A shift control method for an AMT transmission

Abstract

This invention discloses a shift control method for an AMT (Automated Manual Transmission) gearbox, relating to the field of automotive transmission system control technology. The method includes the following steps: acquiring vehicle operating information during shifting; the vehicle operating information includes the power source speed and the target speed for the gear; and determining the optimal timing for engagement of the transmission's primary and secondary gears based on the vehicle operating information and a gear meshing judgment model; the judgment model is: E = ω t -ω r ω t ω is the target RPM function for the gear position. r t is a function of the rotational speed of the power source; a t is the initial time per unit. b The unit end time; firstly based on the power source speed ω r and gear target speed ω t Determine the first closing time T0; at time T0, ω r (T0)=ω t (T0); Starting from time T0, when the area S ≤ the area threshold A, the optimal time for master and slave gear engagement is determined. The above scheme reduces gear wear and vehicle jerking and vibration during gear shifting.

Description

Technical Field

[0001] This invention relates to the field of automotive transmission system control technology, and in particular to a shift control method for an AMT (Automated Manual Transmission) gearbox. Background Technology

[0002] Modern commercial vehicles typically employ a power transmission system that includes an engine / drive motor, an AMT (Automated Manual Transmission) gearbox, a drivetrain, and a differential. This system transmits power from the power source to the axles, driving the wheels. The AMT gearbox, acting as a connector between the vehicle's power source and drivetrain, is the core component responsible for synchronizing the speeds of the power source and drivetrain during gear shifts and changing the gear ratio. In an AMT gearbox, the input shaft of the engine / drive motor connects to the output shaft of the drivetrain. Several driving gear sets at the input shaft mesh with driven gear sets at the output shaft. The driving gear sets drive the driven gear sets through friction. During gear shifts, the input and output shafts are first disconnected, cutting off the power connection. The input shaft then re-engages with the output shaft with a different number of gears, changing the gear ratio to achieve a gear change.

[0003] During gear shifting, the timing of the engagement of the master and driven gear sets within the AMT transmission is crucial for smooth power transmission and vehicle ride comfort. This requires maintaining a certain speed difference between the two gear shafts. However, before the master and driven gears re-engage in the AMT transmission, due to factors such as the power source control method and vehicle speed variations under different operating conditions, overshoot often occurs when the engine / drive motor speed rapidly approaches the gear selector speed. This means the power source accelerates too quickly, exceeding the speed range within which the master and driven gears can engage. If the gears engage when the power source speed is too high or too low compared to the gear selector speed, forcing the driven gear to mesh with the driving gear will cause significant gear wear and impact the entire vehicle's transmission system, resulting in noticeable jerking and vibration in the vehicle.

[0004] Therefore, determining the appropriate timing for gear engagement of the AMT transmission's master and slave gears during gear shifting, in order to reduce gear wear and vehicle jerking and vibration, is a problem that urgently needs to be solved. Summary of the Invention

[0005] In order to reduce gear wear and vehicle jerking and vibration during gear shifting, this application provides a shift control method for an AMT transmission.

[0006] In a first aspect, this application provides a shift control method for an AMT (Automated Manual Transmission) gearbox, employing the following technical solution, the method comprising the following steps:

[0007] S100: Real-time acquisition of vehicle operating information during gear shifting; the vehicle operating information includes power source speed and target speed for the gear.

[0008] S200: Based on the vehicle operation information and the pre-built gear meshing judgment model, determine the optimal timing for the engagement of the transmission master and slave gears, and control the master and slave gears to engage at the optimal timing.

[0009] By adopting the above technical solution and using a judgment model corresponding to the actual vehicle conditions, the master and slave gears of the AMT transmission can be controlled to mesh at the optimal time during gear shifting, avoiding overshoot, reducing gear wear and vehicle jerking and vibration, extending component life, and improving vehicle ride smoothness.

[0010] In one specific feasible implementation, the gear meshing determination model is as follows:

[0011]

[0012] Where, E=ω t -ω r ω t Let ω be the target speed function for the gear position, which characterizes the relationship between the target speed for the gear position and the shift time; r Let t be the power source speed function, which characterizes the relationship between the power source speed and the shift time; a t is the initial time per unit. b End time in units;

[0013] Based on the power source speed function ω r and gear target speed function ω t Determine the first closing time T0. At time T0, ω r (T0)=ω t (T0);

[0014] Based on the power source speed function ω r Gear target speed function ω t The first closing time T0 and the gear meshing judgment model, starting from time T0, when the area S ≤ area threshold A, determine the current time as the optimal time for the gearbox master and slave gears to mesh, and control the master and slave gears to mesh.

[0015] By adopting the above technical solution, based on the real-time changes in the target speed of the gear and the speed of the power source, and combined with the gear meshing judgment model, the optimal timing for the meshing of the main and driven gears of the transmission can be accurately determined.

[0016] In a specific feasible implementation, t is set b -t aThe value is for unit time t. When constructing the gear meshing judgment model, the values ​​of unit time t and area threshold A are determined, including:

[0017] S10: Under stable operating conditions, obtain the first speed function of the vehicle's power source and the first target speed function of the gear during the gear shifting process; the first speed function of the power source represents the correspondence between the first speed of the power source and the gear shifting time; the first target speed function of the gear represents the correspondence between the first target speed of the gear and the gear shifting time.

[0018] S20: Based on the first speed function of the power source and the first target speed function of the gear, determine the range of values ​​for the first engagement time and unit time t;

[0019] S30: Under unstable operating conditions, acquire the second speed function of the vehicle's power source and the second target speed function of the gear during the gear shifting process; the second speed function of the power source represents the correspondence between the second speed of the power source and the shifting time; the second target speed function of the gear represents the correspondence between the second target speed of the gear and the shifting time.

[0020] S40: Based on the second speed function of the power source, the second target speed function of the gear, the range of the first engagement time and the unit time t, determine the values ​​of the unit time t and the area threshold A.

[0021] By adopting the above technical solution, the range of values ​​for unit time t in the gear meshing judgment model is obtained under stable operating conditions. Then, the speed change under unstable operating conditions is simulated, and a comprehensive judgment is made to obtain the value of unit time t suitable for various operating conditions and the corresponding area threshold A. The applicability of this gear meshing judgment model is more extensive, so that in the actual operation of the vehicle, when shifting gears under various operating conditions, the gear meshing judgment model can better determine the meshing timing, so that the master and slave gears can complete the meshing as early and reasonably as possible, reducing gear wear and vehicle jerking and vibration, extending component life, and improving the smoothness of vehicle driving.

[0022] In one specific implementation, step S20 includes:

[0023] S21: Based on the first speed function of the power source, the first target speed function of the gear, and multiple first preset unit times t1, determine the first engagement time and generate a first area change function corresponding to each first preset unit time t1; the first area change function characterizes the correspondence between the first area and the shift time, and the first area characterizes the area between the first speed function of the power source and the first target speed function of the gear when the unit time t is the first preset unit time t1;

[0024] S22: Determine the range of values ​​for unit time t based on the first area change function and the first engagement time corresponding to each first preset unit time t1.

[0025] By adopting the above technical solution and making a preliminary judgment under stable operating conditions, the range of values ​​for unit time t is obtained, thus limiting the value of unit time to a smaller range.

[0026] In one specific implementation, step S40 includes:

[0027] S41: Select multiple second preset unit times t2 within the range of the unit time t;

[0028] S42: Based on the second speed function of the power source, the second target speed function of the gear, the first engagement time, and the second preset unit time t2, generate a second area change function corresponding to each second preset unit time t2 under the first engagement time; the second area change function characterizes the correspondence between the second area and the acceleration of the second target speed of the gear, and the second area characterizes the area between the second speed function of the power source and the second target speed function of the gear when the unit time t is the second preset unit time t2;

[0029] S43: Based on the second area change function corresponding to each preset unit time t2, determine the value of unit time t and area threshold A; the unit time t is one of the second preset unit time t2.

[0030] By adopting the above technical solution, the exact values ​​of unit time t and area threshold A are obtained through secondary judgment under unstable working conditions, thereby improving the construction accuracy of the gear meshing judgment model.

[0031] In one specific implementation scheme, the process of determining the area threshold A includes:

[0032] Multiple discrete points are selected from the second area change function corresponding to the unit time t;

[0033] Based on the second area set corresponding to the plurality of discrete points, the average value of the second area set is determined; the average value of the second area set is the area threshold A.

[0034] In one specific implementation scheme, the calculation process of the area S includes:

[0035] t a to t b The time interval is divided into several time sub-intervals;

[0036] Calculate the area between the power source speed function and the gear target speed function in each time period;

[0037] Based on the area between the power source speed function and the gear target speed function within each time period, determine the speed from t... a to t b The area S between the power source speed function and the gear target speed function within a given time interval.

[0038] By adopting the above technical solution, irregular curves are divided into relatively regular straight lines according to time periods, and the areas of each segment are added together to obtain a more accurate area value, thus improving the calculation accuracy.

[0039] Secondly, this application provides a shift control device for an AMT transmission, which adopts the following technical solution: the device applies the shift control method described in the first aspect above, and the device includes an information acquisition unit and a engagement control unit; the information acquisition unit is used to acquire vehicle operating information in real time during the shift process; the vehicle operating information includes the power source speed and the target speed of the gear;

[0040] The engagement control unit is used to determine the optimal timing for the engagement of the transmission master and slave gears based on the vehicle operating information and a pre-built gear engagement judgment model, and to control the master and slave gears to engage at the optimal timing.

[0041] Thirdly, this application provides a terminal, the terminal comprising: a processor, a memory, and a communication bus; the communication bus is used to realize the connection and communication between the processor and the memory, and the processor is used to execute one or more programs stored in the memory to implement the steps of the shift control method as described in the first aspect.

[0042] Fourthly, this application provides a computer-readable storage medium storing instructions that, when executed, perform the steps of the shift control method as described in the first aspect.

[0043] In summary, the technical solution of this application includes at least the following beneficial technical effects:

[0044] 1. By using a judgment model that corresponds to the actual condition of the vehicle, the master and slave gears of the AMT transmission are controlled to mesh at the optimal time during gear shifting, avoiding overshoot, reducing gear wear and vehicle jerking and vibration, extending component life, and improving the smoothness of vehicle driving.

[0045] 2. By obtaining the range of values ​​for unit time t in the gear meshing judgment model under stable operating conditions, and then simulating the speed change under unstable operating conditions, a comprehensive judgment is made to obtain the value of unit time t suitable for various operating conditions and the corresponding area threshold A. This gear meshing judgment model has a wider applicability, enabling the gear meshing judgment model to better determine the meshing timing when shifting gears under various operating conditions during actual vehicle operation, so that the master and slave gears can complete meshing as early and reasonably as possible. Attached Figure Description

[0046] Figure 1 This is an overall flowchart of the shift control method in the embodiments of this application;

[0047] Figure 2 This is a flowchart illustrating the determination of unit time t and area threshold A in the gear meshing judgment model in this application embodiment;

[0048] Figure 3 This is a waveform diagram of the first speed function of the power source and the first target speed function of the gear when vehicle X shifts up in this embodiment of the application;

[0049] Figure 4 This is a waveform diagram of the first area change function corresponding to each first preset unit time t1 in the embodiments of this application;

[0050] Figure 5 This is a waveform diagram of the second speed function of the power source and the second target speed function of the gear when the acceleration of the second target speed of the gear is -200 rpm / s in the embodiment of this application;

[0051] Figure 6 This is a waveform diagram of the second speed function of the power source and the second target speed function of the gear when the acceleration of the second target speed of the gear is 200 rpm / s in the embodiment of this application;

[0052] Figure 7 This is a waveform diagram of the second area change function corresponding to each second pre-selected unit time t2 in the embodiments of this application;

[0053] Figure 8 This is a waveform diagram of the first speed function of the power source and the first target speed function of the gear when vehicle X downshifts in this embodiment of the application;

[0054] Figure 9 This is the waveform of the power source speed and the target speed of the gear when the bus accelerates and shifts gears under stable operating conditions in the embodiments of this application;

[0055] Figure 10 This is the first area change function of the passenger car in the embodiments of this application;

[0056] Figure 11This is the second area change function of the bus under unstable operating conditions in the embodiments of this application;

[0057] Figure 12 This is a waveform diagram of the power source speed and the target speed of the gear when the bus actually shifts gears in the embodiments of this application. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be further described in detail below with reference to the accompanying drawings.

[0059] Example 1:

[0060] This embodiment discloses a shift control method for an AMT transmission, referring to... Figure 1 The method includes the following steps:

[0061] S100: Real-time acquisition of vehicle operating information during gear shifting; the vehicle operating information includes power source speed and target speed for the gear.

[0062] S200: Based on the vehicle operation information and the pre-built gear meshing judgment model, determine the optimal timing for the engagement of the transmission master and slave gears, and control the master and slave gears to engage at the optimal timing.

[0063] Before shifting gears, the gear target speed represents the target speed of the power source before shifting gears; after shifting gears, the gear target speed represents the target speed of the power source after shifting gears.

[0064] Therefore, by using a judgment model that corresponds to the actual condition of the vehicle, the master and slave gears of the AMT transmission can be controlled to mesh at the optimal time during gear shifting, avoiding overshoot, reducing gear wear and vehicle jerking and vibration, extending component life, and improving the smoothness of vehicle driving.

[0065] Furthermore, the gear meshing determination model is as follows:

[0066]

[0067] Where, E=ω t -ω r ω t Let ω be the target speed function for the gear position, which characterizes the relationship between the target speed for the gear position and the shift time; r Let be the power source speed function, which represents the correspondence between the power source speed and the shift time; E is the speed difference function, which represents the correspondence between the speed difference and the shift time, where the speed difference is the difference between the target speed of the gear and the power source speed; t a t is the initial time per unit. b The unit end time is S, where S is the time from t.a to t b The area between the power source speed function and the gear target speed function over a time interval;

[0068] Based on the power source speed function ω r and gear target speed function ω t Determine the first closing time T0; at time T0, ω r (T0)=ω t (T0);

[0069] Based on the power source speed function ω r Gear target speed function ω t The first closing time T0 and the gear meshing judgment model, starting from time T0, when the area S ≤ area threshold A, determine the current time as the optimal time for the gearbox master and slave gears to mesh, and control the master and slave gears to mesh.

[0070] Therefore, based on the real-time changes in the target speed of the gear and the speed of the power source, combined with the gear meshing judgment model, the optimal timing for the meshing of the transmission's master and slave gears can be accurately determined.

[0071] Furthermore, the calculation process for the area S includes:

[0072] t a to t b The time interval is divided into several time sub-intervals;

[0073] Calculate the area between the power source speed function and the gear target speed function in each time period;

[0074] Based on the area between the power source speed function and the gear target speed function within each time period, determine the speed from t... a to t b The area S between the power source speed function and the gear target speed function within a given time interval.

[0075] Therefore, by dividing the irregular curve into relatively regular straight lines according to time periods, and adding the areas of each segment together, a more accurate area value can be obtained, thus improving the calculation accuracy.

[0076] Preferably, to improve the calculation accuracy of area S and make the area values ​​calculated continuously in each time period more accurate, thereby making the judgment of the meshing time of the master and slave gears more accurate and the response faster, the time period can be 0.001s interval, that is, the target speed of each gear of the power source is obtained every 0.001s. The changes in the speed of the power source and the changes in the target speed of the gear within 0.001s can be regarded as linear changes, so as to calculate the area between the two functions within 0.001s, and finally from t a to t bThe precise value of S can be obtained by adding the areas between the power source speed function and the gear target speed function corresponding to all 0.001s within the time interval.

[0077] Furthermore, set t b -t a The value is per unit time t. When constructing the gear meshing judgment model, the values ​​of unit time t and area threshold A are determined, including an initial calculation and a secondary calculation process. Specifically, the initial calculation process includes steps S10 to S20:

[0078] S10: Under stable operating conditions, obtain the first speed function of the vehicle's power source and the first target speed function of the gear during the gear shifting process; the first speed function of the power source represents the correspondence between the first speed of the power source and the shifting time; the first target speed function of the gear represents the correspondence between the first target speed of the gear and the shifting time; furthermore, under stable operating conditions, the first target speed of the gear remains unchanged after the gear shift;

[0079] S20: Based on the first speed function of the power source and the first target speed function of the gear, determine the range of values ​​for the first engagement time and unit time t; the first engagement time characterizes the optimal engagement time of the master and slave gears under stable working conditions.

[0080] Specifically, step S20 above includes:

[0081] S21: Based on the first speed function of the power source, the first target speed function of the gear, and multiple first preset unit times t1, determine the first engagement time and generate a first area change function corresponding to each first preset unit time t1; the first area change function characterizes the correspondence between the first area and the shift time, and the first area characterizes the area between the first speed function of the power source and the first target speed function of the gear when the unit time t is the first preset unit time t1;

[0082] S22: Based on the first area change function and the first engagement time corresponding to each first preset unit time t1, determine the range of values ​​for unit time t.

[0083] Therefore, steps S21 and S22, through preliminary determination under stable operating conditions, obtain the range of values ​​for unit time t, which can limit the value of unit time to a smaller range.

[0084] Specifically, in combination Figures 3-7 Using the waveform diagram and taking vehicle X shifting gears as an example, this embodiment provides a detailed explanation of the process for confirming the unit time and area threshold A. Figure 3Under stable operating conditions, the waveforms of the first speed of the vehicle X power source and the first target speed of the gear during the simulated upshift process are plotted with the shift time. The horizontal axis represents the shift time in seconds, and the vertical axis represents the speed in rpm. Figure 3 The diagram shows the waveform of the first target speed of the gear decreasing from 2000 rpm before the shift to 1400 rpm after the shift at 0.1s, and stabilizing at 1400 rpm. It also shows the waveform of the first speed of the power source changing with the shift time during this process. Vehicle X starts shifting at 0.1s. The master and slave gears of the power source input shaft and the transmission system output shaft are disconnected at the same speed at 0.1s. The gearbox changes the gear set and speed ratio. Due to mechanical inertia, the first speed of the power source starts to decrease from 0.15s. After fluctuation, the difference between the first target speed of the gear and the first target speed of the gear eventually stabilizes within a certain range.

[0085] It is generally suitable for engaging the master and slave gears when the difference between the first speed of the power source and the first target speed of the gear is set to within ±50 rpm. Of course, those skilled in the art can set other values ​​for the range, and this application does not limit this. Figure 3 As shown, based on the difference between the two functions being ±50 rpm, the graph can be divided into three regions: Closed Point 1, Closed Point 2, and Closed Point 3. Closed Point 1 is the region where the difference between the first speed of the power source and the first target speed of the gear is within ±50 rpm as the power source's first speed continuously decreases from the shift point. Closed Point 3 is the region where the difference between the first speed of the power source and the first target speed of the gear is within ±50 rpm as the speed recovers. The region corresponding to the shift time between Closed Point 1 and Closed Point 3 is Closed Point 2.

[0086] When the first speed of the power source drops to the closed-point 1 region, the acceleration of the first speed of the power source is relatively large at this time, that is, the speed acceleration of the engine or drive motor is relatively large. If the transmission system is connected through the gearbox at this time and the meshing of the master and slave gears is controlled, there may be an overshoot inertial tendency. On the one hand, a large amount of sliding friction will be generated between the master and slave gears, forcing the speed of the power source input shaft to be forcibly pulled back to the gear speed to counteract the overshoot inertia. On the other hand, the intense friction between the driving gear and the driven gear will generate high temperature, causing gear wear.

[0087] When the first speed of the power source drops to the closed point 2 region, since the first speed of the power source is too low than the first target speed of the gear, if the transmission system is connected through the gearbox at this time to control the meshing of the master and slave gears, it will not only cause the above-mentioned friction between the master and slave gears, but also make the vehicle jerky and the vehicle speed drop significantly, affecting the smoothness of the vehicle driving. Therefore, both the closed point 1 region and the closed point 2 region are unstable closed regions.

[0088] Therefore, when the acceleration of the first speed of the power source gradually decreases and reaches the stable region of the closure point 3, that is, after 0.345s, the difference between the first speed of the power source and the first target speed of the gear remains stable at ±50rpm and there will be no overshoot. If the master and slave gears are engaged at this time to realize the connection between the power source and the transmission system, smooth gear shifting can be achieved, the wear on the gearbox gears is minimized, and there is no impact on the smoothness of the vehicle's driving. The closure point 3 region is a stable closed region.

[0089] according to Figure 3 It can be seen that the region of closure point 3 starts from 0.345s, that is, according to Figure 3 The first speed function of the power source and the first target speed function of the gear can determine that the first engagement time is 0.345s.

[0090] When according to Figure 3 After determining the first speed function of the power source and the first target speed function of the gear, and setting the first engagement time to 0.345s, the range of values ​​for the unit time t is further determined based on multiple preset first preset unit times t1. Figure 4 The diagram shows the first area change function corresponding to each of the first preset unit time t1 being 0.05s, 0.10s, 0.15s, 0.20s, 0.25s, and 0.30s. (Refer to...) Figure 4 The horizontal axis represents the shift time in seconds, and the vertical axis represents the area between the first speed function of the power source and the first target speed function of the gear, in rpm·s. Figure 4 Each function in the diagram represents the first area change function corresponding to different unit times. Of course, in order to improve the accuracy of the range of values ​​for the unit time t, more first preset unit times t1 can be selected, such as t1 being 0.04s, 0.03s, or smaller values, and the corresponding function graphs can be plotted. This application does not impose any restrictions on this.

[0091] Depend on Figure 4 It can be seen that the two functions for t1 = 0.05s and t1 = 0.10s exhibit repeated fluctuations around the first engagement time of 0.345s. This repeated fluctuation constitutes a large blind zone. If the area between the first speed function of the power source and the first target speed function of the gear is calculated within this blind zone, it is easy to cause misjudgment, resulting in the system engaging too early or too late. Therefore, the value of the unit time should not be too short. When the unit time is increased, that is, in the function corresponding to t1 greater than 0.10s, the range of the blind zone is reduced.

[0092] The two functions with t1 = 0.25s and t1 = 0.30s have excessive time, and the area between the first speed function of the power source and the first target speed function of the gear continuously increases. This causes the timing of the master and slave gear engagement to be delayed to a minimum of 0.25s and 0.3s. At this time, the requirement of engaging the gears as soon as possible cannot be met, which will also affect the shifting performance and driving smoothness.

[0093] Therefore, according to Figure 4 The first area change function corresponding to each unit time allows us to determine that the range of values ​​for the unit time t is 0.1s to 0.25s, i.e., 0.1s. <t<0.25s。

[0094] The secondary calculation process includes steps S30 to S40:

[0095] S30: Under unstable operating conditions, acquire the second speed function of the vehicle's power source and the second target speed function of the gear during gear shifting; the second speed function of the power source represents the correspondence between the second speed of the power source and the shifting time; the second target speed function of the gear represents the correspondence between the second target speed of the gear and the shifting time; under unstable operating conditions, the second target speed of the gear changes after the gear shift, that is, the speed acceleration of the second target speed of the gear changes after the gear shift.

[0096] S40: Based on the second speed function of the power source, the second target speed function of the gear, the range of the first engagement time and the unit time t, determine the values ​​of the unit time t and the area threshold A.

[0097] Therefore, by obtaining the range of values ​​for unit time t in the gear meshing judgment model under stable operating conditions, and then simulating the speed change under unstable operating conditions, a comprehensive judgment is made to obtain a value of unit time t suitable for various operating conditions and the corresponding area threshold A. This gear meshing judgment model has a wider applicability, enabling it to better determine the meshing timing when shifting gears under various operating conditions during actual vehicle operation. This allows the master and slave gears to complete meshing as early and reasonably as possible, reducing gear wear and vehicle jerking and vibration, extending component life, and improving the smoothness of vehicle driving.

[0098] Specifically, in the above-mentioned secondary calculation process, step S40 includes:

[0099] S41: Select multiple second preset unit times t2 within the range of the unit time t;

[0100] S42: Based on the second speed function of the power source, the second target speed function of the gear, the first engagement time, and the second preset unit time t2, generate a second area change function corresponding to each second preset unit time t2 under the first engagement time; the second area change function characterizes the correspondence between the second area and the acceleration of the second target speed of the gear, and the second area characterizes the area between the second speed function of the power source and the second target speed function of the gear when the unit time t is the second preset unit time t2;

[0101] S43: Based on the second area change function corresponding to each preset unit time t2, determine the value of unit time t and area threshold A; the unit time t is one of the second preset unit time t2.

[0102] Therefore, steps S41, S42, and S43, through secondary determination under unstable working conditions, obtain the exact values ​​of unit time t and area threshold A, thereby improving the construction accuracy of the gear meshing judgment model.

[0103] Further, in step S43, the process of determining the area threshold A includes:

[0104] Multiple discrete points are selected from the second area change function corresponding to the unit time t;

[0105] Based on the second area set corresponding to the plurality of discrete points, the average value of the second area set is determined; the average value of the second area set is the area threshold A.

[0106] Because the vehicle's operating conditions may be unstable during gear shifting, the target speed for the gear may fluctuate and change during the shift. (Refer to...) Figure 5 and Figure 6 This simulates the power source speed and target gear speed under different operating conditions after the transmission disconnects the power connection, based on road conditions and gradient. Figure 5 The waveform diagram shows the second target speed in gear decreasing from the initial 2000 rpm to 1400 rpm, and then running with an acceleration of -200 rpm / s, as well as the waveform diagram of the second speed of the power source changing with the shift time during this process. Figure 6 The diagram shows the waveform corresponding to the second target speed in gear decreasing from an initial 2000 rpm to 1400 rpm, and then accelerating at 200 rpm / s. It also shows the waveform of the second power source speed changing with shift time during this process. Of course, there are many other waveforms showing the changes in power source speed and target speed with shift time when acceleration is between -200 rpm / s and 200 rpm / s, but these are not shown in the attached diagram.

[0107] It can be seen that affected by the change of the second target speed of the gear position, the second speed of the power source and the area between the two will also change accordingly. When the acceleration of the second target speed of the gear position is negative, the meshing time of the master and slave gears is shortened; when the acceleration of the second target speed of the gear position is positive, the meshing time of the master and slave gears is lengthened. Therefore, in different working conditions, the selected area threshold A should be universal and needs to be kept within a small fluctuation range.

[0108] Referring to Figure 7 , within the range of the value of the unit time t, that is, within the range of 0.1s < t < 0.25s, multiple second preset unit times t2 are selected again, and the corresponding second area change function is plotted. Figure 7 Illustrates several cases where the selected unit time t2 is 0.11s, 0.12s, 0.13s, 0.14s, 0.15s, 0.16s, 0.17s, 0.18s, 0.19s, 0.20s. Of course, there are also cases where the unit time t2 is 0.21s, 0.22s, 0.23s, 0.24s, which are not shown in the figure. Referring to Figure 7 , the abscissa represents the acceleration of the second target speed of the gear position, with the unit of rpm / s, and the ordinate represents the area between the second speed function of the power source and the second target speed function of the gear position, with the unit of rpm·s. Figure 7 Each function in represents the second area change function corresponding to different second preset unit times t2 at the moment when the meshing time is 0.345s. For example, the function of t2 = 0.11s represents that when the second preset unit time is 0.11s, under the conditions that the accelerations of the second target speed of the gear position are -200rpm / s, -100rpm / s, 0, 100rpm / s, 200rpm / s respectively, the areas between the corresponding second speed function of the power source and the second target speed function of the gear position are plotted to obtain the corresponding waveform diagram. Of course, in order to improve the calculation accuracy, the selection of the second preset unit time t2 can also be made more refined. For example, it can be further refined into 0.111s, 0.112s, 0.113s, etc. between 0.11s and 0.12s, or more acceleration values can be selected. This application does not limit the comparison.

[0109] From Figure 7 it can be seen that when the value of the second preset unit time t2 is small, less than 0.16s, when the master and slave gears are meshing, the area between the two functions rises with the increase of the acceleration, and the function fluctuates greatly. When the value of the second preset unit time t2 is large, greater than 0.16s, when the master and slave gears are meshing, the integral area between the two functions decreases with the increase of the acceleration, and the function still fluctuates greatly.

[0110] When the second preset unit time t2 is 0.16s, the corresponding function is relatively smooth with minimal fluctuations. Therefore, the optimal second preset unit time t2 can be determined to be 0.16s, i.e., the optimal unit time t is 0.16s. Based on the function with t2 = 0.16s in the graph, multiple discrete points can be selected to calculate the average value of the function's ordinate. For example, selecting points with abscissas of -200rpm / s, -100rpm / s, 0, 100rpm / s, and 200rpm / s, the corresponding ordinate values ​​are 20.62rpm·s, 20.33rpm·s, 20.45rpm·s, 20.45rpm·s, and 20.62rpm·s, respectively. The error between the ordinate values ​​is within 0.8%, maintaining a consistent value. Therefore, the average value of 20.495rpm·s can be taken as the area threshold A. This area threshold is applicable to various working conditions and has strong practical applicability.

[0111] Therefore, in the gear meshing judgment model applicable to vehicle X, the value of unit time t is 0.16s, and the value of area threshold A is 20.495rpm·s.

[0112] Figure 8 The diagram shows the waveforms of the first speed of the simulated power source and the first target speed of the gear as a function of shift time when the vehicle X downshifts under stable operating conditions. Although the speed increases when the vehicle downshifts, which is the opposite of the waveform during the upshifting process, the control method used is the same as the control method and calculation method used when the vehicle upshifts, and will not be repeated here.

[0113] In addition, the method of this embodiment is also applicable to the clutch control of an automatic clutch.

[0114] Reference Figures 9-12 To verify the application of the control method of this embodiment to the gear shift control of a certain bus, the following detailed explanation is provided:

[0115] Reference Figure 9 Under stable operating conditions, the waveforms of the first speed of the bus's power source and the first target speed of the gear during acceleration and gear shifting are as follows: Figure 9 As shown, the appropriate gearbox master-slave gear engagement time is approximately 0.42 seconds.

[0116] Based on the parameter tuning method described above, the first area change function is constructed by selecting unit time t1 as 0.05s, 0.10s, 0.15s, 0.20s, 0.25s, and 0.30s. Figure 10 As shown, when the construction conditions are unstable, the second area variation function is as follows: Figure 11 As shown.

[0117] The selection of the range of values ​​per unit time is determined by... Figure 10It can be seen that, in order to avoid the gear meshing timing being in the judgment blind zone at 0.42s, the value range of the unit time should be selected between 0.10s and 0.20s or between 0.25s and 0.30s.

[0118] The specific unit time and area threshold values ​​are determined by... Figure 11 It can be seen that the optimal unit time for this bus is 0.13s, according to... Figure 11 Using a function with a unit time of 0.13 s, the area threshold value can be obtained as 10.53 rpm·s. Therefore, through the above calculations, the area threshold value for the gear meshing judgment model applicable to this bus is 10.53 rpm·s with a unit time of 0.13 s. t b >t a In ≥0, t a to t b The time difference between them is 0.13s. When S≤10.53rpm·s, the master and slave gears of the bus are engaged.

[0119] During actual operation, the bus speed may fluctuate due to road conditions and engine overshoot, affecting gear engagement timing. The waveforms of the power source speed and the target speed of the gear during actual operation are as follows: Figure 12 As shown, the bus begins to shift gears at 0.1s. The master and slave gears at the input and output shafts of the gearbox separate, and the target speed of the gear drops from 2000rpm before the shift to 1400rpm after the shift. Due to road conditions, wheel inertia, and loss of power, the acceleration of the target speed of the gear first increases by 100rpm per second, and then decreases by 200rpm per second after 0.3s, until the master and slave gears of the gearbox mesh.

[0120] Therefore, by Figure 12 It can be seen that, for this situation, the optimal gear engagement time for the bus should be around 0.43s. The optimal unit time, determined through the above calculations, is 0.13s. Based on the bus's power source speed and the target speed of the gear, the first closing time T0 is determined to be 0.2s. That is, at 0.2s, the bus's power source speed and the target speed of the gear are equal. Before time T0, the integral area of ​​the speed error increases; after time T0, the integral area of ​​the speed error begins to decrease. Therefore, starting from 0.2s, according to the formula... Calculate the value of the integral area S, and then use t a to t bSubstituting the unit time t of 0.13s into the formula, when the integral area of ​​the speed error is less than or equal to the set area threshold of 10.53 rpm·s, the current time is determined to be the optimal time for the gearbox master and slave gears to mesh, and the master and slave gears mesh. The meshing time obtained by calculation is 0.439s, and the error between it and the actual optimal meshing time of 0.43s is within 0.01 seconds. Therefore, when the calculation method and gear meshing judgment model of this embodiment are applied to the bus, the connection between the power source and the transmission system can be stabilized, the wear of bus gears can be reduced, smooth shifting can be achieved, and the vehicle driving smoothness can be improved.

[0121] In particular, the simulated changes in vehicle power source speed and gear target speed in Embodiment 1 can be based on the PID control speed regulation method. The PID control speed regulation method is a commonly used speed regulation method for motors / engines, which is similar to the actual changes in vehicle power source speed and gear target speed. The shift control method of this application can be used in practical applications.

[0122] Example 2:

[0123] This embodiment discloses a shift control device for an AMT transmission. The device applies the shift control method described in Embodiment 1. The device includes an information acquisition unit and an engagement control unit.

[0124] An information acquisition unit is used to acquire vehicle operating information in real time during gear shifting; the vehicle operating information includes power source speed and gear target speed.

[0125] The engagement control unit is used to determine the optimal timing for the engagement of the transmission master and slave gears based on the vehicle operating information and a pre-built gear engagement judgment model, and to control the master and slave gears to engage at the optimal timing.

[0126] Example 3:

[0127] This embodiment discloses a terminal, which includes a processor, a memory, and a communication bus. The communication bus is used to realize the connection and communication between the processor and the memory. The processor is used to execute one or more programs stored in the memory to implement the steps of the shift control method as described in Embodiment 1.

[0128] Example 4:

[0129] This embodiment discloses a computer-readable storage medium storing instructions that, when executed, perform the steps of the shift control method as described in Embodiment 1.

[0130] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A shift control method of an AMT transmission, characterized by, The method comprises the following steps: S100: acquiring vehicle operation information in a shifting process in real time; The vehicle operation information comprises power source rotating speed and gear target rotating speed; S200: determining the best timing of main and slave gear engagement of a gearbox based on the vehicle operation information and a pre-constructed gear engagement judgment model, and controlling the main and slave gears to engage at the best timing; The gear engagement judgment model is: wherein E = ω t -ω r , ω t is a gear target speed function representing a correspondence between a gear target speed and a shift time; ω r is a power source speed function representing a correspondence between a power source speed and a shift time; t a is a unit initial time, t b is a unit end time; based on the power source rotational speed function ω r and the gear target rotational speed function ω t , a first closing time T0 is determined; at the time T0, ω r (T0) = ω t (T0); based on the power source rotation speed function ω r , a gear target rotation speed function ω t , the first closing time T0, and the gear engagement judgment model, starting from the time T0, when the area S is less than or equal to the area threshold A, it is determined that the current time is the optimal timing for the master-slave gear engagement of the gearbox, and the master-slave gear engagement is controlled.

2. The shift control method of an AMT transmission according to claim 1, characterized in that: Setting t b -t a The value of the unit time t, when the gear engagement judgment model is constructed, the value of the unit time t and the area threshold A are determined, comprising: S10: acquiring a power source first rotating speed function and a gear first target rotating speed function of a vehicle in a shifting process under stable working condition; the power source first rotating speed function represents the corresponding relationship between power source first rotating speed and shifting time; the gear first target rotating speed function represents the corresponding relationship between gear first target rotating speed and shifting time; S20: determining the first engagement time and the value range of unit time t based on the power source first rotating speed function and the gear first target rotating speed function; S30: acquiring a power source second rotating speed function and a gear second target rotating speed function of a vehicle in a shifting process under unstable working condition; the power source second rotating speed function represents the corresponding relationship between power source second rotating speed and shifting time; the gear second target rotating speed function represents the corresponding relationship between gear second target rotating speed and shifting time; S40: determining the value of unit time t and area threshold A based on the power source second rotating speed function, the gear second target rotating speed function, the first engagement time and the value range of unit time t.

3. The shift control method of an AMT transmission according to claim 2, characterized in that: Step S20 comprises: S21: determining the first engagement time based on the power source first rotating speed function, the gear first target rotating speed function and a plurality of first preset unit times t1, and generating a first area change function corresponding to each first preset unit time t1; the first area change function represents the corresponding relationship between first area and time, and the first area represents the area between the power source first rotating speed function and the gear first target rotating speed function when the unit time t is the first preset unit time t1; S22: determining the value range of unit time t based on the first area change function corresponding to each first preset unit time t1 and the first engagement time.

4. The shift control method of an AMT transmission according to claim 2, characterized in that: Step S40 comprises: S41: selecting a plurality of second preset unit times t2 within the value range of unit time t; S42: generating a second area change function corresponding to each second preset unit time t2 at the first engagement time based on the power source second rotating speed function, the gear second target rotating speed function, the first engagement time and the second preset unit time t2; the second area change function represents the corresponding relationship between second area and the acceleration of gear second target rotating speed, and the second area represents the area between the power source second rotating speed function and the gear second target rotating speed function when the unit time t is the second preset unit time t2; S43: determining the value of unit time t and area threshold A based on the second area change function corresponding to each preset unit time t2; the unit time t is one of the second preset unit times t2.

5. The shift control method of an AMT transmission according to claim 4, characterized in that: The determination process of the area threshold A comprises: selecting a plurality of discrete points from the second area change function corresponding to the unit time t; Determine an average value of the second area set based on the second area set corresponding to the plurality of discrete points; the average value of the second area set is an area threshold A.

6. The shift control method of an AMT transmission according to claim 1, characterized by, The determination process of the area S includes: The time interval from t a to t b is divided into several time sub-intervals; Calculate the area between the power source speed function and the gear target speed function in each time period; Based on the area between the power source rotational speed function and the gear target rotational speed function in each time period, the area S between the power source rotational speed function and the gear target rotational speed function from t a to t b is determined.

7. A shift control device for implementing a shift control method of the AMT transmission according to any one of claims 1 to 6, characterized by: The information acquisition unit is configured to acquire vehicle operation information in real time during the gear shifting process; the vehicle operation information includes power source speed and gear target speed. The engagement control unit is configured to determine the optimal timing of engagement of the master and slave gears of the gearbox based on the vehicle operation information and a pre-constructed gear engagement judgment model, and control the master and slave gears to engage at the optimal timing. The system includes:

8. A terminal, characterized by comprising: A processor, a memory and a communication bus; The communication bus is used to realize the connection communication between the processor and the memory, and the processor is used to execute one or more programs stored in the memory to realize the steps of the gear shifting control method according to any one of claims 1-6. The computer readable storage medium stores instructions which, when executed, perform the steps of the gear shifting control method according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, ​

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