A shift speed control method and device of a dual-motor driving system and a vehicle

Abstract

The embodiment of the application discloses a gear shifting speed regulation control method and device of a double-motor driving system and a vehicle. The double-motor driving system comprises a first motor and a second motor, and is used for driving the vehicle to run by the first motor. When the second motor is in gear shifting, the speed of the second motor is controlled to complete the gear shifting. The gear shifting speed regulation control method comprises the following steps: determining the current running state of the vehicle according to the running state of the first motor; determining a target speed compensation value of the second motor according to the running state and a target gear position of the second motor; and adjusting the speed of the second motor according to the target speed compensation value, so that the speed of the second motor matches the target gear position. The technical scheme of the embodiment of the application can solve the problem that the gear shifting fails due to the too large difference between the real-time speed of the motor and the synchronous meshing speed of the motor when the second motor is in gear shifting, and improves the gear shifting stability of the second motor.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a method, device, and vehicle for shifting and speed control of a dual-motor drive system. Background Technology

[0002] With social development, pure electric vehicles and hybrid vehicles, including those driven by electric motors, are becoming increasingly widespread. Currently, many electric commercial vehicles use two- or multi-speed transmissions to meet the demands of power at low speeds and economy at high speeds. When commercial electric vehicles use clutchless mechanical shifting mechanisms (similar to AMT solutions), power interruption occurs during gear shifts, resulting in a poor driving experience. Therefore, a dual-motor drive configuration is gradually emerging in the industry. When one motor needs to upshift, the other motor maintains drive, thus addressing both the need for uninterrupted power during gear shifts and the requirement to optimize motor operating points over a wider range.

[0003] However, when one motor is accelerating or decelerating while the other is shifting gears, the synchronous control of the shifting motor's speed becomes crucial. For example, if one of the dual motors in the system is in gear driving acceleration or deceleration, the other motor needs to be disengaged from neutral to adjust its speed and then engage gear to drive the vehicle when it reaches the shifting condition. After adjusting its speed in neutral, the motor will enter a zero-torque mode, and the shift fork will simultaneously engage the gear. In zero-torque mode, the motor's speed will drop freely. If the other motor is accelerating or decelerating at this time, the difference between the real-time speed of the shifting motor and the synchronous engagement speed will be too large. This will cause the shifting actuator to fail to engage the gear when pushing the shift fork into the gear due to the excessive speed difference. Summary of the Invention

[0004] This invention provides a shifting speed control method, device, and vehicle for a dual-motor drive system. The shifting speed control method determines the target speed compensation value of the second motor that needs to shift gears based on the operating state of the first motor that is in gear. The speed of the second motor is compensated according to the target speed compensation value to solve the problem of shifting failure caused by the large difference between the real-time speed of the second motor and the synchronous meshing speed of the motor during shifting, thereby improving the shifting stability of the second motor.

[0005] According to one aspect of the present invention, a shifting speed control method for a dual-motor drive system is provided. The dual-motor drive system includes a first motor and a second motor, used to control the rotational speed of the second motor to complete the shifting when the first motor drives the vehicle and the second motor shifts gears; the shifting speed control method includes:

[0006] The current driving status of the vehicle is determined based on the operating status of the first motor;

[0007] Based on the driving state and the target gear of the second motor, determine the target speed compensation value of the second motor;

[0008] The speed of the second motor is adjusted according to the target speed compensation value so that the speed of the second motor matches the target gear.

[0009] Optionally, determining the current driving state of the vehicle based on the operating state of the first motor includes:

[0010] The rotational speed of the first motor is acquired multiple times within a preset time period;

[0011] The rate of change of the first motor speed is determined based on multiple speeds of the first motor.

[0012] The current driving state of the vehicle is determined based on the rate of change of rotational speed.

[0013] Optionally, the driving state includes acceleration state, deceleration state, and steady speed state;

[0014] Determining the vehicle's current driving state based on the rate of change of rotational speed includes:

[0015] If the rate of change of rotational speed is greater than or equal to the first threshold M times within a preset time, the vehicle is determined to be in an acceleration state.

[0016] If the rate of change of rotational speed is less than or equal to the second threshold N times within a preset time, the vehicle is determined to be in a deceleration state.

[0017] If the rate of change of rotational speed is between the first threshold and the second threshold P times within a preset time, the vehicle is determined to be in a steady-speed state.

[0018] Wherein, the first threshold is a positive value, the second threshold is a negative value, and M, N, and P are all integers greater than or equal to 1.

[0019] Optionally, the first threshold is different when the first motor is in different gears, and the first threshold is proportional to the speed ratio of the gear in which the first motor is in.

[0020] The second threshold value varies depending on the gear position of the first motor. The second threshold value is inversely proportional to the speed ratio of the gear position of the first motor.

[0021] Optionally, determining the target speed compensation value of the second motor based on the driving state and the target gear of the second motor includes:

[0022] Determine whether the driving state is an acceleration state, a deceleration state, or a steady speed state;

[0023] If the driving state is determined to be either an acceleration state or a deceleration state, then the target speed compensation value is calculated based on the speed of the first motor and the target gear.

[0024] Optionally, the method for calculating the target speed compensation value includes:

[0025] Determine the rate of change of the first motor's speed based on the first motor's speed;

[0026] Based on the speed change rate, determine the change in the speed of the first motor Δn per unit time;

[0027] according to Calculate the target rotational speed compensation value;

[0028] Wherein, R1 represents the gear ratio of the first motor, R2 represents the target gear ratio of the second motor, and T represents the average time from the start of the second motor speed adjustment to the moment the shift fork push-engage sleeve reaches the tooth engagement position.

[0029] Optionally, after determining whether the driving state is an acceleration state, a deceleration state, or a steady speed state, the method further includes:

[0030] If the driving state is determined to be a steady speed state, then the target speed compensation value is 0.

[0031] Optionally, the target speed compensation value is locked as a fixed value when the second motor is adjusted.

[0032] According to another aspect of the present invention, a shift speed control device for a dual-motor drive system is provided for executing the above-described shift speed control method for a dual-motor drive system, the shift speed control device comprising:

[0033] The driving status determination module is used to determine the current driving status of the vehicle based on the operating status of the first motor.

[0034] The compensation value determination module is used to determine the target speed compensation value of the second motor based on the driving state and the target gear of the second motor.

[0035] The compensation module is used to adjust the speed of the second motor according to the target speed compensation value so that the speed of the second motor matches the target gear.

[0036] According to another aspect of the present invention, a vehicle is provided, including a dual-motor drive system and the aforementioned gear shifting speed control device.

[0037] The present invention provides a shifting speed control method for a dual-motor drive system. The dual-motor drive system includes a first motor and a second motor. The first motor drives the vehicle, and when the second motor shifts gears, the method controls the speed of the second motor to complete the shift. The shifting speed control method first determines the current driving state of the vehicle based on the operating state of the first motor; then, based on the driving state and the target gear of the second motor, it determines a target speed compensation value for the second motor; finally, it adjusts the speed of the second motor according to the target speed compensation value to match the target gear. This technical solution can solve the problem that when the second motor shifts gears, the difference between the real-time speed and the synchronous meshing speed is too large, causing the shifting actuator to fail to engage gears due to the excessive speed difference when pushing the shift fork, thus improving the shifting stability of the second motor.

[0038] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 A flowchart illustrating a shifting speed control method for a dual-motor drive system provided in an embodiment of the present invention;

[0041] Figure 2 A schematic diagram of a process for determining the driving status of a vehicle, provided as an embodiment of the present invention;

[0042] Figure 3 This is a schematic flowchart illustrating the process of determining the target speed compensation value of a second motor, as provided in an embodiment of the present invention.

[0043] Figure 4 This is a schematic diagram illustrating the specific calculation process of a target speed compensation value provided in an embodiment of the present invention;

[0044] Figure 5 This is a schematic diagram of the structure of a shifting speed control device for a dual-motor drive system provided in an embodiment of the present invention. Detailed Implementation

[0045] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0046] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0047] Figure 1 This is a flowchart illustrating a shift speed control method for a dual-motor drive system according to an embodiment of the present invention. This shift speed control method can be executed by software and / or, for example, by a controller responsible for the coordinated control of the two drive motors. The dual-motor drive system includes a first motor and a second motor. The first motor drives the vehicle, and when the second motor shifts gears, the speed of the second motor is controlled to complete the shift. (See reference...) Figure 1 The shift speed control method includes:

[0048] S110. Determine the current driving status of the vehicle based on the operating status of the first motor.

[0049] The operating state of the first motor includes the rotational speed of the first motor, and the current driving state of the vehicle includes acceleration, deceleration and constant speed driving. Since it is difficult for a vehicle to maintain a truly constant speed, its speed change rate is considered to be in a constant speed state if it is stable within a certain range. The specific speed change rate can be determined according to the actual situation, and this embodiment of the invention does not limit it.

[0050] In practice, whether the vehicle is in an acceleration or deceleration state can be determined based on the rate of change of the first motor's rotational speed per unit time. Figure 2 This is a flowchart illustrating a process for determining the driving state of a vehicle, as provided in an embodiment of the present invention. Figure 2 Optionally, the current driving state of the vehicle can be determined based on the operating state of the first motor, including:

[0051] S111. Within a preset time period, the rotational speed of the first motor is acquired multiple times;

[0052] S112. Determine the rate of change of the speed of the first motor based on the multiple speeds of the first motor;

[0053] S113. Determine the current driving status of the vehicle based on the rate of change of rotational speed.

[0054] The preset time period can be flexibly selected according to actual conditions. When calculating the rate of change of motor speed, the accuracy of the data can be improved by filtering. For example, in one embodiment, the sampling period for motor speed is 1ms. To improve accuracy, the average of 5 consecutive samples within 5ms can be used as the filtered motor speed, and the unit time difference of the filtered motor speed can be used as the rate of change of the first motor speed, where the unit time can be 10ms.

[0055] Optionally, the driving state includes acceleration, deceleration, and steady-speed states; the current driving state of the vehicle is determined based on the rate of change of engine speed, including:

[0056] If the rate of change of engine speed is greater than or equal to the first threshold M times within a preset time, the vehicle is determined to be in an acceleration state; if the rate of change of engine speed is less than or equal to the second threshold N times within a preset time, the vehicle is determined to be in a deceleration state; if the rate of change of engine speed is between the first and second thresholds P times within a preset time, the vehicle is determined to be in a steady speed state.

[0057] The first threshold is a positive value, the second threshold is a negative value, and M, N, and P are all integers greater than or equal to 1.

[0058] It is understandable that when the rate of change of rotational speed is positive, it indicates that the speed of the first motor is increasing over time, and the vehicle is accelerating; when the rate of change of rotational speed is negative, it indicates that the speed of the first motor is decreasing over time, and the vehicle is decelerating. When the rate of change of rotational speed is within a certain positive and negative limit range, it indicates that the vehicle is in a state close to stable driving. To improve the accuracy of judging the vehicle's driving state, multiple judgments can be used, where the values ​​of M, N, and P can be set according to actual needs. For example, in a specific embodiment, when the real-time value of the rate of change of rotational speed of the first motor exceeds a first threshold, such as value A, for a specified number of consecutive times, such as 3 times, it is judged as an acceleration state; when the real-time value of the rate of change of rotational speed of the first motor is less than a second threshold, such as value B, for a specified number of consecutive times, such as 3 times, it is judged as a deceleration state; when the motor is in an acceleration or deceleration state, and its real-time value of the rate of change of rotational speed is between value B and value A for a specified number of consecutive times, such as 3 times, it is re-judged as a steady-speed state.

[0059] The absolute value of the real-time value of the filtered rate of change of the motor speed of the first motor varies depending on the gear position, and the limit value is directly proportional to the speed ratio of the corresponding gear. Optionally, the first threshold value is different when the first motor is in different gears, and the first threshold value is directly proportional to the speed ratio of the gear position of the first motor; the second threshold value is different when the first motor is in different gears, and the second threshold value is inversely proportional to the speed ratio of the gear position of the first motor.

[0060] It is understandable that the second threshold is negative. The higher the speed ratio of the gear in which the first motor is located, the larger the absolute value of the second threshold. Therefore, the second threshold is inversely proportional to the speed ratio of the gear in which the first motor is located.

[0061] S120. Determine the target speed compensation value of the second motor based on the driving status and the target gear of the second motor.

[0062] Understandably, when a vehicle accelerates, the target gear of the second motor is usually a high gear, and when the vehicle decelerates, the target gear of the second motor is a low gear. Figure 3 This is a flowchart illustrating a method for determining the target speed compensation value of a second motor, as provided in an embodiment of the present invention. (Refer to...) Figure 3 Optionally, based on the driving conditions and the target gear of the second motor, the target speed compensation value of the second motor is determined, including:

[0063] S121. Determine whether the driving state is acceleration, deceleration, or steady speed.

[0064] The vehicle's driving status can be determined by the aforementioned steps based on the rate of change of the first motor's rotational speed.

[0065] S122. If the driving state is determined to be either acceleration or deceleration, the target speed compensation value is calculated based on the speed of the first motor and the target gear.

[0066] In this embodiment, optionally, the target speed compensation value is locked as a fixed value when the second motor speeds up. That is, the target speed compensation value of the second motor needs to be locked when the motor starts speed adjustment. In other words, the target speed compensation value of the second motor is locked at the beginning of speed adjustment and cannot be updated in real time during the speed adjustment phase. This helps to simplify the compensation method and avoid the system becoming too complex. Figure 4 This is a schematic diagram illustrating the specific calculation process of a target speed compensation value according to an embodiment of the present invention. (Refer to...) Figure 4 ,

[0067] Optionally, the calculation method for the target speed compensation value includes:

[0068] S1221. Determine the rate of change of the speed of the first motor based on the speed of the first motor.

[0069] The process for determining the rate of change of rotational speed can be found in the description of the foregoing embodiments, and will not be detailed here.

[0070] S1222. Determine the change in the speed of the first motor Δn per unit time based on the rate of change of speed.

[0071] In this embodiment, the unit time can be 10ms.

[0072] S1223, according to Calculate the target speed compensation value.

[0073] Wherein, R1 represents the gear ratio of the first motor, R2 represents the target gear ratio of the second motor, and T represents the average time from the start of the second motor's speed adjustment to the moment the shift fork reaches the engagement position.

[0074] Understandably, the real-time value of the first motor speed change Δn per unit time, after filtering, divided by the corresponding gear ratio R1, and then multiplied by the gear ratio R2 of the second motor corresponding to the target gear, is the expected real-time value of the second motor speed change at the desired gear per unit time. For the second motor in speed-adjustable gear shifting, the average time T (which can be pre-calibrated) from the completion of motor speed adjustment to the moment the shift fork reaches the engagement position is calculated. This average time T is multiplied by the expected real-time value of the second motor speed change at the desired gear per unit time, and used as the target motor speed compensation value for the second motor when the first motor drives the vehicle in an acceleration or deceleration state.

[0075] Optionally, after determining whether the driving state is an acceleration state, a deceleration state, or a steady speed state, it also includes;

[0076] S123. If the driving state is determined to be a steady speed state, the target speed compensation value is 0.

[0077] If the vehicle is at a constant speed, the compensation value can be set to 0, meaning no speed compensation will be performed.

[0078] S130. Adjust the speed of the second motor according to the target speed compensation value so that the speed of the second motor matches the target gear.

[0079] The technical solution of this invention can solve the problem that when the second motor shifts gears, the difference between the real-time speed of the motor and the synchronous meshing speed of the motor is too large, causing the shifting actuator to be unable to complete the gear engagement due to the large speed difference when pushing the shift fork into the gear teeth, thereby improving the shifting stability of the second motor.

[0080] Figure 5This is a schematic diagram of a shift speed control device for a dual-motor drive system provided in an embodiment of the present invention. This shift speed control device is used to execute any of the shift speed control methods for a dual-motor drive system provided in the above embodiments. (Refer to...) Figure 5 The shift speed control device includes:

[0081] The driving status determination module 10 is used to determine the current driving status of the vehicle based on the operating status of the first motor; the compensation value determination module 20 is used to determine the target speed compensation value of the second motor based on the driving status and the target gear of the second motor; the compensation module 30 is used to adjust the speed of the second motor based on the target speed compensation value so that the speed of the second motor matches the target gear.

[0082] Optionally, the driving status determination module 10 is specifically used for:

[0083] The rotational speed of the first motor is acquired multiple times within a preset time period;

[0084] Determine the rate of change of the first motor's speed based on multiple speeds of the first motor;

[0085] The current driving status of the vehicle is determined based on the rate of change of rotational speed.

[0086] Optionally, the driving state includes acceleration, deceleration, and steady-speed states; the driving state determination module 10 is also used for:

[0087] If the rate of change of rotational speed is greater than or equal to the first threshold M times within a preset time, the vehicle is determined to be in an acceleration state.

[0088] If the rate of change of rotational speed is less than or equal to the second threshold N times within a preset time, the vehicle is determined to be in a deceleration state.

[0089] If the rate of change of rotational speed is between the first threshold and the second threshold P times within a preset time, the vehicle is determined to be in a steady-speed state.

[0090] The first threshold is a positive value, the second threshold is a negative value, and M, N, and P are all integers greater than or equal to 1.

[0091] Optionally, the first threshold is different when the first motor is in different gears, and the first threshold is directly proportional to the speed ratio of the gear in which the first motor is in; the second threshold is different when the first motor is in different gears, and the second threshold is inversely proportional to the speed ratio of the gear in which the first motor is in.

[0092] Optionally, the compensation value determination module 20 is specifically used for:

[0093] Determine whether the driving state is accelerating, decelerating, or maintaining a steady speed.

[0094] If the driving state is determined to be either acceleration or deceleration, the target speed compensation value is calculated based on the speed of the first motor and the target gear.

[0095] Optionally, the calculation method for the target speed compensation value includes:

[0096] Determine the rate of change of the first motor's speed based on the first motor's speed;

[0097] Based on the rate of change of rotational speed, determine the change in the rotational speed of the first motor Δn per unit time;

[0098] according to Calculate the target speed compensation value;

[0099] Wherein, R1 represents the gear ratio of the first motor, R2 represents the target gear ratio of the second motor, and T represents the average time from the start of the second motor's speed adjustment to the moment the shift fork reaches the engagement position.

[0100] Optionally, after determining whether the driving state is an acceleration state, a deceleration state, or a steady speed state, it also includes;

[0101] If the driving state is determined to be a steady speed state, then the target speed compensation value is 0.

[0102] Optionally, the target speed compensation value can be locked as a fixed value when the second motor speed is adjusted.

[0103] This invention also provides a vehicle, including a dual-motor drive system and the aforementioned gear shifting and speed control device.

[0104] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for shifting and speed regulation control of a dual-motor drive system, characterized in that, The dual-motor drive system includes a first motor and a second motor, used to control the speed of the second motor to complete the gear shift when the first motor drives the vehicle and the second motor shifts gears. The gear shifting speed control method includes: The current driving status of the vehicle is determined based on the operating status of the first motor; Based on the driving state and the target gear of the second motor, determine the target speed compensation value of the second motor; Adjust the speed of the second motor according to the target speed compensation value so that the speed of the second motor matches the target gear. The step of determining the target speed compensation value of the second motor based on the driving state and the target gear of the second motor includes: Determine whether the driving state is an acceleration state, a deceleration state, or a steady speed state; If the driving state is determined to be an acceleration state or a deceleration state, then the target speed compensation value is calculated based on the speed of the first motor and the target gear. The method for calculating the target speed compensation value includes: Determine the rate of change of the first motor's speed based on the first motor's speed; Based on the speed change rate, determine the change in the speed of the first motor Δ per unit time. n ; according to Calculate the target speed compensation value; in, R 1 indicates the gear ratio of the first motor in gear. R 2 indicates the target gear ratio corresponding to the second motor. T This indicates the average time from the start of the second motor speed adjustment to when the shift fork push-engage sleeve reaches the tooth engagement position.

2. The shifting speed control method for a dual-motor drive system according to claim 1, characterized in that, Determining the current driving status of the vehicle based on the operating status of the first motor includes: The rotational speed of the first motor is acquired multiple times within a preset time period; The rate of change of the first motor speed is determined based on multiple speeds of the first motor. The current driving state of the vehicle is determined based on the rate of change of rotational speed.

3. The shifting speed control method for a dual-motor drive system according to claim 2, characterized in that, The driving states include acceleration, deceleration, and steady speed. Determining the vehicle's current driving state based on the rate of change of rotational speed includes: If the rate of change of rotational speed is greater than or equal to the first threshold M times within a preset time, the vehicle is determined to be in an acceleration state. If the rate of change of rotational speed is less than or equal to the second threshold N times within a preset time, the vehicle is determined to be in a deceleration state. If the rate of change of rotational speed is between the first threshold and the second threshold P times within a preset time, the vehicle is determined to be in a steady-speed state. Wherein, the first threshold is a positive value, the second threshold is a negative value, and M, N, and P are all integers greater than or equal to 1.

4. The shifting speed control method for a dual-motor drive system according to claim 3, characterized in that, The first threshold value is different when the first motor is in different gears, and the first threshold value is proportional to the speed ratio of the gear in which the first motor is in. The second threshold value varies depending on the gear position of the first motor. The second threshold value is inversely proportional to the speed ratio of the gear position of the first motor.

5. The shifting speed control method for a dual-motor drive system according to claim 1, characterized in that, After determining whether the driving state is an acceleration state, a deceleration state, or a steady speed state, the process also includes: If the driving state is determined to be a steady speed state, then the target speed compensation value is 0.

6. The shifting speed control method for a dual-motor drive system according to claim 1, characterized in that, The target speed compensation value is locked as a fixed value when the second motor adjusts its speed.

7. A gear shifting and speed regulation control device for a dual-motor drive system, characterized in that, A method for performing a shifting speed control device for a dual-motor drive system according to any one of claims 1 to 6, wherein the shifting speed control device comprises: The driving status determination module is used to determine the current driving status of the vehicle based on the operating status of the first motor. The compensation value determination module is used to determine the target speed compensation value of the second motor based on the driving state and the target gear of the second motor. The compensation module is used to adjust the speed of the second motor according to the target speed compensation value so that the speed of the second motor matches the target gear.

8. A vehicle, characterized in that, It includes a dual-motor drive system and the gear shifting speed control device as described in claim 7.

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