Vehicle brake noise reduction method, device, equipment and storage medium

Abstract

The application belongs to the technical field of vehicle control, and discloses a vehicle braking noise reduction method, device, equipment and storage medium. The application obtains the current vehicle speed when the vehicle enters the braking state, obtains the current generator speed when the current vehicle speed reaches the mode switching speed, obtains the target negative torque of the generator according to the current generator speed, adjusts the torque of the generator to the target negative torque, so that the engine is in the no-load state, whether the driving mode of the vehicle changes is judged through the vehicle speed, the current generator speed is directly obtained, the speed of the engine is slowly reduced through the negative torque of the generator corresponding to the generator speed, so that the engine is smoothly unloaded, the impact between the engine and the fixed part is reduced, and the purpose of reducing the NVH in the switching process is achieved.

Description

Technical Field

[0001] This invention relates to the field of vehicle control technology, and in particular to a method, apparatus, device, and storage medium for reducing vehicle braking noise. Background Technology

[0002] As hybrid vehicles become the mainstream, especially HEV models, which can achieve both engine-driven and generator-driven modes, they can ensure strong power while also achieving low fuel consumption. However, these vehicles still have drawbacks, especially during vehicle braking, where unexpected NVH problems can occur due to the selection of drive mode and changes in control logic.

[0003] Existing solutions employ passive isolation measures such as suspension and adjustment to reduce noise. However, this approach is not effective in reducing noise and cannot address the noise problem at its transmission path.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The main objective of this invention is to provide a vehicle braking noise reduction method, apparatus, device, and storage medium, aiming to solve the technical problem that the prior art cannot reduce noise from the transmission path.

[0006] To achieve the above objectives, the present invention provides a vehicle braking noise reduction method, which is applied to a hybrid electric vehicle. The hybrid electric vehicle includes an engine and a generator, wherein the generator is directly connected to the output shaft of the engine. The method includes the following steps:

[0007] When the vehicle enters braking mode, obtain the current vehicle speed;

[0008] When the current vehicle speed reaches the mode switching speed, the current generator speed is obtained;

[0009] The target negative torque of the generator is obtained based on the current generator speed.

[0010] The torque of the generator is adjusted to the target negative torque so that the engine is in an unloaded state.

[0011] Optionally, the target negative torque includes a first target negative torque and a second target negative torque;

[0012] The step of obtaining the target negative torque of the generator based on the current generator speed includes:

[0013] The current generator speed is detected, and when the generator speed is greater than or equal to a first speed, the torque of the generator is adjusted to a first target negative torque;

[0014] When the generator speed is greater than or equal to the second speed and less than the first speed, the torque of the generator is adjusted to the second target negative torque, the absolute value of the first target negative torque is greater than the absolute value of the second target negative torque, and the first speed is greater than the second speed.

[0015] Optionally, after obtaining the current vehicle speed when the vehicle enters braking state, the method further includes:

[0016] When the current vehicle speed is greater than the mode switching speed, the current vehicle speed is set as the initial speed;

[0017] After a preset time interval, the current vehicle speed is obtained again, and the current vehicle speed is set as the final speed;

[0018] The acceleration of the vehicle is obtained based on the initial velocity, the final velocity, and the preset time interval;

[0019] The target negative torque of the generator is determined based on the acceleration.

[0020] Optionally, determining the target negative torque of the generator based on the acceleration includes:

[0021] When the acceleration is less than zero, the torque of the generator is adjusted to the third target negative torque based on the acceleration.

[0022] Optionally, adjusting the torque of the generator obtained based on the acceleration to a third target negative torque includes:

[0023] The driving environment type of the vehicle is detected to obtain the current driving environment type;

[0024] The third target negative torque is obtained based on the current driving environment type and the acceleration.

[0025] Optionally, after adjusting the torque of the generator to the target negative torque to reduce the engine speed to an unloaded state, the method further includes:

[0026] The vehicle's current speed is detected; if the current speed is greater than the mode switching speed, the vehicle's driving environment is detected.

[0027] When the vehicle's driving environment is a preset environment, the negative torque required by the generator is obtained based on the current vehicle speed, and the negative torque is applied to the generator.

[0028] Optionally, before obtaining the current vehicle speed when the vehicle enters braking state, the method further includes:

[0029] The system detects the opening degree and braking duration of the vehicle's brake pedal. When the brake pedal opening degree is greater than a preset opening degree or the braking duration is greater than a preset duration, the system enters a braking state and executes the step of obtaining the current vehicle speed.

[0030] Furthermore, to achieve the above objectives, the present invention also proposes a vehicle braking noise reduction device, the vehicle braking noise reduction device comprising:

[0031] A speed acquisition device is used to acquire the current vehicle speed when the vehicle enters a braking state;

[0032] The speed acquisition device is used to acquire the current generator speed when the current vehicle speed reaches the mode switching speed;

[0033] A torque generation device is used to obtain the target negative torque of the generator based on the current generator speed.

[0034] A torque adjustment device is used to adjust the torque of the generator to the target negative torque so that the engine is in an unloaded state.

[0035] Furthermore, to achieve the above objectives, the present invention also proposes a vehicle braking noise reduction device, which includes: a memory, a processor, and a vehicle braking noise reduction program stored in the memory and executable on the processor, wherein the vehicle braking noise reduction program is configured to implement the steps of the vehicle braking noise reduction method described above.

[0036] In addition, to achieve the above objectives, the present invention also proposes a storage medium storing a vehicle braking noise reduction program, which, when executed by a processor, implements the steps of the vehicle braking noise reduction method described above.

[0037] This invention obtains the current vehicle speed when the vehicle enters braking mode, and then obtains the current generator speed when the current vehicle speed reaches the mode switching speed. Based on the current generator speed, a target negative torque for the generator is obtained, and the generator torque is adjusted to the target negative torque to put the engine in an unloaded state. This achieves the goal of determining whether the vehicle's driving mode has changed by measuring the vehicle speed, thereby directly obtaining the current generator speed, and using the negative torque corresponding to the generator speed to slowly reduce the engine speed, thus smoothly unloading the engine and reducing the impact between the engine and fixed components, thereby achieving the purpose of reducing NVH during the switching process. Attached Figure Description

[0038] Figure 1This is a schematic diagram of the structure of a vehicle braking noise reduction device in the hardware operating environment involved in the embodiments of the present invention;

[0039] Figure 2 This is a flowchart illustrating the first embodiment of the vehicle braking noise reduction method of the present invention;

[0040] Figure 3 This is a noise diagram before optimization in an embodiment of the vehicle braking noise reduction method of the present invention;

[0041] Figure 4 This is an optimized effect diagram of an embodiment of the vehicle braking noise reduction method of the present invention;

[0042] Figure 5 This is an optimized noise diagram of an embodiment of the vehicle braking noise reduction method of the present invention;

[0043] Figure 6 This is a flowchart illustrating the second embodiment of the vehicle braking noise reduction method of the present invention;

[0044] Figure 7 This is a structural block diagram of the first embodiment of the vehicle braking noise reduction device of the present invention.

[0045] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0046] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0047] Reference Figure 1 , Figure 1 This is a schematic diagram of the vehicle braking noise reduction device structure in the hardware operating environment involved in the embodiments of the present invention.

[0048] like Figure 1As shown, the vehicle braking noise reduction device may include: a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display screen or an input unit such as a keyboard; optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a Wi-Fi interface). The memory 1005 may be a high-speed random access memory (RAM) or a stable non-volatile memory (NVM), such as a disk drive. The memory 1005 may also optionally be a storage device independent of the aforementioned processor 1001.

[0049] Those skilled in the art will understand that Figure 1 The structure shown does not constitute a limitation on vehicle braking noise reduction equipment, and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0050] like Figure 1 As shown, the memory 1005, which serves as a storage medium, may include an operating system, a network communication module, a user interface module, and a vehicle braking noise reduction program.

[0051] exist Figure 1 In the vehicle braking noise reduction device shown, the network interface 1004 is mainly used for data communication with the network server; the user interface 1003 is mainly used for data interaction with the user; the processor 1001 and the memory 1005 in the vehicle braking noise reduction device of the present invention can be set in the vehicle braking noise reduction device. The vehicle braking noise reduction device calls the vehicle braking noise reduction program stored in the memory 1005 through the processor 1001 and executes the vehicle braking noise reduction method provided in the embodiment of the present invention.

[0052] This invention provides a method for reducing vehicle braking noise, referring to... Figure 2 , Figure 2 This is a flowchart illustrating the first embodiment of a vehicle braking noise reduction method according to the present invention.

[0053] In this embodiment, the vehicle braking noise reduction method includes the following steps:

[0054] Step S10: When the vehicle enters braking mode, obtain the current vehicle speed;

[0055] It should be noted that braking state refers to the state in which the vehicle is currently in the state of having the brake pedal pressed. In this state, the vehicle speed will have a significant decreasing trend, causing the vehicle to change from a high speed state to a low speed state.

[0056] In its implementation, the vehicle braking noise reduction device detects the vehicle's driving status, including the opening of the brake pedal. During normal driving, the brake pedal opening is 0, and the brake pedal is in its initial state. When the brake pedal opening changes and becomes non-zero, it indicates that the brake pedal has been pressed, and the vehicle switches from normal driving to braking. When entering braking state, the vehicle's current speed is obtained.

[0057] Step S20: When the current vehicle speed reaches the mode switching speed, obtain the current generator speed;

[0058] It should be noted that the mode switching speed refers to the condition under which a vehicle switches from engine-driven to generator-driven. In other words, when the vehicle's speed reaches the mode switching speed, it can switch from engine-driven to generator-driven, or vice versa.

[0059] In its implementation, the vehicle braking noise reduction equipment detects the vehicle's speed during operation. When the vehicle is driving normally on the road, it is propelled by the internal combustion engine. When the vehicle enters braking mode, before the speed decreases to the point where it needs to switch to pure electric mode, the energy drive is in series mode: the engine's generator charges the battery pack, which in turn powers the electric motor to drive the vehicle. When the vehicle speed is detected to have decreased to a pre-set mode-switching speed, the driving mode changes, switching to EV pure electric mode. Simultaneously, the generator's rotational speed at the moment of mode switching is acquired. For example, if the vehicle's mode switching speed is 10 km / h, when the vehicle speed is above 10 km / h, it is in hybrid mode, and when the speed is at or below 10 km / h, it is in pure electric (EV) mode. When the vehicle speed drops from above 10 km / h to below 10 km / h due to braking, the engine's operating mode changes. The engine, which was originally running at high speed to drive the generator, now does not need to drive it. However, the engine still has a relatively high operating speed, which can cause significant impact and collision with fixed components, resulting in noise. Therefore, during mode switching, the engine needs to be smoothly unloaded. This requires providing a force that acts as a resistance to the engine. This can be achieved by reducing the engine's movement through the output shaft between the engine and the generator. Therefore, when the vehicle speed reaches the mode switching speed, the generator's rotational speed is obtained to determine the magnitude of the negative torque applied.

[0060] Step S30: Obtain the target negative torque of the generator based on the current generator speed;

[0061] It should be noted that the target negative torque refers to the torque that acts on the generator to create resistance. There is a mapping relationship between the generator speed and the target negative torque to be applied to the generator. Each generator speed can correspond to a target negative torque to cope with various speed conditions.

[0062] In practical implementation, the vehicle braking noise reduction device looks up the correspondence table between the obtained generator speed and the target negative torque. Based on the mapping relationship recorded in the table, the applied torque of the generator can be adjusted in real time according to the generator speed. The mapping relationship table between the generator speed and the target negative torque can be stored in the storage medium of the vehicle or the vehicle braking noise reduction device. When the vehicle braking noise reduction device needs to obtain the target negative torque based on the generator speed, it can read the corresponding mapping relationship from the storage medium. For example, the mapping relationship table between the current generator speed and the generator's target torque is shown in Table 1.

[0063] Table 1:

[0064] Generator torque / Nm -4 -10

[0065] When the generator speed is greater than 1325 rpm, a target negative torque of -10 Nm is uniformly applied to the generator. That is, regardless of whether the generator speed is 1500 rpm or 1326 rpm, since it is greater than 1325 rpm, a negative torque of -10 Nm is applied. When the generator speed is detected to be between 500 rpm and 1325 rpm, a negative torque of -4 Nm can be applied. Of course, this correspondence between generator speed and generator torque can also be other values. This embodiment only uses the above data as an example for illustration and does not limit the correspondence between speed and torque.

[0066] Step S40: Adjust the torque of the generator to the target negative torque so that the engine is in an unloaded state.

[0067] It should be noted that the no-load state refers to the engine's working state. At this time, the engine no longer drives the generator and is in a state of idling. The engine is still working and has not completely stopped rotating.

[0068] In practical implementation, since the engine and generator are directly connected via the output shaft, in series mode, the engine rotation drives the generator to rotate and generate electricity. Therefore, the generator speed can be affected by controlling the generator end. Thus, the engine speed can be influenced by the target negative torque obtained from the generator speed. This target negative torque can be applied to the generator. Because the engine and generator are directly connected via the output shaft, applying negative torque to the generator will cause the output shaft to reduce the engine speed, allowing the crankshaft and other moving parts inside the engine to unload more smoothly during engine shutdown. This reduces the impact and collision between the moving parts and fixed components. (Refer to...) Figure 3 , Figure 4 , Figure 5 Without applying negative torque to the generator, there is very noticeable noise inside the vehicle; after applying negative torque to the generator, such as Figure 4 As shown, at time 11:89 when the generator speed is 1325.90 rpm, the generator torque is -12.00 Nm, and the applied torque is -10 Nm. As the torque is continuously applied, when the generator speed reaches 346.00 rpm, the corresponding generator torque is -4.00 Nm. It can be seen that the generator torque continuously increases as the generator speed decreases. Meanwhile, based on the simulated noise in the driver's right ear, such as... Figure 5As shown, there are no obvious impact peaks or abnormal noises. Therefore, by applying negative torque to the generator, the NVH problems caused by the switching of braking modes can be reduced.

[0069] This embodiment obtains the current vehicle speed when the vehicle enters braking mode, and obtains the current generator speed when the current vehicle speed reaches the mode switching speed. Based on the current generator speed, the target negative torque of the generator is obtained, and the generator torque is adjusted to the target negative torque to put the engine in an unloaded state. This achieves the goal of determining whether the vehicle's driving mode has changed by measuring the vehicle speed, and then directly obtaining the current generator speed. By adjusting the generator speed with the corresponding negative torque, the engine speed is slowly reduced, thereby smoothly unloading the engine and reducing the impact between the engine and the fixed components, thus achieving the purpose of reducing NVH during the switching process.

[0070] refer to Figure 6 , Figure 6 This is a flowchart illustrating a second embodiment of a vehicle braking noise reduction method according to the present invention.

[0071] Based on the first embodiment described above, the vehicle braking noise reduction method of this embodiment includes the following in step S30:

[0072] Step 301: Detect the current generator speed. When the generator speed is greater than or equal to the first speed, adjust the generator torque to the first target negative torque.

[0073] Step 302: When the generator speed is greater than or equal to the second speed and less than the first speed, the torque of the generator is adjusted to the second target negative torque, the absolute value of the first target negative torque is greater than the absolute value of the second target negative torque, and the first speed is greater than the second speed.

[0074] It should be noted that the first speed and the second speed are different speeds of the generator, with the first speed being greater than the second speed. The first target negative torque and the second target negative torque correspond to the first speed and the second speed, respectively.

[0075] In practical implementation, when the vehicle's braking noise reduction equipment switches modes, it acquires the current speed of the vehicle's generator and monitors it in real time. Based on the generator's speed, it adjusts the negative torque applied to the generator. When the vehicle decelerates from a higher speed to a lower speed, the generator's speed transitions from a higher speed to a lower speed. Therefore, when initially entering EV pure electric mode, the generator has a relatively high speed, and the corresponding engine speed is also relatively high. Thus, the generator's speed can be correlated with the torque in a pre-set torque application strategy. When the generator's speed is detected... When the speed is greater than the first rotational speed, the first target negative torque corresponding to the first rotational speed can be obtained. The generator torque is then adjusted to the first target negative torque to reduce the engine speed drop, allowing the engine to more smoothly unload the torque generated during rapid rotation. As the generator continuously applies the first target negative torque, its own speed also decreases. When the generator speed drop is detected to be less than the first rotational speed, the generator speed needs to be compared with the second rotational speed. When the generator speed is between the first and second rotational speeds, the generator speed can be adjusted to the second target negative torque to further counteract the engine rotation and reduce the rotation amplitude. It is also understood that as the generator continuously applies negative torque, the engine rotation amplitude gradually decreases. Therefore, as the generator speed decreases, the corresponding torque also gradually decreases to adapt to the engine speed drop trend. In the actual torque selection process, other corresponding relationships can be set; this embodiment does not limit this.

[0076] To further ensure noise minimization, predictions can be made in advance based on vehicle driving conditions, therefore the following steps are also included:

[0077] When the current vehicle speed is greater than the mode switching speed, the current vehicle speed is set as the initial speed;

[0078] After a preset time interval, the current vehicle speed is obtained again, and the current vehicle speed is set as the final speed;

[0079] The acceleration of the vehicle is obtained based on the initial velocity, the final velocity, and the preset time interval;

[0080] The target negative torque of the generator is determined based on the acceleration.

[0081] It should be noted that the initial velocity refers to the velocity acquired earlier in two separate acquisitions of the vehicle's current speed, while the final velocity is the velocity acquired later in two separate acquisitions of the vehicle's current speed. For example, if vehicle speeds v1, v2, and v3 are acquired at three different times, v1 is used as the initial velocity and v2 as the final velocity in the first time interval, while v2 is used as the initial velocity and v3 as the final velocity in the second time interval. Acceleration refers to the change in vehicle speed between two acquisitions. Since vehicle speed is constantly changing, acceleration can be positive or negative. The preset time refers to the time interval between two acquisitions of vehicle speed, which can be 1 second, 2 seconds, 0.5 seconds, etc. The specific time interval is determined according to the actual situation, and this embodiment does not impose any restrictions on it.

[0082] In the specific implementation, when the vehicle speed is detected to be greater than the mode switching speed, the current vehicle speed is acquired and set as the initial speed. Since the vehicle is in a braking state at this time, the speed is continuously decreasing. Therefore, the speed acquired again after a preset interval is set as the final speed, which is less than the initial speed. The acceleration during this time interval can then be calculated based on the initial speed, final speed, and preset interval. For example, if the initial speed is 30 km / h, the final speed is 24 km / h, and the preset time interval is 1 second, then the acceleration is (24 km / h - 30 km / h) / 1 second = -1.67 m / s². 2 Similarly, after a preset time interval, the vehicle speed is acquired again, and the acquired speed is set as the new final speed. The original final speed is set as the new initial speed, and so on. Since the speed change does not strictly follow the same downward trend, the rate of speed decrease can be determined based on the obtained acceleration. Based on the rate of speed decrease, the target torque is applied to the generator to reduce the engine speed in advance.

[0083] To further adjust the generator torque, the following steps are also included:

[0084] When the acceleration is less than zero, the torque of the generator is adjusted to the third target negative torque based on the acceleration.

[0085] It should be noted that the third target negative torque is the negative torque applied to the generator before the vehicle enters EV pure electric mode. Its function is to reduce the engine speed before entering pure electric mode, so that the generator can more quickly and smoothly stop the engine in EV pure electric mode. The so-called stopping refers to unloading the engine, and the engine is in an idling state.

[0086] In practice, the vehicle's acceleration during driving is first determined based on its speed while braking. Since there's a time interval between two speed measurements, the vehicle might briefly accelerate during this period. In such cases, the acceleration might be positive, meaning the final speed is greater than the initial speed. In this situation, it cannot be assumed that the vehicle has switched to EV pure electric mode, and therefore, there's no need to unload the engine prematurely. However, when the acceleration is less than zero, it indicates that the final speed is less than the initial speed. In this case, it can be assumed that the vehicle's current driving intention is deceleration, and a mode switch is possible. The larger the absolute value of the acceleration, the stronger this trend or intention, and the greater the negative torque that needs to be applied in advance, thus reducing NVH issues during mode switching.

[0087] To further determine the third target negative torque, the following steps are also included:

[0088] The driving environment type of the vehicle is detected to obtain the current driving environment type;

[0089] The third target negative torque is obtained based on the current driving environment type and the acceleration.

[0090] It should be noted that the driving environment type refers to the current driving environment of the vehicle, including possible road congestion, slow traffic or other sudden dangerous situations that may occur during the vehicle's operation.

[0091] In practice, during vehicle operation, the driving environment can be determined by the driving environment detection equipment installed on the vehicle. Different driving environments have different tolerance levels for different NVH problems. Before solving NVH problems, safety needs to be ensured. For example, when the vehicle is in slow or congested traffic, the vehicle speed is not high, and it frequently enters braking mode, especially when the vehicle is in EV pure electric mode for a long time. When the vehicle speed increases to a speed that can achieve hybrid mode, the vehicle can be temporarily controlled to not enter hybrid mode, but to operate in pure electric mode at a speed higher than the mode switching speed. After a period of time, it can be restored to hybrid mode to prevent the vehicle from frequently switching between the two modes and causing the engine to be in a cycle of loading and unloading, which can reduce the number of NVH problems. If an obstacle is suddenly detected ahead that affects driving safety, the vehicle needs to be stopped in the shortest possible time. At this time, the corresponding target negative torque should be 0 or other small values. This value can be determined according to the actual situation. This embodiment does not impose any restrictions on this. During normal driving, the vehicle braking noise reduction can make a preliminary judgment on the surrounding environment through environmental detection equipment and determine the target negative torque to be applied to the generator based on the current road condition information. The worse the surrounding environment, the greater the target negative torque applied and the lower the speed provided by the engine to the generator.

[0092] To further reduce NVH issues, the following steps are also included:

[0093] The vehicle's current speed is detected; if the current speed is greater than the mode switching speed, the vehicle's driving environment is detected.

[0094] When the vehicle's driving environment is a preset environment, the negative torque required by the generator is obtained based on the current vehicle speed, and the negative torque is applied to the generator.

[0095] It should be noted that the preset environment refers to an environment in which the vehicle can travel at the normal speed on the road and the speed can be maintained in a relatively stable driving environment.

[0096] In practice, after applying negative torque to the generator to unload the engine and put it into idling mode, the vehicle's current speed is detected. If the vehicle speed increases and exceeds the mode switching speed, the surrounding environment needs to be assessed to avoid frequent mode switching due to unstable speed. Continuous mode switching can also cause NVH problems. Therefore, when the vehicle's speed fluctuates due to the surrounding environment, and the driving environment is not a preset environment, for example, if the vehicle's mode switching speed is 10 km / h and the current speed increases from 9 km / h to 11 km / h, even though the current speed has exceeded the mode switching speed and the mode switch has been achieved, if the current driving environment cannot allow the vehicle to travel at a normal speed, a negative torque is still applied to the generator to stop the engine and prevent the vehicle from entering pure electric mode due to excessive engine unloading, which would cause NVH problems.

[0097] To further determine the braking mode, the following steps are also included:

[0098] The system detects the opening degree and braking duration of the vehicle's brake pedal. When the brake pedal opening degree is greater than a preset opening degree or the braking duration is greater than a preset duration, the system enters a braking state and executes the step of obtaining the current vehicle speed.

[0099] It should be noted that the opening of the brake pedal can be understood as the degree to which the brake pedal is pressed. The larger the opening of the brake pedal, the greater the braking force. The preset opening refers to the minimum opening of the brake pedal, and the preset duration refers to the minimum identifiable time after the brake pedal is pressed. The preset opening and preset duration can be adjusted according to specific circumstances, and this embodiment does not impose any restrictions on them.

[0100] In practice, when the driver presses the brake pedal, a timer starts to record the duration of the brake pedal press. The force applied to the brake pedal, i.e., the pedal opening, is also detected. Based on the time of the press and the pedal opening, it is determined whether the brake pedal press was intentional or unintentional, preventing accidental braking due to driver error. This allows for control of the generator. Only when the brake pedal press duration exceeds a preset value or the brake pedal opening exceeds a preset value will the braking mode be confirmed, and the vehicle's current speed will be acquired and detected.

[0101] This embodiment achieves engine braking by acquiring the generator's rotational speed and determining the appropriate negative torque to apply to it. To ensure a smoother engine braking, the vehicle's driving status is detected and assessed before entering EV pure electric mode. In cases where mode switching is possible, the vehicle's braking noise reduction equipment intervenes in advance, reducing the engine's operating speed and thus decreasing the initial engine speed during braking, resulting in a faster and smoother engine braking. Furthermore, since frequent switching between modes can lead to frequent NVH (noise, vibration, and harshness) issues, this embodiment also controls mode switching based on the surrounding environment. When driving conditions are unfavorable, frequent switching between hybrid and pure electric modes is avoided as much as possible, reducing the frequency of NVH problems. Additionally, the negative torque applied to the generator is determined based on the surrounding environment and vehicle speed, further reducing the engine speed and addressing NVH issues during mode switching.

[0102] Furthermore, this embodiment of the invention also proposes a storage medium storing a vehicle braking noise reduction program, which, when executed by a processor, implements the steps of the vehicle braking noise reduction method described above.

[0103] Reference Figure 7 , Figure 7 This is a structural block diagram of the first embodiment of the vehicle braking noise reduction device of the present invention.

[0104] like Figure 7 As shown, the vehicle braking noise reduction device proposed in this embodiment of the invention includes:

[0105] The speed acquisition device 10 is used to acquire the current vehicle speed when the vehicle enters a braking state;

[0106] The speed acquisition device 20 is used to acquire the current generator speed when the current vehicle speed reaches the mode switching speed;

[0107] The torque generating device 30 is used to obtain the target negative torque of the generator based on the current generator speed.

[0108] The torque adjustment device 40 is used to adjust the torque of the generator to the target negative torque so that the engine is in an unloaded state.

[0109] This embodiment obtains the current vehicle speed when the vehicle enters braking mode, and obtains the current generator speed when the current vehicle speed reaches the mode switching speed. Based on the current generator speed, the target negative torque of the generator is obtained, and the torque of the generator is adjusted to the target negative torque so that the engine is in an unloaded state. This achieves the goal of determining whether the vehicle's driving mode has changed by measuring the vehicle speed, and then directly obtaining the current generator speed. By adjusting the negative torque corresponding to the generator speed, the engine speed is slowly reduced, thereby smoothly unloading the engine, reducing the impact between the engine and the fixed components, and thus reducing noise during the switching process.

[0110] In one embodiment, the torque generating device 30 is further configured to detect the current generator speed, and when the generator speed is greater than or equal to a first speed, adjust the torque of the generator to a first target negative torque; when the generator speed is greater than or equal to a second speed but less than the first speed, adjust the torque of the generator to a second target negative torque, wherein the absolute value of the first target negative torque is greater than the absolute value of the second target negative torque, and the first speed is greater than the second speed.

[0111] In one embodiment, the speed acquisition device 10 is further configured to, when the current vehicle speed is greater than the mode switching speed, set the current vehicle speed as an initial speed, acquire the current vehicle speed again after a preset time interval, and set the current vehicle speed as an final speed, obtain the acceleration of the vehicle based on the initial speed, the final speed and the preset time interval, and determine the target negative torque of the generator based on the acceleration.

[0112] In one embodiment, the speed acquisition device 10 is further configured to adjust the torque of the generator obtained from the acceleration to a third target negative torque when the acceleration is less than zero.

[0113] In one embodiment, the speed acquisition device 10 is further configured to detect the driving environment type of the vehicle, obtain the current driving environment type, and obtain a third target negative torque based on the current driving environment type and the acceleration.

[0114] In one embodiment, the torque adjustment device 40 is further configured to detect the current vehicle speed, and if the current vehicle speed is greater than the mode switching speed, detect the driving environment of the vehicle, and when the driving environment of the vehicle is a preset environment, obtain the negative torque required by the generator based on the current vehicle speed, and apply the negative torque to the generator.

[0115] In one embodiment, the speed acquisition device 10 is further configured to detect the opening degree and braking duration of the vehicle's brake pedal, and when the brake pedal opening degree is greater than a preset opening degree or the braking duration is greater than a preset duration, enter a braking state and execute the step of acquiring the current vehicle speed.

[0116] It should be understood that the above are merely illustrative examples and do not constitute any limitation on the technical solutions of the present invention. In specific applications, those skilled in the art can make settings as needed, and the present invention does not impose any restrictions on this.

[0117] It should be noted that the workflow described above is merely illustrative and does not limit the scope of protection of this invention. In practical applications, those skilled in the art can select some or all of the workflow to achieve the purpose of this embodiment according to actual needs, and no restrictions are imposed here.

[0118] Furthermore, it should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0119] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0120] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as read-only memory (ROM) / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0121] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A method for reducing vehicle braking noise, characterized in that, The vehicle braking noise reduction method is applied to a hybrid electric vehicle, which includes an engine and a generator, wherein the generator is directly connected to the output shaft of the engine. The vehicle braking noise reduction method includes: When the vehicle enters braking mode, obtain the current vehicle speed; When the current vehicle speed reaches the mode switching speed, the current generator speed is obtained; The target negative torque of the generator is obtained based on the current generator speed. The torque of the generator is adjusted to the target negative torque so that the engine is in an unloaded state; After obtaining the current vehicle speed when the vehicle enters braking mode, the method further includes: When the current vehicle speed is greater than the mode switching speed, the current vehicle speed is set as the initial speed; After a preset time interval, the current vehicle speed is obtained again, and the current vehicle speed is set as the final speed; The acceleration of the vehicle is obtained based on the initial velocity, the final velocity, and the preset time interval; The target negative torque of the generator is determined based on the acceleration.

2. The method as described in claim 1, characterized in that, The target negative torque includes a first target negative torque and a second target negative torque; The step of obtaining the target negative torque of the generator based on the current generator speed includes: The current generator speed is detected, and when the generator speed is greater than or equal to a first speed, the torque of the generator is adjusted to a first target negative torque; When the generator speed is greater than or equal to the second speed and less than the first speed, the torque of the generator is adjusted to the second target negative torque, the absolute value of the first target negative torque is greater than the absolute value of the second target negative torque, and the first speed is greater than the second speed.

3. The method as described in claim 1, characterized in that, Determining the target negative torque of the generator based on the acceleration includes: When the acceleration is less than zero, the torque of the generator is adjusted to the third target negative torque based on the acceleration.

4. The method as described in claim 2, characterized in that, The step of adjusting the torque of the generator obtained based on the acceleration to the third target negative torque includes: The driving environment type of the vehicle is detected to obtain the current driving environment type; The third target negative torque is obtained based on the current driving environment type and the acceleration.

5. The method as described in claim 1, characterized in that, After adjusting the torque of the generator to the target negative torque to reduce the engine speed to an unloaded state, the method further includes: The vehicle's current speed is detected; if the current speed is greater than the mode switching speed, the vehicle's driving environment is detected. When the vehicle's driving environment is not a preset environment, the negative torque required by the generator is obtained based on the current vehicle speed, and the negative torque is applied to the generator.

6. The method according to any one of claims 1-5, characterized in that, Before obtaining the current vehicle speed when the vehicle enters braking state, the process also includes: The system detects the opening degree and braking duration of the vehicle's brake pedal. When the brake pedal opening degree is greater than a preset opening degree or the braking duration is greater than a preset duration, the system enters a braking state and executes the step of obtaining the current vehicle speed.

7. A vehicle braking noise reduction device, characterized in that, The vehicle braking noise reduction device is applied to a hybrid electric vehicle, which includes an engine and a generator; the vehicle braking noise reduction device includes: A speed acquisition device is used to acquire the current vehicle speed when the vehicle enters a braking state; The speed acquisition device is used to acquire the current generator speed when the current vehicle speed reaches the mode switching speed; A torque generation device is used to obtain the target negative torque of the generator based on the current generator speed. A torque adjustment device is used to adjust the torque of the generator to the target negative torque so that the engine is in an unloaded state; After obtaining the current vehicle speed when the vehicle enters braking mode, the method further includes: When the current vehicle speed is greater than the mode switching speed, the current vehicle speed is set as the initial speed; After a preset time interval, the current vehicle speed is obtained again, and the current vehicle speed is set as the final speed; The acceleration of the vehicle is obtained based on the initial velocity, the final velocity, and the preset time interval; The target negative torque of the generator is determined based on the acceleration.

8. A vehicle braking noise reduction device, characterized in that, The device includes: a memory, a processor, and a vehicle braking noise reduction program stored in the memory and executable on the processor, the vehicle braking noise reduction program being configured to implement the steps of the vehicle braking noise reduction method as described in any one of claims 1 to 6.

9. A storage medium, characterized in that, The storage medium stores a vehicle braking noise reduction program, which, when executed by a processor, implements the steps of the vehicle braking noise reduction method as described in any one of claims 1 to 6.

Images