for an extended period (6-36 hours). The system locks the fuel tank pressure within the normal safe pressure range, maintains a long-term seal with FTIV, and only operates in silent monitoring mode to ensure that pressure fluctuations caused by day-night temperature differences do not cause fuel vapor to penetrate the sealing layer and escape.

[0056] WLTC Driving Desorption Condition: This condition corresponds to the vehicle undergoing WLTC cycle desorption on a chassis dynamometer. The system matches the engine operating window in the cycle condition, dynamically adjusting the desorption timing and intensity to ensure a desorption efficiency of ≥95% and a desorption energy consumption of ≤0.5kWh throughout the entire test cycle, meeting the China VII electric balance regulations.

[0057] High-temperature hot soaking condition: This corresponds to the evaporative emission test after the vehicle has been hot-soaked in a high-temperature environment (35℃~40℃) for 1 hour. The system strengthens and stabilizes the fuel tank pressure to the 10~15kPa range to strictly control micro-leakage. After the hot soaking is completed, in response to the vehicle's next start command, the engine is automatically started and the charcoal canister cleaning valve is opened to perform an additional desorption process to remove the adsorption load increased during the hot soaking.

[0058] For example, when a vehicle enters the laboratory for BETP testing, the testing equipment sends a "BETP test mode" identifier to the VCU via the OBD interface. Upon recognizing this identifier, the VCU immediately invokes the BETP-specific threshold template: the charcoal canister safety threshold is lowered from 60% to 50%, the FTIV seal leakage control target is tightened from 0.005 g / h to 0.001 g / h, and all temporary commands that might trigger desorption are blocked. During the 48-hour test, the VCU continuously monitors changes in charcoal canister adsorption to ensure it never exceeds the 50% safety threshold.

[0059] In this embodiment, by configuring dedicated dynamic threshold parameter templates and target control strategies for the four core regulatory conditions of China VII, the system can automatically identify and accurately adapt to regulatory requirements in all scenarios such as BETP testing, long-term vehicle immersion, WLTC driving, and high-temperature heat immersion. This solves the technical defects in related technologies where a single control logic cannot adapt to the needs of multiple operating conditions, resulting in emissions exceeding the standard under specific test conditions. It fully meets the China VII regulations' requirements for the full-dimensional and full-scenario control of evaporative emissions from hybrid vehicles.

[0060] Furthermore, in one embodiment, the process of comparing the status signal with a preset dynamic threshold based on the current operating condition type to generate a target control strategy includes: A multi-level adsorption threshold is preset, which includes at least a safety threshold, a warning threshold, a saturation threshold, and a saturation protection threshold.

[0061] Specifically, the adsorption capacity of the charcoal canister is expressed as a percentage, reflecting the proportion of fuel vapor currently adsorbed by the charcoal canister to its total adsorption capacity. The setting of the four threshold levels follows the principle of "early warning, graded intervention, and progressively stricter measures": the safety threshold (e.g., ≤60%) indicates that the system is in a safe state and no intervention is required; the warning threshold (e.g., 60%~80%) indicates that the adsorption capacity has reached a moderate level and early intervention is required to avoid entering a high-risk range; the saturation threshold (e.g., ≥80%) indicates that the adsorption capacity is close to saturation and mandatory intervention is necessary to prevent penetration; the saturation protection threshold (e.g., ≥85%) indicates that the system is in a critical state and restrictive measures must be taken to ensure safety.

[0062] If the current operating condition is driving, the carbon canister desorption strategy includes: (1) If the adsorption capacity of the carbon canister is within the safe threshold, maintain routine monitoring.

[0063] Specifically, at this point, the charcoal canister adsorption capacity is sufficient, the system has no desorption requirement, and the VCU only maintains routine monitoring of the adsorption capacity without triggering any active intervention. In this state, the FTIV remains closed, the fuel tank maintains natural pressure fluctuations, and the engine starts and stops normally according to driving needs, without being started additionally due to evaporation control requirements.

[0064] (2) If the adsorption capacity of the carbon canister is within the warning threshold range, control the vehicle to switch to hybrid mode.

[0065] Specifically, when the adsorption capacity of the charcoal canister reaches the warning threshold range, the system predicts that it will reach saturation within a foreseeable time if no intervention is taken. At this point, a flexible intervention method is adopted, requesting the vehicle to switch from pure electric mode to hybrid mode through the HCU (Hybrid Vehicle Control Unit). The desorption is completed incidentally by taking advantage of the engine's working opportunity in hybrid mode, without the need to start the engine separately, thus taking into account both energy economy and evaporation control requirements.

[0066] For example, when the vehicle is driving in pure electric mode, the charcoal canister adsorption level gradually rises to 65%. The VCU determines that it has entered the warning threshold range and sends a "request to switch to hybrid mode" command to the HCU. After assessing the current driving conditions, the HCU starts the engine at the next appropriate time (such as when the vehicle's acceleration demand increases), and the vehicle switches to hybrid driving mode. After the engine starts, the VCU simultaneously opens the FTIV and charcoal canister cleaning valve, using the engine intake negative pressure to perform desorption. The entire process is imperceptible to the driver.

[0067] (3) If the adsorption capacity of the carbon canister reaches the saturation threshold, the engine is forcibly started to desorb.

[0068] Specifically, when the adsorption amount reaches the saturation threshold, it indicates that the flexible intervention has missed its opportunity or is insufficient, and mandatory measures must be taken. The VCU directly sends a forced engine start request to the EMS, prioritizing desorption regardless of the current driving mode. After engine start, it operates stably in the 1500~2000 r / min range, with torque fluctuations controlled within ±5 N·m, ensuring both desorption effectiveness and smoothness. The desorption flow rate is controlled at 5~8 L / min, with a desorbed fuel ratio of 10%~15%, reducing the adsorption amount below the safe threshold within 30~60 minutes.

[0069] For example, if a vehicle is operating in pure electric mode and the engine has not been started for several days, the charcoal canister adsorption capacity may reach 82%. The VCU (Vehicle Control Unit) determines that the saturation threshold has been reached and immediately sends a forced start request to the EMS (Electrical Maintenance System). The EMS starts the engine and stabilizes it at 1800 rpm, while the VCU simultaneously opens the FTIV (Fixed-Induction Volt) and charcoal canister cleaning valve. Desorption continues, and the VCU calculates the cumulative desorption amount in real time. After approximately 45 minutes, the adsorption capacity drops to 55%, indicating that desorption is complete. Upon receiving the instruction, the EMS stops the engine, and the vehicle resumes pure electric operation.

[0070] (4) If the adsorption capacity of the carbon canister reaches the saturation protection threshold, the driving time of the vehicle in pure electric mode will be limited.

[0071] Specifically, when the adsorption amount reaches the saturation protection threshold, it indicates that the system is in a critical state. At this point, simple forced desorption is insufficient to quickly reduce the risk, and measures need to be taken simultaneously from the perspective of "source reduction". The VCU limits the pure electric driving time of the vehicle through the HCU, forcing the vehicle to switch to hybrid mode in a shorter period of time, increasing the engine's operating opportunities to accelerate the regeneration of the carbon canister, and preventing the adsorption amount from rising further to the penetration point due to continuous pure electric driving.

[0072] For example, when the vehicle is driving in pure electric mode, the charcoal canister adsorption level has reached 86% (exceeding the saturation protection threshold of 85%). The VCU determines that it has entered a critical state. On the one hand, it immediately starts the engine to force desorption, and on the other hand, it sends a "limit pure electric driving time" command to the HCU. After the HCU responds, it adjusts the allowed continuous pure electric driving time from unlimited to no more than 15 minutes. After the time limit expires, it automatically switches to hybrid mode to ensure that the charcoal canister has sufficient desorption opportunity.

[0073] (5) During the desorption process, the cumulative desorption amount is calculated in real time. If the cumulative desorption amount reaches the preset ratio threshold of the carbon canister adsorption amount at the start of desorption, the desorption is determined to be completed and the current desorption process is terminated.

[0074] Specifically, the desorption process is not simply a continuous fixed duration, but rather employs a precise control logic of "quantitative desorption". The VCU calculates the cumulative desorption amount in real time based on the desorption flow rate and desorption time. When the cumulative desorption amount reaches a preset ratio of the adsorption amount before desorption (such as 95%), the desorption is deemed qualified, and the desorption process is actively terminated to avoid energy waste caused by excessive desorption.

[0075] In this embodiment, a four-level quantitative standard is set for the adsorption capacity of the carbon canister, including a safety threshold, a warning threshold, a saturation threshold, and a saturation protection threshold. The adsorption capacity is accumulated in real time according to different operating conditions such as hybrid pure electric stationary, pure electric driving, and hybrid driving. Flexible desorption or forced high-efficiency desorption is triggered as needed. At the same time, the desorption completion node is determined by the quantitative desorption capacity. This solves the common industry problems in related technologies, such as arbitrary desorption timing, uncontrollable desorption degree, and easy reverse escape of BETP carbon canister due to adsorption saturation. It realizes refined and threshold-based closed-loop control of the entire adsorption-desorption process of the carbon canister.

[0076] Furthermore, in one embodiment, the process of comparing the status signal with a preset dynamic threshold based on the current operating condition type to generate a target control strategy includes: The system presets multiple oil tank pressure thresholds, which include at least the full-range pressure control range, the normal safety pressure stabilization range, the pressure holding test lock-in threshold range, the high-pressure relief threshold, the low-pressure gas replenishment threshold, and the emergency relief threshold.

[0077] Specifically, the fuel tank experiences positive or negative pressure fluctuations due to factors such as diurnal temperature variations and fuel consumption. The multi-stage fuel tank pressure threshold settings ensure the system can execute differentiated control strategies under different pressure conditions: the full-range pressure control range defines the maximum pressure range the system can safely withstand (e.g., -15kPa to 35kPa); the normal safe pressure stabilization range defines the desired pressure stability range during daily driving (e.g., -5kPa to 15kPa); the pressure holding test locking threshold range is used for precise locking targets during China VII high-pressure pressure holding tests (e.g., 35±0.5kPa); the high-pressure relief threshold and low-pressure replenishment threshold define the pressure boundaries that trigger active pressure relief or replenishment actions, respectively; and the emergency relief threshold serves as the final mechanical safety valve trigger boundary.

[0078] If the current operating condition is driving, the fuel tank pressure regulation strategy includes: If the oil tank pressure deviates from the normal safe pressure range and fails to return to the normal safe pressure range for a preset time, a pressure regulation control command is generated to adjust the oil tank pressure back to the normal safe pressure range.

[0079] Specifically, fuel tank pressure may fluctuate briefly during driving due to factors such as fuel sloshing and temperature changes. Not all deviations require immediate intervention. The system is set to continuously judge for a period of time (e.g., 5 seconds). If the pressure deviates from the normal safe pressure range and does not automatically return to normal within this time, it is determined that active intervention is required, and a corresponding pressure regulation control command is generated.

[0080] For example, when a vehicle is driving in high summer temperatures, the internal pressure of the fuel tank rises to +16 kPa due to heat radiation, exceeding the upper limit of the normal safe pressure stabilization range (+15 kPa). The VCU detects this deviation and starts timing. After 5 seconds, the pressure remains at +16.2 kPa and does not automatically return to normal. The VCU determines that active intervention is needed, generates a pressure relief control command, and releases pressure at a rate of 2.5 kPa / s until the pressure returns to +12 kPa (within the high-pressure target range of 10~15 kPa). Then, the pressure relief stops and normal monitoring resumes.

[0081] In this embodiment, a multi-level fuel tank pressure threshold system is established, which includes a preset full-range pressure control range, a normal safe pressure stabilization range, a pressure holding test locking threshold range, high and low pressure correction thresholds, and an emergency pressure relief threshold. This system enables differentiated control across multiple scenarios, including adaptive pressure stabilization under normal operating conditions, precise pressure locking under regulatory testing conditions, and rapid correction and redundant protection for abnormal pressure. It solves the technical defects in related technologies, such as low fuel tank pressure control accuracy, poor pressure holding capacity, and delayed response to abnormal pressure leading to micro-leakage of fuel vapor. This significantly improves the pressure stabilization capability and robustness of the fuel tank sealing system.

[0082] Furthermore, in one embodiment, generating a pressure regulation control command to restore the tank pressure to a normal safe and stable pressure range includes: If the oil tank pressure is higher than the high pressure relief threshold, the control actuator will release the pressure at a preset relief rate until the pressure returns to the preset high pressure target range. If the oil tank pressure is lower than the low-pressure air replenishment threshold, the control actuator replenishes air at a preset air replenishment rate until the pressure returns to the preset low-pressure target range. The preset pressure relief rate and preset air replenishment rate are adaptively adjusted according to the degree of pressure deviation.

[0083] Specifically, depressurization and air replenishment are achieved by controlling the opening of the FTIV and coordinating it with the charcoal canister cleaning valve. During depressurization, the FTIV is opened to guide the steam from the tank into the charcoal canister for adsorption; during air replenishment, filtered fresh air is introduced into the tank through the charcoal canister cleaning valve to replenish the pressure.

[0084] The depressurization rate and gas replenishment rate are not fixed values, but are adaptively adjusted according to the degree to which the current pressure deviates from the target. When the deviation is large, a faster rate is used to quickly eliminate the risk; when the deviation is close to the target range, the rate is reduced to avoid overshoot. This variable parameter adjustment method balances response speed and control accuracy.

[0085] In this embodiment, by using a variable parameter adjustment mechanism that adaptively adjusts the pressure relief rate and the air replenishment rate according to the degree of pressure deviation, the problem of fixed pressure regulation rate, easy pressure overshoot or excessively long adjustment time in related technologies is solved. This achieves the optimal balance between speed and accuracy in the oil tank pressure regulation process, further improving the system's response quality and pressure stabilization efficiency.

[0086] Furthermore, in one embodiment, the process of comparing the status signal with a preset dynamic threshold based on the current operating condition type to generate a target control strategy includes: If the current operating condition is driving, generate an isolation valve on / off strategy, including: Under non-desorption conditions, the isolation valve is closed. During desorption, the isolation valve is opened and the engine is started.

[0087] Specifically, the FTIV (Fuel Tank Isolation Valve) is an electrically controlled valve installed on the pipeline between the fuel tank and the charcoal canister. Its state directly determines whether the fuel tank vapor passage is connected to the outside. Under non-desorption conditions (including pure electric driving, stationary parking, BETP testing, etc.), the FTIV remains closed, completely cutting off the vapor passage from the fuel tank to the charcoal canister at a physical level, preventing fuel vapor in the fuel tank from escaping into the charcoal canister and eventually penetrating into the atmosphere when there is no need for desorption. Under desorption conditions, the FTIV is triggered and opened synchronously with engine start-up, ensuring that the desorption negative pressure can be transmitted to the fuel tank, drawing the fuel vapor adsorbed in the charcoal canister to the engine for combustion.

[0088] In this embodiment, by using the on / off logic of the isolation valve being fully closed during non-desorption conditions and precisely open during desorption conditions, the vapor passage of the fuel tank is completely physically cut off during non-necessary periods. This solves the problem of continuous fuel vapor leakage caused by the coarse control logic of the isolation valve and the inaccurate sealing timing in related technologies, and curbs the fugitive emission of VOCs during non-desorption periods from the source.

[0089] Furthermore, in one embodiment, under the BETP test conditions, the target control strategy includes: controlling the adsorption amount of the carbon canister to not exceed a safety threshold, controlling the leakage of the isolation valve seal to not exceed a first preset value, and controlling the isolation valve to maintain a sealed state.

[0090] Specifically, BETP is a stringent evaporative emissions test under the China VII emission standard, requiring vehicles to undergo a 48-hour immersion test to measure HC emissions at the rear end of the charcoal canister. During this test, the charcoal canister must maintain sufficient adsorption margin at all times to capture all fuel vapors generated in the fuel tank during the test; FTIV must remain highly sealed throughout the entire process to prevent any external air from entering the fuel tank through the FTIV, causing pressure fluctuations or vapor leakage.

[0091] The first preset value is typically set to 0.001 g / h, requiring the FTIV to maintain near-zero leakage sealing performance throughout the 48-hour test. To achieve this goal, the system not only shuts down the FTIV in BETP test mode, but also ensures a sealing torque ≥5 N·m by increasing the sealing drive current or mechanical locking mechanism, and blocks all commands that might trigger temporary opening of the FTIV (such as active pressure relief requests triggered by excessive pressure).

[0092] For example, once the vehicle enters BETP test mode, the VCU immediately lowers the charcoal canister safety threshold from 60% to 50% and sends feedback to the test equipment via the OBD interface that the system is ready. During the first 48 hours of testing, the VCU monitors the charcoal canister adsorption capacity every minute to ensure it remains ≤50%. Simultaneously, it monitors the FTIV seal leakage. When an upward trend in leakage is detected (e.g., from 0.0005 g / h to 0.0008 g / h), the VCU automatically increases the FTIV seal drive current to strengthen the seal. Throughout the entire 48-hour test, the FTIV remains closed, unaffected by any temporary commands, and the final system leakage stabilizes at 0.0006 g / h, far exceeding the requirement of 0.001 g / h.

[0093] In this embodiment, by locking the carbon canister adsorption amount within a safe threshold under BETP test conditions, sealing and locking the isolation valve throughout the process, and controlling the system leakage to a preset accuracy level, the core bottleneck problem of the China VII regulations, which is caused by carbon canister adsorption saturation or poor sealing of the isolation valve during BETP testing, is solved. This provides a reliable technical guarantee for hybrid vehicles to pass the China VII BETP test.

[0094] Furthermore, in one embodiment, under the condition of long-term immersion at normal temperature, the target control strategy includes: controlling the oil tank pressure within the normal safe pressure range and controlling the isolation valve to remain sealed.

[0095] Specifically, the long-term immersion condition at normal temperature corresponds to a vehicle being parked at normal temperature (20℃~30℃) for an extended period, typically 6~36 hours. During this period, the temperature difference between day and night causes the gas inside the fuel tank to expand and contract, resulting in periodic positive and negative pressure fluctuations. If the pressure fluctuations exceed the sealing system's capacity, fuel vapor may slowly escape through the micro-leakage channels in the seals.

[0096] Under these operating conditions, the system locks the tank pressure within the normal safe pressure range (-5kPa~15kPa). When the pressure deviates from this range due to temperature changes, it actively performs fine-tuning. Simultaneously, the FTIV maintains a long-term seal, ensuring that the tank vapor passage remains physically shut off during extended periods of inactivity. Throughout the entire process, the system maintains silent monitoring operation, avoiding unnecessary triggering and minimizing energy consumption.

[0097] In this embodiment, by locking the fuel tank pressure within the normal safe pressure range and maintaining the long-term sealing of the isolation valve under the condition of long-term immersion at normal temperature, the technical hidden danger of fuel tank pressure fluctuation and fuel vapor slowly escaping through the sealing layer caused by the diurnal temperature difference during the long-term static parking of hybrid vehicles is solved, thus achieving zero VOCs emission control under the condition of long-term static parking.

[0098] Furthermore, in one embodiment, under WLTC driving desorption conditions, the target control strategy includes: performing dynamic desorption by matching cyclic conditions, and ensuring that the desorption efficiency is not lower than a preset efficiency value.

[0099] Specifically, WLTC is the vehicle emission certification test cycle stipulated by the China VII emission standard, with a total duration of 1800 seconds, including four speed ranges: low speed, medium speed, high speed, and ultra-high speed. Under the WLTC driving desorption condition, the vehicle runs according to the WLTC cycle on a chassis dynamometer, and carbon canister desorption is required to prove the vehicle's evaporative emission control capability during actual driving.

[0100] Because the WLTC cycle includes several periods of low engine intake negative pressure, such as deceleration and idling, blind desorption may lead to low desorption efficiency. This solution uses "dynamic desorption matched to cycle conditions," which intelligently selects the time window with sufficient engine negative pressure and good desorption conditions based on the real-time operating status of the engine in the WLTC cycle (speed, load, intake airflow), avoiding periods of insufficient negative pressure. The preset efficiency value is usually set to 95%, meaning that the amount of fuel vapor desorbed in the entire WLTC cycle must reach more than 95% of the amount adsorbed by the charcoal canister before desorption. At the same time, the desorption energy consumption must be ≤0.5kWh, balancing environmental performance and energy economy.

[0101] For example, the vehicle runs the WLTC cycle on a chassis dynamometer, with the VCU monitoring the engine intake negative pressure signal in real time. During the first 200 seconds of the cycle at low speeds, the engine load is low, and the intake negative pressure is insufficient, so the VCU does not initiate desorption. Entering the medium-speed range (200-800 seconds), the engine load increases, and the intake negative pressure stabilizes above -60 kPa, at which point the VCU activates the FTIV and charcoal canister cleaning valve for desorption. Desorption continues into the high-speed range, and reaches its peak efficiency during the ultra-high-speed range when the engine operates under high load. At the end of the cycle, during the deceleration phase, the intake negative pressure decreases, and the VCU shuts off desorption as needed. After the entire cycle, the VCU calculates that the cumulative desorption amount reaches 96.5% of the pre-desorption adsorption amount, and the desorption energy consumption is 0.42 kWh, both meeting the requirements.

[0102] In this embodiment, by matching the cyclic operating conditions under WLTC driving desorption conditions to perform dynamic desorption and ensuring that the desorption efficiency is not lower than the preset efficiency value, the technical problems of low desorption efficiency, excessive desorption energy consumption, and inability to meet the requirements of China VII electric balance regulations in related technologies are solved, and the optimal synergy between desorption performance and vehicle energy consumption is achieved.

[0103] Furthermore, in one embodiment, under high-temperature hot immersion conditions, the target control strategy includes: controlling the oil tank pressure to a first preset range, and after the hot immersion is completed, in response to the next vehicle start command, controlling the engine to start and opening the charcoal canister cleaning valve to perform an additional desorption process to reduce the charcoal canister adsorption load.

[0104] Specifically, the high-temperature hot soaking condition simulates the evaporative emissions of a vehicle parked in a high-temperature environment (35℃~40℃) and subjected to one hour of hot soaking. Under high-temperature conditions, the fuel evaporation rate increases sharply, and the adsorption load of the charcoal canister increases significantly, making it an extreme and challenging condition for evaporative emission control.

[0105] The first preset pressure range is typically set at 10~15 kPa (upwards from the -5~15 kPa range at room temperature). This is because the saturated vapor pressure inside the fuel tank increases at high temperatures, and appropriately increasing the target pressure range helps reduce the total amount of fuel vaporization in the tank, thus reducing the adsorption load on the charcoal canister from the source. After the hot soaking, the temperature inside the fuel tank remains high, and the charcoal canister may have absorbed a large amount of fuel vapor. If the vehicle is started directly and driven purely on electric power at this time, the adsorption capacity of the charcoal canister may be close to saturation. Therefore, the system automatically starts the engine and opens the charcoal canister cleaning valve the next time the vehicle is started, performing an additional desorption process to remove the adsorption load accumulated during the hot soaking, restoring the system to a safe state.

[0106] In this embodiment, by strengthening the pressure stabilization of the fuel tank to a preset range under high-temperature hot immersion conditions, and automatically triggering the carbon canister residual repair and desorption process after the hot immersion is completed, the problem of saturation risk caused by the increased fuel evaporation and sudden increase in carbon canister adsorption load caused by high temperature environment is solved, and the system self-recovery and compliance status maintenance under high temperature extreme conditions are realized.

[0107] Furthermore, in one embodiment, determining that the current operating condition type is a fault condition includes: Monitor the desorption efficiency of the carbon canister, the accuracy of pressure regulation, and the operational status of the isolation valve; When the desorption efficiency or adsorption capacity decay of the carbon canister exceeds the preset value, the pressure deviation exceeds the preset value and the duration exceeds the set time, the pressure regulation response time exceeds the preset time, or the isolation valve action timeout or valve position mismatch occurs, the fault level is determined and the current operating condition type is marked as a fault condition.

[0108] Specifically, the system continuously monitors several key performance indicators during normal control procedures. These indicators reflect the health status of the core components of the fuel evaporation system. The fault diagnosis criteria are designed following the principle of "early detection and accurate location." If the desorption efficiency or adsorption capacity decay of the carbon canister exceeds the preset value (e.g., desorption efficiency < 95% or adsorption capacity decay > 10%), it indicates that the carbon canister may be clogged, broken, or the adsorption material may be aging. If the pressure deviation exceeds the preset value and continues for more than the set time (e.g., pressure deviation > 3 kPa for 5 seconds), it indicates that the pressure sensor or pressure regulating actuator may be faulty. If the voltage regulation response time exceeds the preset duration (e.g., voltage regulation response > 0.3 seconds), it indicates that there is a delay in the actuator or control loop. If the isolation valve timeout or valve position mismatch (e.g., no position feedback within 0.3 seconds after the opening command is issued, or the command value deviates from the actual position by more than 10%), it indicates that the FTIV may be stuck or the drive circuit is abnormal.

[0109] In this embodiment, by real-time monitoring of multiple parameters such as carbon canister desorption efficiency, pressure regulation accuracy, and isolation valve operation status, and by accurately identifying the fault level based on preset fault judgment conditions, the technical problems of delayed fault identification, lack of fault classification, and inability to adapt to the enhanced diagnostic requirements of China VII OBD in related technologies are solved, providing a reliable basis for early detection, accurate location, and rapid handling of system faults.

[0110] Furthermore, in one embodiment, the fault levels include at least Level 1 fault, Level 2 fault, and Level 3 fault.

[0111] The characteristics of a Level 1 fault are as follows: the pressure deviation deviates from the standard range of ±1 to 3 kPa, the duration is less than 5 seconds and the pressure can rebound autonomously; the instantaneous leakage of the system does not exceed 0.005 g / h and does not exceed the near-zero limit of China VII; the FTIV action delay is 0.1 to 0.3 seconds, the valve position feedback has a small fluctuation, there is no jamming or permanent closure failure; the overall fault is an occasional, instantaneous, and self-healing fault with no continuous abnormal signals.

[0112] The characteristics of a Level 2 fault are: pressure deviation from the standard range is greater than or equal to 3 kPa and lasts for more than 5 seconds, unable to rebound on its own, and pressure regulation accuracy decreases; the continuous leakage of the system is between 0.005 and 0.01 g / h, close to the National VII limit; frequent FTIV response deviation, switching accuracy exceeds ±0.1 seconds, occasional incomplete closure but no complete jamming; functionally, it manifests as decreased desorption efficiency and excessive pressure fluctuation, posing a risk of exceeding standards under high-temperature hot immersion and long-term immersion conditions.

[0113] The characteristics of a Level 3 fault are: FTIV valve body jamming and inability to switch on and off normally; wear and failure of the sealing surface; pressure regulating module response timeout greater than 0.3 seconds; system leakage exceeding 0.01 g / h, exceeding the near-zero emission limit of China VII, with significant VOCs escaping; inability to maintain the standard pressure stabilization range, with a 24-hour pressure drop greater than 0.5 kPa, and complete failure of the pressure holding function; and complete incompatibility with BETP testing and long-term pressure holding testing in terms of regulatory risks, with a clear risk of exceeding emission standards.

[0114] The system adopts differentiated graded handling strategies for different fault levels. If the fault level is determined to be a Level 1 fault, the target control strategy includes adjusting the dynamic threshold or control duration within the safety compensation range; If the fault level is determined to be a level 2 fault, the target control strategy includes at least one of the following: limiting the pure electric mode driving time, forcibly increasing the desorption frequency, or reducing the pressure deviation threshold that triggers pressure regulation. If the fault level is determined to be a level three fault, the target control strategy includes locking the evaporation system and illuminating the fault indicator light.

[0115] Specifically, the three-tiered fault classification and handling mechanism provides differentiated response plans based on the severity of the fault: Level 1 Fault (Minor Fault): The system performance is slightly degraded but still retains basic control capabilities. The countermeasure is to adaptively correct the parameters at the software level, such as adjusting the dynamic threshold within the safety compensation range (e.g., lowering the safety threshold from 60% to 55% to leave more safety margin) or extending the control duration (e.g., extending the desorption time by 20% to compensate for the slight decrease in desorption efficiency), without restricting the normal use of the vehicle.

[0116] Level 2 Fault (Moderate Fault): System performance is significantly degraded, and without intervention, it may lead to excessive emissions within a foreseeable timeframe. Countermeasures include limiting pure electric mode driving time (increasing engine operating opportunities), forcibly increasing desorption frequency (shortening the time interval between two desorption events), and reducing the pressure deviation threshold for triggering pressure regulation (improving pressure control sensitivity). The vehicle can still be driven, but the driving experience may be somewhat affected.

[0117] Level 3 Fault (Severe Fault): The system can no longer guarantee basic emission control functions. The solution is to lock the evaporative emission control system (locking the FTIV in the closed position, preventing any desorption action, and ensuring complete isolation of the fuel tank from the outside) and illuminate the malfunction indicator light (the MIL light on the dashboard illuminates, prompting the owner to have the vehicle inspected immediately). The vehicle can still be driven in emergencies, but the evaporative emission control function has been completely taken over by a redundant backup mechanism.

[0118] In this embodiment, a three-level fault classification and handling mechanism is established. For minor faults, software adaptive parameter correction is performed; for moderate faults, the pure electric duration is limited and forced high-frequency desorption is implemented; and for severe faults, the evaporation system is locked down and fault indication is provided. This solves the problems of single fault handling methods, lack of differentiated redundancy fallback schemes, and continuous emission exceeding standards under fault conditions in related technologies. It eliminates the risk of excessive evaporation emissions under fault conditions from the source and fully complies with the regulatory requirements of China VII OBD enhanced diagnosis.

[0119] Furthermore, in one embodiment, the method further includes a lifecycle parameter update strategy: Real-time acquisition and recording of long-term decay data on carbon canister desorption efficiency, oil tank pressure regulation accuracy, and isolation valve sealing leakage; Based on long-term attenuation data, update the baseline parameters in the preset dynamic threshold, or adjust the sealing compensation parameters. When hardware performance degrades beyond a preset threshold, a maintenance warning signal is generated.

[0120] Specifically, the hardware performance of the fuel vaporization system naturally degrades over time: the adsorption material in the charcoal canister gradually becomes saturated and ages, leading to a decrease in adsorption capacity; and the mechanical components of the pressure sensor and FTIV wear down, resulting in reduced accuracy. Without compensation, the originally precise control parameters will gradually deviate from the ideal state, ultimately leading to excessive emissions.

[0121] This solution addresses this issue through full lifecycle monitoring and adaptive correction: the system records time-series data of key performance indicators such as charcoal canister desorption efficiency, fuel tank pressure regulation accuracy, and FTIV seal leakage at fixed intervals (e.g., every 5000 kilometers). Based on this long-term degradation data, the system employs a trend prediction algorithm to estimate performance degradation trends and dynamically adjusts control parameters accordingly. For example, when a linear downward trend in charcoal canister desorption efficiency is detected, the system gradually increases the target desorption flow rate or extends the desorption time to compensate for efficiency loss. When an upward trend in FTIV seal leakage is detected, the system automatically increases the seal drive current to strengthen the seal. When hardware performance degradation exceeds a preset safety threshold, the system generates a maintenance warning signal, prompting the owner or repair personnel to replace the relevant components.

[0122] For example, when a vehicle has traveled 60,000 kilometers, the system's historical data on the carbon canister desorption efficiency shows: 97% at 10,000 kilometers, 95.5% at 30,000 kilometers, and 94% at 50,000 kilometers. Trend prediction indicates it may drop below 92% at 70,000 kilometers. Based on this trend, at 50,000 kilometers, the system gradually increases the desorption flow rate target from 6 L / min to 7 L / min and extends the desorption time from 30 minutes to 35 minutes to compensate for the efficiency decline. Simultaneously, the system records an increase in FTIV seal leakage from 0.0002 g / h to 0.0008 g / h, automatically increasing the seal drive current by 5%. At 70,000 kilometers, the actual desorption efficiency remains at 94.5%, and the overall system performance remains compliant. When the seal leakage further increases to 0.002 g / h, the system generates a maintenance warning signal recommending replacement of the FTIV seal assembly.

[0123] In this embodiment, by collecting and recording long-term decay data of carbon canister desorption efficiency, fuel tank pressure regulation accuracy, and isolation valve sealing leakage in real time, and adaptively updating the benchmark parameters in the dynamic threshold or adjusting the sealing compensation parameters accordingly, the common industry problem of control accuracy decay and emission performance deterioration due to hardware aging in related technologies, without effective countermeasures, is solved. Closed-loop stability of evaporative emission control accuracy is achieved throughout the vehicle's entire life cycle, significantly extending the system's compliant service life.

[0124] Furthermore, in one embodiment, the method further includes a multi-module interlocking strategy: When the adsorption capacity of the charcoal canister exceeds the standard, the engine power mode is switched and forced to desorb, locking the fuel tank pressure within the safe range. When the tank pressure is abnormal, the adaptive pressure regulation correction is triggered to limit the instantaneous desorption flow of the carbon canister and seal the isolation valve; When the isolation valve seal is abnormal, the locking and desorption action is activated, and the pressure redundancy maintenance and backup seal are started.

[0125] Specifically, the three modules—charcoal canister, oil tank pressure, and FTIV—do not operate independently, but rather achieve information sharing and coordinated control through the VCU. When one module malfunctions, the other modules automatically enter a coordinated protection state, forming an interlock mechanism. (1) When the adsorption capacity of the carbon canister exceeds the standard: it indicates that the carbon canister is close to saturation and desorption is urgently needed. The system switches the engine power mode (forces the engine to start) and performs desorption, while locking the oil tank pressure within a safe range (locking the oil tank pressure control target within a safe window to avoid increasing the extra adsorption load of the carbon canister due to oil tank pressure fluctuations), ensuring that the desorption process proceeds smoothly.

[0126] (2) Abnormal oil tank pressure: This indicates a possible problem with the pressure regulating system. The system will first trigger adaptive pressure regulation correction (increase the pressure regulating intensity), while limiting the instantaneous desorption flow rate of the charcoal canister (because high-flow desorption will cause drastic pressure fluctuations in the oil tank, so the desorption rate needs to be reduced to minimize the impact on the oil tank pressure), and strengthen the seal through FTIV (closing the FTIV isolates the oil tank from the charcoal canister to prevent oil tank pressure fluctuations from affecting the charcoal canister's condition). After the pressure returns to normal, normal control will be gradually restored.

[0127] (3) FTIV seal malfunction: This indicates that the FTIV may be stuck or leaking. The system immediately locks the desorption action (prohibits any commands that may require the FTIV to open), starts pressure redundancy pressure maintenance (maintains stable tank pressure through other means), triggers the backup seal (if a backup seal mechanism is available, it is put into use), and triggers the fault warning. After the fault is repaired, the system resets the entire system control logic.

[0128] For example, when the vehicle is operating in pure electric mode, the charcoal canister adsorption capacity reaches 82% (exceeding the standard), while the fuel tank pressure rises to +18 kPa (abnormal) due to the high temperature environment. The VCU (Vehicle Control Unit) activates an interlock mechanism: on one hand, it sends a forced engine start request to the EMS (Electronic Management System) and initiates FTIV (Fixed-Flush Induction) to perform desorption, locking the fuel tank pressure control target within the 10-15 kPa range; on the other hand, due to the abnormal fuel tank pressure, it limits the charcoal canister desorption flow rate from the preset 6 L / min to 3 L / min to prevent further disturbance to the fuel tank pressure from high-flow desorption. Once the fuel tank pressure returns to +12 kPa under adaptive pressure correction, the VCU releases the desorption flow rate restriction, restoring the desorption flow rate to 6 L / min, and desorption continues until the charcoal canister adsorption capacity drops below 60%. Throughout the entire process, the two modules work in concert without any loss of control.

[0129] In this embodiment, by constructing a full-domain linkage and interlocking mechanism for the three major modules of charcoal canister, fuel tank, and isolation valve, the coordinated protection action of the other modules is automatically triggered when any module is in an abnormal state. This solves the safety hazards of independent operation of each control module, lack of coordinated backup scheme in abnormal state, and easy chain failure in related technologies. It forms a full-chain safety protection system of "perception-decision-execution-interlock-backup", which greatly improves the fault tolerance and system robustness of the fuel evaporation control system under complex operating conditions.

[0130] Furthermore, in one embodiment, the feedback signal includes at least one of the following: the actual position signal of the actuator, the pipeline pressure change signal, the engine intake air flow signal, or the charcoal canister temperature change signal; Adaptive adjustments are made to the control parameters in the target control strategy based on feedback signals, including: If the deviation between the feedback signal and the expected target value exceeds the allowable range, adjust the dynamic threshold or increase the action intensity of the actuator.

[0131] Specifically, the core of closed-loop control lies in the continuous operation of the "feedback-comparison-correction" mechanism. The more types and higher accuracy of feedback signals collected by the system, the better the quality of the closed-loop control. The actual position signal of the actuator (such as the actual opening degree of FTIV, the actual opening degree of the carbon canister cleaning valve): is used to verify whether the actuator operates according to the expected command. Deviation may be caused by jamming, insufficient drive current, etc. Pipeline pressure change signal: Used to verify whether the pressure in the desorption pipeline is within the expected range. Deviation may be caused by pipeline blockage, leakage, etc. Engine intake air flow signal: used to calculate the actual desorption flow rate and compare it with the theoretical flow rate estimated based on valve opening. The deviation may be caused by factors such as changes in intake system resistance. Temperature change signal of carbon canister: The desorption process is accompanied by an endothermic effect, and the temperature change can indirectly reflect the desorption intensity. Deviation may be caused by abnormal internal structure of the carbon canister.

[0132] When any feedback signal deviates from the expected target value beyond the allowable range, the system initiates adaptive correction. There are two main correction methods: adjusting the dynamic threshold (e.g., lowering the safety threshold from 60% to 55% to compensate for canister capacity decay) or increasing the intensity of actuator actions (e.g., increasing the canister cleaning valve opening to increase desorption flow). The correction process is iterative, with feedback signals collected after each correction to verify the effect, until the deviation returns to the allowable range.

[0133] For example, during desorption, the VCU calculates the actual desorption flow rate as 4.2 L / min based on the engine intake air flow signal, while the theoretical flow rate estimated based on the current opening of the charcoal canister cleaning valve should be 6 L / min, a deviation of 30%, far exceeding the allowable range (±10%). The VCU initiates adaptive correction: gradually increasing the charcoal canister cleaning valve opening command by 5% each time, while monitoring the feedback flow rate change. When the opening command increases from the current value to 130%, the feedback flow rate rises to 5.8 L / min, and the deviation decreases to 3.3%, entering the allowable range. The VCU records the corrected opening-flow mapping relationship, and the corrected parameters are directly used under subsequent operating conditions, significantly improving the response speed. Simultaneously, the VCU records the deviation phenomenon of "actual flow rate lower than theoretical flow rate" in the long-term degradation database as a reference for judging the degree of blockage in the charcoal canister or pipeline.

[0134] In this embodiment, multi-dimensional feedback signals such as the actual position of the actuator, pipeline pressure changes, engine intake air flow, and charcoal canister temperature are collected and compared with the expected target values. When the deviation exceeds the allowable range, the dynamic threshold is adaptively adjusted or the actuator action intensity is increased. This solves the technical defects of open-loop control in related technologies, which cannot detect execution deviations and whose control accuracy deteriorates with changes in operating conditions. It forms a complete control closed loop of "acquisition-execution-verification-correction", ensuring that the execution effect of the control strategy is always consistent with the design expectation.

[0135] Secondly, embodiments of this application also provide a hybrid fuel evaporation control device comprising: The signal acquisition module is used to acquire the status signals of the fuel evaporation system and determine the current operating condition. The strategy generation module is used to compare the status signal with the preset dynamic threshold according to the current operating condition type and generate the target control strategy. The execution control module is used to execute the target control strategy to drive the actuators of the fuel evaporation system. The correction module is used to adaptively correct the control parameters in the target control strategy based on the feedback signal after execution.

[0136] The functions of each module in the above-mentioned hybrid fuel evaporation control device correspond to the steps in the above-mentioned hybrid fuel evaporation control method embodiment, and their functions and implementation processes will not be described in detail here.

[0137] Thirdly, embodiments of this application provide a hybrid fuel evaporation control device, the hybrid fuel evaporation control device including a processor, a memory, and a hybrid fuel evaporation control program stored in the memory and executable by the processor, wherein when the hybrid fuel evaporation control program is executed by the processor, it implements the steps of the hybrid fuel evaporation control method as described in the first aspect.

[0138] Hybrid fuel evaporation control equipment can be a device with data processing capabilities, such as a vehicle control unit (VCU), engine control unit (ECU), or on-board terminal.

[0139] The communication bus can be of any type and is used to interconnect the processor, memory, and communication interface.

[0140] The communication interface includes input / output (I / O) interfaces, physical interfaces, and logical interfaces used for interconnecting components within the hybrid fuel evaporation control device, as well as interfaces used for interconnecting the hybrid fuel evaporation control device 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.

[0141] 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.

[0142] The processor can be a general-purpose processor, which can call the hybrid fuel evaporation control program stored in the memory and execute the hybrid fuel evaporation control method 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 hybrid fuel evaporation control program is called can be referred to in the various embodiments of the hybrid fuel evaporation control method of this application, and will not be described again here.

[0143] Fourthly, embodiments of this application also provide a computer-readable storage medium.

[0144] The present application provides a computer-readable storage medium storing a hybrid fuel evaporation control program, wherein when the hybrid fuel evaporation control program is executed by a processor, it implements the steps of the hybrid fuel evaporation control method as described above.

[0145] The method implemented when the hybrid fuel evaporation control program is executed can be referred to in various embodiments of the hybrid fuel evaporation control method of this application, and will not be repeated here.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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. A method for controlling fuel evaporation in hybrid systems, characterized in that, Includes the following steps: Collect the status signals of the fuel evaporation system and determine the current operating condition type. The status signals include at least the carbon canister adsorption amount, fuel tank pressure and isolation valve position feedback. The current operating condition type includes at least driving condition and test condition. Based on the current operating condition type, the status signal is compared with a preset dynamic threshold to generate a target control strategy. The target control strategy includes at least one of the following: a carbon canister desorption strategy, an oil tank pressure regulation strategy, and an isolation valve on / off strategy. The target control strategy is executed to drive the actuators of the fuel evaporation system to operate, and feedback signals are collected after execution. The target control strategy is corrected based on the feedback signal.

2. The method according to claim 1, characterized in that, The test conditions include at least the BETP test condition, the normal temperature long-term immersion test condition, the WLTC driving desorption test condition, and the high temperature hot immersion test condition. Each test condition is equipped with different dynamic thresholds and target control strategies.

3. The method according to claim 2, characterized in that, Based on the current operating condition type, the status signal is compared with a preset dynamic threshold to generate a target control strategy, including: A multi-level adsorption capacity threshold is preset, which includes at least a safety threshold, a warning threshold, a saturation threshold, and a saturation protection threshold. If the current operating condition is driving, the carbon canister desorption strategy includes: If the adsorption capacity of the carbon canister is within the safety threshold, maintain routine monitoring. If the adsorption capacity of the carbon canister is within the warning threshold range, control the vehicle to switch to hybrid mode; If the adsorption capacity of the carbon canister reaches the saturation threshold, the engine is forcibly started to desorb the carbon. If the adsorption capacity of the carbon canister reaches the saturation protection threshold, the driving time in pure electric mode of the vehicle will be limited. During the desorption process, the cumulative desorption amount is calculated in real time. If the cumulative desorption amount reaches the preset ratio threshold of the adsorption amount of the carbon canister at the start of desorption, the desorption is determined to be complete and the current desorption process is terminated.

4. The method according to claim 2, characterized in that, Based on the current operating condition type, the status signal is compared with a preset dynamic threshold to generate a target control strategy, including: A multi-level oil tank pressure threshold is preset, which includes at least the full-range pressure control range, the normal safe pressure stabilization range, the pressure holding test locking threshold range, the high pressure relief threshold, the low pressure gas replenishment threshold, and the emergency pressure relief threshold. If the current operating condition is driving, the fuel tank pressure regulation strategy includes: If the tank pressure deviates from the normal safe pressure range and fails to return to the normal safe pressure range for a preset time, a pressure regulation control command is generated to adjust the tank pressure back to the normal safe pressure range.

5. The method according to claim 4, characterized in that, Generating a pressure regulation control command to restore the tank pressure to the normal safe pressure regulation range includes: If the tank pressure is higher than the high pressure relief threshold, the control actuator will release pressure at a preset relief rate until the pressure returns to the preset high pressure target range. If the oil tank pressure is lower than the low-pressure air replenishment threshold, the control actuator replenishes air at a preset air replenishment rate until the pressure returns to the preset low-pressure target range. The preset pressure relief rate and the preset air replenishment rate are adaptively adjusted according to the degree of pressure deviation.

6. The method according to claim 1, characterized in that, Based on the current operating condition type, the status signal is compared with a preset dynamic threshold to generate a target control strategy, including: If the current operating condition is driving, generate an isolation valve on / off strategy, including: Under non-desorption conditions, the isolation valve is closed. During desorption, the isolation valve is opened and the engine is started.

7. The method according to claim 3, characterized in that, Under the BETP test conditions, the target control strategy includes: controlling the adsorption amount of the carbon canister to not exceed the safety threshold, controlling the leakage of the isolation valve seal to not exceed the first preset value, and controlling the isolation valve to maintain a sealed state.

8. The method according to claim 4, characterized in that, Under the condition of long-term immersion at normal temperature, the target control strategy includes: controlling the oil tank pressure within the normal safe pressure range, and controlling the isolation valve to maintain a sealed state.

9. The method according to claim 2, characterized in that, Under the WLTC driving desorption condition, the target control strategy includes: matching the cyclic condition for dynamic desorption, and the desorption efficiency is not lower than the preset efficiency value.

10. The method according to claim 2, characterized in that, Under the high-temperature hot immersion condition, the target control strategy includes: controlling the oil tank pressure to stabilize to the first preset range, and after the hot immersion is completed, in response to the next vehicle start command, controlling the engine to start and opening the charcoal canister cleaning valve to perform an additional desorption process to reduce the charcoal canister adsorption load.

11. The method according to claim 1, characterized in that, The operating condition type also includes fault operating condition, and determining the current operating condition type as fault operating condition includes: Monitor the desorption efficiency of the carbon canister, the accuracy of pressure regulation, and the operational status of the isolation valve; When any of the relevant performance parameters of the charcoal canister, pressure-related performance parameters, or isolation valve action parameters exceed the corresponding preset fault judgment conditions, the fault level is determined, the current operating condition type is marked as a fault condition, and the corresponding fault level is determined according to the degree of deviation.

12. The method according to claim 11, characterized in that, The fault levels include at least Level 1 faults, Level 2 faults, and Level 3 faults; If the fault level is determined to be a Level 1 fault, the target control strategy includes adjusting the dynamic threshold or control duration within the safety compensation range; If the fault level is determined to be a level two fault, the target control strategy includes at least one of limiting the pure electric mode driving time, forcibly increasing the desorption frequency, or reducing the pressure deviation threshold that triggers pressure regulation. If the fault level is determined to be a level three fault, the target control strategy includes locking the evaporation system and illuminating the fault indicator light.

13. The method according to claim 1, characterized in that, The method also includes a lifecycle parameter update strategy: Real-time acquisition and recording of long-term decay data on carbon canister desorption efficiency, oil tank pressure regulation accuracy, and isolation valve sealing leakage; Based on the long-term attenuation data, update the baseline parameters in the preset dynamic threshold, or adjust the sealing compensation parameters; When hardware performance degrades beyond a preset threshold, a maintenance warning signal is generated.

14. The method according to claim 1, characterized in that, The method also includes a multi-module interlocking strategy: When the adsorption capacity of the charcoal canister exceeds the standard, the engine power mode is switched and forced to desorb, locking the fuel tank pressure within the safe range. When the tank pressure is abnormal, the adaptive pressure regulation correction is triggered to limit the instantaneous desorption flow of the carbon canister and seal the isolation valve; When the isolation valve seal is abnormal, the locking and desorption action is activated, and the pressure redundancy maintenance and backup seal are started.

15. The method according to claim 1, characterized in that, The feedback signal includes at least one of the following: the actual position signal of the actuator, the pipeline pressure change signal, the engine intake air flow signal, or the charcoal canister temperature change signal; The adaptive correction of the control parameters in the target control strategy based on the feedback signal includes: If the deviation between the feedback signal and the expected target value exceeds the allowable range, the dynamic threshold is adjusted or the action intensity of the actuator is increased.

16. A hybrid fuel evaporation control device, characterized in that, include: The signal acquisition module is used to acquire the status signals of the fuel evaporation system and determine the current operating condition. The strategy generation module is used to compare the status signal with a preset dynamic threshold according to the current operating condition type, and generate a target control strategy. An execution control module is used to execute the target control strategy to drive the actuators of the fuel evaporation system. The correction module is used to adaptively correct the control parameters in the target control strategy based on the feedback signal after execution.

17. A hybrid fuel evaporation control device, characterized in that, The hybrid fuel evaporation control device includes a processor, a memory, and a hybrid fuel evaporation control program stored in the memory and executable by the processor, wherein when the hybrid fuel evaporation control program is executed by the processor, it implements the steps of the hybrid fuel evaporation control method as described in any one of claims 1 to 15.

18. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a hybrid fuel evaporation control program, wherein when the hybrid fuel evaporation control program is executed by a processor, it implements the steps of the hybrid fuel evaporation control method as described in any one of claims 1 to 15.

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