Heavy commercial vehicle electric drive system driving mode switching cooperative control method

Abstract

The application discloses a kind of heavy commercial vehicle electric drive system drive mode switching collaborative control method, specifically related to collaborative control field, including S1, real-time acquisition multidimensional operation data, provide data basis;S2, based on the multidimensional operation data of acquisition, through specific formula calculation vehicle real-time driving demand degree, as the core decision index of mode switching;S4, when mode switching, through collaborative strategy, realize the smooth cooperation of motor and transmission;The application obtains the accurate decision basis of driving mode through multidimensional parameter acquisition and the dynamic calculation of driving demand degree, solves the problem that switching decision only relies on single or a small number of parameters, leading to switching opportunity lag or misjudgment, improves the power response speed of vehicle under complex working conditions such as acceleration, climbing, and can adaptively match low, medium and high load scenarios.

Description

Technical Field

[0001] This invention relates to the field of collaborative control technology, and more specifically, to a collaborative control method for switching drive operating modes of an electric drive system for heavy-duty commercial vehicles. Background Technology

[0002] Currently, electric drive systems for heavy-duty commercial vehicles mostly adopt a drive configuration combining multiple motors and multiple gears, adapting to complex operating conditions by switching between different drive modes. In existing technologies, drive mode switching is mainly based on basic parameters such as vehicle speed and load, triggering single-motor / dual-motor drive and high / low gear switching through preset thresholds to achieve an initial match between power output and operating condition requirements.

[0003] The advantage of existing drive mode switching technology is that it can basically meet the power and energy consumption requirements of vehicles under normal road conditions, and improves the adaptability of vehicles through the coordinated work of motor and transmission. However, there are obvious shortcomings: First, the switching decision relies on only one or a few parameters, without considering dynamic factors such as motor efficiency, battery status, and road condition change rate, resulting in delayed or misjudged switching timing, such as power response delay under rapid acceleration conditions; Second, the coordinated control precision of motor torque and gear shifting during mode switching is insufficient, which can easily generate impact loads, affecting driving comfort and aggravating wear on transmission components; Third, no linkage mechanism between drive mode and energy recovery has been established, resulting in low energy recovery efficiency under deceleration or downhill conditions.

[0004] To address the problems of one-sided decision-making in drive mode switching, insufficient precision in coordinated control, and poor energy recovery linkage in existing technologies, this invention proposes a coordinated control method for drive mode switching in heavy-duty commercial vehicle electric drive systems. Through multi-dimensional parameter acquisition, dynamic decision model construction, and refined coordinated control strategies, it achieves precise switching and efficient coordination of drive modes, thereby improving vehicle power, economy, and component reliability. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, the present invention provides a method for coordinated control of drive working mode switching of heavy commercial vehicle electric drive system, which solves the problems mentioned in the background art through the following scheme.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for coordinated control of drive mode switching in a heavy-duty commercial vehicle electric drive system, comprising: S1. Real-time collection of multi-dimensional operational data to provide a data foundation; S2. Based on the collected multi-dimensional operational data, the real-time driving demand of the vehicle is calculated using a specific formula, which serves as the core decision indicator for mode switching. S3. Divide the working conditions according to the drive demand and motor efficiency characteristics, match the corresponding drive mode, and set an adaptive mode switching lag compensation mechanism to avoid frequent switching. S4. During mode switching, a coordination strategy is used to achieve smooth operation between the motor and the transmission. S5. Real-time monitoring of the impact during the switching process, and closed-loop adjustment by correcting the torque transition coefficient to control the impact within the set range.

[0007] Preferably, the multi-dimensional operating data includes motor parameters, battery parameters, vehicle status parameters, and environmental parameters; the motor parameters specifically include the speed of the front electric drive axle main drive motor. Output torque ,efficiency Rear electric drive axle drive motor speed Output torque ,efficiency Front electric drive axle auxiliary drive motor speed Output torque ,efficiency The battery parameters specifically include the current SOC value S and the output power. The vehicle state parameters specifically include driving speed v, acceleration a, load mass m, and gradient. The environmental parameters include the road surface adhesion coefficient. .

[0008] Preferably, the driving demand degree Where g represents the acceleration due to gravity. The value represents the air resistance coefficient, and A represents the vehicle's frontal area. This indicates the battery's maximum output power.

[0009] Preferably, the operating conditions are classified as follows: when D < 0.3, it is determined to be a low-load operating condition; when 0.3 ≤ D < 0.6, it is determined to be a medium-load operating condition; and when D ≥ 0.6, it is determined to be a high-load operating condition.

[0010] Preferably, the driving mode is as follows: under low load conditions, the rear electric drive axle single motor + second gear mode is activated. At this time, the front electric drive axle main drive motor and auxiliary drive motor are stopped, and the rear electric drive axle drive motor operates at high efficiency. Operating within a range of ≥85%; under medium load conditions, activating the front electric drive axle main drive motor + rear electric drive axle drive motor + three-speed mode, with the front electric drive axle main drive motor efficiency... ≥88%, efficiency of the rear electric drive axle drive motor ≥85%; Under high load conditions, the three-motor coordinated + first gear mode is activated, and the auxiliary drive motor of the front electric drive axle is engaged through a synchronizer. The efficiency of all three motors must meet the following requirements. , , ≥80%; The adaptive mode: when D fluctuates within the threshold range, maintain the current mode for 1.5s before switching.

[0011] Preferably, the coordinated strategy includes torque transition control, gear shift coordination, and energy recovery linkage.

[0012] Preferably, the torque transition control is as follows: when switching from a low-load mode to a medium-load mode, the output torque of the main drive motor of the front electric drive axle is... Dynamically incremented according to the following formula: ,in The target torque is represented by k, the torque transition coefficient is represented by t, and the transition time is represented by t; simultaneously, the torque of the rear electric drive axle drive motor is calculated according to... Decrease gradually to maintain a smooth transition of total torque, among which This indicates the initial torque.

[0013] Preferably, the gear shifting coordination is as follows: when gear shifting is required, synchronization is first achieved through motor speed adjustment, with the synchronization speed difference... ,in Indicates the current motor speed. Indicates the target gear speed, when Once the conditions are met, the synchronizer engages to complete the gear shift. During the gear shift, the motor torque must be reduced to less than 30% of the rated torque.

[0014] Preferably, the energy recovery linkage is as follows: when the vehicle is in a deceleration condition (a < 0 and D < 0.2), it automatically switches to energy recovery mode, and the front and rear electric drive axle motors switch to generator mode to recover torque. The recovered electrical energy is directly stored in the battery, and the braking intensity must be ≤0.3g during the recovery process to avoid wheel lock-up.

[0015] Preferably, the impact force ,in This indicates the gear ratio of the current gear, r represents the wheel rolling radius, and f represents the rolling resistance coefficient; when the impact exceeds the impact threshold, the torque transition coefficient is corrected. Continue until the impact threshold is lowered to ensure a smooth switching process.

[0016] The technical effects and advantages of this invention are as follows: 1. This invention obtains accurate decision-making basis for driving mode by collecting multi-dimensional parameters and dynamically calculating driving demand. It solves the problem that switching decisions rely on only a single or a few parameters, which leads to delayed or misjudged switching timing. It improves the power response speed of the vehicle under complex working conditions such as acceleration and climbing, and can adaptively match low, medium and high load scenarios. 2. This invention achieves a smooth power transition during mode switching by using torque transition control, gear shift coordination, and closed-loop feedback adjustment. It solves the problem of insufficient control precision of motor torque and gear shift coordination, which easily generates impact loads and aggravates the wear of transmission components. It achieves impact control, reduces the wear rate of transmission components, and improves driving comfort. 3. By establishing a linkage mechanism between the driving mode and energy recovery, this invention achieves efficient energy recovery under deceleration / downhill conditions, solving the problem of low energy recovery efficiency when the linkage mechanism between the driving mode and energy recovery is not established, thus improving energy recovery efficiency and extending the vehicle's driving range. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, 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 are within the scope of protection of the present invention.

[0019] As attached Figure 1 The method for coordinated control of drive mode switching in an electric drive system for heavy-duty commercial vehicles, as shown, includes: S1. Real-time collection of multi-dimensional operational data to provide a data foundation; Specifically, it should be noted that the multi-dimensional operating data includes motor parameters, battery parameters, vehicle status parameters, and environmental parameters; the motor parameters specifically include the speed of the front electric drive axle main drive motor. Output torque ,efficiency Rear electric drive axle drive motor speed Output torque ,efficiency Front electric drive axle auxiliary drive motor speed Output torque ,efficiency The battery parameters specifically include the current SOC value S and the output power. The vehicle state parameters specifically include driving speed v, acceleration a, load mass m, and gradient. The environmental parameters include the road surface adhesion coefficient. ; S2. Based on the collected multi-dimensional operational data, the real-time driving demand of the vehicle is calculated using a specific formula, which serves as the core decision indicator for mode switching. Specifically, it should be noted that the aforementioned driving demand degree Where g represents the acceleration due to gravity. The value represents the air resistance coefficient, and A represents the vehicle's frontal area. Indicates the battery's maximum output power; S3. Divide the working conditions according to the drive demand and motor efficiency characteristics, match the corresponding drive mode, and set an adaptive mode switching lag compensation mechanism to avoid frequent switching. Specifically, the following should be noted: The operating conditions are categorized as follows: when D < 0.3, it is considered a low-load condition; when 0.3 ≤ D < 0.6, it is considered a medium-load condition; when D ≥ 0.6, it is considered a high-load condition. The specific drive mode is as follows: In the low-load condition, the rear electric drive axle single motor + second gear mode is activated. At this time, the front electric drive axle main drive motor and auxiliary drive motor are stopped, and the rear electric drive axle drive motor operates at high efficiency. Operating within a range of ≥85%; under medium load conditions, activating the front electric drive axle main drive motor + rear electric drive axle drive motor + three-speed mode, with the front electric drive axle main drive motor efficiency... ≥88%, efficiency of the rear electric drive axle drive motor ≥85%; Under high load conditions, the three-motor coordinated + first gear mode is activated, and the auxiliary drive motor of the front electric drive axle is engaged through a synchronizer. The efficiency of all three motors must meet the following requirements. , , ≥80%; The adaptive mode: when D fluctuates within the threshold range, maintain the current mode for 1.5s before switching.

[0020] S4. During mode switching, a coordination strategy is used to achieve smooth operation between the motor and the transmission. Specifically, it should be noted that the coordinated strategy includes torque transition control, gear shifting coordination, and energy recovery linkage; the torque transition control: when switching from low load mode to medium load mode, the main drive motor of the front electric drive axle outputs torque... Dynamically incremented according to the following formula: ,in The target torque is represented by k, the torque transition coefficient is represented by t, and the transition time is represented by t; simultaneously, the torque of the rear electric drive axle drive motor is calculated according to... Decrease gradually to maintain a smooth transition of total torque, among which Indicates the initial torque; the gear shifting coordination: when gear shifting is required, synchronization is first achieved through motor speed adjustment, with the synchronization speed difference... ,in Indicates the current motor speed. Indicates the target gear speed, when Once the conditions are met, the synchronizer engages to complete the gear shift. During the shift, the motor torque must drop to below 30% of the rated torque. The energy recovery linkage: when the vehicle is in a deceleration condition (a < 0 and D < 0.2), it automatically switches to energy recovery mode, and the front and rear electric drive axle motors switch to generator mode to recover torque. The recovered electrical energy is directly stored in the battery, and the braking intensity must be ≤0.3g during the recovery process to avoid wheel lock-up. S5. Real-time monitoring of the impact during the switching process, and closed-loop adjustment by correcting the torque transition coefficient to control the impact within the set range. Specifically, it should be noted that the impact force... ,in This indicates the gear ratio of the current gear, r represents the wheel rolling radius, and f represents the rolling resistance coefficient; when the impact exceeds the impact threshold, the torque transition coefficient is corrected. Continue until the impact threshold is lowered to ensure a smooth switching process.

[0021] The driving conditions of heavy-duty commercial vehicles are characterized by "high dynamics and strong coupling"—power demand is affected by multiple factors such as load, gradient, vehicle speed, and road surface adhesion conditions, while also needing to consider battery status and motor efficiency. The design of multi-dimensional parameter acquisition in the solution is not a simple accumulation of parameters, but rather based on a closed-loop correlation logic of "power source - energy carrier - driving environment - vehicle status." The "power demand" of heavy-duty commercial vehicles is a complex variable with multi-dimensional coupling. The driving demand degree D calculation formula designed in the solution transforms dispersed physical quantities into a quantifiable unified index through mathematical modeling. Its rationality is reflected in: the numerator directly reflects the total power required for the vehicle to overcome inertia, gravity, and air resistance, quantifying the "absolute power demand"; the denominator incorporates the battery's maximum output power and SOC, reflecting the constraint of energy supply capacity on power output and avoiding power interruption caused by "demand exceeding supply"; the inverse of the road surface adhesion coefficient and the logarithm of the motor speed are introduced to correct the "safety boundary of power output" (low-adhesion roads require reduced power to avoid slippage) and the "dynamic response characteristics of the motor" (changes in motor torque output capability at high speeds), respectively. This quantitative logic, which integrates the four elements of "demand-supply-safety-dynamic characteristics," not only conforms to the basic principles of vehicle dynamics but also aligns with the collaborative characteristics of the "motor-battery" system in electric drive systems. This allows D to accurately reflect the "comprehensive demand intensity of the vehicle on the drive system under current operating conditions," providing a comparable and executable scientific basis for mode switching. The drive modes designed for low, medium, and high load conditions are not simply combinations of "motor quantity + gears," but rather precise adaptations based on the "differentiated operating conditions" of heavy commercial vehicles: Low load conditions utilize "single motor from the rear electric drive axle + second gear," leveraging the high-efficiency range of the single motor to reduce energy consumption, suitable for low-power demand scenarios such as highway cruising; medium load conditions utilize "dual main motors + third gear," improving power reserves through the collaboration of the two motors, while the high transmission ratio of the third gear balances vehicle speed and efficiency, suitable for medium loads and gentle slopes; high load conditions utilize "three motors + first gear," using the additional torque of the auxiliary motor and the low transmission ratio of the first gear to meet high-power demands such as climbing and rapid acceleration, while requiring the efficiency of the three motors to be ≥80% to control energy consumption. Meanwhile, the "lag compensation mechanism" (maintaining the current mode for 1.5s when the threshold range fluctuates) is designed for the "short-term fluctuations in operating conditions" (such as slight road undulations) common in commercial vehicles, avoiding system losses caused by frequent switching, reflecting a deep understanding of actual driving scenarios; the core reason for the "large switching impact and rapid wear of transmission components" in the existing technology is the "asynchrony" between motor torque and gear switching.The collaborative control strategy of the solution achieves precise matching of "torque-speed-gear" through a dynamic mathematical model. Its rationality lies in the following: the torque transition formula uses an exponential curve to simulate the "soft start" characteristic of motor torque, avoiding the impact caused by step torque changes; simultaneously, rear motor torque compensation ensures stable total torque, meeting the physical requirement of "shock resistance" in mechanical transmission systems; synchronous speed difference control during gear shifting, combined with a "torque drop below 30%" strategy, dynamically adjusts the synchronization accuracy using the drive demand degree D (D is larger under high load, allowing for a larger speed difference to prioritize power continuity), balancing "shifting smoothness" and "power response speed"; the energy recovery linkage mechanism binds the recovered torque to vehicle mass, deceleration intensity, and battery SOC, avoiding excessive recovery and battery damage at low SOC, and preventing wheel lock-up through "braking intensity" constraints, achieving synergy between "energy recovery and driving safety." The driving conditions of heavy commercial vehicles are highly random (such as sudden slope changes and load fluctuations), making fixed parameter control difficult to adapt to dynamic changes. The real-time monitoring and correction mechanism for the impact intensity j in the solution constructs a closed-loop control system of "perception-decision-execution-feedback": the calculation formula for the impact intensity j (related to the motor torque change rate, transmission ratio, driving resistance, etc.) directly quantifies the impact of power switching on vehicle smoothness, ensuring that the physical meaning of the feedback index is clear; the dynamic correction of the transition coefficient k (k increases with higher vehicle speed and decreases when the impact exceeds the limit) enables the system to adapt to different vehicle speeds and impact intensities, avoiding insufficient adaptability caused by "one-size-fits-all" control. This design gives the system "self-adjustment capability," and even when there are minor errors in parameter acquisition or sudden changes in operating conditions, it can still maintain stable operation through feedback correction, meeting the "high reliability" requirements of commercial vehicles.

[0022] Secondly: The accompanying drawings of the embodiments disclosed in this invention only involve the structures involved in the embodiments disclosed in this invention. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this invention can be combined with each other. In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for coordinated control of drive mode switching in an electric drive system for heavy-duty commercial vehicles, characterized in that, include: S1. Real-time collection of multi-dimensional operational data to provide a data foundation; S2. Based on the collected multi-dimensional operational data, the real-time driving demand of the vehicle is calculated using a specific formula, which serves as the core decision indicator for mode switching. S3. Divide the working conditions according to the drive demand and motor efficiency characteristics, match the corresponding drive mode, and set an adaptive mode switching lag compensation mechanism to avoid frequent switching. S4. During mode switching, a coordination strategy is used to achieve smooth operation between the motor and the transmission. S5. Real-time monitoring of the impact during the switching process, and closed-loop adjustment by correcting the torque transition coefficient to control the impact within the set range.

2. The method for coordinated control of drive mode switching in a heavy-duty commercial vehicle electric drive system according to claim 1, characterized in that: The multi-dimensional operating data includes motor parameters, battery parameters, vehicle status parameters, and environmental parameters; the motor parameters specifically include the speed of the front electric drive axle main drive motor. Output torque ,efficiency ; Rear electric drive axle drive motor speed Output torque ,efficiency Front electric drive axle auxiliary drive motor speed Output torque ,efficiency The battery parameters specifically include the current SOC value S and the output power. The vehicle state parameters specifically include driving speed v, acceleration a, load mass m, and gradient. The environmental parameters include the road surface adhesion coefficient. .

3. The method for coordinated control of drive mode switching in a heavy-duty commercial vehicle electric drive system according to claim 2, characterized in that: The driving demand Where g represents the acceleration due to gravity. The value represents the air resistance coefficient, and A represents the vehicle's frontal area. This indicates the battery's maximum output power.

4. The method for coordinated control of drive mode switching in a heavy-duty commercial vehicle electric drive system according to claim 1, characterized in that: The operating conditions are defined as follows: when D < 0.3, it is determined to be a low-load condition; when 0.3 ≤ D < 0.6, it is determined to be a medium-load condition; and when D ≥ 0.6, it is determined to be a high-load condition.

5. The method for coordinated control of drive mode switching in a heavy-duty commercial vehicle electric drive system according to claim 1, characterized in that: The specific drive mode is as follows: Under low load conditions, the rear electric drive axle single motor + second gear mode is activated. At this time, the front electric drive axle main drive motor and auxiliary drive motor are stopped, and the rear electric drive axle drive motor operates at high efficiency. Operating within a range of ≥85%; under medium load conditions, activating the front electric drive axle main drive motor + rear electric drive axle drive motor + three-speed mode, with the front electric drive axle main drive motor efficiency... ≥88%, efficiency of the rear electric drive axle drive motor ≥85%; Under high load conditions, the three-motor coordinated + first gear mode is activated, and the auxiliary drive motor of the front electric drive axle is engaged through a synchronizer. The efficiency of all three motors must meet the following requirements. , , ≥80%; The adaptive mode: when D fluctuates within the threshold range, maintain the current mode for 1.5s before switching.

6. The method for coordinated control of drive mode switching in a heavy-duty commercial vehicle electric drive system according to claim 1, characterized in that: The coordinated strategy includes torque transition control, gear shift coordination, and energy recovery linkage.

7. The method for coordinated control of drive mode switching in a heavy-duty commercial vehicle electric drive system according to claim 6, characterized in that: The torque transition control: When switching from low load mode to medium load mode, the main drive motor of the front electric drive axle outputs torque. Dynamically incremented according to the following formula: ,in The target torque is represented by k, the torque transition coefficient is represented by t, and the transition time is represented by t; simultaneously, the torque of the rear electric drive axle drive motor is calculated according to... Decrease gradually to maintain a smooth transition of total torque, among which This indicates the initial torque.

8. The method for coordinated control of drive mode switching in a heavy-duty commercial vehicle electric drive system according to claim 6, characterized in that: The gear shifting coordination: When gear shifting is required, synchronization is first achieved through motor speed adjustment, with the synchronization speed difference... ,in Indicates the current motor speed. Indicates the target gear speed, when Once the conditions are met, the synchronizer engages to complete the gear shift. During the gear shift, the motor torque must be reduced to less than 30% of the rated torque.

9. The method for coordinated control of drive mode switching in a heavy-duty commercial vehicle electric drive system according to claim 6, characterized in that: The energy recovery linkage is as follows: when the vehicle is in a deceleration condition (a < 0 and D < 0.2), it automatically switches to energy recovery mode, and the front and rear electric drive axle motors switch to generator mode to recover torque. The recovered electrical energy is directly stored in the battery, and the braking intensity must be ≤0.3g during the recovery process to avoid wheel lock-up.

10. The method for coordinated control of drive mode switching in a heavy-duty commercial vehicle electric drive system according to claim 3, characterized in that: The impact ,in This indicates the gear ratio of the current gear, r represents the wheel rolling radius, and f represents the rolling resistance coefficient; when the impact exceeds the impact threshold, the torque transition coefficient is corrected. Continue until the impact threshold is lowered to ensure a smooth switching process.

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