Cooperative control method for skid resistance and gear shifting of commercial vehicle

Abstract

The invention discloses a cooperative control method for skid resistance and gear shifting of a commercial vehicle, relates to the technical field of vehicle skid resistance control, and aims to keep the torque limit continuity of an engine and improve the stability and safety performance of the vehicle under complex road conditions by optimizing a cooperative control mechanism of an anti-skid control system ASR and a transmission control unit TCU. The present invention prevents a process in which a gear shifting operation caused by a transmission control unit (TCU) may be interrupted when an anti-slip system (ASR) outputs an engine limit torque to control wheel slip on a low adhesion road surface. The frequent switching of the vehicle between the slipping state and the non-slipping state due to the fluctuation of the driving torque is effectively avoided, and the safety performance and the driving experience are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle anti-skid control, and in particular to a coordinated control method for anti-skid and gear shifting of a commercial vehicle. Background Art

[0002] Anti-Spin Regulation (ASRA) is a vehicle safety technology used to improve a vehicle's handling and stability. When the driver accelerates, turns too quickly, or experiences wheel slip, the ASR system automatically reduces engine torque and independently stops the spinning wheel through the braking system. This helps the vehicle maintain better directional control and stability. The ASR system is primarily used in rainy or muddy conditions to prevent dangerous situations caused by wheel slip. It is a common driver assistance feature in many modern vehicles. The driver's requested torque is ultimately delivered to the wheels after torque management (limitation) by the Transmission Control Unit (TCU) and the Anti-Spin Regulation (ASR) system.

[0003] On low-grip roads, the vehicle may slip. When the anti-skid system (ASR) detects slip, it intervenes to control and stabilize the slip rate to a preset value. However, after the slip is suppressed, if the engine speed reaches the upshift point, the transmission control unit (TCU) will instruct the transmission to shift gears. During the gear shift, because the engine's driving torque is 0, the vehicle's slip state will disappear and the ASR will exit control. However, when the gear shift is completed, the vehicle may enter a slip state again due to the recovery of driving torque, causing the ASR system to re-intervene to adjust the vehicle state. This continuous cycle causes the vehicle to frequently enter and exit the slip state, affecting safety performance and failing to ensure effective control and stability.

[0004] The Chinese patent application number is: 202410812284.8, which involves a method, device, equipment and readable storage medium for controlling a vehicle on a low-adhesion road surface. By restricting the transmission control unit (TCU) from entering a prohibited shifting mode, the vehicle is prevented from slipping again. However, this patent prevents the vehicle from slipping again by restricting the TCU from shifting, that is, the transmission enters a prohibited shifting mode. When the engine is operating in a high-speed zone and the transmission is in a prohibited shifting mode, the vehicle will be in a low-gear and high-speed scenario. At this time, the vehicle's economic performance is very poor, carbon emissions increase, and noise is relatively high. Summary of the Invention

[0005] In order to overcome the deficiencies of the above technologies, the present invention provides a control method for ensuring that the vehicle does not slip after shifting gears by coordinating the control of the transmission control unit TCU and the anti-skid system ASR.

[0006] The technical solution adopted by the present invention to overcome the technical problems is:

[0007] A collaborative control method for anti-skid and gear shifting of a commercial vehicle, comprising:

[0008] S1. The transmission control unit TCU calculates the wheel slip rate S according to the ASREngCtrlActive signal and the transmission control unit TCU. slip Determine whether the transmission control unit (TCU) has entered a slipping state;

[0009] S2. Calculate the corrected shift speed n when the transmission control unit TCU enters the slipping scenario base ';

[0010] S3. When the engine speed reaches the corrected shift speed n base ', the transmission control unit TCU sends a target gear request and enters the gear shift state. At the same time, the transmission control unit TCU calculates the theoretical maximum available torque T of the target gear. sel , the anti-skid control system ASR calculates the engine torque limit T under the target gear ASRsel ; S4 obtains the driver's demand torque, the maximum available engine torque, the driver's demand torque, the maximum available engine torque, the theoretical maximum available torque T sel , engine torque limit T ASRsel The minimum value is taken as the maximum torque T of the target gear Rqed ;

[0011] S5. The transmission control unit TCU takes over the engine control and starts shifting gears, increasing the engine torque to the maximum torque T Rqed ;

[0012] S6. The anti-skid control system ASR takes over control of the engine torque and completes the gear shift.

[0013] Furthermore, step S1 includes the following steps:

[0014] S1-1 transmission control unit TCU receives the ASREngCtrlActive signal value in the EBC1 message;

[0015] S1-2. Transmission control unit TCU by formula Calculate the wheel slip rate S slip , where V whel is the wheel speed measured by the front wheel speed sensor, V vel is the vehicle speed calculated from the transmission output shaft speed;

[0016] S1-3. When the ASREngCtrlActive signal value is 1 and the wheel slip rate S slipWhen the value of ASREngCtrlActive signal is 0 and the wheel slip rate S is greater than the threshold value A, the transmission control unit TCU enters the slip scene. slip When the value is less than the threshold value B, after waiting for the delay time C, the transmission control unit TCU exits the slipping scenario.

[0017] Furthermore, in step S1-2, V vel =2πr*n Outsftspd / i o Calculate the vehicle speed V vel , where r is the tire radius of the vehicle, n Outsftspd is the gearbox output shaft speed, i o is the vehicle's final reduction ratio.

[0018] Furthermore, in step S1-3, threshold A is 4%, threshold B is 2%, and delay time C is 50 ms.

[0019] Furthermore, step S2 includes the following steps:

[0020] S2-1. Through the formula The correction coefficient f is calculated, where a, a′, b, b′, c, c′, d′, k, and k′ are all calibration quantities; S2-2. Through the formula Calculate the shift speed n base ′, where n EngP2 is the engine speed at point P2, n offset is the calibration quantity, n base It is the shift speed of the transmission control unit TCU in normal mode.

[0021] Furthermore, step S3 includes the following steps:

[0022] S3-1. When the engine speed reaches the corrected shift speed, the transmission control unit TCU saves the actual engine torque T when the transmission control unit TCU issues the target gear request. cur ;

[0023] S3-2. Through formula T sel =(T cur *i cur *η cur ) / (i sel *η sel ) Calculate the theoretical maximum available torque T of the target gear sel , where i cur is the gearbox ratio of the current gear, η cur is the transmission efficiency of the current gear, i sel is the gearbox ratio of the target gear, η selThe transmission efficiency of the target gear; S3-3. When the engine speed reaches the corrected shift speed, the anti-slip control system ASR saves the engine torque limit T when the transmission control unit TCU issues a target gear request ASRcur ;

[0024] S3-4. Through formula T ASRsel =(T ASRcur *i cur *η cur ) / (i sel *η sel ) Calculate the engine torque limit T under the target gear ASRsel .

[0025] Furthermore, in step S4 , the transmission control unit TCU obtains the driver demand torque through the DriversDemandEngPercentTorque signal in the message EEC1 , and obtains the maximum available engine torque through the ActmaxAvailEngPercentTorque signal in the message EEC2 .

[0026] The anti-skid control system ASR controls the initial torque of the engine to be the maximum torque of the target gear T after step S6. Rqed .

[0027] Preferably, the calibration quantity a is 0.3, the calibration quantity a′ is 0.39, the calibration quantity b is 1, the calibration quantity b′ is 1, the calibration quantity c is 1, the calibration quantity c′ is 1, the calibration quantity d′ is 50, the calibration quantity k is 2, the calibration quantity k′ is 2, and the calibration quantity n is offset The value is 50rpm.

[0028] The present invention has the beneficial effect of maintaining engine torque limitation continuity by optimizing the coordinated control mechanism between the anti-skid control system (ASR) and the transmission control unit (TCU), improving vehicle stability and safety on complex road conditions. This prevents the transmission control unit (TCU) from interrupting shifting operations when the anti-skid system (ASR) outputs engine torque limitation to control wheel slip on low-adhesion roads. This effectively prevents the vehicle from frequently switching between slipping and non-slipping states due to fluctuations in drive torque, ensuring safety and a superior driving experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a flow chart of the method for determining a slipping scenario by the TCU of the present invention;

[0030] Figure 2 This is a flow chart of the control method in the slip mode of the present invention. DETAILED DESCRIPTION

[0031] The following is combined with Figure 1 , Attachment Figure 2 The present invention is further described.

[0032] A collaborative control method for anti-skid and gear shifting of a commercial vehicle, comprising:

[0033] S1. The transmission control unit TCU calculates the wheel slip rate S according to the ASREngCtrlActive signal and the transmission control unit TCU. slip Determine whether the transmission control unit TCU has entered a slipping state.

[0034] S2.As attached Figure 2 As shown, when the transmission control unit TCU enters the slipping scene, it calculates the corrected shift speed n base ′.

[0035] S3. When the engine speed reaches the corrected shift speed n base ', the transmission control unit TCU sends a target gear request and enters the gear shift state. At the same time, the transmission control unit TCU calculates the theoretical maximum available torque T of the target gear. sel , the anti-skid control system ASR calculates the engine torque limit T under the target gear ASRsel S4. Obtain the driver's required torque and the maximum available engine torque, and convert the driver's required torque, the engine's maximum available torque, and the theoretical maximum available torque T sel , engine torque limit T ASRsel The minimum value is taken as the maximum torque T of the target gear Rqed .

[0036] S5. The transmission control unit (TCU) takes over the engine control and starts shifting gears to prevent the engine from continuously operating in the high speed range and increase the engine torque to the maximum torque T. Rqed .

[0037] S6. The anti-skid control system ASR takes over control of the engine torque and completes the gear shift.

[0038] By optimizing the coordinated control mechanism between the anti-skid control system ASR and the transmission control unit TCU, the continuity of engine torque limit is maintained, improving the vehicle's stability and safety performance under complex road conditions.

[0039] In one embodiment of the present invention, as shown in the attached Figure 1As shown, step S1 includes the following steps: S1-1. The transmission control unit (TCU) receives the ASREngCtrlActive signal value in the EBC1 message. During non-shifting periods, the TCU directly receives and uses the ASREngCtrlActive signal value. During shifting periods, the TCU locks and uses the current ASREngCtrlActive signal value. This prevents the TCU from misleading the TCU's slippage judgment due to the ASREngCtrlActive signal value being equal to zero due to the engine torque being reset to zero and the wheels temporarily no longer slipping.

[0040] S1-2. Transmission control unit TCU by formula Calculate the wheel slip rate S slip , where V whel The wheel speed measured by the wheel speed sensor of the front wheel (non-driving wheel) (from the FrontAxle signal in EBC2), V vel The vehicle speed is calculated from the transmission output shaft speed (from the TachographVehicleSpeed signal in TCO1).

[0041] S1-3. When the ASREngCtrlActive signal value is 1 and the wheel slip rate S slip When the value of ASREngCtrlActive signal is 0 and the wheel slip rate S is greater than the threshold value A, the transmission control unit TCU enters the slip scene. slip When the value is less than the threshold value B, after waiting for the delay time C, the transmission control unit TCU exits the slipping scenario.

[0042] In one embodiment of the present invention, in step S1-2, V vel =2πr*n Outsftspd / i o Calculate the vehicle speed V vel , where r is the tire radius of the vehicle, n Outsftspd is the gearbox output shaft speed, i o is the vehicle's final reduction ratio.

[0043] In one embodiment of the present invention, in step S1-3, threshold A is 4%, threshold B is 2%, and delay time C is 50 ms.

[0044] In one embodiment of the present invention, step S2 includes the following steps:

[0045] S2-1. Through the formula The correction coefficient f is calculated, where a, a′, b, b′, c, c′, d′, k, and k′ are all calibration quantities; S2-2. Through the formula Calculate the shift speed n base ′, where n EngP2 is the engine speed at point P2, n offset is the calibration quantity, n base It is the shift speed of the transmission control unit TCU in normal mode.

[0046] In this embodiment, preferably, the calibration quantity a is 0.3, the calibration quantity a′ is 0.39, the calibration quantity b is 1, the calibration quantity b′ is 1, the calibration quantity c is 1, the calibration quantity c′ is 1, the calibration quantity d′ is 50, the calibration quantity k is 2, the calibration quantity k′ is 2, and the calibration quantity n is 0. offset The value is 50 rpm. In one embodiment of the present invention, step S3 includes the following steps:

[0047] S3-1. When the engine speed reaches the corrected shift speed, the transmission control unit TCU saves the actual engine torque T when the transmission control unit TCU issues the target gear request. cur .

[0048] S3-2. As the vehicle's ground adhesion remains unchanged before and after shifting, the formula T sel =(T cur *i cur *η cur ) / (i sel *η sel ) Calculate the theoretical maximum available torque T of the target gear sel , where i cur is the gearbox ratio of the current gear, η cur is the transmission efficiency of the current gear, i sel is the gearbox ratio of the target gear, η sel is the transmission efficiency of the target gear.

[0049] S3-3. When the engine speed reaches the corrected shift speed, the anti-skid control system ASR saves the engine torque limit T when the transmission control unit TCU issues the target gear request. ASRcur ;

[0050] S3-4. Through formula T ASRsel =(T ASRcur *i cur *η cur ) / (i sel *η sel ) Calculate the engine torque limit T under the target gear ASRsel .

[0051] In one embodiment of the present invention, in step S4, the transmission control unit TCU obtains the driver demand torque through the DriversDemandEngPercentTorque signal in the message EEC1, and the transmission control unit TCU obtains the maximum available engine torque through the ActmaxAvailEngPercentTorque signal in the message EEC2.

[0052] In one embodiment of the present invention, the anti-skid control system ASR controls the initial torque of the engine to be the maximum torque of the target gear T after step S6. Rqed This is to avoid a sudden increase in torque after the gear shift is completed and to ensure that the working state of the anti-skid control system ASR system is consistent before and after the gear shift.

[0053] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for cooperative control of anti-skid and gear shifting of a commercial vehicle, characterized in that: include: S1. The transmission control unit TCU calculates the wheel slip rate S according to the ASREngCtrlActive signal and the transmission control unit TCU. slip Determine whether the transmission control unit (TCU) has entered a slipping state; S2. Calculate the corrected shift speed n when the transmission control unit TCU enters the slipping scenario base '; S3. When the engine speed reaches the corrected shift speed n base ', the transmission control unit TCU sends a target gear request and enters the gear shift state. At the same time, the transmission control unit TCU calculates the theoretical maximum available torque T of the target gear. sel , the anti-skid control system ASR calculates the engine torque limit T under the target gear ASRsel ; S4. Obtain the driver's required torque and the maximum available engine torque, and convert the driver's required torque, the engine's maximum available torque, and the theoretical maximum available torque T sel , engine torque limit T ASRsel The minimum value is taken as the maximum torque T of the target gear Rqed ; S5. The transmission control unit TCU takes over the engine control and starts shifting gears, increasing the engine torque to the maximum torque T Rqed ; S6. The anti-skid control system ASR takes over control of the engine torque and completes the gear shift.

2. The coordinated control method for anti-skid and gear shifting of a commercial vehicle according to claim 1, characterized in that ,Step S1 includes the following steps: S1-1 transmission control unit TCU receives the ASREngCtrlActive signal value in the EBC1 message; S1-2. Transmission control unit TCU by formula Calculate the wheel slip rate S slip , where V whel is the wheel speed measured by the front wheel speed sensor, V vel is the vehicle speed calculated from the transmission output shaft speed; S1-3. When the ASREngCtrlActive signal value is 1 and the wheel slip rate S slip When the value of ASREngCtrlActive signal is 0 and the wheel slip rate S is greater than the threshold value A, the transmission control unit TCU enters the slip scene. slip When the value is less than the threshold value B, after waiting for the delay time C, the transmission control unit TCU exits the slipping scenario.

3. The coordinated control method for anti-skid and gear shifting of a commercial vehicle according to claim 2, characterized in that: In step S1-2, V vel =2πr*n Outsftspd / i o Calculate the vehicle speed V vel , where r is the tire radius of the vehicle, n Outsftspd is the gearbox output shaft speed, i o is the vehicle's final reduction ratio.

4. The coordinated control method for anti-skid and gear shifting of a commercial vehicle according to claim 2, characterized in that: In step S1-3, threshold A is 4%, threshold B is 2%, and delay time C is 50 ms.

5. The coordinated control method for anti-skid and gear shifting of a commercial vehicle according to claim 2, characterized in that: Step S2 includes the following steps: S2-1. Through the formula The correction coefficient f is calculated, where a, a′, b, b′, c, c′, d′, k, and k′ are all calibration quantities; S2-2. Through the formula Calculate the shift speed n base ′, where n EngP2 is the engine speed at point P2, n offset is the calibration quantity, n base It is the shift speed of the transmission control unit TCU in normal mode.

6. The coordinated control method for anti-skid and gear shifting of a commercial vehicle according to claim 1, characterized in that: Step S3 includes the following steps: S3-1. When the engine speed reaches the corrected shift speed, the transmission control unit TCU saves the actual engine torque T when the transmission control unit TCU issues the target gear request. cur ; S3-2. Through formula T sel =(T cur *i cur *η cur ) / (i sel *η sel ) Calculate the theoretical maximum available torque T of the target gear sel , where i cur is the gearbox ratio of the current gear, η cur is the transmission efficiency of the current gear, i sel is the gearbox ratio of the target gear, η sel is the transmission efficiency of the target gear; S3-3. When the engine speed reaches the corrected shift speed, the anti-skid control system ASR saves the engine torque limit T when the transmission control unit TCU issues the target gear request. ASRcur ; S3-4. Through formula T ASRsel =(T ASRcur *i cur *η cur ) / (i sel *η sel ) Calculate the engine torque limit T under the target gear ASRsel .

7. The coordinated control method for anti-skid and gear shifting of a commercial vehicle according to claim 1, characterized in that: In step S4 , the transmission control unit TCU obtains the driver demand torque through the DriversDemandEngPercentTorque signal in the message EEC1 , and obtains the maximum available engine torque through the ActmaxAvailEngPercentTorque signal in the message EEC2 .

8. The coordinated control method for anti-skid and gear shifting of a commercial vehicle according to claim 1, characterized in that: The anti-skid control system ASR controls the initial torque of the engine to be the maximum torque of the target gear T after step S6. Rqed .

9. The method for coordinated control of anti-skid and gear shifting of a commercial vehicle according to claim 5, characterized in that: The calibration quantity a is 0.3, the calibration quantity a′ is 0.39, the calibration quantity b is 1, the calibration quantity b′ is 1, the calibration quantity c is 1, the calibration quantity c′ is 1, the calibration quantity d′ is 50, the calibration quantity k is 2, the calibration quantity k′ is 2, and the calibration quantity n is offset The value is 50rpm.

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