A control method and system for a range-extender electric vehicle in a reverse drag working condition and a storage medium

Abstract

The application relates to a control method and system for a regenerative electric vehicle in a reverse drag working condition and a storage medium, wherein the method comprises the following steps: in a driving cycle, in response to the existence of a diagnostic item with an I UPR value less than a corresponding preset limit value in an on-board diagnostic system, determining whether the diagnostic item belongs to the reverse drag working condition I UPR promotion type; in response to the diagnostic item belonging to the reverse drag working condition I UPR promotion type, determining a target section from a navigation path planned by an electronic map; in response to the regenerative electric vehicle driving to the target section, and the congestion degree of the target section meeting a second preset condition corresponding to the diagnostic item and an automobile working condition parameter corresponding to the diagnostic item meeting a third preset condition, controlling the range extender of the regenerative electric vehicle to enter the reverse drag working condition. Through the method, the problems of difficult I UPR value promotion of the regenerative electric vehicle and frequent entry into the reverse drag working condition affecting the user driving experience can be solved.

Description

Technical Field

[0001] This application relates to the field of diagnostic technology for range-extended electric vehicles, and in particular to a method, system, and storage medium for controlling the reverse driving condition of a range-extended electric vehicle. Background Technology

[0002] The reverse towing test is a necessary condition for a car to complete some diagnostic items. Diagnostic items that need to be completed under the reverse towing test include Variable Valve Timing (VVT), Exhaust Gas Recirculation (EGR), and oxygen sensor diagnostics. However, range-extended electric vehicles do not have a natural reverse towing test because the range extender of a range-extended electric vehicle only operates intermittently as a power generation unit. Its engine does not directly drive the wheels, so the inertia of the wheels cannot reverse tow the engine.

[0003] To complete the diagnostic project under reverse towing conditions, the range-extended electric vehicle can be actively controlled to enter reverse towing conditions, thereby improving the problem of the lack of control over reverse towing conditions in range-extended electric vehicles.

[0004] However, not all diagnostics will be successful when a car enters the reverse towing mode. If the diagnosis fails, the car will attempt to enter the reverse towing mode again until the maximum number of attempts is reached. After that, the car will not enter the reverse towing mode again in the current driving cycle. This causes the in-use performance ratio (IUPR) of the diagnostic items to decrease instead of increase, making it difficult to meet regulatory requirements. Moreover, frequently controlling the range-extended electric vehicle to enter the reverse towing mode will cause the car's noise, vibration and harshness (NVH) performance to deteriorate, affecting the user's driving experience. Summary of the Invention

[0005] Based on this, a method, system, and storage medium for controlling the reverse towing condition of a range-extended electric vehicle are provided, which can improve the problem of difficulty in increasing the I UPR value of range-extended electric vehicles and the impact of frequent entry into the reverse towing condition on the user's driving experience.

[0006] In a first aspect, this application provides a method for controlling the reverse towing condition of a range-extended electric vehicle, comprising: during a driving cycle, in response to a diagnostic item in the on-board diagnostic system having an IUPR value less than a corresponding preset limit, determining whether the diagnostic item belongs to the IUPR improvement type of the reverse towing condition; in response to the diagnostic item belonging to the IUPR improvement type of the reverse towing condition, determining a target road segment from the navigation path planned by the electronic map, wherein the navigation path is the current movement path of the range-extended electric vehicle, and the target road segment is a road segment whose road parameters ahead of the current position of the range-extended electric vehicle meet a first preset condition; in response to the range-extended electric vehicle driving to the target road segment, and the congestion level of the target road segment meeting a second preset condition corresponding to the diagnostic item and the vehicle operating condition parameters corresponding to the diagnostic item meeting a third preset condition, controlling the range extender of the range-extended electric vehicle to enter the reverse towing condition.

[0007] In conjunction with the first aspect, in the first possible implementation of the first aspect, the road parameters satisfy the first preset conditions, including: the slope of the target road segment is less than or equal to a preset slope threshold; the length of the target road segment is greater than or equal to a preset length threshold; and the curvature of the target road segment is less than or equal to a preset curvature threshold.

[0008] In conjunction with the first possible implementation of the first aspect, in the second possible implementation of the first aspect, the preset slope threshold is 0%.

[0009] In conjunction with the first aspect, in the third possible implementation of the first aspect, after controlling the range extender to enter the reverse towing mode, the method further includes: acquiring vehicle operating parameters corresponding to the diagnostic items in real time; and controlling the range extender to exit the reverse towing mode in response to the vehicle operating parameters not meeting the third preset condition.

[0010] In conjunction with the first aspect, in the fourth possible implementation of the first aspect, after controlling the range extender to enter the reverse towing mode, the method further includes: calculating the duration of the range extender in the reverse towing mode; and controlling the range extender to exit the reverse towing mode in response to the duration reaching a preset duration.

[0011] In conjunction with the first aspect, in the fifth possible implementation of the first aspect, after controlling the range extender to enter the reverse towing mode, the method further includes: receiving the current IUPR numerator count value sent by the engine controller in real time, and determining whether the current IUPR numerator count value has increased compared to the historical IUPR numerator count value; the historical IUPR numerator count value is the IUPR numerator count value sent by the engine controller at the moment the range extender enters the reverse towing mode; in response to the current IUPR numerator count value increasing compared to the historical IUPR numerator count value, controlling the range extender to exit the reverse towing mode.

[0012] In conjunction with the first aspect, in the sixth possible implementation of the first aspect, if the diagnostic item pertains to the oxygen sensor, the vehicle operating parameters include engine parameters and vehicle speed; if the diagnostic item pertains to the VVT / EGR group, the vehicle operating parameters include engine parameters.

[0013] In conjunction with the sixth possible implementation of the first aspect, in the seventh possible implementation of the first aspect, the engine parameters include engine speed, engine coolant temperature, aftertreatment exhaust temperature, intake air temperature, and intake air flow rate.

[0014] Secondly, this application also provides a control system for a range-extended electric vehicle (REEV) in a towing condition, comprising: a type determination module configured to, during a driving cycle, determine whether a diagnostic item with an IUPR value less than a corresponding preset limit exists in the on-board diagnostic system, whether the diagnostic item belongs to the IUPR improvement type for a towing condition; a target road segment determination module configured to, in response to the diagnostic item belonging to the IUPR improvement type for a towing condition, determine a target road segment from a navigation path planned by an electronic map; wherein the navigation path is the current movement path of the REEV, and the target road segment is a road segment whose road parameters ahead of the current position of the REEV meet a first preset condition; and a towing condition control module configured to, in response to the REEV traveling to the target road segment, and the congestion level of the target road segment meeting a second preset condition corresponding to the diagnostic item and the vehicle condition parameters corresponding to the diagnostic item meeting a third preset condition, control the range extender of the REEV to enter the towing condition.

[0015] Thirdly, this application also provides a computer-readable storage medium storing a plurality of instructions adapted for loading by a processor and executing a range-extended electric vehicle reverse-draft control method as described in the first aspect or any of the embodiments of the first aspect.

[0016] In summary, this application provides a method, system, and storage medium for controlling the reverse towing condition of a range-extended electric vehicle. This application imposes strict restrictions on the conditions under which the vehicle enters the reverse towing condition, thus improving the difficulty in increasing the I UPR value of range-extended electric vehicles and addressing the issue of frequent entry into the reverse towing condition affecting the user's driving experience. Firstly, by using restriction condition one—that the I UPR value of the diagnostic item is less than the corresponding preset limit and the diagnostic item belongs to the I UPR improvement type of the reverse towing condition—the application reduces the number of times the range-extended electric vehicle enters the reverse towing condition without necessary diagnostics, thereby improving the problem of frequent entry into the reverse towing condition. Secondly, by using restriction condition two—that the range-extended electric vehicle must first travel to the target road segment, and the congestion level of the target road segment meets the second preset condition corresponding to the diagnostic item, and the vehicle operating parameters corresponding to the diagnostic item meet the third preset condition—the application reduces the occurrence of the vehicle unexpectedly exiting the reverse towing condition due to road factors, while ensuring the effectiveness of the diagnosis after entering the reverse towing condition, increasing the probability of successful diagnosis, increasing the probability of I UPR value improvement, thereby reducing the number of times the vehicle enters the reverse towing condition and improving the user's driving experience.

[0017] In summary, this application addresses the difficulties in increasing the I UPR value of range-extended electric vehicles and the impact of frequent entry into reverse towing conditions on the user's driving experience by restricting range-extended electric vehicles to only enter reverse towing conditions when conditions one and two are met. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating a control method for a range-extended electric vehicle in reverse towing mode, as shown in one embodiment.

[0019] Figure 2 This is a schematic diagram of the control system for a range-extended electric vehicle in reverse towing mode, as shown in one embodiment. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0021] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this application. Therefore, the drawings only show components relevant to this application and are not drawn according to the actual number, shape, and size of components in implementation. In actual implementation, the form, quantity, and proportion of each component can be arbitrarily changed, and the component layout may also be more complex. The structures, proportions, sizes, etc., shown in the accompanying drawings are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the implementation conditions of this application. Therefore, they have no substantial technical significance. Any modification to the structure, change in the proportional relationship, or adjustment of the size, without affecting the effect and purpose that this application can produce, should still fall within the scope of the technical content disclosed in this application. At the same time, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are only for clarity of description and are not intended to limit the scope of implementation of this application. Changes or adjustments in their relative relationships, without substantially changing the technical content, should also be considered within the scope of implementation of this application.

[0022] Driving backwards is a necessary condition for a vehicle to complete some diagnostic tasks. Diagnostic tasks requiring driving backwards include those related to variable valve timing (VVT), exhaust gas recirculation (EGR), and oxygen sensor checks. However, range-extended electric vehicles (REEVs) lack a natural driving backwards condition because their range extender operates intermittently as a generator; the engine does not directly drive the wheels, preventing wheel inertia from effectively dragging the engine. Therefore, REEVs can be actively controlled to enter a driving backwards condition, and diagnostics can be performed under this condition.

[0023] The In-Use Performance Ratio (IUPR) is a key indicator of whether diagnostic procedures have been adequately implemented. A low IUPR value indicates insufficient diagnostic work, leading to ineffective emissions monitoring during actual vehicle operation. This increases pollutant emissions and exacerbates environmental pollution, violating mandatory environmental regulations and potentially triggering stringent scrutiny from regulatory agencies. Consistently failing to meet IUPR standards accumulates negative records, affecting vehicle certification status and even leading to suspension of production or sales permits, along with hefty fines and reputational damage. Therefore, in the control of reverse-draft conditions for range-extended electric vehicles, proactive diagnostic processes must be initiated to ensure consistently compliant IUPR values, guaranteeing regulatory compliance and environmental sustainability.

[0024] However, entering the reverse towing condition does not necessarily complete the diagnosis, because the car may not enter the reverse towing condition in some situations. If the car is blindly controlled to enter the reverse towing condition, it will not only fail to complete the diagnosis and improve the IUPR value, but will also repeatedly enter the reverse towing condition due to diagnosis failure, resulting in the deterioration of NVH performance.

[0025] For example, periodically (every preset mileage or every preset time) controls the range-extended electric vehicle to enter the reverse towing mode. Because the periodic control method mechanically controls the vehicle to enter the reverse towing mode, it does not consider the actual diagnostic needs or the effectiveness of entering the mode. This results in the range-extended electric vehicle frequently entering the reverse towing mode, and even if it frequently enters the reverse towing mode, it is difficult to improve the IUPR value.

[0026] It is evident that current technologies for range-extended electric vehicles (REEVs) still face challenges in improving the IUPR (Input / Output Ratio) and the impact of frequent towing on the user's driving experience. Failure to meet IUPR standards prevents vehicles from meeting regulatory requirements and leads to substantial economic losses. Simultaneously, frequent towing severely impacts user experience and causes economic losses, such as deterioration of NVH (Noise, Vibration, and Harshness) performance and interference with normal driving, and can also damage components. Long-term and frequent towing significantly harms REEVs because the engine experiences additional stress during towing, potentially accelerating wear over time. The rigid connection between the engine and generator requires overcoming resistance during towing, increasing mechanical load and making it prone to fatigue damage. Frequent operating condition switching increases thermal management pressure; if the cooling system is inadequate, thermal fatigue can accelerate seal aging or damage components.

[0027] Compared to gasoline vehicles, towing conditions cause more significant damage to the engine and transmission system of range-extended electric vehicles (REEVs). Therefore, this application aims to reduce the frequency of REEVs entering towing conditions, thereby optimizing the vehicle's NVH performance and protecting its components. Thus, addressing the difficulties in improving the IUPR value of REEVs and the impact of frequent towing conditions on the user's driving experience has become a pressing issue in controlling REEVs' towing conditions.

[0028] The In-Use Performance Ratio (IUPR) is the ratio of the numerator to the denominator. The numerator represents the number of times a diagnostic item meets all diagnostic conditions and successfully triggers a diagnosis. For example, VVT, EGR, and oxygen sensor diagnoses all require completion under reverse towing conditions. The denominator is defined as the number of driving cycles that meet the vehicle's operating conditions. These conditions include: 1) cumulative running time after engine start greater than or equal to 600 seconds or cumulative time after high voltage is applied greater than or equal to 600 seconds; 2) cumulative time at a vehicle speed greater than 40 km / h greater than or equal to 300 seconds; and 3) vehicle idling time greater than or equal to 30 seconds. It should be noted that the driving cycle mentioned later in this application refers to a driving cycle that meets the vehicle's operating conditions. One driving cycle refers to all operational procedures completed from engine start to shutdown, including cold start, warm-up, driving, and parking, which will not be elaborated further below.

[0029] Furthermore, the number of times a range-extended electric vehicle can enter the towing mode control during a single driving cycle is limited. Allowing the vehicle to enter towing mode without restriction would lead to performance degradation such as NVH (noise, vibration, and harshness) and interference with normal driving. For example, during a driving cycle, a towing mode control request is sent to the vehicle controller. The vehicle controller will determine whether the number of towing attempts within each driving cycle has reached the limit. If the number of towing attempts exceeds four, the vehicle controller will no longer respond to towing mode control requests.

[0030] Completing at least one successful diagnostic within a driving cycle is crucial for ensuring an increase in the IUPR numerator count. If the vehicle fails to complete a successful diagnostic by the end of a driving cycle, the IUPR denominator count will increment by one while the numerator count remains unchanged, resulting in a decrease in the IUPR value. However, if the vehicle completes a successful diagnostic by the end of a driving cycle, both the IUPR denominator and numerator counts will increment by one, and since the IUPR value is less than 1, the IUPR value will increase.

[0031] Based on this, in order to minimize the probability of increasing the IUPR value of diagnostic items such as VVT diagnosis, EGR diagnosis, and oxygen sensor diagnosis while reducing the backward dragging condition, this application provides a backward dragging condition control method for range-extended electric vehicles. By strictly limiting the conditions under which the vehicle enters the backward dragging condition, this method improves the problem of difficulty in increasing the IUPR value of range-extended electric vehicles and the impact of frequent backward dragging conditions on the user's driving experience.

[0032] It should be noted that the range-extended electric vehicle reverse towing control method provided in this application can be executed by a reverse towing control device. The reverse towing control device can be any control device in a vehicle capable of implementing the range-extended electric vehicle reverse towing control method of this application, such as a controller, processor, etc. In addition, the reverse towing control device or the reverse towing control device can interact with other devices or equipment in other vehicles and execute the range-extended electric vehicle reverse towing control method proposed in this application.

[0033] refer to Figure 1 This is an embodiment of a control method for a range-extended electric vehicle in reverse towing mode provided in this application. Next, this application will combine... Figure 1 This paper describes the implementation process of the reverse towing control method for a range-extended electric vehicle, using the reverse towing control device as the main actuator. Specifically:

[0034] 110: During a driving cycle, in response to a diagnostic item in the on-board diagnostic system having an I UPR value lower than the corresponding preset limit, determine whether the diagnostic item belongs to the I UPR increase type under the reverse towing condition;

[0035] 120: In response to the diagnostic item belonging to the reverse drag condition I UPR improvement type, the target road segment is determined from the navigation path planned by the electronic map. The navigation path is the current movement path of the range-extended electric vehicle, and the target road segment is the road segment ahead of the current position of the range-extended electric vehicle whose road parameters meet the first preset condition.

[0036] 130: In response to the range-extended electric vehicle traveling to the target road segment, and the congestion level of the target road segment meeting the second preset condition corresponding to the diagnostic item and the vehicle operating parameters corresponding to the diagnostic item meeting the third preset condition, control the range extender of the range-extended electric vehicle to enter the reverse towing mode.

[0037] Regarding step 110, each emission-related diagnostic item in the on-board diagnostic system has a corresponding I UPR value. However, not every I UPR value of any diagnostic item falling below the corresponding preset limit will trigger the subsequent process of determining whether to enter the reverse towing condition. This application only triggers the subsequent process of determining whether to enter the reverse towing condition when there is a diagnostic item in the on-board diagnostic system (OBD) with an I UPR value lower than the corresponding preset limit, and the diagnostic item belongs to the reverse towing condition I UPR enhancement type. This ensures that the reverse towing condition is entered according to actual needs, reducing the number of times the reverse towing condition is entered, and also reducing the probability of the vehicle's I UPR value falling below the preset limit. The aforementioned reverse towing condition I UPR enhancement types include VVT ​​diagnostics, EGR diagnostics, and oxygen sensor diagnostics, etc., all of which need to be completed under reverse towing conditions.

[0038] The aforementioned preset limit can be greater than or equal to the minimum I UPR value stipulated by relevant regulations to ensure that vehicle diagnostics meet regulatory requirements. Furthermore, the preset limit can be reasonably adjusted according to different vehicle models and driving environments to optimize the control strategy under reverse drag conditions, making the control method provided in this application universal and adaptable. Preferably, the preset limit is greater than the minimum I UPR value required by regulations and has a certain margin. This margin can be determined through actual testing, ensuring that the I UPR value of the range-extended electric vehicle meets the requirements of different types of regulations and vehicle models.

[0039] In one possible implementation of step 110, the towing control device receives I UPR values ​​from each group of diagnostics collected by the engine control unit (EMS). The towing control device determines whether the diagnostic item with an I UPR value less than the corresponding preset limit belongs to the I UPR enhancement type under towing conditions. If it does not belong to the type, it means that the I UPR values ​​of the diagnostic items under towing conditions meet the diagnostic requirements. If it does belong to the type, it means that the I UPR values ​​of the diagnostic items under towing conditions do not meet the diagnostic requirements. For example, the preset limit for VVT and EGR groups, which need to be diagnosed under towing conditions, is 0.4, while the preset limit for evaporator system leaks, which do not need to be diagnosed under towing conditions, is 0.26. When the I UPR of VVT group is ≥0.4, the I UPR of EGR group is ≥0.4, the I UPR of oxygen sensor is ≥0.4, and the I UPR of evaporator system leak is <0.26, the I UPR value of evaporator system leak does not meet the requirements. It is determined that evaporator system leak does not belong to the I UPR enhancement type under towing conditions. Therefore, the I UPR values ​​of the diagnostic items of the vehicle under towing conditions meet the diagnostic requirements. When the I UPR of VVT group is <0.4, the I UPR of EGR group is ≥0.4, the I UPR of oxygen sensor is ≥0.4, and the I UPR of evaporator system leak is ≥0.26, the I UPR value of VVT group does not meet the requirements. It is determined that VVT group belongs to the I UPR enhancement type under towing conditions. Therefore, the I UPR values ​​of the diagnostic items of the vehicle under towing conditions do not meet the diagnostic requirements.

[0040] Regarding step 120, this application only controls the range-extended electric vehicle to enter the reverse towing mode on the target road section. The target road section is the road section in front of the current position of the range-extended electric vehicle where the road parameters meet the first preset condition. The target road section is the road section where there are fewer instances of unexpected exit from the reverse towing mode due to road factors.

[0041] When a range-extended electric vehicle enters a towing condition on a target road segment, the probability of its engine resuming fuel injection is relatively low, and the probability of sudden braking is also low. This allows the towing condition to be maintained for a period of time until the numerator count of the I UPR numerator increases. Therefore, this application, by controlling the range-extended electric vehicle to enter a towing condition on the target road segment, can reduce the occurrence of the vehicle unexpectedly exiting the towing condition due to road conditions, improve the probability of successful diagnosis, thereby reducing the number of times the vehicle enters the towing condition (for example, the first entry into the towing condition can increment the numerator count of the I UPR numerator by one, so that after the I UPR equals the corresponding preset limit, the range-extended electric vehicle will not enter the towing condition again in the current driving cycle) and increasing the probability of the I UPR value increasing.

[0042] In one possible implementation of step 120, the reverse drag control device can determine a road segment whose road parameters meet a first preset condition from the navigation path planned in the electronic map as a target road segment. The road parameters include at least one of slope, length, and curvature. For example, the target road segment can be a flat road or a downhill road, a road segment with a sufficiently long length, and / or a road segment with a small curvature. Specifically, the road parameters meeting the first preset condition include: the slope of the target road segment is less than or equal to a preset slope threshold; the length of the target road segment is greater than or equal to a preset length threshold; and the curvature of the target road segment is less than or equal to a preset curvature threshold.

[0043] The preset slope threshold can be 0%, meaning the target road segment is a flat or downhill road. The preset slope threshold, preset length threshold, and preset curvature threshold are obtained through statistical analysis of the slope, length, and curvature of road segments where the range-extended electric vehicle (REEV) has experienced little or no unexpected exit from the towing condition. Specifically, the determination of these thresholds involves collecting historical driving data of the REEV under various road conditions, screening typical road segment samples where unexpected exit from the towing condition has occurred little or no, and then quantitatively analyzing the slope, length, and curvature characteristics of these samples, such as calculating the mean, standard deviation, or setting a probability distribution model to extract the optimal range values. Furthermore, these thresholds can be verified and optimized through simulation and real-vehicle testing to further improve the accuracy and robustness of the control method.

[0044] Regarding step 130, when the range-extended electric vehicle reaches the target road segment, it is not immediately controlled to enter the towing mode. Instead, it is controlled to enter the towing mode only after determining that the congestion level of the target road segment meets the second preset condition corresponding to the diagnostic item and the vehicle operating parameters corresponding to the diagnostic item meet the third preset condition. When the second and third preset conditions are met, it is determined that the vehicle passes the diagnostic validity verification, indicating that the vehicle has a high probability of successfully completing the towing mode at this time. This step can realize the diagnostic validity verification, improve the probability of successful diagnosis, thereby reducing the number of times the vehicle enters the towing mode and increasing the probability of improving the I UPR value.

[0045] In one possible implementation of step 130, different congestion levels for different diagnostic items correspond to different second preset conditions. Congestion levels can be assessed using congestion indices or traffic indices, which are obtained from electronic maps or calculated by the reversing control device. Congestion and traffic indices are dimensionless values ​​that comprehensively reflect the degree of road congestion, calculated based on data such as speed, flow rate, and time loss. For example, a congestion index < 1.5 indicates smooth traffic, 1.5 ≤ congestion index < 2.0 indicates slow traffic, and a congestion index ≥ 2.0 indicates congestion. Different diagnostic items correspond to different second preset conditions. For example, when the diagnostic item is an oxygen sensor, the second preset condition corresponding to the congestion level of the oxygen sensor needs to be smooth traffic. However, when the diagnostic item is a VVT / EGR group, the congestion level of the VVT / EGR group can be any one or more of congestion, slow traffic, and smooth traffic. This is because different diagnostic items require different detection conditions. Oxygen sensors need to cover different emission conditions at different vehicle speeds to ensure diagnostic accuracy, while the VVT / EGR system can complete core diagnostics at low speeds or when stationary. Preferably, when the diagnostic item belongs to the VVT / EGR group, the congestion level of the VVT / EGR group is congestion. By controlling the range-extended electric vehicle to enter the reverse towing mode in the congested scenario, the occurrence of the vehicle unexpectedly exiting the reverse towing mode due to road factors can be further reduced. In addition, in the congested situation, energy consumption can be reduced by triggering short-term diagnostics (5 seconds each time) and adopting a low-power mode.

[0046] In one possible implementation of step 130, different diagnostic items correspond to different vehicle operating parameters. As indicated in the previous implementation, different diagnostic items require different conditions to complete the test. To better verify the effectiveness of the diagnosis and improve the probability of successful diagnosis, this application also provides different diagnostic items corresponding to different vehicle operating parameters. Specifically: if the diagnostic item is an oxygen sensor, the vehicle operating parameters include engine parameters and vehicle speed; if the diagnostic item is a VVT / EGR group, the vehicle operating parameters include engine parameters. Oxygen sensor diagnosis needs to be performed at specific vehicle speeds (e.g., 50km / h, 60km / h, 100km / h) to meet the I UPR (actual diagnostic rate) requirements of the OBD system and ensure the sensor's response capability under dynamic operating conditions. VVT / EGR group diagnosis does not require vehicle speed conditions and can be completed at low speeds or in a stationary state. Engine parameters include at least one of engine speed, engine coolant temperature, aftertreatment exhaust temperature, intake air temperature, and intake air flow. The conditions corresponding to engine parameters include engine parameters exceeding a corresponding threshold, where the threshold can be set according to the characteristics of different vehicles, engines, and aftertreatment systems.

[0047] In one possible implementation of step 130, the reverse towing control device can send an engine fuel cut-off command to the engine control unit (EMS) and simultaneously send a motor speed maintenance command to the generator controller (GCU) of the range extender. The EMS responds to the engine fuel cut-off command to control the engine fuel cut-off of the range extender, and the GCU responds to the motor speed maintenance command to control the generator speed to be maintained at a preset speed, such as 1500 rpm, so that the range extender can be controlled to enter the reverse towing mode.

[0048] It should be noted that the aforementioned control method is mainly for controlling a range-extended electric vehicle entering a reverse towing condition. Correspondingly, this application also provides a control method for a range-extended electric vehicle exiting a reverse towing condition. After the range-extended electric vehicle enters a reverse towing condition, it can promptly exit the reverse towing condition through any of the following implementation methods, reducing the ineffective time the vehicle spends in the reverse towing condition and improving the user experience. Specifically:

[0049] In one possible implementation, after controlling the range extender to enter the reverse towing mode, the method further includes: acquiring vehicle operating parameters corresponding to the diagnostic items in real time; and controlling the range extender to exit the reverse towing mode in response to the vehicle operating parameters not meeting a third preset condition. This implementation reduces the ineffective time the vehicle is in the reverse towing mode by controlling the range extender to exit the reverse towing mode when the vehicle operating parameters do not meet the third preset condition, thereby improving the user experience.

[0050] In another possible implementation, after controlling the range extender to enter the reverse towing mode, the method further includes: calculating the duration of the range extender being in the reverse towing mode; and controlling the range extender to exit the reverse towing mode in response to the duration reaching a preset duration. The duration of the vehicle being in the reverse towing mode can be the duration of continuous fuel cut-off of the engine. This implementation reduces the time wasted in the reverse towing mode due to diagnostic delays by controlling the range extender to exit the reverse towing mode when the duration of the reverse towing mode reaches a preset duration, thus improving the user experience.

[0051] In another possible implementation, after controlling the range extender to enter the reverse towing mode, the method further includes: receiving the current I UPR numerator count value sent by the engine controller in real time, and determining whether the current I UPR numerator count value has increased compared to the historical I UPR numerator count value; the historical I UPR numerator count value is the I UPR numerator count value sent by the engine controller at the moment the range extender enters the reverse towing mode; in response to the current I UPR numerator count value increasing compared to the historical I UPR numerator count value, controlling the range extender to exit the reverse towing mode. An increase in the I UPR numerator count value indicates successful diagnosis after the vehicle enters the reverse towing mode. This implementation reduces unnecessary time spent in the reverse towing mode and improves the user experience by controlling the range extender to exit the reverse towing mode when the current I UPR numerator count value increases compared to the historical I UPR numerator count value.

[0052] like Figure 2 As shown, this application also provides a range-extended electric vehicle (REEV) reversing driving condition control system. This REEV reversing driving condition control system includes a type determination module 210, a target road segment determination module 220, and a reversing driving condition control module 230. The type determination module 210 is configured to, during a driving cycle, determine whether a diagnostic item with an I UPR value less than a corresponding preset limit exists in the on-board diagnostic system, and whether the diagnostic item belongs to the reversing driving condition I UPR increase type. The target road segment determination module 220 is configured to, in response to the diagnostic item belonging to the reversing driving condition I UPR increase type... The UPR enhancement type determines the target road segment from the navigation path planned by the electronic map; wherein, the navigation path is the current movement path of the range-extended electric vehicle, and the target road segment is the road segment ahead of the current position of the range-extended electric vehicle whose road parameters meet the first preset condition; the reverse towing condition control module 230 is configured to control the range extender of the range-extended electric vehicle to enter the reverse towing condition when the range-extended electric vehicle travels to the target road segment, and the congestion level of the target road segment meets the second preset condition corresponding to the diagnostic item and the vehicle condition parameters corresponding to the diagnostic item meet the third preset condition.

[0053] In one embodiment, both the type determination module 210 and the target road segment determination module 220 may include a vehicle control unit (VCU), and the on-board diagnostic system (OBD) runs in the engine control unit (EMS). The reversing condition control module 230 may include the vehicle control unit (VCU), the engine management system (EMS), and the generator control unit (GCU). Next, this application will use this embodiment as an example to illustrate the cooperation between the various devices of the reversing condition control system of a range-extended electric vehicle:

[0054] S1: The system is powered on, and the entire vehicle and engine of the range-extended electric vehicle are running;

[0055] S2: In the type judgment module 210, during a driving cycle, the VCU responds to the presence of a diagnostic item in the on-board diagnostic system (OBD) with an IUPR value less than the corresponding preset limit, and determines whether the diagnostic item belongs to the IUPR increase type of the reverse towing condition.

[0056] S3: In the target road segment determination module 220, the VCU responds to the fact that the diagnostic item belongs to the reverse towing condition I UPR improvement type, and determines the target road segment from the navigation path planned by the electronic map; wherein, the navigation path is the current movement path of the range-extended electric vehicle, and the target road segment is the road segment in front of the current position of the range-extended electric vehicle whose road parameters meet the first preset condition.

[0057] S4: In the reverse towing condition control module 230, the VCU responds to the fact that the range-extended electric vehicle travels to the target road segment, and the congestion level of the target road segment meets the second preset condition corresponding to the diagnostic item and the vehicle condition parameters corresponding to the diagnostic item meet the third preset condition, and sends an engine fuel cut-off command to the EMS, and at the same time sends a motor speed maintenance command to the GCU.

[0058] EMS responds to the engine fuel cut-off command and controls the range extender to cut off the engine fuel. GCU responds to the motor speed maintenance command and controls the generator speed to be maintained at a preset speed, such as 1500 rpm, so that the range extender can be controlled to enter the reverse towing mode.

[0059] In S3, before the VCU sends the engine fuel cut-off command to the EMS and the motor speed maintenance command to the GCU, it can also send a diagnostic request to the OBD in the EMS. After receiving the diagnostic request from the VCU, the OBD parses the diagnostic request from the VCU and responds to the diagnostic request from the VCU to activate the diagnostic process. After the OBD activates the diagnostic process, the VCU sends the engine fuel cut-off command to the EMS and sends the motor speed maintenance command to the GCU at the same time. If the OBD does not activate the diagnostic process, the VCU will not send the engine fuel cut-off command to the EMS and the motor speed maintenance command to the GCU, so as to maintain the normal operation of the vehicle.

[0060] The activation process may include establishing communication between the diagnostic tool and the vehicle system, and triggering sensors and other components to enter the working state to read key data. In addition, the activation process may also include determining whether the engine parameters meet the corresponding conditions. If the corresponding conditions are met, the aforementioned process of establishing communication between the diagnostic tool and the vehicle system and triggering sensors and other components to enter the working state is performed. The engine parameters include at least one of the following: engine speed, engine coolant temperature, after-treatment exhaust temperature, intake air temperature, and intake air flow. The corresponding conditions for the engine parameters include that the engine parameters are greater than the corresponding threshold. The threshold can be set according to the characteristics of different vehicles, different engines, and different after-treatment systems.

[0061] In S3, after the EMS receives the engine fuel cut-off command, before responding to the command and controlling the range extender to cut off the engine fuel, it can also determine whether the engine status parameters meet the corresponding conditions, such as whether the exhaust temperature is too high or the oil temperature is too high. Its main purpose is to protect the engine. In addition, the EMS can also determine whether the actuator status parameters meet the corresponding conditions, such as whether there are faults in the turbocharger, EGR valve, throttle body and mixing valve. Its main purpose is to protect the actuator.

[0062] The engine status parameters may include at least one of the following: exhaust temperature and oil temperature. The conditions corresponding to the engine status parameters include exhaust temperature being less than the corresponding threshold and oil temperature being less than the corresponding threshold. The actuator status parameters include fault codes of the turbocharger, EGR valve, throttle body, and mixing valve. The conditions corresponding to the actuator status parameters include the presence or absence of fault codes of at least one of the turbocharger, EGR valve, throttle body, and mixing valve. Similarly, the aforementioned thresholds may be set according to the characteristics of different vehicles, different engines, and different diesel aftertreatment systems.

[0063] If the EMS determines that the engine status parameters and / or actuator status parameters meet the corresponding conditions, it means that the engine can safely and reliably enter the reverse towing condition. At this time, the engine fuel cut-off command is responded to to control the range extender to cut off the engine fuel. If the conditions are not met, the vehicle will continue to operate normally and the current condition will be maintained.

[0064] In S3, before sending the engine fuel cut-off command to the EMS and the motor speed maintenance command to the GCU, the VCU can also ensure vehicle safety by judging whether the vehicle status parameters meet the corresponding conditions. For example, whether the battery charge (State of Charge, SOC) is higher than the corresponding threshold, whether the battery temperature is lower than the corresponding threshold, and whether the battery and motor are fault-free. If the corresponding conditions are not met, the vehicle will continue to operate normally and will not be controlled for reverse towing. If the corresponding conditions are met, the VCU will send an engine torque reduction request to the EMS to transition from the generator state to the reverse towing state by reducing torque. It will also judge whether the engine torque has dropped to the preset torque. If it has not dropped to the preset torque, the vehicle will continue to operate normally and will not send the engine fuel cut-off command to the EMS or the motor speed maintenance command to the GCU. If it has dropped to the preset torque, the VCU will send the engine fuel cut-off command to the EMS and the motor speed maintenance command to the GCU, so that the vehicle enters the reverse towing state, and the OBD will perform diagnostics.

[0065] The vehicle status parameters include at least one of the following: vehicle operating parameters, battery status parameters, and motor status parameters. The vehicle status parameters reflect whether the vehicle is operating normally and whether the battery and motor are functioning properly. The vehicle operating parameters reflect whether the vehicle is in operation. The battery status parameters reflect whether the battery is currently functioning properly and include battery charge, battery temperature, and battery fault codes. These battery status parameters can be read from the Battery Management System (BMS). The motor status parameters reflect whether the motor is functioning properly and include motor speed, motor temperature, and motor fault codes. These motor status parameters can be read from the Power Electronic Unit (PEU).

[0066] S4: In the reverse towing condition control module 230, the VCU acquires the vehicle condition parameters corresponding to the diagnostic items in real time. In response to the vehicle condition parameters not meeting the third preset condition, the VCU controls the range extender to exit the reverse towing condition; and / or, it counts the duration of the range extender in the reverse towing condition. In response to the duration reaching the preset duration, the VCU controls the range extender to exit the reverse towing condition; and / or, it receives the current I UPR numerator count value sent by the engine controller in real time, and determines whether the current I UPR numerator count value has increased compared to the historical I UPR numerator count value. The historical I UPR numerator count value is the I UPR numerator count value sent by the engine controller when the range extender enters the reverse towing condition. In response to the current I UPR numerator count value increasing compared to the historical I UPR numerator count value, the VCU controls the range extender to exit the reverse towing condition.

[0067] For example, the system monitors whether the duration of the vehicle in a towing condition (e.g., fuel cut-off duration) exceeds a preset duration. If it does, the system sends a request to the EMS to cancel the fuel cut-off and a torque increase request. The EMS responds to the VCU's request to cancel the fuel cut-off and increase torque by supplying fuel and increasing torque until the engine resumes normal power generation and the vehicle continues to operate normally.

[0068] It should be understood that although the foregoing steps and the various steps in the flowchart of this application are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, the foregoing steps and at least some steps in the flowchart of this application may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0069] This application also provides a computer-readable storage medium storing a plurality of instructions adapted for loading by a processor and executing the methods in any of the foregoing embodiments. A processor is provided for executing the plurality of instructions; a memory is provided for storing the plurality of instructions, which are loaded by the processor and executed in the above embodiments for controlling the reversing operation of a range-extended electric vehicle.

[0070] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0071] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A control method for a range-extended electric vehicle in reverse towing mode, characterized in that, include: During a driving cycle, in response to a diagnostic item in the on-board diagnostic system having an I UPR value less than the corresponding preset limit, it is determined whether the diagnostic item belongs to the I UPR enhancement type under towing conditions; the diagnostic item of the I UPR enhancement type under towing conditions is a diagnostic item that needs to be completed under towing conditions. In response to the diagnostic item belonging to the reverse towing condition I UPR enhancement type, the target road segment is determined from the navigation path planned by the electronic map. The navigation path is the current movement path of the range-extended electric vehicle, and the target road segment is the road segment ahead of the current position of the range-extended electric vehicle whose road parameters meet the first preset condition. In response to the extended-range electric vehicle traveling to the target road segment, and the congestion level of the target road segment meeting the second preset condition corresponding to the diagnostic item and the vehicle operating parameters corresponding to the diagnostic item meeting the third preset condition, the range extender of the extended-range electric vehicle is controlled to enter the reverse towing mode; the second preset condition includes the preset congestion level corresponding to the oxygen sensor and the VVT / EGR group.

2. The control method for reverse towing operation of a range-extended electric vehicle as described in claim 1, characterized in that, The road parameters satisfy a first preset condition, including: The slope of the target road segment is less than or equal to a preset slope threshold; The length of the target road segment is greater than or equal to a preset length threshold. The curvature of the target road segment is less than or equal to a preset curvature threshold.

3. The control method for reverse towing operation of a range-extended electric vehicle as described in claim 2, characterized in that, The preset slope threshold is 0%.

4. The control method for reverse towing operation of a range-extended electric vehicle as described in claim 1, characterized in that, After controlling the range extender to enter reverse towing mode, the method further includes: Real-time acquisition of vehicle operating parameters corresponding to the diagnostic items; In response to the vehicle operating parameters not meeting the third preset condition, the range extender is controlled to exit the reverse towing mode.

5. The control method for reverse towing operation of a range-extended electric vehicle as described in claim 1, characterized in that, After controlling the range extender to enter reverse towing mode, the method further includes: The duration of the range extender in reverse towing mode was recorded. In response to the duration reaching a preset duration, the range extender is controlled to exit the reverse towing mode.

6. The control method for reverse towing operation of a range-extended electric vehicle as described in claim 1, characterized in that, After controlling the range extender to enter reverse towing mode, the method further includes: The engine controller receives the current I UPR molecule count value in real time and determines whether the current I UPR molecule count value has increased compared to the historical I UPR molecule count value; the historical I UPR molecule count value is the I UPR molecule count value sent by the engine controller when the range extender enters the reverse towing mode. In response to the current I UPR molecule count value increasing compared to the historical I UPR molecule count value, the range extender is controlled to exit the reverse drag mode.

7. The control method for reverse towing operation of a range-extended electric vehicle as described in claim 1, characterized in that, If the diagnostic item pertains to the oxygen sensor, the vehicle operating parameters include engine parameters and vehicle speed; If the diagnostic item belongs to the VVT / EGR group, the vehicle operating parameters include engine parameters.

8. The control method for reverse towing operation of a range-extended electric vehicle as described in claim 7, characterized in that, The engine parameters include engine speed, engine coolant temperature, aftertreatment exhaust temperature, intake air temperature, and intake air flow rate.

9. A control system for a range-extended electric vehicle in reverse towing mode, characterized in that, include: The type determination module is configured to, during a single driving cycle, in response to a diagnostic item in the on-board diagnostic system having an I UPR value less than a corresponding preset limit, determine whether the diagnostic item belongs to the I UPR increase type under the reverse towing condition. The diagnostic items for the reverse drag condition I UPR enhancement type are diagnostic items that need to be completed under reverse drag conditions; The target road segment determination module is configured to determine the target road segment from the navigation path planned by the electronic map in response to the diagnostic item belonging to the reverse towing condition I UPR improvement type; wherein, the navigation path is the current movement path of the range-extended electric vehicle, and the target road segment is the road segment ahead of the current position of the range-extended electric vehicle whose road parameters meet the first preset condition. The reverse towing control module is configured to control the range extender of the range-extended electric vehicle to enter reverse towing mode in response to the range-extended electric vehicle traveling to the target road segment, and the congestion level of the target road segment meeting the second preset condition corresponding to the diagnostic item and the vehicle operating condition parameters corresponding to the diagnostic item meeting the third preset condition; the second preset condition includes the preset congestion level corresponding to the oxygen sensor and the VVT / EGR group.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a plurality of instructions adapted for loading by a processor and executing the steps of the range-extended electric vehicle reverse towing control method as described in any one of claims 1 to 8.

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