Engine stop position control method and device, vehicle, storage medium and chip

Abstract

This application provides an engine shutdown piston position control method, device, vehicle, storage medium, and chip. The method includes: an EMS determining whether the engine oil temperature is greater than or equal to a preset oil temperature threshold; if so, the EMS calculates a first torque and uses it as a target torque to control the engine shutdown piston position; if not, the VCU calculates a second torque and uses it as the target torque; and the GCU controls engine shutdown based on the target torque. In this application embodiment, under certain specific conditions, only the VCU or EMS needs to perform torque control during the engine shutdown process, improving the control efficiency of the engine shutdown piston position, simplifying the control logic, reducing the complexity of the VCU software logic, and decreasing the software development and matching workload.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and more specifically to an engine stop position control method, device, vehicle, storage medium, and chip. Background Technology

[0002] Vehicle noise, vibration, and harshness (NVH) performance refers to the subjective feeling a user has of a car under specific operating conditions, such as vibration and rumbling noise. It is a comprehensive performance indicator for measuring the quality of automobile manufacturing and is widely concerned by major international automotive manufacturers and parts suppliers. Statistics show that approximately one-third of vehicle malfunctions are related to NVH issues, and major companies spend nearly 20% of their R&D budget on solving NVH problems.

[0003] In new energy vehicles equipped with engines (such as range-extended electric vehicles, hybrid electric vehicles, and plug-in hybrid electric vehicles), the engine piston position during engine shutdown has a significant impact on NVH performance during the next engine start-up. Therefore, to improve NVH performance during engine start-up, it is necessary to control the engine piston position during engine shutdown.

[0004] In existing technologies, the engine stop piston position is typically controlled by an Engine Management System (EMS), a Vehicle Control Unit (VCU), and a Generator Control Unit (GCU). Specifically, when the VCU receives a stop command, it calculates the pre-controlled torque requirement and sends a valid engine stop flag to the EMS. After receiving the engine stop flag from the VCU, the EMS delays for a period before calculating the engine stop torque requirement and sending the calculated torque along with a valid engine position control flag to the VCU. During this delay, the EMS sends an invalid engine position control flag to the VCU. The VCU determines whether the engine position control flag sent by the EMS is valid. If invalid, it transmits the pre-controlled torque requirement as the target torque to the GCU; if valid, it transmits the engine stop torque requirement as the target torque to the GCU. The GCU uses the obtained target torque to control the motor connected to the engine, thereby controlling the engine stop piston position.

[0005] Understandably, during the aforementioned delay time, the pre-control required torque calculated by the VCU is used as the target torque; after the delay time, the engine shutdown required torque calculated by the EMS is used as the target torque. In other words, both the VCU and EMS need to participate in the torque control during the engine shutdown process. During this process, the pre-control required torque calculated by the VCU and the engine shutdown required torque calculated by the EMS may interfere with each other, resulting in low efficiency in controlling the engine shutdown piston position. Furthermore, in low-temperature environments, due to the high viscosity of the engine oil, the EMS cannot properly calculate the engine shutdown required torque, requiring the VCU to control the entire engine shutdown process. For the VCU, it needs to determine whether the EMS can normally activate the engine shutdown position control function after receiving the shutdown flag, increasing the complexity of the VCU software logic and the workload of software development and matching.

[0006] It should be noted that the information disclosed in the background section of this application is intended only to enhance the understanding of the general background of this application, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0007] In view of this, this application provides an engine shutdown position control method, device, vehicle, storage medium, and chip to solve the problems in the prior art where torque control requires the joint participation of VCU and EMS in the engine shutdown process, resulting in low control efficiency of the engine shutdown piston position; as well as the high complexity of VCU software logic and the large workload of software development matching.

[0008] In a first aspect, embodiments of this application provide a method for controlling the position of an engine stop piston, including:

[0009] EMS determines whether the engine oil temperature is greater than or equal to the preset oil temperature threshold.

[0010] When the EMS determines that the engine oil temperature is greater than or equal to the oil temperature threshold, the EMS calculates a first torque and uses the first torque as the target torque. The first torque is used to control the position of the engine stop piston.

[0011] When the EMS determines that the engine oil temperature is lower than the oil temperature threshold, the VCU calculates the second torque and uses the second torque as the target torque;

[0012] The GCU controls the engine to stop based on the target torque.

[0013] In one possible implementation, the EMS determines whether the engine oil temperature is greater than or equal to a preset oil temperature threshold, including:

[0014] The VCU sends an engine stop flag to the EMS;

[0015] If the EMS determines that the engine stop flag is valid, it then determines whether the engine oil temperature is greater than or equal to the oil temperature threshold.

[0016] In one possible implementation, the EMS calculates a first torque and uses that first torque as the target torque, including:

[0017] The EMS calculates the first torque and transmits the first torque to the VCU;

[0018] The VCU uses the first torque as the target torque.

[0019] One possible implementation also includes:

[0020] When the EMS determines that the engine oil temperature is greater than or equal to the oil temperature threshold, the EMS sends a first engine position control flag bit to the VCU. The first engine position control flag bit is used to instruct the VCU to use the first torque as the target torque.

[0021] When the EMS determines that the engine oil temperature is lower than the oil temperature threshold, the EMS sends a second engine position control flag to the VCU. The second engine position control flag is used to instruct the VCU to use the second torque as the target torque.

[0022] In one possible implementation, the EMS calculates the first torque, including:

[0023] When the number of engine revolutions is less than or equal to a preset engine revolution threshold, the EMS calculates the first component of the first torque according to the first torque calculation strategy.

[0024] When the number of engine revolutions exceeds a preset engine revolution threshold, the EMS calculates the second component of the first torque according to the second torque calculation strategy.

[0025] The number of engine rotations refers to the number of rotations after the engine stops.

[0026] In one possible implementation, the EMS calculates the first component of the first torque according to a first torque calculation strategy, including:

[0027] The initial torque is determined based on the engine speed and the engine oil temperature;

[0028] The correction coefficient for the initial torque is determined based on the number of times the engine fuel is cut off and the gradient of the engine speed decrease.

[0029] Multiply the initial torque by the correction coefficient to obtain the first component of the first torque.

[0030] In one possible implementation, determining the initial torque based on the engine speed and the engine oil temperature includes:

[0031] In the first three-dimensional table, the initial torque corresponding to the engine speed and engine oil temperature is found based on the engine speed and engine oil temperature.

[0032] In one possible implementation, determining the correction coefficient for the initial torque based on the number of engine fuel cut-offs and the engine speed decrease gradient includes:

[0033] In the second three-dimensional table, the correction coefficients corresponding to the number of times the engine fuel cut-off is found based on the engine speed drop gradient.

[0034] In one possible implementation, after the GCU controls the engine to shut down according to the target torque, it further includes:

[0035] Once the engine speed reaches zero, the EMS stops calculating the first torque.

[0036] Secondly, embodiments of this application provide an engine shutdown piston position control device, comprising:

[0037] EMS is used to determine whether the engine oil temperature is greater than or equal to a preset oil temperature threshold. When the EMS determines that the engine oil temperature is greater than or equal to the oil temperature threshold, the EMS calculates a first torque and uses the first torque as the target torque. The first torque is used to control the position of the engine stop piston.

[0038] The VCU is used to calculate a second torque and use the second torque as the target torque when the EMS determines that the engine oil temperature is lower than the oil temperature threshold.

[0039] The GCU is used to control engine shutdown based on the target torque.

[0040] Thirdly, embodiments of this application provide a vehicle, including:

[0041] The engine stop piston position control device described in the second aspect.

[0042] Fourthly, embodiments of this application provide a computer storage medium including computer instructions that, when executed on the vehicle, cause the vehicle to perform the method described in any one of the first aspects.

[0043] Fifthly, embodiments of this application provide a chip, the chip including a processor and a data interface, the processor reading instructions stored in a memory through the data interface to execute the method described in any one of the first aspects.

[0044] In the embodiments of this application, under certain specific conditions, only the VCU or EMS is needed to perform torque control during the engine shutdown process, thereby improving the control efficiency of the piston position during engine shutdown, simplifying the control logic, reducing the complexity of the VCU software logic, and reducing the workload of software development and matching. Attached Figure Description

[0045] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 This is a schematic diagram of an application scenario provided by an embodiment of this application.

[0047] Figure 2 A timing diagram provided for existing technologies.

[0048] Figure 3 This is a flowchart illustrating an engine shutdown piston position control method provided in an embodiment of this application.

[0049] Figure 4 This is a flowchart illustrating another engine shutdown piston position control method provided in an embodiment of this application.

[0050] Figure 5 This is a flowchart illustrating another engine shutdown piston position control method provided in an embodiment of this application.

[0051] Figure 6 This is a flowchart illustrating another engine shutdown piston position control method provided in an embodiment of this application.

[0052] Figure 7 This is a timing diagram provided for an embodiment of this application.

[0053] Figure 8 This is a schematic diagram of the structure of an engine stop piston position control device provided in an embodiment of this application. Detailed Implementation

[0054] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0055] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0056] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0057] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0058] To facilitate understanding, specific application scenarios will be illustrated below.

[0059] See Figure 1 This is a schematic diagram illustrating an application scenario provided by an embodiment of this application. For example... Figure 1 As shown in the diagram, a vehicle is illustrated in this application scenario. This vehicle includes an EMS, a VCU, and a GCU. The EMS can interact with the VCU, and the VCU can interact with the GCU. The EMS is responsible for determining the control conditions for the engine shutdown piston position and calculating the required torque. The EMS can send the calculated required torque to the VCU, which then transmits this required torque as the target torque to the GCU. The GCU controls the engine shutdown based on this target torque. Alternatively, the VCU can also calculate the required torque and transmit it as the target torque to the GCU, which then controls the engine shutdown based on this target torque.

[0060] It should be pointed out that, Figure 1 This is merely an illustrative example of an application scenario involved in the embodiments of this application and should not be construed as limiting the scope of protection of this application. For example, the vehicles involved in the above application scenario can be passenger cars, buses, trucks, etc., and the embodiments of this application do not specifically limit the type of vehicle. Furthermore, it is understood that, in addition to... Figure 1In addition to EMS, VCU and GCU, there are other functional units or modules involved, which will not be described in detail in the embodiments of this application.

[0061] See Figure 2 This is a timing diagram provided for existing technologies. For example... Figure 2 As shown, in the prior art, after the VCU receives the stop command at time t0, the engine stop flag bit sent by the VCU to the EMS changes from an invalid state to an valid state (in this application scenario, a low level represents an invalid state, and a high level represents a valid state). Simultaneously, the VCU begins calculating the pre-control required torque. After the EMS receives the engine stop flag bit sent by the VCU, it needs to delay for a period of time, i.e., from t0 to t1, until time t1, before starting to calculate the engine stop required torque and sending the calculated engine stop required torque and a valid engine position control flag bit (i.e., the engine position control flag bit is at a high level) to the VCU. During the time interval from t0 to t1, the EMS sends an invalid engine position control flag bit to the VCU (i.e., the engine position control flag bit is at a low level). The VCU determines whether the engine position control flag sent by the EMS is valid. If the engine position control flag is invalid, the pre-control required torque is transmitted to the GCU as the target torque for the GCU to execute. If the engine position control flag is valid, the engine shutdown required torque is transmitted to the GCU as the target torque for the GCU to execute. At time t2, the engine speed is zero, and the engine shutdown piston position control function is stopped.

[0062] Understandably, during the time interval t0 to t1, the pre-control required torque calculated by the VCU is used as the target torque; during the time interval t1 to t2, the engine shutdown required torque calculated by the EMS is used as the target torque. In other words, both the VCU and EMS need to participate in the torque control during the engine shutdown process. During this process, the pre-control required torque calculated by the VCU and the engine shutdown required torque calculated by the EMS may interfere with each other, resulting in low efficiency in controlling the engine shutdown piston position. Furthermore, in low-temperature environments, due to the high viscosity of the engine oil, the EMS cannot properly calculate the engine shutdown required torque, requiring the VCU to control the entire engine shutdown process. For the VCU, it needs to determine whether the EMS can normally activate the engine shutdown piston position control function after receiving the shutdown flag, increasing the complexity of the VCU software logic and the workload of software development and matching.

[0063] To address the aforementioned problems, this application provides an engine shutdown piston position control method. Under specific conditions, only the VCU or EMS is needed to control the torque during the engine shutdown process, improving the control efficiency of the engine shutdown piston position. The control logic is simple, reducing the complexity of the VCU software logic and the workload of software development and matching. This will be described in detail below.

[0064] See Figure 3 This is a flowchart illustrating an engine shutdown piston position control method provided in an embodiment of this application. The method can be applied to... Figure 1 The application scenarios shown are as follows: Figure 3 As shown, it mainly includes the following steps.

[0065] Step S301: EMS determines whether the engine oil temperature is greater than or equal to the oil temperature threshold.

[0066] In this embodiment, engine oil has a lubricating function, which is beneficial for EMS to control the engine. However, when the engine oil temperature is too low, the engine oil becomes viscous, similar to jelly, and the EMS cannot control the engine stop piston position. Therefore, an oil temperature threshold can be set, which is a temperature critical point. This critical point is used to determine whether the EMS can control the engine stop piston position.

[0067] Specifically, if the engine oil temperature is greater than or equal to the oil temperature threshold, it means that the EMS can control the engine stop piston position and proceed to step S302; if the engine oil temperature is less than the oil temperature threshold, it means that the EMS cannot control the engine stop piston position and the VCU needs to control the engine to stop, proceed to step S303.

[0068] In one possible implementation, before the EMS determines whether the engine oil temperature is greater than or equal to the oil temperature threshold, the EMS must first receive the engine stop flag bit sent by the VCU. In this embodiment, the engine stop flag bit is a command information sent by the VCU to the EMS, enabling the EMS to perform relevant control on the engine according to the command information. Specifically, the EMS detects the engine stop flag bit sent by the VCU. When the stop flag bit is detected as valid, the EMS performs an oil cut-off operation on the engine; when the stop flag bit is detected as invalid, the EMS does not perform any relevant processing on the engine.

[0069] Step S302: EMS calculates the first torque and uses the first torque as the target torque.

[0070] In this embodiment of the application, when the EMS determines that the engine oil temperature is greater than or equal to the oil temperature threshold, the EMS calculates the first torque, and then controls the engine stop piston position in subsequent steps using the first torque calculated by the EMS, so that the engine piston stops at the specified position.

[0071] In one possible implementation, the EMS calculates a first torque and transmits it to the VCU. The VCU then uses this first torque as the target torque and transmits it to the GCU. In other words, the first torque calculated by the EMS needs to be transmitted to the GCU via the VCU. This is because, in new energy vehicles, when safety is a concern, signal transmission in the EMS must be managed by the VCU, thus preventing direct communication between the GCU and EMS. For example, when the VCU detects an unexpected situation (such as a generator failure), it will promptly terminate the transmission of the target torque to prevent further damage. Of course, in some possible implementations, those skilled in the art can directly transmit the first torque calculated by the EMS to the GCU according to actual needs; this application does not impose specific limitations on this.

[0072] Step S303: The VCU calculates the second torque and uses the second torque as the target torque.

[0073] In this embodiment, when the EMS determines that the engine oil temperature is lower than the oil temperature threshold, it calculates a second torque through the VCU, and then controls the engine to shut down using the second torque calculated by the VCU in subsequent steps. It is worth noting that the engine shutdown controlled by the second torque at this time will no longer control the engine piston position.

[0074] Step S304: The GCU controls the engine to stop based on the target torque.

[0075] In this embodiment, after receiving the target torque from the VCU, the GCU controls the engine to stop based on the target torque. Specifically, the motor is coupled to the engine through a transmission unit, and the motor drives or brakes the engine. The GCU controls the motor based on the target torque, thereby controlling the engine to stop.

[0076] In the embodiments of this application, under certain specific conditions, only the VCU or EMS is needed to perform torque control during the engine shutdown process, thereby improving the control efficiency of the piston position during engine shutdown, simplifying the control logic, reducing the complexity of the VCU software logic, and reducing the workload of software development and matching.

[0077] See Figure 4 This is a flowchart illustrating another engine shutdown piston position control method provided in an embodiment of this application. Figure 4 As shown, the method is in Figure 3The steps shown in step S302 are preceded by the following steps.

[0078] Step S401: The EMS sends the first engine position control flag to the VCU.

[0079] In this embodiment, the EMS can send an engine position control flag to the VCU, and the VCU can determine whether to use the first torque calculated by the EMS as the target torque based on the engine position control flag.

[0080] Specifically, the engine position control flags include a first engine position control flag and a second engine position control flag. The first engine position control flag is used to instruct the VCU to use a first torque as the target torque, and the second engine position control flag is used to instruct the VCU to use a second torque as the target torque. In some possible implementations, the first engine position control flag may also be referred to as a valid engine position control flag; and the second engine position control flag may also be referred to as an invalid engine position control flag.

[0081] In this embodiment of the application, after the EMS sends the first engine position control flag to the VCU, the VCU uses the first torque as the target torque in subsequent steps according to the indication of the first engine position control flag.

[0082] In one possible implementation, when the engine oil temperature is greater than or equal to the oil temperature threshold, as mentioned above, the EMS can perform engine stop piston position control at this time. Therefore, by using the first engine position control flag, the target torque that the GCU ultimately executes can be the first torque.

[0083] In addition, Figure 4 The steps shown in step S303 are preceded by the following steps.

[0084] Step S402: The EMS sends the second engine position control flag to the VCU.

[0085] In this embodiment of the application, after the EMS sends the second engine position control flag to the VCU, the VCU uses the second torque as the target torque in subsequent steps according to the indication of the second engine position control flag.

[0086] In one possible implementation, when the engine oil temperature is lower than the oil temperature threshold, as mentioned above, the EMS cannot perform engine stop piston position control at this time. Therefore, the second engine position control flag is used to make the VCU calculate the second torque, so that the target torque executed by the GCU is the second torque.

[0087] See Figure 5This is a flowchart illustrating another engine shutdown piston position control method provided in an embodiment of this application. Figure 5 As shown, the method is in Figure 4 Based on this, step S302 specifically includes the following steps.

[0088] Step S3021: Whether the number of engine rotations is less than or equal to the preset engine rotation threshold.

[0089] In practical applications, after the fuel supply is cut off, a small amount of residual fuel remains inside the engine, which continues to drive the engine. Therefore, during this process, the EMS (Engine Management System) cannot use traditional algorithms to calculate the required torque for engine shutdown control. This traditional algorithm is the one currently used by EMS to calculate the required torque for engine shutdown; for the sake of brevity, it will not be elaborated upon here.

[0090] In one possible implementation, the number of engine revolutions can be used to characterize the consumption of residual fuel inside the engine. Specifically, after the EMS receives a valid engine stop flag and cuts off the fuel supply, the number of engine revolutions that will continue during the residual fuel consumption process can be used as an engine revolutions threshold.

[0091] In one possible implementation, since the existing EMS method for calculating the torque required for the engine stop piston position needs to be executed after the fuel is exhausted, in order to solve this technical problem, in this embodiment of the application, when the number of engine rotations is less than or equal to a preset engine rotation threshold, step S3022 is executed; when the number of engine rotations is greater than the preset engine rotation threshold, step S3023 is executed.

[0092] Step S3022: The EMS calculates the first component of the first torque according to the first torque calculation strategy.

[0093] Since existing technologies cannot use EMS to calculate the engine stop piston position required torque when it is less than the engine revolution threshold, the present invention provides a calculation method for it. This calculation method is a first torque calculation strategy, wherein the engine stop piston position required torque calculated according to the first torque calculation strategy is the first component of the first torque.

[0094] In this embodiment, the first torque calculation strategy is specifically expressed as follows:

[0095] The first component of the first torque = initial torque * correction factor;

[0096] Since there is a mapping relationship between engine speed and engine oil temperature and initial torque, the initial torque can be determined based on engine speed and engine oil temperature. There is also a mapping relationship between the number of engine fuel cut-offs and the engine speed drop gradient and correction coefficient, so the correction coefficient for the initial torque can be determined based on the number of engine fuel cut-offs and the engine speed drop gradient.

[0097] In one possible implementation, the torque can be determined using a three-dimensional table. Specifically, in this embodiment, a first three-dimensional table is defined to record engine speed, engine oil temperature, and the corresponding initial torque, and stored in the EMS. A second three-dimensional table is defined to record the number of engine fuel cut-offs, the engine speed decrease gradient, and the corresponding correction coefficients, and stored in the EMS. When the EMS needs to calculate the first component of the first torque, the initial torque corresponding to the engine speed and engine oil temperature is found in the first three-dimensional table. In the second three-dimensional table, the initial torque is obtained by multiplying the obtained initial torque by the correction coefficients corresponding to the number of engine fuel cut-offs and the engine speed decrease gradient.

[0098] It is worth noting that the engine speed, engine oil temperature, number of times the engine fuel cut-off occurs, and the engine speed drop gradient mentioned above can be obtained through simple sensor devices and calculations, which will not be elaborated further.

[0099] Step S3023: The EMS calculates the second component of the first torque according to the second torque calculation strategy.

[0100] In this embodiment, when the engine's residual fuel is exhausted, the required torque to control the engine stop piston position is the second component of the first torque. In this document, its calculation method is defined as the second torque calculation strategy, which is the same as the engine position control torque calculation method of EMS in the prior art, and will not be described in detail here.

[0101] Step S3024: Use the first torque as the target torque.

[0102] For specific details regarding the implementation examples in this application, please refer to the above. Figure 3 and Figure 4 The descriptions in the illustrated embodiments are omitted for brevity.

[0103] See Figure 6 This is a flowchart illustrating another engine shutdown piston position control method provided in an embodiment of this application. Figure 6 As shown, the method is in Figure 5Following step S304, the specific steps include the following steps.

[0104] Step S601: After the engine speed reaches zero, the EMS stops calculating the first torque.

[0105] As mentioned above, when the engine oil temperature is greater than or equal to the oil temperature threshold, the engine is stopped by the first torque calculated by the EMS, causing the engine piston to stop at a designated position. When the engine speed reaches zero, it indicates that the engine piston has stopped at the designated position. At this point, the EMS can stop calculating the first torque to save system power consumption.

[0106] Similarly, when the engine oil temperature is lower than the oil temperature threshold, the engine is stopped by the second torque calculated by the VCU. When the engine speed is zero, it means that the engine has stopped running. At this time, the VCU can stop calculating the second torque to save system power consumption.

[0107] See Figure 7 This is a timing diagram provided in an embodiment of this application. Figure 7 As shown, this timing diagram includes the distribution curves of engine speed, GCU actuated torque, first torque, engine stop flag, and engine position control flag when the engine stop piston position is controlled according to the above method. Its working principle will be explained in detail below.

[0108] exist Figure 7 At time t0, as shown, after the VCU receives the stop command, the engine stop flag sent by the VCU to the EMS changes from an invalid state to an active state. The EMS first checks if the engine oil temperature is greater than or equal to the oil temperature threshold. When the engine oil temperature is greater than or equal to the oil temperature threshold, the engine position control flag sent by the EMS to the VCU changes from an invalid state to an active state. At this time, the number of engine revolutions must be less than or equal to the engine revolutions threshold (the number of engine revolutions is calculated from t0). Therefore, the EMS starts calculating the first component of the first torque, delaying for a period of time until the number of engine revolutions exceeds the engine revolutions threshold. Figure 7 At time t2, as shown, the EMS begins calculating the second component of the first torque, delaying the process until the engine speed reaches zero and the engine stops and the piston is in the appropriate position. This is the point at which the EMS calculates the second component of the first torque. Figure 7The figure shows time t3. It can be understood that during the time interval t0 to t1, the VCU receives the first component of the first torque calculated by the EMS and transmits this first component of the first torque to the GCU as the GCU execution torque to control the position of the engine stop piston; during the time interval t1 to t2, the VCU receives the second component of the first torque calculated by the EMS and transmits this second component of the first torque to the GCU as the GCU execution torque to control the position of the engine stop piston.

[0109] When the engine oil temperature is lower than the oil temperature threshold, the EMS sends an invalid engine position control flag to the VCU. At this time, the VCU calculates the second torque and transmits it as the target torque to the GCU as the GCU execution torque to control the engine to stop.

[0110] See Figure 8 This is a schematic diagram of the structure of an engine shutdown piston position control device provided in an embodiment of this application. Figure 8 As shown, it mainly includes the following modules.

[0111] EMS is used to determine whether the engine oil temperature is greater than or equal to a preset oil temperature threshold. When EMS determines that the engine oil temperature is greater than or equal to the oil temperature threshold, EMS calculates a first torque and uses the first torque as the target torque. The first torque is used to control the position of the engine shutdown piston. VCU is used to calculate a second torque when EMS determines that the engine oil temperature is less than the oil temperature threshold, and uses the second torque as the target torque. GC is used to control the engine shutdown according to the target torque.

[0112] For details regarding the specific content involved in the embodiments of this application, please refer to the description of the above method embodiments. For the sake of brevity, these details will not be repeated here.

[0113] Corresponding to the above embodiments, this application also provides a vehicle that includes the engine stop piston position control device described in the above embodiments. For details regarding this embodiment, please refer to the description of the above device embodiments; for the sake of brevity, further elaboration will not be repeated here.

[0114] Corresponding to the above embodiments, this application also provides a computer-readable storage medium, wherein the computer-readable storage medium may store a program, wherein when the program runs, it can control the device where the computer-readable storage medium is located to execute some or all of the steps in the above method embodiments. Specifically, the computer-readable storage medium may be a magnetic disk, an optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0115] Corresponding to the above embodiments, this application also provides a chip, wherein the chip includes a processor and a data interface, and the processor reads instructions stored in the memory through the data interface to execute some or all of the steps in the above method embodiments.

[0116] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, the simultaneous existence of A and B, or the existence of B alone. 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 of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, and c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0117] Those skilled in the art will recognize that the units and algorithm steps described in the embodiments disclosed herein can be implemented using electronic hardware, computer software, or a combination of electronic hardware and software. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0118] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0119] In the several embodiments provided in this application, any function, if implemented as a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0120] The above description is merely a specific embodiment of this application. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application. The protection scope of this application should be determined by the protection scope of the claims.

Claims

1. An engine stop piston position control method characterized by, include: The Engine Management System (EMS) determines whether the engine oil temperature is greater than or equal to a preset oil temperature threshold. When the EMS determines that the engine oil temperature is greater than or equal to the oil temperature threshold, the EMS calculates a first torque and uses the first torque as the target torque. The first torque is used to control the position of the engine stop piston. When the EMS determines that the engine oil temperature is lower than the oil temperature threshold, the vehicle control unit (VCU) calculates the second torque and uses the second torque as the target torque. The generator control unit (GCU) controls the engine to stop based on the target torque. The EMS determines whether the engine oil temperature is greater than or equal to a preset oil temperature threshold, including: The VCU sends an engine stop flag to the EMS; If the EMS determines that the engine stop flag is valid, it then determines whether the engine oil temperature is greater than or equal to the oil temperature threshold. The EMS calculates the first torque, including: When the number of engine revolutions is less than or equal to a preset engine revolution threshold, the EMS calculates the first component of the first torque according to the first torque calculation strategy. When the number of engine revolutions exceeds a preset engine revolution threshold, the EMS calculates the second component of the first torque according to the second torque calculation strategy. Wherein, the number of engine rotations is the number of rotations after receiving the engine stop flag; The EMS calculates the first component of the first torque according to the first torque calculation strategy, including: The initial torque is determined based on the engine speed and the engine oil temperature; The correction coefficient for the initial torque is determined based on the number of times the engine fuel is cut off and the gradient of the engine speed decrease. Multiply the initial torque by the correction coefficient to obtain the first component of the first torque.

2. The engine stop piston position control method according to claim 1, characterized by, The EMS calculates the first torque and uses the first torque as the target torque, including: The EMS calculates the first torque and transmits the first torque to the VCU; The VCU uses the first torque as the target torque.

3. The engine stop piston position control method according to claim 2, characterized by, Also includes: When the EMS determines that the engine oil temperature is greater than or equal to the oil temperature threshold, the EMS sends a first engine position control flag bit to the VCU. The first engine position control flag bit is used to instruct the VCU to use the first torque as the target torque. When the EMS determines that the engine oil temperature is lower than the oil temperature threshold, the EMS sends a second engine position control flag to the VCU. The second engine position control flag is used to instruct the VCU to use the second torque as the target torque.

4. The engine stop piston position control method according to claim 1, characterized by, Determining the initial torque based on engine speed and engine oil temperature includes: In the first three-dimensional table, the initial torque corresponding to the engine speed and engine oil temperature is found based on the engine speed and engine oil temperature.

5. The engine stop piston position control method according to claim 1, characterized in that, The step of determining the correction coefficient for the initial torque based on the number of engine fuel cut-offs and the engine speed decrease gradient includes: In the second three-dimensional table, the correction coefficients corresponding to the number of times the engine fuel cut-off is found based on the engine speed drop gradient.

6. The engine stop piston position control method according to claim 1, characterized in that, After the GCU controls the engine to stop based on the target torque, it further includes: Once the engine speed reaches zero, the EMS stops calculating the first torque.

7. An engine stop piston position control device, characterized in that, include: EMS is used to determine whether the engine oil temperature is greater than or equal to the preset oil temperature threshold. When the EMS determines that the engine oil temperature is greater than or equal to the oil temperature threshold, the EMS calculates a first torque and uses the first torque as the target torque. The first torque is used to control the position of the engine stop piston. The VCU is used to calculate a second torque and use the second torque as the target torque when the EMS determines that the engine oil temperature is lower than the oil temperature threshold. GCU is used to control engine shutdown based on the target torque; The EMS determines whether the engine oil temperature is greater than or equal to a preset oil temperature threshold, including: The VCU sends an engine stop flag to the EMS; If the EMS determines that the engine stop flag is valid, it then determines whether the engine oil temperature is greater than or equal to the oil temperature threshold. The EMS calculates the first torque, including: When the number of engine revolutions is less than or equal to a preset engine revolution threshold, the EMS calculates the first component of the first torque according to the first torque calculation strategy. When the number of engine revolutions exceeds a preset engine revolution threshold, the EMS calculates the second component of the first torque according to the second torque calculation strategy. Wherein, the number of engine rotations is the number of rotations after receiving the engine stop flag; The EMS calculates the first component of the first torque according to the first torque calculation strategy, including: The initial torque is determined based on the engine speed and the engine oil temperature; The correction coefficient for the initial torque is determined based on the number of times the engine fuel is cut off and the gradient of the engine speed decrease. Multiply the initial torque by the correction coefficient to obtain the first component of the first torque.

8. A vehicle, characterized in that, include: The engine stop piston position control device according to claim 7.

9. A computer storage medium, characterized in that, Includes computer instructions that, when executed on the vehicle, cause the vehicle to perform the method as described in any one of claims 1 to 6.

10. A chip, characterized in that, The chip includes a processor and a data interface. The processor reads instructions stored in the memory through the data interface to execute the method as described in any one of claims 1 to 6.

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