Engine shutdown method, device and equipment and storage medium

Abstract

The invention provides an engine shutdown method, device and equipment and a storage medium, the engine rotating speed is controlled to reach the shutdown target rotating speed in a closed-loop mode based on an integrated starter generator ISG, the engine torque is adjusted to be the target torque, and the engine after torque unloading is obtained; calculating a feed-forward torque according to the target shutdown rotation speed and an expected change rate of the target shutdown rotation speed; and based on the feedforward torque, the rotating speed of the engine after torque unloading is reduced to zero from the shutdown target rotating speed. In the application, the torque of the engine is unloaded based on the ISG, and the rotating speed of the engine after the torque is unloaded is controlled to be reduced to zero according to the expected change rate of the rotating speed based on the feed-forward torque, so that the jittering of the engine in the shutdown process can be effectively relieved, and the driving experience feeling of a user is further improved.

Description

Technical Field

[0001] This application relates to the technical field of vehicle control, and particularly to an engine shutdown method, device, equipment, and storage medium. Background Art

[0002] With the development of new energy technologies, hybrid vehicles have received increasing attention due to their energy-saving and low-emission characteristics.

[0003] The basic configuration of current hybrid vehicles can be a combination of a dual-motor and an engine. During the engine shutdown process, it is impossible to rely on a clutch to decouple the engine from the motor, and the engine itself needs to be controlled to complete the shutdown.

[0004] However, during the process of relying on the engine's own control to complete the shutdown, when the engine speed drops rapidly, affected by the engine's pumping resistance, the torque at the wheel end may change significantly, resulting in increased vibration during the engine shutdown process and reducing the user's driving experience. Summary of the Invention

[0005] An engine shutdown method, device, equipment, and storage medium provided by this application aim to improve the user's driving experience.

[0006] To achieve the above objective, this application adopts the following technical solutions:

[0007] First aspect: This application provides an engine shutdown method, including:

[0008] Based on an integrated starter generator (ISG), the engine speed is controlled in a closed loop to the shutdown target speed, and the torque of the engine is adjusted to the target torque to obtain an engine with torque removed, where the torque of the engine matches the negative torque corresponding to the ISG;

[0009] Calculate the feedforward torque according to the shutdown target speed and the expected change rate of the shutdown target speed;

[0010] Based on the feedforward torque, the speed of the engine with torque removed is reduced from the shutdown target speed to zero.

[0011] In a possible implementation, the calculating the feedforward torque according to the shutdown target speed and the expected change rate of the shutdown target speed includes:

[0012] Calculate the initial feedforward torque according to the shutdown target speed and the expected change rate of the shutdown target speed;

[0013] According to the difference between the expected rotation speed of the engine after torque unloading and the shutdown target rotation speed, the initial feed-forward torque is corrected to obtain the feed-forward torque.

[0014] In a possible implementation, the calculating the feedforward torque according to the shutdown target speed and the expected change rate of the shutdown target speed includes:

[0015] Calculating a feedforward torque according to the shutdown target speed, the expected rate of change of the shutdown target speed, and the expected rate of change of the phase angle of the engine after torque unloading;

[0016] The step of reducing the speed of the engine after torque relief from the shutdown target speed to zero based on the feedforward torque includes:

[0017] Based on the feed-forward torque, the speed of the engine after torque relief is reduced from the shutdown target speed to zero, and the phase angle of the engine after torque relief in a shutdown state is controlled within a preset range.

[0018] In a possible implementation, after calculating the feedforward torque according to the shutdown target speed, the expected change rate of the shutdown target speed, and the expected change rate of the phase angle of the engine after torque unloading, the method further includes:

[0019] Correcting the feed-forward torque to obtain a corrected feed-forward torque;

[0020] Based on the feedforward torque, the speed of the engine after torque relief is reduced from the shutdown target speed to zero, and the phase angle of the engine after torque relief is controlled within a preset range when the engine is in a shutdown state, including:

[0021] Based on the corrected feed-forward torque, the speed of the engine after torque relief is reduced from the shutdown target speed to zero, and the phase angle of the engine after torque relief in the shutdown state is controlled within a preset range.

[0022] In a possible implementation, after reducing the speed of the torque-relieved engine from the shutdown target speed to zero based on the feedforward torque, the method further includes:

[0023] The phase angle when the rotation speed of the engine after torque relief drops to zero is adjusted so that the difference between the phase angle when the rotation speed of the engine after torque relief drops to zero and the expected phase angle is less than or equal to a threshold value.

[0024] In a possible implementation, the integrated starter generator (ISG) is used to control the speed of the engine in a closed loop to a shutdown target speed, adjust the torque of the engine to a target torque, obtain a torque-removed engine, and match the torque of the engine with the negative torque corresponding to the ISG, including:

[0025] Adjusting the speed of the engine to obtain an adjusted engine, wherein the torque of the adjusted engine matches the negative torque corresponding to the ISG;

[0026] Based on the ISG, the speed of the adjusted engine is controlled in a closed loop to reach the shutdown target speed, and the torque of the adjusted engine is adjusted to the target torque to obtain a torque-relieved engine.

[0027] In a possible implementation, the integrated starter generator (ISG) is used to control the engine speed in a closed loop to a shutdown target speed, adjust the engine torque to a target torque, and obtain a torque-relieved engine, including:

[0028] Based on the integrated starter generator ISG, the speed of the engine is controlled in a closed loop to reach the shutdown target speed, and the torque of the engine is adjusted to the target torque according to a preset slope to obtain a torque-relieved engine.

[0029] Second aspect: The present application provides an engine shutdown device, comprising:

[0030] Torque relief unit, calculation unit, and speed reduction unit;

[0031] The torque unloading unit is used to control the engine speed to a shutdown target speed in a closed loop based on an integrated starter generator (ISG), adjust the engine torque to a target torque, and obtain a torque-unloaded engine, wherein the engine torque matches the negative torque corresponding to the ISG;

[0032] The calculation unit is used to calculate the feedforward torque according to the shutdown target speed and the expected change rate of the shutdown target speed;

[0033] The speed reduction unit is used to reduce the speed of the engine after torque relief from the shutdown target speed to zero based on the feedforward torque.

[0034] In a possible implementation, the computing unit includes:

[0035] A calculation subunit and a correction subunit;

[0036] The calculation subunit is used to calculate the initial feed-forward torque according to the shutdown target speed and the expected change rate of the shutdown target speed;

[0037] The correction subunit is used to correct the initial feedforward torque according to the difference between the expected speed of the engine after torque unloading and the shutdown target speed to obtain the feedforward torque.

[0038] In a possible implementation, the calculation unit is specifically used to: calculate the feedforward torque according to the shutdown target speed, the expected change rate of the shutdown target speed, and the expected change rate of the phase angle of the engine after torque unloading;

[0039] The deceleration unit is specifically used to: based on the feedforward torque, reduce the speed of the engine after torque relief from the shutdown target speed to zero, and control the phase angle of the engine after torque relief in the shutdown state within a preset range.

[0040] In a possible implementation, the device further includes: a correction unit;

[0041] The correction unit is used to correct the feed-forward torque to obtain a corrected feed-forward torque;

[0042] The deceleration unit is specifically used to: based on the corrected feed-forward torque, reduce the speed of the engine after torque relief from the shutdown target speed to zero, and control the phase angle of the engine after torque relief in the shutdown state within a preset range.

[0043] In a possible implementation, the device further includes: an adjustment unit;

[0044] The regulating unit is used to adjust the phase angle when the speed of the engine after torque unloading drops to zero, so that the difference between the phase angle when the speed of the engine after torque unloading drops to zero and the expected phase angle is less than or equal to a threshold.

[0045] In a possible implementation, the torque relief unit includes: a speed regulating subunit and a torque relief subunit;

[0046] The speed regulating subunit is used to regulate the speed of the engine to obtain a regulated engine, wherein the torque of the regulated engine matches the negative torque corresponding to the ISG;

[0047] The torque unloading subunit is used to control the speed of the adjusted engine to a shutdown target speed in a closed loop based on the ISG, adjust the torque of the adjusted engine to a target torque, and obtain a torque-unloaded engine.

[0048] In a possible implementation, the torque unloading unit is specifically used to: based on the integrated starter generator ISG, control the engine speed in a closed loop to a shutdown target speed, adjust the engine torque to a target torque according to a preset slope, and obtain a torque-unloaded engine.

[0049] A third aspect: The present application provides a computer device, the computer device comprising: a processor and a memory;

[0050] The memory is used to store program code and transmit the program code to the processor;

[0051] The processor is used to execute the steps of the engine shutdown method as described above according to the instructions in the program code.

[0052] Fourth aspect: The present application provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of an engine shutdown method as described above are implemented.

[0053] Compared with the prior art, this application has the following beneficial effects:

[0054] The present application provides an engine shutdown method, device, equipment and storage medium, which controls the engine speed to a shutdown target speed in a closed loop based on an integrated starter generator (ISG), adjusts the engine torque to a target torque, obtains a torque-relieved engine, and matches the negative torque corresponding to the ISG; calculates a feedforward torque based on the shutdown target speed and the expected rate of change of the shutdown target speed; based on the feedforward torque, reduces the speed of the torque-relieved engine from the shutdown target speed to zero. In the present application, the engine is torque-relieved based on the ISG, and based on the feedforward torque, the speed of the torque-relieved engine is controlled to drop to zero according to the expected rate of change of the speed, which can effectively alleviate the vibration of the engine during the shutdown process, thereby improving the user's driving experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 A flow chart of an engine shutdown method provided in an embodiment of the present application;

[0056] Figure 2 A schematic diagram of the change of the first engine speed and phase angle provided in the embodiment of the present application;

[0057] Figure 3 A schematic diagram of the change of the second engine speed and phase angle provided in an embodiment of the present application;

[0058] Figure 4 A schematic diagram of the change of the third engine speed and phase angle provided in the embodiment of the present application;

[0059] Figure 5 A structural schematic diagram of an engine shutdown device is provided for an embodiment of the present application. DETAILED DESCRIPTION

[0060] The terms "first", "second", "third", etc. in the specification, claims and drawings of this application are used to distinguish different objects rather than to limit a specific order.

[0061] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0062] The basic configuration of current hybrid vehicles can be a combination of dual motors and an engine. During the engine shutdown process, the decoupling between the engine and the motor cannot be achieved by relying on the clutch, and the shutdown needs to be completed by relying on the engine's own control.

[0063] However, in the process of relying on the engine's own control to complete the shutdown, when the engine speed drops rapidly, the torque at the wheel end may change significantly due to the influence of the engine pumping resistance, resulting in increased vibration during the engine shutdown process and reducing the user's driving experience.

[0064] Based on this, the present application provides an engine shutdown method, device, equipment and storage medium, which controls the engine speed to the shutdown target speed in a closed loop based on an integrated starter generator ISG, adjusts the engine torque to the target torque, and obtains the engine after torque relief; calculates the feedforward torque according to the shutdown target speed and the expected change rate of the shutdown target speed; based on the feedforward torque, reduces the speed of the engine after torque relief from the shutdown target speed to zero. In the present application, the engine is torque-relieved based on ISG, and based on the feedforward torque, the speed of the engine after torque relief is controlled to drop to zero according to the expected change rate of the speed, which can effectively alleviate the vibration of the engine during the shutdown process, thereby improving the user's driving experience.

[0065] At the same time, due to the different phase angles of the engine shaft, the corresponding resistance when the engine restarts is different. In this application, when the engine is stopped, the phase angle of the engine is controlled to reduce the resistance when the engine restarts, improve the success rate of the engine restart, reduce the jitter when the engine starts, and enhance the user's driving experience.

[0066] An engine shutdown method provided by the present application is introduced below.

[0067] like Figure 1 As shown, this figure is a flow chart of an engine shutdown method provided in an embodiment of the present application. An engine shutdown method provided in the present application includes S101-S103.

[0068] S101, based on the integrated starter generator ISG, the speed of the engine is controlled in a closed loop to a shutdown target speed, the torque of the engine is adjusted to a target torque, and a torque-relieved engine is obtained.

[0069] Torque is the force that causes an object to rotate. The torque of an engine refers to the torque output from the crankshaft end of the engine.

[0070] In the present application, the torque of the engine matches the negative torque corresponding to the ISG. The torque of the engine can represent the magnitude of the force between the shaft of the engine and the shaft of the motor.

[0071] In the present application, the engine speed can be controlled in a closed loop to the shutdown target speed based on the ISG capability, and the engine torque can be adjusted to the target torque. The target torque is the minimum torque that the engine can provide. Exemplarily, the torque between the engine shaft and the motor shaft is 150N·m, and the negative torque corresponding to the ISG matched therewith can be -150N·m. Based on the negative torque capability of the ISG corresponding to the torque of -150N·m, the torque of 150N·m between the engine shaft and the motor shaft can be unloaded to the target torque corresponding to the engine.

[0072] In a possible implementation, the torque of the engine may be adjusted to a target torque according to a preset slope to obtain a torque-relieved engine.

[0073] For example, when the torque of the engine is 200 N·m, the torque is reduced from 200 N·m to 150 N·m, and then from 150 N·m to 50 N·m, until it reaches the target torque corresponding to the engine. It should be noted that the above is only an example, and the value of the preset slope is not specifically limited in this application.

[0074] In a possible implementation, the above S101 can be implemented in the following manner: that is, by adjusting the speed of the engine to obtain an adjusted engine, the speed of the adjusted engine is controlled to a shutdown target speed in a closed loop based on the ISG, and the torque of the adjusted engine is adjusted to a target torque to obtain a torque-relieved engine.

[0075] The adjusted engine torque matches the negative torque corresponding to the ISG. When the initial engine speed is high, the engine speed can be adjusted first, and the adjusted engine torque can represent the magnitude of the force between the adjusted engine shaft and the motor shaft.

[0076] Specifically, if the negative torque capacity of the ISG cannot balance the torque of the engine, the engine speed can be adjusted to match the adjusted engine torque with the negative torque corresponding to the ISG so that the two are in a balanced state to complete the torque unloading process.

[0077] For example, the torque between the shaft of the regulated engine and the shaft of the motor is 150N·m, and the negative torque corresponding to the ISG is only -50N·m. Since the negative torque corresponding to the ISG is usually fixed, and the negative torque corresponding to the ISG is -50N·m, it is impossible to balance the torque of the regulated engine with a torque of 150N·m. In this case, the engine speed can be adjusted to the shutdown target speed by relying on the control of the engine itself, so that the engine torque is reduced to 50N·m to match the negative torque corresponding to the ISG.

[0078] The torque of the adjusted engine matches the negative torque corresponding to the ISG, that is, based on the negative torque capacity of the ISG corresponding to the torque of -50N·m, the torque of 50N·m between the shaft of the adjusted engine and the shaft of the motor can be unloaded to the target torque corresponding to the engine.

[0079] At the same time, in this process, although it relies on the engine's own control ability to reduce the engine's torque to a certain extent, it does not reduce the engine's torque to a minimum, but only reduces it to a torque that matches the negative torque corresponding to the ISG, which in turn has little effect on the vibration of the entire vehicle.

[0080] S102: Calculate a feedforward torque according to the shutdown target speed and an expected change rate of the shutdown target speed.

[0081] After the engine torque is unloaded to the target torque based on the negative torque capacity of the ISG, the feedforward torque can be calculated according to the shutdown target speed corresponding to the unloaded engine and the expected change rate of the shutdown target speed. The feedforward torque is used to control the torque output of the ISG so that the shutdown target speed can be reduced to the shutdown according to the expected change rate of the shutdown target speed.

[0082] For example, the profile control method can be used to calculate the feedforward torque. That is, the target speed change curve is designed according to the theoretical target speed and the actual engine speed. After obtaining the target speed change curve, the expected change rate of the shutdown target speed can be obtained from the target speed change curve, and the feedforward torque can be calculated from the expected change rate of the shutdown target speed.

[0083] In a possible implementation manner, S102 may be implemented through the following steps.

[0084] The initial feedforward torque is calculated according to the shutdown target speed and the expected change rate of the shutdown target speed, and the initial feedforward torque is corrected according to the difference between the expected speed of the engine after torque unloading and the shutdown target speed to obtain the feedforward torque.

[0085] For example, the profile control method can be used to calculate the initial feedforward torque, which can be used to control the torque output of the ISG so that the shutdown target speed corresponding to the engine after torque relief can drop to the shutdown state according to the expected change rate of the shutdown target speed.

[0086] However, due to the influence of various factors, there may be a certain error between the expected speed of the engine after torque relief and the actual speed of the engine after torque relief. In order to improve the accuracy of controlling the engine shutdown process, in this application, after obtaining the initial feedforward torque, according to the difference between the expected speed of the engine after torque relief and the shutdown target speed corresponding to the engine after torque relief, the proportional-integral-derivative (PID) compensation torque can be calculated, and based on the PID compensation torque, the initial feedforward torque is corrected to obtain the feedforward torque. Then, the feedforward torque can be continued to more accurately control the engine speed to drop to the shutdown according to the expected change rate of the shutdown target speed.

[0087] S103: Based on the feed-forward torque, the rotation speed of the engine after torque relief is reduced from the shutdown target rotation speed to zero.

[0088] After the feed-forward torque is calculated, the speed of the engine after torque relief can be reduced from the shutdown target speed to zero according to the expected change rate of the shutdown target speed drop based on the feed-forward torque.

[0089] To summarize, in this application, the engine is unloaded based on ISG, and based on the feedforward torque, the speed of the engine after torque unloading is controlled to drop to zero according to the expected rate of change of the shutdown target speed, which can effectively alleviate the vibration generated by the engine during the shutdown process, thereby improving the user's driving experience.

[0090] In one possible implementation, the feedforward torque is calculated based on the shutdown target speed and the expected change rate of the shutdown target speed, including: calculating the feedforward torque based on the shutdown target speed, the expected change rate of the shutdown target speed, and the expected change rate of the phase angle of the engine after torque unloading.

[0091] The method of reducing the speed of the engine after torque unloading from the shutdown target speed to zero based on the feedforward torque includes: reducing the speed of the engine after torque unloading from the shutdown target speed to zero based on the feedforward torque, and controlling the phase angle of the engine after torque unloading when it is in a shutdown state within a preset range.

[0092] In an embodiment of the present application, when calculating the feed-forward torque, the speed of the engine after torque unloading, that is, the shutdown target speed, the expected rate of change of the shutdown target speed, and the expected rate of change of the phase angle of the engine after torque unloading are taken into consideration, so that the engine speed and phase angle can be synchronously controlled during the process of controlling the engine shutdown after torque unloading.

[0093] like Figure 2 As described, the figure is a schematic diagram of the change of the first engine speed and phase angle provided by the embodiment of the present application. In the figure, curve 1001 is the expected change curve of the phase angle, curve 1002 is the expected change curve of the shutdown target speed of the engine after torque unloading, and dotted line 1003 is the change curve of the ISG torque. As shown in the figure, due to the delayed torque response of the ISG, when the speed of the engine drops to zero after torque unloading, the torque of the ISG cannot drop to zero quickly, causing the engine to reverse.

[0094] Due to the different phase angles of the engine shaft, the corresponding resistance when the engine restarts is different. In this application, the phase angle and speed of the engine are synchronously controlled when the engine is shut down. While alleviating the vibration generated by the engine during the shutdown process, thereby improving the user's driving experience, by synchronously controlling the phase angle of the engine, the resistance when the engine restarts is smaller, the success rate of the engine restart is increased, the vibration when the engine starts is reduced, and the user's driving experience is further improved.

[0095] At the same time, since the embodiment of the present application adopts a method of synchronously controlling the speed and phase angle of the engine, the engine downtime can be effectively saved.

[0096] In a possible implementation, in order to reduce the influence of the delay of the ISG torque response during the synchronous control of the engine speed and phase angle, after the feedforward torque is calculated according to the shutdown target speed, the expected change rate of the shutdown target speed, and the expected change rate of the phase angle of the engine after the torque is unloaded, the feedforward torque can be corrected to obtain the corrected feedforward torque. Based on the corrected feedforward torque, the speed of the engine after the torque is unloaded is reduced from the shutdown target speed to zero, and the phase angle of the engine after the torque is unloaded is controlled within a preset range when it is in the shutdown state.

[0097] Specifically, Figure 3 As described, the figure is a schematic diagram of the change of the second engine speed and phase angle provided by the embodiment of the present application. In the figure, curve 1011 is the expected change curve of the phase angle, curve 1012 is the expected change curve of the shutdown target speed of the engine after torque removal, and dotted line 1013 is the change curve of the ISG torque. When the engine shutdown process and the phase angle control are carried out simultaneously, the engine speed is controlled by the ISG torque, wherein the ISG motor torque transitions to zero at a fixed preset slope.

[0098] In the present application, the feed-forward torque is corrected, and based on the corrected feed-forward torque, the speed of the engine after the torque is unloaded is reduced to zero, and the phase angle of the engine when it is in a stopped state is controlled within a preset range. While effectively saving the downtime of the engine, the impact caused by the delay of the ISG torque response is reduced to a certain extent.

[0099] In a possible implementation, in order to improve the control accuracy of the phase angle, after the speed of the engine after torque relief is reduced from the shutdown target speed to zero based on the feedforward torque, the phase angle when the speed of the engine after torque relief is reduced to zero is adjusted, so that the difference between the phase angle when the speed of the engine after torque relief is reduced to zero and the expected phase angle is less than or equal to a threshold. Exemplarily, the threshold may be less than or equal to 12°.

[0100] like Figure 4 As shown, this figure is a schematic diagram of the change of the third engine speed and phase angle provided by the embodiment of the present application. In the figure, curve 1021 is the expected change curve of the phase angle, curve 1022 is the expected change curve of the shutdown target speed of the engine after torque removal, and dotted line 1023 is the change curve of the ISG torque.

[0101] In the embodiment of the present application, after the speed of the engine after torque relief drops to zero, the phase angle of the engine is controlled. Specifically, after the engine after torque relief stops, the torque of the ISG is controlled in stages. When the engine is not pulled up, the ISG provides a large fixed torque until the engine has a tendency to be pulled up. Then, the torque of the ISG is adjusted according to the difference between the phase angle when the speed of the engine after torque relief drops to zero and the expected phase angle, so that the difference between the phase angle when the speed of the engine after torque relief drops to zero and the expected phase angle is less than or equal to a threshold value.

[0102] In the embodiment of the present application, after the engine speed drops to zero after torque unloading, the engine phase angle is controlled, which can effectively avoid the problem of engine reversal caused by the delay of ISG torque response and effectively improve the control accuracy of the phase angle.

[0103] Based on this, the present application provides an engine shutdown method, which can unload the engine torque based on the negative torque corresponding to the ISG, and control the engine speed after unloading to drop to zero according to the expected change rate of the shutdown target speed based on the feedforward torque, which can effectively alleviate the vibration of the engine during the shutdown process, thereby improving the user's driving experience. At the same time, the present application controls the phase angle of the engine to reduce the resistance when the engine is restarted, improve the success rate of the engine restarting, reduce the vibration when the engine is started, and improve the user's driving experience.

[0104] The present application provides an engine stopping device, see Figure 5 , this figure is a structural schematic diagram of an engine shutdown device provided in an embodiment of the present application. Its specific implementation method is consistent with the implementation method and the technical effect achieved in the embodiment of the above method, and some contents will not be repeated here.

[0105] Specifically, the present application provides an engine stopping device 1100, comprising:

[0106] A torque relief unit 1101, a calculation unit 1102, and a speed reduction unit 1103;

[0107] The torque unloading unit 1101 is used to control the engine speed to a shutdown target speed in a closed loop based on the integrated starter generator ISG, adjust the engine torque to the target torque, and obtain the engine after torque unloading, wherein the engine torque matches the negative torque corresponding to the ISG;

[0108] The calculation unit 1102 is used to calculate the feedforward torque according to the shutdown target speed and the expected change rate of the shutdown target speed;

[0109] The speed reduction unit 1103 is used to reduce the speed of the engine after torque relief from the shutdown target speed to zero based on the feed-forward torque.

[0110] In a possible implementation, the computing unit includes:

[0111] A calculation subunit and a correction subunit;

[0112] The calculation subunit is used to calculate the initial feed-forward torque according to the shutdown target speed and the expected change rate of the shutdown target speed;

[0113] The correction subunit is used to correct the initial feedforward torque according to the difference between the expected speed of the engine after torque unloading and the shutdown target speed to obtain the feedforward torque.

[0114] In a possible implementation, the calculation unit is specifically used to: calculate the feedforward torque according to the shutdown target speed, the expected change rate of the shutdown target speed, and the expected change rate of the phase angle of the engine after torque unloading;

[0115] The deceleration unit is specifically used to: based on the feedforward torque, reduce the speed of the engine after torque relief from the shutdown target speed to zero, and control the phase angle of the engine after torque relief in the shutdown state within a preset range.

[0116] In a possible implementation, the device further includes: a correction unit;

[0117] The correction unit is used to correct the feed-forward torque to obtain a corrected feed-forward torque;

[0118] The deceleration unit is specifically used to: based on the corrected feed-forward torque, reduce the speed of the engine after torque relief from the shutdown target speed to zero, and control the phase angle of the engine after torque relief in the shutdown state within a preset range.

[0119] In a possible implementation, the device further includes: an adjustment unit;

[0120] The regulating unit is used to adjust the phase angle when the speed of the engine after torque unloading drops to zero, so that the difference between the phase angle when the speed of the engine after torque unloading drops to zero and the expected phase angle is less than or equal to a threshold.

[0121] In a possible implementation, the torque relief unit includes: a speed regulating subunit and a torque relief subunit;

[0122] The speed regulating subunit is used to regulate the speed of the engine to obtain a regulated engine, wherein the torque of the regulated engine matches the negative torque corresponding to the ISG;

[0123] The torque unloading subunit is used to control the speed of the adjusted engine to a shutdown target speed in a closed loop based on the ISG, adjust the torque of the adjusted engine to a target torque, and obtain a torque-unloaded engine.

[0124] In a possible implementation, the torque unloading unit is specifically used to: based on the integrated starter generator ISG, control the engine speed in a closed loop to a shutdown target speed, adjust the engine torque to a target torque according to a preset slope, and obtain a torque-unloaded engine.

[0125] In summary, the present application provides an engine shutdown device, which can unload the torque of the engine based on the ISG, and based on the feedforward torque, control the speed of the engine after the torque unloading to drop to zero according to the expected change rate of the shutdown target speed, which can effectively alleviate the vibration of the engine during the shutdown process, thereby improving the user's driving experience. At the same time, due to the different phase angles of the engine shaft, the corresponding resistance when the engine is restarted is different. In the present application, the phase angle of the engine is controlled during shutdown to reduce the resistance when the engine is restarted, thereby improving the success rate of the engine restarting, reducing the vibration when the engine is started, and improving the user's driving experience.

[0126] The present application provides a computer device, the computer device comprising: a processor and a memory;

[0127] The memory is used to store program code and transmit the program code to the processor;

[0128] The processor is used to execute the steps of the engine shutdown method as described above according to the instructions in the program code.

[0129] The present application provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of an engine shutdown method as described above are implemented.

[0130] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An engine shutdown method, It is characterized in that include: Based on the integrated starter generator ISG, the speed of the engine is controlled in a closed loop to a shutdown target speed, the torque of the engine is adjusted to the target torque, and the engine after torque removal is obtained, and the torque of the engine matches the negative torque corresponding to the ISG; calculating a feedforward torque according to the shutdown target speed and an expected rate of change of the shutdown target speed; Based on the feed-forward torque, the speed of the engine after torque relief is reduced from the shutdown target speed to zero.

2. The method according to claim 1, It is characterized in that The calculating the feedforward torque according to the shutdown target speed and the expected change rate of the shutdown target speed includes: calculating an initial feed-forward torque according to the shutdown target speed and an expected rate of change of the shutdown target speed; According to the difference between the expected rotation speed of the engine after torque unloading and the shutdown target rotation speed, the initial feed-forward torque is corrected to obtain the feed-forward torque.

3. The method according to claim 1, It is characterized in that The calculating the feedforward torque according to the shutdown target speed and the expected change rate of the shutdown target speed includes: Calculating a feedforward torque according to the shutdown target speed, the expected rate of change of the shutdown target speed, and the expected rate of change of the phase angle of the engine after torque unloading; The step of reducing the speed of the engine after torque relief from the shutdown target speed to zero based on the feedforward torque includes: Based on the feed-forward torque, the speed of the engine after torque relief is reduced from the shutdown target speed to zero, and the phase angle of the engine after torque relief in the shutdown state is controlled within a preset range.

4. The method according to claim 3, It is characterized in that After calculating the feedforward torque according to the shutdown target speed, the expected change rate of the shutdown target speed, and the expected change rate of the phase angle of the engine after torque unloading, the method further includes: Correcting the feed-forward torque to obtain a corrected feed-forward torque; Based on the feedforward torque, the speed of the engine after torque relief is reduced from the shutdown target speed to zero, and the phase angle of the engine after torque relief is controlled within a preset range when the engine is in a shutdown state, including: Based on the corrected feed-forward torque, the speed of the engine after torque relief is reduced from the shutdown target speed to zero, and the phase angle of the engine after torque relief in the shutdown state is controlled within a preset range.

5. The method according to claim 1, It is characterized in that After reducing the speed of the engine after torque relief from the shutdown target speed to zero based on the feedforward torque, the method further includes: The phase angle when the rotation speed of the engine after torque relief drops to zero is adjusted so that the difference between the phase angle when the rotation speed of the engine after torque relief drops to zero and the expected phase angle is less than or equal to a threshold value.

6. The method according to claim 1, It is characterized in that The method of controlling the speed of the engine to a shutdown target speed in a closed loop based on the integrated starter generator (ISG), adjusting the torque of the engine to a target torque, and obtaining a torque-removed engine, wherein the torque of the engine matches the negative torque corresponding to the ISG, includes: Adjusting the speed of the engine to obtain an adjusted engine, wherein the torque of the adjusted engine matches the negative torque corresponding to the ISG; Based on the ISG, the speed of the adjusted engine is controlled in a closed loop to reach the shutdown target speed, and the torque of the adjusted engine is adjusted to the target torque to obtain a torque-relieved engine.

7. The method according to claim 1, It is characterized in that The method of controlling the speed of the engine to a shutdown target speed in a closed loop based on the integrated starter generator (ISG), adjusting the torque of the engine to a target torque, and obtaining a torque-relieved engine includes: Based on the integrated starter generator ISG, the speed of the engine is controlled in a closed loop to reach the shutdown target speed, and the torque of the engine is adjusted to the target torque according to a preset slope to obtain a torque-relieved engine.

8. An engine stop device, It is characterized in that include: Torque relief unit, calculation unit, and speed reduction unit; The torque unloading unit is used to control the speed of the engine to a shutdown target speed in a closed loop based on the integrated starter generator ISG, adjust the torque of the engine to the target torque, and obtain the engine after torque unloading, wherein the torque of the engine matches the negative torque corresponding to the ISG; The calculation unit is used to calculate the feedforward torque according to the shutdown target speed and the expected change rate of the shutdown target speed; The speed reduction unit is used to reduce the speed of the engine after torque relief from the shutdown target speed to zero based on the feedforward torque.

9. A computer device, It is characterized in that The computer device comprises: a processor and a memory; The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the steps of an engine shutdown method as described in any one of claims 1-7 according to the instructions in the program code.

10. A computer-readable storage medium, It is characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of an engine shutdown method according to any one of claims 1 to 7 are implemented.

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