Planet row structure gearbox gear shifting control method and system and vehicle

Abstract

The invention discloses a planet row structure gearbox gear shifting control method and system and a vehicle, and relates to the technical field of gearbox control, the method is applied to a planet row mechanical automatic gearbox without a synchronizer, and the method comprises the steps that gear and rotating speed information is obtained; calculating an initial target motor rotating speed corresponding to the target gear based on the planet row transmission relation; the initial target rotating speed is corrected according to the rotating speed change relation after gear shifting, upper correction is carried out during gear shifting, and lower correction is carried out during gear shifting; and the motor is controlled to adjust the speed according to the corrected rotating speed, and gear advancing is executed when the real-time rotating speed difference of related parts in the planet row falls into a preset gear advancing synchronization threshold value interval. The system comprises corresponding function modules. For a multi-axle drive vehicle, compensation is also performed based on other axle power disturbances. According to the invention, gear pushing and gear hitting during gear shifting can be effectively avoided, the gear shifting time is shortened, and the gear shifting smoothness and reliability are improved.

Description

Technical Field

[0001] This invention relates to the field of transmission control technology, and in particular to a method, system and vehicle for shift control of a planetary gearbox transmission. Background Technology

[0002] Automated Mechanical Transmission (AMT) is widely used in new energy commercial vehicles, especially heavy-duty trucks, due to its advantages of simple structure, low manufacturing cost, and high transmission efficiency. With the increasing demands for transmission system efficiency, lightweight design, and integration in the commercial vehicle market, AMT integrated electric drive axles using planetary gear sets as shift actuators are gaining attention. Planetary gear sets offer advantages such as high load-bearing capacity, smooth transmission, and compact structure, contributing to the miniaturization and efficiency of powertrain systems. To achieve faster shift response and higher shift efficiency, these transmissions typically eliminate traditional synchronizers, instead achieving gear shifting through precise and coordinated control of the rotational speeds of three key components in the planetary gear set: the sun gear, planet carrier, and ring gear.

[0003] However, the planetary gear set structure inherently possesses rotational speed coupling relationships. The rotational speeds of the sun gear, planet carrier, and ring gear are mutually constrained, making the speed regulation precision requirements during gear shifting extremely high. During gear shifting, if the relationship between the drive motor speed and the output shaft speed cannot be accurately coordinated to achieve ideal speed synchronization of the relevant components within the planetary gear set, phenomena such as "tooth knocking," shifting shock, or shifting failure are highly likely to occur. This not only affects shifting smoothness and driving experience but also causes impact damage to internal gears, coupling sleeves, and other components of the transmission, shortening the system's lifespan. Especially in multi-axle drive heavy-duty trucks (such as 6×4 models), the output shaft speed is easily disturbed during gear shifting due to the power coupling and load interaction between the drive axles, further increasing the difficulty of planetary gear set shifting synchronization control. Traditional control strategies based on calculating the target speed using a fixed speed ratio are often unsuitable for such complex operating conditions.

[0004] Therefore, there is an urgent need for a control method that can adapt to the structural characteristics of planetary gear sets, take into account the needs of different tooth profiles (such as pointed teeth and circular arc teeth), and achieve fast, smooth, and reliable gear shifting under various loads and drive axle configurations, so as to give full play to the technical advantages of planetary gear set AMT in commercial vehicle electric drive axles. Summary of the Invention

[0005] To address this, embodiments of the present invention provide a planetary gearbox shift control method, system, and vehicle to solve the problems of shift top teeth, impact, and long speed adjustment time caused by strong speed coupling within the planetary gearbox in the prior art.

[0006] To address the aforementioned technical problems, this invention provides a shift control method for a planetary gearbox, wherein the gearbox is a mechanical automatic gearbox with a planetary gearbox structure without a synchronizer. The method includes the following steps: Step S1: During the gear shifting process, acquire the current gear information, the target gear information, and the real-time speed information, including the output shaft speed, collected by the sensor; Step S2: Based on the planetary gear transmission relationship, calculate the initial target motor speed corresponding to the target gear. The planetary gear transmission relationship satisfies the formula: ,in, The rotational speed of the sun gear. The rotational speed of the gear ring is... For the planetary carrier rotation speed, These are the characteristic parameters of the planetary sorting system; Step S3: Based on the rotational speed change relationship of the planetary gear set components after disengagement, the initial target motor speed is corrected to generate the corrected target motor speed; the rotational speed change relationship satisfies: ,in, This represents the change in the rotational speed of the sun gear. This represents the change in the rotational speed of the gear ring. Step S4: Control the drive motor to adjust its speed according to the corrected target motor speed, and execute the gear shifting operation when the real-time speed difference of the relevant components inside the planetary gear set falls into the preset shifting synchronization threshold range.

[0007] Preferably, in step S3, the correction of the initial target motor speed includes: when performing an upshift operation, correcting the initial target motor speed upward; when performing a downshift operation, correcting the initial target motor speed downward.

[0008] Preferably, the preset shift synchronization threshold range is based on the allowable shift speed difference range between the ring gear and the planetary carrier of the planetary gear set. Certainly, among them ,and Less than the critical speed difference that may cause gear breakage .

[0009] Preferably, the shift synchronization threshold range is determined by the allowable shift speed difference range. This is obtained by mapping to the motor speed axis, specifically: ,in This is the transmission ratio from the motor to the sun gear.

[0010] Preferably, in step S3, the correction amount of the corrected target motor speed is based on the allowable gear shift speed difference range. The intermediate value is calculated as follows: .

[0011] Preferably, the method further includes setting an exit synchronization threshold range. When the real-time speed difference of the relevant components inside the planetary gear set exceeds the exit synchronization threshold range during the speed adjustment process, the current gear shift attempt is exited and speed adjustment is performed again.

[0012] Preferably, when the method is applied to a multi-axle drive vehicle, when the drive axle containing the transmission is shifting gears and other drive axles are in drive mode, the method is based on the planetary gear set speed relationship. It compensates for changes in output shaft speed caused by the influence of other axle power during gear shifting, among which, This represents the change in the planetary carrier rotation speed.

[0013] This invention also provides a planetary gearbox shift control system, which is used to implement the above-described planetary gearbox shift control method, specifically including: The data acquisition module is used to acquire gear information and real-time speed information, including the output shaft speed. The calculation module is used to calculate the initial target motor speed based on the planetary gear transmission relationship; The speed correction module is used to correct the initial target motor speed based on the speed change relationship of the planetary gear set components after disengaging. The motor control module is used to control the drive motor to run at the corrected target motor speed; The synchronization judgment and shift execution module is used to determine whether the real-time speed difference of relevant components inside the planetary gear set falls within the shift synchronization threshold range, and controls the shift execution mechanism to shift gears when the condition is met.

[0014] Preferably, the system further includes: Memory, used to store planetary sorting characteristic parameters Permissible gear shift speed difference range Critical risk speed difference and the transmission ratio from the motor to the sun gear ; The processor is configured to retrieve data from the memory and execute the functions of the calculation module and the speed correction module.

[0015] This invention also provides a vehicle including a planetary gearbox mechanical automatic transmission shift control system as described above.

[0016] As can be seen from the above technical solutions, this invention application has the following beneficial effects: (1) By introducing the relationship between the rotational speed changes after the planetary gear set is disengaged ( The target speed correction strategy for the motor is implemented, and a shift synchronization threshold range (such as) that matches the characteristics of the engagement gears is set. This allows for an active and controllable optimal meshing speed difference between key components inside the planetary gear set (such as the ring gear and planet carrier) during gear shifting, rather than pursuing absolute zero differential speed, thereby fundamentally avoiding tooth knocking, impact, and gear damage caused by improper speed difference.

[0017] (2) The strategy of “upward correction” and “downward correction” is adopted for upshifting and downshifting respectively. This directional correction utilizes the speed coupling characteristics of the planetary gear set, which can adjust the system to a speed difference state that is conducive to upshifting more quickly, optimize the dynamic response of the speed regulation stage, reduce the waiting time for absolute synchronization, and thus achieve fast and smooth gear switching.

[0018] (3) By establishing and applying the speed compensation relationship under multi-bridge dynamic coupling ( This system can compensate for the impact of disturbances on the output shaft speed when one drive axle shifts gears while other axles provide power. This allows the shift synchronization control strategy to adapt to load changes and power distribution between drive axles, ensuring the stability and reliability of the shifting process under different vehicle configurations and driving conditions. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Referring to the drawings will make the features and advantages of the present invention clearer. The drawings are illustrative and should not be construed as limiting the present invention in any way. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a flowchart of a planetary gearbox shift control method provided by the present invention; Figure 2 This is a simplified structural diagram of the planetary array in an embodiment of the present invention; Figure 3 This is a schematic diagram of the results of the conventional control method in the embodiments of the present invention; Figure 4 This is a schematic diagram showing the result of the control method of the present invention in an embodiment of the present invention; Figure 5 This is a block diagram of a planetary gearbox shift control system provided by the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1: To address the problems of gear shifting impact and long speed adjustment time caused by strong coupling of internal rotational speeds in the planetary gear set in the prior art, such as... Figure 1 As shown, this invention proposes a shift control method for a planetary gearbox, which is a synchronizerless planetary gearbox mechanical automatic transmission (AMT). The method includes the following steps: Step S1: During the gear shifting process, acquire the current gear information, the target gear information, and the real-time speed information, including the output shaft speed, collected by the sensor; Step S2: Based on the planetary gear transmission relationship, calculate the initial target motor speed corresponding to the target gear. The planetary gear transmission relationship satisfies the formula: ,in, The rotational speed of the sun gear. The rotational speed of the gear ring is... For the planetary carrier rotation speed, These are the characteristic parameters of the planetary sorting system; Step S3: Based on the speed change relationship of the planetary gear set components after disengagement, correct the initial target motor speed to generate the corrected target motor speed; the speed change relationship satisfies: ,in, This represents the change in the rotational speed of the sun gear. This represents the change in the rotational speed of the gear ring. Step S4: Control the drive motor to adjust its speed according to the corrected target motor speed, and execute the gear shifting operation when the real-time speed difference of the relevant components inside the planetary gear set falls into the preset shifting synchronization threshold range.

[0022] As can be seen from the above technical solution, this invention proposes a shift control method for a planetary gearbox structure gearbox. For a synchronizerless planetary gearbox AMT, it achieves fast, smooth, and reliable shifting through the following steps: Step S1, real-time acquisition of gear position and speed information to provide an accurate operating condition perception basis for control; Step S2, accurate calculation of the initial target motor speed based on the basic speed relationship of the planetary gearbox to establish the theoretical synchronization point; Step S3, innovatively utilizing the speed change relationship after disengaging the gear (… The initial target speed is directionally corrected (upshifting to correct, downshifting to correct), and a corrected target speed is generated in combination with the preset allowable gear shift speed difference range. This actively and quickly creates the optimal speed difference that is conducive to gear meshing, effectively avoiding the risk of tooth knocking and grinding. In step S4, the drive motor is quickly adjusted to the corrected speed, and the speed difference of the internal components of the planetary gear set is monitored in real time. Once it falls into the shift synchronization threshold range obtained by mapping the planetary gear set parameters and transmission ratio, the shift operation is immediately executed, ultimately achieving rapid synchronization and smooth engagement of the shifting process.

[0023] Further, in step S1, information acquisition is performed. During the gear shifting process, the current gear information, the target gear information, and real-time speed information, including the output shaft speed, collected by the sensor are acquired.

[0024] Specifically, the current gear and the target gear requested by the driver or vehicle controller are obtained through the transmission control unit (TCU). Simultaneously, the output shaft speed (i.e., planetary carrier speed) is acquired in real time via a speed sensor. (and can indirectly or directly obtain the rotational speed of the sun gear), Gear ring speed Wait for the signal.

[0025] Further, in step S2, the initial target motor speed is calculated. Based on the planetary gear transmission relationship, the initial target motor speed corresponding to the target gear is calculated.

[0026] Planetary gear transmissions follow the following basic relationship (Formula 1): , in, The rotational speed of the sun gear (unit: rpm); The gear ring speed (unit: rpm); The planetary carrier speed (unit: rpm) is equal to the output shaft speed. These are the planetary sorting characteristic parameters. Its value is generally greater than 1 and needs to be pre-calibrated according to the specific planetary gear structure (for example, if a certain model of planetary gear set has 60 teeth on the ring gear and 20 teeth on the sun gear, then...). The structure of a planetary array is as follows: Figure 2 As shown.

[0027] Based on the required gear ratio for the target gear, combined with the current output shaft speed. Formula 1 can be used to calculate the sun gear speed required to achieve theoretical synchronization of the planetary gear set. Then, based on the fixed transmission ratio from the motor to the sun gear... The initial target motor speed can then be calculated.

[0028] Further, in step S3, the target motor speed is corrected. Based on the speed change relationship of the planetary gear set components after disengagement, the initial target motor speed is corrected to generate the corrected target motor speed.

[0029] After disengaging from gear, the vehicle enters the neutral speed adjustment stage. At this time, the output shaft is connected to the wheels, and its speed (planetary carrier speed) is... The speed can be considered constant over a short period of time. Under this condition, differentiating Equation 1 yields the relationship between the speed change at the next moment after shifting gears (Equation 2): , in, This represents the change in the rotational speed of the sun gear. Let be the change in rotational speed of the ring gear. This formula shows that the change in rotational speed of the sun gear is inversely proportional to the change in rotational speed of the ring gear, and that for every change in rotational speed of the sun gear... A change of 1 rpm will cause a change in the speed difference between the gear ring and the planetary carrier.

[0030] Based on this physical relationship, and considering the actual meshing characteristics of the planetary gear set teeth (which can be pointed or curved), a reasonable speed difference, rather than an absolute zero difference, is required between the ring gear and the planet carrier (when upshifting) or between the ring gear and the housing (when downshifting) to achieve reliable and smooth gear engagement. This allowable engagement speed difference range is set as follows: ,in And the upper limit Less than the critical speed difference that may cause gear breakage .

[0031] Therefore, the initial target motor speed calculated in step S2 needs to be corrected in a directional manner: When performing a gear shift (the AMT gear ratio decreases, and the motor speed needs to decrease from high to low), the initial target motor speed is corrected upwards. According to Formula 2, the motor speed is corrected upwards (i.e., the sun gear speed is increased). This will reduce the rotational speed of the gear ring. This actively creates a negative speed difference between the gear ring and the planetary carrier that meets the requirements for gear shifting, which helps to accelerate synchronization and smoothly shift gears.

[0032] When performing a downshift (the AMT gear ratio increases, and the motor speed needs to increase from a low to a high), the initial target motor speed is corrected downwards. This downward correction of the motor speed (i.e., reducing the sun gear speed)... This will increase the rotational speed of the gear ring. This actively creates a positive speed difference between the gear ring and the planetary carrier that meets the requirements for gear shifting.

[0033] The specific value of the correction amount is based on the allowable gear shift speed difference range. The intermediate value is determined. Considering the transmission ratio mapping relationship, the correction amount for the corrected target motor speed is calculated as follows: , That is, the corrected target motor speed = the initial target motor speed ± the correction amount (upshifting is "+", downshifting is "-").

[0034] Simultaneously, by mapping the allowable shift speed difference range onto the motor speed shaft, the shift synchronization threshold range is obtained as follows: To ensure safety and prevent attempts to shift gears under unfavorable speed differences due to unexpected disturbances during speed adjustment, a wider range of exit synchronization thresholds has been set, for example... If the real-time speed difference exceeds this range, the current gear shift attempt will be terminated, and the speed will be readjusted.

[0035] Further, in step S4, speed adjustment and gear shifting are performed. The drive motor is controlled to adjust its speed according to the corrected target motor speed, and gear shifting is performed when the real-time speed difference of the relevant components inside the planetary gear set falls within the preset gear shifting synchronization threshold range.

[0036] The motor control module drives the motor to adjust to the corrected target speed. The synchronization judgment module continuously monitors and calculates the real-time speed difference between the ring gear and the planetary carrier (upshifting) or between the ring gear and the housing (downshifting). Once this speed difference enters the preset shift synchronization threshold range... When the optimal engagement conditions are considered to have been met, a shift command is immediately sent to the shift actuator to complete the shift.

[0037] Furthermore, compensation strategies for multi-axle drive vehicles (such as 6×4 models): In multi-axle drive vehicles, when the #1 axle transmission shifts gears while the #2 axle remains in drive mode, the output shaft speed of the #1 axle (planetary carrier speed) is... The value will change due to the dynamic disturbance of the #2 bridge and can no longer be considered constant.

[0038] During the torque control phase before gear shifting (e.g., the torque phase, where the input torque to the sun gear is controlled to be 0), the sun gear speed can be considered to be instantaneously constant. Substituting this condition into the variation relationship of Formula 1, we can derive the compensation relationship under multi-bridge interference (Formula 3): , in, This represents the change in the rotational speed of the disturbed planetary carrier.

[0039] Based on Formula 3, the output shaft speed change caused by the dynamic coupling of other drive axles can be estimated in real time. This allows us to deduce its rotational speed relative to the gear ring. And the influence of gear shift speed difference. The control system can use this to dynamically compensate for the target motor speed or synchronization threshold, thus maintaining fast and reliable gear shift synchronization control even under complex multi-axle power coupling conditions. For example, when an unloaded vehicle shifts up, if the #2 axle drive causes the #1 axle to accelerate ( According to Formula 3, the gear ring speed will also change in the same direction, but the magnitude will be smaller. The gear shift speed difference does not change much, and the system is easy to maintain within the synchronization threshold; if deceleration occurs, this logic can also be used to analyze and maintain control robustness.

[0040] The technical effects of this invention were verified through comparative experiments. The test subject was the same 4×2 new energy heavy truck, using both a traditional control method (based on a fixed speed ratio to calculate the target speed without a correction strategy) and the control method of this invention. The experimental results show that the control method of this invention fundamentally solves the problems of gear engagement and shifting difficulties after synchronization in the traditional method, avoiding gear grinding; by precisely controlling the motor speed, the average shifting time is shortened, improving shifting efficiency; shifting impact is significantly reduced, component wear is greatly reduced, and the service life of the gearbox is extended. Figure 3 (In the traditional gear shifting process, there are top teeth) and Figure 4 (The shifting process in this invention is characterized by smooth and synchronized rotational speed.)

[0041] Example 2: Figure 5 As shown, the present invention provides a planetary gearbox shift control system. This system is used to implement the planetary gearbox shift control method of Embodiment 1 above, specifically including: Data acquisition module: used to acquire current gear information, target gear information, and real-time speed information, including output shaft speed, collected by sensors.

[0042] Calculation module: used to calculate the initial target motor speed based on the planetary gear transmission relationship (Formula 1).

[0043] Speed ​​correction module: It is used to correct the initial target motor speed based on the speed change relationship after disengaging the gear (Formula 2) and the direction of upshifting / downshifting, generate the corrected target motor speed, and determine the gear shifting synchronization threshold range and the exit synchronization threshold range.

[0044] Motor control module: Used to control the drive motor to run at the corrected target motor speed, thereby achieving rapid speed adjustment.

[0045] Synchronization Judgment and Shift Execution Module: This module is used to calculate and determine in real time whether the real-time speed difference of relevant components inside the planetary gear set (such as the gear ring and planetary carrier) falls within the shift synchronization threshold range, and when the condition is met, it controls the shift execution mechanism (such as the shift motor or cylinder) to perform the shift operation; at the same time, it monitors whether the speed difference exceeds the exit synchronization threshold range to determine whether to stop the shift attempt.

[0046] Furthermore, the system also includes: Memory, used to store planetary sorting characteristic parameters Permissible gear shift speed difference range Critical risk speed difference and the transmission ratio from the motor to the sun gear ; The processor (such as the microcontroller in the TCU) is configured to call data in memory and execute the core algorithm functions of the calculation module, speed correction module, synchronization judgment and shift execution module, and coordinate the work of each module.

[0047] Through the coordinated operation of the above modules, the system achieves precise, rapid, and reliable control of the shifting process of a synchronizerless planetary gearbox AMT.

[0048] This embodiment provides a planetary gearbox shift control system for implementing the aforementioned planetary gearbox shift control method. Therefore, the specific implementation of the planetary gearbox shift control system can be found in the previous section on the embodiments of the planetary gearbox shift control method. To avoid redundancy, it will not be repeated here.

[0049] Example 3: This embodiment of the invention provides a vehicle equipped with a planetary gearbox mechanical automatic transmission shift control system as described in Example 2. This vehicle is preferably a commercial vehicle, particularly a new energy heavy-duty truck, including but not limited to multi-axle drive configurations such as 4×2 and 6×4. This system can effectively manage the shifting process of the planetary gearbox, improving shift smoothness, shortening shift time, and reducing impact and wear, thereby improving the overall vehicle's power, economy, and reliability.

[0050] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0051] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0052] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The functions specified in one or more boxes. These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable apparatus for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0053] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A shift control method for a planetary gearbox, wherein the gearbox is a synchronizerless planetary gearbox mechanical automatic gearbox, characterized in that... Includes the following steps: Step S1: During the gear shifting process, acquire the current gear information, the target gear information, and the real-time speed information, including the output shaft speed, collected by the sensor; Step S2: Based on the planetary gear transmission relationship, calculate the initial target motor speed corresponding to the target gear. The planetary gear transmission relationship satisfies the formula: ,in, The rotational speed of the sun gear. The rotational speed of the gear ring is... For the planetary carrier rotation speed, These are the characteristic parameters of the planetary sorting system; Step S3: Based on the rotational speed change relationship of the planetary gear set components after disengagement, the initial target motor speed is corrected to generate the corrected target motor speed; the rotational speed change relationship satisfies: ,in, This represents the change in the rotational speed of the sun gear. This represents the change in the rotational speed of the gear ring. Step S4: Control the drive motor to adjust its speed according to the corrected target motor speed, and execute the gear shifting operation when the real-time speed difference of the relevant components inside the planetary gear set falls into the preset shifting synchronization threshold range.

2. The planetary gearbox shift control method according to claim 1, characterized in that, In step S3, the correction of the initial target motor speed includes: when performing an upshift operation, correcting the initial target motor speed upward; when performing a downshift operation, correcting the initial target motor speed downward.

3. The shift control method for a planetary gearbox according to claim 1 or 2, characterized in that, The preset shift synchronization threshold range is based on the allowable shift speed difference range between the ring gear and the planetary carrier of the planetary gear set. Certainly, among them ,and Less than the critical speed difference that may cause gear breakage .

4. The planetary gearbox shift control method according to claim 3, characterized in that, The shift synchronization threshold range is determined by the allowable shift speed difference range. This is obtained by mapping to the motor speed axis, specifically: ,in This is the transmission ratio from the motor to the sun gear.

5. The planetary gearbox shift control method according to claim 4, characterized in that, In step S3, the correction amount of the target motor speed is based on the allowable gear shift speed difference range. The intermediate value is calculated as follows: .

6. The shift control method for a planetary gearbox according to claim 1, characterized in that, The method also includes setting an exit synchronization threshold range. When the real-time speed difference of the relevant components inside the planetary gear set exceeds the exit synchronization threshold range during the speed adjustment process, the current gear shift attempt is exited and the speed adjustment is restarted.

7. The planetary gearbox shift control method according to claim 1, characterized in that, When the method is applied to a multi-axle drive vehicle, it is used when the drive axle containing the transmission is shifting gears and other drive axles are in drive mode, based on the planetary gear set speed relationship. It compensates for changes in output shaft speed caused by the influence of other axle power during gear shifting, among which, This represents the change in the planetary carrier rotation speed.

8. A planetary gearbox shift control system, characterized in that, The system is used to implement the planetary gearbox shift control method according to any one of claims 1 to 7, specifically including: The data acquisition module is used to acquire gear information and real-time speed information, including the output shaft speed. The calculation module is used to calculate the initial target motor speed based on the planetary gear transmission relationship; The speed correction module is used to correct the initial target motor speed based on the speed change relationship of the planetary gear set components after disengaging. The motor control module is used to control the drive motor to run at the corrected target motor speed; The synchronization judgment and shift execution module is used to determine whether the real-time speed difference of relevant components inside the planetary gear set falls within the shift synchronization threshold range, and controls the shift execution mechanism to shift gears when the condition is met.

9. The planetary gearbox shift control system according to claim 1, characterized in that, The system also includes: Memory, used to store planetary sorting characteristic parameters Permissible gear shift speed difference range Critical risk speed difference and the transmission ratio from the motor to the sun gear ; The processor is configured to retrieve data from the memory and execute the functions of the calculation module and the speed correction module.

10. A vehicle, characterized in that, Including the planetary gearbox structure mechanical automatic transmission shift control system as described in claim 8 or 9.

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