Engine intelligent idling control system and method

[0037] Example

[0038] See figure 1 , Which is a block diagram of the intelligent idle speed control system of the engine of the present invention. Such as figure 1 As shown, the intelligent engine idle control system of the present invention includes an engine speed sensor, an accelerator pedal position sensor, a brake pedal position sensor, an electronic stability controller, a gear position sensor, a transmission controller, and an engine controller.

[0039] The engine speed sensor is used to collect the engine idling speed.

[0040] The brake pedal position sensor is used to collect the brake pedal position.

[0041] The accelerator pedal position sensor is used to collect the accelerator pedal position.

[0042] The system also includes a gear position sensor, a wheel speed sensor and an electronic stability control system. The gear position sensor is used to collect the current gear position and the target gear position. The electronic stability control system includes an electronic stability controller, a wheel speed sensor, and a communication unit. The wheel speed sensor is used to collect the wheel speed. The electronic stability controller is used to calculate the real-time vehicle speed according to the wheel speed. Communicate with the transmission controller and the engine controller respectively.

[0043] The electronic stability control system also includes a steering sensor, a side slip sensor, a lateral acceleration sensor, etc., which can monitor the driving state of the vehicle in real time.

[0044] When the vehicle is in coasting mode, the engine controller judges the difference between the engine speed and the current speed of the transmission according to the accelerator pedal position or the brake pedal position information, and controls the actual output torque of the engine according to the speed difference to ensure that the current engine speed and the transmission The input shaft speed is consistent.

[0045] When the vehicle is driving, the brake and accelerator are released at the same time, the vehicle enters the coasting mode, in which the engine is in idle speed control. Generally, there are two ways to exit the coasting mode. One is the low target idle speed and does not change with the gear position. In this idle speed control situation, the driver steps on the accelerator and exits the coasting idle mode momentarily, the engine is at low speed and the transmission input The shaft is at a high speed, and the speed difference between the two is relatively large. Because the speed difference is greater immediately after the coast downshift, in the present invention, when the driver steps on the accelerator, the engine controller controls the engine according to the collected accelerator pedal position information Exit idle speed control. At this time, the engine speed increases. The engine controller determines whether the difference between the current engine speed and the current speed of the transmission is greater than the set value. If so, it controls the actual output torque of the engine to ensure that the current engine speed is higher than the transmission input shaft. The high speed and small speed difference ensure that the torque of the engine to the vehicle during the whole combination process is a positive torque, which solves the problem of transmission frustration. The invention limits the output torque of the engine before the transmission is fully closed by calculating the difference between the engine and the input shaft of the transmission. The difference between the two speeds shows an increasing trend, limits the requested torque of the accelerator pedal of the engine, and solves the problem that the high speed difference causes the power chain to close Long time and clutch wear life issues.

[0046] The other is when the brake exits the coasting condition, in this condition, the gear sensor is used to collect the current gear and target gear of the transmission, and send the current gear and target gear information to the transmission controller. The transmission controller calculates the current speed of the transmission according to the current gear position and the real-time vehicle speed, and the transmission controller also calculates the target speed of the transmission according to the target gear position and the real-time vehicle speed. When the driver steps on the brake pedal, the transmission input shaft speed decreases rapidly at this time, while the engine is still in high idle control. The present invention uses the transmission target speed as the engine target idling speed. When the brake pedal position sensor collects the brake pedal position information, the engine controller pre-adjusts the current engine speed according to the collected brake pedal position information, so that the current engine speed is consistent with the target idling speed of the engine, and the current engine speed is reduced, and then judge Whether the speed difference between the adjusted current engine speed and the transmission current speed is greater than the set value, if the speed difference is greater than the set value, the current idle speed of the engine is controlled by limiting the engine torque to ensure that the current engine speed is lower than the transmission input shaft speed. Make the engine always output negative torque to the whole vehicle, so as to prevent the difference between the two speeds during the clutch closing period from being too large, and to solve the problem of sliding before braking. In the present invention, when the brake exits the coasting mode, the engine target idling speed is adjusted in advance according to the brake pedal angle. The deeper the brake is, the more the target idling speed of the engine is reduced to ensure that the current engine speed is lower than the speed of the transmission input shaft. Make the engine output negative torque to the whole vehicle all the time, and solve the problem of sliding before braking.

[0047] It should be noted that in the present invention, the target speed of the transmission is set as the target idling speed of the engine. When the brake exits coasting, the engine controller pre-adjusts the target idling speed of the engine according to the collected brake pedal position information. The torque request is adjusted by the change of the speed, and the output torque is adjusted to indirectly control the engine speed, so that the current engine speed is consistent with the engine target idle speed.

[0048] When the speed difference between the current speed of the transmission and the current speed of the engine is within the set value, the transmission controller issues a command according to the closed state of the clutch. If the clutch is fully closed, the vehicle exits the coasting mode and ends this idle speed control, otherwise End this idle speed control directly.

[0049] In this embodiment, by collecting the transmission target gear and vehicle speed signals, calculate the target speed of the transmission input shaft after shifting, and use it as the engine target idling speed under coasting idling to ensure the current engine speed and transmission input shaft speed under coasting conditions Synchronize. During acceleration and exit from coasting, the engine torque is limited according to the speed difference between the engine and the input shaft of the transmission to prevent the speed difference between the two during the clutch closing period. When the brake exits the coasting mode, adjust the target idle speed according to the brake pedal to ensure that the engine outputs negative torque during the clutch closing period. And according to the speed difference between the engine and the input shaft of the transmission, the engine speed is limited to prevent the speed difference between the two when the clutch is closed.

[0050] Example

[0051] This embodiment provides an intelligent engine idle speed control method under acceleration and exit coasting conditions, please refer to figure 2 , figure 2 It is a schematic flow diagram of the intelligent idle speed control method of the engine of the present invention. Such as figure 2 As shown, the control method includes the following steps:

[0052] S1. When the vehicle is in coasting mode, use the gear sensor to collect the target gear of the vehicle, and use the electronic stability controller to calculate the real-time vehicle speed.

[0053] S2. The transmission controller calculates the target speed of the transmission according to the target gear of the vehicle and the real-time vehicle speed.

[0054] S3. Use the gear sensor to collect the current gear of the vehicle.

[0055] S4. The transmission controller calculates the current speed of the transmission according to the current gear position and real-time vehicle speed of the vehicle.

[0056] S5. Use the engine speed sensor to collect the current engine speed.

[0057] S6. Use the engine controller to calculate the speed difference between the current speed of the engine and the current speed of the transmission.

[0058] S7. Use the accelerator pedal position sensor to collect accelerator pedal position information.

[0059] S8. Determine whether the accelerator pedal is depressed, and if depressed, go to step S9.

[0060] S9. When the accelerator pedal position information is acquired, the engine controller controls the engine to exit the idle speed control according to the accelerator pedal position information.

[0061] S10. The engine controller determines whether the difference between the current speed of the engine and the current speed of the transmission is greater than a first set value.

[0062] S11. If the speed difference is greater than the first set value, limit the actual output torque of the engine; otherwise, go directly to step S16.

[0063] S16. The transmission controller detects whether the clutch is completely closed and issues a command.

[0064] S17. If the clutch is completely closed, the vehicle exits the coasting mode and ends the engine idle speed control.

[0065] In this embodiment, under coasting conditions, the transmission target gear and vehicle speed signals are collected to predict the change in the rotation speed of the input shaft of the transmission as the target idle speed of the engine. The first is to ensure that the engine and transmission input shaft speed difference is small when exiting the coasting condition, and the engine and transmission speeds are quickly synchronized and combined, which solves the problem of long power chain closure time, especially slow power response under coasting acceleration conditions problem. The second is to use the target gear to calculate the target idle speed. During the coasting shift of the transmission, the engine speed can be adjusted in advance to keep synchronization with the speed of the transmission input shaft after the shift to prevent the speed difference between the two after the coasting shift.

[0066] When accelerating and exiting the coasting mode, before accelerating, the engine speed is close to the speed of the transmission input shaft. After acceleration, the engine speed increases, which can ensure that the engine speed is greater than the transmission input shaft speed and the difference is small, and the torque of the engine to the vehicle during the whole combination process is positive torque, which solves the problem of transmission frustration.

[0067] Calculate the speed difference between the engine and the transmission input shaft to limit the engine output torque before the transmission is fully closed. The speed difference between the two is increasing, limiting the torque requested by the engine's pedal, and solving the problem of long power chain closing time and clutch wear life caused by high speed difference.

[0068] Example

[0069] This embodiment provides an intelligent engine idling control method when the brake is exited from coasting. Please refer to figure 2 , The control method includes the following steps:

[0070] S1. When the vehicle is in coasting mode, use the gear sensor to collect the target gear of the vehicle, and use the electronic stability controller to calculate the real-time vehicle speed.

[0071] S2. The transmission controller calculates the target speed of the transmission according to the target gear of the vehicle and the real-time vehicle speed. The transmission target speed is set as the engine target idle speed.

[0072] S3. Use the gear sensor to collect the current gear of the vehicle.

[0073] S4. The transmission controller calculates the current speed of the transmission according to the current gear position and real-time vehicle speed of the vehicle.

[0074] S5. Use the engine speed sensor to collect the current engine speed.

[0075] S6. Use the engine controller to calculate the speed difference between the current speed of the engine and the current speed of the transmission.

[0076] S7. Use the accelerator pedal position sensor to collect accelerator pedal position information.

[0077] S8. Determine whether the accelerator pedal is depressed. If the accelerator pedal is not depressed, go to step S12.

[0078] S12. When the accelerator pedal position information is not obtained, use the brake pedal position sensor to collect the brake pedal position information.

[0079] S13. If the brake pedal position information is collected, the engine controller pre-adjusts the current engine speed to make it consistent with the engine target idling speed. During the clutch closing period, ensure that the engine speed is lower than the speed of the transmission input shaft, so that the engine always outputs negative torque to the vehicle. If the brake pedal position information is not collected, step S16 is entered.

[0080] S14. The engine controller determines whether the difference between the pre-adjusted current engine speed and the transmission current speed is greater than a second set value.

[0081] S15. If the speed difference is greater than the second set value, limit the engine output torque so as to adjust the current engine speed; otherwise, go directly to step S16.

[0082] S16. The transmission controller detects whether the clutch is completely closed and issues a command.

[0083] S17. If the clutch is completely closed, the vehicle exits the coasting mode and ends the engine idle speed control.

[0084] In this embodiment, when braking exits the coasting mode, the target idle speed is adjusted in advance according to the angle of the brake pedal. The deeper the brake is stepped on, the more the target idling speed is reduced to ensure that the engine speed is lower than the speed of the transmission input shaft, so that the engine always outputs negative torque to the whole vehicle, and solves the problem of sliding before braking. When the speed difference is too large, fine-tune the target idle speed after the brake correction to prevent the excessive speed difference between the two.

[0085] It should be noted that the first setting value and the second setting value in the present invention are the same setting value or different setting values, which can be determined according to actual conditions.

[0086] The intelligent engine idle speed control system and method of the present invention are not only suitable for automatic transmission vehicles, but also suitable for manual transmission vehicles.

[0087] The present invention has the following advantages:

[0088] (1) The intelligent engine idling control system and method of the present invention calculates the target speed of the transmission input shaft after shifting by collecting the transmission target gear and vehicle speed signals, and uses it as the target idling speed at the engine coasting idle speed to ensure the coasting work In this case, the engine and transmission input shaft speeds are synchronized.

[0089] (2) The intelligent engine idle control system and method of the present invention limit the engine torque according to the speed difference between the engine and the transmission input shaft when accelerating and exiting the coasting condition, and prevent the speed difference between the two during the clutch closing period. , To ensure that the torque of the engine to the vehicle during the whole combination process is positive torque, which solves the problem of transmission frustration.

[0090] (3) When the brake exits the coasting condition, adjust the target idle speed according to the brake pedal to ensure that the engine outputs negative torque during the clutch closing period. And according to the speed difference between the engine and the input shaft of the transmission, the engine speed is limited to prevent the speed difference between the two during the clutch closing period from being too large, so that the engine always outputs negative torque to the whole vehicle and solves the problem of sliding before the coasting brake.