Vehicle control method, controller and vehicle

Abstract

The invention discloses a vehicle control method which comprises the following steps: after a flameout instruction is detected, acquiring a battery instantaneous charging power limit value and flameout charging power under a current working condition; the magnitude relation between the instantaneous charging power and the flameout charging power is judged, if the instantaneous charging power is displayed to be smaller than the flameout charging power, it is indicated that the current battery is full of electricity, and knocking noise cannot be improved by increasing the power generation torque, the vehicle is controlled through a first control strategy, and the first control strategy is used for controlling the opening degree of a throttle valve of an engine. When the instantaneous charging power limit value is not smaller than the flameout charging power, it is indicated that the current battery is not in the full electric quantity state, charging can be continued, under the working condition, the vehicle can be controlled through the first control strategy and / or the second control strategy, and the noise problem is solved. Namely, by controlling the opening degree of the throttle valve and / or controlling the torque of the generator, the rotating speed fluctuation of the engine is reduced, so that the knocking noise is reduced.

Description

Technical Field

[0001] This application relates to the field of automotive technology, specifically to a vehicle control method, a controller, and a vehicle. Background Technology

[0002] Hybrid vehicles include components such as engines, shock absorbers, and generators, and their structure is as follows: Figure 1 As shown in the diagram. The engine crankshaft is bolted to the active end of the shock absorber, which typically uses a torque limiter or a dual-mass flywheel. The passive end of the shock absorber is connected to the input shaft of the generator (P1 motor) via a spline. Due to assembly requirements, the spline is generally clearance-fitted, with a clearance typically between 0-0.12 mm.

[0003] For new energy powertrains, due to the increased rotor inertia of the P1 motor, during engine shutdown, after the engine rapidly cuts off fuel, the crankshaft experiences significant speed fluctuations, reaching up to 200-300 r / min, due to changes in the engine's own resistance. These speed fluctuations are damped by a shock absorber and then transmitted to the generator input shaft connected to the rear. However, because there is a gap between the spline on the driven end of the shock absorber and the generator input shaft, knocking noise is generated at the spline during these speed fluctuations, affecting the user's driving experience. Summary of the Invention

[0004] In view of this, embodiments of this application provide a vehicle control method, controller, and vehicle to solve the problem of knocking noise generated by the splines connecting the engine and generator during engine shutdown.

[0005] To address the above problems, the technical solutions provided in this application are as follows:

[0006] In a first aspect of this application, a vehicle control method is provided, the method comprising:

[0007] In response to the detection of an engine shutdown command, the instantaneous charging power limit of the battery and the charging power after engine shutdown are obtained;

[0008] If the instantaneous charging power limit is less than the engine shutdown charging power, the vehicle is controlled using a first control strategy, which is used to control the throttle opening of the engine.

[0009] If the instantaneous charging power limit is not less than the off-fire charging power, the vehicle is controlled using the first control strategy and / or the second control strategy, wherein the second control strategy is used to control the generator's generating torque.

[0010] In a second aspect of this application, a controller is provided, the controller comprising:

[0011] The acquisition unit is used to acquire the instantaneous charging power limit and the charging power after the engine is turned off in response to the detection of the engine shutdown command.

[0012] The control unit is used to control the vehicle using a first control strategy if the instantaneous charging power limit is less than the engine shutdown charging power. The first control strategy is used to control the throttle opening of the engine.

[0013] The control unit is further configured to control the vehicle using the first control strategy and / or the second control strategy if the instantaneous charging power limit is not less than the off-fire charging power, wherein the second control strategy is used to control the generator's generating torque.

[0014] In a third aspect of this application, a vehicle is provided, the vehicle including the controller, generator and engine described in the second aspect;

[0015] The controller is used to control the generator and the engine;

[0016] The generator is used to charge the vehicle's battery and / or supply power to electrical equipment in the vehicle;

[0017] The engine is used to provide power to the vehicle.

[0018] In a fourth aspect of this application, a computer-readable storage medium is provided, wherein instructions are stored therein, which, when executed on a device, cause the device to perform the vehicle control method described in the first aspect.

[0019] In a fifth aspect of this application, a computer program product is provided that, when the computer program product is run on a computer, causes the computer to perform the vehicle control method described in the first aspect.

[0020] Therefore, the embodiments of this application have the following beneficial effects:

[0021] In this application, upon detecting a shutdown command, the instantaneous battery charging power limit and the shutdown charging power under the current operating conditions are obtained. The relationship between these two values ​​is determined. If the instantaneous charging power is less than the shutdown charging power, it indicates that the battery is currently fully charged, and the knocking noise cannot be improved by increasing the generator torque. In this case, a first control strategy is used to control the vehicle. This first control strategy controls the engine throttle opening. Specifically, by controlling the throttle opening, the engine intake air volume during shutdown is reduced, thereby reducing the engine piston compression cylinder pressure, making the engine's own resistance smoother during shutdown and reducing engine speed fluctuations. When the instantaneous charging power limit is not less than the shutdown charging power, it indicates that the battery is not currently fully charged and can continue charging. Under this condition, the vehicle can be controlled through the first control strategy and / or the second control strategy to improve the noise problem. Specifically, by controlling the throttle opening and / or controlling the generator torque, engine speed fluctuations are reduced, thereby reducing knocking noise. Attached Figure Description

[0022] Figure 1 This application provides a schematic diagram of a hybrid system structure.

[0023] Figure 2 A flowchart of a vehicle control method provided in an embodiment of this application;

[0024] Figures 3-6 This application provides a schematic diagram of a knocking feature during the engine shutdown process.

[0025] Figure 7 A schematic diagram of a controller structure provided in an embodiment of this application;

[0026] Figure 8 This is a schematic diagram of a vehicle structure provided for an embodiment of this application. Detailed Implementation

[0027] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the embodiments of this application will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0028] Currently, during engine shutdown, a knocking noise is generated at the spline due to the gap between the shock absorber's passive end spline and the generator input shaft, causing fluctuations in engine speed and leading to complaints. This problem is particularly noticeable when the engine is shut off while stationary or during low-speed driving, as there is no background noise. To address this issue, some have increased resistance by increasing the P1 generator torque during engine shutdown, thus mitigating the knocking noise. However, even this cannot completely eliminate the knocking noise, which can still be heard to some extent both outside and inside the vehicle. Furthermore, when the battery is fully charged, this problem cannot be improved by increasing the generator torque during engine shutdown, resulting in strong complaints in this scenario.

[0029] Based on this, this application provides a solution that allows for joint control of the engine and / or generator during the shutdown process to address the knocking noise problem caused by the splines connecting the engine and generator. Specifically, when conditions permit, the generator torque and engine throttle are controlled synchronously to optimize spline knocking. Increasing the generator torque is primarily to increase the engine's resistance torque during shutdown, thereby reducing speed fluctuations; controlling the throttle opening reduces the engine's intake air volume during shutdown, thereby reducing piston compression and cylinder pressure, resulting in smoother engine resistance during shutdown and thus reducing engine speed fluctuations.

[0030] It should be noted that the entire control process involves the vehicle controller (HCU) and various sub-controllers, such as the engine management system (EMS) and the power electronics unit (PEU).

[0031] Among them, the HCU is the main controller of the hybrid power system, which is responsible for managing the entire powertrain. Based on the driver's driving intention, the overall vehicle driving status, and the operating status of various vehicle components (including engine, transmission, motor, battery, etc.), it determines the torque distribution of the engine and motor, the opening and closing of high voltage electricity, engine starting or stopping, accessory enabling, and other operations.

[0032] The HCU collects various switch and sensor signals related to vehicle control; it coordinates the control of the EMS, transmission controller, battery management system, and motor controller through command and data interaction via the CAN bus; and it controls accessories such as the starter motor, fan, and water pump through multiple relays. Furthermore, it achieves high energy efficiency through on-the-go charging and regenerative braking.

[0033] The instantaneous charging power limit refers to the maximum charging power that an electric vehicle can accept per unit time during the charging process. The instantaneous charging power will vary depending on the charging method and battery status.

[0034] To facilitate understanding of the technical solution of this application, specific embodiments will be described below.

[0035] See Figure 2 The figure is a flowchart of a vehicle control method provided in an embodiment of this application, as shown below. Figure 2 As shown, the method includes:

[0036] S201: In response to the detection of an engine shutdown command, obtain the instantaneous charging power limit of the battery and the charging power after engine shutdown.

[0037] In this embodiment, after the HCU issues a shutdown command, it acquires the instantaneous charging power limit of the battery and the shutdown charging power. Then, it determines the magnitude of the instantaneous charging power and the shutdown charging power, and uses different control strategies to control the vehicle based on the relationship between the two.

[0038] The process of obtaining the instantaneous charging power of the battery includes: determining the charging power of the battery within a preset time period by querying the battery charging MAP. The preset time period can be determined according to the actual application scenario; for example, a preset time period of 0.5 seconds means obtaining the battery's instantaneous charging power limit for 0.5 seconds.

[0039] The process of obtaining the battery's shutdown charging power includes: after detecting a shutdown command, obtaining the generator's speed and generating torque; and calculating the shutdown charging rate based on the generator's speed and generating torque.

[0040] S202: If the instantaneous charging power limit is less than the charging power when the engine is off, the vehicle is controlled using the first control strategy.

[0041] S203: If the instantaneous charging power limit is not less than the off-fire charging power, the vehicle shall be controlled using the first control strategy and / or the second control strategy.

[0042] In this embodiment, after obtaining the instantaneous charging power limit and the off-fire charging power of the battery, the relationship between the two is determined. If the instantaneous charging power limit is less than the off-fire charging power, it indicates that the battery is currently fully charged and the engine speed fluctuation cannot be reduced by adjusting the generator torque. In this condition, the vehicle is controlled using the first control strategy. The first control strategy is used to control the engine throttle opening.

[0043] In practice, when the HCU determines that the instantaneous charging power limit is less than the shutdown charging power, it can send a control command to the EMS. This control command includes a first control strategy. After receiving the control command, the EMS adjusts the engine throttle opening according to the first control strategy.

[0044] In one implementation, a first control strategy is used to control the vehicle, including: controlling the engine throttle opening to a first angle; and if the engine speed drops to a first speed value, controlling the engine throttle opening to a second angle. The second angle is greater than the first angle. That is, the engine throttle opening is first reduced, and then increased once the engine speed drops to the first speed value. The specific values ​​of the first and second angles can be determined according to the actual application, and are not limited in this embodiment.

[0045] For example, while the EMS controls the fuel cut-off, it also controls the engine throttle opening to quickly decrease to the minimum (<0.3%). When the engine speed drops to 0 rpm, the throttle returns to its initial position (second angle).

[0046] If the instantaneous charging power limit is not less than the charging power when the engine is off, it indicates that the battery is not fully charged. Engine speed fluctuations can be reduced by adjusting the generator torque and / or controlling the throttle opening. In this condition, the vehicle is controlled using the first control strategy and / or the second control strategy. The second control strategy is used to control the generator's generating torque.

[0047] In other words, when the instantaneous charging power limit is not less than the off-fire charging power, the vehicle can be controlled using either the first control strategy or the second control strategy, or the first control strategy and the second control strategy can be used simultaneously to control the vehicle, thereby reducing engine speed fluctuations.

[0048] In practical implementation, when the HCU determines that the instantaneous charging power limit is not less than the shutdown charging power, it can send a first control command to the EMS. This first control command includes a first control strategy. After receiving the control command, the EMS adjusts the engine throttle opening according to the first control strategy. And / or, the HCU sends a second control command to the PEU, which includes a second control strategy. The PEU adjusts the generator torque according to the second control strategy.

[0049] In one implementation, the vehicle is controlled using a second control strategy, including: controlling the generator to increase the generating torque; and if the engine speed drops to a second speed value, controlling the generator to reduce the generating torque.

[0050] Specifically, when controlling the generator to increase its generating torque, the generator can be controlled to increase its torque according to a first slope to a first torque. The first slope and the second torque can be calibrated according to the actual application. For example, the PEU controls the generator to increase its torque at 600 Nm / s (first slope) to reach a set 45 Nm (second torque).

[0051] In one implementation, if the engine speed drops to a second speed value, the generator is controlled to reduce its generating torque to a second torque according to a second slope. The second speed value and the second slope can be calibrated according to the actual application. For example, when the generator speed drops to 100 rpm (the second speed value), the generator torque begins to recover to 0 Nm (the second torque) at a rate of 600 Nm / s (the second slope).

[0052] In this embodiment, after the generator torque is increased to the first torque at a first slope and before the engine speed drops to the second speed value, the generator is controlled to operate at the first torque. That is, the generator is controlled to operate at the first torque for a certain period of time.

[0053] As can be seen, after adopting the above control method, under normal operating conditions, the engine speed fluctuation during shutdown is smaller, smoother, and without knocking characteristics, achieving imperceptible shutdown. In extreme scenarios (battery cannot be charged, extreme cold, forced engine start with a fully charged battery), knocking vibration noise can also be significantly reduced, preventing driver complaints.

[0054] To facilitate understanding of the specific implementation of this application, a specific scenario will be used as an example for illustration.

[0055] After the HCU issues a shutdown command, when the HCU determines that the instantaneous charging power limit of the battery is less than the shutdown charging power, the EMS controls the fuel cut-off and simultaneously controls the engine throttle opening to quickly decrease to the minimum (<0.3%). When the speed drops to 0 rpm, the throttle returns to its initial position.

[0056] When the HCU determines that the instantaneous charging power limit of the battery is greater than or equal to the charging power during engine shutdown, the EMS controls the engine to cut off fuel and simultaneously controls the throttle opening to quickly decrease to the minimum. When the speed drops to 0 rpm, the throttle returns to its initial position. At the same time, the PEU controls the generator to increase the generated torque at an appropriate slope (600 Nm / s) to reach the set target value (45 Nm) and maintain it for a certain period of time. When the generator speed drops to 100 rpm, the generator torque begins to recover to 0 Nm at an appropriate slope (600 Nm / s).

[0057] To better illustrate the effectiveness of the control method provided in this application, see [link to relevant documentation]. Figures 3-6 The test data comparison chart shown is shown.

[0058] When the hybrid vehicle is turned off while stationary or during low-speed driving, noticeable knocking sounds can be heard both outside and inside the vehicle. Test data in this scenario is as follows: Figure 3 As shown, the tapping duration is 1.6 seconds and the tapping vibration reaches 4g.

[0059] After optimizing the shutdown process and increasing the generator's generating torque, the test data are as follows: Figure 4 As shown, there were still two brief knocks, with the maximum knock energy reaching 2.8g.

[0060] When optimizing the shutdown process to increase the generator's output torque and controlling the throttle opening to a minimum, the test data is as follows: Figure 5 As shown in the test, the engine shutdown process was smooth and imperceptible, with no knocking characteristics.

[0061] When encountering extreme scenarios (battery cannot be charged), the test data for the engine shutdown process is as follows: Figure 6 As shown, the maximum impact vibration is about 2g, and the duration is shortened to 0.7 seconds, so that there will be no complaints.

[0062] As can be seen, under normal usage scenarios, by controlling and optimizing the generator torque and engine throttle opening, the engine shutdown process is faster and smoother, with no knocking sounds inside or outside the vehicle. In extreme scenarios, by optimizing the engine throttle opening, there is only a brief and slight knocking sound, improving the user's driving experience.

[0063] Based on the above method embodiments, this application provides a controller and a vehicle, which will be described below in conjunction with specific embodiments.

[0064] See Figure 7 The figure shows a controller provided in an embodiment of this application. The controller 700 includes an acquisition unit 701 and a control unit 702.

[0065] Specifically, the acquisition unit 701 is used to acquire the instantaneous charging power limit and the charging power after the engine is turned off in response to the detection of the engine shutdown command.

[0066] Control unit 702 is used to control the vehicle using a first control strategy if the instantaneous charging power limit is less than the engine shutdown charging power. The first control strategy is used to control the throttle opening of the engine.

[0067] The control unit 702 is further configured to control the vehicle using the first control strategy and / or the second control strategy if the instantaneous charging power limit is not less than the off-fire charging power, wherein the second control strategy is used to control the generator torque.

[0068] In some embodiments, the control unit 702 is specifically used to control the throttle opening of the engine to a first angle; if the engine speed drops to a first speed value, the control unit controls the throttle opening of the engine to a second angle, the second angle being greater than the first angle.

[0069] In some embodiments, the control unit 702 is specifically used to control the generator to increase the generating torque; if the engine speed drops to a second speed value, the generator's generating torque is controlled to decrease.

[0070] In some implementations, the control unit 702 is specifically configured to control the generator to increase the generating torque to a first torque according to a first slope.

[0071] In some embodiments, the control unit 702 is specifically configured to control the generator to reduce the generating torque to a second torque according to a second slope if the engine speed drops to a second speed value.

[0072] In some embodiments, the control unit 702 is further configured to control the generator to operate at the first torque after the generator torque is increased to the first torque at the first slope and before the engine speed drops to the second speed value.

[0073] In some implementations, the acquisition unit 701 is specifically used to determine the instantaneous charging power limit of the battery within a preset time period by querying the battery charging MAP.

[0074] In some implementations, the acquisition unit 701 is specifically used to acquire the generator speed and generating torque after detecting the shutdown command; and to calculate the shutdown charging power based on the generator speed and generating torque.

[0075] It should be noted that the specific implementation of each of the above units can be found in the relevant descriptions in the above method embodiments.

[0076] Based on the above embodiments, this application provides a vehicle 800, which includes a controller 700, a generator 801, and an engine 802.

[0077] The controller 700 is used to control the generator 801 and the engine 802 to realize the control function in the above method embodiment;

[0078] The generator 801 is used to charge the battery of the vehicle and / or supply power to the electrical equipment in the vehicle.

[0079] The engine 802 is used to provide power to the vehicle.

[0080] This application provides a computer-readable storage medium, including instructions or a computer program, which, when run on a computer, causes the computer to perform the vehicle control method described above.

[0081] This application provides a computer program product that, when run on a computer, causes the computer to execute the vehicle control method described above.

[0082] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems or apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant parts can be referred to the method section.

[0083] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0084] It should also 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 a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0085] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0086] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A vehicle control method, characterized in that, The method includes: In response to the detection of an engine shutdown command, the instantaneous charging power limit of the battery and the charging power after engine shutdown are obtained; If the instantaneous charging power limit is less than the engine shutdown charging power, the vehicle is controlled using a first control strategy, which is used to control the throttle opening of the engine. If the instantaneous charging power limit is not less than the off-fire charging power, the vehicle is controlled using the first control strategy and / or the second control strategy, wherein the second control strategy is used to control the generator's generating torque.

2. The method according to claim 1, characterized in that, The vehicle is controlled using a first control strategy, including: The throttle opening of the engine is controlled at the first angle; If the engine speed drops to a first speed value, the throttle opening of the engine is controlled to a second angle, which is greater than the first angle.

3. The method according to claim 1 or 2, characterized in that, The method of controlling the vehicle using the second control strategy includes: Control the generator to increase the generating torque; If the engine speed drops to the second speed value, the generator's power generation torque is reduced.

4. The method according to claim 3, characterized in that, The method of controlling the generator to increase the generating torque includes: Control the generator to increase the generating torque to the first torque according to the first slope.

5. The method according to claim 3, characterized in that, If the engine speed drops to the second speed value, controlling the generator's output torque to decrease includes: If the engine speed drops to the second speed value, the generator is controlled to reduce the generating torque to the second torque according to the second slope.

6. The method according to claim 4, characterized in that, After the generator is controlled to increase its torque to a first torque at a first slope and before the engine speed drops to a second speed value, the method further includes: The generator is controlled to operate at the first torque.

7. The method according to claim 1, characterized in that, The acquisition of the instantaneous charging power limit of the battery includes: By consulting the battery charging MAP, the charging power of the battery within a preset time period is determined as the instantaneous charging power limit.

8. The method according to claim 1, characterized in that, The process of obtaining the battery's power during power-off charging includes: After detecting the shutdown command, the generator speed and generating torque are obtained; The shutdown charging power is calculated based on the generator's rotational speed and the generator's torque.

9. A controller, characterized in that, The controller includes: The acquisition unit is used to acquire the instantaneous charging power limit and the charging power after the engine is turned off in response to the detection of the engine shutdown command. The control unit is used to control the vehicle using a first control strategy if the instantaneous charging power limit is less than the engine shutdown charging power. The first control strategy is used to control the throttle opening of the engine. The control unit is further configured to control the vehicle using the first control strategy and / or the second control strategy if the instantaneous charging power limit is not less than the off-fire charging power, wherein the second control strategy is configured to control the generator torque.

10. A vehicle, characterized in that, The vehicle includes the controller, generator, and engine as described in claim 9; The controller is used to control the generator and the engine; The generator is used to charge the vehicle's battery and / or supply power to electrical equipment in the vehicle; The engine is used to provide power to the vehicle.

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