A logistics vehicle energy recovery control method and system

Abstract

This invention relates to an energy recovery control method and system for logistics vehicles, belonging to the field of vehicle technology. The method includes: real-time acquisition of the logistics vehicle's state information under braking conditions; calculation of the vertical wheel loads based on the state information; determination of the logistics vehicle's center of gravity offset based on the vertical wheel loads; assessment of whether there is a safety risk based on the vertical wheel loads; execution of an energy recovery control strategy when there is no safety risk; adjustment of the logistics vehicle's center of gravity based on the center of gravity offset when there is a safety risk; optimization of the vertical wheel loads based on the adjusted center of gravity; determination of the regenerative braking torque based on a constructed mapping model of wheel load distribution and regenerative braking torque and the optimized vertical wheel loads; determination of the regenerative braking upper limit based on the optimized vertical wheel loads; and execution of a new energy recovery control strategy based on the regenerative braking torque and the regenerative braking upper limit, thereby improving energy recovery efficiency and braking safety.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a method and system for energy recovery control of logistics vehicles. Background Technology

[0002] In actual use, logistics vehicles may experience significant changes in their center of gravity due to factors such as unfixed cargo loading locations, large variations in load mass, and potential cargo imbalances during operation.

[0003] However, existing energy recovery control methods still rely on a fixed center of gravity assumption, which fails to adapt to such dynamic changes. This can easily lead to excessive braking force on a certain axle or wheel, causing local wheels to reach their adhesion limits prematurely. Ultimately, this limits energy recovery or even weakens it due to safety strategies, severely impacting energy recovery efficiency. Furthermore, when the center of gravity shifts forward or laterally, the vehicle load distribution changes significantly, with increased vertical load on the front axle or inner wheel and correspondingly decreased vertical load on the rear axle or outer wheel. If energy recovery is still performed according to the conventional regenerative braking distribution strategy, low-load wheels are prone to slippage, forcing the system to frequently reduce regenerative braking torque to maintain vehicle stability. Therefore, under complex load conditions, it is difficult to simultaneously ensure braking safety and energy recovery efficiency, failing to fully leverage the energy-saving and emission-reduction advantages of new energy logistics vehicles. Summary of the Invention

[0004] In view of this, it is necessary to provide a method and system for controlling energy recovery in logistics vehicles to solve the technical problem of simultaneously ensuring braking safety and energy recovery efficiency under complex load conditions.

[0005] To address the aforementioned problems, in a first aspect, the present invention provides a method for controlling energy recovery in a logistics vehicle, comprising: Real-time acquisition of the status information of the logistics vehicle under braking conditions; determination of the braking intensity of the logistics vehicle and the energy recovery control strategy and energy recovery upper limit corresponding to the braking intensity based on the status information. The vertical load on the wheels of the logistics vehicle is calculated based on the state information, and the center of gravity offset of the logistics vehicle is determined based on the vertical load on the wheels. Based on the vertical load of the wheels, it is determined whether there is a safety risk to the logistics vehicle. When there is no safety risk, the energy recovery control strategy is executed. When there is a safety risk, the center of gravity of the logistics vehicle is adjusted based on the center of gravity offset. Based on the adjusted center of gravity, the vertical load of the wheels is optimized. Based on the constructed mapping model of wheel load distribution and regenerative braking torque and the optimized vertical load of the wheels, the regenerative braking torque is determined. Based on the optimized vertical load of the wheels, the upper limit of regenerative braking is determined. Based on the regenerative braking torque and the upper limit of regenerative braking, a new energy recovery control strategy is executed.

[0006] In one possible implementation, the state information includes the structural parameters of the logistics vehicle, the structural parameters of the center of gravity adjustment mechanism, the SOC of the power battery, the operating status of the motor, the allowable range of energy recovery, the braking request signal, the vehicle speed, the longitudinal deceleration, the wheel speed signal, the suspension displacement, the wheel load sensor information, and the vehicle attitude parameters. The structural parameters of the logistics vehicle include the wheelbase, the track width, and the vehicle body mass distribution range. The structural parameters of the center of gravity adjustment mechanism include the maximum adjustment stroke and the response speed.

[0007] In one possible implementation, the braking intensity of the logistics vehicle includes light braking, moderate braking, and forced braking.

[0008] In one possible implementation, calculating the vertical wheel load of the logistics vehicle based on the state information, and determining the center of gravity offset of the logistics vehicle based on the vertical wheel load, includes: Based on the state information, the relationship between wheel load sensing information and vehicle dynamics is constructed, and the vertical load of each wheel of the logistics vehicle is calculated based on the relationship between wheel load sensing information and vehicle dynamics. The differences in load between the front and rear axles and the left and right wheels of the logistics vehicle are determined based on the vertical load of each wheel. The center of gravity of the logistics vehicle is then calculated in reverse based on the differences in load between the front and rear axles and the left and right wheels and the initial center of gravity of the logistics vehicle, so as to determine the offset of the center of gravity of the logistics vehicle.

[0009] In one possible implementation, the safety risks include wheel vertical load safety risks, tire adhesion utilization safety risks, and wheel slippage safety risks.

[0010] In one possible implementation, determining whether a logistics vehicle poses a safety risk based on the vertical load on the wheels includes: The vertical load of each wheel is determined based on the vertical load of the wheel, and the average load of the wheel is calculated based on the vertical load of each wheel. When the vertical load of each wheel is less than the percentage threshold of the average load of the wheel, the logistics vehicle has a safety risk. The adhesion utilization rate of each wheel is determined, and the friction force of each wheel is determined based on the adhesion utilization rate of each wheel and the vertical load. When the friction force of each wheel is greater than or equal to the maximum friction force of each wheel, the logistics vehicle has a safety risk. The regenerative braking torque of each wheel is determined. When the regenerative braking torque is greater than the product of the vertical load of each wheel and the rolling radius of the wheel, the logistics vehicle has a safety risk.

[0011] In one possible implementation, executing the energy recovery control strategy when there is no safety risk includes: The regenerative braking torque of each wheel is determined based on the vertical load of the wheel, and the regenerative braking torque of each wheel is dynamically distributed so that the difference in vertical load between each wheel is less than a preset difference. Specifically, the regenerative braking torque is limited for wheels with a vertical load less than a preset threshold, and the regenerative braking torque is increased for wheels with a vertical load greater than or equal to the preset threshold.

[0012] In one possible implementation, adjusting the center of gravity of the logistics vehicle based on the center of gravity offset includes: The direction, magnitude, and priority of the center of gravity adjustment of the logistics vehicle are determined based on the braking conditions, wheel load distribution, and center of gravity offset. The center of gravity of the logistics vehicle is adjusted based on the center of gravity adjustment direction, adjustment range, and adjustment priority.

[0013] In one possible implementation, adjusting the center of gravity of the logistics vehicle based on the center of gravity offset further includes: The speed at which the center of gravity of the logistics vehicle is adjusted is limited, and the execution status of the center of gravity adjustment is monitored in real time.

[0014] Secondly, the present invention also provides an energy recovery control system for a logistics vehicle, comprising: The information acquisition module is used to collect the status information of the logistics vehicle under braking conditions in real time, and determine the braking intensity of the logistics vehicle and the energy recovery control strategy and energy recovery upper limit corresponding to the braking intensity based on the status information. The center of gravity offset determination module is used to calculate the vertical load of the wheels of the logistics vehicle based on the state information, and to determine the center of gravity offset of the logistics vehicle based on the vertical load of the wheels. The energy recovery control module is used to determine whether there is a safety risk to the logistics vehicle based on the vertical load of the wheels. When there is no safety risk, the energy recovery control strategy is executed. When there is a safety risk, the center of gravity of the logistics vehicle is adjusted based on the center of gravity offset. The vertical load of the wheels is optimized based on the adjusted center of gravity. The regenerative braking torque is determined based on the constructed mapping model of wheel load distribution and regenerative braking torque and the optimized vertical load of the wheels. The upper limit of regenerative braking is determined based on the optimized vertical load of the wheels. A new energy recovery control strategy is executed based on the regenerative braking torque and the upper limit of regenerative braking.

[0015] The beneficial effects of this invention are as follows: It determines whether there is a safety risk to the logistics vehicle based on the vertical load of the wheels. When there is no safety risk, an energy recovery control strategy is executed. When there is a safety risk, the center of gravity of the logistics vehicle is adjusted based on the center of gravity offset. The vertical load of the wheels is optimized based on the adjusted center of gravity. The regenerative braking torque is determined based on the constructed mapping model of wheel load distribution and regenerative braking torque, and the optimized vertical load of the wheels. The upper limit of regenerative braking is determined based on the optimized vertical load of the wheels. A new energy recovery control strategy is executed based on the regenerative braking torque and the upper limit of regenerative braking. Optimizing the vertical load of the wheels based on the adjusted center of gravity proactively suppresses the safety risk of low-load wheels, preventing the energy recovery control from frequently triggering the protection mechanism, thereby ensuring the stability of the regenerative braking process, significantly reducing energy recovery interruptions, improving overall recovery stability, and ensuring vehicle braking safety. By adjusting the center of gravity and the energy recovery control strategy, adjusting the vertical load of the wheels, and dynamically optimizing the center of gravity position, it avoids large fluctuations in energy recovery performance due to load changes, significantly improving the average energy recovery efficiency of the new energy logistics vehicle, and balancing the braking safety and energy recovery efficiency of the logistics vehicle. Attached Figure Description

[0016] 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.

[0017] Figure 1 A flowchart illustrating an embodiment of the energy recovery control method for logistics vehicles provided by the present invention; Figure 2 A schematic diagram of the overall energy recovery process of the energy recovery control method for logistics vehicles provided by the present invention; Figure 3 This is a schematic diagram of an embodiment of the energy recovery control system for logistics vehicles provided by the present invention. Detailed Implementation

[0018] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0019] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0020] A specific embodiment of the present invention discloses a method for controlling energy recovery in logistics vehicles, such as... Figure 1 As shown, the energy recovery control method for logistics vehicles includes: S101. Real-time acquisition of the status information of the logistics vehicle under braking conditions, and determination of the braking intensity of the logistics vehicle and the corresponding energy recovery control strategy and energy recovery upper limit based on the status information.

[0021] S102. Calculate the vertical load of the logistics vehicle's wheels based on the state information, and determine the center of gravity offset of the logistics vehicle based on the vertical load of the wheels.

[0022] S103. Determine whether there is a safety risk to the logistics vehicle based on the vertical load of the wheels. If there is no safety risk, execute the energy recovery control strategy. If there is a safety risk, adjust the center of gravity of the logistics vehicle based on the center of gravity offset, optimize the vertical load of the wheels based on the adjusted center of gravity, determine the regenerative braking torque based on the constructed mapping model of wheel load distribution and regenerative braking torque and the optimized vertical load of the wheels, determine the upper limit of regenerative braking based on the optimized vertical load of the wheels, and execute a new energy recovery control strategy based on the regenerative braking torque and the upper limit of regenerative braking.

[0023] It should be noted that by optimizing the vertical load on the wheels based on the adjusted center of gravity, the safety risks of low-load wheels are suppressed in advance, and the energy recovery control no longer frequently triggers the protection mechanism. This ensures the stability of the regenerative braking process, significantly reduces energy recovery interruptions, improves overall recovery stability, and guarantees vehicle braking safety. By adjusting the center of gravity and energy recovery control strategy, adjusting the vertical load on the wheels, and dynamically optimizing the center of gravity position, large fluctuations in energy recovery performance due to load changes are avoided, significantly improving the average energy recovery efficiency of new energy logistics vehicles, and balancing the braking safety and energy recovery efficiency of logistics vehicles.

[0024] In some embodiments, step S101 involves real-time acquisition of the logistics vehicle's status information under braking conditions. This status information includes the logistics vehicle's structural parameters, the structural parameters of the center of gravity adjustment mechanism, the power battery's state of charge (SOC), the motor's operating status, the allowable range of energy recovery, braking request signals, vehicle speed, longitudinal deceleration, wheel speed signals, suspension displacement, wheel load sensor information, and vehicle attitude parameters. The logistics vehicle's structural parameters include wheelbase, track width, and vehicle mass distribution range. The center of gravity adjustment mechanism's structural parameters include maximum adjustment stroke and response speed. During the power-on or startup phase of the new energy logistics vehicle, system initialization is completed, including reading vehicle structural parameters such as wheelbase, track width, and vehicle mass distribution. The system acquires structural parameters of the center of gravity adjustment mechanism, such as maximum adjustment stroke and response speed, monitors the SOC of the power battery, the working status of the motor and the allowable range of energy recovery, and establishes a mapping model between wheel load distribution and regenerative braking torque under braking conditions. When the logistics vehicle is in motion, it collects key information such as brake pedal opening or brake request signal, current vehicle speed and longitudinal deceleration, wheel speed signals of the four wheels, suspension displacement or wheel load sensor signals, and vehicle attitude parameters such as longitudinal and lateral acceleration and yaw rate. All collected information is filtered to eliminate noise interference and data consistency is ensured through precise time synchronization before comprehensive analysis.

[0025] Based on state information, the braking intensity of the logistics vehicle, as well as the corresponding energy recovery control strategy and energy recovery limit, are determined. When the energy recovery reaches the limit (such as when the battery is close to full charge or the temperature is too high), the regenerative braking torque will be actively reduced, or even the energy recovery mode will be completely exited to prevent overcharging or system overload. The energy recovery limit will dynamically limit the actual output range of the regenerative braking torque. According to the braking request signal and vehicle deceleration, the braking intensity of the logistics vehicle is accurately determined. The braking intensity includes light braking, medium braking, and forced braking. Light braking corresponds to the energy recovery priority condition of the energy recovery control strategy, medium braking corresponds to the condition that balances recovery and stability of the energy recovery control strategy, and forced braking corresponds to the condition that the recovery of the energy recovery control strategy is limited. Priority is given to ensuring the driving safety of the logistics vehicle. Different braking levels correspond to different center of gravity adjustment strategies and energy recovery limits, which can make optimal energy recovery decisions under various braking intensities, balancing safety and energy recovery efficiency.

[0026] In some embodiments, in step S102, the vertical load of the wheels of the logistics vehicle is calculated based on the state information; the center of gravity offset of the logistics vehicle is determined based on the vertical load of the wheels; the relationship between wheel load sensing information and vehicle dynamics is constructed based on the state information; the vertical load of each wheel of the logistics vehicle is calculated based on the relationship between wheel load sensing information and vehicle dynamics; the difference between the front and rear axles and the left and right wheel loads of the logistics vehicle is determined based on the vertical load of each wheel; the center of gravity of the logistics vehicle is back-calculated based on the difference between the front and rear axles and the left and right wheel loads and the initial center of gravity of the logistics vehicle to determine the center of gravity offset of the logistics vehicle; the real-time vertical load of each wheel is accurately calculated based on the relationship between wheel load sensing information and vehicle dynamics; the difference between the front and rear axles and the left and right wheel loads is identified; and the longitudinal and lateral offsets of the current center of gravity of the entire vehicle are back-calculated through a mechanical model.

[0027] In some embodiments, in step S103, a safety risk is determined based on the wheel vertical load. The safety risks include wheel vertical load safety risk, tire adhesion utilization safety risk, and wheel slippage safety risk. The wheel vertical load provides the wheel load distribution of the logistics vehicle, i.e., the vertical load of each wheel. Based on the vertical load of each wheel, it can be determined whether the vertical load of a particular wheel is too low. When the vertical load of a wheel is less than 20% to 30% of the average wheel load, it will cause the tire to tend to lift off the ground, and the wheel will have almost no adhesion, thus causing wheel slippage. Vertical load safety risks exist. When the adhesion utilization rate of a wheel approaches its limit, further increasing the regenerative braking torque will cause slippage, thus posing a safety risk to tire adhesion utilization. Distributing the regenerative torque through energy recovery control strategies may also introduce wheel slippage safety risks. The vertical load of each wheel is determined based on its vertical load, and the average load of the wheel is calculated based on the vertical load of each wheel. When the vertical load of each wheel is less than the 100% threshold of the average load of the wheel, the logistics vehicle faces a safety risk, which is the wheel vertical load safety risk. , in, For the first Vertical load on each wheel The average vertical load on the wheel; The adhesion utilization rate of each wheel is determined. Based on the adhesion utilization rate and vertical load, the friction force of each wheel is determined. When the friction force of each wheel is greater than or equal to the maximum friction force of each wheel, the logistics vehicle faces a safety risk. This safety risk is the tire adhesion utilization rate safety risk, which is as follows: , in, For the first The adhesion utilization rate of each wheel is normal. , As a constraint, the tire adhesion utilization rate is close to the limit when: The tires are close to their maximum friction limit; increasing braking force further will cause them to slip. These are calibration coefficients, taken as real-time estimates or empirical / calibrated values, typically 1. , For the first The friction of each wheel; Determine the regenerative braking torque of each wheel. When the regenerative braking torque is greater than the product of the vertical load on each wheel and the wheel's rolling radius, the logistics vehicle faces a safety risk, which is the wheel slippage safety risk. The wheel slippage safety risk is as follows: , in, For the first The regenerative braking torque of each wheel (the torque generated by the motor's regenerative braking). Let be the rolling radius of the wheel, when At that time, the wheel will definitely slip; When there is no safety risk, the energy recovery control strategy is implemented. That is, when there are no restrictions on the energy recovery control strategy, the energy recovery control strategy corresponding to the braking intensity of the logistics vehicle at the current moment is implemented. The braking intensity of the logistics vehicle at the current moment can be light braking or moderate braking. The specific energy recovery control strategy is to determine the regenerative braking torque of each wheel based on the vertical load of the wheel, and to dynamically distribute the regenerative braking torque of each wheel so that the vertical load of each wheel tends to be uniform. Among them, the regenerative braking torque is limited for wheels with a vertical load less than the preset threshold, and the regenerative braking torque is increased for wheels with a vertical load greater than or equal to the preset threshold. When one of the following safety risks occurs—wheel vertical load safety risk, tire adhesion utilization safety risk, or wheel slippage safety risk—the energy recovery control strategy will be limited, requiring the initiation of center of gravity adjustment. When a safety risk exists, the center of gravity of the logistics vehicle is adjusted based on the center of gravity offset. The wheel vertical load is then optimized based on the adjusted center of gravity. The regenerative braking torque is determined based on the constructed mapping model of wheel load distribution and regenerative braking torque, and the optimized wheel vertical load. The upper limit of regenerative braking is determined based on the optimized wheel vertical load. A new energy recovery control strategy is then executed based on the regenerative braking torque and the upper limit of regenerative braking. The process of adjusting the center of gravity of the logistics vehicle involves determining the direction, magnitude, and priority of the center of gravity adjustment based on the braking conditions, wheel load distribution, and center of gravity offset. The system adjusts the center of gravity of the logistics vehicle. After the center of gravity is adjusted, the target center of gravity adjustment plan is calculated based on the braking conditions and wheel load status. This includes determining the direction of center of gravity adjustment (longitudinal forward / backward movement, lateral inward movement), the adjustment range, and the adjustment priority (longitudinal first, then lateral, or vice versa). Control commands are sent to the center of gravity adjustment actuator to make the cargo box or load platform move smoothly along the set trajectory. At the same time, the center of gravity adjustment speed is strictly limited to avoid disturbing the longitudinal deceleration of the vehicle. The adjustment execution status is monitored in real time and can be carried out dynamically during braking to ensure that the center of gravity adjustment action is smooth and precise and does not affect the driver's braking feel and vehicle stability. This achieves seamless coordination between structural adjustment and braking control. During the center of gravity adjustment process, the wheel load distribution is optimized by actively changing the position of the vehicle's center of gravity, thereby releasing the limited energy recovery potential and achieving the best balance between safety and efficiency. Based on the wheel load distribution after the center of gravity adjustment, the regenerative braking torque of each drive motor is recalculated. The upper limit of regenerative braking is determined according to the real-time vertical load of each wheel. A new energy recovery control strategy is implemented based on the calculated regenerative braking torque and the upper limit of regenerative braking. Torque limitation is implemented on low-load wheels, and the recovery contribution ratio is increased on high-load wheels. When the new energy recovery control strategy is implemented, key parameters such as wheel speed difference, tire slip ratio, and vehicle attitude change are continuously monitored. When a potential unstable trend is detected, the center of gravity position is dynamically corrected or the energy recovery intensity is reduced to form a closed-loop control mechanism. When the logistics vehicle stops braking or enters a stable driving state, the center of gravity adjustment mechanism slowly returns to the normal position to avoid sudden position changes affecting the vehicle's dynamic performance. The energy recovery control strategy switches to cruise or coasting mode. After adjusting the energy recovery intensity according to the current vehicle speed and road conditions, it enters a standby monitoring state to continuously collect vehicle status information and prepare for the next braking energy recovery.

[0028] Please refer to the overall process diagram of its energy recovery. Figure 2 ,like Figure 2As shown, the system reads vehicle structural parameters during vehicle initialization. During vehicle operation, it collects data on vehicle status and braking status. Based on the braking request signal and vehicle deceleration, it identifies the braking condition and calculates the wheel vertical load and the current offset of the vehicle's center of gravity under the braking condition. It determines whether energy recovery is limited based on the wheel vertical load; if there is no safety risk, energy recovery is unrestricted, and if there is a safety risk, it is limited. If there are no limitations, the current energy recovery strategy is maintained, and regenerative braking force is distributed based on the current wheel vertical load. If limitations exist, it automatically enters the center of gravity adjustment process, actively changing the vehicle's center of gravity position to optimize wheel load distribution. After confirming the need for center of gravity adjustment, it actively adjusts the vehicle's center of gravity position during braking, transferring the vertical load to the wheels with stronger energy recovery capabilities. This increases the regenerative braking torque that the wheels can withstand, expands the energy recovery working range, and achieves a higher proportion of regenerative braking participation under the same braking intensity, significantly improving the energy recovery amount per unit braking event and breaking through the wheel load limitations of traditional energy recovery systems. Furthermore, it suppresses low-load wheels in advance through center of gravity adjustment. By mitigating adhesion risks, energy recovery control no longer frequently triggers protection mechanisms, thus ensuring the stability of the regenerative braking process. This makes the energy recovery process smoother and more continuous, significantly reducing recovery interruptions and improving overall recovery stability while ensuring vehicle braking safety. During each braking process, the center of gravity and recovery strategy are adaptively adjusted. By sensing load distribution in real time and dynamically optimizing the center of gravity position, significant fluctuations in energy recovery performance due to load changes are avoided. This significantly improves the average energy recovery efficiency of new energy logistics vehicles in real-world operating scenarios, especially in frequent start-stop conditions such as urban delivery, effectively extending vehicle range and improving overall energy efficiency. Center of gravity adjustment improves braking conditions from a structural perspective. By actively optimizing wheel load distribution, it reduces passive reliance on safety systems such as ESC and ABS. When the wheel load distribution is more balanced, the adhesion utilization rate of each wheel increases, significantly reducing the risk of slippage during braking. This greatly reduces the intervention frequency of the stability control system. This coordinated approach of structural adjustment and control not only improves the synergy between braking control and energy recovery but also improves the overall vehicle driving quality, making the braking process smoother and energy recovery more efficient.

[0029] In summary, the energy recovery control method for logistics vehicles provided by this invention collects the state information of the logistics vehicle under braking conditions in real time, determines the braking intensity of the logistics vehicle and the corresponding energy recovery control strategy and energy recovery upper limit based on the state information; calculates the vertical load of the logistics vehicle's wheels based on the state information, determines the center of gravity offset of the logistics vehicle based on the vertical load of the wheels; judges the safety risk of the logistics vehicle based on the vertical load of the wheels, executes the energy recovery control strategy when there is no safety risk, and adjusts the center of gravity of the logistics vehicle based on the center of gravity offset when there is a safety risk, optimizes the vertical load of the wheels based on the adjusted center of gravity, determines the regenerative braking torque based on the constructed mapping model of wheel load distribution and regenerative braking torque and the optimized vertical load of the wheels, determines the regenerative braking upper limit based on the optimized vertical load of the wheels, and executes a new energy recovery control strategy based on the regenerative braking torque and the regenerative braking upper limit, thereby improving energy recovery efficiency and braking safety.

[0030] To better implement the energy recovery control method for logistics vehicles in this embodiment of the invention, based on the energy recovery control method for logistics vehicles, the corresponding method is as follows: Figure 3 As shown, this embodiment of the invention also provides an energy recovery control system for a logistics vehicle. The energy recovery control system 300 for the logistics vehicle includes: The information acquisition module 301 is used to collect the status information of the logistics vehicle under braking conditions in real time, and determine the braking intensity of the logistics vehicle and the energy recovery control strategy and energy recovery upper limit corresponding to the braking intensity based on the status information. The center of gravity offset determination module 302 is used to calculate the vertical load of the wheels of the logistics vehicle based on the state information, and to determine the center of gravity offset of the logistics vehicle based on the vertical load of the wheels. The energy recovery control module 303 is used to determine whether there is a safety risk to the logistics vehicle based on the vertical load of the wheels. When there is no safety risk, the energy recovery control strategy is executed. When there is a safety risk, the center of gravity of the logistics vehicle is adjusted based on the center of gravity offset. The vertical load of the wheels is optimized based on the adjusted center of gravity. The regenerative braking torque is determined based on the constructed mapping model of wheel load distribution and regenerative braking torque and the optimized vertical load of the wheels. The upper limit of regenerative braking is determined based on the optimized vertical load of the wheels. A new energy recovery control strategy is executed based on the regenerative braking torque and the upper limit of regenerative braking.

[0031] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A logistics vehicle energy recovery control method, characterized by, include: Real-time acquisition of the status information of the logistics vehicle under braking conditions; determination of the braking intensity of the logistics vehicle and the energy recovery control strategy and energy recovery upper limit corresponding to the braking intensity based on the status information. The vertical load on the wheels of the logistics vehicle is calculated based on the state information, and the center of gravity offset of the logistics vehicle is determined based on the vertical load on the wheels. Based on the vertical load of the wheels, it is determined whether there is a safety risk to the logistics vehicle. When there is no safety risk, the energy recovery control strategy is executed. When there is a safety risk, the center of gravity of the logistics vehicle is adjusted based on the center of gravity offset. Based on the adjusted center of gravity, the vertical load of the wheels is optimized. Based on the constructed mapping model of wheel load distribution and regenerative braking torque and the optimized vertical load of the wheels, the regenerative braking torque is determined. Based on the optimized vertical load of the wheels, the upper limit of regenerative braking is determined. Based on the regenerative braking torque and the upper limit of regenerative braking, a new energy recovery control strategy is executed.

2. The method of claim 1, wherein, The status information includes the structural parameters of the logistics vehicle, the structural parameters of the center of gravity adjustment mechanism, the SOC of the power battery, the working status of the motor, the allowable range of energy recovery, the braking request signal, the vehicle speed, the longitudinal deceleration, the wheel speed signal, the suspension displacement, the wheel load sensor information, and the vehicle attitude parameters. The structural parameters of the logistics vehicle include the wheelbase, the track width, and the vehicle body mass distribution range. The structural parameters of the center of gravity adjustment mechanism include the maximum adjustment stroke and the response speed.

3. The method of claim 1, wherein, The braking intensity of the logistics vehicle includes light braking, medium braking, and forced braking.

4. The method of claim 2, wherein, The step of calculating the vertical load on the wheels of the logistics vehicle based on the state information, and determining the center-of-gravity offset of the logistics vehicle based on the vertical load on the wheels, includes: Based on the state information, the relationship between wheel load sensing information and vehicle dynamics is constructed, and the vertical load of each wheel of the logistics vehicle is calculated based on the relationship between wheel load sensing information and vehicle dynamics. The differences in load between the front and rear axles and between the left and right wheels of the logistics vehicle are determined based on the vertical load of each wheel. The center of gravity of the logistics vehicle is then calculated in reverse based on the differences in load between the front and rear axles and between the left and right wheels and the initial center of gravity of the logistics vehicle, so as to determine the offset of the center of gravity of the logistics vehicle.

5. The method of claim 1, wherein, The safety risks include wheel vertical load safety risks, tire adhesion utilization safety risks, and wheel slippage safety risks.

6. The method of claim 5, wherein, The method of determining whether a logistics vehicle poses a safety risk based on the vertical load on the wheels includes: The vertical load of each wheel is determined based on the vertical load of the wheel, and the average load of the wheel is calculated based on the vertical load of each wheel. When the vertical load of each wheel is less than the percentage threshold of the average load of the wheel, the logistics vehicle has a safety risk. The adhesion utilization rate of each wheel is determined, and the friction force of each wheel is determined based on the adhesion utilization rate of each wheel and the vertical load. When the friction force of each wheel is greater than or equal to the maximum friction force of each wheel, the logistics vehicle has a safety risk. The regenerative braking torque of each wheel is determined. When the regenerative braking torque is greater than the product of the vertical load of each wheel and the rolling radius of the wheel, the logistics vehicle has a safety risk.

7. The method of claim 5, wherein, When there is no safety risk, the energy recovery control strategy is executed, including: The regenerative braking torque of each wheel is determined based on the vertical load of the wheel, and the regenerative braking torque of each wheel is dynamically distributed so that the difference in vertical load between each wheel is less than a preset difference. Specifically, the regenerative braking torque is limited for wheels with a vertical load less than a preset threshold, and the regenerative braking torque is increased for wheels with a vertical load greater than or equal to the preset threshold.

8. The method of claim 4, wherein, The adjustment of the center of gravity of the logistics vehicle based on the center of gravity offset includes: The direction, magnitude, and priority of the center of gravity adjustment of the logistics vehicle are determined based on the braking conditions, wheel load distribution, and center of gravity offset. The center of gravity of the logistics vehicle is adjusted based on the center of gravity adjustment direction, adjustment range, and adjustment priority.

9. The method of claim 8, wherein, The adjustment of the center of gravity of the logistics vehicle based on the center of gravity offset further includes: The speed at which the center of gravity of the logistics vehicle is adjusted is limited, and the execution status of the center of gravity adjustment is monitored in real time.

10. A logistics vehicle energy recovery control system, characterized by, include: The information acquisition module is used to collect the status information of the logistics vehicle under braking conditions in real time, and determine the braking intensity of the logistics vehicle and the energy recovery control strategy and energy recovery upper limit corresponding to the braking intensity based on the status information. The center of gravity offset determination module is used to calculate the vertical load of the wheels of the logistics vehicle based on the state information, and to determine the center of gravity offset of the logistics vehicle based on the vertical load of the wheels. The energy recovery control module is used to determine whether there is a safety risk to the logistics vehicle based on the vertical load of the wheels. When there is no safety risk, the energy recovery control strategy is executed. When there is a safety risk, the center of gravity of the logistics vehicle is adjusted based on the center of gravity offset. The vertical load of the wheels is optimized based on the adjusted center of gravity. The regenerative braking torque is determined based on the constructed mapping model of wheel load distribution and regenerative braking torque and the optimized vertical load of the wheels. The upper limit of regenerative braking is determined based on the optimized vertical load of the wheels. A new energy recovery control strategy is executed based on the regenerative braking torque and the upper limit of regenerative braking.

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