Method and device for improving AMT gear shifting success rate, electronic equipment, readable medium and vehicle

Abstract

The invention relates to a method and device for improving the AMT gear shifting success rate, electronic equipment, a readable medium and a vehicle. The method comprises the steps that before a target gear is combined, the rotating speed of a driving motor and the rotating speed of an output shaft of a target dog tooth are controlled to be kept within a preset slip frequency window; the shifting fork displacement is estimated based on the displacement change rate of the shifting fork after the synchronization starting point, and when the difference value between the estimated displacement and the actual displacement exceeds a preset difference value threshold value, the gear shifting force of a gear shifting motor is increased; and after it is detected that the shifting fork displacement does not reach the synchronization ending point and the gear shifting motor maintains the maximum synchronization force for a first preset duration, the gear shifting motor is controlled to retreat the shifting fork to the synchronization starting point, and synchronization is executed again after the drive motor increases the feedforward torque.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic shift control for pure electric vehicles, and in particular to a method, device, electronic equipment, readable medium and vehicle for improving the success rate of AMT shifting. Background Art

[0002] Commercial electric vehicles usually use an automatic transmission (AMT) to switch between different gears to meet the power requirements under different working conditions. In the prior art, the shifting process of AMT usually adopts the following control scheme: before the target gear is engaged, the control system estimates the slip by detecting the speed and speed change rate on both sides of the dog teeth. When the estimated slip reaches the target window, the drive motor maintains a zero torque or inertia torque state. At the same time, the shift motor adjusts the shift force according to the displacement and rate of the shift fork to push the shift fork to move in the engagement direction. If the shift fork displacement fails to reach the synchronization end point within the preset time, the shift motor will adjust the shift force according to the displacement and rate of the shift fork to move the shift fork in the disengagement direction. When the shift fork returns to the neutral position, the drive motor readjusts the target speed to establish a new shift window and starts a new round of gear engagement operation.

[0003] However, the above control scheme has the following technical problems:

[0004] 1) After the shift motor starts to move the shift fork, the drive motor only maintains the zero torque or inertia torque state, which cannot ensure that the speed difference on both sides of the dog teeth will fall within the slip window when the shift fork reaches the synchronization start point. Since the drive motor basically does not interfere with the speed of the dog teeth input side at this stage, the slip window will change with the change of the output shaft speed. Especially when the vehicle load is large, it is easy to miss the slip window and cause the gear to fail;

[0005] 2) The prior art only judges the gear-entry jam based on the fact that the shift fork displacement has not reached the synchronization end point for a long time. This passive judgment method cannot timely detect the situation of gear-entry jam, and it is also impossible to take measures to overcome the gear-entry resistance in time;

[0006] 3) When the slip difference on both sides of the dog teeth is small, the tooth alignment phenomenon is likely to occur. In this case, only a slight adjustment on the input side of the dog teeth is required to stagger the top teeth and quickly complete the shifting. However, the existing technology lacks such an active adjustment mechanism;

[0007] 4) As the vehicle mileage increases, the gears may wear to varying degrees, resulting in an increase in gear-entry jams; the prior art lacks an adaptive adjustment mechanism for this condition and is unable to improve the success rate of subsequent gear shifts by expanding the slip window and storing it in non-volatile memory (NVRAM).

[0008] Therefore, it is necessary to propose a new control scheme to overcome the above technical problems and improve the shifting reliability and adaptability of AMT of commercial electric vehicles. Summary of the invention

[0009] The present invention discloses a method, a device, an electronic device, a readable medium and a vehicle for improving the success rate of AMT shifting, aiming to solve the technical problems existing in the prior art.

[0010] The present invention adopts the following technical solutions:

[0011] In a first aspect, an embodiment of the present invention provides a method for improving an AMT shift success rate, comprising:

[0012] Before the target gear is engaged, the speed of the drive motor and the output shaft speed of the target dog gear are controlled to remain within a preset slip window;

[0013] The shift fork displacement is estimated based on the displacement change rate of the shift fork after the synchronization start point, and when the difference between the estimated displacement and the actual displacement exceeds a preset difference threshold, the shift force of the shift motor is increased;

[0014] After detecting that the shift fork displacement has not reached the synchronization end point and the shift motor maintains the maximum synchronization force for a first preset time period, the shift motor is controlled to retract the shift fork to the synchronization start point, and re-synchronizes after the drive motor increases the feedforward torque.

[0015] In some embodiments, the step of controlling the rotation speed of the drive motor and the output shaft rotation speed of the target dog gear to remain within a preset slip window includes:

[0016] Get the output shaft speed of the target dog gear;

[0017] Determining a target speed range of the drive motor according to the output shaft speed, wherein the target speed range is defined by the output shaft speed and a preset slip window;

[0018] The rotation speed of the driving motor is adjusted to be within the target rotation speed range and maintained.

[0019] In some embodiments, the step of estimating the displacement of the shift fork based on the displacement change rate of the shift fork after the synchronization start point, and increasing the shift force of the shift motor when the difference between the estimated displacement and the actual displacement exceeds a preset difference threshold, includes:

[0020] Detecting displacement data of the shift fork within a second preset time period after entering the synchronization starting point;

[0021] determining a rate of change of the displacement data;

[0022] Determining an estimated shift fork displacement based on the rate of change and a preset synchronization duration;

[0023] The difference between the estimated fork displacement and the actual fork displacement is compared with a preset difference threshold, and when the difference exceeds the preset threshold, the shifting force of the shifting motor is increased to a preset force value.

[0024] In some embodiments, the step of controlling the shift motor to retract the shift fork to the synchronization starting point includes:

[0025] Control the shift motor to drive the shift fork to move in the disengagement direction with the minimum shifting force;

[0026] detecting the displacement of the shift fork;

[0027] When it is detected that the shift fork displacement reaches the synchronization start point, the shift motor is controlled to maintain zero shift force.

[0028] In some embodiments, the step of re-synchronizing after the drive motor increases the feed-forward torque includes:

[0029] The feedforward torque is superimposed on the speed regulating torque of the driving motor and maintained for a third preset time length;

[0030] After the third preset time period ends, the shift motor is controlled to drive the shift fork to perform a synchronous operation with a maximum synchronous force.

[0031] In some embodiments, it also includes:

[0032] When the shift fork retreats to the synchronization starting point and re-synchronizes, and the synchronization is still not completed after the first preset number of times, the shift motor is controlled to perform the shift disengagement operation;

[0033] Expanding the range value of the preset slip window;

[0034] When it is detected that the dog tooth slip meets the expanded slip window, the shift motor is controlled to re-execute the gear shifting operation.

[0035] In some embodiments, it also includes:

[0036] When synchronization is not completed after the second preset number of re-gear operations are performed, generating target gear position fault information;

[0037] The target gear is disabled until the system is powered on again.

[0038] In a second aspect, an embodiment of the present invention provides a device for improving the success rate of AMT shifting, comprising:

[0039] The speed regulating module is used to control the speed of the drive motor and the output shaft speed of the target dog gear to remain within a preset slip window before the target gear is engaged;

[0040] An estimation module, used for estimating the displacement of the shift fork based on the displacement change rate of the shift fork after the synchronization start point, and increasing the shift force of the shift motor when the difference between the estimated displacement and the actual displacement exceeds a preset difference threshold;

[0041] The synchronization module is used to control the shift motor to retract the shift fork to the synchronization start point after detecting that the shift fork displacement has not reached the synchronization end point and the shift motor maintains the maximum synchronization force for a first preset time period, and re-execute synchronization after the drive motor increases the feedforward torque.

[0042] In a third aspect, an embodiment of the present invention provides an electronic device, including:

[0043] Processor; and

[0044] A memory arranged to store computer executable instructions which, when executed, cause the processor to perform a method as described in any one of the above.

[0045] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores one or more programs, which, when executed by an electronic device including multiple applications, enables the electronic device to execute any of the methods described above.

[0046] In a fifth aspect, an embodiment of the present invention provides a vehicle, comprising a device for improving the success rate of AMT shifting as described in any one of the above items.

[0047] One embodiment of the above invention has the following advantages or beneficial effects:

[0048] The embodiments of the present invention mainly provide a method, device, electronic device, readable medium and vehicle for improving the success rate of AMT gear shifting. Compared with the prior art, the present invention controls the speed of the drive motor to always keep the output shaft speed of the target dog tooth within a preset slip window, thereby ensuring that the slip window will not be missed when the gear shifting motor performs a synchronization operation, and effectively reducing the gear shifting failure caused by the speed difference deviating from the slip window during the dog tooth synchronization process.

[0049] Furthermore, the embodiment of the present invention estimates the displacement of the shift fork by monitoring the displacement change rate of the shift fork after the synchronization start point and compares it with the actual displacement, so as to detect the situation of smooth gear shifting early, increase the shifting force in time to overcome the gear shifting resistance, and significantly shorten the gear shifting time.

[0050] When a gear shift jam is detected, the present invention resynchronizes by retracting the shift fork to the synchronization starting point and cooperating with the drive motor feedforward torque adjustment, which not only avoids the time loss caused by completely returning to the neutral position, but also effectively staggers the speed difference on both sides of the dog teeth through torque intervention, thereby improving the gear shift efficiency. At the same time, for repeated jams caused by gear wear, the present invention improves the adaptability and reliability of the system by adaptively adjusting the slip window and storing related parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments, which constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions explain the present invention and do not constitute improper limitations on the present invention. In the drawings:

[0052] Figure 1 AMT power structure diagram provided for one embodiment of the present invention;

[0053] Figure 2 A flowchart of a method for improving the success rate of AMT shifting provided by one embodiment of the present invention;

[0054] Figure 3 A partial flow chart of a method for improving the success rate of AMT shifting provided by one embodiment of the present invention;

[0055] Figure 4 A partial flow chart of a method for improving the success rate of AMT shifting provided by one embodiment of the present invention;

[0056] Figure 5 A structural block diagram of a device for improving the success rate of AMT shifting provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. In the description of the present invention, it should be noted that the term "or" is usually used in the sense of including "and / or", unless the content clearly indicates otherwise.

[0058] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] In the existing AMT shift control of commercial electric vehicles, the drive motor only maintains a zero torque or inertia torque state after the shift motor starts to move the shift fork, and cannot ensure that the speed difference on both sides of the dog teeth falls within the slip window when the shift fork reaches the synchronization start point, which is easy to cause shift failure especially when the vehicle load is heavy. At the same time, the existing technology only judges the gear engagement jam based on the fact that the shift fork displacement has not reached the synchronization end point for a long time, and cannot promptly detect and deal with the situation of smooth gear engagement. In addition, when the slip difference on both sides of the dog teeth is small, tooth alignment is prone to occur, and there is a lack of effective adaptive adjustment mechanism for the gear engagement jam caused by gear wear after long-term use, which affects the reliability of gear shifting.

[0060] In order to solve the deficiencies in the prior art, the embodiment of the present invention provides a method for improving the success rate of AMT shifting, which is preferably applicable to commercial electric vehicles, including electric trucks, electric buses, electric transport vehicles, electric tractors, etc. Preferably, in the power structure of this embodiment, the drive motor is connected to the two gear boxes through the input shaft, and then to the wheel end through the output shaft. The selection of the speed ratio of the two gear boxes is achieved by controlling the shift motor to move the shift fork, such as Figure 1 .

[0061] refer to Figure 2 In one embodiment of the present invention, the method for improving the AMT shift success rate includes at least steps S110 to S130.

[0062] Step S110: Before the target gear is engaged, the rotation speed of the drive motor and the output shaft rotation speed of the target dog gear are controlled to be within a preset slip window.

[0063] Step S120: estimating the displacement of the shift fork based on the displacement change rate of the shift fork after the synchronization start point, and increasing the shift force of the shift motor when the difference between the estimated displacement and the actual displacement exceeds a preset difference threshold.

[0064] Step S130: after detecting that the shift fork displacement has not reached the synchronization end point and the shift motor maintains the maximum synchronization force for a first preset time period, control the shift motor to retract the shift fork to the synchronization start point, and re-execute synchronization after the drive motor increases the feedforward torque.

[0065] In one embodiment of the present invention, the above steps S110 to S130 are executed by a vehicle controller, which communicates with the drive motor controller and the shift motor controller respectively through the CAN bus, receives feedback signals including output shaft speed, fork displacement, etc., and outputs corresponding control instructions; wherein the drive motor controller is responsible for executing speed regulation and torque control, and the shift motor controller is responsible for executing fork displacement control and shift force regulation, and the three work together to complete the entire shifting process.

[0066] In one embodiment of the present invention, step S110 specifically includes: obtaining the output shaft speed of the target dog teeth, determining the target speed range of the drive motor according to the output shaft speed, and finally adjusting the speed of the drive motor to the target speed range and maintaining it. The target speed range is defined by the output shaft speed and the preset slip window.

[0067] It should be noted that in this embodiment, "slip" refers to the speed difference between the target dog gear input shaft and the output shaft in the AMT. During the shifting process, a suitable slip is conducive to the smooth engagement of the dog gear. The "slip window" refers to the speed difference range that allows the dog gear to engage. When the speed difference on both sides of the dog gear falls within this range, it is conducive to the accurate alignment and smooth engagement of the dog gear.

[0068] Specifically, before the target gear is engaged, the speed sensor collects the speed signal of the target dog gear output shaft in real time. The speed signal may be a pulse signal. The actual speed value of the target dog gear output shaft may be obtained by processing the pulse signal.

[0069] In one embodiment of the present invention, the target speed range of the drive motor is determined based on the obtained output shaft speed and in combination with the preset slip window range. Specifically, if the output shaft speed is n, the upper limit value and the lower limit value of the preset slip window are a and b respectively, then the target speed range of the drive motor is [n+b, n+a]. In a specific embodiment, when the target dog output shaft speed is 1000rpm, the upper limit value and the lower limit value of the preset slip window are 50rpm and 30rpm respectively, then the target speed range of the drive motor is [1030rpm, 1050rpm]. It should be known to those skilled in the art that the slip window is determined based on the specific hardware and is not specifically limited in this embodiment.

[0070] In one embodiment of the present invention, the optimal slip of the target dog teeth is first determined based on the target gear, the oil temperature of the electric drive axle and the slip window, wherein the different target gears will affect the selection of the optimal slip. Since the transmission ratio of the low gear is relatively large, the inertia effect is more significant, and a relatively large slip is required; while a smaller slip can be used for the high gear. The target speed that the drive motor needs to reach can be calculated by the transmission ratio of the target gear. The oil temperature of the electric drive axle will affect the dynamic characteristics of the gear shift. For example, when the oil temperature is low, the oil viscosity is large, and a larger slip is required to overcome the viscous resistance; when the oil temperature rises, the oil viscosity decreases, and a smaller slip can meet the gear shift requirements, so the optimal slip needs to be corrected accordingly. Then, based on the optimal slip determined above, the target speed of the drive motor is determined in combination with the target gear speed. At the same time, the range of the slip window will also restrict the optimal slip. The system will ensure that the optimal slip is always located in the middle area of ​​the slip window to reserve sufficient adjustment margin.

[0071] Then, the VCU determines the speed regulation torque according to the speed regulation target and actual speed and other parameters, and sends it to the MCU for execution. The MCU adjusts the output torque of the drive motor according to the speed regulation torque command. During the speed regulation process, the VCU monitors the speed and its change rate of the drive motor, the speed and its change rate of the output shaft in real time, and estimates whether the target dog tooth slip can enter the dog tooth slip window according to the response time of the shift motor. If it does not enter the slip window, the speed regulation control continues; if it has entered the slip window, the current speed regulation stage is completed.

[0072] Through the above control process, it can be ensured that before the shift motor starts to move the shift fork, the speed difference on both sides of the dog teeth is always appropriate, creating favorable conditions for subsequent synchronous operation. This control strategy is particularly suitable for working conditions with heavy vehicle loads, and can effectively prevent the problem of missing the slip window due to changes in the output shaft speed.

[0073] In one embodiment of the present invention, step S120 specifically includes: detecting the displacement data of the shift fork within a second preset time length after entering the synchronization start point; determining the rate of change of the displacement data; determining the estimated shift fork displacement based on the rate of change and the preset synchronization time length; comparing the difference between the estimated shift fork displacement and the actual shift fork displacement with a preset difference threshold, and when the difference exceeds the preset threshold, increasing the shift force of the shift motor to a preset force value.

[0074] In this embodiment, the "synchronization start point" refers to the initial position of the shift fork when it starts to perform the synchronization operation. When the shift fork moves to the synchronization start point, the shift motor starts to apply a synchronization force, so that the dog teeth gradually approach and engage.

[0075] Specifically, the target dog gear shift force is first determined based on the displacement of the shift fork and its rate of change. When the shift fork enters the synchronization start point, the TCU controls the shift motor to execute according to the shift force. At the same time, the VCU determines the appropriate synchronization force based on the operating parameters such as the oil temperature of the electric drive axle, and controls the shift motor to execute through the TCU.

[0076] Specifically, the oil temperature of the electric drive axle directly determines the required synchronization force by affecting the lubrication state and friction characteristics between the gears. In one embodiment of the present invention, a correction coefficient of the synchronization force can be established based on the oil temperature. When the oil temperature is low, due to the high viscosity of the oil, a larger synchronization force is required, and the correction coefficient can reach 1.2-1.3; when the oil temperature is within the normal working range, the correction coefficient remains at about 1.0; when the oil temperature is too high, due to the significant decrease in oil viscosity, the synchronization force needs to be appropriately increased to compensate for the decrease in lubrication effect, and the correction coefficient can reach 1.1-1.2.

[0077] The product of the correction coefficient and the reference synchronizing force is the actual synchronizing force. The reference synchronizing force is usually pre-calibrated based on factors such as different gears and vehicle loads. This adaptive adjustment strategy can ensure good shifting quality under different oil temperature conditions.

[0078] In terms of shift fork displacement monitoring, the shift fork displacement data is first detected within the second preset time period (for example, 50ms) after entering the synchronization start point. By calculating the rate of change of the shift fork displacement during this period and combining it with the preset synchronization time, the VCU can estimate the displacement trajectory of the shift fork under the current shift force.

[0079] If the difference between the estimated fork displacement and the actual detected fork displacement exceeds the preset difference threshold, it indicates that the current shift force may not be sufficient to overcome the synchronization resistance. In some embodiments, the preset difference threshold is 1 mm. At this time, the VCU will instruct the TCU to increase the shift force of the shift motor to the preset force value to ensure the smooth completion of the synchronization operation.

[0080] Through this control strategy based on displacement estimation, the system can promptly detect and handle abnormal situations during the synchronization process and improve the reliability of gear shifting.

[0081] In one embodiment of the present invention, in step S130, after detecting that the displacement of the shift fork has not reached the synchronization end point and the shift motor maintains the maximum synchronization force for a first preset time period, a supplementary operation is performed. In the supplementary operation, the shift motor is first controlled to drive the shift fork to move in the disengagement direction with the minimum shifting force, and the displacement of the shift fork is detected. When it is detected that the shift fork displacement reaches the synchronization start point, the shift motor is controlled to maintain zero shifting force; then, the feedforward torque is superimposed on the speed regulation torque of the drive motor, and maintained for a third preset time period. After the third preset time period ends, the shift motor is controlled to drive the shift fork with the maximum synchronization force to perform the synchronization operation.

[0082] Specifically, when the target dog teeth are synchronized, when the slip difference on both sides of the dog teeth tends to be stable and enters the slip dead zone, it is easy to get stuck. At this time, even if the synchronization force is increased, synchronization cannot be completed. Among them, the "slip dead zone" refers to the area where the speed difference on both sides of the dog teeth is in a certain range, although the speed difference is small, it is difficult to complete the engagement. This phenomenon usually occurs when the speed difference is close but not completely matched, and the dog teeth are prone to tooth matching.

[0083] When it is detected that the shift fork displacement fails to reach the synchronization end point and the shift motor has maintained the maximum synchronization force (e.g., 20 Nm) for a first preset time (e.g., 50 ms), it is determined that the current synchronization process may have become stuck and a supplementary operation is performed.

[0084] During the re-engagement operation, the TCU controls the shift motor to drive the shift fork to move in the disengagement direction with the minimum shifting force (about 10-20Nm). At this time, the shift fork displacement is continuously monitored, and when the shift fork returns to the synchronization starting point, the shift motor is controlled to maintain a zero shift force state.

[0085] Then, to avoid entering the slip dead zone again, the VCU superimposes a feedforward torque on the original speed regulating torque of the drive motor. The direction of this feedforward torque is based on the final torque estimation value of the drive motor, and the purpose is to make the speed difference on both sides of the dog teeth avoid the slip dead zone through active torque intervention. The system maintains the feedforward torque for a third preset time, which is preferably 50ms.

[0086] After the third preset time period, the TCU controls the shift motor to drive the shift fork to perform synchronization operation with the maximum synchronization force again, and tries to complete the shift process. If the process is still unsuccessful and does not exceed the first preset number of times, the above-mentioned re-engagement process is repeated; if it exceeds the preset number of times, the subsequent abnormality handling process is entered. Preferably, the first preset number of times can be set to 3 times.

[0087] Through the control of the above embodiment, the gear shifting jamming problem caused by the slip dead zone can be effectively solved through the coordination of local gear downshifting and torque intervention.

[0088] like Figure 3 In one embodiment of the present invention, the method further includes steps S210 to S230.

[0089] Step S210: When the shift fork retreats to the synchronization starting point and re-executes synchronization, and the synchronization is still not completed after a first preset number of times, the shift motor is controlled to perform a shift-off operation.

[0090] Specifically, when the shift fork still fails to complete synchronization after a first preset number of re-engagement operations, the system determines that the shift abnormality may be caused by gear wear or other long-term factors.

[0091] In one embodiment of the present invention, the shift fork retraction force and retraction time are determined according to the oil temperature of the electric drive axle and the temperature of the shift motor. The TCU controls the shift motor to perform the shifting operation according to the set retraction force until the retraction time reaches the preset retraction time. When the retraction time of the shift motor exceeds the retraction time, the shift motor is controlled to maintain a zero shift force state.

[0092] Step S220: Expand the range of the preset sliding window.

[0093] In one embodiment of the present invention, after the original slip window range is expanded, the expanded parameters are stored in a non-volatile memory (NVRAM). This adaptive adjustment can compensate for changes in synchronization characteristics caused by gear wear. Optionally, the upper limit of the slip window when expanded is 150rpm.

[0094] Step S230: When it is detected that the dog tooth slip meets the enlarged slip window, the shift motor is controlled to re-execute the gear shifting operation.

[0095] In one embodiment of the present invention, the compensation torque and the compensation time of the drive motor are determined according to the target gear position and the oil temperature of the electric drive axle. On the basis of adjusting the speed of the drive motor, the compensation torque is increased and executed. When the execution compensation time exceeds the compensation time, the system detects whether the dog tooth slip meets the expanded slip window requirement. If the requirement is met, the shift motor is controlled to re-execute the gear shifting operation; if the requirement is not met, the compensation torque adjustment is continued until the condition is met or the control limit is reached.

[0096] In one embodiment of the present invention, a reference compensation torque value is set based on the target gear. The reference compensation torque value is larger in the low gear due to the large transmission ratio, and is correspondingly reduced in the high gear. At the same time, corrections are made according to the oil temperature of the electric drive axle. The compensation torque needs to be appropriately increased at low and high temperatures, and is linearly adjusted according to the oil temperature at normal temperature.

[0097] In one embodiment of the present invention, a reference torque compensation time is set based on the target gear, the torque compensation time is longer in low gear and shorter in high gear; at the same time, correction is made according to the oil temperature, the torque compensation time is appropriately extended at low temperature, slightly extended at high temperature, and the reference value is maintained at normal temperature.

[0098] In the above embodiment, the system's adaptability to long-term changing factors such as gear wear is improved by expanding the slip window and adjusting the compensation torque. At the same time, the adjusted parameters are stored in a non-volatile memory to ensure that these optimized parameters are still valid after the vehicle is restarted, thereby improving the reliability and adaptability of the shifting system.

[0099] like Figure 4 In one embodiment of the present invention, the method further includes steps S310 to S320.

[0100] Step S310: When synchronization is not completed after the second preset number of re-shifting operations are performed, target gear position fault information is generated.

[0101] In one embodiment of the present invention, the second preset number of times is 6 times. When the above steps S210 to S230 have been executed for this number of times and still the synchronization cannot be completed, it indicates that the target gear may have mechanical faults such as severe wear.

[0102] Step S320: disabling the target gear until the system is powered on again.

[0103] In one embodiment of the present invention, the gear disengagement force is determined according to the oil temperature of the electric drive axle and the temperature of the gear shift motor, and the gear shift motor is controlled to perform the gear disengagement operation. When the shift fork moves to the gear disengagement position, it is detected whether the slip window of the target dog tooth is less than a preset threshold. If it is less than the threshold, the target gear position fault information is generated.

[0104] Next, the slip window of the target dog gear is increased according to the number of dog gear engagement jams, and the enlarged parameters are recorded in NVRAM. These parameters will serve as a sign that the gear is faulty; finally, the target gear is disabled and no gear shifting is performed using the gear until the system is powered on again.

[0105] Through the above processing, wear of the gear shift system caused by repeated attempts can be avoided, and a basis can be provided for subsequent fault diagnosis.

[0106] like Figure 5 In one embodiment of the present invention, a device 400 for improving the success rate of AMT shifting is also provided. The device at least includes a speed adjustment module 410, an estimation module 420 and a synchronization module 430.

[0107] In one embodiment of the present invention, the speed regulating module 410 is used to control the speed of the drive motor and the output shaft speed of the target dog gear to remain within a preset slip window before the target gear is engaged.

[0108] In one embodiment of the present invention, the speed adjustment module 410 is further used to obtain the output shaft speed of the target dog gear, determine the target speed range of the drive motor according to the output shaft speed, and finally adjust the speed of the drive motor to the target speed range and maintain it. The target speed range is defined by the output shaft speed and the preset slip window.

[0109] In one embodiment of the present invention, the estimation module 420 is used to estimate the displacement of the shift fork based on the displacement change rate of the shift fork after the synchronization start point, and increase the shift force of the shift motor when the difference between the estimated displacement and the actual displacement exceeds a preset difference threshold.

[0110] In one embodiment of the present invention, the estimation module 420 is also used to detect the displacement data of the shift fork within a second preset time period after entering the synchronization start point; determine the change rate of the displacement data; determine the estimated shift fork displacement based on the change rate and the preset synchronization time period; compare the difference between the estimated shift fork displacement and the actual shift fork displacement with a preset difference threshold, and when the difference exceeds the preset threshold, increase the shift force of the shift motor to a preset force value.

[0111] In one embodiment of the present invention, the synchronization module 430 is used to control the shift motor to retract the shift fork to the synchronization start point after detecting that the shift fork displacement has not reached the synchronization end point and the shift motor maintains the maximum synchronization force for a first preset time period, and re-execute synchronization after the drive motor increases the feedforward torque.

[0112] In one embodiment of the invention, the synchronization module 430 is also used to detect that the displacement of the shift fork has not reached the synchronization end point, and the shift motor maintains the maximum synchronization force for a first preset time period, and then performs a supplementary operation. In the supplementary operation, the shift motor is first controlled to drive the shift fork to move in the disengagement direction with the minimum shifting force, and the displacement of the shift fork is detected. When it is detected that the shift fork displacement reaches the synchronization start point, the shift motor is controlled to maintain zero shifting force; then, the feedforward torque is superimposed on the speed regulation torque of the drive motor, and maintained for a third preset time period. After the third preset time period ends, the shift motor is controlled to drive the shift fork with the maximum synchronization force to perform the synchronization operation.

[0113] In one embodiment of the present invention, the device 400 for improving the success rate of AMT shifting further includes a re-engagement module 440 and a gear disabling module 450 .

[0114] In one embodiment of the present invention, the re-engagement module 440 is used to control the shift motor to perform a gear disengagement operation when the shift fork retreats to the synchronization start point and the synchronization is not completed after a first preset number of times; then the range value of the preset slip window is expanded; when it is detected that the dog tooth slip meets the expanded slip window, the shift motor is controlled to re-execute the gear engagement operation.

[0115] In one embodiment of the present invention, the gear disabling module 450 is used to generate target gear fault information when synchronization is not completed after executing the second preset number of re-gear operations; and disable the target gear until the system is powered on again.

[0116] It should be noted that the device for improving the AMT shift success rate provided in the above-mentioned embodiment and the embodiment of the method for improving the AMT shift success rate belong to the same concept, and the specific implementation process is detailed in the embodiment of the control method, which will not be repeated here.

[0117] In one embodiment of the present invention, a commercial electric vehicle is provided. The vehicle is provided with the above-mentioned device 200 for improving the success rate of AMT shifting and is capable of executing the above-mentioned shifting overlap control method.

[0118] The embodiment of the present invention further provides an electronic device, which includes a memory and a processor, wherein a computer program executed by the processor is stored in the memory, and when the computer program is executed by the processor, the processor executes the method for improving the success rate of AMT shifting in the foregoing text. Various applications and various data may also be stored in the memory, such as various data used and / or generated by the application. The processor may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other forms of processing units having data processing capabilities and / or instruction execution capabilities.

[0119] The embodiment of the present invention further provides a computer-readable storage medium, on which a computer program executed by a processor is stored. When the computer program is executed by the processor, the processor executes the method for improving the success rate of AMT shifting as described above. Exemplarily, the computer storage medium may include a memory card of a smart phone, a storage component of a tablet computer, a hard disk of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disk read-only memory (CD-ROM), a USB memory, or any combination of the above storage media. The computer-readable storage medium may be any combination of one or more computer-readable storage media.

[0120] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present application to this. Those of ordinary skill in the art may make various changes and modifications therein without departing from the scope and spirit of the present application. All these changes and modifications are intended to be included within the scope of the present application as required by the appended claims.

[0121] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0122] Similarly, it should be understood that in order to streamline the present application and help understand one or more of the various inventive aspects, in the description of the exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present application should not be interpreted as reflecting the following intention: the claimed application requires more features than the features clearly stated in each claim. More specifically, as reflected in the corresponding claims, the inventive point is that the corresponding technical problem can be solved with features less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are hereby explicitly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present application.

[0123] It will be understood by those skilled in the art that, except for mutually exclusive features, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this specification may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0124] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A method for improving the success rate of AMT shifting, characterized in that: include: Before the target gear is engaged, the speed of the drive motor and the output shaft speed of the target dog gear are controlled to remain within a preset slip window; The shift fork displacement is estimated based on the displacement change rate of the shift fork after the synchronization start point, and when the difference between the estimated displacement and the actual displacement exceeds a preset difference threshold, the shift force of the shift motor is increased; After detecting that the shift fork displacement has not reached the synchronization end point and the shift motor maintains the maximum synchronization force for a first preset time period, the shift motor is controlled to retract the shift fork to the synchronization start point, and re-synchronizes after the drive motor increases the feedforward torque.

2. The method for improving the AMT shift success rate according to claim 1, characterized in that: The step of controlling the rotation speed of the driving motor and the output shaft rotation speed of the target dog teeth to remain within a preset slip window includes: Get the output shaft speed of the target dog gear; Determining a target speed range of the drive motor according to the output shaft speed, wherein the target speed range is defined by the output shaft speed and a preset slip window; The rotation speed of the driving motor is adjusted to be within the target rotation speed range and maintained.

3. The method for improving the AMT shift success rate according to claim 1, characterized in that: The step of estimating the displacement of the shift fork based on the displacement change rate of the shift fork after the synchronization start point, and increasing the shift force of the shift motor when the difference between the estimated displacement and the actual displacement exceeds a preset difference threshold, includes: Detecting displacement data of the shift fork within a second preset time period after entering the synchronization starting point; determining a rate of change of the displacement data; Determining an estimated shift fork displacement based on the rate of change and a preset synchronization duration; The difference between the estimated fork displacement and the actual fork displacement is compared with a preset difference threshold, and when the difference exceeds the preset threshold, the shifting force of the shifting motor is increased to a preset force value.

4. The method for improving the AMT shift success rate according to claim 1, characterized in that: The step of controlling the shift motor to retract the shift fork to the synchronization starting point includes: Control the shift motor to drive the shift fork to move in the disengagement direction with the minimum shifting force; detecting the displacement of the shift fork; When it is detected that the shift fork displacement reaches the synchronization start point, the shift motor is controlled to maintain zero shift force.

5. The method for improving the AMT shift success rate according to claim 1, characterized in that: The step of re-synchronizing after the drive motor increases the feed-forward torque includes: The feedforward torque is superimposed on the speed regulating torque of the driving motor and maintained for a third preset time length; After the third preset time period ends, the shift motor is controlled to drive the shift fork to perform a synchronous operation with a maximum synchronous force.

6. The method for improving the AMT shift success rate according to claim 1, characterized in that: Also includes: When the shift fork retreats to the synchronization starting point and re-synchronizes, and the synchronization is still not completed after the first preset number of times, the shift motor is controlled to perform the shift disengagement operation; Expanding the range value of the preset slip window; When it is detected that the dog tooth slip meets the expanded slip window, the shift motor is controlled to re-execute the gear shifting operation.

7. The method for improving the AMT shift success rate according to claim 6, characterized in that: Also includes: When synchronization is not completed after the second preset number of re-gear operations are performed, generating target gear position fault information; The target gear is disabled until the system is powered on again.

8. A device for improving the success rate of AMT shifting, characterized in that: include: The speed regulating module is used to control the speed of the drive motor and the output shaft speed of the target dog gear to remain within a preset slip window before the target gear is engaged; An estimation module, used for estimating the displacement of the shift fork based on the displacement change rate of the shift fork after the synchronization start point, and increasing the shift force of the shift motor when the difference between the estimated displacement and the actual displacement exceeds a preset difference threshold; The synchronization module is used to control the shift motor to retract the shift fork to the synchronization start point after detecting that the shift fork displacement has not reached the synchronization end point and the shift motor maintains the maximum synchronization force for a first preset time period, and re-execute synchronization after the drive motor increases the feedforward torque.

9. An electronic device, characterized in that: include: processor; as well as A memory arranged to store computer executable instructions, which when executed cause the processor to perform a method as claimed in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores one or more programs, which, when executed by an electronic device including a plurality of application programs, enable the electronic device to execute the method according to any one of claims 1 to 7.

11. A vehicle, characterized in that: Including the device for improving the AMT shift success rate as described in claim 8.

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