Gear shifting method, device and vehicle

Abstract

Embodiments of the present application provide a shifting method, apparatus, and vehicle. The method, applied to an automated manual transmission (AMT) transmission controller, comprises: obtaining the current temperature of a motor; obtaining a shifting pattern corresponding to the current temperature based on a preset motor temperature threshold; obtaining a corresponding shifting curve based on the shifting pattern; and executing a shifting operation based on the shifting curve to control the power system to achieve the corresponding power output. The embodiments of the present application provide different shifting curves for the AMT transmission based on different motor temperature scenarios to balance the relationship between power output and motor temperature, preventing sudden drops in motor power or automatic shutdown protection due to excessive motor temperature, and improving vehicle operating safety.

Description

Technical Field

[0001] The embodiments of the present application relate to the automotive field, and in particular to a gear shifting method, device, and vehicle. Background Art

[0002] Currently, more and more new energy electric vehicles are beginning to adopt permanent magnet synchronous motor + AMT (Automated Manual Transmission) solutions, giving the electric drive system multiple advantages in cost, weight, efficiency, etc.

[0003] The current AMT shifting strategy mainly considers the power, economy and drivability of the vehicle. The shifting curve for each gear is set according to the vehicle's maximum climbing grade, acceleration performance and throttle opening. The high-efficiency zone of the electric drive system (including the motor, motor controller and transmission mechanism) and the smoothness of the vehicle's driving are then considered for optimization to formulate the final shifting curve.

[0004] Under extreme operating conditions, such as frequent acceleration and deceleration and vehicle overload, motor temperatures can rise rapidly. Permanent magnet synchronous motors, which use permanent magnets to create an excitation magnetic field, are subject to demagnetization risk at high temperatures. When the motor temperature is too high, the motor controller will reduce power or even shut down the motor for protection. Sudden motor power reduction or shutdown can cause a sudden loss of power and vehicle roll, impacting not only vehicle performance but also posing a safety hazard. Summary of the Invention

[0005] Embodiments of the present application provide a shifting method, device, and vehicle to solve the problems of sudden power interruption and vehicle rolling downhill caused by overheating of the vehicle motor.

[0006] In order to solve the above problems, the first aspect of an embodiment of the present application discloses a shifting method, which is applied to an AMT transmission controller and specifically includes: obtaining the current temperature of the motor; obtaining a shifting mode corresponding to the current temperature based on a preset motor temperature threshold; obtaining a corresponding shifting curve based on the shifting mode; performing a shifting operation based on the shifting curve, and controlling the power system to complete the corresponding power output.

[0007] Optionally, according to a preset motor temperature threshold, a shifting mode corresponding to the current temperature is obtained, including: when the current temperature does not exceed the first motor temperature threshold T1, obtaining a first shifting mode; when the current temperature exceeds the first motor temperature threshold T1 and does not exceed the second motor temperature threshold T2, obtaining a second shifting mode; when the current temperature exceeds the second motor temperature threshold T2 and does not exceed the third motor temperature threshold T3, obtaining a third shifting mode; when the current temperature exceeds the third motor temperature threshold T3, obtaining a fourth shifting mode.

[0008] Optionally, according to the shifting mode, a corresponding shifting curve is obtained, including: according to the first shifting mode, obtaining a first shifting curve; according to the second shifting mode, obtaining a second shifting curve; according to the third shifting mode, obtaining a third shifting curve; according to the fourth shifting mode, obtaining a fourth shifting curve; wherein, from the first shifting curve to the fourth shifting curve, any level of shifting curve realizes at least one of the following control functions compared with the previous level of shifting curve: reducing the shifting frequency, reducing the motor power, reducing the vehicle's driving acceleration, and reducing the vehicle's driving speed upper limit.

[0009] Optionally, it also includes: pre-setting a first gear shift curve, including: pre-setting a first gear shift curve according to the optimal principle of vehicle power and economy, the first gear shift curve is used to control the motor to maintain the power, economy and drivability of the vehicle; pre-setting a second gear shift curve according to the optimization principle of motor heat generation, the second gear shift curve enables the motor to operate in a working area with low loss to reduce the heat generated by the motor; pre-setting a third gear shift curve according to the principle of maintaining the minimum power of the vehicle, the third gear shift curve is used to limit the motor output and limit the driving torque to maintain the minimum power of the vehicle; pre-setting a fourth gear shift curve according to the motor demagnetization protection principle, the fourth gear shift curve is used to control the motor shutdown protection.

[0010] Optionally, according to the shifting mode, a corresponding shifting curve is obtained, including: according to the shifting mode, a corresponding initial shifting curve is obtained; based on the power output principle of the current shifting mode, a corresponding curve correction factor is obtained; according to the curve correction factor, the initial shifting curve is corrected to obtain a corresponding shifting curve; the curve correction factor includes at least any one of the following: a motor efficiency map, the current speed of the vehicle, the current acceleration of the vehicle, and the minimum driving torque required by the vehicle.

[0011] Optionally, based on the power output principle of the current shift mode, a corresponding curve correction factor is obtained, and the initial shift curve is corrected according to the curve correction factor to obtain a corresponding shift curve, including: according to the optimization principle of motor heat generation, a motor efficiency map is obtained, and according to the motor efficiency map, the initial shift curve is corrected to obtain the shift curve.

[0012] Optionally, based on the power output principle of the current shifting mode, a corresponding curve correction factor is obtained, and the initial shifting curve is corrected according to the curve correction factor to obtain a corresponding shifting curve, including: according to the principle of maintaining the minimum power of the whole vehicle, the current speed of the whole vehicle, the current acceleration of the whole vehicle, and the minimum driving torque required by the whole vehicle are obtained, and according to the current speed of the whole vehicle, the current acceleration of the whole vehicle, and the minimum driving torque required by the whole vehicle, the initial shifting curve is corrected to obtain the shifting curve.

[0013] Optionally, the motor speed upper limit n is calculated based on the vehicle's driving speed upper limit and the vehicle's maximum driving acceleration set by the initial shift curve; the minimum driving torque T required for the vehicle is calculated based on the current speed and current acceleration of the vehicle, as well as the minimum power requirement for the vehicle to maintain operation; based on the formula T=9550*P / n, combined with the motor efficiency and vehicle power loss parameters, the minimum motor power is set to maintain the minimum operating power of the vehicle; and the shift curve is formulated based on the minimum motor power.

[0014] A second aspect of an embodiment of the present application discloses a shifting device, which is applied to an AMT transmission controller and includes:

[0015] Temperature acquisition module, to obtain the current temperature of the motor;

[0016] A mode acquisition module, which acquires a shift mode corresponding to the current temperature according to a preset motor temperature threshold;

[0017] A curve acquisition module, which acquires a corresponding shift curve according to the shift mode;

[0018] The output control module performs a shift operation based on the shift curve and controls the power system to achieve corresponding power output.

[0019] Optionally, the mode acquisition module includes:

[0020] a first shift mode acquisition module, configured to acquire a first shift mode when the current temperature does not exceed a first motor temperature threshold T1;

[0021] a second shift mode acquisition module, configured to acquire a second shift mode when the current temperature exceeds a first motor temperature threshold T1 and does not exceed a second motor temperature threshold T2;

[0022] a third shift mode acquisition module, configured to acquire a third shift mode when the current temperature exceeds the second motor temperature threshold T2 and does not exceed the third motor temperature threshold T3;

[0023] The fourth shift mode acquisition module is configured to acquire the fourth shift mode when the current temperature exceeds a third motor temperature threshold T3.

[0024] Optionally, the curve acquisition module includes:

[0025] a first shift curve acquiring module, configured to acquire a first shift curve according to the first shift pattern;

[0026] a second shift curve acquiring module, configured to acquire a second shift curve according to the second shift pattern;

[0027] a third shift curve acquiring module, configured to acquire a third shift curve according to the third shift mode;

[0028] a fourth shift curve acquiring module, configured to acquire a fourth shift curve according to the fourth shift mode;

[0029] Among them, from the first shift curve to the fourth shift curve, any shift curve achieves at least one of the following control functions compared with the previous shift curve: reducing the shift frequency, reducing the motor power, reducing the vehicle's driving acceleration, and reducing the vehicle's driving speed upper limit.

[0030] Optionally, the curve acquisition module further includes:

[0031] An initial shift curve acquisition module, configured to acquire a corresponding initial shift curve according to the shift mode;

[0032] A curve correction factor acquisition module is used to obtain a corresponding curve correction factor based on the power output principle of the current shift mode;

[0033] a curve correction module, configured to correct the initial shift curve according to the curve correction factor to obtain a corresponding shift curve;

[0034] The curve correction factor includes at least any one of the following: a motor efficiency map, a current speed of the vehicle, a current acceleration of the vehicle, and a minimum driving torque required by the vehicle.

[0035] Optionally, the curve correction module includes:

[0036] The second curve correction module is used to obtain a motor efficiency map according to the optimization principle of motor heat amount, and correct the initial shift curve according to the motor efficiency map to obtain the shift curve.

[0037] The third curve correction module is used to obtain the current speed of the vehicle, the current acceleration of the vehicle, and the minimum driving torque required by the vehicle based on the principle of maintaining the minimum power of the vehicle, and correct the initial shift curve according to the current speed of the vehicle, the current acceleration of the vehicle, and the minimum driving torque required by the vehicle to obtain the shift curve.

[0038] The third curve correction module further includes:

[0039] The motor speed upper limit n is calculated based on the vehicle's driving speed upper limit and the vehicle's maximum driving acceleration set by the initial shift curve; the minimum driving torque T required for the vehicle is calculated based on the current speed and current acceleration of the vehicle, as well as the minimum power requirement for the vehicle to maintain operation; based on the formula T=9550*P / n, combined with the motor efficiency and the vehicle's power loss parameters, the minimum motor power is set to maintain the minimum operating power of the vehicle; and the shift curve is formulated based on the minimum motor power.

[0040] The second curve correction module is used to obtain a motor efficiency map according to the optimization principle of motor heat amount, and correct the initial shift curve according to the motor efficiency map to obtain the shift curve.

[0041] Optionally, the device further includes a shift curve preset module, and the shift curve preset module includes:

[0042] A first shift curve presetting module is used to pre-set a first shift curve, including: pre-setting the first shift curve according to an optimal principle of vehicle power and economy, wherein the first shift curve is used to control the motor to maintain vehicle power, economy, and drivability;

[0043] a second shift curve presetting module, configured to pre-set a second shift curve based on a principle of optimizing heat generation of the motor, wherein the second shift curve causes the motor to operate in a low-loss operating area to reduce heat generation of the motor;

[0044] A third shift curve preset module is used to preset a third shift curve based on the principle of maintaining the minimum power of the entire vehicle. The third shift curve is used to limit the output of the motor and the driving torque to maintain the minimum power of the entire vehicle;

[0045] The fourth shift curve preset module is used to preset a fourth shift curve according to the motor demagnetization protection principle, and the fourth shift curve is used to control the motor shutdown protection.

[0046] A third aspect of an embodiment of the present application discloses a vehicle, which includes an AMT transmission controller, and the AMT transmission controller implements the steps of the method described in the first aspect of the present application.

[0047] The embodiments of the present application offer the following advantages: differentiated shift control based on motor temperature, providing different shift curves at different motor temperatures. The shift curve imposes stricter limits on power output at higher temperatures, preventing motor overheating and thus avoiding sudden power interruptions and vehicle slippage caused by overheating. Furthermore, the embodiments of the present application can directly use a preset initial shift curve as the shift curve, or use shift curves derived from different shift modes, according to different power output principles, and based on different curve correction factors. This can further balance the relationship between vehicle power output and temperature, thereby achieving a better balance between vehicle power performance and safety performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0049] Figure 1 This is a flow chart of a shifting method proposed in an embodiment of the present application;

[0050] Figure 2 It is a motor efficiency map;

[0051] Figure 3 This is a flow chart of a method for formulating a shift strategy based on motor temperature provided in an embodiment of the present application;

[0052] Figure 4 This is a structural block diagram of a shifting device proposed in an embodiment of the present application. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0054] Currently, new energy electric vehicles that use a permanent magnet synchronous motor and AMT (Automated Mechanical Transmission) solution offer multiple advantages in terms of cost, weight, and efficiency in their electric drive systems. The AMT transmission is an improvement on the traditional manual gear transmission, combining the advantages of automatic shifting with the high efficiency, low cost, simple structure, and ease of manufacturing of the original manual transmission gear drive.

[0055] First, the shifting principle of an electric vehicle with an automatic transmission (AMT) is described. During driving, the VCU (Vehicle Control Unit) automatically simulates the driver's actions. Coordinated control signals from the VCU are transmitted via the CAN bus. The TCU (Transmission Control Unit) controls the AMT transmission's shifting to adjust torque and speed. The MCU (Motor Control Unit) controls the motor's output power, replacing manual operation with mechanical actuation to achieve gear control. During driving, the driver transmits control signals to the vehicle's power control system via the accelerator pedal. The vehicle's power control system collects signals from sensors such as the motor speed sensor, vehicle speed sensor, acceleration sensor, and power supply sensor to monitor the vehicle's driving status in real time. Based on these signals, the system, according to a pre-stored control program, comprehensively considers the optimal shifting schedule and motor power supply adaptive regulation, achieving optimal matching of the motor and transmission's actions and operating sequences. This results in excellent vehicle dynamics, energy efficiency, smooth starting, and rapid shifting, meeting the driver's expectations.

[0056] Specifically, the specific process of shifting an AMT electric vehicle is as follows: (1) the transmission controller TCU receives the shift instruction issued by the vehicle controller VCU. After receiving the control right, the transmission controller TCU starts to execute the shift control. The motor controller MCU controls the output torque target of the drive motor to be reduced to zero, controls the motor to enter the free mode, moves the shift fork to complete the gear shifting, ends the torque phase, and enters the inertia phase. (2) The motor controller MCU controls the drive motor to be adjusted to the torque mode, and adjusts the drive motor speed to the desired target speed. (3) The motor controller MCU controls the drive motor to be adjusted to the free mode, reduces the output torque of the drive motor to zero, controls the motor to enter the free mode, moves the shift fork to complete the gear shifting, and ends the inertia phase. (4) The drive motor torque is restored to the value before the shift, and the vehicle control right is returned to the vehicle controller VCU, and the shift process ends. Among them, the shift instruction may include a shift curve.

[0057] Specifically, the specific process of another AMT electric vehicle shifting is as follows: (1) According to the shifting rule, after reaching the shifting point, the AMT speed controller sends a torque gradient control mode request to the drive motor controller. When the motor drive torque gradually decreases, the motor driver controls the motor to be in free mode and feeds back the status to the AMT speed controller. (2) After receiving the status feedback that the motor is in free mode, the AMT speed controller controls the transmission to complete the gear shifting action. (3) After the transmission is in neutral, the AMT speed controller sends a speed regulation mode request to the motor controller. The motor controller adjusts the speed according to the target speed sent by the AMT speed controller. The target speed is calculated by the AMT speed controller based on the vehicle speed and the target gear. (4) While the motor is regulating the speed, the AMT speed controller controls the transmission to complete the gear selection operation. (5) After the target speed is reached, the AMT speed controller sends a motor free mode request to the motor controller. (6) After confirming that the motor is in free mode, the AMT speed controller performs the gear shifting operation. (7) After completing the gear shift operation, the AMT transmission controller sends a torque mode request to the control motor, and the motor returns to the normal torque output mode and enters the normal driving state.

[0058] The above two types of AMT electric vehicles essentially control gear shifting through the AMT transmission controller to complete the vehicle's power output. Referring to the above description, the current shifting strategy of the electric vehicle AMT transmission controller is based on a preset control program, taking into account the power and economy of the entire vehicle, setting the shift curve for each gear, and then considering the low-loss and high-efficiency working area of the motor drive system, driving comfort requirements, etc., to optimize the set shift curve to formulate the final shift curve.

[0059] At present, the most widely used motor in pure electric vehicles is the permanent magnet synchronous motor. The permanent magnet synchronous motor uses permanent magnets to provide excitation, which makes the motor structure simpler, reduces processing and assembly costs, and eliminates the slip rings and brushes that are prone to problems, thereby improving the reliability of the motor operation. Because no excitation current is required and there is no excitation loss, the efficiency and power density of the motor are improved.

[0060] However, because permanent magnet synchronous motors (PMSMs) use permanent magnets to create an excitation magnetic field, they are at risk of demagnetization at high temperatures. When the motor temperature is too high, the motor controller will control the motor to reduce power or even shut down for protection. A sudden power reduction or power interruption can affect vehicle dynamics and driving safety. Existing shifting strategies only ensure the normal operation of the vehicle's drive system when the electric drive system is operating normally, but fail to account for extreme operating conditions such as frequent acceleration and deceleration and vehicle overload. If the motor is overloaded or operating at excessively high loads, continuing with the normal shifting strategy can lead to sudden power interruption and vehicle roll due to excessive motor temperature. For example, if an electric vehicle's motor has been operating on a steep slope for an extended period of time, it is very likely to overheat. If the motor automatically shuts down for protection, the sudden power interruption could cause the vehicle to roll down the slope, posing a safety hazard.

[0061] Based on the existing relevant technologies, this application takes the motor temperature into consideration in the shifting strategy to prevent the motor power from dropping suddenly or causing sudden shutdown protection due to excessive motor temperature, so that the power and safety of the entire vehicle can be protected under some extreme and overload conditions, thereby improving the safety of vehicle operation.

[0062] Figure 1 This is a flow chart of a shifting method proposed in an embodiment of the present application. Figure 1 As shown, the method is applied to an AMT transmission controller of an electric vehicle, comprising the following steps:

[0063] Step S11: Acquire the current temperature of the motor.

[0064] The AMT transmission controller monitors the temperature signal from the motor temperature sensor in real time and uses the temperature value returned by the motor temperature sensor as the current motor temperature. If there are multiple motor temperature sensors and they return multiple temperature values at a given moment, the maximum of these multiple temperature values is used as the current motor temperature.

[0065] In this embodiment, the temperature data packet transmission frequency can be set based on the characteristics of different motor temperature sensing systems, and the temperature data packets are periodically transmitted to the vehicle control unit (VCU) via the CAN bus. The VCU can use this temperature data to plot a real-time motor temperature curve and display it on the vehicle display, allowing the user to intuitively understand the current motor temperature value and its changes, thereby providing auxiliary guidance for subsequent vehicle operations.

[0066] The real-time monitoring temperature of the motor is obtained. On the one hand, it is used as an input variable for the shifting strategy, and on the other hand, it is also used to strengthen the real-time monitoring of the motor temperature data. Current automobile motors are equipped with temperature sensors, which are used to control the motor controller to reduce power or automatically shut down for protection when the motor is detected to be overheated. The embodiment of the present application can be based on existing automobile motors without modifying or adding hardware. The current temperature of the motor can be obtained through the AMT speed controller or the vehicle controller (the vehicle controller can transmit data and instructions to the speed controller via the CAN bus).

[0067] Step S12: acquiring a shift mode corresponding to the current temperature according to a preset motor temperature threshold.

[0068] Before step S12, the method further includes: step S120, presetting the motor temperature threshold. Step S120 includes:

[0069] S120-1, motor temperature setting basis:

[0070] The method includes setting multiple motor temperature thresholds based on the heat resistance characteristics of the motor. Specifically, the motor's thermal property-related parameters can be obtained according to different power vehicle models and different motor models to set multiple motor temperature thresholds.

[0071] For example, the number of the motor temperature thresholds may be three, corresponding to a first motor temperature threshold T1, a second motor temperature threshold T2, and a third motor temperature threshold T3, wherein T1<T2<T3. The third motor temperature threshold T3 is the highest temperature threshold of the motor.

[0072] S120-2, setting basis of the third motor temperature threshold T3:

[0073] Assuming that the temperature threshold for the motor automatic shutdown protection is Ts, this embodiment can set the highest temperature threshold of the motor, ie, the third motor temperature threshold T3, according to the temperature threshold Ts.

[0074] In one embodiment provided herein, the third motor temperature threshold T3 is set to be less than the temperature threshold Ts for the motor automatic shutdown protection, thereby providing more flexible operating time before the motor controller controls the motor to automatically shut down for protection. The specific value of Ts can be obtained from the motor's instruction manual or operating instructions, or through experimental testing.

[0075] Exemplarily, T3 can be set to Ts-5° C. Assuming that the value of Ts is 165° C., T3 is set to 160° C. in this embodiment.

[0076] S120-3, Temperature ranges and corresponding explanations:

[0077] In this embodiment, the motor temperature threshold divides the motor temperature into multiple temperature intervals, and different temperature intervals correspond to different shift modes. Specifically, corresponding to the above example, the multiple temperature intervals specifically include:

[0078] The first temperature interval [-∞, T1];

[0079] The second temperature interval [T1, T2];

[0080] The third temperature interval [T2, T3];

[0081] The fourth temperature interval (T3, +∞].

[0082] In the first temperature range [-∞, T1], it means that the motor is in the normal operating temperature range.

[0083] In the second temperature range (T1, T2), the motor is in a low-risk overtemperature range. At this time, the motor temperature is high and has exceeded the temperature range for normal operation of the motor, but the risk of motor power drop or shutdown protection is low.

[0084] In the third temperature range (T2, T3), the motor is in a high-risk overtemperature range. At this time, the motor temperature is too high and close to the temperature threshold for shutdown protection. The risk of power drop or shutdown protection is high.

[0085] In the fourth temperature range (T3, +∞], the motor temperature enters the temperature range that requires active shutdown protection. For the sake of motor demagnetization protection, the motor can be actively controlled to perform shutdown protection to avoid automatic power drop or automatic shutdown protection of the motor.

[0086] For example, the first motor temperature threshold T1 is set to 135°C, the second motor temperature threshold T2 is set to 145°C, and the third motor temperature threshold T3 is set to 160°C. Accordingly, the multiple temperature intervals may be [-∞, 135°C], (135°C, 145°C], (145°C, 160°C], (160°C, +∞].

[0087] The step S12 further includes a method S121 for obtaining a shift mode according to a temperature threshold. The step S121 includes:

[0088] S121-1, obtaining a shift mode according to the temperature threshold preset in step S120:

[0089] In one embodiment of the present application, obtaining a shift mode corresponding to the current temperature according to a preset motor temperature threshold includes:

[0090] When the current temperature does not exceed the first motor temperature threshold T1, obtaining a first shift mode;

[0091] When the current temperature exceeds a first motor temperature threshold T1 and does not exceed a second motor temperature threshold T2, acquiring a second shift mode;

[0092] When the current temperature exceeds the second motor temperature threshold T2 and does not exceed the third motor temperature threshold T3, acquiring a third shift mode;

[0093] When the current temperature exceeds the third motor temperature threshold T3, a fourth shift mode is acquired.

[0094] S121-2, Correspondence between shifting mode and power output principle:

[0095] In the embodiments of the present application, different shift modes correspond to different shift curves and may also correspond to different power output principles. Based on the power output principles, the shift curves are adjusted to control the power system to achieve a power output that is appropriate for the current temperature of the motor. Based on the power output principles, the transmission controller can consider different parameter variables to execute shift operations.

[0096] The power output principle includes the principle of optimizing the power and economy of the vehicle, the principle of optimizing the heat output of the motor, the principle of maintaining the minimum power of the vehicle, and the principle of motor demagnetization protection.

[0097] Specifically, when the current temperature does not exceed the first motor temperature threshold T1, it indicates that the vehicle motor is in a normal operating temperature range and there is no need to worry about the risk of increased motor temperature. At this time, the first shift mode is acquired to use the normal shift control strategy of the vehicle. The control shift strategy at this time mainly considers basic performance of the vehicle, such as power, comfort, and drivability, and can meet the optimal principle of vehicle power and economy.

[0098] When the current temperature exceeds the first motor temperature threshold T1 and does not exceed the second motor temperature threshold T2, the motor temperature is higher than the normal operating state of the motor, but is still in a low-risk overtemperature state, and the risk of motor power drop or shutdown protection is low; at this time, the second shift mode is obtained, and the motor output is optimized based on the consideration of the vehicle's power, comfort and drivability, such as reducing the shift frequency, making the motor work in the high-efficiency working area as much as possible, etc., to reduce the heat generated by the motor, corresponding to the optimization principle of motor heat generation.

[0099] When the current temperature exceeds the second motor temperature threshold T2 and does not exceed the third motor temperature threshold T3, the motor temperature is already in a high-risk overtemperature state, and the risk of the motor automatically reducing power and shutting down for protection is already high, but the motor does not need to be shut down immediately for protection. At this time, the third shift mode is obtained to limit the power output of the motor, reduce the acceleration or maximum speed of the vehicle, and make the AMT work in a low gear. As long as the climbing ability of the vehicle can be guaranteed, the heat generated by the motor can be further reduced, the temperature of the motor can be lowered, and the motor can be prevented from suddenly dropping power or suddenly shutting down for protection, thereby improving driving safety. At this time, the principle of maintaining the minimum power of the vehicle can be maintained.

[0100] When the current temperature exceeds the third motor temperature threshold T3, the fourth shift mode is acquired. At this time, the motor is actively controlled by the motor controller to perform shutdown protection, which corresponds to the motor demagnetization protection principle.

[0101] The step S12 further includes a method S122 for providing a vehicle warning according to the current temperature of the motor:

[0102] In an embodiment of the present application, when the current temperature of the motor is detected to be approaching or exceeding a preset motor temperature threshold, a vehicle warning can be provided to the user in any one or more forms of voice, text, or graphical display, reminding the user whether to take appropriate actions to ensure driving safety. Specifically, when the current temperature exceeds the second motor temperature threshold T2 but does not exceed the third motor temperature threshold T3, the user is reminded of motor overheating and advised to slow down the vehicle and avoid frequent start-stop operations. When the current temperature approaches the highest motor temperature threshold, i.e., the third motor temperature threshold T3, the user is reminded of severe motor overheating, warned that the vehicle may be about to automatically shut down for protection, and advised to slow down the vehicle or immediately park it in a safe area.

[0103] Specifically, when it is detected that the current temperature (T3-T0) is less than 5°C, that is, when the current temperature differs from the third motor temperature threshold T3 by less than 5°C, a serious motor overtemperature warning may be issued.

[0104] Step S13: Acquire a corresponding shift curve according to the shift mode.

[0105] The step S13 specifically includes:

[0106] S131, correspondence between shift patterns and shift curves, and relationship between shift curves:

[0107] In one embodiment of the present application, obtaining a corresponding shift curve according to the shift mode includes:

[0108] acquiring a first shift curve according to the first shift pattern;

[0109] acquiring a second shift curve according to the second shift pattern;

[0110] acquiring a third shift curve according to the third shift pattern;

[0111] acquiring a fourth shift curve according to the fourth shift pattern;

[0112] Among them, from the first shift curve to the fourth shift curve, any shift curve achieves at least one of the following control functions compared with the previous shift curve: reducing the shift frequency, reducing the motor power, reducing the vehicle's driving acceleration, and reducing the vehicle's driving speed upper limit.

[0113] Specifically, from the first shift curve to the fourth shift curve, any shift curve can reduce the heat generated by the motor by reducing the shift frequency, reducing the motor power, reducing the vehicle's driving acceleration, and reducing the vehicle's driving speed upper limit compared to the previous shift curve.

[0114] In this embodiment, different shift modes correspond to different power output principles. Therefore, the shift curves corresponding to each shift mode have different improvement directions for the heat generation of the motor based on different power output principles. That is, the shift control strategies and control methods adopted by different shift curves are different, and the effects achieved in reducing the motor temperature are also different for different temperature scenarios.

[0115] S132, method for presetting the shift curve:

[0116] In one embodiment of the present application, presetting a first shift curve includes: presetting the first shift curve based on an optimal principle of vehicle power and economy, wherein the first shift curve is used to control the motor to maintain vehicle power, economy, and drivability;

[0117] According to the optimization principle of the motor heat generation, a second shift curve is pre-set, wherein the second shift curve causes the motor to operate in a low-loss working area to reduce the heat generation of the motor;

[0118] According to the principle of maintaining the minimum power of the whole vehicle, a third shift curve is pre-set, and the third shift curve is used to limit the motor output and the driving torque to maintain the minimum power of the whole vehicle;

[0119] According to the motor demagnetization protection principle, a fourth shift curve is preset, and the fourth shift curve is used to control the motor shutdown protection.

[0120] S132-1, method for presetting the first shift curve:

[0121] Among them, the first shift curve is set according to the shift control strategy during normal operation of the vehicle, which controls the motor to maintain the power, economy and drivability of the vehicle. The existing related technologies are relatively mature and will not be repeated here.

[0122] S132-2, method for presetting the second shift curve:

[0123] In one embodiment of the present application, the second shift curve can reduce the shift frequency and / or reduce the motor power compared to the first shift curve.

[0124] Generally speaking, based on the motor's loss characteristics, the higher the motor power, the greater the motor loss. The lost energy is converted into heat and dissipated, increasing the motor's heat generation and causing the motor temperature to rise. Therefore, appropriately reducing the motor power can reduce the motor's heat generation and, in turn, the motor temperature, or at least slow down the rise in motor temperature.

[0125] In addition, in the existing related technologies, AMT will simulate the driver's needs and shift gears according to the opening of the accelerator pedal (throttle opening) and the vehicle's driving speed. When the opening of the accelerator pedal and the vehicle's driving speed reach the shift threshold, a shift instruction is provided to perform the shift operation.

[0126] Therefore, when users frequently accelerate and decelerate using the accelerator pedal, the frequency of gear shifting increases accordingly. The current common AMT shifting method requires at least a sequence of torque reduction, gear shifting (neutral), gear selection, gear shifting, and torque increase to complete the shift operation. Due to motor loss characteristics and the influence of mechanical heat generation, frequent gear shifting will lead to increased motor heat generation.

[0127] In view of this, the second shift curve in the embodiment of the present application limits the frequency of shifts, reducing the shift frequency to reduce motor heat generation. This includes: increasing the shift threshold for upshifting operations, lowering the shift threshold for downshifting operations, and / or delaying the corresponding shift operations.

[0128] The shift threshold for upshifts is increased, while the shift threshold for downshifts is decreased. This means that the accelerator pedal opening and vehicle speed requirements for reaching the shift thresholds are increased. While the vehicle is driving, the accelerator pedal opening and vehicle speed are monitored. When the values reach the shift thresholds, a shift is initiated to accommodate the driver's acceleration or deceleration needs. Compared to the first shift curve, the second shift curve increases the shift threshold for upshifts and decreases the shift threshold for downshifts, thereby providing shift commands and completing the shifts. Specifically, in the second shift curve, the required vehicle speed for upshifts is increased by 0-10 km / h, while the required vehicle speed for downshifts is decreased by 0-10 km / h. The accelerator pedal opening required for upshifts is increased by 0-1 / 4, while the required accelerator pedal opening for downshifts is decreased by 0-1 / 4.

[0129] For example, let's assume the vehicle is currently in third gear. In the first shift mode, if the vehicle's speed reaches 40 km / h and the accelerator pedal is at 3 / 5 of its full width (i.e., the driver has pressed the accelerator pedal at 3 / 5 of its full width), the AMT transmission controller will issue a shift command based on the first shift profile, increasing the motor power and speed to shift the transmission to fourth gear. In the second shift mode, if the vehicle's speed reaches 45 km / h and the accelerator pedal is at 4 / 5 of its full width (i.e., the driver has pressed the accelerator pedal at 4 / 5 of its full width), the AMT transmission controller will issue a shift command based on the second shift profile, increasing the motor power and speed to shift the transmission to fourth gear.

[0130] The corresponding shift operation is delayed, i.e., sensitivity to accelerator pedal position and vehicle speed is reduced, delaying the shift operation and thus reducing shift frequency. Specifically, after detecting that the accelerator pedal position and vehicle speed have reached a shift threshold, the shift command can be issued with a delay of 0-10 seconds. During this delay, the accelerator pedal position and vehicle speed can be monitored to see if they meet the shift threshold. This includes monitoring the accelerator pedal position and vehicle speed again before issuing the shift command to see if they meet the shift threshold. If so, the shift command is immediately executed. For example, assume the vehicle is currently in third gear. In the first shift mode, if the vehicle speed reaches 40 kilometers per hour and the accelerator pedal position reaches 3 / 5 (i.e., the driver has pressed the accelerator 3 / 5 of the way down), the AMT transmission controller immediately issues a shift command based on the first shift profile, increasing the motor power and speed to shift the transmission to fourth gear. In the second shift mode, if it is detected that the vehicle speed reaches 40 kilometers per hour and the accelerator pedal opening reaches 3 / 5 (that is, the driver presses the accelerator to a depth of 3 / 5), the AMT transmission controller will delay for 5 seconds based on the second shift curve and monitor again whether the accelerator pedal opening reaches 3 / 5 and the vehicle speed reaches 40 kilometers per hour. If so, it will issue a shift command to increase the motor power and speed and switch the transmission to the fourth gear.

[0131] S132-3, method for presetting the third shift curve:

[0132] In one embodiment of the present application, the third shift curve, compared with the second shift curve, implements at least one of the following control functions: reducing the vehicle's driving acceleration, and reducing the vehicle's driving speed upper limit.

[0133] The third shift curve reduces the vehicle's acceleration and / or upper speed limit, building on the reduced shift frequency and / or motor power achieved in the second shift curve. This can further limit motor heat generation during vehicle operation. Specifically, all other conditions being equal, the third shift curve limits the vehicle's acceleration to 0-1 times the vehicle's acceleration in the second shift curve, and the third shift curve limits the vehicle's upper speed limit to 0-1 times the vehicle's speed in the second shift curve. Lowering the vehicle's upper speed limit and operating the vehicle in a low gear, such as first or second gear, further reduces motor temperature. For example, assuming that in the second shift mode, the second shift curve limits the vehicle's maximum acceleration to 5 m / s², in the third shift mode, the third shift curve can limit the vehicle's maximum acceleration to 0.2 times the maximum acceleration set by the second shift curve, i.e., 1 m / s².2 Assuming that in the second shift mode, the second shift curve limits the vehicle's upper speed limit to 120 kilometers per hour, then in the third shift mode, the third shift curve can limit the vehicle's upper speed limit to 0.3 times the vehicle's upper speed limit defined by the second shift curve, that is, 36 kilometers per hour.

[0134] S132-4, method for presetting the fourth shift curve:

[0135] In existing related technologies, when the motor temperature exceeds the automatic shutdown protection temperature threshold built into the motor controller, the motor may undergo a sudden power drop or sudden shutdown protection, which may cause the vehicle to lose control and pose a safety hazard.

[0136] In one embodiment of the present application, the third temperature threshold T3 is set to be smaller than the automatic shutdown protection temperature threshold Ts built into the motor controller. After the motor temperature exceeds the third temperature threshold T3, the AMT transmission controller performs shift control based on the fourth shift curve, and sends a torque gradient control mode request to the drive motor controller. The motor controller controls the output torque of the drive motor to drop smoothly to zero, that is, before the motor controller controls the motor to automatically shut down for protection, the motor torque is allowed to drop smoothly to avoid sudden automatic shutdown protection of the motor.

[0137] S133, shift curve correction, including:

[0138] In the embodiment of the present application, according to the shifting mode, a corresponding initial shifting curve is obtained, and the initial shifting curve includes: a first initial shifting curve, a second initial shifting curve, a third initial shifting curve, and a fourth initial shifting curve;

[0139] Based on the power output principle of the current shift mode, obtain the corresponding curve correction factor;

[0140] Correcting the initial shift curve according to the curve correction factor to obtain a corresponding shift curve;

[0141] The curve correction factor includes at least any one of the following: a motor efficiency map, a current speed of the vehicle, a current acceleration of the vehicle, and a minimum driving torque required by the vehicle.

[0142] In the embodiment of the present application, the initial shift curve can be

[0143] In one embodiment of the present application, according to the optimization principle of the motor heat amount, a motor efficiency map is obtained, and according to the motor efficiency map, the initial shift curve is corrected to obtain the shift curve.

[0144] In one embodiment of the present application, the second initial shift curve is corrected based on the motor efficiency map to obtain a second shift curve, so that the second shift curve controls the motor as the final shift curve, and based on the shift curve, the output of the power system is controlled.

[0145] S13-1, correction of the second shift curve, including:

[0146] The machine should operate in the motor's high efficiency working area as much as possible.

[0147] Figure 2 It is a motor efficiency map. Figure 2 As shown, the embodiment of the present application is based on the second shift curve. On the premise of meeting driving needs, by adjusting the torque T and the motor speed n, the motor is controlled to operate within a range of working efficiency greater than 85%, thereby reducing the energy loss of the motor, and then reducing the heat generated by the motor, slowing down the rate of increase of the motor temperature or lowering the motor temperature.

[0148] S13-3, correction for the third shift curve, including:

[0149] In one embodiment of the present application, based on the principle of maintaining the minimum power of the entire vehicle, the current speed of the entire vehicle, the current acceleration of the entire vehicle, and the minimum driving torque required by the entire vehicle are obtained. According to the current speed of the entire vehicle, the current acceleration of the entire vehicle, and the minimum driving torque required by the entire vehicle, the initial shift curve is corrected to obtain the shift curve.

[0150] Specifically, the process includes: calculating the upper limit of the motor speed, n, based on the vehicle's upper speed limit and maximum acceleration set by the initial shift curve; calculating the minimum required driving torque, T, based on the vehicle's current speed and acceleration, as well as the minimum power required to maintain vehicle operation; setting the minimum motor power based on the formula T = 9550*P / n, combined with motor efficiency and vehicle power loss parameters, to maintain the vehicle's minimum operating power; and formulating the shift curve based on the minimum motor power. This allows the vehicle to travel at a very low speed while maintaining forward momentum. On the one hand, the third shift curve reduces the vehicle's maximum acceleration and upper speed limit to limit the motor speed and power, significantly reducing motor heat generation and preventing further temperature increases that could lead to shutdown protection. On the other hand, the third shift curve sets the minimum required driving torque to maintain the vehicle's minimum operating power and prevent uncontrolled sliding (i.e., rolling down a slope), which could create a safety hazard. The minimum driving torque, defined as the torque required to meet the vehicle's power requirements, is set based on different driving scenarios. For example, for the same vehicle model, the minimum driving torque required to maintain low speed on a flat road might be 30 N·m; while the minimum driving torque required to maintain low speed on an uphill road might be 100 N·m.

[0151] Step S14: performing a shift operation based on the shift curve, and controlling the power system to complete corresponding power output.

[0152] In this embodiment, the AMT transmission controller controls the power output based on the current shift curve, that is, based on the shift curve, according to the opening of the accelerator pedal and the current vehicle speed, when it is determined that a gear shift is required, the gear shift operation is performed, and then the power system is controlled to complete the corresponding power output.

[0153] Figure 3 A flow chart of a method for formulating a shift strategy based on motor temperature according to an embodiment of the present application is shown. Figure 3As shown, the first step is to obtain the current temperature of the motor; the second step is to determine whether the current temperature is less than the first temperature threshold T1 through the transmission controller. If so, the normal shift mode is enabled and the process goes to the sixth step, otherwise it goes to the third step; the third step is to determine whether the current temperature is less than the second temperature threshold T2. If so, the optimized motor output shift mode is enabled and the process goes to the sixth step, otherwise it goes to the fourth step; the fourth step is to determine whether the current temperature is less than the second temperature threshold T3. If so, the motor output shift mode is limited and the process goes to the sixth step, otherwise the shutdown protection mode is enabled and the process goes to the sixth step; the sixth step is to specify a corresponding shift strategy according to the enabled shift mode, and the shift strategy corresponds to different shift curves; the seventh step is to perform a shift operation according to the shift curve.

[0154] In this embodiment, motor temperature thresholds are set based on the heat-resistance characteristics of each motor type for each vehicle model. A corresponding shift pattern and corresponding shift curve are set based on the vehicle performance parameters of each motor type for each vehicle model. After each vehicle is assembled, each vehicle is individually tested. Based on the test results, the pre-set motor temperature thresholds, shift patterns, and shift curves can be adjusted accordingly.

[0155] After the vehicle has been used for a period of time, technicians can also adjust the motor temperature threshold or curve correction factor based on the vehicle's overall performance loss and motor loss.

[0156] This embodiment can implement the above-mentioned technical solution provided by the embodiment of the present application by adding a control algorithm on the basis of the existing transmission controller, without modifying the existing hardware or adding additional hardware, thus saving hardware costs.

[0157] Those skilled in the art will understand that the embodiments of the present application can be applied to various types of electric vehicles. Due to the differences in power models, there will be more or less differences in the specific configuration and implementation methods of the shifting function in different power systems. In one embodiment provided in the present application, it can be applied to the AMT transmission controller of an electric vehicle, and it can also be applied to the speed control system of an electric vehicle, and it can also be applied to the whole vehicle control system or whole vehicle controller of an electric vehicle.

[0158] Figure 4 This is a structural block diagram of a shifting device proposed in an embodiment of the present application. Figure 4 As shown, the device includes:

[0159] The temperature acquisition module 51 is used to obtain the current temperature of the motor;

[0160] A mode acquisition module 52 is configured to acquire a shift mode corresponding to the current motor temperature according to a preset motor temperature threshold;

[0161] The mode acquisition module 52 includes the following submodules:

[0162] A first shift mode acquiring module 52 - 1 , configured to acquire a first shift mode when the current temperature does not exceed a first motor temperature threshold T1 ;

[0163] A second shift mode acquiring module 52 - 2 , configured to acquire a second shift mode when the current temperature exceeds a first motor temperature threshold T1 and does not exceed a second motor temperature threshold T2 ;

[0164] A third shift mode acquiring module 52 - 3 , configured to acquire a third shift mode when the current temperature exceeds the second motor temperature threshold T2 and does not exceed the third motor temperature threshold T3 ;

[0165] The fourth shift mode acquiring module 52 - 4 is configured to acquire a fourth shift mode when the current temperature exceeds a third motor temperature threshold T3 .

[0166] A curve acquisition module 53 is used to acquire a corresponding shift curve according to the shift mode;

[0167] The curve acquisition module 53 includes the following submodules:

[0168] A first shift curve acquiring module 53-1 is configured to acquire a first shift curve according to the first shift pattern;

[0169] A second shift curve acquiring module 53-2, configured to acquire a second shift curve according to the second shift pattern;

[0170] A third shift curve acquiring module 53 - 3 , configured to acquire a third shift curve according to the third shift mode;

[0171] a fourth shift curve acquiring module 53 - 4 , configured to acquire a fourth shift curve according to the fourth shift mode;

[0172] Among them, from the first shift curve to the fourth shift curve, any shift curve achieves at least one of the following control functions compared with the previous shift curve: reducing the shift frequency, reducing the motor power, reducing the vehicle's driving acceleration, and reducing the vehicle's driving speed upper limit.

[0173] In one embodiment of the present application, the device further includes a shift curve preset module 54, and the shift curve preset module 54 includes the following submodules:

[0174] A first shift curve presetting module 54-1 is configured to pre-set a first shift curve, including: pre-setting the first shift curve based on an optimal principle of vehicle power and economy, wherein the first shift curve is configured to control the motor to maintain vehicle power, economy, and drivability;

[0175] a second shift curve presetting module 54-2, configured to pre-set a second shift curve based on a principle of optimizing motor heat generation, wherein the second shift curve causes the motor to operate in a low-loss operating range to reduce motor heat generation;

[0176] A third shift curve presetting module 54-3 is used to pre-set a third shift curve based on the principle of maintaining the minimum power of the entire vehicle. The third shift curve is used to limit the motor output and the driving torque to maintain the minimum power of the entire vehicle;

[0177] The fourth shift curve preset module 54 - 4 is used to preset a fourth shift curve according to the motor demagnetization protection principle, and the fourth shift curve is used to control the motor shutdown protection.

[0178] In one embodiment of the present application, the curve acquisition module 53 further includes the following submodules:

[0179] An initial shift curve acquisition module 53 - 11 is configured to acquire a corresponding initial shift curve according to the shift mode, wherein the initial shift curves include: a first initial shift curve, a second initial shift curve, a third initial shift curve, and a fourth initial shift curve;

[0180] The curve correction factor acquisition module 53-12 is used to obtain the corresponding curve correction factor based on the power output principle of the current shift mode;

[0181] a curve correction module 53 - 13 , configured to correct the initial shift curve according to the curve correction factor to obtain a corresponding shift curve;

[0182] The curve correction factor includes at least any one of the following: a motor efficiency map, a current speed of the vehicle, a current acceleration of the vehicle, and a minimum driving torque required by the vehicle.

[0183] The curve correction module 53-13 further includes:

[0184] The second curve correction module 53-13-2 is used to obtain a motor efficiency map according to the optimization principle of motor heat generation, and correct the initial shift curve according to the motor efficiency map to obtain the shift curve.

[0185] The third curve correction module 53-13-3 is used to obtain the current speed of the vehicle, the current acceleration of the vehicle, and the minimum driving torque required by the vehicle based on the principle of maintaining the minimum power of the vehicle, and correct the initial shift curve according to the current speed of the vehicle, the current acceleration of the vehicle, and the minimum driving torque required by the vehicle to obtain the shift curve.

[0186] The third curve correction module 53-13-3 further includes:

[0187] The motor speed upper limit n is calculated based on the vehicle's driving speed upper limit and the vehicle's maximum driving acceleration set by the initial shift curve; the minimum driving torque T required for the vehicle is calculated based on the current speed and current acceleration of the vehicle, as well as the minimum power requirement for the vehicle to maintain operation; based on the formula T=9550*P / n, combined with the motor efficiency and the vehicle's power loss parameters, the minimum motor power is set to maintain the minimum operating power of the vehicle; and the shift curve is formulated based on the minimum motor power.

[0188] The output control module 54 is configured to execute a shift operation based on the shift curve and control the power system to achieve corresponding power output.

[0189] Based on the same inventive concept, another embodiment of the present application provides a vehicle, which includes an AMT transmission controller. When the AMT transmission controller is executed, the steps in the method described in any of the above embodiments of the present application are implemented.

[0190] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other.

[0191] It should also be noted that, in this article, the orientation or position relationship indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations, nor can they be understood as indicating or implying relative importance. Moreover, the terms "include", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device that includes a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, an element defined by the phrase "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or terminal device that includes the element.

[0192] The technical solutions provided by this application are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of this application. The description of the above embodiments is only intended to help understand this application, and the contents of this specification should not be construed as limiting this application. At the same time, for those skilled in the art, according to this application, there may be various changes in the specific implementation methods and application scopes. It is not necessary and impossible to list all implementation methods here, and obvious changes or modifications derived therefrom are still within the scope of protection of this application.

Claims

1. A shifting method, characterized in that: Applied to an AMT transmission controller, the method includes: Get the current temperature of the motor; According to a preset motor temperature threshold, obtaining a shift mode corresponding to the current temperature; According to the shifting mode, obtaining a corresponding shifting curve; Executing a shift operation based on the shift curve and controlling the power system to achieve corresponding power output; Wherein, according to the shifting mode, obtaining a corresponding shifting curve includes: According to the shifting mode, obtaining a corresponding initial shifting curve; Based on the power output principle of the current shift mode, obtain the corresponding curve correction factor; The initial shift curve is corrected according to the curve correction factor to obtain a corresponding shift curve; wherein different shift modes correspond to different power output principles.

2. The method according to claim 1, characterized in that Acquiring a shift mode corresponding to the current temperature according to a preset motor temperature threshold includes: When the current temperature does not exceed the first motor temperature threshold T1, obtaining a first shift mode; When the current temperature exceeds a first motor temperature threshold T1 and does not exceed a second motor temperature threshold T2, acquiring a second shift mode; When the current temperature exceeds the second motor temperature threshold T2 and does not exceed the third motor temperature threshold T3, acquiring a third shift mode; When the current temperature exceeds the third motor temperature threshold T3, a fourth shift mode is acquired.

3. The method according to claim 2, characterized in that According to the shifting mode, a corresponding shifting curve is obtained, including: acquiring a first shift curve according to the first shift pattern; acquiring a second shift curve according to the second shift pattern; acquiring a third shift curve according to the third shift pattern; acquiring a fourth shift curve according to the fourth shift pattern; Among them, from the first shift curve to the fourth shift curve, any shift curve achieves at least one of the following control functions compared with the previous shift curve: reducing the shift frequency, reducing the motor power, reducing the vehicle's driving acceleration, and reducing the vehicle's driving speed upper limit.

4. The method according to claim 1, wherein Also includes: Presetting a first shift curve includes: presetting the first shift curve based on an optimal principle of vehicle power and economy, wherein the first shift curve is used to control the motor to maintain vehicle power, economy, and drivability; According to the optimization principle of the motor heat generation, a second shift curve is pre-set, wherein the second shift curve causes the motor to operate in a low-loss working area to reduce the heat generation of the motor; According to the principle of maintaining the minimum power of the whole vehicle, a third shift curve is pre-set, and the third shift curve is used to limit the motor output and the driving torque to maintain the minimum power of the whole vehicle; According to the motor demagnetization protection principle, a fourth shift curve is preset, and the fourth shift curve is used to control the motor shutdown protection.

5. The method according to claim 1, wherein The curve correction factor includes at least any one of the following: a motor efficiency map, a current speed of the vehicle, a current acceleration of the vehicle, and a minimum driving torque required by the vehicle.

6. The method according to claim 5, characterized in that Based on the power output principle of the current shift mode, a corresponding curve correction factor is obtained, and the initial shift curve is corrected according to the curve correction factor to obtain a corresponding shift curve, including: According to the optimization principle of the motor heat amount, a motor efficiency map is obtained, and the initial shift curve is corrected according to the motor efficiency map to obtain the shift curve.

7. The method according to claim 5, characterized in that Based on the power output principle of the current shift mode, a corresponding curve correction factor is obtained, and the initial shift curve is corrected according to the curve correction factor to obtain a corresponding shift curve, including: According to the principle of maintaining the minimum power of the whole vehicle, the current speed of the whole vehicle, the current acceleration of the whole vehicle, and the minimum driving torque required by the whole vehicle are obtained. According to the current speed of the whole vehicle, the current acceleration of the whole vehicle, and the minimum driving torque required by the whole vehicle, the initial shift curve is corrected to obtain the shift curve.

8. The method according to claim 7, characterized in that Also includes: Calculating the upper limit n of the motor speed according to the upper limit of the vehicle speed set by the initial shift curve and the maximum acceleration of the vehicle; Calculate the minimum driving torque T required for the vehicle based on the current speed and acceleration of the vehicle and the minimum power requirement for the vehicle to keep running; Based on the formula T = 9550*P / n, combined with motor efficiency and vehicle power loss parameters, the minimum motor power is set to maintain the minimum operating power of the vehicle; The shift curve is formulated based on the minimum power of the motor.

9. A gear shifting device, characterized in that: Applied to an AMT transmission controller, the device includes: Temperature acquisition module, used to obtain the current temperature of the motor; A mode acquisition module, configured to acquire a shift mode corresponding to the current motor temperature according to a preset motor temperature threshold; A curve acquisition module, configured to acquire a corresponding shift curve according to the shift mode; an output control module, configured to execute a shift operation based on the shift curve and control the power system to achieve corresponding power output; Wherein, the mode acquisition module includes: An initial shift curve acquisition module, configured to acquire a corresponding initial shift curve according to the shift mode; A curve correction factor acquisition module is used to obtain a corresponding curve correction factor based on the power output principle of the current shift mode, wherein different shift modes correspond to different power output principles; The curve correction module is used to correct the initial shift curve according to the curve correction factor to obtain a corresponding shift curve.

10. A vehicle, characterized in that: The vehicle includes an AMT transmission controller, and the AMT transmission controller, when executed, implements the steps of the method according to any one of claims 1 to 7.

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