A method and system for automatic gear shifting of a commercial vehicle automatic gear shifting transmission

Abstract

The application provides a shift control method and system for a commercial vehicle automatic shift gearbox, and the method comprises the following steps: obtaining a target vehicle first running state, determining a first up-down shift trigger speed under the target vehicle first running state based on the target vehicle first running state; determining the vehicle first running state's hundred-kilometer power and the first running state gear of the target vehicle first running state by using the vehicle speed of the target vehicle first running state, and determining whether to correct the first running state gear by using the first running state's hundred-kilometer power; correcting the first up-down shift trigger speed to a second up-down shift trigger speed after correcting the first running state gear; obtaining an up-down shift gear state according to the second up-down shift trigger speed and the target gear input shaft speed of the second running state. Based on the method, a shift control system for a commercial vehicle automatic shift gearbox is also provided. The application realizes the reduction of unreasonable shifting when the vehicle is uniformly or deceleratingly running under a small throttle opening.

Description

Technical Field

[0001] This invention belongs to the field of commercial vehicle shift control technology, and specifically relates to a shift control method and system for an automatic shift transmission in a commercial vehicle. Background Technology

[0002] Currently, more than half of commercial vehicles use automatic transmissions, which automatically select the appropriate gear based on road conditions and vehicle status. To adapt to complex road conditions, commercial vehicles are typically equipped with automatic transmissions that have 12 or more gears. This increases the number of gear shifts, resulting in differences in fuel economy.

[0003] Currently, the industry standard for automatic transmissions in commercial vehicles achieves gear shifting by directly calibrating the throttle opening and shift point, without considering economical shifting. This is especially problematic when the vehicle is traveling at a constant speed or decelerating, as economical shifting becomes impossible. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a shift control method and system for an automatic transmission in commercial vehicles, which reduces unreasonable shifting when the vehicle is traveling at a constant speed or decelerating under low throttle conditions.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A shift control method for an automatic transmission in a commercial vehicle includes the following steps:

[0007] Obtain the first operating state of the target vehicle, and determine the first upshift / downshift trigger speed based on the first operating state of the target vehicle.

[0008] The speed of the target vehicle in its first operating state is used to determine the power per 100 kilometers and the gear in the first operating state. The power per 100 kilometers in the first operating state is used to determine whether the gear in the first operating state should be corrected.

[0009] After correcting the gear position in the first operating state, the trigger speed for shifting gears in the first shifting gear is corrected to the trigger speed for shifting gears in the second shifting gear; based on the trigger speed for shifting gears in the second shifting gear and the target gear input shaft speed in the second operating state, the shifting gear state is obtained.

[0010] Furthermore, obtaining the first operating state of the target vehicle includes the throttle opening, rotational speed, torque, vehicle speed, and vehicle acceleration of the target vehicle.

[0011] Furthermore, the process of determining vehicle acceleration includes:

[0012] Vehicle acceleration = (current speed - previous speed) / time interval.

[0013] Furthermore, the process of determining the first gear shift trigger speed based on the first operating state of the target vehicle includes:

[0014] The gear shifting is controlled based on the preset relationship between the ABS vehicle speed signal and the throttle opening.

[0015] The first shift point trigger speed when shifting gears.

[0016] Furthermore, the process of determining the power per 100 kilometers of the target vehicle in its first operating state using its speed includes:

[0017] W = P × 100 / v;

[0018] Where W is the power per 100 kilometers; P is the power in the first operating state; and v is the vehicle speed in the first operating state.

[0019] P = n × N / 9550;

[0020] Where n is the rotational speed in the first operating state, and N is the torque in the first operating state.

[0021] Furthermore, the process of determining whether to adjust the gear in the first operating state based on the power per 100 kilometers in the first operating state includes:

[0022] When the throttle opening is less than the preset opening threshold, the first operating state gear is corrected.

[0023] Furthermore, the process of correcting the first operating gear when the throttle opening is less than a preset threshold includes:

[0024] When the acceleration in the first operating state is less than the first acceleration preset threshold, a downshift delay time is set. During the downshift delay time, if the work done at the current moment is less than the work done at the preset shift point, the downshift triggers the speed correction to the set value.

[0025] When the acceleration in the first operating state is greater than or equal to the first preset acceleration threshold and less than the second preset acceleration threshold, and the throttle opening is kept less than the preset opening threshold before and after the gear shift, and the work done at the moment of the first operating state is less than the work done at the preset gear shift point, a downshift correction is performed; wherein, the second preset acceleration threshold is greater than the first preset acceleration threshold.

[0026] Furthermore, the method also includes: not making corrections when the throttle opening is not less than a preset opening threshold.

[0027] Furthermore, the method operates within the TCU module.

[0028] The present invention also proposes a shift control system for an automatic transmission for commercial vehicles, including a preprocessing module, a correction module and a control module;

[0029] The preprocessing module is used to obtain the first operating state of the target vehicle and determine the first upshift / downshift trigger speed based on the first operating state of the target vehicle.

[0030] The correction module is used to determine the power per 100 kilometers and the gear of the first operating state of the target vehicle using the vehicle speed of the first operating state, and to determine whether to correct the gear of the first operating state using the power per 100 kilometers of the first operating state.

[0031] The control module is used to correct the first shifting gear trigger speed to the second shifting gear trigger speed after correcting the first operating state gear; and to obtain the shifting gear state based on the second shifting gear trigger speed and the target gear input shaft speed of the second operating state.

[0032] The effects described in the invention are merely those of the embodiments, and not all the effects of the invention. One of the above technical solutions has the following advantages or beneficial effects:

[0033] This invention proposes a shift control method and system for an automatic transmission in commercial vehicles. The method includes the following steps: acquiring a first operating state of the target vehicle; determining a first upshift / downshift trigger speed based on the first operating state; determining the power per 100 km / h and the gear position of the first operating state using the vehicle speed; determining whether to correct the gear position using the power per 100 km / h of the first operating state; after correcting the gear position, correcting the first upshift / downshift trigger speed to a second upshift / downshift trigger speed; and obtaining the upshift / downshift state based on the second upshift / downshift trigger speed and the target gear input shaft speed of the second operating state. Based on this shift control method for an automatic transmission in commercial vehicles, a shift control system for the same transmission is also proposed. This invention calculates vehicle acceleration based on vehicle speed and determines the impact of power on the shift speed based on vehicle speed, torque, and vehicle speed. Through calculation and judgment, it determines whether to correct the upshift / downshift trigger speed. Adjusting the upshift / downshift trigger speed can achieve economical shifting in the high gear range, reduce the number of shifts and improve fuel economy, while also improving the lifespan of the shift actuator to some extent. Attached Figure Description

[0034] Figure 1 This is a flowchart of a shift control method for an automatic transmission in a commercial vehicle, as proposed in Embodiment 1 of the present invention.

[0035] Figure 2This is a schematic diagram of the control logic of the economic shift control method for automatic transmissions in commercial vehicles proposed in Embodiment 1 of the present invention;

[0036] Figure 3 This is a schematic diagram of a shift control system for an automatic transmission for commercial vehicles, as proposed in Embodiment 3 of the present invention. Detailed Implementation

[0037] To clearly illustrate the technical features of this solution, the invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings. The following disclosure provides many different embodiments or examples for implementing different structures of the invention. To simplify the disclosure of the invention, components and arrangements of specific examples are described below. Furthermore, reference numerals and / or letters may be repeated in different examples. This repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. It should be noted that the components illustrated in the drawings are not necessarily drawn to scale. Descriptions of well-known components, processing techniques, and processes are omitted in this invention to avoid unnecessarily limiting the invention.

[0038] Example 1

[0039] Embodiment 1 of this invention proposes a shift control method for an automatic transmission in commercial vehicles, which reduces unreasonable shifting when the vehicle is traveling at a constant speed or decelerating under low throttle opening conditions, thus solving the technical problem of poor fuel economy in certain operating scenarios.

[0040] Figure 1 This is a flowchart of a shift control method for an automatic transmission in a commercial vehicle, as proposed in Embodiment 1 of the present invention.

[0041] In step S1, the first operating state of the target vehicle is obtained, and the first gear shift trigger speed in the first operating state of the target vehicle is determined based on the first operating state of the target vehicle.

[0042] The target vehicle's initial operating state includes the target vehicle's throttle opening, engine speed, torque, vehicle speed, and vehicle acceleration.

[0043] In this application, the TCU module determines the first gear shift trigger speed in the first operating state of the vehicle based on the ABS vehicle speed signal and throttle opening.

[0044] In this application, the gear shifting is controlled based on a preset relationship between the ABS vehicle speed signal and the throttle opening; the first gear shifting trigger speed is obtained when shifting gears.

[0045] Vehicle acceleration is calculated and filtered based on the ABS vehicle speed signal to obtain the acceleration value.

[0046] The process of determining vehicle acceleration includes:

[0047] Vehicle acceleration = (current speed - previous speed) / time interval.

[0048] The trigger speed for the first upshift or downshift is the actual or set value at the previous basic shift line that has just been crossed.

[0049] In step S2, the power per 100 kilometers and the gear of the first operating state of the target vehicle are determined by the vehicle speed of the first operating state, and the power per 100 kilometers of the first operating state is used to determine whether the gear of the first operating state should be corrected.

[0050] Figure 2 This is a schematic diagram of the control logic of the economic shift control method for automatic transmissions in commercial vehicles proposed in Embodiment 1 of the present invention;

[0051] This application: The process of determining the power per 100 kilometers of the target vehicle in its first operating state using the vehicle speed includes:

[0052] W = P × 100 / v;

[0053] Where W is the power per 100 kilometers; P is the power in the first operating state; and v is the vehicle speed in the first operating state.

[0054] P = n × N / 9550;

[0055] Where n is the rotational speed in the first operating state, and N is the torque in the first operating state.

[0056] The process of determining whether to adjust the gear for the first operating state based on the power per 100 kilometers in the first operating state includes:

[0057] When the throttle opening is less than the preset threshold, the first operating state gear is corrected; when the throttle opening is less than the preset threshold, it is defined as a small throttle state, and correction is only performed in the small throttle state, otherwise no correction is performed;

[0058] When the acceleration in the first operating state is less than or equal to the first acceleration preset threshold, it is in a deceleration state;

[0059] When the acceleration in the first operating state is less than the first acceleration preset threshold, and the throttle is kept low, a downshift delay time is set. During the downshift delay time, if the work done at the current moment is less than the work done at the preset shift point, the downshift triggers the speed correction to the set value.

[0060] If you cannot maintain a low throttle position, it may indicate a need for power due to slowing down while climbing a hill.

[0061] A uniform speed state is defined when the acceleration of the first running state is greater than or equal to a first preset acceleration threshold and less than a second preset acceleration threshold, wherein the second preset acceleration threshold is greater than the first preset acceleration threshold.

[0062] When the acceleration in the first operating state is greater than or equal to the first acceleration preset threshold and less than the second acceleration preset threshold, and the throttle opening is kept less than the preset opening threshold before and after the gear shift, and the work done at the moment of the first operating state is less than the work done at the preset gear shift point, a downshift correction is performed to achieve more economical operation.

[0063] If the driver cannot maintain a low throttle position after shifting gears, it will be difficult to control the vehicle.

[0064] When the acceleration of the first running state is greater than a preset threshold for the second acceleration, it is defined as an acceleration state;

[0065] During acceleration, the vehicle primarily demands power and does not make any fuel economy adjustments.

[0066] When the vehicle is in a low gear range, it mainly operates in the acceleration range. The vehicle shifts gears according to the first upshift / downshift trigger speed, and the TCU module does not perform corrective shifting.

[0067] Taking a 16-speed transmission as an example, the low gear range refers to 1-2-3-4-5-6-7-8-9-10.

[0068] The feature of this invention for achieving economical gear shifting is: by innovatively setting the parameter of power per 100 kilometers, estimating and comparing the parameter before and after gear shifting, and if the condition is met, it indicates that the operation is more economical after correction, and then implementing delayed downshift correction.

[0069] In step S3, after correcting the gear position of the first operating state, the trigger speed for the first upshift / downshift is corrected to the trigger speed for the second upshift / downshift.

[0070] The determination of the trigger speed for the second upshift / downshift must also take into account that the speed after the shift is within the preset optimal speed range.

[0071] In step S4, the shifting gear state is obtained based on the second shifting trigger speed and the target gear input shaft speed of the second operating state.

[0072] The shift control method for an automatic transmission in a commercial vehicle proposed in this application requires hardware modules including: accelerator pedal, TCU module, transmission hardware module, ABS control unit, and engine control unit, etc.

[0073] The TCU module communicates with the ABS control unit, engine control unit, etc., via the CAN bus. The TCU module calculates the basic upshift trigger speed based on the vehicle's operating status; it also calculates a correction coefficient for the upshift trigger speed based on the vehicle's power per 100 km / h, acceleration, and gear position; and then calculates the final upshift / downshift trigger speed based on the correction coefficient. The upshift / downshift status is obtained based on the target gear input shaft speed.

[0074] Embodiment 1 of this invention proposes a shift control method for an automatic transmission in a commercial vehicle. The method calculates the vehicle acceleration based on the vehicle speed and determines the influence of work done on the shift speed based on the vehicle speed, torque, and vehicle speed. The method then calculates and judges to correct the shift trigger speed. Adjusting the shift trigger speed can achieve economical shifting in the high gear range of the vehicle, reduce the number of shifts and improve fuel economy, and at the same time, it can improve the life of the shift actuator to a certain extent.

[0075] The present invention provides a shift control method for an automatic transmission for commercial vehicles, which reduces unreasonable shifting when the vehicle is traveling at a constant speed or decelerating at a small throttle opening.

[0076] Example 2

[0077] Based on the shift control method for an automatic transmission in a commercial vehicle proposed in Embodiment 1 of the present invention, Embodiment 2 of the present invention proposes a shift control system for an automatic transmission in a commercial vehicle. Figure 3 This is a schematic diagram of a shift control system for an automatic transmission in a commercial vehicle according to Embodiment 3 of the present invention. The system also includes a preprocessing module, a correction module, and a control module.

[0078] The preprocessing module is used to obtain the first operating state of the target vehicle and determine the first upshift / downshift trigger speed based on the first operating state of the target vehicle.

[0079] The target vehicle's initial operating state includes the target vehicle's throttle opening, engine speed, torque, vehicle speed, and vehicle acceleration.

[0080] In the preprocessing module, the TCU module in this application determines the first gear shift trigger speed in the first operating state of the vehicle based on the ABS vehicle speed signal and throttle opening.

[0081] In this application, the gear shifting is controlled based on a preset relationship between the ABS vehicle speed signal and the throttle opening; the first gear shifting trigger speed is obtained when shifting gears.

[0082] Vehicle acceleration is calculated and filtered based on the ABS vehicle speed signal to obtain the acceleration value.

[0083] The process of determining vehicle acceleration includes:

[0084] Vehicle acceleration = (current speed - previous speed) / time interval.

[0085] The trigger speed for the first upshift or downshift is the actual or set value at the previous basic shift line that has just been crossed.

[0086] The correction module is used to determine the power per 100 kilometers and the gear of the first operating state of the target vehicle using the vehicle speed of the first operating state, and to determine whether to correct the gear of the first operating state using the power per 100 kilometers of the first operating state.

[0087] The process of the correction module includes: determining the power per 100 kilometers of the target vehicle in its first operating state using the vehicle speed; the process of determining the power per 100 kilometers of the target vehicle in its first operating state includes:

[0088] W = P × 100 / v;

[0089] Where W is the power per 100 kilometers; P is the power in the first operating state; and v is the vehicle speed in the first operating state.

[0090] P = n × N / 9550;

[0091] Where n is the rotational speed in the first operating state, and N is the torque in the first operating state.

[0092] The process of determining whether to adjust the gear for the first operating state based on the power per 100 kilometers in the first operating state includes:

[0093] When the throttle opening is less than the preset threshold, the first operating state gear is corrected; when the throttle opening is less than the preset threshold, it is defined as a small throttle state, and correction is only performed in the small throttle state, otherwise no correction is performed;

[0094] When the acceleration in the first operating state is less than or equal to the first acceleration preset threshold, it is in a deceleration state;

[0095] When the acceleration in the first operating state is less than the first acceleration preset threshold, and the throttle is kept low, a downshift delay time is set. During the downshift delay time, if the work done at the current moment is less than the work done at the preset shift point, the downshift triggers the speed correction to the set value.

[0096] If you cannot maintain a low throttle position, it may indicate a need for power due to slowing down while climbing a hill.

[0097] A uniform speed state is defined when the acceleration of the first running state is greater than or equal to a first preset acceleration threshold and less than a second preset acceleration threshold, wherein the second preset acceleration threshold is greater than the first preset acceleration threshold.

[0098] When the acceleration in the first operating state is greater than or equal to the first acceleration preset threshold and less than the second acceleration preset threshold, and the throttle opening is kept less than the preset opening threshold before and after the gear shift, and the work done at the moment of the first operating state is less than the work done at the preset gear shift point, a downshift correction is performed to achieve more economical operation.

[0099] If the driver cannot maintain a low throttle position after shifting gears, it will be difficult to control the vehicle.

[0100] When the acceleration of the first running state is greater than a preset threshold for the second acceleration, it is defined as an acceleration state;

[0101] During acceleration, the vehicle primarily demands power and does not make any fuel economy adjustments.

[0102] When the vehicle is in a low gear range, it mainly operates in the acceleration range. The vehicle shifts gears according to the first upshift / downshift trigger speed, and the TCU module does not perform corrective shifting.

[0103] Taking a 16-speed transmission as an example, the low gear range refers to 1-2-3-4-5-6-7-8-9-10.

[0104] The feature of this invention for achieving economical gear shifting is: by innovatively setting the parameter of power per 100 kilometers, estimating and comparing the parameter before and after gear shifting, and if the condition is met, it indicates that the operation is more economical after correction, and then implementing delayed downshift correction.

[0105] The control module is used to correct the first shifting gear trigger speed to the second shifting gear trigger speed after correcting the first operating state gear; and to obtain the shifting gear state based on the second shifting gear trigger speed and the target gear input shaft speed of the second operating state.

[0106] In the control module, the determination of the second gear shift trigger speed must also take into account that the speed after the gear shift is within the preset optimal speed range.

[0107] Embodiment 2 of the present invention proposes a shift control system for an automatic transmission for commercial vehicles. The system calculates vehicle acceleration based on vehicle speed and determines the impact of work done on shift speed based on vehicle speed, torque, and vehicle speed. The system then calculates and determines to correct the shift trigger speed. Adjusting the shift trigger speed can achieve economical shifting in the high gear range of the vehicle, reduce the number of shifts and improve fuel economy, and at the same time, it can improve the life of the shift actuator to a certain extent.

[0108] Embodiment 2 of the present invention proposes a shift control system for an automatic transmission for commercial vehicles, which reduces unreasonable shifting when the vehicle is traveling at a constant speed or decelerating at a small throttle opening.

[0109] The description of the relevant parts of the automatic transmission shift control system for commercial vehicles provided in Embodiment 2 of this application can be found in the detailed description of the corresponding parts of the automatic transmission shift control method for commercial vehicles provided in Embodiment 1 of this application, and will not be repeated here.

[0110] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that the elements inherent in a process, method, article, or apparatus that includes a list of elements are included. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Additionally, portions of the technical solutions provided in the embodiments of this application that are consistent with the implementation principles of corresponding technical solutions in the prior art have not been described in detail to avoid excessive elaboration.

[0111] While specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art can make other modifications or variations based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A shift control method for an automatic transmission in a commercial vehicle, characterized in that, Includes the following steps: Obtain the first operating state of the target vehicle, and determine the first upshift / downshift trigger speed based on the first operating state of the target vehicle. The speed of the target vehicle in its first operating state is used to determine the power per 100 kilometers and the gear in the first operating state. The power per 100 kilometers in the first operating state is used to determine whether the gear in the first operating state should be corrected. The process of determining whether to correct the gear in the first operating state by using the power per 100 kilometers in the first operating state includes: correcting the gear in the first operating state when the throttle opening is less than the preset opening threshold. The process of correcting the gear position in the first operating state when the throttle opening is less than a preset threshold includes: when the acceleration in the first operating state is less than a first preset threshold for acceleration, a downshift delay time is set; during the downshift delay time, if the work done at the current moment is less than the work done at a preset shift point, downshifting triggers a speed correction to a set value; when the acceleration in the first operating state is greater than or equal to the first preset threshold for acceleration and less than a second preset threshold for acceleration, and the throttle opening remains less than the preset threshold for acceleration before and after the shift, and the work done at the moment in the first operating state is less than the work done at the preset shift point, downshifting correction is performed; wherein, the second preset threshold for acceleration is greater than the first preset threshold for acceleration. After correcting the gear position in the first operating state, the trigger speed for shifting gears in the first shifting gear is corrected to the trigger speed for shifting gears in the second shifting gear; based on the trigger speed for shifting gears in the second shifting gear and the target gear input shaft speed in the second operating state, the shifting gear state is obtained.

2. The shift control method for an automatic transmission in a commercial vehicle according to claim 1, characterized in that, The acquisition of the first operating state of the target vehicle includes the throttle opening, rotational speed, torque, vehicle speed, and vehicle acceleration of the target vehicle.

3. The shift control method for an automatic transmission in a commercial vehicle according to claim 2, characterized in that, The process of determining vehicle acceleration includes: Vehicle acceleration = (current speed - previous speed) / time interval.

4. The shift control method for an automatic transmission in a commercial vehicle according to claim 1, characterized in that, The process of determining the first upshift / downshift trigger speed based on the first operating state of the target vehicle includes: The gear shifting is controlled based on the preset relationship between the ABS vehicle speed signal and the throttle opening. The first shift point trigger speed when shifting gears.

5. The shift control method for an automatic transmission in a commercial vehicle according to claim 2, characterized in that, The process of determining the power per 100 kilometers of the target vehicle in its first operating state using its speed includes: W = P × 100 / v; Where W is the power per 100 kilometers; P is the power in the first operating state; and v is the vehicle speed in the first operating state. P = n × N / 9550; Where n is the rotational speed in the first operating state, and N is the torque in the first operating state.

6. The shift control method for an automatic transmission in a commercial vehicle according to claim 1, characterized in that, The method further includes: not making corrections when the throttle opening is not less than a preset opening threshold.

7. A shift control method for an automatic transmission for commercial vehicles according to any one of claims 1 to 6, wherein the method operates in a TCU module.

8. A shift control system for an automatic transmission for commercial vehicles, used to execute the shift control method for an automatic transmission for commercial vehicles as described in any one of claims 1 to 7, characterized in that, It includes a preprocessing module, a correction module, and a control module; The preprocessing module is used to obtain the first operating state of the target vehicle and determine the first upshift / downshift trigger speed based on the first operating state of the target vehicle. The correction module is used to determine the power per 100 kilometers and the gear of the first operating state of the target vehicle using the vehicle speed of the first operating state, and to determine whether to correct the gear of the first operating state using the power per 100 kilometers of the first operating state. The control module is used to correct the first shifting gear trigger speed to the second shifting gear trigger speed after correcting the first operating state gear; and to obtain the shifting gear state based on the second shifting gear trigger speed and the target gear input shaft speed of the second operating state.

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