Shift control method and device of AMT, electronic control unit, medium and product

Abstract

The embodiment of the present application provides a kind of shift control method, device, electronic control unit, medium and product of AMT, the method comprises: obtaining the current throttle opening of vehicle, engine reference torque and the output shaft speed of current AMT;According to the output shaft speed of AMT, the input shaft speed of AMT corresponding to each gear is calculated;The input shaft speed of AMT is input into the engine outer characteristic curve to obtain the corresponding outer characteristic torque;The current throttle opening and the input shaft speed of AMT corresponding to each gear are input into the throttle pedal map to obtain the engine torque corresponding to each gear under the current throttle opening;According to mechanical efficiency and the engine torque corresponding to each gear and outer characteristic torque, the traction and the vehicle resistance under each gear are calculated;The maximum gear greater than the vehicle resistance in the traction under each gear obtained is determined as target gear and the shift of AMT is controlled in the way of not exceeding target gear.The method of the embodiment of the present application can avoid cyclic shift.

Description

Technical Field

[0001] This invention relates to the field of shift control technology, and in particular to a shift control method, device, electronic control unit, medium and product for an automatic transmission (AMT). Background Technology

[0002] In the commercial vehicle market, manual transmissions dominate, while AMT (Automatic Manual Transmission) accounts for a very small percentage, thus AMT has great development potential. However, on incline roads, conventional gear selection methods cannot take into account changes in the vehicle's driving environment and the driver's intentions.

[0003] In the existing technology, when a vehicle enters a slope, if the driving force of the vehicle is greater than the driving resistance of the slope, the vehicle accelerates forward. According to the conventional gear decision method, it will upshift at this time. At this time, the driving resistance of the slope is greater than the driving force after upshifting, and the vehicle speed gradually decreases. According to the conventional gear decision method, the vehicle will downshift again, thus entering a cycle of gear shifting. Summary of the Invention

[0004] This invention provides a shift control method, device, electronic control unit, medium, and product for an automatic manual transmission (AMT) to solve the technical problem of cyclic shifting.

[0005] The first aspect of this invention provides a shift control method for an automatic transmission (AMT), comprising:

[0006] Obtain the vehicle's current throttle opening, engine reference torque, and current AMT output shaft speed;

[0007] Based on the current output shaft speed of the AMT and the gear ratios corresponding to each gear of the AMT, the input shaft speed of the AMT corresponding to each gear is calculated, where the input shaft speed of the AMT corresponding to each gear is equal to the engine speed.

[0008] Input the AMT input shaft speed corresponding to each gear into the pre-calibrated engine external characteristic curve to obtain the engine torque percentage corresponding to each gear; where the engine external characteristic curve is the mapping relationship between the engine torque percentage and engine speed at 100% throttle opening in each gear.

[0009] Based on the engine torque percentage corresponding to each gear and the engine reference torque, the external characteristic torque of the vehicle at the current AMT output shaft speed is calculated for each gear; where the external characteristic torque is the maximum driving torque at 100% throttle opening;

[0010] Input the current throttle opening and the AMT input shaft speed corresponding to each gear into the pre-calibrated throttle pedal map to obtain the engine torque corresponding to each gear under the current throttle opening. The throttle pedal map is a mapping relationship between the engine torque under each gear and the engine speed and throttle size.

[0011] Obtain the mechanical efficiency of the engine's powertrain, and calculate the vehicle's traction force in each gear based on the mechanical efficiency, the external characteristic torque corresponding to each gear at the current AMT output shaft speed, and the engine torque corresponding to each gear at the current throttle opening.

[0012] Obtain multiple operating parameters of the vehicle and determine the overall vehicle resistance based on these parameters;

[0013] The gear with the highest calculated traction force that is greater than the overall vehicle resistance is determined as the first target gear.

[0014] When the vehicle enters a slope, control the AMT to shift gears in a manner that does not exceed the first target gear.

[0015] Optionally, after determining the gear with the highest calculated traction force exceeding the vehicle's resistance as the first target gear, the process further includes: obtaining the vehicle's total weight and the gradient of the sloping road section; inputting the total weight and gradient into a pre-calibrated gear map to obtain the vehicle's starting gear under the given total weight and gradient, where the gear map represents the mapping relationship between the vehicle's starting gear and changes in the vehicle's total weight and gradient; if the first target gear is lower than the starting gear, then the starting gear is determined as the second target gear; and controlling the AMT's gear shifting in a manner that does not exceed the second target gear when the vehicle enters the sloping road section.

[0016] Optionally, after determining the gear with the largest traction force among the calculated gears that is greater than the overall vehicle resistance as the first target gear, the process further includes: obtaining the maximum gear that exceeds the weight limit; if the first target gear is greater than the maximum gear that exceeds the weight limit, then determining the maximum gear that exceeds the weight limit as the third target gear; and controlling the AMT's gear shifting in a manner that does not exceed the third target gear when the vehicle enters a slope section.

[0017] Optionally, based on the engine torque percentage corresponding to each gear and the engine reference torque, the external characteristic torque corresponding to each gear at the current AMT output shaft speed is calculated using the following formula:

[0018] T tq1 =θ T *T ref

[0019] In the formula, T tg1 θ represents the external characteristic torque corresponding to each gear.T θ represents the percentage of engine torque corresponding to each gear. T Values ​​range from 0% to 100%, T ref This is the engine's reference torque.

[0020] Optionally, the formula for calculating the traction force of the vehicle in each gear is:

[0021]

[0022] In the formula, F T T represents the traction force corresponding to any gear. tq1 T represents the engine's external characteristic torque for any gear. tq2 T represents the engine torque corresponding to any gear. tq2 ′ represents the engine torque corresponding to upshifting from any gear, i g i represents the gear ratios corresponding to each gear in an AMT (Automated Manual Transmission). o η is the final drive ratio of the vehicle, η is the mechanical efficiency, and r is the tire rolling radius of the vehicle.

[0023] Optionally, the multiple operating parameters include the vehicle's total weight, vehicle speed, rolling resistance coefficient, and gradient; correspondingly, the formula for determining the vehicle's overall resistance based on these multiple operating parameters is:

[0024]

[0025] In the formula, F R Let m be the total vehicle resistance, g be the acceleration due to gravity, f be the rolling resistance coefficient, θ be the slope, and C be the total vehicle weight. D Where A is the air resistance coefficient and U is the frontal area. a Let be the vehicle's speed, and 'a' be the acceleration obtained by inputting the current throttle opening into the acceleration curve, where the acceleration curve is a mapping relationship between the vehicle's acceleration and the throttle opening.

[0026] A second aspect of the present invention provides a shift control device for an automatic transmission (AMT), comprising:

[0027] The parameter acquisition module is used to acquire the vehicle's current throttle opening, engine reference torque, and current AMT output shaft speed.

[0028] The input shaft speed acquisition module is used to calculate the input shaft speed of the AMT for each gear based on the current output shaft speed of the AMT and the speed ratio corresponding to each gear of the AMT. The input shaft speed of the AMT for each gear is equal to the engine speed.

[0029] The engine torque percentage acquisition module is used to input the input shaft speed of the AMT corresponding to each gear into the pre-calibrated engine external characteristic curve to obtain the engine torque percentage corresponding to each gear; wherein the engine external characteristic curve is the mapping relationship between the engine torque percentage and the engine speed at 100% throttle opening in each gear.

[0030] The external characteristic torque calculation module is used to calculate the external characteristic torque of the vehicle at the current AMT output shaft speed based on the engine torque percentage and engine reference torque corresponding to each gear; where the external characteristic torque is the maximum driving torque at 100% throttle opening;

[0031] The engine torque acquisition module is used to input the current throttle opening and the AMT input shaft speed corresponding to each gear into the pre-calibrated throttle pedal map to obtain the engine torque corresponding to each gear under the current throttle opening. The throttle pedal map is a mapping relationship between the engine torque under each gear and the engine speed and throttle size.

[0032] The gear traction calculation module is used to obtain the mechanical efficiency of the engine's powertrain, and calculate the vehicle's traction force in each gear based on the mechanical efficiency, the external characteristic torque corresponding to each gear at the current AMT output shaft speed, and the engine torque corresponding to each gear at the current throttle opening.

[0033] The vehicle resistance calculation module is used to obtain multiple operating parameters of the vehicle and determine the vehicle resistance based on these parameters.

[0034] The first target gear determination module is used to determine the gear with the largest traction force among the calculated gears that is greater than the overall vehicle resistance as the first target gear;

[0035] The control module is used to control the AMT's gear shifting when the vehicle enters a slope section, in a manner that does not exceed the first target gear.

[0036] A third aspect of the present invention provides an electronic control unit for an AMT, comprising: a memory and a processor;

[0037] The memory stores the instructions that the computer executes;

[0038] The processor executes computer-executed instructions stored in memory to implement the shift control method of the AMT in any of the first aspects.

[0039] A fourth aspect of the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the shift control method of an AMT according to any one of the first aspects.

[0040] A fifth aspect of the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the shift control method of AMT according to any one of the first aspects.

[0041] This invention provides an AMT (Automated Manual Transmission) shift control method, device, electronic control unit, medium, and product. By acquiring the engine torque of different gears at the current throttle opening and the engine external characteristic torque corresponding to different gears at 100% throttle opening, the traction force of the vehicle at different gears at the current throttle opening is calculated in real time. The difference between the traction force corresponding to different gears and the vehicle's overall resistance is calculated. The gear with the largest difference greater than zero is determined as the first target gear. The AMT shifting is controlled in a manner that does not exceed the first target gear, which can avoid cyclic shifting, thereby greatly improving the reliability and safety of AMT vehicles. Attached Figure Description

[0042] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0043] Figure 1 A schematic diagram illustrating the principle of cyclic gear shifting when a certain tractor is driving on a slope;

[0044] Figure 2 A schematic flowchart of the shift control method for AMT provided by the present invention;

[0045] Figure 3-1 This is a schematic diagram illustrating the principle of the calculation process of vehicle traction force in different gears provided by the present invention.

[0046] Figure 3-2 This is a schematic diagram illustrating the principle of calculating the maximum gear at the current throttle opening, as provided by the present invention.

[0047] Figure 4 A schematic diagram of the shift control device for an AMT provided by the present invention;

[0048] Figure 5 This is a schematic diagram of the electronic control unit of the AMT provided by the present invention.

[0049] The accompanying drawings have illustrated specific embodiments of the invention, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0050] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.

[0051] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of the present invention will now be described with reference to the accompanying drawings.

[0052] Terminology Explanation:

[0053] AMT: Mechanical automatic transmission is an automatic transmission system consisting of a traditional dry friction plate clutch and manual gearbox, plus an electronic control unit and a gear selection and clutch actuator. Automatic gear selection is achieved by the gear selection actuator, and automatic clutch engagement and disengagement is achieved by the clutch actuator.

[0054] TCU: Transmission Control Unit.

[0055] Engine external characteristic curve: When the throttle opening is 100%, the functional relationship between the engine torque percentage and the engine speed is represented by a curve, which is called the engine external characteristic curve.

[0056] To clearly understand the technical solution of this application, the existing technology solutions will first be described in detail. In the commercial vehicle market, manual transmissions account for the vast majority, while automated manual transmissions (AMTs) account for a very small percentage; therefore, AMTs have significant development potential. However, conventional gear selection methods typically cannot take into account changes in the vehicle's driving environment and the driver's intentions, and cannot adapt to the constantly changing vehicle conditions, road conditions, and driver intentions. In existing technologies, conventional gear selection methods are based on the upshift speed and the target upshift speed. Upshifting is triggered when the transmission input shaft speed, calculated from the output shaft speed, is greater than the upshift speed. The maximum gear at which the upshifted speed exceeds the target upshift speed is determined as the target gear.

[0057] Figure 1 This is a schematic diagram illustrating the principle of cyclic gear shifting when a tractor-trailer is traveling on an incline. (Example:) Figure 1As shown, A, B, C, and D represent the upshift and downshift points for 7th gear and 8th gear respectively, when the throttle opening is α. When the tractor enters the slope, it initially travels in 7th gear at throttle opening α. At this point, the traction force of 7th gear is greater than the slope's resistance, causing the tractor to accelerate. Upon reaching point A, according to the conventional gear selection method, it will upshift to 8th gear, as shown at point B. At this point, the slope's resistance is greater than the traction force of 8th gear at throttle opening α, causing the tractor's speed to slowly decrease until point C, the downshift point to 8th gear. Following the conventional gear selection method, the tractor will automatically downshift to 7th gear, as shown at point D. Since the traction force of 7th gear at throttle opening α is again greater than the slope's resistance, the tractor accelerates back to point A, thus entering a cyclical gear shifting situation.

[0058] Therefore, addressing the technical problem in existing technologies where vehicles easily enter cyclic shifting when operating on slopes using conventional gear selection methods, the inventors discovered a solution. First, they obtained the engine torque for different gears at the current throttle opening and the engine's external characteristic torque for different gears at 100% throttle opening. They then calculated the traction force corresponding to different gears at the current throttle opening in real time. By calculating the difference between the traction force and the vehicle's overall resistance at different gears, they selected the gear with the largest difference (greater than zero) as the target gear for the current throttle opening where traction force exceeds resistance. If the calculated maximum gear is greater than the vehicle's current gear, the AMT shifting is controlled to not exceed the maximum gear, thus overcoming the cyclic shifting problem.

[0059] The embodiments of the present invention will now be described with reference to the accompanying drawings.

[0060] Figure 2 The flowchart of the shift control method for AMT provided by the present invention is shown below. Figure 2 As shown, in this embodiment, the execution subject of the present invention is the electronic control unit of the AMT. When the electronic control unit of the AMT detects that the vehicle has entered a slope section, it performs the following steps:

[0061] S201: Obtain the vehicle's current throttle opening, engine reference torque, and current AMT output shaft speed.

[0062] Specifically, the AMT's electronic control unit collects the vehicle's current throttle opening, engine reference torque, and the current AMT output shaft speed through various sensors on the vehicle.

[0063] S202: Based on the current output shaft speed of the AMT and the speed ratio corresponding to each gear of the AMT, calculate the input shaft speed of the AMT for each gear, where the input shaft speed of the AMT for each gear is equal to the engine speed.

[0064] The speed ratio of an AMT (Automated Manual Transmission) is used to describe the transmission ratio of different gears in an AMT, which refers to the speed ratio between the input shaft speed and the output shaft speed.

[0065] Specifically, when the clutch is engaged, the engine speed is equivalent to the input shaft speed of the AMT, and the output shaft speed of the AMT is equivalent to the current vehicle speed. Based on the gear ratios and output shaft speeds of the AMT in different gears, the corresponding input shaft speeds of the AMT in different gears, i.e., the engine speeds in different gears, can be calculated.

[0066] S203: Input the AMT input shaft speed corresponding to each gear into the pre-calibrated engine external characteristic curve to obtain the engine torque percentage corresponding to each gear; where the engine external characteristic curve is the mapping relationship between the engine torque percentage corresponding to each gear at 100% throttle opening and the engine speed.

[0067] The engine external characteristic curve represents the functional relationship between the engine torque percentage and engine speed when the throttle opening is 100%. Engine torque percentage indicates the percentage of torque produced by the engine at a specific speed relative to its maximum torque.

[0068] Specifically, the calibration method for the engine external characteristic curve can be as follows: On an engine test bench, fix the engine speed and set the throttle opening to 100%. Measure the torque through the engine test bench's data acquisition system. Calculate the ratio of the torque to the engine's maximum torque to obtain the torque percentage at a fixed engine speed. The correspondence between the engine speed matrix composed of different engine speeds and the engine torque percentage matrix composed of different engine torque percentages under 100% throttle opening is represented by a curve, thus obtaining the engine external characteristic curve.

[0069] S204: Based on the engine torque percentage and engine reference torque corresponding to each gear, calculate the external characteristic torque of the vehicle at the current AMT output shaft speed for each gear; where the external characteristic torque is the maximum driving torque at 100% throttle opening.

[0070] In this process, the AMT's electronic control unit sends an engine reference torque acquisition command to the engine's electronic control unit. Based on the current engine speed and current engine torque, the engine's electronic control unit can obtain a definite engine reference torque and send the engine reference torque to the AMT's electronic control unit.

[0071] Specifically, the formula for calculating the external characteristic torque corresponding to each gear at the current AMT output shaft speed is as follows:

[0072] T tq1 =θT *T ref

[0073] In the formula, T tq1 θ represents the external characteristic torque corresponding to each gear. T θ represents the percentage of engine torque corresponding to each gear. T Values ​​range from 0% to 100%, T ref This is the engine's reference torque.

[0074] S205: Input the current throttle opening and the AMT input shaft speed corresponding to each gear into the pre-calibrated throttle pedal map to obtain the engine torque corresponding to each gear under the current throttle opening. The throttle pedal map is a mapping relationship between the engine torque under each gear and the changes in engine speed and throttle size.

[0075] The accelerator pedal map represents the mapping relationship between engine speed, accelerator pedal opening, and engine torque. The engine torque corresponding to each gear can be converted into the engine torque corresponding to different engine speeds.

[0076] Specifically, the calibration method for the pre-calibrated throttle pedal map can be as follows: On an engine test bench, set the throttle opening to 20% and fix the engine speed. The torque measured by the engine test bench's data acquisition system will yield the engine torque at a fixed engine speed and 20% throttle opening. By setting different engine speeds, the mapping relationship between the engine speed matrix (composed of different engine speeds) and the engine torque matrix (composed of different engine torques) can be obtained at a 20% throttle opening. Similarly, setting different throttle openings, such as 40%, 60%, 80%, and 100%, will yield the pre-calibrated throttle pedal map.

[0077] S206: Obtain the mechanical efficiency of the engine's powertrain, and calculate the vehicle's traction force in each gear based on the mechanical efficiency, the external characteristic torque corresponding to each gear at the current AMT output shaft speed, and the engine torque corresponding to each gear at the current throttle opening.

[0078] Specifically, engine speed and engine torque are input into the mechanical efficiency map to obtain the mechanical efficiency of the powertrain at the current engine speed and engine torque. The mechanical efficiency map represents the mapping relationship between the mechanical efficiency of the powertrain and changes in engine speed and engine torque. Based on the mechanical efficiency, the external characteristic torque corresponding to each gear at the current AMT output shaft speed, and the engine torque corresponding to each gear at the current throttle opening, the traction force of the vehicle in each gear is calculated using the following formula:

[0079]

[0080] In the formula, F T T represents the traction force corresponding to any gear. tq1 T represents the engine's external characteristic torque for any gear. tq2 T represents the engine torque corresponding to any gear. tq2 ′ represents the engine torque corresponding to upshifting from any gear, i g i represents the gear ratios corresponding to each gear in an AMT (Automated Manual Transmission). o η is the final drive ratio of the vehicle, η is the mechanical efficiency, and r is the tire rolling radius of the vehicle.

[0081] For example, Figure 3-1 This is a schematic diagram illustrating the principle of calculating the traction force of a vehicle in different gears, as provided by the present invention. Figure 3-1 As shown, this calculation assumes the vehicle's traction force in 8th gear. First, based on the current AMT output shaft speed, the AMT input shaft speed for each gear is calculated. The AMT input shaft speed is then input into the engine external characteristic curve, calibrated according to the engine speed matrix and engine torque percentage matrix, to obtain the engine torque percentage for each gear. Finally, the engine torque percentage for each gear is compared with the engine reference torque T for different gears. ref Multiply by each gear to obtain the engine external characteristic torque T for each gear. tq1 The AMT's input shaft speed is input into a throttle pedal map calibrated based on the engine speed matrix and engine torque matrix to obtain the engine torque T corresponding to each gear at the current throttle opening. tq2 Secondly, when calculating the traction force of the vehicle in 8th gear, compare the engine torque corresponding to 8th gear at the current throttle opening with the engine torque corresponding to 9th gear at the current throttle opening; select the larger engine torque and compare it with the engine external characteristic torque corresponding to 8th gear; multiply the smaller value by the mechanical efficiency, the vehicle's final drive ratio, and the AMT's speed ratio in 8th gear, and divide the result by the vehicle's tire rolling radius to obtain the traction force corresponding to 8th gear.

[0082] S207: Obtain multiple operating parameters of the vehicle and determine the overall vehicle resistance based on these parameters.

[0083] Several operating parameters include the vehicle's total weight, vehicle speed, rolling resistance coefficient, and current slope. The total weight of the vehicle includes the vehicle's own weight and load.

[0084] Specifically, the formula for determining the vehicle's overall resistance based on multiple operating parameters is as follows:

[0085]

[0086] In the formula, F RLet m be the total vehicle resistance, g be the acceleration due to gravity, f be the rolling resistance coefficient, θ be the slope, and C be the total vehicle weight. D Where A is the air resistance coefficient and U is the frontal area. a Let 'a' represent the vehicle's speed, and 'a' represent the acceleration obtained by inputting the current throttle opening into the acceleration curve. The acceleration curve represents the mapping relationship between the vehicle's acceleration and the throttle opening; for example, the acceleration at 80% throttle is 0.08 m / s². 2 .

[0087] S208: The gear with the highest calculated traction force that is greater than the overall vehicle resistance is determined as the first target gear.

[0088] Specifically, Figure 3-2 This is a schematic diagram illustrating the principle of calculating the maximum gear at the current throttle opening, as provided by the present invention. Figure 3-2 As shown, to calculate whether a vehicle can shift from 7th to 8th gear, firstly, the total vehicle resistance that the vehicle needs to overcome in each gear is calculated. Secondly, the traction force of the vehicle in each gear is calculated. By calculating whether the traction force of the vehicle in any gear is greater than the total vehicle resistance corresponding to that gear, the highest gear among all gears that satisfy the condition that the traction force is greater than the total vehicle resistance is determined as the first target gear.

[0089] S209: When the vehicle enters a slope, the AMT shifts gears in a manner that does not exceed the first target gear.

[0090] In summary, the shift control method of the AMT in this embodiment of the invention obtains the engine torque of different gears at the current throttle opening and the engine external characteristic torque corresponding to different gears at a throttle opening of 100%. It calculates the traction force of the vehicle at different gears at the current throttle opening in real time, calculates the difference between the traction force corresponding to different gears and the vehicle's overall resistance, determines the largest gear among the gears that satisfy the difference being greater than zero as the first target gear, and controls the AMT shifting in a manner that does not exceed the first target gear. This can avoid cyclic shifting, thereby greatly improving the reliability and safety of AMT vehicles.

[0091] In another embodiment of the present invention, if the vehicle is in the starting phase, based on the above embodiment, after determining the gear with the largest calculated traction force greater than the overall vehicle resistance as the first target gear, the method further includes:

[0092] S301: Obtain the total weight of the vehicle and the gradient of the slope section.

[0093] S302: Input the total weight and slope into the pre-calibrated gear map to obtain the starting gear of the vehicle under the total weight and slope, where the gear map is the mapping relationship between the starting gear of the vehicle and the changes in the total weight and slope of the vehicle.

[0094] For example, if the vehicle is fully loaded with 49 tons and there is a 0% gradient, the starting gear is 3.

[0095] S303: If the first target gear is lower than the starting gear, then the starting gear will be set as the second target gear.

[0096] For example, if the gear with the greatest traction force exceeding the vehicle's resistance is 2, and the vehicle requires 3 to start, then the gear should be shifted to 3 to meet the vehicle's starting requirements.

[0097] S304: When the vehicle enters a slope, the AMT shifts gears in a manner that does not exceed the second target gear.

[0098] In summary, the shift control method of the AMT in this embodiment takes into account the influence of the vehicle's total weight and gradient on the starting gear. When the calculated first target gear is less than the starting gear, the target gear needs to be set to the vehicle's starting gear so that the vehicle can operate normally.

[0099] In another embodiment of the present invention, if the vehicle is set to a maximum gear that exceeds the specified limit, and the maximum gear that exceeds the specified limit is lower than the calculated first target gear, then after determining the gear with the highest calculated traction force greater than the overall vehicle resistance as the first target gear, the process includes:

[0100] S401: Obtain the maximum gear that exceeds the authority calibration.

[0101] S402: If the first target gear is greater than the maximum gear that exceeds the authority, then the maximum gear that exceeds the authority is determined as the third target gear.

[0102] Specifically, if a vehicle is on a 20% slope and is set to the maximum gear 7 (which is beyond the weight limit), and the calculated first target gear is 8, then the vehicle should remain in gear 7.

[0103] S403: When the vehicle enters a slope, the AMT shifts gears in a manner that does not exceed the third target gear.

[0104] In summary, the shift control method of the AMT in this embodiment, by considering that the maximum gear set by the vehicle is lower than the calculated first target gear, sets the maximum gear set by the vehicle to the target gear, thereby ensuring the safe operation of the vehicle.

[0105] Figure 4 This is a schematic diagram of the shift control device for an AMT provided by the present invention, as shown below. Figure 4As shown, the shift control device of the AMT includes: a parameter acquisition module 401, an input shaft speed acquisition module 402, an engine torque percentage acquisition module 403, an external characteristic torque calculation module 404, an engine torque acquisition module 405, a gear traction force calculation module 406, a vehicle resistance calculation module 407, a first target gear determination module 408, and a control module 409.

[0106] The parameter acquisition module 401 is used to acquire the vehicle's current throttle opening, engine reference torque, and current AMT output shaft speed.

[0107] The input shaft speed acquisition module 402 is used to calculate the input shaft speed of the AMT for each gear based on the current output shaft speed of the AMT and the speed ratio corresponding to each gear of the AMT, wherein the input shaft speed of the AMT for each gear is equal to the engine speed.

[0108] The engine torque percentage acquisition module 403 is used to input the input shaft speed of the AMT corresponding to each gear into the pre-calibrated engine external characteristic curve to obtain the engine torque percentage corresponding to each gear; wherein the engine external characteristic curve is the mapping relationship between the engine torque percentage corresponding to each gear at 100% throttle opening and the engine speed.

[0109] The external characteristic torque calculation module 404 is used to calculate the external characteristic torque of the vehicle at the current AMT output shaft speed based on the engine torque percentage and engine reference torque corresponding to each gear; where the external characteristic torque is the maximum driving torque at 100% throttle opening.

[0110] The engine torque acquisition module 405 is used to input the current throttle opening and the input shaft speed of the AMT corresponding to each gear into the pre-calibrated throttle pedal map to obtain the engine torque corresponding to each gear under the current throttle opening. The throttle pedal map is a mapping relationship between the engine torque under each gear and the changes in engine speed and throttle size.

[0111] The gear traction calculation module 406 is used to obtain the mechanical efficiency of the engine's powertrain, and calculate the vehicle's traction force in each gear based on the mechanical efficiency, the external characteristic torque corresponding to each gear at the current AMT output shaft speed, and the engine torque corresponding to each gear at the current throttle opening.

[0112] The vehicle resistance calculation module 407 is used to acquire multiple operating parameters of the vehicle and determine the vehicle resistance based on these parameters.

[0113] The first target gear determination module 408 is used to determine the gear with the largest traction force among the calculated gears that is greater than the overall vehicle resistance as the first target gear.

[0114] The control module 409 is used to control the AMT's gear shifting when the vehicle enters a slope section in a manner that does not exceed the first target gear.

[0115] Optionally, the shift control device of the AMT further includes a second target gear determination module 410, which is used to obtain the total weight of the vehicle and the gradient of the sloping road section; input the total weight and gradient into a pre-calibrated gear map to obtain the starting gear of the vehicle under the total weight and gradient, wherein the gear map is a mapping relationship between the starting gear of the vehicle and the changes in the total weight and gradient of the vehicle; if the first target gear is lower than the starting gear, the starting gear is determined as the second target gear; and the shifting of the AMT is controlled in a manner that does not exceed the second target gear when the vehicle enters the sloping road section.

[0116] Optionally, the shift control device of the AMT further includes a third target gear determination module 411, which is used to obtain the maximum gear that exceeds the authority calibration; if the first target gear is greater than the maximum gear that exceeds the authority calibration, the maximum gear that exceeds the authority calibration is determined as the third target gear; and the shifting of the AMT is controlled in a manner that does not exceed the third target gear when the vehicle enters the slope section.

[0117] Optionally, the external characteristic torque calculation module 404 calculates the external characteristic torque corresponding to each gear at the current AMT output shaft speed, using the following formula:

[0118] T tq1 =θ T *T ref

[0119] In the formula, T tq1 θ represents the external characteristic torque corresponding to each gear. T θ represents the percentage of engine torque corresponding to each gear. T Values ​​range from 0% to 100%, T ref This is the engine's reference torque.

[0120] Optionally, in the gear traction calculation module 406, the formula for calculating the vehicle's traction force in each gear is:

[0121]

[0122] In the formula, F T T represents the traction force corresponding to any gear. tq1 T represents the engine's external characteristic torque for any gear. tq2T represents the engine torque corresponding to any gear. tq2 ′ represents the engine torque corresponding to upshifting from any gear, i g i represents the gear ratios corresponding to each gear in an AMT (Automated Manual Transmission). o η is the final drive ratio of the vehicle, η is the mechanical efficiency, and r is the tire rolling radius of the vehicle.

[0123] Optionally, in the vehicle resistance calculation module 407, the formula for determining the vehicle's overall resistance is:

[0124]

[0125] In the formula, F R Let m be the total vehicle resistance, g be the acceleration due to gravity, f be the rolling resistance coefficient, θ be the slope, and C be the total vehicle weight. D Where A is the air resistance coefficient and U is the frontal area. a Let be the vehicle's speed, and 'a' be the acceleration obtained by inputting the current throttle opening into the acceleration curve, where the acceleration curve is a mapping relationship between the vehicle's acceleration and the throttle opening.

[0126] The AMT shift control device provided in this embodiment can perform... Figure 2 The technical solution of the method embodiment shown has the same implementation principle and technical effect as... Figure 2 The methods and embodiments shown are similar and will not be described in detail here.

[0127] According to embodiments of the present invention, the present invention also provides an electronic control unit for an AMT, a computer-readable storage medium, and a computer program product.

[0128] like Figure 5 As shown, Figure 5 This is a schematic diagram of the electronic control unit (ECU) of an AMT (Automated Manual Transmission) provided by the present invention. The ECU is intended for use with various electronic devices capable of executing the shift control method of an AMT, such as microcomputers, single-chip microcomputers, and other suitable computers. 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.

[0129] like Figure 5 As shown, the electronic control unit of the AMT includes a processor 501 and a memory 502. The memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory to implement the shift control method of the AMT in the above embodiment.

[0130] The memory 502 is the computer-readable storage medium provided by the present invention. The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the shift control method of the AMT in the above embodiment.

[0131] The memory 502, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to the AMT shift control method in the embodiments of the present invention. The processor 501 executes various functional applications and data processing by running the software programs, instructions, and modules stored in the memory 502, thereby implementing the AMT shift control method in the above method embodiments.

[0132] In addition, this embodiment also provides a computer program product, including a computer program, which, when the instructions in the computer program product are executed by a processor, enables the AMT shift control method of the above embodiment to be executed.

[0133] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. The invention is intended to cover any variations, uses, or adaptations of the embodiments thereof that follow the general principles of the embodiments and include common knowledge or customary techniques in the art not disclosed in the embodiments thereof. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the claims.

[0134] It should be understood that the embodiments of the present invention are not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from their scope. The scope of the embodiments of the present invention is limited only by the appended claims.

Claims

1. A shift control method for an automatic transmission (AMT), characterized in that, When the AMT's electronic control unit detects that the vehicle has entered a slope section, it performs the following steps: Obtain the vehicle's current throttle opening, engine reference torque, and current AMT output shaft speed; Based on the current output shaft speed of the AMT and the speed ratio corresponding to each gear of the AMT, the input shaft speed of the AMT corresponding to each gear is calculated, wherein the input shaft speed of the AMT corresponding to each gear is equal to the engine speed; The input shaft speed of the AMT corresponding to each gear is input into the pre-calibrated engine external characteristic curve to obtain the engine torque percentage corresponding to each gear; wherein the engine external characteristic curve is the mapping relationship between the engine torque percentage corresponding to each gear at 100% throttle opening and the engine speed. Based on the engine torque percentage corresponding to each gear and the engine reference torque, the external characteristic torque of the vehicle at the current AMT output shaft speed is calculated for each gear; where the external characteristic torque is the maximum driving torque at 100% throttle opening; The current throttle opening and the AMT input shaft speed corresponding to each gear are input into the pre-calibrated throttle pedal map to obtain the engine torque corresponding to each gear under the current throttle opening. The throttle pedal map is a mapping relationship between the engine torque under each gear and the engine speed and throttle size. The mechanical efficiency of the engine's powertrain is obtained, and based on the mechanical efficiency, the external characteristic torque corresponding to each gear at the current AMT output shaft speed, and the engine torque corresponding to each gear at the current throttle opening, the traction force of the vehicle in each gear is calculated. Obtain multiple operating parameters of the vehicle, and determine the overall vehicle resistance based on the multiple operating parameters; The gear with the highest calculated traction force that is greater than the overall vehicle resistance is determined as the first target gear. The AMT is controlled to shift gears in a manner that does not exceed the first target gear when the vehicle enters a slope section.

2. The method according to claim 1, characterized in that, After determining the gear with the largest calculated traction force exceeding the overall vehicle resistance as the first target gear, the process further includes: Obtain the total weight of the vehicle and the slope of the sloping road section; The total weight and the slope are input into a pre-calibrated gear map to obtain the starting gear of the vehicle under the total weight and the slope, wherein the gear map is a mapping relationship between the starting gear of the vehicle and the changes in the total weight and the slope of the vehicle. If the first target gear is lower than the starting gear, then the starting gear is determined as the second target gear; The AMT is controlled to shift gears in a manner that does not exceed the second target gear when the vehicle enters a slope section.

3. The method according to claim 1, characterized in that, After determining the gear with the largest calculated traction force exceeding the overall vehicle resistance as the first target gear, the process further includes: Obtain the maximum gear that exceeds the allowed calibration; If the first target gear is greater than the maximum gear that exceeds the authority, then the maximum gear that exceeds the authority is determined as the third target gear. The AMT is controlled to shift gears in a manner that does not exceed the third target gear when the vehicle enters the sloping road section.

4. The method according to claim 1, characterized in that, The formula for calculating the external characteristic torque of the vehicle at the current AMT output shaft speed, based on the engine torque percentage corresponding to each gear and the engine reference torque, is as follows: T tq1 =θ T *T ref In the formula, T tq1 θ represents the external characteristic torque corresponding to each gear position. T The percentage of engine torque corresponding to each gear, where θ T Values ​​range from 0% to 100%, T ref This is the reference torque for the engine.

5. The method according to claim 1, characterized in that, The formula for calculating the traction force of the vehicle in each gear is as follows: In the formula, F T T represents the traction force corresponding to any gear. tq1 T represents the engine's external characteristic torque corresponding to any of the gears. tq2 T represents the engine torque corresponding to any of the gears. tq2 ′ represents the engine torque corresponding to upshifting from any of the gears, i g Let i be the speed ratio corresponding to each gear of the AMT. o η is the final drive ratio of the vehicle, η is the mechanical efficiency, and r is the tire rolling radius of the vehicle.

6. The method according to claim 1, characterized in that, The multiple operating parameters include the total weight of the vehicle, the vehicle's speed, the rolling resistance coefficient, and the gradient; Accordingly, the formula for determining the vehicle's overall resistance based on the aforementioned multiple operating parameters is as follows: In the formula, F R Let m be the total vehicle resistance, g be the gravitational acceleration, f be the rolling resistance coefficient, θ be the slope, and C be the total vehicle weight. D Where A is the air resistance coefficient and U is the frontal area. a Let be the vehicle's speed, and 'a' be the acceleration obtained by inputting the current throttle opening into the acceleration curve, where the acceleration curve is a mapping relationship between the vehicle's acceleration and the throttle opening.

7. A shift control device for an AMT (Automated Manual Transmission), characterized in that, When the AMT's electronic control unit detects that the vehicle has entered a slope section, it includes: The parameter acquisition module is used to acquire the vehicle's current throttle opening, engine reference torque, and current AMT output shaft speed. The input shaft speed acquisition module is used to calculate the input shaft speed of the AMT for each gear based on the current output shaft speed of the AMT and the speed ratio corresponding to each gear of the AMT, wherein the input shaft speed of the AMT for each gear is equal to the engine speed; The engine torque percentage acquisition module is used to input the input shaft speed of the AMT corresponding to each gear into a pre-calibrated engine external characteristic curve to obtain the engine torque percentage corresponding to each gear; wherein the engine external characteristic curve is the mapping relationship between the engine torque percentage and the engine speed at 100% throttle opening in each gear. The external characteristic torque calculation module is used to calculate the external characteristic torque of the vehicle at the current AMT output shaft speed based on the engine torque percentage corresponding to each gear and the engine reference torque; wherein the external characteristic torque is the maximum driving torque at 100% throttle opening; The engine torque acquisition module is used to input the current throttle opening and the input shaft speed of the AMT corresponding to each gear into a pre-calibrated throttle pedal map to obtain the engine torque corresponding to each gear under the current throttle opening, wherein the throttle pedal map is a mapping relationship between the engine torque under each gear and the engine speed and the throttle size. The gear traction calculation module is used to obtain the mechanical efficiency of the engine's powertrain, and calculate the traction force of the vehicle in each gear based on the mechanical efficiency, the external characteristic torque corresponding to each gear at the current AMT output shaft speed, and the engine torque corresponding to each gear at the current throttle opening. The vehicle resistance calculation module is used to obtain multiple operating parameters of the vehicle and determine the vehicle resistance based on the multiple operating parameters. The first target gear determination module is used to determine the gear with the largest traction force among the calculated gears that is greater than the overall vehicle resistance as the first target gear; The control module is used to control the AMT to shift gears in a manner that does not exceed the first target gear when the vehicle enters a slope section.

8. An electronic control unit for an AMT, characterized in that, include: Memory and processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory to implement the shift control method of the AMT as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the shift control method of the AMT as described in any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the shift control method of the AMT as described in any one of claims 1 to 6.

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