A control system and method for a quiet mode of a range-extended vehicle when driving at low speed
By introducing a quiet mode control system into range-extended vehicles, and using driving condition judgment and energy management modules to control engine speed and torque, the noise problem at low speeds is solved, improving the driving experience and NVH quality.
Patent Information
- Application Number
- CN202410751688.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-12
- Publication Date
- 2026-05-15
- Estimated Expiration
- 2044-06-12
AI Technical Summary
When a range-extended vehicle is driving at low speeds, the engine frequently enters high-speed, high-torque conditions, resulting in loud noise and affecting the driving experience.
The driving condition judgment module determines low-speed driving conditions and prompts the driver to enter silent mode. The energy management module controls the engine to run at a lower speed and torque. Combined with pure electric mode and engine power generation, the quietness requirement is prioritized, sacrificing some fuel consumption.
It reduces engine noise at low speeds, improves the NVH quality of the cab, enhances the driving experience, and automatically exits the silent mode according to the driver's needs.
Smart Images
Figure CN119142317B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of automotive technology, specifically a control system and method for a silent mode when a range-extended vehicle is driving at low speed. Background Technology
[0002] Current energy management strategies for range-extended electric vehicles (REEVs) control engine startup based on driver needs and vehicle energy information. The engine operates within its optimal fuel consumption range, engaging in either propulsion or power generation to meet driving requirements. However, at low speeds, frequent starts and stops, and lane changes for overtaking, the engine frequently enters high-speed, high-torque operation. Higher engine speeds generate significant noise, negatively impacting the driving experience. Therefore, designing a quiet mode that adjusts engine operation to minimize noise and improve driving comfort is essential. Summary of the Invention
[0003] To address the aforementioned technical problems, this invention provides a control system and method for a quiet mode in low-speed driving of a range-extended vehicle. This system can control the engine to run at a lower speed during low-speed driving, thereby improving the NVH quality of the cab and enhancing the driving experience.
[0004] The technical solution of this invention is described below in conjunction with the accompanying drawings:
[0005] In a first aspect, the present invention provides a control system for a silent mode when a range-extended vehicle is in operation, comprising:
[0006] The prompt module is used to prompt the driver;
[0007] The mode selection module is used to select the mode;
[0008] The driving condition judgment module is used to determine whether the driving conditions are suitable for low-speed driving. If the conditions are met, a prompt signal is sent to the prompt module to indicate whether to enter silent mode.
[0009] The function selection module is used to control whether to enter silent mode;
[0010] The energy management module receives instructions from the mode selection module and executes the control to enter or exit silent mode.
[0011] The engine management module receives the target speed and target torque commands calculated by the energy management module, comprehensively judges the engine operating status, and executes speed control and torque control.
[0012] The driving condition judgment module is connected to the prompt module and the energy management module; the energy management module is connected to the mode selection module and the engine management module.
[0013] Furthermore, the driving condition judgment module receives vehicle speed signals and accelerator pedal signal information, and determines whether it meets the low-speed driving conditions based on the parking time and frequency information.
[0014] Furthermore, the function selection module supports both turning the prompt function on and off. When turned off, it will no longer enter the driving condition judgment and will not issue a prompt message asking whether to enter silent mode. The function switch can be turned on when needed.
[0015] Secondly, the present invention also provides a method for controlling the quiet mode of a range-extended vehicle during operation, comprising:
[0016] The driving condition judgment module determines whether the driving condition meets the requirements based on the received vehicle speed signal, accelerator pedal signal, and parking time and frequency information.
[0017] If the system determines that the driving conditions are suitable for low-speed driving, it sends a prompt signal to the prompt module asking whether to enter silent mode, and the prompt module then prompts the driver.
[0018] The driver control mode selection module enters silent mode;
[0019] The energy management module receives instructions from the mode selection module, executes the control to enter silent mode, and calculates the target speed and target torque;
[0020] The engine management module receives the target speed and target torque commands calculated by the energy management module, comprehensively judges the engine operating status, and executes speed control and torque control.
[0021] Furthermore, the specific method for determining whether a low-speed driving condition is met is as follows:
[0022] Set the vehicle speed V0 to be judged. If the vehicle does not exceed V0 within the time T0 period, and the number of times the vehicle speed is 0 during this period exceeds N0; define the small throttle travel P0. If the throttle travel exceeds P0 or the number of times the throttle travel exceeds P1 within the time T0 period is N1, it is judged to be in a low-speed driving condition.
[0023] Furthermore, the energy management module's silent mode control is divided into two parts, as detailed below:
[0024] The first part considers maximizing the use of pure electric mode; when the power battery SOC is lower than a certain value... L When the battery is in silent mode, it will exit pure electric mode and enter range-extended mode, starting the engine to participate in power generation; the design reduces the SOC of the power battery that triggers range-extended mode in silent mode. L The value is based on the current power consumption P of the high-voltage accessories. H The power consumption P of the high-voltage accessory is designed. H Equal to the power P of DC-DC DCDCPTC power P PTC The power P of the compressor AC The sum of, i.e., P H =P DCDC +P PTC +P AC Set Δ soc Calculate the target SOC for exiting pure electric mode. T SOC T =SOC L -Δ soc This is used to control and reduce the SOC value when exiting pure electric mode, ensuring that the vehicle remains in pure electric mode for a longer period of time; such as the power consumption P of high-voltage accessories. H If the elevation reaches the limit, it will revert to the original SOC. L Values should be prioritized to meet energy management needs.
[0025] The second part, based on the vehicle's power requirements, determines the additional power Px that the engine needs to supplement beyond the available power provided by the battery. This is calculated using the universal formula for torque-power ratio, T = 9550P / n. Based on the engine's universal characteristics, the optimal fuel consumption speed at a given power output is determined by subtracting the set speed offset value Δ. n The set RPM corresponds to a specific torque value, aiming to reduce RPM while meeting power requirements and achieving a quieter operation. The torque point at this RPM satisfies power needs but falls outside the optimal fuel consumption range, sacrificing some fuel economy. Considering that higher vehicle speeds result in greater external noise under normal driving conditions, reducing RPM for quieter operation is less effective at higher speeds; therefore, a lower RPM value Δ is set. n The torque is relatively low, which reduces the upper limit of high fuel consumption; at lower vehicle speeds, the corresponding engine speed is also relatively low. n To achieve better noise reduction, the engine's torque and speed are adjusted based on its universal characteristics at a fixed power output. Lower speeds can meet torque requirements, but fuel consumption is not optimal. Therefore, the engine is controlled at the lowest speed that meets torque requirements, based on power needs. Automatic exit conditions are designed: when the vehicle speed exceeds the judged speed V0 for a duration greater than T1; or the accelerator pedal travel exceeds P1; or the accelerator pedal travel exceeds P2 more than N2 times; or the accelerator pedal travel exceeds P3 more than N3 times, based on the principle of prioritizing driver needs, the engine automatically exits the quiet mode and sends an exit notification to the notification module. After exiting, the system enters an automatic recovery condition check. If the low-speed driving conditions defined by the driving condition judgment module are met, the engine automatically re-enters quiet mode and notifies the driver that it has entered quiet mode. This automatic recovery condition check will not re-enter until the current driving cycle ends or the quiet mode is manually closed.
[0026] The beneficial effects of this invention are as follows:
[0027] 1) This invention controls the engine to run at a lower speed when driving at low speeds, thereby improving the NVH quality of the cab and enhancing the driving experience;
[0028] 2) Based on the universal characteristics of the engine, this invention responds to torque demand at a lower speed under a fixed power, sacrificing some fuel consumption performance, improving the overall vehicle noise control level, and meeting the special needs of the driver.
[0029] 3) This invention can automatically exit the mode and provide a prompt according to the driver's driving needs. Attached Figure Description
[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.
[0031] Figure 1 This is a schematic diagram of the control system for a range-extended vehicle in a quiet mode during low-speed driving, as described in this invention. Detailed Implementation
[0032] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.
[0033] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0034] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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 limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.
[0035] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0036] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
[0037] Example 1
[0038] See Figure 1 This embodiment provides a control system for a silent mode in a range-extended vehicle, including a prompting module, a mode selection module, a driving condition judgment module, a function selection module, an energy management module, and an engine management module. The driving condition judgment module is connected to the prompting module and the energy management module; the energy management module is connected to the mode selection module and the engine management module.
[0039] The prompt module is used to provide prompts to the driver.
[0040] The mode selection module is used to select the mode.
[0041] The driving condition judgment module receives vehicle speed and accelerator pedal signals. Based on information such as stopping time and frequency, it determines whether the driving condition meets the requirements for low-speed driving. If the condition is met, it sends a prompt signal to the display module indicating whether to enter silent mode to alert the driver. The module can be configured to judge vehicle speed V0; if the vehicle does not exceed V0 within time T0, and the number of times the vehicle speed is 0 exceeds N0, a low-speed driving condition can be determined. It can also define a small accelerator pedal travel P0; if the accelerator pedal travel exceeds P0 within time T0, or the number of times the accelerator pedal travel exceeds P1 N1 does not exceed a certain number (the conditions can be finely designed).
[0042] The function selection module is used to control entering silent mode; it also supports turning the prompt function on and off. When turned off, it will no longer enter the driving condition judgment and will not issue a prompt message asking whether to enter silent mode. The function switch can be turned on again when needed.
[0043] The energy management module receives instructions from the mode selection module and executes the control to enter or exit silent mode. The control scheme consists of two parts. First, it considers maximizing the use of pure electric mode. In general energy mode management, when the power battery SOC falls below a certain value... L When the battery is in silent mode, it will exit pure electric mode and enter range-extended mode, starting the engine to participate in power generation. The design reduces the state of charge (SOC) of the power battery that triggers range-extended mode in silent mode. L The value is based on the current power consumption P of the high-voltage accessories. H The power consumption P of the high-voltage accessory is designed. H Equal to the power P of DC-DC DCDC PTC power P PTC The power P of the compressor AC The sum of, i.e., P H =P DCDC +P PTC +P AC Set Δ soc Calculate the target SOC for exiting pure electric mode. T SOC T =SOC L -Δ soc This is used to control and reduce the SOC value when exiting pure electric mode, ensuring that the vehicle remains in pure electric mode for a longer period of time; such as the power consumption P of high-voltage accessories. H If the voltage is raised to the limit (which can be determined through calibration), then it should be restored to the original SOC. L Values should be prioritized to meet energy management needs.
[0044] Another part of the control strategy, based on the vehicle's power requirements, determines the additional power Px that the engine needs to supplement beyond the available power provided by the battery. This is calculated using the universal formula for torque-power ratio, T = 9550P / n. Based on the engine's universal characteristics, the optimal fuel consumption speed at a given power output is determined, minus a set low speed Δ. n The desired engine speed and corresponding torque value are determined by reducing engine speed to meet power requirements and achieve a quieter operation. The torque point at this speed satisfies power needs but falls outside the optimal fuel consumption range, sacrificing some fuel economy. Considering that higher vehicle speeds result in greater external noise under normal driving conditions, reducing engine speed for quieter operation is not ideal at higher speeds. Therefore, a lower engine speed value Δ can be set. n The torque is relatively low, which reduces the upper limit of high fuel consumption; at lower vehicle speeds, the corresponding engine speed is also relatively low. n Increase the size to achieve a better noise reduction effect, as shown in Table 1. Δ n This can be determined through calibration. The engine's universal characteristics, torque and speed at a fixed power output, allow for torque values at lower speeds to meet torque requirements, but their fuel consumption is not optimal, as shown in Table 2. In principle, based on power requirements, the point with the lowest speed that meets torque requirements should be selected for control. Simultaneously, automatic exit conditions are designed: when the vehicle speed exceeds the judgment speed V0 for a duration greater than T1; or the accelerator pedal travel exceeds P1; or the accelerator pedal travel exceeds P2 more than N2 times; or the accelerator pedal travel exceeds P3 more than N3 times (judgment conditions can be finely designed for different short-term high torque demands), based on the principle of prioritizing driver needs, the system automatically exits silent mode and sends an exit prompt message to the display module. After exiting, the system enters the automatic recovery condition judgment. If the low-speed driving conditions defined by the driving condition judgment module are met, the system automatically enters silent mode and prompts the driver that silent mode has been entered; this continues until the current driving cycle ends or the silent mode is manually turned off, at which point the automatic recovery condition judgment will not re-enter.
[0045] Table 1 SOC T calculate
[0046]
[0047] Table 2 Δ at different vehicle speeds n set up
[0048]
[0049] The engine management module receives target speed and target torque commands calculated by the energy management module, comprehensively judges the engine operating status, and executes speed and torque control. This function requires joint debugging with the energy management module, and the specific control parameters are determined through testing and calibration. Table 3 shows the engine's speed, torque, and fuel consumption under constant power conditions.
[0050] Table 3. Example of engine universal characteristics at constant power: speed, torque, and fuel consumption.
[0051]
[0052]
[0053] Example 2
[0054] This embodiment provides a method for controlling the silent mode when a range-extended vehicle is in operation, including:
[0055] S1. The driving condition judgment module determines whether the driving condition meets the requirements of low-speed driving based on the received vehicle speed signal and accelerator pedal signal, and the stopping time and frequency information. The specific method for determining whether the driving condition meets the requirements of low-speed driving is as follows:
[0056] Set the vehicle speed V0 to be judged. If the vehicle does not exceed V0 within the time T0 period, and the number of times the vehicle speed is 0 during this period exceeds N0; define the small throttle travel P0. If the throttle travel exceeds P0 or the number of times the throttle travel exceeds P1 within the time T0 period is N1, it is judged to be in a low-speed driving condition.
[0057] S2. If it is determined that the driving conditions are suitable for low-speed driving, a prompt signal is sent to the prompt module to indicate whether to enter silent mode, and the prompt module prompts the driver.
[0058] S3. The driver control mode selection module enters silent mode;
[0059] S4. The energy management module receives the instruction from the mode selection module, executes the silent mode control, and calculates the target speed and target torque;
[0060] The energy management module's silent mode control is divided into two parts, as detailed below:
[0061] The first part considers maximizing the use of pure electric mode; when the power battery SOC is lower than a certain value... L When the battery is in silent mode, it will exit pure electric mode and enter range-extended mode, starting the engine to participate in power generation; the design reduces the SOC of the power battery that triggers range-extended mode in silent mode. L The value is based on the current power consumption P of the high-voltage accessories. H The power consumption P of the high-voltage accessory is designed. H Equal to the power P of DC-DC DCDC PTC power P PTC The power P of the compressor AC The sum of, i.e., P H =P DCDC +P PTC +P AC Set Δ socCalculate the target SOC for exiting pure electric mode. T SOC T =SOC L -Δ soc This is used to control and reduce the SOC value when exiting pure electric mode, ensuring that the vehicle remains in pure electric mode for a longer period of time; such as the power consumption P of high-voltage accessories. H If the elevation reaches the limit, it will revert to the original SOC. L Values should be prioritized to meet energy management needs.
[0062] This section controls the conditions for exiting pure electric mode, i.e., the SOC value. For example, under normal circumstances, the pure electric mode is exited when the SOC reaches 20%. After calculating the power consumption of the high-voltage system, if the consumption is relatively low, the pure electric mode is exited at 20% SOC and then adjusted to 18% before exiting. This can extend the pure electric operation time and range, achieving a quieter operation. The final parameter obtained is the SOC value that controls the exit from pure electric mode.
[0063] The second part, based on the vehicle's power requirements, determines the additional power Px that the engine needs to supplement beyond the available power provided by the battery. This is calculated using the universal formula for torque-power ratio, T = 9550P / n. Based on the engine's universal characteristics, the optimal fuel consumption speed at a given power output is determined by subtracting the set speed offset value Δ. n The set RPM corresponds to a specific torque value, aiming to reduce RPM while meeting power requirements and achieving a quieter operation. The torque point at this RPM satisfies power needs but falls outside the optimal fuel consumption range, sacrificing some fuel economy. Considering that higher vehicle speeds result in greater external noise under normal driving conditions, reducing RPM for quieter operation is less effective at higher speeds; therefore, a lower RPM value Δ is set. n The torque is relatively low, which reduces the upper limit of high fuel consumption; at lower vehicle speeds, the corresponding engine speed is also relatively low. n To achieve better noise reduction, the engine's torque and speed are adjusted based on its universal characteristics at a fixed power output. Lower speeds can meet torque requirements, but fuel consumption is not optimal. Therefore, the engine is controlled at the lowest speed that meets torque requirements, based on power needs. Automatic exit conditions are designed: when the vehicle speed exceeds the judged speed V0 for a duration greater than T1; or the accelerator pedal travel exceeds P1; or the accelerator pedal travel exceeds P2 more than N2 times; or the accelerator pedal travel exceeds P3 more than N3 times, based on the principle of prioritizing driver needs, the engine automatically exits the quiet mode and sends an exit notification to the notification module. After exiting, the system enters an automatic recovery condition check. If the low-speed driving conditions defined by the driving condition judgment module are met, the engine automatically re-enters quiet mode and notifies the driver that it has entered quiet mode. This automatic recovery condition check will not re-enter until the current driving cycle ends or the quiet mode is manually closed.
[0064] This section first controls the engine speed and torque. Meeting the torque requirement is the primary condition, and based on this, a lower speed point is selected. According to the universal property, this point satisfies the requirements for quietness and torque, but at the expense of fuel consumption. At the same time, the degree of speed reduction is determined according to the vehicle speed. The speed reduction is slightly less at higher vehicle speeds, resulting in relatively better torque and fuel consumption. Finally, the target torque and target speed are obtained for the engine.
[0065] Secondly, it controls the conditions for exiting and resuming silent mode; based on the collected driver operation information, it determines whether to enter medium-high speed driving or high torque driving conditions, and then exits silent mode; the final result is automatic control of the exit and resumption of silent mode, achieving no operation and meeting driving needs.
[0066] S5. The engine management module receives the target speed and target torque commands calculated by the energy management module, comprehensively judges the engine operating status, and executes speed control and torque control.
[0067] In summary, this invention can prompt the driver to enter a quiet mode, keeping the engine running at a lower speed range as much as possible to reduce engine noise, improve the overall vehicle NVH level under low-speed driving and occasional short-term acceleration conditions, and enhance the driving experience.
[0068] Example 3
[0069] In this embodiment, V0 = 60 km / h, T0 = 10 min, N0 = 2, P0 = 50%, N p0 =2, P H =3kW, SOC L =20%; T1=10s, P1=90%, P2=80%, N2=2, P3=70%, N3=3, rotational speed Δ=250rpm; Taking the vehicle speed of 20km / h in Table 1 and the required power of 30kW in Table 2 as an example, the method described in Example 2 will be introduced.
[0070] During vehicle operation, driving information is received in real time. If the vehicle speed remains below 60 km / h for more than 10 minutes, the vehicle speed drops to 0 more than twice, and the accelerator pedal travel exceeds 50% more than twice, the display module will issue a prompt asking whether to enter silent mode. The driver can enter silent mode by operating a physical switch or a virtual switch on the main screen. After entering silent mode, the high-voltage accessory power of 3 kW is calculated, and the State of Charge (SOC) is determined by referring to a table. T=20% - 2% = 18%, then the vehicle will continue to operate in pure electric mode when the SOC of the power battery is greater than 18%. When the SOC of the power battery is less than 18%, or when the vehicle needs the engine to intervene in generating electricity based on driving needs, the energy management module controls the engine speed to maintain at 1500 rpm, and responds to the driver's torque demand according to the engine torque curve at this speed. This keeps the engine noise at a low level and improves the driving experience, but the fuel consumption will be slightly higher than the torque point at 2000 rpm, and the engine is not operating at the optimal fuel consumption line. If the vehicle speed is greater than 60 km / h for more than 10 seconds, or the driver uses the accelerator pedal more than 90%, or the accelerator pedal is more than 80% more than twice, or the accelerator pedal is more than 70% more than three times, the vehicle will automatically exit the silent mode and send an exit prompt to the display module.
[0071] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the scope of protection of the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, any person skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention within the scope of the technology disclosed in the present invention. These simple modifications are all within the scope of protection of the present invention.
[0072] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.
[0073] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.
Claims
1. A method for controlling the noise level in a silent mode when a range-extended vehicle is in operation, characterized in that, include: The driving condition judgment module determines whether the driving condition meets the requirements based on the received vehicle speed signal, accelerator pedal signal, and parking time and frequency information. If the system determines that the driving conditions are suitable for low-speed driving, it sends a prompt signal to the prompt module asking whether to enter silent mode, and the prompt module then prompts the driver. The driver control mode selection module enters silent mode; The energy management module receives instructions from the mode selection module, executes the control to enter silent mode, and calculates the target speed and target torque; The engine management module receives the target speed and target torque commands calculated by the energy management module, comprehensively judges the engine operating status, and executes speed control and torque control. The energy management module's silent mode control is divided into two parts, as detailed below: The first part considers maximizing the use of pure electric mode; when the power battery SOC is lower than a certain value... L When the battery is in silent mode, it will exit pure electric mode and enter range-extended mode, starting the engine to participate in power generation; the design reduces the SOC of the power battery that triggers range-extended mode in silent mode. L The value is based on the current power consumption P of the high-voltage accessories. H The power consumption P of the high-voltage accessory is designed. H Equal to the power P of DC-DC DCDC PTC power P PTC The power P of the compressor AC The sum of, i.e., P H =P DCDC +P PTC +P AC Set Δ soc Calculate the target SOC for exiting pure electric mode. T SOC T =SOC L -Δ soc This is used to control and reduce the SOC value when exiting pure electric mode, ensuring that the vehicle remains in pure electric mode for a longer period of time; such as the power consumption P of high-voltage accessories. H If the elevation reaches the limit, it will revert to the original SOC. L Values should be prioritized to meet energy management needs. The second part, based on the vehicle's power requirements, determines the additional power Px that the engine needs to supplement beyond the available power provided by the battery. This is calculated using the universal formula for torque-power ratio, T = 9550P / n. Based on the engine's universal characteristics, the optimal fuel consumption speed at a given power output is determined by subtracting the set speed offset value Δ. n The engine speed at which the torque value is lowered is used to achieve a quieter operation while still meeting power requirements. The torque point at this speed satisfies power needs but falls outside the optimal fuel consumption range, sacrificing some fuel economy. Considering that under normal driving conditions, higher speeds result in greater external noise, the noise reduction effect of lowering the engine speed is not ideal at higher speeds; therefore, a speed offset value Δ is set. n The torque is relatively small, which corresponds to a smaller input torque, thus reducing the upper limit of high fuel consumption; at lower vehicle speeds, the corresponding speed deviation value Δ n To achieve better noise reduction, the torque and speed of the engine under fixed power are increased. Lower speed torque can meet the torque requirement, but its fuel consumption is not optimal. Based on the power requirement, the point with the lowest speed that meets the torque requirement is selected for control. At the same time, an automatic exit condition is designed. When the vehicle speed is greater than the judged vehicle speed V0 and the duration is greater than T1; or the accelerator pedal travel is greater than P1; or the accelerator pedal travel is greater than P2 for more than N2 times; or the accelerator pedal travel is greater than P3 for more than N3 times, based on the principle of prioritizing the driver's needs, the silent mode is automatically exited, and an exit prompt message is sent to the prompt module. After exiting, the automatic recovery condition judgment is entered. If the low-speed driving conditions defined by the driving condition judgment module are met, the silent mode is automatically entered, and the driver is prompted that the silent mode has been entered. The automatic recovery condition judgment will not be entered again until the current driving cycle ends or the silent mode is manually turned off.
2. The control method for a silent mode of a range-extended vehicle during operation according to claim 1, characterized in that, The specific method for determining whether a driving condition meets the requirements is as follows: Set a speed check value V0. If the vehicle does not exceed V0 within time T0, and the number of times the vehicle speed is 0 during that time exceeds N0; define... If the throttle travel P0 exceeds P0 or the number of times N1 exceeds P1 within the time T0 is greater than a certain number, it is determined that the vehicle is in a low-speed driving condition.
3. A control system for a silent mode in a range-extended vehicle during operation, used to implement the control method for a silent mode in a range-extended vehicle during operation as described in claim 1, characterized in that, include: The prompt module is used to prompt the driver; The mode selection module is used to select the mode; The driving condition judgment module is used to determine whether the driving conditions are suitable for low-speed driving. If the conditions are met, a prompt signal is sent to the prompt module to indicate whether to enter silent mode. The function selection module is used to control whether to enter silent mode; The energy management module receives instructions from the mode selection module and executes the control to enter or exit silent mode. The engine management module receives the target speed and target torque commands calculated by the energy management module, comprehensively judges the engine operating status, and executes speed control and torque control. The driving condition judgment module is connected to the prompt module and the energy management module; the energy management module is connected to the mode selection module and the engine management module.
4. The control system for a silent mode during driving of a range-extended vehicle according to claim 3, characterized in that, The driving condition judgment module receives vehicle speed signals and accelerator pedal signals, and determines whether the driving condition meets the requirements based on the stopping time and frequency information.
5. The control system for a silent mode during driving of a range-extended vehicle according to claim 3, characterized in that, The function selection module supports both turning the prompt function on and off. When turned off, it will no longer enter the driving condition judgment and will not issue a prompt message asking whether to enter silent mode. The function switch can be turned on when needed.