Braking energy recovery capacity determination method and system and storage medium

Abstract

The invention provides a braking energy recovery capacity determination method and system and a storage medium. The method comprises the steps that the axle load transfer amount is determined according to driving information of a vehicle; according to the dynamic detection value of the vehicle front axle load, the first front braking force generated by the vehicle front axle due to vehicle sliding energy recovery and the axle load transfer amount, the theoretical value of the vehicle front axle braking energy recovery capacity is determined; according to the dynamic detection value of the axle load of the rear axle of the vehicle, first rear braking force generated by the rear axle of the vehicle due to vehicle sliding energy recovery and the axle load transfer amount, the theoretical value of the braking energy recovery capacity of the rear axle of the vehicle is determined; and determining the upper limit value of the braking energy recovery capacity of the front axle of the vehicle and the upper limit value of the braking energy recovery capacity of the rear axle of the vehicle according to the reference value of the braking energy recovery capacity of the vehicle output by the vehicle control unit and the theoretical value. The method aims at determining the more reasonable upper limit value of the braking energy recovery capacity and providing a reference basis for ensuring the maximum braking energy recovery efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of brake energy recovery, in particular to a brake energy recovery capability determination method, system and storage medium. BACKGROUND

[0002] With the continuous progress of electric vehicle technology, brake energy recovery technology has developed rapidly. Brake energy recovery technology is a technology that converts vehicle kinetic energy into electrical energy and stores it in the battery during vehicle braking or inertial sliding, which can improve the energy utilization efficiency of the vehicle and increase the cruising range of the electric vehicle.

[0003] In actual application, brake energy recovery capability is the basis for the whole vehicle controller to execute brake force distribution, and the determination accuracy of brake energy recovery capability directly affects the distribution result of brake force and determines the brake energy recovery efficiency.

[0004] Therefore, the present application is proposed. SUMMARY

[0005] The present application aims to provide a brake energy recovery capability determination method, system and storage medium, and the purpose is to determine a more reasonable and more accurate upper limit value of brake energy recovery capability, and to provide a high-quality reference basis for maximizing brake energy recovery efficiency.

[0006] In a first aspect, the embodiments of the present application provide a brake energy recovery capability determination method, comprising: determining an axle load transfer amount according to the driving information of the vehicle; determining a theoretical value of the front axle brake energy recovery capability of the vehicle according to the dynamic detection value of the front axle load of the vehicle, the first front brake force generated by the vehicle sliding energy recovery of the vehicle front axle and the axle load transfer amount, and determining a theoretical value of the rear axle brake energy recovery capability of the vehicle according to the dynamic detection value of the rear axle load of the vehicle, the first rear brake force generated by the vehicle sliding energy recovery of the vehicle rear axle and the axle load transfer amount; determining an upper limit value of the front axle brake energy recovery capability of the vehicle and an upper limit value of the rear axle brake energy recovery capability of the vehicle according to the reference value of the vehicle brake energy recovery capability output by the whole vehicle controller, the theoretical value of the front axle brake energy recovery capability of the vehicle and the theoretical value of the rear axle brake energy recovery capability of the vehicle.

[0007] According to the technical scheme provided by the embodiments of the present application, the axle load transfer amount is determined according to the driving information of the vehicle, which can be selected, comprising: inputting the driving information into an axle load transfer model to obtain the axle load transfer amount; Alternatively, according to the driving information, a matched axle load transfer amount is determined from a first preset relationship, the first preset relationship being a corresponding relationship between driving information and axle load transfer amount.

[0008] According to the technical scheme provided by the embodiment of the application, optionally, the vehicle front axle comprises a left front axle and a right front axle, and the corresponding dynamic detection value of the axle load comprises a dynamic detection value of the left front axle load and a dynamic detection value of the right front axle load. The theoretical value of the vehicle front axle braking energy recovery capability is determined according to the dynamic detection value of the vehicle front axle load, the first front brake force generated by the vehicle front axle due to vehicle coasting energy recovery, and the axle load transfer amount, and comprises: The sum of the dynamic detection value of the left front axle load and the dynamic detection value of the right front axle load is determined. The reference value of the vehicle front axle load is determined according to the sum of the dynamic detection values and the axle load transfer amount. The theoretical value of the vehicle front axle braking energy recovery capability is determined according to the reference value of the vehicle front axle load and the first front brake force generated by the vehicle front axle due to vehicle coasting energy recovery.

[0009] According to the technical scheme provided by the embodiment of the application, optionally, the theoretical value of the vehicle front axle braking energy recovery capability is determined according to the reference value of the vehicle front axle load and the first front brake force generated by the vehicle front axle due to vehicle coasting energy recovery, and comprises: A first factor is determined according to the reference value of the vehicle front axle load, the first factor being the reference value of the vehicle front axle load or a modified value of the reference value of the vehicle front axle load. A second factor is determined according to the first front brake force generated by the vehicle front axle due to vehicle coasting energy recovery, the second factor being the first front brake force or a modified value of the first front brake force. The theoretical value of the vehicle front axle braking energy recovery capability is determined according to the first factor and the second factor.

[0010] According to the technical scheme provided by the embodiment of the application, optionally, the first factor is a modified value of the reference value of the vehicle front axle load, and the determination of the first factor according to the reference value of the vehicle front axle load comprises: An axle load correction coefficient is determined according to the adhesion coefficient of the current road surface, wherein the axle load correction coefficient is positively correlated with the adhesion coefficient of the current road surface, and the axle load correction coefficient is smaller than the adhesion coefficient of the current road surface. The product of the reference value of the vehicle front axle load and the axle load correction coefficient is determined as the modified value of the reference value of the vehicle front axle load. The second factor is a correction value of the first front braking force, and the second factor is determined according to the first front braking force generated by the front axle of the vehicle due to the regenerative braking of the vehicle. A regenerative braking correction coefficient of the front axle of the vehicle is determined according to the first front braking force and the first rear braking force; A product of the regenerative braking correction coefficient of the front axle of the vehicle and the first front braking force is determined as the correction value of the first front braking force.

[0011] According to the technical scheme provided by the embodiment of the application, optionally, the upper limit value of the front axle regenerative braking capacity of the vehicle and the upper limit value of the rear axle regenerative braking capacity of the vehicle are determined according to the reference value of the vehicle regenerative braking capacity output by the vehicle controller, the theoretical value of the front axle regenerative braking capacity of the vehicle and the theoretical value of the rear axle regenerative braking capacity of the vehicle, and the technical scheme comprises the following steps: The sum of the theoretical value of the front axle regenerative braking capacity of the vehicle and the theoretical value of the rear axle regenerative braking capacity of the vehicle is calculated; If the reference value of the vehicle regenerative braking capacity output by the vehicle controller is greater than the sum, the upper limit value of the front axle regenerative braking capacity of the vehicle is equal to the theoretical value of the front axle regenerative braking capacity of the vehicle, and the upper limit value of the rear axle regenerative braking capacity of the vehicle is equal to the theoretical value of the rear axle regenerative braking capacity of the vehicle; If the reference value of the vehicle regenerative braking capacity output by the vehicle controller is less than the sum, the upper limit value of the front axle regenerative braking capacity of the vehicle and the upper limit value of the rear axle regenerative braking capacity of the vehicle are determined according to the reference value of the vehicle regenerative braking capacity output by the vehicle controller.

[0012] According to the technical scheme provided by the embodiment of the application, optionally, the upper limit value of the front axle regenerative braking capacity of the vehicle and the upper limit value of the rear axle regenerative braking capacity of the vehicle are determined according to the reference value of the vehicle regenerative braking capacity output by the vehicle controller, the theoretical value of the front axle regenerative braking capacity of the vehicle and the theoretical value of the rear axle regenerative braking capacity of the vehicle, and the technical scheme comprises the following steps: The ratio of the theoretical value of the front axle regenerative braking capacity of the vehicle to the sum is calculated; The product of the ratio and the reference value of the vehicle regenerative braking capacity output by the vehicle controller is determined as the upper limit value of the front axle regenerative braking capacity of the vehicle; The difference between the reference value of the vehicle regenerative braking capacity output by the vehicle controller and the upper limit value of the front axle regenerative braking capacity of the vehicle is determined as the upper limit value of the rear axle regenerative braking capacity of the vehicle.

[0013] In a second aspect, the embodiments of the present application further provide a brake energy recovery capability determination system, comprising: a vehicle controller, a brake controller, a motor controller, a brake system, a motor, a battery and a wheel system; The vehicle controller is configured to output a reference value of a vehicle brake energy recovery capability. The brake controller is configured to determine an upper limit value of a front axle brake energy recovery capability of the vehicle and an upper limit value of a rear axle brake energy recovery capability of the vehicle according to the brake energy recovery capability determination method of the first aspect, and send a brake request to the motor controller and the brake system according to the upper limit values and a brake demand input by a driver; the brake system outputs a brake torque to the wheel system according to the brake request. The motor controller sends a corresponding torque request to the motor according to the brake request, and the motor outputs a brake force to the wheel system according to the torque request and sends recovered electric energy to the battery.

[0014] In a third aspect, the embodiments of the present application further provide an electronic device, which comprises: a processor and a memory; The processor is configured to execute the steps of the brake energy recovery capability determination method according to any one of the embodiments by calling programs or instructions stored in the memory.

[0015] In a fourth aspect, the embodiments of the present application further provide a computer readable storage medium storing programs or instructions, which cause a computer to execute the steps of the brake energy recovery capability determination method according to any one of the embodiments.

[0016] In summary, the present application provides a brake energy recovery capability determination method, which aims to provide upper limit values of brake energy recovery capability under the premise of ensuring brake safety, so as to maximize brake energy recovery efficiency. Specifically, a theoretical value of a front axle brake energy recovery capability of a vehicle is determined according to a dynamic detection value of a front axle load of the vehicle, a first front brake force generated by the front axle of the vehicle due to vehicle coasting energy recovery and an axle load shift amount; a theoretical value of a rear axle brake energy recovery capability of the vehicle is determined according to a dynamic detection value of a rear axle load of the vehicle, a first rear brake force generated by the rear axle of the vehicle due to vehicle coasting energy recovery and the axle load shift amount (as the axle load shift amount is considered, the determined theoretical value of the brake energy recovery capability is closer to the actual value and more accurate, and finally the rationality and accuracy of the upper limit value of the brake energy recovery capability are improved, which provides a premise for maximizing brake energy recovery efficiency); an upper limit value of the front axle brake energy recovery capability of the vehicle and an upper limit value of the rear axle brake energy recovery capability of the vehicle are determined according to a reference value of a vehicle brake energy recovery capability output by a vehicle controller, the theoretical value of the front axle brake energy recovery capability of the vehicle and the theoretical value of the rear axle brake energy recovery capability of the vehicle. Attached Figure Description

[0017] Figure 1 This is a flowchart of a method for determining braking energy recovery capability provided in an embodiment of this application; Figure 2 This is a schematic diagram of a braking energy recovery capability determination system provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0018] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] Figure 1 This is a flowchart illustrating a method for determining regenerative braking capacity according to an embodiment of this application. This method can be executed by a regenerative braking capacity determining device, which can be implemented in software and / or hardware and integrated into the brake controller.

[0021] See Figure 1 The method for determining the regenerative braking capacity specifically includes the following steps: S110. Determine the axle load transfer amount based on the vehicle's driving information.

[0022] Axle load transfer refers to the change in axle load distribution relative to steady-state driving conditions caused by a shift in the center of gravity of a vehicle under non-steady-state driving conditions (such as acceleration, braking, hill starts, and steering). Simply put, while the total mass of a vehicle is fixed, different driving conditions cause the total mass to shift between axles; the magnitude of this shifted mass is the axle load transfer.

[0023] Vehicle driving information includes, but is not limited to: the vehicle's total mass, center of gravity height, wheelbase, longitudinal deceleration, and other information that affects axle load transfer.

[0024] In some implementations, determining the axle load transfer amount based on the vehicle's driving information includes: inputting the vehicle's driving information into a trained axle load transfer model, and outputting the axle load transfer amount through the axle load transfer model.

[0025] In other embodiments, determining the axle load transfer amount based on the vehicle's driving information includes: determining a matching axle load transfer amount from a first preset relationship based on the driving information, wherein the first preset relationship is a correspondence between driving information and axle load transfer amount, and the correspondence can be obtained through experimental calibration.

[0026] In other embodiments, taking vehicle driving information including the vehicle's total mass, center of gravity height, wheelbase, and longitudinal deceleration as an example, the axle load transfer is determined based on the vehicle's driving information, including: The axle load transfer amount is determined by the following formula:

[0027] In the formula, This is the amount of axle load transfer. For the height of the center of mass, This refers to the vehicle's wheelbase. The magnitude of the vehicle's longitudinal deceleration. For the overall vehicle weight.

[0028] S120. Determine the theoretical value of the vehicle's front axle braking energy recovery capability based on the dynamic detection value of the vehicle's front axle load, the first front braking force generated by the vehicle's front axle due to the recovery of vehicle coasting energy, and the amount of axle load transfer; and determine the theoretical value of the vehicle's rear axle braking energy recovery capability based on the dynamic detection value of the vehicle's rear axle load, the first rear braking force generated by the vehicle's rear axle due to the recovery of vehicle coasting energy, and the amount of axle load transfer.

[0029] The dynamic detection value of the front axle load of a vehicle can be achieved through dynamic weighing technology. Unlike static weighing, dynamic weighing needs to overcome the interference effects of impact, vibration, and speed fluctuations caused by vehicle movement. Therefore, it requires algorithmic compensation for dynamic errors. Specifically, strain sensors installed on the suspension system or steering knuckle of the front axle can capture dynamic pressure signals during vehicle movement. Combined with information such as vehicle speed, the dynamic pressure signals are corrected by an algorithm to obtain the dynamic detection value. The process of correcting the dynamic pressure signal is as follows: a correction model based on vehicle speed is established. The detection values ​​at different vehicle speeds need to be compensated according to the model. Generally, the higher the vehicle speed, the greater the impact load. Therefore, the detection value needs to be reduced by a certain amount according to the vehicle speed to deduct the impact component. Other existing detection methods can also be used. This embodiment does not limit the detection method for the dynamic detection value of the front axle load of a vehicle.

[0030] Coasting refers to the state in which a vehicle moves forward due to inertia without active acceleration or braking. Currently, for new energy vehicles, when a vehicle enters a coasting state, it automatically enters energy recovery mode, and mechanical braking usually does not intervene. Therefore, the braking force on the vehicle comes entirely from the braking force generated by energy recovery. In coasting energy recovery mode, the drive motor switches to a generator, and the wheels drive the motor rotor to rotate and generate electricity. The counter-draft torque generated by the motor is transmitted to the wheels through the transmission system, forming a braking force that resists the vehicle's forward movement.

[0031] The initial braking force generated by the vehicle's front axle due to regenerative braking can be determined as follows: The braking force can be calculated using the vehicle's deceleration during coasting. Alternatively, the regenerative braking torque of the electric motor can be calculated first. This torque is transmitted to the wheels via a reducer and driveshaft. Based on the transmission ratio and mechanical efficiency, the regenerative braking torque can be converted into wheel-end regenerative torque. The ground braking force can then be calculated based on this wheel-end regenerative torque. Multiplying this by the front axle torque distribution coefficient gives the initial front braking force generated by the vehicle's coasting energy recovery. Alternatively, the initial front braking force generated by the vehicle's coasting energy recovery can be determined using the following formula:

[0032] in, This indicates the initial braking force generated on the front axle due to energy recovery during vehicle coasting. This indicates the magnitude of the regenerative torque of the motor on the front axle. This indicates the radius of the wheel / tire.

[0033] The method for determining the first rear braking force generated by the vehicle's coasting energy recovery on the rear axle is similar to the method for determining the first front braking force generated by the vehicle's coasting energy recovery on the front axle, and will not be repeated here.

[0034] In general, the vehicle's front axle is further subdivided into the left front axle and the right front axle, and the corresponding dynamic detection values ​​of the axle load include the dynamic detection values ​​of the left front axle load and the right front axle load. The theoretical value for determining the vehicle's front axle braking energy recovery capability based on the dynamic detection values ​​of the vehicle's front axle load, the first front braking force generated by the vehicle's front axle due to coasting energy recovery, and the axle load transfer amount includes: Determine the sum of the dynamic detection values ​​of the left front axle load and the right front axle load; determine the reference value of the vehicle's front axle load based on the sum of the dynamic detection values ​​and the axle load transfer amount; and determine the theoretical value of the vehicle's front axle braking energy recovery capability based on the reference value of the vehicle's front axle load and the first front braking force generated by the vehicle's front axle due to the vehicle's coasting energy recovery.

[0035] Specifically, determining a reference value for the front axle load of the vehicle based on the sum of the dynamically detected values ​​and the axle load transfer amount includes: in response to an uphill road condition, determining the difference between the sum and the axle load transfer amount as the reference value for the front axle load; in response to a downhill road condition, determining the sum of the sum and the axle load transfer amount as the reference value for the front axle load; and in response to a road slope of zero (i.e., a level surface), determining the sum as the reference value for the front axle load.

[0036] Understandably, when the current road condition is uphill, the vehicle's center of gravity shifts rearward, thus increasing the axle load on the rear axle and decreasing the axle load on the front axle. Therefore, in response to the current road condition being uphill, the difference between the sum of the measured values ​​and the axle load transfer is determined as the reference value for the front axle load. When the current road condition is downhill, the vehicle's center of gravity shifts forward, thus increasing the axle load on the front axle and decreasing the axle load on the rear axle. Therefore, in response to the current road condition being downhill, the sum of the measured values ​​and the axle load transfer is determined as the reference value for the front axle load. When the current road condition is level, the vehicle's center of gravity does not shift. Therefore, in response to the current road condition having a zero gradient, the sum of the dynamically detected values ​​of the left and right front axle loads is determined as the reference value for the front axle load.

[0037] Furthermore, determining the theoretical value of the vehicle's front axle braking energy recovery capability based on the reference value of the vehicle's front axle load and the first front braking force generated by the vehicle's front axle due to coasting energy recovery includes: A first factor is determined based on a reference value of the vehicle's front axle load, where the first factor is either a reference value of the vehicle's front axle load or a correction value of the reference value of the vehicle's front axle load; a second factor is determined based on a first front braking force generated by the vehicle's front axle due to recuperation of vehicle coasting energy, where the second factor is either a correction value of the first front braking force or the first front braking force; and a theoretical value of the vehicle's front axle braking energy recovery capability is determined based on the first factor and the second factor.

[0038] In some implementations, the theoretical value of the vehicle's front axle regenerative braking capacity is determined based on a reference value of the vehicle's front axle load and the first front braking force. Specifically, the difference between the reference value of the vehicle's front axle load and the first front braking force is determined as the theoretical value of the vehicle's front axle regenerative braking capacity.

[0039] In some implementations, the theoretical value of the vehicle's front axle regenerative braking capacity is determined based on a reference value of the vehicle's front axle load and a correction value for the first front braking force. Specifically, the difference between the reference value of the vehicle's front axle load and the correction value for the first front braking force is determined as the theoretical value of the vehicle's front axle regenerative braking capacity.

[0040] In some implementations, the theoretical value of the vehicle's front axle regenerative braking capacity is determined based on a correction value of the reference value of the vehicle's front axle load and the first front braking force. Specifically, the difference between the correction value of the reference value of the vehicle's front axle load and the first front braking force is determined as the theoretical value of the vehicle's front axle regenerative braking capacity.

[0041] In some implementations, the theoretical value of the vehicle's front axle regenerative braking capacity is determined based on a correction value for a reference value of the vehicle's front axle load and a correction value for the first front braking force. Specifically, the difference between the correction value for the reference value of the vehicle's front axle load and the correction value for the first front braking force is determined as the theoretical value of the vehicle's front axle regenerative braking capacity.

[0042] The difference between the above-described implementation methods for determining the theoretical value of the vehicle's front axle braking energy recovery capability lies in their accuracy. The theoretical value of the vehicle's front axle braking energy recovery capability determined using the correction value of the reference value of the vehicle's front axle load and the correction value of the first front braking force has the highest accuracy. This is because the correction value of the reference value of the vehicle's front axle load is more accurate than the reference value itself. Therefore, the theoretical value of the vehicle's front axle braking energy recovery capability determined using the correction value of the reference value of the vehicle's front axle load is more accurate than the theoretical value determined using the reference value of the vehicle's front axle load. Similarly, the correction value of the first front braking force is more accurate than the first front braking force itself. Therefore, the theoretical value of the vehicle's front axle braking energy recovery capability determined using the correction value of the first front braking force is more accurate than the theoretical value determined using the first front braking force. Thus, the theoretical value of the vehicle's front axle braking energy recovery capability determined using the correction value of the reference value of the vehicle's front axle load and the correction value of the first front braking force has the highest accuracy.

[0043] Furthermore, when the first factor is a correction value of the reference value of the vehicle's front axle load, determining the first factor based on the reference value of the vehicle's front axle load includes: The axle load correction factor is determined based on the current road surface adhesion coefficient, wherein the axle load correction factor is positively correlated with the current road surface adhesion coefficient and is less than the current road surface adhesion coefficient; the product of the reference value of the vehicle's front axle load and the axle load correction factor is determined as the correction value of the reference value of the vehicle's front axle load.

[0044] When the second factor is a correction value for the first front braking force, determining the second factor based on the first front braking force generated by the vehicle's front axle due to vehicle coasting energy recovery includes: The coasting energy recovery correction coefficient of the vehicle's front axle is determined based on the first front braking force and the first rear braking force; wherein, when the first front braking force is less than or equal to the first rear braking force, the coasting energy recovery correction coefficient of the vehicle's front axle is less than the coasting energy recovery correction coefficient of the vehicle's front axle.

[0045] The product of the coasting energy recovery correction coefficient of the vehicle's front axle and the first front braking force is determined as the correction value of the first front braking force.

[0046] The method for determining the theoretical value of the vehicle's front axle braking energy recovery capability is the same as that for determining the theoretical value of the vehicle's rear axle braking energy recovery capability. Therefore, this embodiment will not elaborate on the method for determining the theoretical value of the vehicle's rear axle braking energy recovery capability.

[0047] To facilitate a more intuitive understanding of the process for determining the theoretical values, the process is expressed by the following formula:

[0048]

[0049] in, This represents the theoretical value of the vehicle's front axle braking energy recovery capability. This represents the theoretical value of the vehicle's rear axle braking energy recovery capability. This represents the dynamic measured value of the left front axle load. This represents the dynamic measured value of the right front axle load. This represents the dynamic measured value of the left rear axle load. This represents the dynamic measured value of the right rear axle load. Indicates the axle load correction factor. This indicates the initial braking force generated on the front axle due to energy recovery during vehicle coasting. This indicates the first rear braking force generated on the rear axle due to energy recovery during vehicle coasting. This represents the correction factor for coasting energy recovery on the front axle of the vehicle. This represents the correction factor for coasting energy recovery on the rear axle of the vehicle. This represents the amount of axle load transfer.

[0050] Furthermore, determining the axle load correction factor based on the current road surface adhesion coefficient includes using the current road surface adhesion coefficient as a query field to find the corresponding axle load correction factor from a predefined relationship. The predefined relationship can be determined through experimental calibration or through manual experience. An example is shown in Table 1, illustrating one such predefined relationship.

[0051] Table 1

[0052] The purpose of correcting the reference value of the front axle load using the axle load correction factor is to further improve the accuracy and rationality of the reference value. This can be understood from the following aspects: the axle load correction factor is essentially the "effective utilization factor" of the axle load, representing the proportion of axle load that can actually be converted into effective braking force under the current road adhesion conditions. By correcting the reference value of the front axle load using the axle load correction factor, the results can be made more consistent with the actual scenario, avoiding the braking energy recovery capacity calculated solely using axle load from exceeding the ground adhesion limit (for example, the adhesion coefficient μ on a wet and slippery road surface is small, so even if the axle load is large, the actual braking force provided is limited), making the calculation results more consistent with the physical constraints of actual vehicle braking.

[0053] Furthermore, determining the coasting energy recovery correction coefficient of the vehicle's front axle based on the first front braking force and the first rear braking force includes: Calculate the ratio of the first front braking force to the first rear braking force; use the ratio as a query field to find the matching vehicle front axle coasting energy recovery correction coefficient from the second preset relationship.

[0054] The step of determining the coasting energy recovery correction coefficient of the vehicle's rear axle based on the first front braking force and the first rear braking force includes: using the ratio as a query field to search for a matching coasting energy recovery correction coefficient of the vehicle's rear axle from a third preset relationship. The second and third preset relationships can be obtained through experimental calibration or set manually based on experience.

[0055] As shown in Tables 2 and 3, there are schematic diagrams of a second preset relationship and a third preset relationship.

[0056] Table 2

[0057] Table 3

[0058] In general, when the first front braking force is less than or equal to the first rear braking force, the coasting energy recovery correction coefficient of the vehicle's front axle is less than the coasting energy recovery correction coefficient of the vehicle's front axle. The advantage of using the coasting energy recovery correction coefficient to correct the first front and first rear braking forces, and setting the coasting energy recovery correction coefficient according to Tables 2 and 3 above, is that it adapts to the actual constraints of the front and rear axle braking force distribution ratio on energy recovery. Specifically, during vehicle braking, the front and rear axle braking forces need to be distributed in a reasonable ratio to avoid single-axle lock-up. The aforementioned ratio λ represents the actual ratio of the front and rear axle coasting regenerative braking forces. Determining the appropriate correction coefficient through this ratio ensures that the theoretical value of the final braking energy recovery capacity conforms to the actual braking force distribution logic of the vehicle, avoiding the recovery capacity of one axle from exceeding the upper limit of safe braking distribution, while balancing energy recovery efficiency and braking safety. If the recovery capacity is calculated only based on axle load, there may be a risk of excessive single-axle regenerative braking force leading to lock-up. The correction coefficient, by correcting the front and rear axle recovery forces, ensures that energy is recovered as much as possible while ensuring that the front and rear axle braking force distribution is within a safe range. When a vehicle brakes, the braking force between the front and rear axles must meet the ideal braking force distribution curve (the purpose is to avoid the front wheels locking up first or the rear wheels locking up first), and the ratio λ is the actual distribution ratio of regenerative braking force, with a correction factor β (including...) β 1. β 2) This refers to the safety adaptation coefficient for this ratio. When the ratio λ is 0, the correction coefficient β is zero, meaning there is no correction, corresponding to the scenario where the rear axle is retracted alone. When the ratio λ is 0.5, meaning the front axle's retraction capability is 0.5 times that of the rear axle, then... β 1=1, β 2=2, meaning the rear axle retraction capability is amplified to match the safety constraints under this allocation ratio. When the ratio λ is 0 / 1, the front axle retraction capability is the same as the rear axle. β 1=1, β β = 1.5, fine-tuning the rear axle regenerative braking capacity to adapt to braking stability under this distribution ratio. In short, the correction factor β is an adjustment coefficient between the front and rear axle braking force distribution ratio and the energy recovery capacity, ensuring that energy recovery is both efficient and meets the physical constraints of braking safety.

[0059] S130. Based on the reference value of the vehicle's regenerative braking capacity output by the vehicle controller, the theoretical value of the vehicle's front axle regenerative braking capacity, and the theoretical value of the vehicle's rear axle regenerative braking capacity, determine the upper limit of the vehicle's front axle regenerative braking capacity and the upper limit of the vehicle's rear axle regenerative braking capacity.

[0060] The reference value for the vehicle's regenerative braking capacity output by the vehicle controller is determined by the vehicle controller based on the maximum torque capability fed back from the motor, i.e., the maximum regenerative braking capacity that the motor itself can provide. Specifically, the reference value for the vehicle's regenerative braking capacity can be determined using the maximum torque that the motor can output and the wheel tire radius.

[0061] in, A reference value indicating the vehicle's regenerative braking capability. This indicates the maximum torque that the motor can output. This indicates the radius of the wheel / tire.

[0062] In some implementations, the upper limit values ​​of the vehicle's front axle braking energy recovery capability and the vehicle's rear axle braking energy recovery capability are determined based on a reference value of the vehicle's braking energy recovery capability output by the vehicle controller, the theoretical value of the vehicle's front axle braking energy recovery capability, and the theoretical value of the vehicle's rear axle braking energy recovery capability, including: Calculate the sum of the theoretical values ​​of the vehicle's front axle braking energy recovery capacity and the vehicle's rear axle braking energy recovery capacity; if the reference value of the vehicle's braking energy recovery capacity output by the vehicle controller is greater than the sum, then determine that the upper limit of the vehicle's front axle braking energy recovery capacity is equal to the theoretical value of the vehicle's front axle braking energy recovery capacity, and the upper limit of the vehicle's rear axle braking energy recovery capacity is equal to the theoretical value of the vehicle's rear axle braking energy recovery capacity. If the reference value of the vehicle's regenerative braking capacity output by the vehicle controller is less than the sum of the theoretical values, the upper limits of the regenerative braking capacity of the front axle and the rear axle are determined based on the reference value. That is, the smaller of the sum of the theoretical values ​​of the front axle and rear axle regenerative braking capacity and the reference value is taken to ensure braking safety, avoid exceeding the motor's maximum regenerative braking capacity, and maximize regenerative braking efficiency.

[0063] Furthermore, determining the upper limit of the vehicle's front axle braking energy recovery capability and the upper limit of the vehicle's rear axle braking energy recovery capability based on the reference value of the vehicle's braking energy recovery capability output by the vehicle controller includes: Calculate the ratio of the theoretical value of the vehicle's front axle regenerative braking capacity to the sum; determine the upper limit of the vehicle's front axle regenerative braking capacity by multiplying the ratio by the reference value of the vehicle's regenerative braking capacity output by the vehicle controller; determine the upper limit of the vehicle's rear axle regenerative braking capacity by the difference between the reference value of the vehicle's regenerative braking capacity output by the vehicle controller and the upper limit of the vehicle's front axle regenerative braking capacity.

[0064] Specifically, the ratio of the theoretical value of the vehicle's front axle braking energy recovery capacity to the sum of the given values ​​is determined according to the following formula:

[0065] Will The upper limit of the vehicle's front axle braking energy recovery capacity is determined. (1- This is determined as the upper limit of the vehicle's rear axle braking energy recovery capability.

[0066] In some implementations, the method further includes sending a braking request based on the current braking demand of the driver, the upper limit of the vehicle's front axle braking energy recovery capability, and the upper limit of the vehicle's rear axle braking energy recovery capability.

[0067] The braking energy recovery capability determination method provided in this application calculates the maximum theoretical recovery limit of the vehicle during braking energy recovery by integrating axle load detection value, axle load transfer amount, and coasting energy recovery status. This avoids safety risks caused by requesting braking force exceeding the vehicle's dynamic capabilities during braking energy recovery, while maximizing the use of current braking energy recovery capability, improving recovery efficiency, and enhancing vehicle range.

[0068] Based on the same inventive concept, corresponding to any of the above embodiments, this application also provides a braking energy recovery capability determination system.

[0069] refer to Figure 2 The braking energy recovery capability determination system includes: a vehicle controller 210, a brake controller 220, a motor controller 230, a braking system 240, a motor 250, a battery 260, and a wheel system 270. Among them, the vehicle controller 210 is used to output a reference value for the vehicle's braking energy recovery capability; The brake controller 220 is used to execute the brake energy recovery capability determination method described in the above embodiments to determine the upper limit value of the brake energy recovery capability of the front axle of the vehicle and the upper limit value of the brake energy recovery capability of the rear axle of the vehicle, and to send a braking request to the motor controller 230 and the brake system 240 according to the upper limit value and the braking demand input by the driver; the brake system 240 outputs braking torque to the wheel system 270 according to the braking request; the motor controller 230 sends a corresponding torque request to the motor 250 according to the braking request, and the motor 250 outputs braking force to the wheel system 270 according to the torque request, and sends the recovered electrical energy to the battery 260.

[0070] Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. For example... Figure 3 As shown, the electronic device 500 includes one or more processors 501 and memory 502.

[0071] The processor 501 may be a central processing unit (CPU) or other form of processing unit with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device 500 to perform desired functions.

[0072] The memory 502 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 501 may execute the program instructions to implement the braking energy recovery capability determination method of any embodiment of this application described above and / or other desired functions. Various contents such as initial external parameters and thresholds may also be stored in the computer-readable storage medium.

[0073] In one example, the electronic device 500 may further include an input device 503 and an output device 504, these components being interconnected via a bus system and / or other forms of connection mechanisms (not shown). The input device 503 may include, for example, a keyboard, a mouse, etc. The output device 504 may output various information to the outside, including warning messages, braking force, etc. The output device 504 may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, etc.

[0074] Of course, for the sake of simplicity, Figure 3Only some of the components of the electronic device 500 relevant to this application are shown in this illustration; components such as buses, input / output interfaces, etc., are omitted. In addition, the electronic device 500 may include any other suitable components depending on the specific application.

[0075] In addition to the methods and devices described above, embodiments of this application may also be computer program products, which include computer program instructions that, when executed by a processor, cause the processor to perform the steps of the braking energy recovery capability determination method provided in any embodiment of this application.

[0076] The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of this application. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0077] Furthermore, embodiments of this application may also be computer-readable storage media storing computer program instructions thereon, which, when executed by a processor, cause the processor to perform the steps of the braking energy recovery capability determination method provided in any embodiment of this application.

[0078] The computer-readable storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0079] It should be noted that the terminology used in this application is for the purpose of describing specific embodiments only and is not intended to limit the scope of this application. As shown in the specification and claims of this application, unless the context clearly indicates otherwise, words such as "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. The terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, or apparatus. Without further limitations, an element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element.

[0080] It should also be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," "linked," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0081] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A method for determining braking energy recovery capability, characterized in that, include: Determine the axle load transfer amount based on the vehicle's driving information; The theoretical value of the vehicle's front axle braking energy recovery capability is determined based on the dynamic detection value of the vehicle's front axle load, the first front braking force generated by the vehicle's front axle due to the recovery of energy during vehicle coasting, and the amount of axle load transfer. And the theoretical value of the vehicle's rear axle braking energy recovery capability is determined based on the dynamic detection value of the vehicle's rear axle load, the first rear braking force generated by the vehicle's rear axle due to the recovery of energy during vehicle coasting, and the amount of axle load transfer. Based on the reference value of the vehicle's regenerative braking capacity output by the vehicle controller, the theoretical value of the vehicle's front axle regenerative braking capacity, and the theoretical value of the vehicle's rear axle regenerative braking capacity, the upper limit of the vehicle's front axle regenerative braking capacity and the upper limit of the vehicle's rear axle regenerative braking capacity are determined.

2. The method for determining braking energy recovery capability according to claim 1, characterized in that, Determining the axle load transfer amount based on the vehicle's driving information includes: The driving information is input into the axle load transfer model to obtain the axle load transfer amount; Alternatively, based on the driving information, a matching axle load transfer amount can be determined from a first preset relationship, where the first preset relationship is the correspondence between driving information and axle load transfer amount.

3. The method for determining braking energy recovery capability according to claim 1, characterized in that, The vehicle's front axle includes a left front axle and a right front axle, and the corresponding dynamic detection values ​​of the axle load include the dynamic detection values ​​of the left front axle load and the dynamic detection values ​​of the right front axle load. The theoretical value for determining the vehicle's front axle braking energy recovery capability based on the dynamic detection value of the vehicle's front axle load, the first front braking force generated by the vehicle's front axle due to recuperation of vehicle coasting energy, and the axle load transfer amount includes: Determine the sum of the dynamic measured values ​​of the left front axle load and the right front axle load; Based on the sum of the dynamic detection values ​​and the axle load transfer amount, a reference value for the front axle load of the vehicle is determined; The theoretical value of the vehicle's front axle braking energy recovery capability is determined based on the reference value of the vehicle's front axle load and the first front braking force generated by the vehicle's front axle due to the recovery of energy during vehicle coasting.

4. The method for determining braking energy recovery capability according to claim 3, characterized in that, The theoretical value for determining the vehicle's front axle braking energy recovery capability based on the reference value of the vehicle's front axle load and the first front braking force generated by the vehicle's front axle due to coasting energy recovery includes: A first factor is determined based on the reference value of the vehicle's front axle load, wherein the first factor is either the reference value of the vehicle's front axle load or a correction value of the reference value of the vehicle's front axle load. The second factor is determined based on the first front braking force generated by the vehicle's front axle due to the recovery of energy during vehicle coasting. The second factor is a correction value for the first front braking force or the first front braking force. The theoretical value of the vehicle's front axle braking energy recovery capability is determined based on the first factor and the second factor.

5. The method for determining braking energy recovery capability according to claim 4, characterized in that, The first factor is a correction value to a reference value of the vehicle's front axle load. Determining the first factor based on the reference value of the vehicle's front axle load includes: The axle load correction factor is determined based on the current road surface adhesion coefficient, wherein the axle load correction factor is positively correlated with the current road surface adhesion coefficient, and the axle load correction factor is less than the current road surface adhesion coefficient. The product of the reference value of the front axle load of the vehicle and the axle load correction factor is determined as the correction value of the reference value of the front axle load of the vehicle.

6. The method for determining braking energy recovery capability according to claim 4, characterized in that, The second factor is a correction value for the first front braking force. Determining the second factor based on the first front braking force generated by the vehicle's front axle due to vehicle coasting energy recovery includes: The correction coefficient for recuperation of the vehicle's front axle is determined based on the first front braking force and the first rear braking force. The product of the coasting energy recovery correction coefficient of the vehicle's front axle and the first front braking force is determined as the correction value of the first front braking force.

7. The method for determining braking energy recovery capability according to claim 1, characterized in that, The determination of the upper limit values ​​of the vehicle's front axle braking energy recovery capacity and the vehicle's rear axle braking energy recovery capacity based on the reference value of the vehicle's braking energy recovery capacity output by the vehicle controller, the theoretical value of the vehicle's front axle braking energy recovery capacity, and the theoretical value of the vehicle's rear axle braking energy recovery capacity includes: Calculate the theoretical value of the vehicle's front axle brake energy recovery capacity and the sum of the theoretical values ​​of the vehicle's rear axle brake energy recovery capacity; If the reference value of the vehicle's regenerative braking capacity output by the vehicle controller is greater than the sum of the two values, then the upper limit of the vehicle's front axle regenerative braking capacity is determined to be equal to the theoretical value of the vehicle's front axle regenerative braking capacity, and the upper limit of the vehicle's rear axle regenerative braking capacity is determined to be equal to the theoretical value of the vehicle's rear axle regenerative braking capacity. If the reference value of the vehicle's regenerative braking capacity output by the vehicle controller is less than the sum of the values, the upper limit of the vehicle's front axle regenerative braking capacity and the upper limit of the vehicle's rear axle regenerative braking capacity are determined based on the reference value of the vehicle's regenerative braking capacity output by the vehicle controller.

8. The method for determining braking energy recovery capability according to claim 7, characterized in that, The step of determining the upper limit of the vehicle's front axle braking energy recovery capability and the upper limit of the vehicle's rear axle braking energy recovery capability based on the reference value of the vehicle's braking energy recovery capability output by the vehicle controller includes: Calculate the ratio of the theoretical value of the vehicle's front axle braking energy recovery capacity to the sum of the values. The product of the ratio and the reference value of the vehicle's regenerative braking capacity output by the vehicle controller is determined as the upper limit of the vehicle's front axle regenerative braking capacity. The difference between the reference value of the vehicle's regenerative braking capacity output by the vehicle controller and the upper limit of the vehicle's front axle regenerative braking capacity is determined as the upper limit of the vehicle's rear axle regenerative braking capacity.

9. A system for determining braking energy recovery capability, characterized in that, include: Vehicle controller, brake controller, motor controller, braking system, motor, battery, and wheel system; Among them, the vehicle controller is used to output a reference value for the vehicle's regenerative braking capability; The brake controller is used to determine the upper limit of the braking energy recovery capacity of the front axle of the vehicle and the upper limit of the braking energy recovery capacity of the rear axle of the vehicle according to the braking energy recovery capacity determination method according to any one of claims 1-8, and to send a braking request to the motor controller and the braking system according to the upper limit and the braking demand input by the driver. The braking system outputs braking torque to the wheel system according to the braking request; The motor controller sends a corresponding torque request to the motor based on the braking request. The motor then outputs braking force to the wheel system and sends the recovered electrical energy to the battery based on the torque request.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a program or instructions that cause a computer to perform the steps of the braking energy recovery capability determination method as described in any one of claims 1 to 8.

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