Engine noise reduction and vibration reduction control method of extended-range hybrid vehicle and vehicle

Abstract

This invention discloses an engine noise reduction and vibration control method for a range-extended hybrid electric vehicle (REEV), as well as the vehicle itself. The control method includes: when the vehicle is in an engine idling and generating electricity, classifying the power generation load level according to the real-time electric power demand of the vehicle and causing the engine to output a corresponding target speed; when the vehicle is in motion, classifying the battery's state of charge (SOC) and setting a stepped engine start-up speed threshold to suppress frequent low-speed start-stops; when the vehicle is parked, actively limiting the engine speed under safe battery SOC conditions, and releasing the engine speed limitation through a dual path of vehicle speed and parking time. This method requires no hardware modification and, while ensuring the vehicle's power generation function, battery SOC safety, and parking safety, suppresses noise and vibration excitation at the source, significantly improving the in-vehicle quietness and driving experience during parking and low-speed conditions. It balances power preservation and noise reduction, adapts to complex operating conditions, and has strong compatibility and practicality.

Description

Technical Field

[0001] This invention relates to the technical field of automobile manufacturing, and in particular to a method for engine noise reduction and vibration control in range-extended hybrid electric vehicles, as well as the vehicle itself. Background Technology

[0002] Range-extended hybrid electric vehicles (REEVs) have become a mainstream technology due to the smoothness of pure electric driving and the convenience of refueling. In these vehicles, the engine primarily functions as a range extender for power generation, and the overall driving quality is highly dependent on the engine's operational control strategy. In low-temperature environments, when the vehicle is in a parked power generation state, factors such as decreased combustion stability, increased mechanical damping, and changes in suspension system stiffness can easily generate low-frequency noise and structural vibrations. This leads to a significant deterioration in cabin quietness, severely impacting ride comfort and the user's perceived quality of life.

[0003] Existing range-extended vehicle engine control strategies primarily focus on power generation efficiency and battery charge retention, with insufficient consideration given to noise and vibration optimization under parking and low-speed conditions. This often results in issues such as unreasonable engine speed matching, frequent start-stop cycles in low-speed ranges, and engine speed fluctuations when the vehicle is stopped and generating power. These issues can easily trigger powertrain vibration and in-vehicle noise, significantly reducing ride comfort.

[0004] To address the aforementioned issues, while existing technologies offer some optimization solutions for the NVH performance of range extenders, these are mostly single-dimensional control improvements, such as simply reducing engine idle speed or decreasing start-stop frequency. They lack a systematic control strategy covering all time-series conditions, including parking and low-speed operation, resulting in limited optimization effects. Furthermore, they may sacrifice power generation efficiency or battery charging capacity in an excessive pursuit of noise suppression, making them unsuitable for the complex actual operating conditions of range extender vehicles and failing to meet the demands for improved overall vehicle driving quality. Summary of the Invention

[0005] This invention aims to solve the technical problems existing in the above-mentioned related technologies and proposes an engine noise reduction and vibration control method for range-extended hybrid electric vehicles. Under the premise of ensuring the energy supply requirements of the whole vehicle and the safety boundary of battery SOC, the optimal engine speed strategy is dynamically planned and executed, thereby suppressing noise and vibration excitation at the source.

[0006] A method for engine noise reduction and vibration damping control of a range-extended hybrid electric vehicle according to a first aspect embodiment of the present invention includes: When the car is in the engine idling power generation state, the power generation load level is divided according to the real-time electric power demand of the vehicle, and the engine output is controlled to match the target speed of the power generation load level, so that the engine speed reaches a low level while meeting the power generation function requirements. When the car is in motion, the power battery is divided into charge levels according to the SOC of the power battery, and the minimum vehicle speed threshold required to start the engine is set for different charge levels. Under the premise of ensuring the bottom line of the power protection function, the frequent start-stop of the engine under low-speed conditions is suppressed. When the car is parked, the engine speed is actively limited when the power battery SOC meets the preset safety conditions, and the active limitation on engine speed is lifted after the car speed continuously reaches the preset driving threshold or the parking time exceeds the preset time.

[0007] The engine noise reduction and vibration control method for range-extended hybrid electric vehicles according to embodiments of the present invention has at least the following beneficial effects: Addressing the significant noise problem caused by low-temperature conditions, this method uses engine speed as the core of regulation and achieves coordinated optimization of engine operating status through three measures: power graded control, low-speed start-up limitation, and parking speed control. This effectively suppresses noise and vibration caused by engine operation in low-temperature environments while ensuring basic power generation functions and parking safety. It suppresses noise and vibration excitation caused by engine operation at the source, significantly improving in-vehicle quietness and overall driving experience under parking and low-speed conditions. Furthermore, it comprehensively considers the vehicle's energy supply needs and the power battery's SOC safety boundary, avoiding problems such as reduced power generation efficiency and insufficient power reserve capacity caused by single-dimensional optimization. It is adaptable to the complex actual operating conditions of range-extended hybrid electric vehicles. Moreover, this control method does not require modification of the vehicle's hardware structure, is simple to implement, and has strong compatibility. It can be widely applied to various range-extended hybrid electric vehicles, improving driving quality without affecting the vehicle's original core functions of power generation and power reserve.

[0008] According to some embodiments of the present invention, the step of classifying the power generation load level according to the real-time electric power demand of the vehicle includes: When the real-time electric power demand of the whole vehicle is consistently less than 5kW, it is judged as a low power generation load level; When the real-time electric power demand of the vehicle is consistently greater than 7kW, it is judged as a high power generation load level.

[0009] According to some embodiments of the present invention, controlling the engine output to match the target rotational speed of the power generation load level includes: When the low power generation load level is reached, the target speed of the engine is K, which is in the amplitude valley region of the engine's first-order combustion excitation frequency and is higher than the lower limit of stable combustion in cold engine. When the high power generation load level is reached, the target speed of the engine is a value P, which is within the engine power generation efficiency plateau region and avoids the engine's second-order torsional vibration sensitive region.

[0010] According to some embodiments of the present invention, when the low power generation load level is reached, the K value is 850 rpm; when the high power generation load level is reached, the P value is 1350 rpm.

[0011] According to some embodiments of the present invention, the step of classifying the power battery capacity levels based on the SOC of the power battery includes: When the SOC of the power battery is less than A%, it is judged to be in a low capacity level. When A%≤Power Battery SOC≤B%, it is judged as medium capacity level; When the SOC of the power battery is greater than B%, it is judged to be of a high capacity level.

[0012] According to some embodiments of the present invention, setting the minimum vehicle speed threshold required for engine starting under different battery levels includes: When the low battery level is reached, the minimum vehicle speed threshold required to start the engine is >0. When the aforementioned medium-electricity level is reached, the minimum vehicle speed threshold required to start the engine is >10km / h; When the high battery level is reached, the minimum vehicle speed threshold required to start the engine is >30km / h.

[0013] According to some embodiments of the present invention, the step of actively limiting the engine speed when the power battery SOC meets preset safety conditions includes: When the SOC of the power battery is greater than or equal to 20%, the engine speed is actively limited to a value of K. The value of K is in the amplitude valley region of the first-order combustion excitation frequency of the engine and is higher than the lower limit of stable combustion in cold engine.

[0014] According to some embodiments of the present invention, the step of releasing the active limitation on engine speed after the vehicle speed has continuously reached a preset driving threshold or the vehicle has been stopped for more than a preset time includes: When the vehicle speed is continuously greater than 3 km / h or the vehicle remains stationary for more than 3 minutes, the active limitation on engine speed is lifted.

[0015] According to a second aspect of the present invention, an automobile includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the above-described engine noise reduction and vibration damping control method for a range-extended hybrid electric vehicle.

[0016] A computer program product according to a third aspect of the present invention includes a computer program stored on a computer-readable storage medium, which, when executed by a processor, implements the above-described engine noise reduction and vibration damping control method for a range-extended hybrid electric vehicle.

[0017] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] Figure 1 This is a control schematic diagram of the engine noise reduction and vibration damping control method provided in the embodiment of the present invention. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0020] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0021] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0022] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0023] like Figure 1As shown, this invention provides an engine noise reduction and vibration control method for a range-extended hybrid electric vehicle. This method is applied to the vehicle control unit (VCU) of the range-extended hybrid electric vehicle and is designed around three core operating conditions: engine idling power generation, vehicle driving, and vehicle parking. Through three coordinated control measures, the method achieves fine-grained regulation of the engine's operating state. The three measures are independent of each other and can be uniformly scheduled and prioritized by the vehicle control unit. Under the premise of ensuring the vehicle's power generation function requirements, the power battery SOC safety boundary, and parking safety, the method suppresses the noise and vibration excitation generated during engine operation from the source, effectively improving the quietness of the vehicle interior under operating conditions such as parking and low-speed crawling, and significantly improving the overall driving experience. In particular, it has a significant optimization effect on the problem of decreased engine combustion stability and increased noise and vibration caused by the coupling of low temperature and parking conditions. This control method does not require any modification to the vehicle's original hardware structure. It can be implemented simply through software strategy optimization of the vehicle controller. It is easy to implement, highly compatible, and can be widely adapted to the actual operating conditions of various range-extended hybrid electric vehicles. At the same time, it takes into account the energy supply of the whole vehicle and the battery power supply requirements throughout the process, avoiding problems such as reduced power generation efficiency and insufficient power supply capacity caused by single-dimensional NVH optimization. While improving driving quality, it does not affect the normal realization of the vehicle's original core functions of power generation and power supply.

[0024] In this invention, when the vehicle is in an engine idling and generating electricity state, a power grading control strategy is implemented. This strategy takes noise experience as the core design principle and power generation capacity as a backup. When the vehicle is in an idling and generating electricity state, the power generation load level is dynamically divided according to the coupling condition between the real-time electric power demand of the vehicle and the real-time vehicle speed. The engine output is controlled to match the target speed of the power generation load level, so as to achieve a low level of engine speed while meeting the power generation function requirements. In this way, while ensuring the supply of electric power to the whole vehicle, the noise and vibration generated by the engine operation are minimized.

[0025] Specifically, the determination of the power generation load level is primarily based on the real-time electric power demand of the vehicle, supplemented by vehicle speed. Both conditions must be met simultaneously, and both must be maintained for a preset duration. This avoids misjudgment of the load level due to instantaneous fluctuations in vehicle speed or electric power demand, which could lead to frequent engine speed changes and increased noise and vibration. In this embodiment, the preset duration for determination is 300ms. This duration can be adaptively adjusted according to the tuning requirements of different vehicle models and is not a fixed value.

[0026] When the vehicle speed is consistently ≤1km / h and the real-time electric power demand of the vehicle is consistently <5kW, it is judged as a low power generation load level. At this time, the vehicle's electric power demand is low. Scenarios such as the vehicle crawling at low speed without high-power electrical equipment being turned on, or the vehicle being parked with some electrical equipment turned on, will trigger the low power generation load level judgment. When the vehicle speed is consistently >3km / h and the real-time electric power demand of the vehicle is consistently >7kW, it is judged as a high power generation load level. This level often occurs when the vehicle is idling and crawling with high-power electrical equipment such as air conditioning and heating being turned on, or when there is a large power replenishment demand during the vehicle's crawling process. For the intermediate range of real-time electric power demand of the whole vehicle between 5kW and 7kW, this invention classifies it as an extended range of low power generation load level. At this time, the engine still outputs the target speed that matches the low power generation load level, so as to ensure the stability of the speed and avoid frequent speed adjustment caused by too fine division of the range. At the same time, the speed control strategy of this intermediate range can also be adaptively optimized according to the NVH tuning requirements of different models. It can be slightly adjusted based on the target speed of the low power generation load level, as long as the dual requirements of noise and vibration suppression and power generation function are met.

[0027] After determining the power generation load level, the engine will output a target speed matching the corresponding level. When the low power generation load level is reached, the engine's target speed is set to a value K. The value K must simultaneously meet two core conditions: it must be within the amplitude trough region of the engine's first-order combustion excitation frequency and higher than the engine's cold-start stable combustion lower limit. The amplitude trough region of the engine's first-order combustion excitation frequency is the speed range where the vibration intensity and energy generated by the engine's combustion excitation are the smallest. Operating within this range can significantly suppress low-frequency vibration and noise of the engine. The cold-start stable combustion lower limit is the minimum speed at which the engine can achieve stable combustion in a cold-start state. Exceeding this speed can effectively prevent noise degradation caused by engine stalling, misfire, and vibration, and is especially suitable for engine operation control under low-temperature conditions.

[0028] When reaching high power generation load levels, the target engine speed is set to the P value. The P value must be within the engine's power generation efficiency plateau range and avoid the engine's second-order torsional vibration sensitive zone. The engine's power generation efficiency plateau range is the speed range where the fuel consumption rate is lowest and the electrical energy conversion efficiency is highest when the engine drives the generator to generate electricity. Operating within this range can meet the high power demand of the entire vehicle while ensuring power generation efficiency and avoiding fuel waste. The second-order torsional vibration sensitive zone is the sensitive speed range where the engine powertrain generates second-order torsional vibration. Avoiding this range can effectively suppress the mid-to-high frequency whine and vibration of the powertrain, ensuring a good driving experience.

[0029] In this embodiment, the K value corresponding to the low power generation load level is 850 rpm, and the P value corresponding to the high power generation load level is 1350 rpm. These values ​​are the preferred values ​​selected by the present invention based on the operating conditions and NVH optimization requirements of range-extended hybrid electric vehicles, effectively balancing noise suppression, combustion stability, and power generation efficiency. However, it should be noted that the specific values ​​of K and P can be adjusted adaptively for different vehicle models due to differences in engine type, powertrain matching, and overall vehicle NVH tuning requirements. They are not uniquely limited, as long as the corresponding speed range conditions mentioned above are met.

[0030] For example, if the SOC of the car's power battery is 20%, the air conditioning is not turned on, and the car is stationary, the low SOC of the power battery meets the conditions for starting the range extender, and the engine starts. At this time, the conditions for the low-speed mode of the power graded control engine speed strategy are met, and the engine speed is maintained at 850 rpm. After the air conditioning is turned on, the conditions for the high-speed mode of the power graded control engine speed strategy are met, and the engine speed increases to 1350 rpm.

[0031] Furthermore, when the vehicle is in motion, this invention implements a low-speed start-up restriction strategy. This strategy uses the power battery SOC as the main decision variable, divides the power battery SOC into multiple charge levels, and sets a minimum vehicle speed threshold for engine start-up for different charge levels. By gradually increasing the engine start-up speed threshold, the noise problem caused by frequent engine start-stop under low-speed conditions is suppressed while ensuring the bottom line of battery charge protection. This achieves a dynamic balance between battery charge protection and driving quietness.

[0032] Specifically, the State of Charge (SOC) of the power battery is divided into three levels: low, medium, and high. When the SOC is less than A%, it is considered to be in the low-charge level. In this embodiment, A is set to 25, which is the low-charge warning threshold for the power battery. When the SOC is below this value, the vehicle's power supply requirement is rigidly constrained. At this time, there is no speed threshold for engine starting; the engine can be triggered as long as the vehicle speed is greater than 0. This ensures that the engine can generate electricity to replenish the battery in a timely manner, preventing the power battery from affecting the normal operation of the vehicle due to low charge. It also prevents performance degradation of the power battery due to low charge under low-temperature conditions.

[0033] When A% ≤ SOC ≤ B%, it is considered to be at a medium charge level. In this embodiment, the value of B is chosen as 50, which is the threshold between medium and high charge levels for the power battery. When the SOC of the power battery is in this range, the battery charge can support the vehicle's basic pure electric operation, balancing power supply needs with noise optimization requirements. At this time, the minimum vehicle speed threshold for engine start permission is >10km / h, thereby avoiding frequent engine start-stops in the low-speed creep range of 0-10km / h. The 0-10km / h range is a common operating condition for urban road driving and is also the range where drivers and passengers are most sensitive to noise and vibration. By increasing the starting speed threshold, the number of engine start-stops in this range can be effectively reduced, improving the driving experience.

[0034] When the SOC of the power battery is greater than B%, it is judged as a high-capacity level. At this time, the power battery is fully charged, and the vehicle can run entirely on pure electric power. Noise experience optimization becomes the main goal. Therefore, the minimum speed threshold for engine start permission is raised to >30km / h to completely eliminate engine start-stop in urban low-speed congestion scenarios, allowing passengers to enjoy the quietness and smoothness of pure electric driving during low-speed driving.

[0035] It should be clarified that the values ​​A and B in this embodiment are preferred values ​​that conform to the usage characteristics and operating conditions of the power battery of the range-extended hybrid electric vehicle. Different OEMs can adaptively adjust the values ​​A and B according to their own power battery selection, vehicle power preservation strategy, and NVH tuning requirements, and they are not the only limitations. At the same time, the minimum engine start speed threshold corresponding to each battery level can also be fine-tuned according to the usage scenarios and user needs of different models. For example, some models mainly for urban commuting can appropriately increase the start speed threshold for high battery levels, while some models mainly for long-distance driving can appropriately lower the start speed threshold for medium battery levels, with the core goal of achieving stepped suppression of low-speed start-stop noise.

[0036] For example, if the battery's SOC is 60%, the air conditioning is on, and the vehicle speed is 25 km / h, the high battery SOC meets the high-charge-level condition for low-speed engine start-up, and the engine does not start. As the vehicle continues to travel, when the battery SOC is depleted to 35%, the medium-charge-level condition for low-speed engine start-up is triggered, and the engine starts generating electricity. Once the vehicle speed drops to 10 km / h, the engine stops. As the vehicle continues to travel, when the battery SOC is depleted to below 25%, the low-charge-level condition for low-speed engine start-up is triggered, and the engine starts generating electricity.

[0037] Finally, when the car is parked, the present invention implements a parking speed limiting strategy. This strategy is enabled when the power battery SOC meets the preset safety conditions. By actively limiting the engine's idling speed, it suppresses noise degradation caused by low-speed vibration under stationary conditions. At the same time, it designs a dual-path speed limiting release mechanism to take into account both the quietness requirements of short-term parking and the power preservation requirements of long-term parking. It is especially suitable for low-temperature parking and power generation scenarios, and can effectively solve the problems of unstable engine combustion and increased vibration noise in such scenarios.

[0038] Specifically, this strategy uses a power battery SOC ≥ 20% as a preset safety condition. This threshold is the basic charge protection threshold for the power battery. When the SOC is higher than this threshold, the power battery has a certain charge buffer space, prioritizing quiet operation. When the power battery SOC < 20%, the engine will operate according to the normal idling strategy, prioritizing power generation and preventing the power battery from becoming too low. When the power battery SOC ≥ 20%, the trigger condition for speed limiting is a vehicle speed continuously < 1 km / h. At this time, the vehicle controller determines that the vehicle is in a parked state and actively limits the engine speed to a K value through output commands. This K value is the same as the K value for the low power generation load level in the power graded control strategy, that is, it is in the amplitude trough region of the engine's first-order combustion excitation frequency and higher than the lower limit of stable combustion when the engine is cold. This speed can effectively suppress low-speed vibration and low-frequency noise of the engine when parked, improving the quietness of the vehicle interior when parked. At the same time, the K value can also be adaptively adjusted according to the tuning requirements of different models and is not a unique limitation.

[0039] Simultaneously with triggering the engine speed limit, the vehicle controller will start a 3-minute timer and enter the dual-path release determination phase of the speed limit. The first release path is speed-triggered. When the vehicle speed increases and remains above 3 km / h, the vehicle controller determines that the vehicle will re-enter the driving state and immediately releases the active limitation on the engine speed, and the engine speed control returns to the normal control strategy. The second release path is time-triggered. When the vehicle's parking state is maintained for a cumulative total of 3 minutes, the vehicle controller determines that the vehicle is not in a short-term parking scenario such as waiting at a traffic light or temporarily pulling over, but rather has a long-term parking need. At this time, the active limitation on the engine speed will be released, and the engine speed control will return to the power graded control strategy, thereby ensuring that the engine can adjust its speed according to the vehicle's electric power demand, achieving efficient power generation and replenishment, while also taking into account the power preservation needs of long-term parking.

[0040] After the engine speed limit is lifted, if the vehicle again meets the parking condition of continuously <1km / h, the timer of the vehicle controller is forcibly reset and the engine speed limit is retried, thus realizing the cyclical control of the engine speed limit in the parking state. This dual-path release mechanism design allows for differentiated control between short-term parking and long-term parking. After deceleration and stopping, priority is given to ensuring quietness, allowing passengers to enjoy a good level of tranquility during short-term parking. However, when the parking time exceeds 3 minutes, it automatically switches to battery protection priority to meet the power generation and charging needs of the vehicle during long-term parking, effectively balancing the NVH experience and battery power protection requirements under parking conditions. It is understandable that the aforementioned 3-minute timing threshold can be adaptively adjusted according to the tuning requirements of different OEMs and is not a unique limitation.

[0041] For example, if the SOC of the car's power battery is 25%, the air conditioning is on, and the car stops while driving, the low SOC of the power battery meets the conditions for starting the range extender, and the engine starts, meeting the parking speed limit. At this time, the engine speed is limited to 850 rpm. After a cumulative parking time of more than 3 minutes, such as driving at a very low speed and parking for more than 3 minutes or continuously parking for more than 3 minutes, the engine speed limit is lifted. Since the power graded control engine speed strategy is met at this time, the engine speed increases to 1350 rpm.

[0042] The three control measures of this invention are respectively adapted to the steady-state, transition, and parking phases of range-extended hybrid electric vehicles during low-speed operation. The control objectives are mutually exclusive, the triggering conditions are independent, and the objects of action are clearly defined. Together, they constitute a systematic and hierarchical control scheme aimed at improving the low-speed noise experience. Through unified scheduling by the vehicle controller, seamless integration and synergistic optimization of the three measures can be achieved. During actual vehicle operation, the vehicle controller will collect core parameters such as vehicle speed, real-time electric power demand, and battery SOC in real time. Based on parameter changes, it will determine the vehicle's operating condition and automatically switch and execute the corresponding control strategy. When the vehicle transitions from a driving state to a low-speed creeping idling power generation state, it seamlessly switches from a low-speed start-up limiting strategy to a power tiered control strategy, adjusting the engine speed according to vehicle speed and power demand. When the vehicle transitions from a driving state to a parked state, it switches from a low-speed start-up limiting strategy to a parking speed limiting strategy, limiting the engine speed while meeting the State of Charge (SOC) condition. When the vehicle transitions from a parked state back to a driving state, the parking speed limiting strategy is lifted, and the vehicle switches to the corresponding control strategy based on vehicle speed and SOC status. The entire process requires no manual intervention, achieving fully automatic and precise control of the engine's operating status.

[0043] The control method of this invention achieves comprehensive suppression of noise and vibration in range-extended hybrid electric vehicles (REEVs) under low-speed and parking conditions through the synergistic optimization of three measures: power graded control, low-speed start-up limitation, and parking speed control. This addresses the two core dimensions of engine speed regulation and start-stop timing control. Simultaneously, it considers both the vehicle's power generation function and the battery's power supply requirements throughout the process. This solves the technical problems of existing range-extended vehicle engine control strategies that prioritize efficiency over NVH, or sacrifice power generation and power supply capabilities for single-dimensional NVH optimization. This method is particularly suitable for low-temperature parking conditions, effectively solving the problems of low-frequency noise and structural vibration caused by decreased engine combustion stability, increased mechanical damping, and changes in suspension system stiffness under these conditions. It suppresses noise and vibration excitation at the source, significantly improving the overall vehicle experience in low-temperature parking scenarios. Furthermore, this method is simple to implement, highly adaptable, and can be widely applied to various types of REEVs, demonstrating significant practical and promotional value.

[0044] This invention also provides a vehicle, which is a range-extended hybrid electric vehicle, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the above-mentioned engine noise reduction and vibration damping control method for range-extended hybrid electric vehicles. By using the software program of this control method on the vehicle controller, precise control of engine speed and start-stop can be achieved without the need for additional hardware equipment, resulting in low implementation cost and strong compatibility.

[0045] It is understood that the automobile protected by this invention can be a private car, such as a sedan, SUV, MPV, or pickup truck. The automobile can also be a commercial vehicle, such as a van, bus, small truck, or large trailer.

[0046] This invention also provides a computer program product, including a computer program or computer instructions, stored in a computer-readable storage medium. A processor of a computer device reads the computer program or computer instructions from the computer-readable storage medium and executes the computer program or computer instructions, causing the computer device to perform the aforementioned engine noise reduction and vibration damping control method for a range-extended hybrid electric vehicle. This computer program product can be integrated into the vehicle controller of existing range-extended hybrid electric vehicles through software upgrades, achieving NVH performance optimization for existing models and possessing broad application prospects.

[0047] It is worth noting that, since the computer program product of this embodiment can execute the engine noise reduction and vibration damping control method of any of the above embodiments of the range-extended hybrid electric vehicle, the specific implementation method and technical effects of the computer program product of this embodiment can be referred to the specific implementation method and technical effects of the engine noise reduction and vibration damping control method of any of the above embodiments of the range-extended hybrid electric vehicle.

[0048] It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically include computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0049] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0050] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for engine noise reduction and vibration damping control in a range-extended hybrid electric vehicle, characterized in that, include: When the car is in the engine idling power generation state, the power generation load level is divided according to the real-time electric power demand of the vehicle, and the engine output is controlled to match the target speed of the power generation load level, so that the engine speed reaches a low level while meeting the power generation function requirements. When the car is in motion, the power battery is divided into charge levels according to the SOC of the power battery, and the minimum vehicle speed threshold required to start the engine is set for different charge levels. Under the premise of ensuring the bottom line of the power protection function, the frequent start-stop of the engine under low-speed conditions is suppressed. When the car is parked, the engine speed is actively limited when the power battery SOC meets the preset safety conditions, and the active limitation on engine speed is lifted after the car speed continuously reaches the preset driving threshold or the parking time exceeds the preset time.

2. The engine noise reduction and vibration damping control method for a range-extended hybrid electric vehicle according to claim 1, characterized in that, The classification of power generation load levels based on the real-time electric power demand of the vehicle includes: When the real-time electric power demand of the whole vehicle is consistently less than 5kW, it is judged as a low power generation load level; When the real-time electric power demand of the vehicle is consistently greater than 7kW, it is judged as a high power generation load level.

3. The engine noise reduction and vibration damping control method for a range-extended hybrid electric vehicle according to claim 2, characterized in that, The control of the engine output to match the target speed of the power generation load level includes: When the low power generation load level is reached, the target speed of the engine is K, which is in the amplitude valley region of the engine's first-order combustion excitation frequency and is higher than the lower limit of stable combustion in cold engine. When the high power generation load level is reached, the target speed of the engine is a value P, which is within the engine power generation efficiency plateau region and avoids the engine's second-order torsional vibration sensitive region.

4. The engine noise reduction and vibration damping control method for a range-extended hybrid electric vehicle according to claim 3, characterized in that: When the low power generation load level is reached, the K value is 850 rpm; When the high power generation load level is reached, the P value is 1350 rpm.

5. The engine noise reduction and vibration damping control method for a range-extended hybrid electric vehicle according to claim 1, characterized in that, The method of classifying power capacity levels based on the state of charge (SOC) of the power battery includes: When the SOC of the power battery is less than A%, it is judged to be in a low capacity level. When A%≤Power Battery SOC≤B%, it is judged as medium capacity level; When the SOC of the power battery is greater than B%, it is judged to be of a high capacity level.

6. The engine noise reduction and vibration damping control method for a range-extended hybrid electric vehicle according to claim 5, characterized in that, The setting of minimum vehicle speed thresholds required to start the engine under different battery levels includes: When the low battery level is reached, the minimum vehicle speed threshold required to start the engine is >0. When the aforementioned medium-electricity level is reached, the minimum vehicle speed threshold required to start the engine is >10km / h; When the high battery level is reached, the minimum vehicle speed threshold required to start the engine is >30km / h.

7. The engine noise reduction and vibration damping control method for a range-extended hybrid electric vehicle according to claim 1, characterized in that, The active limitation of engine speed when the power battery SOC meets preset safety conditions includes: When the SOC of the power battery is greater than or equal to 20%, the engine speed is actively limited to a value of K. The value of K is in the amplitude valley region of the first-order combustion excitation frequency of the engine and is higher than the lower limit of stable combustion in cold engine.

8. The engine noise reduction and vibration damping control method for a range-extended hybrid electric vehicle according to claim 7, characterized in that, The active limitation on engine speed is lifted after the vehicle speed continuously reaches a preset driving threshold or the vehicle has been stopped for more than a preset time, including: When the vehicle speed is continuously greater than 3 km / h or the vehicle remains stationary for more than 3 minutes, the active limitation on engine speed is lifted.

9. A vehicle comprising a memory and a processor, characterized in that, The memory stores a computer program, and when the processor executes the computer program, it implements the engine noise reduction and vibration control method for a range-extended hybrid electric vehicle as described in any one of claims 1 to 8.

10. A computer program product comprising a computer program stored on a computer-readable storage medium, characterized in that, When the computer program is executed by the processor, it implements the engine noise reduction and vibration damping control method for the range-extended hybrid electric vehicle as described in any one of claims 1 to 8.

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