An automatic transmission control method, device, equipment and storage medium

Abstract

This invention discloses an automatic transmission control method, device, equipment, and storage medium. The method includes: if the engine is in a running state and the transmission output shaft speed is 0 rpm; or, the transmission input shaft speed is greater than a first speed threshold for a duration equal to a first time threshold, and the engine speed is greater than a second speed threshold for a duration equal to the first time threshold; then determine that the automatic transmission's operating state matches the engine shutdown matching condition; when the automatic transmission's operating state matches the engine shutdown matching condition, if the gear is a forward or reverse gear, determine whether the engine speed is less than a third speed threshold for a duration equal to the second time threshold; if so, determine that the automatic transmission enters a shutdown protection state; when the automatic transmission enters the shutdown protection state, store a flag corresponding to the shutdown protection state, and control the automatic transmission to be placed in the engine shutdown protection mode.

Description

Technical Field

[0001] The embodiments of the present invention relate to engine control technology, and more particularly to an automatic transmission control method, device, equipment and storage medium. Background Technology

[0002] Automatic transmissions are designed with engine stall protection in mind during product development. When a vehicle is braking or coasting to reduce speed, and the engine speed is approaching the target idle speed, the automatic transmission will downshift according to its downshift point. The transmission control unit selects a lower gear with a higher gear ratio, increasing the engine speed during downshifting. As the vehicle approaches a stop, the automatic transmission reduces the clutch torque to 0 Nm. Since no load is applied to the engine, it maintains idle speed, awaiting the next start-up.

[0003] During vehicle start-up, the transmission control unit controls the clutch pressure to slowly apply clutch torque to the engine. Based on the deviation between the engine speed and the target engine speed, the clutch pressure is controlled to further control the torque applied to the engine, thus achieving a smooth and linear transmission of torque from the engine to the vehicle.

[0004] However, in actual vehicles, engine-related issues can cause the engine to stall during crawling or starting. These issues can include: running out of fuel, electrical faults on the engine side, unstable engine torque output, a stuck torque converter lock-up valve, or excessive torque being rapidly applied to the transmission. Even after restarting the engine and shifting into Drive, releasing the brake may cause the engine to stall again. This cycle can repeat, rendering the vehicle immobile. In urban areas, this can lead to traffic congestion; at highway speeds, it could result in accidents. Summary of the Invention

[0005] This invention provides an automatic transmission control method, device, equipment, and storage medium to reduce the frequent engine stalling during start-stop processes.

[0006] In a first aspect, embodiments of the present invention provide an automatic transmission control method, comprising:

[0007] If the engine is in the start state and the transmission output shaft speed is 0 rpm; or, the transmission input shaft speed is greater than a first speed threshold and the duration is a first time threshold, or the engine speed is greater than a second speed threshold and the duration is the first time threshold;

[0008] Then it is determined that the operating state of the automatic transmission matches the engine shutdown matching condition.

[0009] When the operating state of the automatic transmission matches the engine shutdown matching condition, if the gear is forward or reverse, it is determined whether the engine speed is less than the third speed threshold and the duration is the second time threshold.

[0010] If so, the automatic transmission is determined to have entered the engine shutdown protection state;

[0011] When the automatic transmission enters the engine shutdown protection state, it stores a flag corresponding to the engine shutdown protection state and controls the automatic transmission to be placed in the engine shutdown protection mode.

[0012] Optionally, after storing the flag bit corresponding to the flameout protection state, the system further includes:

[0013] If the engine is not started and a UDS-$14 service message is received, the flag bit is cleared, and the automatic transmission is controlled to exit the engine shutdown protection mode.

[0014] Optionally, after storing the flag bit corresponding to the flameout protection state, the system further includes:

[0015] If the engine speed reaches the fourth speed threshold, the engine's effective torque is greater than the torque threshold, the gear is in a forward gear, the vehicle speed is greater than the vehicle speed threshold, and the absolute value of the difference between the engine speed and the transmission input shaft speed is less than the fifth speed threshold and the duration is the third time threshold;

[0016] Then clear the flag bit and control the automatic transmission to exit the engine shutdown protection mode.

[0017] Optionally, when the automatic transmission is placed in the engine shutdown protection mode, it includes:

[0018] If the engine is started and the gear is forward or reverse, the control will not fill the clutch with oil.

[0019] When the brake is released and the accelerator is not depressed, the control prevents the clutch from transmitting engine torque.

[0020] Optionally, when the automatic transmission is placed in the engine shutdown protection mode, it includes:

[0021] If the engine is started and the gear is forward or reverse, the control will not fill the clutch with oil.

[0022] When the brake is released and the accelerator is depressed, if the engine speed is greater than the sixth speed threshold, the clutch pressure is controlled with the desired engine speed as the control target.

[0023] Optionally, before determining whether the engine's operating state matches the engine shutdown protection conditions, the following may also be included:

[0024] Determine whether the engine control unit and the automatic transmission control unit can communicate normally, whether the automatic transmission sensors are fault-free, whether the automatic transmission solenoid valves are fault-free, and whether the battery voltage is greater than the voltage threshold.

[0025] If so, then continue to determine whether the engine's operating state matches the engine shutdown protection conditions.

[0026] Optionally, when controlling the automatic transmission to be in the engine shutdown protection mode, it also includes:

[0027] Controls disable the automatic transmission's pressure self-learning function and torque converter lock-up function.

[0028] Secondly, embodiments of the present invention also provide an automatic transmission control device, including an automatic transmission control unit, the automatic transmission control unit being used for:

[0029] If the engine is in the start state and the transmission output shaft speed is 0 rpm; or, the transmission input shaft speed is greater than a first speed threshold and the duration is a first time threshold, or the engine speed is greater than a second speed threshold and the duration is the first time threshold;

[0030] Then it is determined that the operating state of the automatic transmission matches the engine shutdown matching condition.

[0031] When the operating state of the automatic transmission matches the engine shutdown matching condition, if the gear is forward or reverse, it is determined whether the engine speed is less than the third speed threshold and the duration is the second time threshold.

[0032] If so, the automatic transmission is determined to have entered the engine shutdown protection state;

[0033] When the automatic transmission enters the engine shutdown protection state, it stores a flag corresponding to the engine shutdown protection state and controls the automatic transmission to be placed in the engine shutdown protection mode.

[0034] Thirdly, embodiments of the present invention also provide an electronic device, including at least one processor and a memory communicatively connected to the at least one processor;

[0035] The memory stores a computer program that can be executed by the at least one processor, which enables the at least one processor to execute any of the automatic transmission control methods described in the embodiments of the present invention.

[0036] Fourthly, embodiments of the present invention also provide a computer-readable storage medium storing computer instructions, which are used to cause a processor to execute any of the automatic transmission control methods described in the embodiments of the present invention.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention proposes an automatic transmission control method, in which the engine speed, automatic transmission input shaft speed, automatic transmission output shaft speed and gear position are used to determine whether the engine has entered the engine shutdown protection state. When the engine shutdown protection state is entered, the automatic transmission is controlled to be placed in the engine shutdown protection mode, thereby enabling the vehicle to gradually start during the start-up phase and realizing the vehicle's continued drivability. In addition, when the automatic transmission is determined to have entered the engine shutdown protection state, the state is stored in a non-volatile data storage area. As long as the exit condition of the strategy is not met, the protection strategy can be continuously implemented without being affected by repeated power-on and power-off operations of the vehicle, effectively implementing the transmission's engine shutdown protection strategy and enabling the vehicle to remain mobile in abnormal states. Attached Figure Description

[0038] Figure 1 This is a flowchart of the automatic transmission control method in the embodiment;

[0039] Figure 2 This is a target engine speed curve diagram in the embodiment;

[0040] Figure 3 This is a flowchart of another automatic transmission control method in the embodiment;

[0041] Figure 4 This is a flowchart of another automatic transmission control method in the embodiments;

[0042] Figure 5 This is a flowchart of another automatic transmission control method in the embodiments;

[0043] Figure 6 This is a schematic diagram of the electronic device structure in the embodiment. Detailed Implementation

[0044] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0045] Example 1

[0046] Figure 1 This is a flowchart of the automatic transmission control method in the embodiment, for reference. Figure 1 Automatic transmission control methods include:

[0047] S101. Determine whether the operating status of the automatic transmission matches the engine shutdown matching condition.

[0048] In this embodiment, the determination of whether the operating state of the automatic transmission matches the engine shutdown matching condition is made in the following manner:

[0049] If the engine is running and the transmission output shaft speed is 0 rpm;

[0050] Alternatively, the speed of the transmission input shaft is greater than a first speed threshold and the duration is a first time threshold, and the speed of the engine is greater than a second speed threshold and the duration is the first time threshold;

[0051] Then it is determined that the operating state of the automatic transmission matches the engine shutdown matching condition.

[0052] For example, in this embodiment, the transmission output shaft is set to the output shaft of the automatic transmission, and the transmission input shaft is set to the input shaft of the automatic transmission.

[0053] S102. When the engine's operating state matches the engine shutdown matching condition, determine whether the automatic transmission has entered the shutdown protection state.

[0054] In this embodiment, the determination of whether the automatic transmission has entered the engine shutdown protection state is made in the following manner:

[0055] When the gear is forward or reverse, determine whether the engine speed is less than the third speed threshold and the duration is the second time threshold;

[0056] If so, the automatic transmission is determined to have entered the engine shutdown protection state.

[0057] S103. When the automatic transmission enters the engine shutdown protection state, store the flag bit corresponding to the engine shutdown protection state and control the automatic transmission to be placed in the engine shutdown protection mode.

[0058] For example, in this embodiment, a flag is set to indicate whether the engine has entered the engine shutdown protection state;

[0059] For example, the flag can be set to EngStall_Flag. When the engine enters the engine shutdown protection state, EngStall_Flag is False. When the engine does not enter the engine shutdown protection state, EngStall_Flag can be set to True or empty.

[0060] For example, in this embodiment, the above-mentioned flag bit can be stored in storage space or memory (e.g., EEPROM). When the controller (system) is started multiple times, the stored flag bit can be used to determine whether the automatic transmission is in the engine shutdown protection state.

[0061] In this embodiment, if the automatic transmission is in an engine shutdown protection state, the automatic transmission is controlled to be placed in an engine shutdown protection mode.

[0062] For example, in this embodiment, the engine shutdown protection mode is used to prevent the engine from stalling during the start-up phase. When the automatic transmission is in the engine shutdown protection mode, the torque applied to the engine can be controlled by controlling the amount of oil filling the clutch and the clutch pressure in the automatic transmission, thereby preventing the engine from stalling during the start-up phase.

[0063] This embodiment proposes an automatic transmission control method. In this method, the automatic transmission is judged to have entered an engine shutdown protection state based on the engine speed, the input shaft speed of the automatic transmission, the output shaft speed of the automatic transmission, and the gear position. When the engine shutdown protection state is entered, the automatic transmission is controlled to be placed in the engine shutdown protection mode, thereby enabling the vehicle to gradually start during the start-up phase and realizing the vehicle's continued drivability. In addition, when the engine is determined to have entered the engine shutdown protection state, the state is stored in a non-volatile data storage area. As long as the exit condition of the strategy is not met, the protection strategy can be continuously implemented without being affected by repeated power-on and power-off operations of the vehicle, effectively implementing the transmission's engine shutdown protection strategy and enabling the vehicle to remain mobile in abnormal states.

[0064] exist Figure 1 Based on the scheme shown, in one possible implementation, after storing the flag corresponding to the flameout protection state, the following is also included:

[0065] If the engine is not started and a UDS-$14 service message is received, the flag is cleared and the automatic transmission is controlled to exit the engine shutdown protection mode.

[0066] In this solution, the UDS-$14 service information specifically refers to the diagnostic fault clearing service (0x14) specified in the UDS (Unified Diagnostic Services) diagnostic protocol. The specific encoding method of this service information is not limited and can be freely set according to requirements.

[0067] For example, the UDS-$14 service information can be encoded as 0xFFFFFF, which is used to clear all fault codes (including flag bits) stored (within the controller).

[0068] For example, in this solution, when the flag bit is cleared to empty or the flag bit is True, the automatic transmission is controlled to exit the engine shutdown protection mode. At this time, the control strategy related to the engine shutdown protection mode is no longer executed during the start-up phase.

[0069] exist Figure 1 Based on the scheme shown, in one possible implementation, after storing the flag corresponding to the flameout protection state, the following is also included:

[0070] If the engine speed reaches the fourth speed threshold, the engine's effective torque is greater than the torque threshold, the gear is in a forward gear, the vehicle speed is greater than the vehicle speed threshold, and the absolute value of the difference between the engine speed and the transmission input shaft speed is less than the fifth speed threshold and the duration is the third time threshold.

[0071] Then clear the flag and control the automatic transmission to exit the engine shutdown protection mode.

[0072] For example, in this solution, there is no limitation on the way to clear the flag bit. For example, the flag bit can be set to True or empty.

[0073] For example, in this solution, when the flag bit is cleared to empty or the flag bit is True, the automatic transmission is controlled to exit the engine shutdown protection mode. At this time, the control strategy related to the engine shutdown protection mode is no longer executed during the start-up phase.

[0074] exist Figure 1 Based on the illustrated scheme, in one possible implementation, when the automatic transmission is placed in the engine shutdown protection mode, it includes:

[0075] If the engine is started and the gear is in forward or reverse, the control will not fill the clutch with oil.

[0076] When the brake is released and the accelerator is not depressed, the control prevents the clutch from transmitting engine torque.

[0077] For example, in this solution, when the clutch (in the automatic transmission) is controlled to prevent the transmission of engine torque, the vehicle does not have a crawling function. In this state, the engine can be stably idled and the engine speed can be stably maintained within the target idle speed range.

[0078] When the engine achieves stable idle speed control, it can avoid uneven torque output and speed fluctuations in the low-speed range, thereby preventing frequent engine stalling.

[0079] exist Figure 1 Based on the illustrated scheme, in one possible implementation, when the automatic transmission is placed in the engine shutdown protection mode, it includes:

[0080] If the engine is started and the gear is in forward or reverse, the control will not fill the clutch with oil.

[0081] When the brake is released and the accelerator is depressed, if the engine speed is greater than the sixth speed threshold, the clutch pressure is controlled with the desired engine speed as the control target.

[0082] Figure 2 This is a target engine speed curve from the embodiment, for reference. Figure 2 In this scheme, the desired engine speed is used as the control target, and the clutch engagement pressure (in the automatic transmission) is controlled so that the engine speed changes according to the desired engine speed target curve.

[0083] For example, in this solution, the desired engine speed can be used as the input and the clutch engagement pressure as the output. A process feedback control equation (e.g., a PID control equation) can be used to determine the clutch engagement pressure based on the feedback control equation.

[0084] For example, in this solution, after determining the engagement pressure, the engagement pressure can be converted into the amount of oil to be injected into the clutch. Then, by controlling the amount of oil injected into the clutch, the torque of the clutch is gradually applied to the engine, so that the engine speed changes according to the curve trajectory of the desired engine speed.

[0085] exist Figure 1 Based on the scheme shown, in one possible implementation, before determining whether the operating state of the automatic transmission matches the engine shutdown protection condition, the following further step is included:

[0086] Determine whether the engine control unit and the automatic transmission control unit can communicate normally, whether the automatic transmission sensors are fault-free, whether the automatic transmission solenoid valves are fault-free, and whether the battery voltage is greater than the voltage threshold.

[0087] If so, then continue to determine whether the operating status of the automatic transmission matches the engine shutdown protection conditions.

[0088] In this embodiment, when the engine control unit and the automatic transmission control unit can communicate normally, the automatic transmission sensors are fault-free, the automatic transmission solenoid valves are fault-free, and the battery voltage is greater than the voltage threshold, the system continues to determine whether the engine's operating state matches the engine shutdown protection conditions, that is:

[0089] Determine if the engine is running and the transmission output shaft speed is 0 rpm;

[0090] Alternatively, the speed of the transmission input shaft is greater than a first speed threshold and the duration is a first time threshold, and the speed of the engine is greater than a second speed threshold and the duration is the first time threshold;

[0091] When at least one of the above two conditions is met, the engine's operating state is determined to match the engine shutdown protection condition.

[0092] exist Figure 1 Based on the illustrated scheme, in one possible implementation, when controlling the automatic transmission to be in engine shutdown protection mode, the following further applies:

[0093] Controls include the automatic transmission's pressure self-learning function and the torque converter lock-up function.

[0094] For example, an automatic transmission can be configured to include multiple control modes (corresponding to pressure self-learning function and torque converter lock-up function), wherein the automatic transmission engine shutdown protection mode is set as one of the control modes;

[0095] When the automatic transmission is set to engine shutdown protection mode, it is prohibited to automatically switch to other control modes before exiting engine shutdown protection mode;

[0096] After the automatic transmission exits the engine shutdown protection mode, it executes a control mode configured internally according to the preset control logic, depending on the vehicle or engine operating conditions.

[0097] For example, in this solution, the pressure self-learning function and the hydraulic torque converter lock-up function are implemented in the same way as in the prior art, and the specific details will not be elaborated further.

[0098] Figure 3 This is a flowchart of another automatic transmission control method in the embodiment, see reference. Figure 3 In one possible implementation, the automatic transmission control method includes:

[0099] S201. Determine whether the engine system meets the prerequisites for engine shutdown detection.

[0100] In this scheme, when the engine control unit and the automatic transmission control unit can communicate normally, the automatic transmission sensors are fault-free, the automatic transmission solenoid valves are fault-free, and the battery voltage is greater than the voltage threshold, the engine system is determined to meet the preconditions for engine shutdown detection.

[0101] For example, in this solution, the voltage threshold is set to 12V.

[0102] S202. Determine whether the operating status of the automatic transmission matches the engine shutdown matching condition.

[0103] In this scheme, the automatic transmission's operating state is matched with the engine shutdown condition if the following conditions are met:

[0104] The engine is running and the transmission output shaft is rotating at 0 rpm.

[0105] Alternatively, the speed of the transmission input shaft is greater than a first speed threshold and the duration is a first time threshold, or the speed of the engine is greater than a second speed threshold and the duration is the first time threshold.

[0106] For example, in this solution, the first speed threshold is set to 500 rpm, the second speed threshold is set to 400 rpm, and the first time threshold is set to 500 ms.

[0107] S203. When the operating state of the automatic transmission matches the engine shutdown matching condition, determine whether the automatic transmission has entered the shutdown protection state.

[0108] In this scheme, the automatic transmission is determined to enter the engine shutdown protection state when the following conditions are met:

[0109] The gear is forward or reverse, the engine speed is less than the third speed threshold, and the duration is the second time threshold.

[0110] For example, in this scheme, the third speed threshold is 100 rpm and the second time threshold is 1 s.

[0111] S204. When the automatic transmission enters the engine shutdown protection state, store the flag bit corresponding to the engine shutdown protection state and control the automatic transmission to be placed in the engine shutdown protection mode.

[0112] For example, in this solution, the variable EngStall_Flag is set to False when the engine enters the engine shutdown protection state and True when it exits the engine shutdown protection state.

[0113] For example, in this scheme, the variable EngStall_Flag and its assigned value are stored in a non-volatile cache EEPROM.

[0114] In this scheme, when the automatic transmission is in engine shutdown protection mode, the following strategy is executed:

[0115] If the engine is started and the gear is forward or reverse, the control will not fill the clutch with oil.

[0116] When the brake is released and the accelerator is not depressed, the control prevents the clutch from transmitting engine torque.

[0117] When the brake is released and the accelerator is depressed, if the engine speed is greater than the sixth speed threshold, the clutch pressure is controlled with the desired engine speed as the control target.

[0118] For example, in this solution, the sixth speed threshold is set to 1200 rpm.

[0119] In this scheme, when the automatic transmission is in engine shutdown protection mode, the automatic transmission's pressure self-learning function and torque converter lock-up function are simultaneously disabled.

[0120] S205. When the conditions for exiting the engine shutdown protection are met, control the automatic transmission to exit the engine shutdown protection mode.

[0121] In this scheme, the engine shutdown protection exit condition is determined to be met and the engine shutdown protection mode is exited when the following conditions are met:

[0122] The engine is not started and a UDS-$14 service message has been received. The automatic transmission has exited engine shutdown protection mode.

[0123] Alternatively, the engine speed reaches the fourth speed threshold and is less than the seventh speed threshold, the engine's effective torque is greater than the torque threshold, the gear is in the preset forward gear, the vehicle speed is greater than the vehicle speed threshold, or the absolute value of the difference between the engine speed and the transmission input shaft speed is less than the fifth speed threshold and the duration is the third time threshold.

[0124] Furthermore, if the above judgment is performed multiple times and the conditions in the judgment are met within a consecutive threshold number of times, the engine shutdown protection mode will be exited.

[0125] For example, in this scheme, the fourth speed threshold is 1000 rpm, the seventh speed threshold is 3000 rpm, the torque threshold is 60 Nm, the preset forward gear is 3rd gear, the vehicle speed threshold is 20 km / h, the fifth speed threshold is 30 rpm, the third time threshold is 0.5 s, and the number of consecutive thresholds is 8.

[0126] For example, in this solution, when it is determined that the conditions for exiting the flameout protection are met, the stored flag bit corresponding to the flameout protection status is also changed or cleared at the same time.

[0127] For example, in this solution, when the automatic transmission exits the engine shutdown protection mode, the automatic transmission's pressure self-learning function and torque converter lock-up function are simultaneously restored.

[0128] exist Figure 1 Based on the beneficial effects of the proposed solution, this solution also includes the following beneficial effects: a strategy for exiting the engine shutdown protection mode is set. By checking the engine speed, engine torque, and transmission clutch speed, it is possible to effectively determine whether the engine has been repaired. If the fault has been repaired, the engine shutdown protection mode is automatically exited, and the vehicle's overall control is restored without human intervention.

[0129] Example 2

[0130] Figure 4 This is a flowchart of the automatic transmission control method in the embodiment, for reference. Figure 1 Automatic transmission control methods include:

[0131] S301. Determine whether the vehicle is in forward or reverse gear. If so, determine whether the engine's operating status matches the engine shutdown protection conditions.

[0132] In this embodiment, an engine shutdown protection condition is set as the basis for determining whether the engine will stall when the vehicle starts moving from a stop.

[0133] In this embodiment, engine shutdown protection conditions can be set according to preset reasons for engine shutdown. For example, when the throttle opening is abnormal, the engine torque output is not smooth, the engine speed fluctuates, and / or the automatic transmission torque converter locks up, the engine's working state can be considered to match the engine shutdown protection conditions.

[0134] S302. If the engine's operating state matches the engine shutdown protection conditions, control the automatic transmission to be placed in the engine shutdown protection mode.

[0135] In this embodiment, the automatic transmission can be configured to include multiple control modes, wherein the engine shutdown protection mode is set as one of the control modes;

[0136] Specifically, when the automatic transmission is set to engine shutdown protection mode, it is prohibited to automatically switch to other control modes before exiting engine shutdown protection mode.

[0137] S303. When the automatic transmission is in engine shutdown protection mode, obtain the status of the brake pedal and the accelerator pedal.

[0138] In this embodiment, the brake pedal state includes at least whether the brake pedal is depressed, and the accelerator pedal state includes at least whether the accelerator pedal is depressed.

[0139] S304. When the brake pedal is released and the accelerator pedal is not depressed, control the automatic transmission not to load the engine.

[0140] For example, in this embodiment, the method of controlling the automatic transmission not to load the engine is not limited. For instance, the method of not loading the engine can be achieved as follows:

[0141] Controls prevent oil from being supplied to the clutches included in the automatic transmission, so that the clutches are not engaged with the engine. At this time, the load (such as the wheel system) is not loaded onto the engine through the clutch, and correspondingly, the engine does not transmit torque outward through the clutch.

[0142] Under the above conditions, the engine can stably achieve idle speed control, that is, the engine speed can be stably increased to the engine's target idle speed range.

[0143] S305. When the brake pedal is released and the accelerator pedal is depressed, if the engine speed reaches the sixth speed threshold, the automatic transmission is controlled to apply load to the engine.

[0144] In this embodiment, when the accelerator pedal is pressed, the engine is kept from being loaded until the engine speed (idle speed) reaches the sixth speed threshold.

[0145] After the engine speed reaches the sixth speed threshold, the automatic transmission is then controlled to apply load to the engine. The method for controlling the automatic transmission to apply load to the engine can be as follows:

[0146] Oil is supplied to the clutch at a certain rate, thereby causing the clutch to complete the process of disengaging from the engine and fully engaging with the engine at a certain rate of movement (or the rate of pressure change between the clutch and the engine).

[0147] S306. When the engine's output torque exceeds the torque threshold, control the automatic transmission to exit the engine shutdown protection mode.

[0148] In this embodiment, based on the contents recorded in steps S304 to S305, when the clutch is fully engaged with the engine and the engine output torque is greater than the torque threshold, the automatic transmission exits the engine shutdown protection mode.

[0149] After the automatic transmission exits the engine shutdown protection mode, it executes a control mode configured internally according to the preset control logic, depending on the vehicle or engine operating conditions.

[0150] This embodiment proposes an automatic transmission control method. In this method, when it is determined that the engine's operating state matches the engine shutdown protection condition, the automatic transmission enters the engine shutdown protection mode. In this mode, when the brake pedal is released and the accelerator pedal is not depressed, the automatic transmission is controlled not to load the engine. When the brake pedal is released and the accelerator pedal is depressed, if the engine speed reaches a first speed threshold, the clutch is controlled to load the engine. Based on this, the engine can be prevented from shutting down again after the vehicle is restarted, thus ensuring the vehicle's mobility.

[0151] In addition, when the engine's output torque exceeds the torque threshold, the automatic transmission automatically exits the engine shutdown protection mode and returns to the normal shifting mode, restoring vehicle control without human intervention.

[0152] exist Figure 3Based on the scheme shown, in one feasible implementation, determining whether the engine's operating state matches the engine shutdown protection conditions includes:

[0153] Determine if the engine speed is consistently below the third speed threshold. If so, determine if the engine's operating state matches the engine shutdown protection condition.

[0154] In this scheme, determining whether the engine speed is continuously lower than the third speed threshold is specifically as follows:

[0155] After the vehicle is in drive or reverse, determine whether the engine speed is lower than the third speed threshold and the duration is equal to the second time threshold after the brake pedal is released. If so, determine that the engine speed is continuously lower than the third speed threshold.

[0156] For example, in this scheme, the values ​​of the third speed threshold and the second time threshold can be determined empirically or through calibration tests.

[0157] Furthermore, when determining whether the engine's operating state matches the engine shutdown protection conditions by judging whether the engine speed is continuously lower than the third speed threshold, the determination of whether the vehicle's gear is automatic or reverse also includes:

[0158] Determine whether the engine is running and whether the output shaft speed of the automatic transmission is 0 rpm;

[0159] Alternatively, the speed of the transmission input shaft is greater than a first speed threshold and the duration is a first time threshold, and the speed of the engine is greater than a second speed threshold and the duration is the first time threshold;

[0160] If so, when the vehicle is in forward or reverse gear, determine whether the automatic transmission's operating state matches the engine shutdown protection conditions.

[0161] In this scheme, if either of the above two conditions is met, the subsequent determination of whether the automatic transmission is in engine shutdown protection mode will continue; if neither of the above two conditions is met, the subsequent determination of whether the automatic transmission is in engine shutdown protection mode will not be performed.

[0162] refer to Figure 2 ,exist Figure 4 Based on the scheme shown, controlling the automatic transmission to apply load to the engine includes:

[0163] The desired engine speed is used as the control target, and the engagement pressure of the clutch is controlled so that the engine speed changes according to the desired engine speed target curve.

[0164] For example, in this solution, the desired engine speed can be used as input and the engagement pressure of the automatic transmission can be used as output. A process feedback control equation (e.g., a PID control equation) can be used to determine the engagement pressure of the automatic transmission based on the feedback control equation.

[0165] For example, in this solution, after determining the engagement pressure, the engagement pressure can be converted into the amount of oil to be injected into the clutch. Then, by controlling the amount of oil injected into the clutch, the torque of the clutch is gradually applied to the engine, so that the engine speed changes according to the curve trajectory of the desired engine speed.

[0166] exist Figure 4 Based on the scheme shown, in one possible implementation, before controlling the automatic transmission to exit the engine shutdown protection mode, the following further steps are included:

[0167] The system determines whether the engine speed is greater than the fourth speed threshold and less than the seventh speed threshold, whether the automatic transmission gear is greater than the gear threshold, whether the vehicle speed is greater than the vehicle speed threshold, and whether the absolute value of the difference between the engine speed and the transmission input shaft speed is less than the fifth speed threshold and the duration is the third time threshold.

[0168] In this scheme, if the engine speed is greater than the fourth speed threshold and less than the seventh speed threshold, the automatic transmission gear is greater than the gear threshold, the vehicle speed is greater than the vehicle speed threshold, the absolute value of the difference between the engine speed and the transmission input shaft speed is less than the fifth speed threshold and the duration is the third time threshold, and the engine output torque is greater than the torque threshold, then the automatic transmission is controlled to exit the engine shutdown protection mode.

[0169] For example, in this scheme, the fourth speed threshold, the fifth speed threshold, the seventh speed threshold, the gear threshold, the vehicle speed threshold, and the torque threshold can be determined through experience or calibration tests.

[0170] exist Figure 4 Based on the scheme shown, in one possible implementation, before determining whether the engine's operating state matches the engine shutdown protection conditions, the following further step is taken:

[0171] Determine whether the engine control unit and the automatic transmission control unit can communicate normally, whether the automatic transmission sensors are fault-free, whether the automatic transmission solenoid valves are fault-free, and whether the battery voltage is greater than the voltage threshold.

[0172] If yes, then continue to determine whether the operating state of the automatic transmission matches the engine shutdown protection conditions; if not, then do not proceed with the subsequent determination of whether the operating state of the automatic transmission matches the engine shutdown protection conditions, that is, the automatic transmission will not be put into engine shutdown protection mode.

[0173] For example, in this embodiment, the schemes corresponding to any of the above-mentioned automatic transmission control methods can be freely arranged and combined. Figure 5 This is a flowchart of another automatic transmission control method in the embodiment, see reference. Figure 5 For example, in one possible implementation, the automatic transmission control method includes:

[0174] S401. Determine whether the vehicle is in a stopped state. If so, record it as satisfying condition one.

[0175] For example, in this solution, whether the vehicle is in a stopped state can be determined by the vehicle speed or the output shaft speed of the automatic transmission. For instance, if the vehicle speed is zero, it can be determined that the vehicle is in a stopped state.

[0176] S402. Determine whether the engine control unit and the automatic transmission control unit can communicate normally, whether the automatic transmission sensors are fault-free, whether the automatic transmission solenoid valves are fault-free, and whether the battery voltage is greater than the voltage threshold. If so, it is recorded as satisfying condition two.

[0177] For example, in this solution, it can be determined whether the engine control unit (ECU) and the automatic transmission control unit (TCU) can communicate normally based on the (CAN) communication frames between them.

[0178] The fault-free status of the automatic transmission sensors and automatic transmission solenoids can be determined by the communication frames or test procedures between the TCU and the automatic transmission sensors and automatic transmission solenoids.

[0179] Whether the battery voltage is greater than the voltage threshold can be determined by collecting battery voltage data from the Battery Management System (BMS).

[0180] For example, in this solution, the voltage threshold is set to 12V.

[0181] S403. Determine whether the engine is in the starting state and whether the output shaft speed of the automatic transmission is 0 rpm; or, the speed of the transmission input shaft is greater than the first speed threshold and the duration is the first time threshold, and the engine speed is greater than the second speed threshold and the duration is the first time threshold. If so, it is recorded as satisfying condition three.

[0182] For example, in this solution, determining whether the difference between the input shaft speed of the automatic transmission and the engine speed remains at a first speed difference can be specifically as follows:

[0183] Determine whether the input shaft speed of the automatic transmission is greater than 500 rpm and the duration of the 500 rpm time is greater than 500 ms, and whether the engine speed is greater than 400 rpm and the duration of the 400 rpm time is greater than 500 ms.

[0184] In this scheme, the first speed threshold is set to 500 rpm, the second speed threshold is set to 400 rpm, and the first time threshold is set to 500 ms.

[0185] S404. Determine whether the vehicle is in forward or reverse gear. If so, it is considered to meet condition four.

[0186] S405. If conditions one to four are met, determine whether the engine speed is continuously less than the third speed threshold. If so, determine that the engine's operating state matches the engine shutdown protection condition and control the automatic transmission to be placed in the engine shutdown protection mode.

[0187] For example, in this solution, determining whether the engine speed is continuously lower than the third speed threshold specifically involves:

[0188] Determine if the engine speed is less than 100 rpm and the duration of the less than 100 rpm speed is greater than 1 second.

[0189] For example, in this solution, after entering the engine shutdown protection mode, the engine shutdown protection state EngStall_Flag is set to False, and the EngStall_Flag state is stored in the TCU's non-volatile cache EEPROM.

[0190] S406. When the automatic transmission is in engine shutdown protection mode, control disables the automatic transmission's pressure self-learning function and torque converter lock-up function.

[0191] For example, in this solution, the functions of pressure self-learning and hydraulic torque converter lock-up are implemented in the same way as in the prior art, and their specific details will not be described in detail.

[0192] S407. When the brake pedal is released and the accelerator pedal is depressed, determine whether the engine speed has reached the sixth speed threshold. Before the engine speed reaches the sixth speed threshold, control the automatic transmission not to load the engine.

[0193] S408. After the engine speed reaches the sixth speed threshold, the engagement pressure of the automatic transmission is controlled with the desired engine speed as the control target, so that the engine speed changes according to the desired engine speed target curve.

[0194] In this solution, a TCU is configured to detect engine speed. When the engine speed exceeds the set sixth speed threshold, the clutch pressure is controlled with the desired engine speed as the control target. The clutch torque is gradually applied to the engine end, so that the engine speed changes according to the desired engine speed target curve, thereby enabling the vehicle to move.

[0195] For example, in this solution, the sixth speed threshold is set to 1200 rpm.

[0196] S409. Determine whether the engine speed is greater than the fourth speed threshold and less than the seventh speed threshold, whether the automatic transmission gear is greater than the gear threshold, whether the vehicle speed is greater than the vehicle speed threshold, whether the absolute value of the difference between the engine speed and the transmission input shaft speed is less than the fifth speed threshold and the duration is the third time threshold, and whether the engine output torque is greater than the torque threshold. If so, it is recorded as satisfying condition five.

[0197] For example, in this solution, the fourth speed threshold is set to 1000 rpm, the seventh speed threshold is set to 3000 rpm, the gear threshold is set to 3rd gear, the vehicle speed threshold is set to 20 km / h, the fifth speed threshold is set to 30 rpm, and the torque threshold is set to 60 Nm.

[0198] For example, in this solution, if the engine speed is greater than 1000 rpm and less than 3000 rpm, the automatic transmission is in D gear and the gear is greater than 3, the vehicle speed is greater than 20 km / h, and the engine output torque is greater than 60 Nm, then it is determined that the conditions for exiting the engine shutdown protection are met.

[0199] At this point, it is further determined whether the difference between the input shaft speed of the automatic transmission and the engine speed is less than 30 rpm. If the difference in speed is less than 30 rpm and the duration is greater than 0.5 seconds, then condition five is satisfied.

[0200] S410. If condition five is met, control the automatic transmission to exit the engine shutdown protection mode.

[0201] For example, in this solution, after exiting the engine shutdown protection mode, the engine shutdown protection state EngStall_Flag is set to True, the EngStall_Flag state is stored in the non-volatile cache EEPROM, the vehicle resumes the crawl function, the TCU enables the pressure self-learning function and the torque converter lock-up function, the TCU enables the adaptive shift function, and the vehicle functions return to normal.

[0202] exist Figure 1Based on the beneficial effects of the proposed solution, in this solution, the TCU has an engine shutdown protection mode. After this mode is triggered, the TCU does not immediately control the clutch pressure to apply the transmission load to the engine side. Instead, it detects when the driver releases the brake and presses the accelerator, and gradually applies torque to the engine side by controlling the clutch pressure, so that the vehicle can start gradually and achieve the continued drivability of the vehicle.

[0203] The TCU can automatically detect and identify the engine shutdown protection mode, implement engine shutdown protection control, and store the status in the TCU's non-volatile data storage area. As long as the exit conditions of the strategy are not met, the protection strategy can be implemented continuously, unaffected by repeated power-on and power-off operations of the vehicle, effectively implementing the transmission engine shutdown protection strategy and enabling the vehicle to remain mobile in abnormal conditions.

[0204] By checking engine speed, engine torque, and transmission clutch speed, it is possible to effectively determine whether the engine has been repaired. If the fault has been repaired, the TCU automatically exits the engine shutdown protection mode and restores vehicle control without human intervention.

[0205] Example 3

[0206] This embodiment proposes an automatic transmission control device, including an automatic transmission control unit, which is used for:

[0207] If the engine is in the started state and the transmission output shaft speed is 0 rpm; or, the transmission input shaft speed is greater than a first speed threshold and the duration is a first time threshold, and the engine speed is greater than a second speed threshold and the duration is a first time threshold;

[0208] Then it is determined that the operating state of the automatic transmission matches the engine shutdown matching condition.

[0209] When the automatic transmission's operating state matches the engine shutdown matching condition, if the gear is forward or reverse, it is determined whether the engine speed is less than the third speed threshold and the duration is the second time threshold.

[0210] If so, the automatic transmission is determined to have entered the engine shutdown protection state;

[0211] When the automatic transmission enters the engine shutdown protection state, it stores the flag corresponding to the engine shutdown protection state and controls the automatic transmission to be placed in the engine shutdown protection mode.

[0212] For example, in this embodiment, the automatic transmission control unit can be specifically configured to implement any of the automatic transmission control methods described in Embodiment 1. The implementation process and beneficial effects are the same as the corresponding content described in Embodiment 1, and will not be repeated here.

[0213] Example 4

[0214] Figure 6 A schematic diagram of an electronic device 10 that can be used to implement embodiments of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0215] like Figure 6 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 may also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0216] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of displays, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0217] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as automatic transmission control methods.

[0218] In some embodiments, the automatic transmission control method may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the automatic transmission control method described above may be performed. Alternatively, in other embodiments, processor 11 may be configured to perform the automatic transmission control method by any other suitable means (e.g., by means of firmware).

[0219] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0220] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0221] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0222] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0223] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0224] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0225] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. An automatic transmission control method, characterized in that, include: If the engine is in the start state and the transmission output shaft speed is 0 rpm; or, the transmission input shaft speed is greater than a first speed threshold and the duration is a first time threshold, or the engine speed is greater than a second speed threshold and the duration is the first time threshold; Then it is determined that the operating state of the automatic transmission matches the engine shutdown matching condition. When the operating state of the automatic transmission matches the engine shutdown matching condition, if the gear is forward or reverse, it is determined whether the engine speed is less than the third speed threshold and the duration is the second time threshold. If so, the automatic transmission is determined to have entered the engine shutdown protection state; When the automatic transmission enters the engine shutdown protection state, it stores the flag corresponding to the engine shutdown protection state and controls the automatic transmission to be placed in the engine shutdown protection mode. After storing the flag corresponding to the flameout protection state, the following is also included: If the engine is not started and UDS-$14 service information is received, the flag bit is cleared and the automatic transmission is controlled to exit the engine shutdown protection mode. After storing the flag corresponding to the flameout protection state, the following is also included: If the engine speed reaches the fourth speed threshold, the engine's effective torque is greater than the torque threshold, the gear is in a forward gear, the vehicle speed is greater than the vehicle speed threshold, and the absolute value of the difference between the engine speed and the transmission input shaft speed is less than the fifth speed threshold and the duration is the third time threshold; Then clear the flag bit and control the automatic transmission to exit the engine shutdown protection mode.

2. The automatic transmission control method as described in claim 1, characterized in that, When the automatic transmission is in the engine shutdown protection mode, it includes: If the engine is started and the gear is forward or reverse, the control will not fill the clutch with oil. When the brake is released and the accelerator is not depressed, the control prevents the clutch from transmitting engine torque.

3. The automatic transmission control method as described in claim 1, characterized in that, When the automatic transmission is in the engine shutdown protection mode, it includes: If the engine is started and the gear is forward or reverse, the control will not fill the clutch with oil. When the brake is released and the accelerator is depressed, if the engine speed is greater than the sixth speed threshold, the clutch pressure is controlled with the desired engine speed as the control target.

4. The automatic transmission control method as described in claim 1, characterized in that, Before determining whether the engine's operating condition matches the engine shutdown protection conditions, the following steps are also included: Determine whether the engine control unit and the automatic transmission control unit can communicate normally, whether the automatic transmission sensors are fault-free, whether the automatic transmission solenoid valves are fault-free, and whether the battery voltage is greater than the voltage threshold. If so, then continue to determine whether the engine's operating state matches the engine shutdown protection conditions.

5. The automatic transmission control method as described in claim 1, characterized in that, When controlling the automatic transmission to be in the engine shutdown protection mode, it also includes: Controls disable the automatic transmission's pressure self-learning function and torque converter lock-up function.

6. An automatic transmission control device, characterized in that, Includes an automatic transmission control unit, the automatic transmission control unit being used for: If the engine is in the start state and the transmission output shaft speed is 0 rpm; or, the transmission input shaft speed is greater than a first speed threshold and the duration is a first time threshold, or the engine speed is greater than a second speed threshold and the duration is the first time threshold; Then it is determined that the engine's operating state matches the engine shutdown matching condition. When the engine's operating state matches the engine shutdown matching condition, if the gear is forward or reverse, it is determined whether the engine speed is less than the third speed threshold and the duration is the second time threshold. If so, the automatic transmission is determined to have entered the engine shutdown protection state; When the automatic transmission enters the engine shutdown protection state, it stores the flag corresponding to the engine shutdown protection state and controls the automatic transmission to be placed in the engine shutdown protection mode. After storing the flag corresponding to the flameout protection state, the following is also included: If the engine is not started and UDS-$14 service information is received, the flag bit is cleared and the automatic transmission is controlled to exit the engine shutdown protection mode. After storing the flag corresponding to the flameout protection state, the following is also included: If the engine speed reaches the fourth speed threshold, the engine's effective torque is greater than the torque threshold, the gear is in a forward gear, the vehicle speed is greater than the vehicle speed threshold, and the absolute value of the difference between the engine speed and the transmission input shaft speed is less than the fifth speed threshold and the duration is the third time threshold; Then clear the flag bit and control the automatic transmission to exit the engine shutdown protection mode.

7. An electronic device, characterized in that, It includes at least one processor and a memory communicatively connected to the at least one processor; The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the automatic transmission control method according to any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that cause a processor to execute the automatic transmission control method according to any one of claims 1-5.

Images