A vehicle drive mode control method, device, system, and storage medium

Abstract

This application discloses a vehicle drive mode control method, device, system, and storage medium. The method includes: monitoring the vehicle speed and required torque during vehicle operation; when the required torque meets the conditions for a single-axle drive mode, selecting the corresponding drive axle based on the vehicle speed to enter the single-axle drive mode; in the single-axle drive mode, when the required torque exceeds the intervention torque threshold corresponding to the current dominant axle, controlling the non-dominant axle to engage gears to provide power compensation, thereby controlling the vehicle to enter a dual-axle drive mode; in the dual-axle drive mode, when the required torque is lower than the exit torque threshold corresponding to the current dominant axle, controlling the non-dominant axle to disengage gears, thereby controlling the vehicle to return to the single-axle drive mode. The solution provided in this application eliminates the inherent parasitic losses caused by the non-drive axle idling in gear while ensuring overall drive efficiency.

Description

Technical Field

[0001] This application relates to the field of electric vehicle drive control technology, and in particular to a vehicle drive mode control method, device, system and storage medium. Background Technology

[0002] Multi-axle cooperative drive system refers to a drive method in which a vehicle uses two or more drive axles to drive the wheels in a coordinated manner. It is widely used in heavy-duty trucks, electric vehicles and special purpose vehicles to improve power performance, passability and driving stability.

[0003] Existing multi-axle cooperative drive solutions mainly focus on dynamic torque distribution strategies between axles to optimize energy economy. These methods, based on the efficiency characteristics of each drive motor, adjust the torque output ratio between the middle and rear axles in real time to achieve optimal overall system efficiency and thus realize economical driving of the entire vehicle. Summary of the Invention

[0004] This application provides a vehicle drive mode control method, device, system, and storage medium to further improve vehicle economy.

[0005] This application provides a vehicle drive mode control method, including: During vehicle operation, monitor vehicle speed and required torque; When the required torque meets the conditions of single-axle drive mode, the corresponding drive axle is selected based on the vehicle speed to enter single-axle drive mode. In single-axle drive mode, when the required torque exceeds the intervention torque threshold corresponding to the current dominant axle, the non-dominant axle is controlled to engage gears to provide power compensation in order to control the vehicle to enter dual-axle drive mode. In dual-axle drive mode, when the required torque is lower than the exit torque threshold corresponding to the current dominant axle, the non-dominant axle is disengaged to control the vehicle to return to single-axle drive mode. The disengagement is used to physically disconnect the non-dominant axle from the transmission path, eliminating the inherent parasitic losses caused by the non-drive axle spinning in gear.

[0006] The beneficial effects of this application are as follows: By judging the vehicle's operating conditions and required torque in real time, the redundant electric drive axle is actively controlled to disengage, thus physically decoupling its transmission system from the power source. This fundamentally eliminates the mechanical friction loss and gear churning loss generated by the axle under no-load conditions, directly reducing unnecessary driving resistance and effectively lowering the overall vehicle energy consumption. Furthermore, by automatically switching between single rear axle drive, single middle axle drive, and dual-axle combined drive modes under different driving conditions, the system can be ensured to always operate in the high-efficiency range under different conditions, thereby improving overall drive efficiency. Therefore, this application eliminates the inherent parasitic losses caused by the non-drive axle idling in gear while ensuring overall drive efficiency.

[0007] In one embodiment, when the middle axle is a single-gear transmission and the rear axle is a multi-gear transmission, the step of selecting the corresponding drive axle to enter single-axle drive mode based on the vehicle speed includes: When the vehicle speed is lower than the speed at which the rear axle shifts into first gear, the vehicle is controlled to use a single rear axle drive mode, and the rear axle gear is kept in first gear. When the vehicle speed is higher than the upshift point speed of the rear axle, and the gear ratio of the rear axle after upshifting is higher than the gear ratio of the middle axle, the vehicle is controlled to adopt a single rear axle drive mode, and the rear axle gear is controlled to upshift. When the vehicle speed is higher than the upshift point speed of the rear axle, and the gear ratio of the rear axle after upshifting is lower than the gear ratio of the middle axle, the vehicle is controlled to adopt a single middle axle drive mode.

[0008] In one embodiment, when the drive axle in the single-axle drive mode is the rear axle, controlling the non-dominant axle to engage gears to provide power compensation when the required torque exceeds the torque threshold corresponding to the current dominant axle includes: When the torque demanded by the driver exceeds the threshold for mid-axle intervention determined by the lower limit of the high-efficiency zone of the electric drive axle corresponding to the rear axle (MAP), the mid-axle intervenes to provide power.

[0009] In one embodiment, when the drive axle in the single-axle drive mode is the middle axle, the step of controlling the non-dominant axle to engage gears to provide power compensation when the required torque exceeds the torque threshold corresponding to the current dominant axle includes: When the required torque exceeds the rear axle intervention torque threshold determined based on the upper limit of the high-efficiency zone of the electric drive axle corresponding to the middle axle, the rear axle is controlled to engage gears to provide power compensation through the rear axle.

[0010] In one embodiment, the electric drive bridge efficiency MAP is determined as follows: Through bench tests, the comprehensive efficiency values ​​of the middle axle and rear axle electric drive system assemblies under different speed and output torque conditions were obtained. A complete electric drive bridge efficiency MAP is generated based on the overall efficiency. The MAP reflects the high-efficiency operating range of the entire system with the overall efficiency of the entire electric drive bridge assembly as the core basis. Based on the drawn electric drive bridge efficiency MAP, within its high-efficiency region, taking into account the rated torque capability of the motor and the distribution of the high-efficiency region, a basic threshold curve with motor speed as the abscissa and torque as the ordinate is determined. Based on the aforementioned basic threshold curve, a hysteresis interval is set.

[0011] The beneficial effects of this embodiment are as follows: by obtaining the comprehensive efficiency values ​​of the middle and rear axle electric drive system assemblies under different speed and output torque conditions through bench tests, and drawing a complete electric drive axle efficiency MAP based on this, it can accurately reflect the actual working performance of the entire system, and eliminate the limitations of relying solely on single motor efficiency optimization or fixed torque distribution strategies.

[0012] In one embodiment, setting the hysteresis interval includes: The torque threshold curve for rear axle intervention is shifted upward by a fixed value, and the torque threshold curve for rear axle withdrawal is shifted downward by the same fixed value.

[0013] The beneficial effects of this embodiment are: by setting a reasonable hysteresis interval, the stability of the system operation is ensured, the driving mode is prevented from oscillating frequently at the threshold boundary, and the smoothness and reliability of the system are improved.

[0014] In one embodiment, the method further includes: In dual-axle drive mode, the torque distribution ratio is dynamically adjusted according to the efficiency MAP of each axle to achieve the optimal efficiency of the overall drive system.

[0015] The beneficial effects of this embodiment are as follows: In dual-axle drive mode, the torque distribution ratio is dynamically adjusted according to the respective efficiency MAP of the two axles, so that the two axles can work in their respective high-efficiency range as much as possible, thereby achieving the optimal efficiency of the overall drive system, reducing energy loss in the transmission process, improving the energy utilization efficiency of the whole vehicle, and extending the vehicle's driving range.

[0016] This application also provides a vehicle drive mode control device for executing the vehicle drive mode control method described in any of the following embodiments, including: The monitoring module is used to monitor the vehicle speed and required torque during vehicle operation. The selection module is used to select the appropriate drive axle to enter single-axle drive mode based on the vehicle speed when the required torque meets the conditions of single-axle drive mode. The first control module is used to control the non-dominant axle to engage gears and provide power compensation when the required torque exceeds the intervention torque threshold corresponding to the current dominant axle in single-axle drive mode, so as to control the vehicle to enter dual-axle drive mode. The second control module is used to control the non-dominant axle to disengage and disengage when the required torque is lower than the exit torque threshold corresponding to the current dominant axle in the dual-axle drive mode, so as to control the vehicle to return to the single-axle drive mode. The disengagement and disengagement is used to physically disconnect the non-dominant axle from the transmission path and eliminate the inherent parasitic losses caused by the non-drive axle spinning in gear.

[0017] This application also provides a vehicle drive mode control system, including: At least one processor; and, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor to implement the vehicle drive mode control method described in any of the following embodiments.

[0018] This application also provides a computer-readable storage medium, which, when the instructions in the storage medium are executed by a processor corresponding to a vehicle drive mode control system, enables the vehicle drive mode control system to implement the vehicle drive mode control method described in any of the following embodiments.

[0019] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0020] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0021] The accompanying drawings are provided to further illustrate the present application and form part of the specification. They are used together with the embodiments of the present application to explain the application and do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart of a vehicle drive mode control method according to an embodiment of this application; Figure 2 This is a block diagram of a vehicle drive mode control device according to an embodiment of this application; Figure 3 This is a schematic diagram of the hardware structure of a vehicle drive module control system according to one embodiment of this application. Detailed Implementation

[0022] The preferred embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0023] Existing multi-axle cooperative drive solutions mainly focus on dynamic torque distribution strategies between axles to optimize energy economy. However, this solution has an inherent drawback: to achieve continuous torque distribution and adjustment, the middle and rear dual electric drive axles must always remain in gear during vehicle operation. This results in drag losses in the transmission system even if one electric drive axle does not need to output drive torque due to inherent factors such as mechanical friction and gear oil churning.

[0024] The applicant discovered in actual production and application that under many actual driving conditions (such as low-to-medium load cruising), the vehicle's drive requirements can be met by a single electric drive axle, which operates within its high-efficiency range without affecting efficiency. In this situation, the other electric drive axle, which is always engaged, cannot be de-engaged. In this case, its engagement becomes meaningless, only contributing to additional resistance losses, thus reducing the overall drive system efficiency, increasing unnecessary driving energy consumption, and hindering further improvements in vehicle economy. Therefore, how to eliminate the inherent parasitic losses caused by the non-drive axle idling in gear while ensuring efficiency, and further improve vehicle economy, is a pressing technical problem that needs to be solved.

[0025] In view of this, the applicant proposes a vehicle drive mode control method, as follows: Figure 1 This is a flowchart of a vehicle drive mode control method according to an embodiment of this application, such as... Figure 1 As shown, the method can be implemented as follows: S101-S104: In step S101, during vehicle operation, the vehicle speed and required torque are monitored. In step S102, when the required torque meets the conditions for single-axle drive mode, the corresponding drive axle is selected based on the vehicle speed to enter single-axle drive mode. In step S103, in single-axle drive mode, when the required torque exceeds the intervention torque threshold corresponding to the current dominant axle, the non-dominant axle is controlled to engage gears to provide power compensation, so as to control the vehicle to enter dual-axle drive mode. In step S104, in dual-axle drive mode, when the required torque is lower than the exit torque threshold corresponding to the current dominant axle, the non-dominant axle is controlled to disengage and exit, so as to control the vehicle to return to single-axle drive mode. The disengagement is used to physically disconnect the non-dominant axle from the transmission path and eliminate the inherent parasitic losses caused by the non-drive axle idling in gear.

[0026] In this application, the vehicle speed and required torque are monitored during vehicle operation. The purpose of this step is to acquire key state parameters of the vehicle in real time, providing a basis for subsequent drive mode switching and torque distribution. Specifically, the vehicle speed and required torque can be monitored by installing speed sensors, required torque sensors, and motor speed sensors on key parts of the vehicle.

[0027] When the required torque meets the conditions of single-axle drive mode, the corresponding drive axle is selected based on the vehicle speed to enter single-axle drive mode. Specifically, when the middle axle is a single-gear transmission and the rear axle is a multi-gear transmission, the step of selecting the corresponding drive axle to enter the single-axle drive mode based on the vehicle speed includes: when the vehicle speed is lower than the upshift point speed of the rear axle in first gear, controlling the vehicle to adopt a single rear axle drive mode and keeping the rear axle in first gear; when the vehicle speed is higher than the upshift point speed of the rear axle in the current gear, and the gear ratio of the rear axle after upshifting is higher than the gear ratio of the middle axle, controlling the vehicle to adopt a single rear axle drive mode and controlling the rear axle to upshift; when the vehicle speed is higher than the upshift point speed of the rear axle in the current gear, and the gear ratio of the rear axle after upshifting is lower than the gear ratio of the middle axle, controlling the vehicle to adopt a single middle axle drive mode.

[0028] For example, when the middle axle is a single-gear transmission and the rear axle is a multi-gear transmission, the step of selecting the corresponding drive axle to enter single-axle drive mode based on the vehicle speed includes: when the vehicle speed is lower than the upshift point speed of the rear axle's first gear, controlling the vehicle to adopt a single rear axle drive mode and keeping the rear axle gear in first gear; when the vehicle speed is higher than the upshift point speed of the rear axle's first gear and the rear axle's second gear ratio is higher than the middle axle's gear ratio, controlling the vehicle to adopt a single rear axle drive mode and upshifting the rear axle to second gear; when the vehicle speed is higher than the upshift point speed of the rear axle's first gear and the rear axle's second gear ratio is lower than the middle axle's gear ratio, controlling the vehicle to adopt a single middle axle drive mode; when the vehicle speed is higher than... When the vehicle speed reaches the second gear upshift point on the rear axle, and the third gear ratio on the rear axle is higher than the gear ratio on the middle axle, the vehicle is controlled to use a single rear axle drive mode, and the rear axle gear is shifted to third gear. When the vehicle speed is higher than the second gear upshift point on the rear axle, and the third gear ratio on the rear axle is lower than the gear ratio on the middle axle, the vehicle is controlled to use a single middle axle drive mode. When the vehicle speed is higher than the third gear upshift point on the rear axle, and the fourth gear ratio on the rear axle is higher than the gear ratio on the middle axle, the vehicle is controlled to use a single rear axle drive mode, and the rear axle gear is shifted to fourth gear. When the vehicle speed is higher than the third gear upshift point on the rear axle, and the fourth gear ratio on the rear axle is lower than the gear ratio on the middle axle, the vehicle is controlled to use a single middle axle drive mode.

[0029] In single-axle drive mode, when the required torque exceeds the intervention torque threshold corresponding to the current dominant axle, the non-dominant axle is engaged to provide power compensation, thereby controlling the vehicle to enter dual-axle drive mode. Specifically, when the drive axle in single-axle drive mode is the rear axle, if the driver's required torque exceeds the intervention torque threshold of the middle axle determined based on the lower limit of the high-efficiency zone of the electric drive axle efficiency MAP corresponding to the rear axle, the middle axle intervenes to provide power. When the drive axle in single-axle drive mode is the middle axle, if the required torque exceeds the intervention torque threshold of the rear axle determined based on the upper limit of the high-efficiency zone of the electric drive axle efficiency MAP corresponding to the middle axle, the rear axle is engaged to provide power compensation.

[0030] The electric drive bridge efficiency MAP is determined according to the following method: Through bench tests, the comprehensive efficiency values ​​of the middle and rear axle electric drive system assemblies under different speeds and output torques were obtained. Based on the comprehensive efficiency, a complete electric drive axle efficiency MAP was generated. The MAP reflects the high-efficiency operating range of the entire system, with the comprehensive efficiency of the entire electric drive axle assembly as the core criterion. Based on the drawn electric drive axle efficiency MAP, within its high-efficiency range, considering the rated torque capability of the motor and the distribution of the high-efficiency range, a basic threshold curve was determined with motor speed as the abscissa and torque as the ordinate. Based on the basic threshold curve, a hysteresis interval was set.

[0031] The setting of the hysteresis interval includes: shifting upward by a fixed value as the torque threshold curve for rear axle intervention, and shifting downward by the same fixed value as the torque threshold curve for rear axle withdrawal.

[0032] In dual-axle drive mode, when the required torque is lower than the exit torque threshold corresponding to the current dominant axle, the non-dominant axle is disengaged to return the vehicle to single-axle drive mode. This disengagement physically removes the non-dominant axle from the transmission path, eliminating the inherent parasitic losses caused by the non-drive axle idling in gear. Furthermore, in dual-axle drive mode, the torque distribution ratio can be dynamically adjusted based on the respective efficiency map (MAP) of each axle to achieve optimal efficiency for the overall drive system.

[0033] The beneficial effects of this application are as follows: By judging the vehicle's operating conditions and required torque in real time, the redundant electric drive axle is actively controlled to disengage, thus physically decoupling its transmission system from the power source. This fundamentally eliminates the mechanical friction loss and gear churning loss generated by the axle under no-load conditions, directly reducing unnecessary driving resistance and effectively lowering the overall vehicle energy consumption. Furthermore, by automatically switching between single rear axle drive, single middle axle drive, and dual-axle combined drive modes under different driving conditions, the system can be ensured to always operate in the high-efficiency range under different conditions, thereby improving overall drive efficiency. Therefore, this application eliminates the inherent parasitic losses caused by the non-drive axle idling in gear while ensuring overall drive efficiency.

[0034] In one embodiment, when the middle axle is a single-gear transmission and the rear axle is a multi-gear transmission, the step S102 above, which selects the corresponding drive axle to enter the single-axle drive mode based on the vehicle speed, can be implemented as the following steps A1-A3: In step A1, when the vehicle speed is lower than the speed at which the rear axle shifts into first gear, the vehicle is controlled to adopt a single rear axle drive mode, and the rear axle gear is controlled to remain in first gear. In step A2, when the vehicle speed is higher than the upshift point speed of the rear axle and the gear ratio after the rear axle upshifts is higher than the gear ratio of the middle axle, the vehicle is controlled to adopt a single rear axle drive mode, and the rear axle gear is controlled to upshift. In step A3, when the vehicle speed is higher than the upshift point speed of the rear axle and the gear ratio after the rear axle upshifts is lower than the gear ratio of the middle axle, the vehicle is controlled to adopt a single middle axle drive mode.

[0035] For example, when the vehicle speed is below the re-shift point speed of the rear axle's first gear, the vehicle is controlled to use a single rear axle drive mode, and the rear axle gear is kept in first gear; when the vehicle speed is above the re-shift point speed of the rear axle's first gear, and the rear axle's second gear ratio is higher than the middle axle gear ratio, the vehicle is controlled to use a single rear axle drive mode, and the rear axle gear is shifted to second gear; when the vehicle speed is above the re-shift point speed of the rear axle's first gear, and the rear axle's second gear ratio is lower than the middle axle gear ratio, the vehicle is controlled to use a single middle axle drive mode; when the vehicle speed is above the re-shift point speed of the rear axle's second gear, and the rear axle's third gear ratio is higher than the middle axle gear ratio... When the speed ratio is set, the vehicle is controlled to use a single rear axle drive mode, and the rear axle gear is shifted to third gear; when the vehicle speed is higher than the second gear shift point speed of the rear axle, and the third gear ratio of the rear axle is lower than the gear ratio of the middle axle, the vehicle is controlled to use a single middle axle drive mode; when the vehicle speed is higher than the third gear shift point speed of the rear axle, and the fourth gear ratio of the rear axle is higher than the gear ratio of the middle axle, the vehicle is controlled to use a single rear axle drive mode, and the rear axle gear is shifted to fourth gear; when the vehicle speed is higher than the third gear shift point speed of the rear axle, and the fourth gear ratio of the rear axle is lower than the gear ratio of the middle axle, the vehicle is controlled to use a single middle axle drive mode.

[0036] This embodiment describes the scenario where the middle axle has a single-gear transmission and the rear axle has a multi-gear transmission. However, when both the middle and rear axles have multi-gear transmissions, the drive mode switching logic becomes more complex and nuanced. The system needs to comprehensively consider multiple factors such as vehicle speed, the current gear ratio of each axle, and the required torque to achieve optimal drive mode switching.

[0037] First, the system determines which axle should be used as the primary drive axle based on the current vehicle speed and the upshift speed of each axle. Within each gear range, the system compares the gear ratios of the middle and rear axles and selects the axle with the larger gear ratio as the primary drive axle to ensure optimal power transmission efficiency.

[0038] When changes in vehicle speed cause gear shifting, the system dynamically adjusts the selection of the drive axle. For example, when the vehicle speed exceeds the upshift point of a certain gear, the system will upshift that axle and then re-compare the gear ratios of the middle and rear axles to determine whether it is necessary to switch the dominant drive axle.

[0039] In dual-axle drive mode, the system dynamically adjusts the engagement and disengagement timing of the drive axles based on changes in required torque. When the required torque exceeds the engagement torque threshold of the dominant axle, the non-dominant axle engages to provide power compensation; when the required torque drops below the disengagement torque threshold, the non-dominant axle disengages, thus switching the drive mode.

[0040] The entire switching process requires real-time monitoring of vehicle status parameters to ensure optimal power distribution and energy efficiency control under various operating conditions.

[0041] It should be noted that if the average duration of rear axle drive is greater than that of mid-axle drive during daily use, mid-axle drive should be selected even if the gear ratios of the corresponding gears of the mid-axle and rear axle are the same, in order to reduce the wear and tear on the components of the rear axle.

[0042] In one embodiment, when the drive axle in the single-axle drive mode is the rear axle, the step S103 above, where the required torque exceeds the torque threshold corresponding to the current dominant axle, involves controlling the non-dominant axle to engage gears to provide power compensation, including the following steps: When the torque demanded by the driver exceeds the threshold for mid-axle intervention determined by the lower limit of the high-efficiency zone of the electric drive axle corresponding to the rear axle (MAP), the mid-axle intervenes to provide power.

[0043] In one embodiment, when the drive axle in the single-axle drive mode is the middle axle, the step S103 above, where the required torque exceeds the torque threshold corresponding to the current dominant axle, involves controlling the non-dominant axle to engage gears to provide power compensation, including the following steps: When the required torque exceeds the rear axle intervention torque threshold determined based on the upper limit of the high-efficiency zone of the electric drive axle corresponding to the middle axle, the rear axle is controlled to engage gears to provide power compensation through the rear axle.

[0044] In one embodiment, the electric drive bridge efficiency MAP is determined according to the following steps B1-B4: In step B1 above, the comprehensive efficiency values ​​of the middle axle and rear axle electric drive system assemblies under different speed and output torque conditions are obtained through bench tests. In step B2 above, a complete electric drive bridge efficiency MAP is generated based on the overall efficiency. The MAP reflects the high-efficiency operating range of the entire system based on the overall efficiency of the entire electric drive bridge assembly. In step B3 above, based on the plotted electric drive bridge efficiency MAP, within its high-efficiency range, taking into account the rated torque capability of the motor and the distribution of the high-efficiency range, a basic threshold curve with motor speed as the abscissa and torque as the ordinate is determined. In step B4 above, the hysteresis interval is set based on the basic threshold curve.

[0045] In this embodiment, a comprehensive performance test is conducted on the middle and rear axle electric drive system assemblies through precise bench tests. The overall efficiency value under different speed and torque combinations is recorded to ensure that the drawn electric drive axle efficiency MAP can accurately reflect the actual working performance of the entire system, thus eliminating the limitations of relying solely on single motor efficiency optimization or fixed torque distribution strategies.

[0046] In the step of determining the basic threshold curve, the relationship between the rated torque capacity of the motor and the distribution of the high-efficiency zone is analyzed in combination with the actual working characteristics of the middle and rear axle electric drive systems. This ensures that the determined basic threshold curve can make full use of the system's high-efficiency working zone and adapt to the changes in torque demand under different driving conditions.

[0047] In the step of setting the hysteresis range, the selected offset setpoint is adjusted and optimized according to the actual vehicle performance and driving experience to ensure that the hysteresis range width can effectively avoid frequent switching of driving modes and ensure the system's rapid response capability under different torque requirements.

[0048] The beneficial effects of this embodiment are as follows: by obtaining the comprehensive efficiency values ​​of the middle and rear axle electric drive system assemblies under different speed and output torque conditions through bench tests, and drawing a complete electric drive axle efficiency MAP based on this, it can accurately reflect the actual working performance of the entire system, and eliminate the limitations of relying solely on single motor efficiency optimization or fixed torque distribution strategies.

[0049] In one embodiment, setting the hysteresis interval can be implemented by the following steps: The torque threshold curve for rear axle intervention is shifted upward by a fixed value, and the torque threshold curve for rear axle withdrawal is shifted downward by the same fixed value.

[0050] The beneficial effects of this embodiment are: by setting a reasonable hysteresis interval, the stability of the system operation is ensured, the driving mode is prevented from oscillating frequently at the threshold boundary, and the smoothness and reliability of the system are improved.

[0051] The solution provided in this application is applicable to configurations where the middle axle is driven by dual motors at the wheel sides. It utilizes the strong independent driving capability of the middle axle to achieve efficient driving of a single middle axle in the medium-to-high speed range.

[0052] In one embodiment, the method may also be implemented as follows: In dual-axle drive mode, the torque distribution ratio is dynamically adjusted according to the efficiency MAP of each axle to achieve the optimal efficiency of the overall drive system.

[0053] In this embodiment, under dual-axle drive mode, the middle and rear axle electric drive systems exhibit different efficiency performances at different speeds and torque conditions due to differences in motor characteristics, reducer structures, and transmission components. The overall efficiency values ​​of the middle and rear axle electric drive system assemblies under different speeds and output torque conditions are pre-acquired, and their respective efficiency maps are plotted. During vehicle operation, the speed of both axles and the vehicle's required torque are monitored in real time. Based on this real-time data and the efficiency maps of the two axles, the torque distribution ratio between the two axles is dynamically adjusted, ensuring that both axles operate within their respective high-efficiency zones, thereby achieving optimal efficiency for the overall drive system.

[0054] For example, during vehicle operation, sensors collect real-time information on the motor speeds of both axles and the vehicle's required torque. The sensors transmit the collected signals to the Vehicle Control Unit (VCU). Based on the real-time motor speeds of the two axles, the VCU locates the corresponding speed coordinates in their respective efficiency maps. Then, using these coordinates as a reference, it searches the efficiency maps for the torque distribution range that allows both axles to operate in their high-efficiency zones at that speed. For instance, if the high-efficiency torque range for the middle axle at the current speed is 50-150 Nm, and for the rear axle it's 30-120 Nm, combined with the vehicle's required torque, a specific algorithm calculates the optimal torque distribution ratio for both axles. The VCU sends the calculated torque distribution command to the motor controllers of the middle and rear axles. The motor controllers adjust the motor output torque according to the command, achieving dynamic torque distribution between the two axles.

[0055] This allows both axles to operate in their high-efficiency range, reducing energy loss during transmission and thus improving the overall energy efficiency of the vehicle, extending its driving range—a crucial feature for electric vehicles. Furthermore, dynamically adjusting the torque distribution ratio prevents one axle from malfunctioning due to prolonged inefficient or overloaded conditions, improving the stability and reliability of the entire drive system. A well-balanced torque distribution allows the vehicle to achieve better power performance during acceleration and hill climbing, while ensuring smooth driving and enhancing the driving experience.

[0056] For example, the optimal torque distribution ratio for a dual-axle bridge can be calculated using a specific algorithm in the following way: Method 1, Iso-efficiency curve method: Plot iso-efficiency curves on the efficiency MAP of the dual-axle bridge, and determine the torque distribution ratio of the dual-axle bridge by finding the intersection point or the optimal combination point of the two iso-efficiency curves to maximize the overall efficiency.

[0057] Method 2: Optimization Algorithms: Such as genetic algorithms and particle swarm optimization algorithms, the torque distribution ratio of the dual-bridge is used as the optimization variable, and the efficiency of the overall drive system is maximized as the objective function. Optimization calculations are performed under certain constraints to obtain the optimal torque distribution ratio.

[0058] The beneficial effects of this embodiment are as follows: In dual-axle drive mode, the torque distribution ratio is dynamically adjusted according to the respective efficiency MAP of the two axles, so that the two axles can work in their respective high-efficiency range as much as possible, thereby achieving the optimal efficiency of the overall drive system, reducing energy loss in the transmission process, improving the energy utilization efficiency of the whole vehicle, and extending the vehicle's driving range.

[0059] This application proactively controls the redundant electric drive axle to disengage from its gears by real-time assessment of vehicle operating conditions and required torque, physically decoupling its transmission system from the power source. This fundamentally eliminates mechanical friction losses and gear churning losses generated by the axle under no-load conditions, directly reducing unnecessary driving resistance and effectively lowering overall vehicle energy consumption. Furthermore, based on the intervention and disengagement thresholds set within the high-efficiency zone of the electric drive axle's efficiency MAP, it ensures that the system is always guided to operate within the optimal or near-optimal efficiency range, regardless of whether it's single-axle or dual-axle drive, maintaining the vehicle's drive efficiency at a consistently high level and achieving optimized system performance under all operating conditions. The combined effect of these two advantages ultimately results in a substantial improvement in the vehicle's energy utilization efficiency—consuming less electrical energy while providing the same driving power—significantly increasing the driving range of pure electric heavy-duty trucks, reducing operating costs, and demonstrating clear economic benefits.

[0060] Figure 2 This is a block diagram of a vehicle drive mode control device according to an embodiment of this application, such as... Figure 2 As shown, it includes: The monitoring module 201 is used to monitor the vehicle speed and required torque during vehicle operation. The selection module 202 is used to select the corresponding drive axle to enter the single-axle drive mode based on the vehicle speed when the required torque meets the conditions of the single-axle drive mode. The first control module 203 is used to control the non-dominant axle to engage gears and provide power compensation when the required torque exceeds the intervention torque threshold corresponding to the current dominant axle in single-axle drive mode, so as to control the vehicle to enter dual-axle drive mode. The second control module 204 is used to control the non-dominant axle to disengage and disengage when the required torque is lower than the exit torque threshold corresponding to the current dominant axle in the dual-axle drive mode, so as to control the vehicle to return to the single-axle drive mode. The disengagement and disengagement is used to physically disconnect the non-dominant axle from the transmission path and eliminate the inherent parasitic losses caused by the non-drive axle spinning in gear.

[0061] Figure 3 This is a schematic diagram of the hardware structure of a vehicle drive module control system according to one embodiment of this application, as shown below. Figure 3 As shown, the vehicle drive module control system includes: At least one processor 320; and, Memory 304 communicatively connected to the at least one processor 320; wherein, The memory 304 stores instructions that can be executed by the at least one processor 320 to implement the vehicle drive module control method described in any of the above embodiments.

[0062] Reference Figure 3 The vehicle drive module control system 300 may include one or more of the following components: processing component 302, memory 304, power supply component 306, input / output (I / O) interface 308, sensor component 310, and communication component 312.

[0063] Processing component 302 typically controls the overall operation of the vehicle drive module control system 300. Processing component 302 may include one or more processors 320 to execute instructions to complete all or part of the steps of the methods described above. Furthermore, processing component 302 may include one or more modules to facilitate interaction between processing component 302 and other components. The processor 320 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0064] Memory 304 is configured to store various types of data to support the operation of the vehicle drive module control system 300. Examples of this data include instructions for any application or method operating on the vehicle drive module control system 300. Memory 304 can be an internal storage unit of the terminal device, such as a hard disk or memory of the terminal device. Memory 304 can also be an external storage device of the terminal device, such as a plug-in hard disk equipped on the terminal device. Memory 304 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. Memory 304 is used to store programs and data required by this application. Memory 304 can also be used to temporarily store data that has been output or will be output.

[0065] Power supply assembly 306 provides power to various components of the vehicle drive module control system 300. Power supply assembly 306 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power to the vehicle drive module control system 300.

[0066] I / O interface 308 provides an interface between processing component 302 and peripheral interface modules, such as keyboards, click wheels, buttons, etc.

[0067] The sensor assembly 310 includes one or more sensors for providing status assessments of various aspects of the vehicle drive module control system 300. Additionally, the sensor assembly 310 can detect the on / off state of the vehicle drive module control system 300, the relative positioning of components, and the operational status of the vehicle drive module control system 300 or a component of the vehicle drive module control system 300. In some embodiments, the sensor assembly 310 may include an accelerometer, a gyroscope, a magnetometer, a pressure sensor, or a temperature sensor, etc.

[0068] Communication component 312 is configured to enable vehicle drive module control system 300 to provide wired or wireless communication capabilities with other devices and cloud platforms. Vehicle drive module control system 300 can access wireless networks based on communication standards, such as WiFi, 2G, or 3G, or combinations thereof. In one exemplary embodiment, communication component 316 receives broadcast signals or broadcast-related information from an external broadcast management system via a broadcast channel. In one exemplary embodiment, communication component 316 also includes a near-field communication (NFC) module to facilitate short-range communication. For example, the NFC module may be implemented based on radio frequency identification (RFID) technology, Infrared Data Association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology, and other technologies.

[0069] In an exemplary embodiment, the vehicle drive module control system 300 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to perform the vehicle drive module control method described in any of the above embodiments.

[0070] This application also provides a computer-readable storage medium, which, when the instructions in the storage medium are executed by a processor corresponding to the vehicle drive module control system, enables the vehicle drive module control system to implement the vehicle drive module control method described in any of the above embodiments.

[0071] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0072] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1A device that provides the functions specified in one or more boxes.

[0073] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0074] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0075] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A vehicle drive mode control method, characterized in that, include: During vehicle operation, monitor vehicle speed and required torque; When the required torque meets the conditions of single-axle drive mode, the corresponding drive axle is selected based on the vehicle speed to enter single-axle drive mode. In single-axle drive mode, when the required torque exceeds the intervention torque threshold corresponding to the current dominant axle, the non-dominant axle is controlled to engage gears to provide power compensation in order to control the vehicle to enter dual-axle drive mode. In dual-axle drive mode, when the required torque is lower than the exit torque threshold corresponding to the current dominant axle, the non-dominant axle is disengaged to control the vehicle to return to single-axle drive mode. The disengagement is used to physically disconnect the non-dominant axle from the transmission path, eliminating the inherent parasitic losses caused by the non-drive axle spinning in gear.

2. The method as described in claim 1, characterized in that, When the middle axle is a single-speed gearbox and the rear axle is a multi-speed gearbox, the step of selecting the corresponding drive axle to enter single-axle drive mode based on the vehicle speed includes: When the vehicle speed is lower than the speed at which the rear axle shifts into first gear, the vehicle is controlled to use a single rear axle drive mode, and the rear axle gear is kept in first gear. When the vehicle speed is higher than the upshift point speed of the rear axle, and the gear ratio of the rear axle after upshifting is higher than the gear ratio of the middle axle, the vehicle is controlled to adopt a single rear axle drive mode, and the rear axle gear is controlled to upshift. When the vehicle speed is higher than the upshift point speed of the rear axle, and the gear ratio of the rear axle after upshifting is lower than the gear ratio of the middle axle, the vehicle is controlled to adopt a single middle axle drive mode.

3. The method as described in claim 1, characterized in that, When the drive axle in single-axle drive mode is the rear axle, the step of controlling the non-dominant axle to engage gears to provide power compensation when the required torque exceeds the torque threshold corresponding to the current dominant axle includes: When the torque demanded by the driver exceeds the threshold for mid-axle intervention determined by the lower limit of the high-efficiency zone of the electric drive axle corresponding to the rear axle (MAP), the mid-axle intervenes to provide power.

4. The method as described in claim 1, characterized in that, When the drive axle in single-axle drive mode is the middle axle, the step of controlling the non-dominant axle to engage gears to provide power compensation when the required torque exceeds the torque threshold corresponding to the current dominant axle includes: When the required torque exceeds the rear axle intervention torque threshold determined based on the upper limit of the high-efficiency zone of the electric drive axle corresponding to the middle axle, the rear axle is controlled to engage gears to provide power compensation through the rear axle.

5. The method as described in claim 1, characterized in that, The electric drive bridge efficiency MAP is determined according to the following method: Through bench tests, the comprehensive efficiency values ​​of the middle axle and rear axle electric drive system assemblies under different speed and output torque conditions were obtained. A complete electric drive bridge efficiency MAP is generated based on the overall efficiency. The MAP reflects the high-efficiency operating range of the entire system with the overall efficiency of the entire electric drive bridge assembly as the core basis. Based on the drawn electric drive bridge efficiency MAP, within its high-efficiency region, taking into account the rated torque capability of the motor and the distribution of the high-efficiency region, a basic threshold curve with motor speed as the abscissa and torque as the ordinate is determined. Based on the aforementioned basic threshold curve, a hysteresis interval is set.

6. The method as described in claim 5, characterized in that, The setting of the hysteresis interval includes: The torque threshold curve for rear axle intervention is shifted upward by a fixed value, and the torque threshold curve for rear axle withdrawal is shifted downward by the same fixed value.

7. The method as described in claim 1, characterized in that, The method further includes: In dual-axle drive mode, the torque distribution ratio is dynamically adjusted according to the efficiency MAP of each axle to achieve the optimal efficiency of the overall drive system.

8. A vehicle drive mode control device, used to execute the vehicle drive mode control method as described in any one of claims 1-7, characterized in that, include: The monitoring module is used to monitor the vehicle speed and required torque during vehicle operation. The selection module is used to select the appropriate drive axle to enter single-axle drive mode based on the vehicle speed when the required torque meets the conditions of single-axle drive mode. The first control module is used to control the non-dominant axle to engage gears and provide power compensation when the required torque exceeds the intervention torque threshold corresponding to the current dominant axle in single-axle drive mode, so as to control the vehicle to enter dual-axle drive mode. The second control module is used to control the non-dominant axle to disengage and disengage when the required torque is lower than the exit torque threshold corresponding to the current dominant axle in the dual-axle drive mode, so as to control the vehicle to return to the single-axle drive mode. The disengagement and disengagement is used to physically disconnect the non-dominant axle from the transmission path and eliminate the inherent parasitic losses caused by the non-drive axle spinning in gear.

9. A vehicle drive mode control system, characterized in that, include: At least one processor; as well as, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to implement the vehicle drive mode control method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, When the instructions in the storage medium are executed by the processor corresponding to the vehicle drive mode control system, the vehicle drive mode control system is able to implement the vehicle drive mode control method as described in any one of claims 1-7.

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