Methods, devices, electronic equipment, readable media, and vehicles for improving AMT shift success rate

Abstract

This invention relates to a method, apparatus, electronic device, readable medium, and vehicle for improving the success rate of AMT (Automated Manual Transmission) gear shifting. The method includes: before engaging the target gear, controlling the rotational speed of the drive motor to remain within a preset slip window relative to the output shaft rotational speed of the target gear; estimating the shift fork displacement based on the rate of change of displacement of the shift fork after the synchronization start point; increasing the shifting force of the shift motor when the difference between the estimated displacement and the actual displacement exceeds a preset difference threshold; and after detecting that the shift fork displacement has not reached the synchronization end point and the shift motor maintains maximum synchronization force for a first preset duration, controlling the shift motor to retract the shift fork to the synchronization start point, and re-performing synchronization after increasing feedforward torque in the drive motor.

Description

Technical Field

[0001] This invention relates to the field of automatic gear shifting control technology for pure electric vehicles, and in particular to a method, apparatus, electronic device, readable medium, and vehicle for improving the success rate of AMT gear shifting. Background Technology

[0002] Commercial electric vehicles typically employ automated manual transmissions (AMTs) to switch between different gears to meet power demands under varying operating conditions. In existing technologies, the shifting process of an AMT usually employs the following control scheme: Before engaging the target gear, the control system estimates the slip by detecting the rotational speed and rate of change of the shift lever on both sides. When the estimated slip reaches the target window, the drive motor maintains zero torque or inertial torque, while the shift motor adjusts the engagement force based on the shift fork displacement and speed, pushing the shift fork towards the engagement direction. If the shift fork displacement fails to reach the synchronization endpoint within a preset time, the shift motor adjusts the disengagement force based on the shift fork displacement and speed, causing the shift fork to move towards the disengagement direction. Once the shift fork returns to the neutral position, the drive motor readjusts the target speed to establish a new shift window and begins a new round of gear engagement.

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

[0004] 1) After the shift motor starts moving the shift fork, the drive motor only maintains a zero torque or inertial torque state. This cannot guarantee that the speed difference on both sides of the dog tooth 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 tooth input side at this stage, the slip window will change with the speed of the output shaft. Especially when the vehicle load is large, it is easy to miss the slip window and cause the shift to fail.

[0005] 2) Existing technology judges gear engagement sticking only 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 detect the situation of unsmooth gear engagement in time, and therefore cannot take timely measures to overcome the gear engagement resistance.

[0006] 3) When the slip difference between the two sides of the dog tooth is small, the tooth-to-tooth phenomenon is likely to occur. In this case, a slight adjustment to the input side of the dog tooth may be needed to avoid the tooth tipping and quickly complete the shifting. However, the existing technology lacks such an active adjustment mechanism.

[0007] 4) As vehicle mileage increases, gears may wear to varying degrees, leading to more frequent gear shifting problems. Existing technology lacks an adaptive adjustment mechanism for this situation and cannot improve the success rate of subsequent gear shifts by expanding the slip window and storing it in non-volatile memory (NVRAM).

[0008] Therefore, a new control scheme is needed to overcome the above-mentioned technical problems and improve the shifting reliability and adaptability of AMT in commercial electric vehicles. Summary of the Invention

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

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

[0011] In a first aspect, embodiments of the present invention provide a method for improving the shift success rate of an automatic transmission (AMT), comprising:

[0012] Before engaging the target gear, the speed of the control drive motor and the output shaft speed of the target dog gear are kept within a preset slip window;

[0013] The shift fork displacement is estimated based on the rate of change of displacement of the shift fork after the synchronization start point. When the difference between the estimated displacement and the actual displacement exceeds the preset difference threshold, the shifting 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, the shift motor is controlled to return the shift fork to the synchronization start point, and synchronization is re-executed after the drive motor increases the feedforward torque.

[0015] In some embodiments, the step of maintaining the rotational speed of the drive motor and the output shaft rotational speed of the target dog tooth within a preset slip window includes:

[0016] Obtain the output shaft speed of the target dog tooth;

[0017] The target speed range of the drive motor is determined based on the output shaft speed, wherein the target speed range is jointly limited by the output shaft speed and a preset slip window;

[0018] Adjust the speed of the drive motor to the target speed range and maintain it.

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

[0020] Detect the displacement data of the shift fork within the second preset time after entering the synchronization start point;

[0021] Determine the rate of change of the displacement data;

[0022] Based on the rate of change and the preset synchronization duration, the estimated shift fork displacement is determined;

[0023] The difference between the estimated shift fork displacement and the actual shift fork displacement is compared with a preset difference threshold. When the difference exceeds the preset threshold, the shifting force of the shift 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 start point includes:

[0025] The shift motor is controlled to drive the shift fork to move in the disengagement direction with minimal disengagement force.

[0026] Detect the displacement of the shift fork;

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

[0028] In some embodiments, the step of re-performing synchronization after the drive motor increases feedforward torque includes:

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

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

[0031] In some embodiments, it also includes:

[0032] When the shift fork returns to the synchronization start point and synchronization is re-executed, if synchronization is still not completed after the first preset number of times, the shift motor is controlled to perform a disengagement operation.

[0033] Expand the range of the preset slip window;

[0034] When the dog tooth slip is detected to meet the expanded slip window, the shift motor is controlled to re-execute the gear engagement operation.

[0035] In some embodiments, it also includes:

[0036] If synchronization is not completed after performing the second preset number of re-gear shifting operations, a target gear fault message is generated.

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

[0038] Secondly, embodiments of the present invention provide an apparatus for improving the success rate of AMT gear shifting, comprising:

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

[0040] The estimation module is used to estimate the displacement of the shift fork based on the rate of change of displacement of the shift fork after the synchronization start point. When the difference between the estimated displacement and the actual displacement exceeds the preset difference threshold, the shifting force of the shift motor is increased.

[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, and then re-executes synchronization after the drive motor increases the feedforward torque.

[0042] Thirdly, embodiments of the present invention provide an electronic device, including:

[0043] Processor; and

[0044] A memory configured to store computer-executable instructions, which, when executed, cause the processor to perform the method described in any of the preceding methods.

[0045] Fourthly, embodiments of the present invention provide 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, cause the electronic device to perform the method described in any of the preceding claims.

[0046] Fifthly, embodiments of the present invention provide a vehicle that includes the apparatus for improving the shift success rate of an AMT as described in any of the preceding claims.

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

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

[0049] Furthermore, in this embodiment of the invention, the displacement of the shift fork is estimated by monitoring the rate of change of displacement of the shift fork after the synchronization start point, and compared with the actual displacement. This allows for early detection of unsmooth gear shifting, timely increase of shifting force to overcome gear shifting resistance, and significant reduction of shifting time.

[0050] When shifting jam is detected, this invention resynchronizes the shift fork by returning it to the synchronization start point and adjusting the feedforward torque of the drive motor. This avoids the time loss caused by completely returning to neutral and effectively offsets the speed difference on both sides of the dog tooth through torque intervention, thus improving shifting efficiency. Furthermore, for repeated jamming caused by gear wear, this invention improves the system's adaptability and reliability by adaptively adjusting the slip window and storing relevant parameters. Attached Figure Description

[0051] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below, forming part of the present invention. The illustrative embodiments of the present invention and their descriptions explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

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

[0053] Figure 2 A flowchart illustrating a method for improving the shift success rate of an AMT (Automated Manual Transmission) according to an embodiment of the present invention;

[0054] Figure 3 This is a partial flowchart of a method for improving the shift success rate of an AMT (Automated Manual Transmission) according to an embodiment of the present invention;

[0055] Figure 4 This is a partial flowchart of a method for improving the shift success rate of an AMT (Automated Manual Transmission) according to an embodiment of the present invention;

[0056] Figure 5 This is a structural block diagram of a device for improving the success rate of AMT gear shifting, provided in one embodiment of the present invention. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. In the description of this invention, it should be noted that the term "or" is generally used to include the meaning of "and / or," unless otherwise expressly indicated.

[0058] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0059] In existing AMT shift control systems for commercial electric vehicles, the drive motor maintains only a zero torque or inertial torque state after the shift motor begins to move the shift fork. This cannot ensure that the speed difference between the two sides of the dog teeth falls within the slip window when the shift fork reaches the synchronization start point, which can easily lead to shift failure, especially when the vehicle load is large. At the same time, the existing technology only judges shift jamming based on the shift fork displacement not reaching the synchronization end point for a long time, which cannot detect and deal with the situation of unsmooth shifting in time. In addition, when the slip difference between the two sides of the dog teeth is small, tooth misalignment is prone to occur, and there is no effective adaptive adjustment mechanism for shift jamming caused by gear wear after long-term use, which affects the reliability of shifting.

[0060] To address the shortcomings of existing technologies, this invention provides a method for improving the success rate of AMT (Automated Manual Transmission) gear shifting. This method is preferably applicable to commercial electric vehicles, including electric trucks, electric buses, electric transport vehicles, and electric tractors. Preferably, in the power structure of this embodiment, the drive motor is connected to two gearboxes via an input shaft, and then to the wheel ends via an output shaft. The selection of the gearbox speed ratio is achieved by controlling the movement of the shift fork of the shift motor, such as... Figure 1 .

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

[0062] Step S110: Before engaging the target gear, control the speed of the drive motor and the output shaft speed of the target dog tooth to remain within the preset slip window.

[0063] Step S120: Estimate the shift fork displacement based on the displacement change rate of the shift fork after the synchronization start point. When the difference between the estimated displacement and the actual displacement exceeds the preset difference threshold, increase the shifting force of the shift motor.

[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, control the shift motor to return 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, steps S110 to S130 are executed by the vehicle controller. The vehicle controller communicates with the drive motor controller and the shift motor controller via the CAN bus, respectively, receives feedback signals including output shaft speed and shift fork displacement, and outputs corresponding control commands. The drive motor controller is responsible for performing speed adjustment and torque control, and the shift motor controller is responsible for performing shift fork displacement control and shift force adjustment. 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 tooth, determining the target speed range of the drive motor based on the output shaft speed, and finally adjusting the speed of the drive motor to and maintaining it within the target speed range. The target speed range is defined by both the output shaft speed and a preset slip window.

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

[0068] Specifically, before engaging the target gear, the rotational speed signal of the target dog-tooth output shaft is acquired in real time by a speed sensor. This rotational speed signal can be a pulse signal, and the actual rotational speed value of the target dog-tooth output shaft can 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 acquired output shaft speed and a preset slip window range. Specifically, if the output shaft speed is n, and the upper and lower limits 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-tooth output shaft speed is 1000 rpm, and the upper and lower limits of the preset slip window are 50 rpm and 30 rpm respectively, the target speed range of the drive motor is [1030 rpm, 1050 rpm]. Those skilled in the art should understand that the slip window is determined based on specific hardware and is not specifically limited in this embodiment.

[0070] In one embodiment of the invention, the optimal slip for the target gear is first determined based on the target gear, the oil temperature of the electric drive axle, and the slip window. The target gear affects the selection of the optimal slip; lower gears, due to their larger transmission ratio, are more significantly affected by inertia and require a relatively larger slip, while higher gears can use a smaller slip. The target speed of the drive motor can be calculated using the transmission ratio of the target gear. The oil temperature of the electric drive axle affects the dynamic characteristics of gear shifting. For example, when the oil temperature is low, the oil viscosity is high, requiring a larger slip to overcome viscous resistance; when the oil temperature rises, the oil viscosity decreases, and a smaller slip is sufficient for gear shifting. Therefore, the optimal slip needs to be corrected accordingly. Next, based on the determined optimal slip and the target gear speed, the target speed of the drive motor is determined. Simultaneously, the range of the slip window also constrains the optimal slip. The system ensures that the optimal slip is always located in the middle region of the slip window to allow for sufficient adjustment margin.

[0071] Then, the VCU determines the speed regulation torque based on parameters such as the speed regulation target and the actual speed, 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 of the drive motor and its rate of change, the speed of the output shaft and its rate of change in real time, and estimates whether the slip of the target dog tooth can enter the dog tooth slip window based on 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 an appropriate speed difference is maintained on both sides of the dog tooth before the shift motor begins to move the shift fork, creating favorable conditions for subsequent synchronization operations. This control strategy is particularly suitable for operating conditions with heavy vehicle loads, and can effectively prevent the problem of missing the slip window due to changes in 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 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; comparing the difference between the estimated shift fork displacement and the actual shift fork displacement with a preset difference threshold; and increasing the shifting force of the shift motor to a preset force value when the difference exceeds the preset threshold.

[0074] In this embodiment, the "synchronization start point" refers to the initial position when the shift fork begins to perform the synchronization operation. When the shift fork moves to the synchronization start point, the shift motor begins to apply a synchronizing force, causing the gear teeth to gradually approach and engage.

[0075] Specifically, the shifting force of the target dog tooth 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 shifting force. At the same time, the VCU determines the appropriate synchronization force based on operating parameters such as the oil temperature of the electric drive axle, and controls the shift motor to execute it through the TCU.

[0076] Specifically, the oil temperature of the electric drive axle directly determines the required synchronizing force by affecting the lubrication state and friction characteristics between gears. In one embodiment of the present invention, a correction coefficient for the synchronizing force can be established based on the oil temperature. When the oil temperature is low, a larger synchronizing force is required due to the high viscosity of the oil, and the correction coefficient can reach 1.2-1.3. When the oil temperature is within the normal operating range, the correction coefficient remains at around 1.0. When the oil temperature is too high, the oil viscosity decreases significantly, and the synchronizing 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 factor and the reference synchronizing force is the actual synchronizing force applied. The reference synchronizing force is usually pre-calibrated based on factors such as different gears and vehicle load. This adaptive adjustment strategy ensures good shifting quality under different oil temperature conditions.

[0078] Regarding shift fork displacement monitoring, the displacement data of the shift fork is first detected within a second preset time period (e.g., 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 predict the displacement trajectory of the shift fork under the current shifting force.

[0079] If the difference between the estimated shift fork displacement and the actual detected shift fork displacement exceeds a preset difference threshold, it indicates that the current shifting force may be insufficient to overcome the synchronous resistance. In some embodiments, the preset difference threshold is 1 mm. At this time, the VCU will instruct the TCU to increase the shifting force of the shifting motor to the preset force value to ensure the smooth completion of the synchronous operation.

[0080] By employing this displacement-prediction-based control strategy, the system can promptly detect and handle abnormal situations during synchronization, thereby improving the reliability of gear shifting.

[0081] In one embodiment of the present invention, in 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, a supplementary engagement operation is performed. In the supplementary engagement operation, the shift motor is first controlled to drive the shift fork to move in the disengagement direction with the minimum disengagement force, and the displacement of the shift fork is detected. When the shift fork displacement is detected to reach the synchronization start point, the shift motor is controlled to maintain zero shift force. Then, a feedforward torque is superimposed on the speed regulation torque of the drive motor and maintained for a third preset time. After the third preset time ends, the shift motor is controlled to drive the shift fork to perform the synchronization operation with the maximum synchronization force.

[0082] Specifically, during synchronization, when the slip difference on both sides of the target dog tooth stabilizes and enters the slip dead zone, jamming can easily occur. At this point, even increasing the synchronization force cannot achieve synchronization. The "slip dead zone" refers to the area where, although the speed difference on both sides of the dog tooth is small, engagement is difficult to achieve when the speed difference is within a certain range. This phenomenon typically occurs when the speed differences are close but not fully matched, at which point the dog tooth is prone to misalignment.

[0083] When it is detected that the shift fork displacement has failed 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 stalled, and a supplementary shifting operation is performed.

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

[0085] Then, to avoid re-entering the slip dead zone, the VCU adds a feedforward torque to the original speed regulating torque of the drive motor. The direction of this feedforward torque is based on the final torque estimate of the drive motor, and its purpose is to use active torque intervention to ensure that the speed difference on both sides of the dog tooth avoids the slip dead zone. The system maintains this feedforward torque for a third preset duration, preferably 50ms.

[0086] After the third preset time period ends, the TCU controls the shift motor to drive the shift fork again with maximum synchronous force to perform synchronous operation and attempt to complete the shifting process. If the process is still unsuccessful and has not exceeded the first preset number of times, the above-mentioned re-engagement process is repeated; if the preset number of times is exceeded, the subsequent abnormal handling process is initiated. Preferably, the first preset number of times can be set to 3 times.

[0087] Through the control described in the above embodiments, the problem of shifting sticking caused by slip dead zone can be effectively addressed by combining partial downshifting and torque intervention.

[0088] like Figure 3 In one embodiment of the present invention, steps S210 to S230 are also included.

[0089] Step S210: When the shift fork returns to the synchronization start point and synchronization is re-executed, if synchronization is still not completed after the first preset number of times, control the shift motor to perform the disengagement operation.

[0090] Specifically, if the shift fork fails to achieve synchronization after the first preset number of re-engagement operations, the system determines that the shifting abnormality may be due to gear wear or other long-term factors.

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

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

[0093] In one embodiment of the invention, after expanding the original slip window range, the expanded parameter is stored in 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 150 rpm.

[0094] Step S230: When the dog tooth slip is detected to meet the expanded slip window, control the shift motor to re-execute the shifting operation.

[0095] In one embodiment of the present invention, the compensation torque and compensation duration of the drive motor are determined based on the target gear and the oil temperature of the electric drive axle. Based on the adjusted speed of the drive motor, the compensation torque is increased and executed. When the compensation time exceeds the compensation duration, the system checks whether the dog-tooth slip meets the requirements of the expanded slip window. If the requirements are met, the shift motor is controlled to re-execute the gear engagement operation; if the requirements are not met, the compensation torque adjustment continues until the conditions are 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 lower gear due to the larger transmission ratio, and correspondingly smaller in the higher gear. At the same time, it is corrected according to the oil temperature of the electric drive axle. The compensation torque needs to be appropriately increased at low and high temperatures, and 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 for lower gears and shorter for higher gears. At the same time, it is corrected according to the oil temperature. The torque compensation time is appropriately extended at low temperatures, slightly extended at high temperatures, and the reference value is maintained at normal temperatures.

[0098] In the above embodiments, by expanding the slip window and adjusting the compensation torque, the system's adaptability to long-term changing factors such as gear wear is improved. At the same time, the adjusted parameters are stored in non-volatile memory to ensure that these optimized parameters remain effective 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, steps S310 to S320 are also included.

[0100] Step S310: If synchronization is still not completed after performing the second preset number of re-gear shifting operations, generate target gear fault information.

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

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

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

[0104] Next, the slip window of the target gear is increased based on the number of times the gear engages and jams, and this expanded parameter is recorded in the NVRAM. These parameters will serve as an indicator of a fault in this gear position; finally, the target gear position is disabled, and it will not be used for shifting operations until the system is powered back on.

[0105] The above treatment can avoid wear and tear on the shifting system caused by repeated attempts, and at the same time provide a basis for subsequent fault diagnosis.

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

[0107] In one embodiment of the present invention, the speed adjustment module 410 is used to control the speed of the drive motor and the output shaft speed of the target dog tooth 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 configured to acquire the output shaft speed of the target dog tooth, determine the target speed range of the drive motor based on the output shaft speed, and finally adjust the speed of the drive motor to and maintain the target speed range. The target speed range is defined by both the output shaft speed and a 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. When the difference between the estimated displacement and the actual displacement exceeds a preset difference threshold, the shifting force of the shift motor is increased.

[0110] In one embodiment of the present invention, the estimation module 420 is further configured to detect the displacement data of the shift fork within a second preset time after entering the synchronization start point; determine the rate of change of the displacement data; determine the estimated shift fork displacement based on the rate of change and the preset synchronization time; 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 shifting 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, and then re-executes synchronization after the drive motor increases the feedforward torque.

[0112] In one embodiment of the invention, the synchronization module 430 is further configured to detect that the shift fork displacement has not reached the synchronization end point, and after the shift motor maintains the maximum synchronization force for a first preset time, perform a re-engagement operation. In the re-engagement operation, the shift motor is first controlled to drive the shift fork to move in the disengagement direction with the minimum disengagement force, and the displacement of the shift fork is detected. When the shift fork displacement is detected to reach the synchronization start point, the shift motor is controlled to maintain zero shift force. Then, a feedforward torque is superimposed on the speed regulation torque of the drive motor and maintained for a third preset time. After the third preset time ends, the shift motor is controlled to drive the shift fork to perform the synchronization operation with the maximum synchronization force.

[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 disengagement operation when the shift fork retracts to the synchronization start point and synchronization is not completed after a first preset number of times; then expand the range value of the preset slip window; when the dog tooth slip is detected to meet the expanded slip window, control the shift motor to perform a re-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 still not completed after performing a second preset number of re-gear shifting operations; and disable the target gear until the system is powered on again.

[0116] It should be noted that the embodiments of the device for improving the shift success rate of AMT and the method for improving the shift success rate of AMT provided in the above embodiments belong to the same concept. For details of their implementation process, please refer to the embodiments of the control method, which will not be repeated here.

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

[0118] This invention also provides an electronic device including a memory and a processor. The memory stores a computer program executed by the processor. When the computer program is executed by the processor, it causes the processor to perform the aforementioned method for improving the AMT shift success rate. The memory may also store various application programs and various data, such as various data used and / or generated by the application programs. The processor may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other processing units with data processing capabilities and / or instruction execution capabilities.

[0119] This invention also provides a computer-readable storage medium storing a computer program executed by a processor. When the computer program is executed by the processor, it causes the processor to perform the method for improving the AMT shift success rate as described above. Exemplarily, the computer storage medium may include a memory card of a smartphone, 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 disc 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 exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above exemplary embodiments are merely illustrative and are not intended to limit the scope of this application. Various changes and modifications can be made therein by those skilled in the art without departing from the scope and spirit of this application. All such changes and modifications are intended to be included within the scope of this application as claimed in the appended claims.

[0121] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of this application may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0122] Similarly, it should be understood that, in order to streamline this application and aid in understanding one or more of the various inventive aspects, features of this application may sometimes be grouped together in a single embodiment, figure, or description thereof in the description of exemplary embodiments of this application. However, this approach should not be construed as reflecting an intention that the claimed application requires more features than are expressly recited in each claim. Rather, as reflected in the corresponding claims, its inventive point lies in solving the corresponding technical problem with features fewer than all features of a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of this application.

[0123] Those skilled in the art will understand that, apart from the mutual exclusion of features, all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or elements of any method or apparatus so disclosed can be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature serving the same, equivalent, or similar purpose.

[0124] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A method for improving the success rate of gear shifting in an automatic transmission (AMT), characterized in that, include: Before engaging the target gear, the speed of the control drive motor and the output shaft speed of the target dog gear are kept within a preset slip window; The shift fork displacement is estimated based on the rate of change of displacement of the shift fork after the synchronization start point. When the difference between the estimated shift fork displacement and the actual shift fork displacement exceeds the preset difference threshold, the shifting 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, the shift motor is controlled to return the shift fork to the synchronization start point, and synchronization is re-executed after the drive motor increases the feedforward torque; Also includes: When the shift fork returns to the synchronization start point and synchronization is re-executed, and synchronization is still not completed after the first preset number of times, the shift motor is controlled to perform a disengagement operation. Expand the range of the preset slip window; When the dog tooth slip is detected to meet the expanded slip window, control the shift motor to re-execute the gear engagement operation; The step of re-performing synchronization after increasing the feedforward torque of the drive motor includes: superimposing the feedforward torque on the speed regulation torque of the drive motor and maintaining it for a third preset duration; after the third preset duration ends, controlling the shift motor to drive the shift fork to perform synchronization operation with the maximum synchronization force.

2. The method for improving the success rate of AMT gear shifting according to claim 1, characterized in that, The step of controlling the speed of the drive motor to remain within a preset slip window relative to the output shaft speed of the target dog tooth includes: Obtain the output shaft speed of the target dog tooth; The target speed range of the drive motor is determined based on the output shaft speed, wherein the target speed range is jointly limited by the output shaft speed and a preset slip window; Adjust the speed of the drive motor to the target speed range and maintain it.

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

4. The method for improving the success rate of AMT gear shifting according to claim 1, characterized in that, The step of controlling the shift motor to return the shift fork to the synchronization start point includes: The shift motor is controlled to drive the shift fork to move in the disengagement direction with minimal disengagement force. Detect the displacement of the shift fork; When the shift fork displacement is detected to reach the synchronization start point, the shift motor is controlled to maintain zero shifting force.

5. The method for improving the success rate of AMT gear shifting according to claim 1, characterized in that, Also includes: If synchronization is not completed after performing the second preset number of re-gear shifting operations, a target gear fault information is generated. Disable the target gear until the system is powered on again.

6. A device for improving the success rate of AMT gear shifting, characterized in that, include: The speed regulation module is used to control the speed of the drive motor and the output shaft speed of the target dog tooth to remain within a preset slip window before the target gear is engaged. The estimation module is used to estimate the shift fork displacement based on the displacement change rate of the shift fork after the synchronization start point. When the difference between the estimated shift fork displacement and the actual shift fork displacement exceeds the preset difference threshold, the shifting force of the shift motor is increased. 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, and then re-execute synchronization after the drive motor increases the feedforward torque; the synchronization module is also used to superimpose the feedforward torque on the speed regulation torque of the drive motor and maintain it for a third preset time. After the third preset time ends, the shift motor is controlled to drive the shift fork to perform the synchronization operation with the maximum synchronization force; The re-engagement module is used to re-execute synchronization when the shift fork returns to the synchronization start point. If synchronization is not completed after the first preset number of times, the module controls the shift motor to perform a disengagement operation to expand the range value of the preset slip window. When the dog tooth slip is detected to meet the expanded slip window, the module controls the shift motor to re-execute the engagement operation.

7. An electronic device, characterized in that, include: processor; as well as A memory configured to store computer-executable instructions, which, when executed, cause the processor to perform the method as described in any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores one or more programs that, when executed by an electronic device including multiple applications, cause the electronic device to perform the method as described in any one of claims 1 to 5.

9. A vehicle, characterized in that, Includes the device for improving the success rate of AMT shifting as described in claim 6.

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