A brake force distribution method and system based on a distributed brake drive control architecture

Abstract

This application discloses a braking force distribution method and system based on a distributed braking drive control architecture, relating to the field of vehicle braking technology. A coordination controller acquires the total braking torque demand of the entire vehicle and distributes it to each wheel according to an ideal braking force distribution strategy, obtaining the initial target wheel-end total torque for each wheel and sending it to the wheel-end nodes of each wheel. Each wheel-end node performs regenerative priority allocation of the initial target wheel-end total torque based on the upper limit of its current regenerative braking torque and the upper limit of its EMB friction braking torque, determining the actual achievable torque and the deficit residual, and reporting it to the coordination controller. The coordination controller performs secondary torque allocation based on the actual achievable torque and deficit residual of each wheel, generating the final wheel-end target total torque for each wheel and sending it to the wheel-end nodes of each wheel. This application considers the differences in wheel-end capabilities in real time through closed-loop interaction, enabling the deficit residual to be recoupled at the vehicle level, improving braking response consistency and braking force distribution adaptability.

Description

Technical Field

[0001] This application relates to the field of vehicle braking technology, and more specifically, to a braking force distribution method and system based on a distributed braking drive control architecture. Background Technology

[0002] With the development of new energy vehicle technology, in-wheel motor distributed drive has become an important direction. Meanwhile, electromechanical brakes (EMBs), which are easy to control in a distributed manner, are gradually replacing traditional hydraulic braking systems. In an architecture that integrates distributed drive and distributed braking, each wheel-end drive and brake actuator can be controlled independently, providing a hardware foundation for precise coordination of braking force.

[0003] However, existing technologies for coordinated control of hub motor and EMB combined braking typically employ an open-loop allocation scheme with segmented decision-making, regeneration priority, and EMB supplementation for insufficient braking, lacking a closed-loop dynamic feedback and redistribution mechanism. These schemes have shortcomings in a distributed architecture: frequent intervention and withdrawal of regenerative braking during low-intensity braking leads to inconsistent responses; the regeneration priority strategy affects braking linearity; and the different capabilities of each wheel-end node necessitate a lack of a unified secondary allocation coordination mechanism. Summary of the Invention

[0004] The purpose of this application is to provide a braking force distribution method and system based on a distributed braking drive control architecture, which solves the problem in the prior art that the torque distribution of vehicles with combined braking of hub motor and EMB cannot fully consider the real-time capability differences of each wheel end node and the lack of braking force due to insufficient capability of a single wheel, so as to achieve reasonable coordinated control between hub motor and EMB under different braking intensity conditions.

[0005] In a first aspect, the technical solution of this application provides a braking force distribution method based on a distributed braking drive control architecture, characterized in that it is applied to a coordination controller, and the method includes: Obtain the total braking torque requirement of the entire vehicle; According to the ideal braking force distribution strategy, the total braking torque demand of the whole vehicle is distributed to each wheel to obtain the initial target wheel end total torque of each wheel and then sent to the wheel end node of each wheel. The actual achievable torque and the shortfall residual reported by each wheel-end node are obtained; the actual achievable torque and the shortfall residual are obtained by regenerative priority allocation of the initial target wheel-end total torque based on the upper limit of regenerative braking torque and the upper limit of EMB friction braking torque. Based on the actual achievable torque and residual deficit of each wheel, a secondary torque distribution is performed to generate the final target total torque at the wheel end of each wheel and distribute it to the wheel end node of each wheel.

[0006] In some solutions, the braking force distribution method based on a distributed braking drive control architecture includes obtaining the total braking torque requirement of the vehicle, which includes: Obtain the vehicle's actual speed and target speed; Based on the deviation between the actual vehicle speed and the target vehicle speed, a proportional-integral controller combined with a feedforward braking torque term is used to calculate the total braking torque requirement of the vehicle.

[0007] Some solutions describe a braking force distribution method based on a distributed braking drive control architecture, which calculates the total braking torque requirement of the vehicle in the following way: ; in, For the total braking torque requirement of the entire vehicle, It is a saturation function. This is the proportionality coefficient. This refers to the deviation between the actual vehicle speed and the target vehicle speed. The integral coefficient is... This is the feedforward braking torque term. This is the maximum braking torque of the entire vehicle.

[0008] In some schemes, the braking force distribution method based on a distributed braking drive control architecture is described, wherein the feedforward braking torque term is determined based on at least one of desired deceleration, gradient, or vehicle resistance.

[0009] Some solutions describe braking force distribution methods based on distributed braking drive control architecture, which obtain the initial target total wheel-end torque for each wheel in the following manner: Obtain the current axle load transfer amount and determine the longitudinal distribution coefficient of each wheel based on the current axle load transfer amount; The total braking torque requirement of the entire vehicle is distributed to each wheel according to the longitudinal distribution coefficient of each wheel, so as to obtain the initial target total wheel end torque of each wheel.

[0010] In some schemes, the braking force distribution method based on a distributed braking drive control architecture further includes the following steps in obtaining the initial target total wheel-end torque for each wheel: The initial target wheel-end total torque is corrected based on the yaw torque correction term. The corrected initial target wheel-end total torque is expressed as follows: ; in, Let be the initial target total wheel end torque of the i-th wheel. Let be the longitudinal distribution coefficient for the i-th wheel. For the total braking torque requirement of the entire vehicle, This is the yaw torque correction term for the i-th wheel, which is zero when there is no stability control request.

[0011] Some of the braking force distribution methods based on distributed braking drive control architecture described in the schemes perform secondary torque distribution, including: Calculate the total deficit of all wheels and the surplus capacity of each wheel; The total deficit is redistributed according to the proportion of surplus capacity of each wheel, and a yaw torque constraint is applied to the difference in compensation torque between the left and right wheels on the same axle to obtain the final target total torque at the wheel end of each wheel.

[0012] In some schemes, the braking force distribution method based on a distributed braking drive control architecture is expressed as follows: The final target total torque at the wheel end of each wheel is: ; ; ; ; ; ; in, Let be the final target total torque at the wheel end of the i-th wheel. Let be the initial target total wheel end torque of the i-th wheel. Let be the compensation torque for the i-th wheel. Let be the residual deficit of the i-th wheel. This represents the final target total torque at the wheel end of the left front wheel. This represents the final target total torque at the wheel end of the right front wheel. This represents the final target total torque at the left rear wheel end. This represents the final target total torque at the wheel end of the right rear wheel. The yaw torque threshold is the difference between the final target total torque at the wheel ends of the left and right wheels on the same axle. This represents the total shortfall. Let be the spare capacity of the i-th wheel. Let j be the spare capacity of the j-th wheel. This represents the upper limit of the regenerative braking torque for the i-th wheel. This represents the upper limit of the EMB friction braking torque for the i-th wheel.

[0013] Some of the braking force distribution methods based on distributed braking drive control architecture described in the schemes perform secondary torque distribution, including: Construct the objective function: ; in, Let represent the final target total torque at the wheel end of the i-th wheel, used as an optimization variable. Let i be the regenerative braking torque of the i-th wheel. Let be the EMB friction braking torque of the i-th wheel, and , For the first i The upper limit of regenerative braking torque per wheel; For friction braking weight, For regenerative braking weight, This is a stability penalty function; The constraints of the objective function include: Longitudinal braking force tracking constraint: The deviation between the total braking torque requirement of the vehicle and the set threshold shall not exceed. Wheel end capability limit constraints: ; For the first i The upper limit of EMB friction braking torque for each wheel; Yaw torque constraint: The difference between the final target total torque at the wheel ends of the left and right wheels on the same axle shall not exceed the yaw torque threshold. Solve the objective function to obtain the final target total torque at the wheel end of each wheel.

[0014] Secondly, the technical solution of this application provides a braking force distribution method based on a distributed braking drive control architecture, applied to wheel-end nodes, including: Receive the initial target total wheel-end torque from the coordination controller; Based on the current regenerative braking torque limit and EMB friction braking torque limit of the corresponding wheel, the initial target wheel end total torque is regenerated preferentially allocated to determine the actual achievable torque and the shortfall residual, and the actual achievable torque and the shortfall residual are reported to the coordination controller. The final target total torque at the wheel end is generated by the receiving coordination controller after secondary allocation based on the actual achievable torque and the deficit residual; Based on the final target total torque at the wheel end, the final regenerative braking torque and the final EMB friction braking torque are generated and sent to the motor controller and the EMB actuator, respectively.

[0015] Some of the braking force distribution methods based on distributed braking drive control architecture described in the schemes include the following steps in determining the actual achievable torque and the shortfall residual: The regenerative braking torque and EMB requirement torque are determined based on the upper limit of the regenerative braking torque and the initial target wheel-end total torque. When the EMB required torque exceeds the upper limit of the EMB friction braking torque, the sum of the upper limit of the regenerative braking torque and the upper limit of the EMB friction braking torque is determined as the actual achievable torque, and the difference between the initial target wheel end total torque and the actual achievable torque is determined as the deficit residual.

[0016] Some of the braking force distribution methods based on distributed braking drive control architecture described in the schemes also include the following steps in determining the actual achievable torque and the shortfall residual: When the required torque of the EMB does not exceed the upper limit of the friction braking torque of the EMB, the initial target total torque at the wheel end is determined as the actual achievable torque, and the deficit residual is zero.

[0017] Some solutions describe braking force distribution methods based on distributed braking drive control architecture, which generate the final regenerative braking torque and the final EMB friction braking torque in the following manner: ; ; in, Let be the final regenerative braking torque of the i-th wheel. Let be the final target total torque at the wheel end of the i-th wheel. This represents the upper limit of the regenerative braking torque for the i-th wheel. Let be the final EMB friction braking torque of the i-th wheel.

[0018] Some solutions describe braking force distribution methods based on distributed braking drive control architecture, which, when generating the final regenerative braking torque and the final EMB friction braking torque, superimpose the following fault degradation logic: If the regenerative braking system of the corresponding wheel fails, the upper limit of regenerative braking torque is set to zero, and a full friction braking strategy is output. If the corresponding wheel has an EMB failure, a safety mode request will be output and the target deceleration will be limited.

[0019] Thirdly, the technical solution of this application provides a coordination controller for executing the braking force distribution method based on a distributed braking drive control architecture as described in any of the technical solutions of the first aspect, including: Braking demand acquisition module, acquires the total braking torque demand of the vehicle; The initial allocation module allocates the total braking torque requirement of the vehicle to each wheel according to the ideal braking force allocation strategy, obtains the initial target wheel end total torque of each wheel, and sends it to the wheel end node of each wheel. The residual acquisition module acquires the actual achievable torque and the missing residual reported by each wheel end node for the corresponding wheel; the actual achievable torque and the missing residual are obtained by regenerative priority allocation of the initial target wheel end total torque based on the upper limit of regenerative braking torque and the upper limit of EMB friction braking torque. The secondary allocation module performs secondary torque allocation based on the actual achievable torque and residual deficit of each wheel, generating the final target total torque at the wheel end of each wheel and sending it to the wheel end node of each wheel.

[0020] Fourthly, the technical solution of this application provides a wheel-end node for executing the braking force distribution method based on a distributed braking drive control architecture as described in any of the technical solutions of the second aspect, including: The receiving module receives the initial target total wheel-end torque sent by the coordination controller; The allocation and residual determination module performs regeneration priority allocation on the initial target wheel end total torque based on the upper limit of regenerative braking torque and the upper limit of EMB friction braking torque of the corresponding wheel at the current moment, determines the actual achievable torque and the missing residual, and reports the actual achievable torque and the missing residual to the coordination controller. The final target receiving module receives the final wheel-end target total torque generated by the coordination controller after secondary allocation based on the actual achievable torque and the deficit residual; The instruction generation module generates the final regenerative braking torque and the final EMB friction braking torque based on the final target total torque at the wheel end, and sends them to the motor controller and the EMB actuator, respectively.

[0021] Fifthly, the present application provides a computer-readable storage medium storing program information, wherein a computer reads the program information and executes the steps of the braking force distribution method based on the distributed braking drive control architecture as described in either the first or second aspect.

[0022] Sixthly, the present application provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps of the braking force distribution method based on the distributed braking drive control architecture as described in either the first or second aspect.

[0023] In a seventh aspect, the present application provides an electronic device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the braking force distribution method based on the distributed braking drive control architecture as described in the first or second aspect.

[0024] Eighthly, the technical solution of this application provides a braking force distribution system based on a distributed braking drive control architecture, including the coordination controller described in the third aspect and multiple wheel-end nodes described in the fourth aspect, with each search wheel-end node corresponding to a wheel.

[0025] The technical solution provided in this application has the following technical effects compared with the prior art: The braking force distribution method and system based on the distributed braking drive control architecture provided in this application realizes the secondary distribution of braking force under the distributed braking drive architecture through the closed-loop interaction between the coordination controller and each wheel-end node: The coordination controller first generates the initial target wheel-end total torque of each wheel according to the total braking torque requirement of the whole vehicle and the ideal braking force distribution strategy, and sends it to the wheel-end node. The wheel-end node performs regenerative priority allocation of the initial target wheel-end total torque according to the upper limit of regenerative braking torque and the upper limit of EMB braking torque of its wheel at the current moment, determines the actual achievable torque and the deficit residual, and reports it to the coordination controller. The coordination controller then performs secondary torque allocation according to the actual achievable torque and deficit residual reported by each wheel, generates the final wheel-end target total torque and sends it to each wheel-end node. The wheel-end node finally generates regenerative braking torque command and EMB friction braking torque command and sends them to the motor controller and EMB actuator respectively. Therefore, this application can consider the dynamic differences between the regenerative braking capacity and EMB capacity of each wheel end in real time, avoiding the loss of braking force due to insufficient capacity of a single wheel, and improving the consistency of the vehicle's braking response and the adaptability of braking force distribution. At the same time, through the closed-loop mechanism of wheel end nodes reporting the actual achievable torque and the deficit residual, and the coordination controller re-executing the secondary distribution, the deficit braking force can be transferred to the wheel with surplus capacity, maintaining yaw stability while meeting the total braking force requirements of the vehicle. In addition, since the wheel end nodes can perform regenerative priority distribution again according to the actual capacity of the wheel during the final execution, it is beneficial to improve the efficiency of regenerative braking energy recovery while ensuring braking stability. Attached Figure Description

[0026] Figure 1 A flowchart illustrating a braking force distribution method based on a distributed braking drive control architecture applied to a coordination controller, as provided in one embodiment of this application; Figure 2 This is a flowchart illustrating the process of obtaining the total braking torque requirement of a vehicle in one embodiment of this application. Figure 3 This is a flowchart illustrating the process of obtaining the initial target total wheel end torque for each wheel in one embodiment of this application. Figure 4 This is a flowchart illustrating the fast analytical redistribution method for performing secondary torque redistribution in one embodiment of this application; Figure 5 This is a flowchart illustrating the optimized secondary torque distribution method used in one embodiment of this application. Figure 6 A flowchart illustrating a braking force distribution method based on a distributed braking drive control architecture applied to wheel-end nodes, as provided in one embodiment of this application; Figure 7 This is a flowchart illustrating the specific process for determining the actual achievable torque and the shortfall residual in one embodiment of this application; Figure 8 This is a schematic diagram of the structure of a coordination controller provided in one embodiment of this application; Figure 9 This is a schematic diagram of the structure of a wheel end node provided in one embodiment of this application; Figure 10 A schematic diagram of a braking force distribution system based on a distributed braking drive control architecture provided in one embodiment of this application; Figure 11 This is a schematic diagram of the structure of an electronic device provided in one embodiment of this application. Detailed Implementation

[0027] The specific embodiments of this application will be further described below with reference to the accompanying drawings.

[0028] It is readily understood that, based on the technical solution of this application, various structural and implementation methods can be interchanged by those skilled in the art without altering the essential spirit of this application. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solution of this application and should not be considered as the entirety of this application or as limitations or restrictions on the technical solution of the application.

[0029] This embodiment provides a braking force distribution method based on a distributed braking drive control architecture, applied to a coordination controller, such as... Figure 1 As shown, the method includes: S100: Obtain the total braking torque requirement of the entire vehicle.

[0030] Specifically, the total braking torque demand of the vehicle represents the total braking torque that the vehicle needs to apply during the current braking process, which can be determined by the coordination controller based on the vehicle's operating status. After obtaining the total braking torque demand of the vehicle, the coordination controller uses it as the input for subsequent braking force distribution.

[0031] S200: Based on the ideal braking force distribution strategy, the total braking torque requirement of the entire vehicle is distributed to each wheel to obtain the initial target wheel-end total torque of each wheel and sent to the wheel-end node of each wheel.

[0032] Specifically, the ideal braking force distribution strategy refers to the principle of front-to-rear axle braking force distribution that enables the front and rear wheels of a vehicle to fully utilize road adhesion conditions while ensuring braking directional stability. The coordination controller distributes the total braking torque demand of the entire vehicle to each wheel according to this strategy, obtaining the initial target wheel-end total torque for each wheel, and then sends the initial target wheel-end total torque to the corresponding wheel-end nodes. This stage does not heavily rely on the real-time capabilities of the wheel-end nodes; it only provides the desired wheel-end total torque.

[0033] S300: Obtain the actual achievable torque and the shortfall residual reported by each wheel end node for the corresponding wheel; the actual achievable torque and the shortfall residual are obtained by regenerating the initial target wheel end total torque according to the upper limit of regenerative braking torque and the upper limit of EMB friction braking torque.

[0034] Specifically, after receiving the initial target total wheel-end torque, each wheel-end node, based on the current regenerative braking torque limit and the EMB friction braking torque limit of its wheel, prioritizes the regenerative braking, supplementing any shortfall with EMB friction braking. This determines the actual achievable torque and residual deficit for its wheel. Each wheel-end node reports the actual achievable torque and residual deficit to the coordination controller. The coordination controller then obtains the actual achievable torque and residual deficit for the corresponding wheel reported by each wheel-end node.

[0035] S400: Based on the actual achievable torque and residual deficit of each wheel, perform secondary torque distribution to generate the final target total torque at the wheel end of each wheel and send it to the wheel end node of each wheel.

[0036] Specifically, after acquiring the actual achievable torque and deficit residuals of each wheel, the coordination controller performs secondary torque allocation based on these parameters. The purpose of this secondary allocation is to absorb the deficit residuals reported by each wheel, ensuring that the total braking force of the vehicle meets the total braking torque requirement as much as possible. After performing the secondary allocation, the coordination controller generates the final target total torque at each wheel's wheel end and sends this final target total torque to the corresponding wheel-end nodes, allowing each wheel-end node to generate the final regenerative braking torque command and the EMB friction braking torque command.

[0037] The braking force distribution method based on the distributed braking drive control architecture provided in this embodiment involves the coordinating controller obtaining the total braking torque demand of the vehicle and then distributing it to each wheel according to the ideal braking force distribution strategy. This yields the initial target wheel-end total torque for each wheel and sends it to the wheel-end nodes of each wheel. Each wheel-end node performs regenerative priority allocation of the initial target wheel-end total torque based on the upper limit of regenerative braking torque and the upper limit of EMB friction braking torque at the current moment, determines the actual achievable torque and the deficit residual, and reports it to the coordinating controller. The coordinating controller then performs a secondary torque allocation based on the actual achievable torque and the deficit residual of each wheel, generating the final wheel-end target total torque for each wheel and sending it to the wheel-end nodes of each wheel. Therefore, this embodiment, through the closed-loop interaction between the coordination controller and each wheel-end node, enables the coordination controller to directly obtain the actual achievable torque and residual deficit obtained by each wheel-end node after prioritizing regeneration based on its own actual capabilities. This allows for real-time consideration of the dynamic differences between the regenerative braking capabilities and EMB friction braking capabilities of each wheel end. Simultaneously, by performing secondary torque allocation based on the actual achievable torque and residual deficit of each wheel, the residual deficit caused by insufficient capability of a single wheel can be recoordinated and allocated at the vehicle level, avoiding the loss of braking force due to insufficient capability of a single wheel and improving the consistency of the vehicle's braking response and the adaptability of braking force distribution.

[0038] Furthermore, such as Figure 2 As shown, obtaining the total braking torque requirement of the vehicle as described in S100 includes: S101: Obtain the vehicle's actual speed and target speed.

[0039] Specifically, the coordination controller obtains the vehicle's actual speed through the vehicle speed sensor and the target speed through the vehicle control network. The target speed can be provided by the vehicle control module based on driver intent, cruise control requests, or speed planning by the autonomous driving system. The coordination controller compares the actual speed with the target speed to obtain the deviation between the two speeds.

[0040] S102: Based on the deviation between the actual vehicle speed and the target vehicle speed, the total braking torque requirement of the vehicle is calculated using a proportional-integral controller combined with a feedforward braking torque term.

[0041] Specifically, in the proportional-integral controller, the proportional term responds quickly to the current speed deviation; the larger the deviation, the greater the calculated braking torque. The integral term responds to the accumulation of speed deviation over time and is used to eliminate steady-state deviation. The feedforward braking torque term is used to respond to braking demand in advance before the speed deviation is fully established, thereby accelerating the braking response speed.

[0042] The coordination controller uses a proportional-integral controller, which adds the proportional term, integral term and feedforward braking torque term to obtain the total braking torque requirement of the vehicle.

[0043] Furthermore, the total braking torque requirement of the vehicle is calculated in S102 as follows: ; in, For the total braking torque requirement of the entire vehicle, It is a saturation function. This is the proportionality coefficient. This refers to the deviation between the actual vehicle speed and the target vehicle speed. The integral coefficient is... This is the feedforward braking torque term. This is the maximum braking torque of the entire vehicle.

[0044] In the above formula, the proportional term Integral terms and feedforward braking torque term The values ​​are summed to obtain the initial calculated value of the total braking torque requirement of the vehicle. Subsequently, the coordinated controller uses a saturation function... Limit the initial calculated values ​​to [ Within the range. The lower limit of the saturation function is 0 (when the actual vehicle speed is lower than the target vehicle speed, the speed deviation is zero). If the value is negative, the proportional term This value is also negative, meaning the initial calculated value might be negative. Without restrictions, the total braking torque demand of the vehicle would be negative, which physically implies a drive torque request. By setting the lower limit of the saturation function to 0, the coordinating controller outputs a zero braking torque request when the initial calculated value is negative, thus ensuring that the coordinating controller only outputs a braking torque request and not a drive torque request. This ensures that the total braking torque demand of the vehicle is not negative, thereby preventing the coordinating controller from outputting a drive torque request. The upper limit of the saturation function is the maximum braking torque of the vehicle. This is used to ensure that the total braking torque demand of the vehicle does not exceed the upper limit of the vehicle's braking force, avoiding the request of unattainable braking force. Through this method, the coordination controller can calculate the total braking torque demand of the vehicle in real time based on the deviation between the actual vehicle speed and the target vehicle speed, providing vehicle-level input for the subsequent distribution of the total braking torque demand to each wheel.

[0045] In practice, the feedforward braking torque term is determined based on at least one of the desired deceleration, gradient, or vehicle resistance. Specifically, the feedforward braking torque term... It is a pre-calculated braking torque compensation amount used to respond to braking demands before the speed deviation has fully established. For example: When the vehicle control module (including adaptive cruise control or autonomous driving system) gives the desired deceleration At that time, the coordinated controller can pre-calculate the feedforward braking torque term based on the desired deceleration: ; in, m For the overall vehicle quality, r This is the rolling radius of the wheel.

[0046] Once the desired deceleration is determined, the coordinated controller can directly calculate the required braking torque based on the vehicle's mass and wheel rolling radius, and use this as the feedforward braking torque term. In this way, the coordinated controller can output a braking request in advance, before the speed deviation has fully materialized, thus improving braking response speed.

[0047] For example, when a vehicle is traveling on a slope, the component of gravity along the slope will cause the vehicle to experience acceleration related to the slope. The coordinated controller can pre-calculate the slope drag torque based on the slope estimate and use it as a feedforward braking torque term: ; in, m For the overall vehicle quality, It is the acceleration due to gravity. θ The slope angle, r This is the wheel's rolling radius.

[0048] For example, when a vehicle is driving downhill, if the gradient is estimated to be 5 degrees, the coordination controller can calculate the gradient resistance torque according to the above formula and use it as the feedforward braking torque term, thereby applying the brakes in advance before the speed deviation increases significantly, thus suppressing the increase in vehicle speed.

[0049] For example, vehicles also experience air resistance and rolling resistance during operation. The coordinated controller can pre-calculate the resistance torque based on the vehicle resistance model and use it as a feedforward braking torque term. ; in, For air resistance, For rolling resistance, r This is the wheel's rolling radius. Air resistance can be calculated based on vehicle speed, air density, frontal area, and air resistance coefficient, while rolling resistance can be calculated based on vehicle mass, gravitational acceleration, and rolling resistance coefficient.

[0050] The three methods described above can be used individually or in combination. When used in combination, they can more comprehensively cover braking requirements under different operating conditions, further improving braking response speed and control accuracy.

[0051] More preferably, such as Figure 3As shown, in S200, the initial target total wheel end torque of each wheel is obtained in the following way: S201: Obtain the current axle load transfer amount and determine the longitudinal distribution coefficient of each wheel based on the current axle load transfer amount.

[0052] Specifically, when a vehicle brakes, due to inertial forces, the front axle load increases and the rear axle load decreases, i.e., axle load transfer occurs. The coordination controller obtains the current axle load transfer amount and determines the longitudinal distribution coefficient of each wheel based on the current axle load transfer amount.

[0053] Axle load transfer can be calculated based on the current longitudinal acceleration, vehicle center of gravity height, wheelbase, and distance from the center of gravity to the front axle. For example, the increase in front axle load during braking can be expressed as: ; in, m For the overall vehicle quality, For longitudinal acceleration, For the height of the center of mass, L This refers to the wheelbase. Increased front axle load. The rear axle load is reduced accordingly. .

[0054] The coordination controller determines the longitudinal distribution coefficient of each wheel based on the axle load transfer. The ideal braking force distribution strategy requires the front and rear axle braking force distribution to be as close as possible to the ideal braking force distribution relationship, in order to fully utilize road adhesion conditions and ensure braking directional stability. When the axle load transfers forward, the front axle load increases, and the front axle wheels can bear a larger proportion of the braking force distribution; the rear axle load decreases, and the rear axle wheels should bear a smaller proportion of the braking force distribution. The coordination controller determines the longitudinal distribution coefficient of each wheel accordingly, so that the wheels with increased load bear a larger proportion of the braking force distribution, and the wheels with decreased load bear a smaller proportion of the braking force distribution.

[0055] S202: The total braking torque requirement of the whole vehicle is distributed to each wheel according to the longitudinal distribution coefficient of each wheel to obtain the initial target wheel end total torque of each wheel.

[0056] In this step, , Let be the longitudinal distribution coefficient for the i-th wheel. The coordination controller sends the initial target total wheel-end torque of each wheel to the corresponding wheel-end node, so that each wheel-end node can prioritize regeneration distribution based on the upper limit of regenerative braking torque and the upper limit of EMB friction braking torque of its current wheel. In this way, the coordination controller can determine the longitudinal distribution coefficient of each wheel based on the current axle load transfer amount, and distribute the total braking torque requirement of the whole vehicle to each wheel according to the longitudinal distribution coefficient. This makes the initial target total wheel-end torque of each wheel match the actual axle load distribution during braking, which is beneficial to make full use of road adhesion conditions and ensure braking directional stability.

[0057] Preferably, the step of obtaining the initial target total wheel end torque of each wheel in S200 further includes: S203: The initial target wheel-end total torque is corrected according to the yaw torque correction term. The corrected initial target wheel-end total torque is expressed as: ; in, Let be the initial target total wheel end torque of the i-th wheel. Let be the longitudinal distribution coefficient for the i-th wheel. For the total braking torque requirement of the entire vehicle, This is the yaw torque correction term for the i-th wheel, which is zero when there is no stability control request.

[0058] In this scheme, the yaw torque correction term This is an interface reserved for stability control. When a vehicle stability control system (such as ESC: Electronic Stability Control) issues a stability control request, the coordinating controller determines the yaw torque correction term for each wheel based on the request and adds it to the initial target wheel-end total torque of the corresponding wheel. This generates an additional yaw moment by adjusting the braking force difference between the left and right wheels, correcting the vehicle's yaw attitude. When there is no stability control request, the yaw torque correction term is zero, and the initial target wheel-end total torque is the value obtained by allocating according to the longitudinal distribution coefficient. In this way, the coordinating controller can take into account the vehicle's yaw stability requirements in the initial allocation stage, providing a corrected initial target wheel-end total torque for subsequent wheel-end regeneration priority allocation and secondary allocation.

[0059] More preferably, such as Figure 4 As shown, in S400, secondary torque distribution is performed, including: S401: Calculate the total deficit of all wheels and the surplus capacity of each wheel.

[0060] Specifically, the coordination controller calculates the total deficit of all wheels and the redundancy capacity of each wheel based on the actual achievable torque and deficit residual reported by each wheel-end node. The total deficit represents the sum of braking torques that cannot be achieved by each wheel due to insufficient capacity. The coordination controller accumulates the positive values ​​of the deficit residuals of each wheel to obtain the total deficit. Redundancy capacity represents the additional braking torque that a wheel can still bear after meeting the initial target total wheel-end torque.

[0061] S402: The total deficit is redistributed according to the proportion of surplus capacity of each wheel, and yaw torque constraints are applied to the compensation torque difference between the left and right wheels on the same axle to obtain the final target total torque at the wheel end of each wheel.

[0062] This step allows the wheel with greater spare capacity to bear more compensating braking torque, thus achieving true coordinated distribution.

[0063] In practical implementation, the final target total torque at the wheel ends of each wheel is expressed as: ; ; ; ; ; ; in, Let be the final target total torque at the wheel end of the i-th wheel. Let be the initial target total wheel end torque of the i-th wheel. Let be the compensation torque for the i-th wheel. Let be the residual deficit of the i-th wheel. This represents the final target total torque at the wheel end of the left front wheel. This represents the final target total torque at the wheel end of the right front wheel. This represents the final target total torque at the left rear wheel end. This represents the final target total torque at the wheel end of the right rear wheel. The yaw torque threshold is the difference between the final target total torque at the wheel ends of the left and right wheels on the same axle. This represents the total shortfall. Let be the spare capacity of the i-th wheel. Let j be the spare capacity of the j-th wheel. This represents the upper limit of the regenerative braking torque for the i-th wheel. This represents the upper limit of the EMB friction braking torque for the i-th wheel.

[0064] Based on the above formula combination, the coordination controller first calculates the total deficit according to the deficit residuals of each wheel. R This means that only the positive values ​​in the deficit residuals of each wheel are accumulated; then, the surplus capacity of each wheel is calculated based on the upper limit of regenerative braking torque, the upper limit of EMB friction braking torque, and the initial target wheel-end total torque. Then calculate the total shortfall. R The excess capacity of each wheel is redistributed to the wheels with compensation capacity according to the proportion of each wheel's capacity, thus obtaining the compensation torque for each wheel. .

[0065] When determining the final target total torque at the wheel ends of each wheel, the coordination controller applies a yaw torque constraint to the difference between the final target total torque at the wheel ends of the left and right wheels on the same axle: the difference between the final target total torque at the wheel ends of the left front wheel and the right front wheel on the front axle does not exceed the yaw torque threshold. The difference between the final target total torque at the wheel ends of the left and right rear wheels of the rear axle does not exceed the yaw torque threshold. This constraint prevents excessive yaw torque caused by the difference in braking force between the left and right wheels on the same axle due to secondary distribution, thus ensuring yaw stability during vehicle braking.

[0066] For wheels with insufficient residual torque, the corresponding insufficient residual torque is subtracted from their initial target total wheel-end torque; for wheels with surplus capacity, the corresponding compensation torque is added to their initial target total wheel-end torque. The coordination controller thus obtains the final target total wheel-end torque for each wheel. The command is then sent to the wheel-end nodes corresponding to each wheel, so that each wheel-end node can generate the final regenerative braking torque command and EMB friction braking torque command.

[0067] As another feasible solution, such as Figure 5 As shown, the secondary torque distribution is performed, including: S41: Construct the objective function and set its constraints: ; in, Let represent the final target total torque at the wheel end of the i-th wheel, used as an optimization variable. Let i be the regenerative braking torque of the i-th wheel. Let be the EMB friction braking torque of the i-th wheel, and , For the first i The upper limit of regenerative braking torque per wheel; For friction braking weight, For regenerative braking weight, This is a stability penalty function; The constraints of the objective function include: Longitudinal braking force tracking constraint: The deviation between the total braking torque requirement of the vehicle and the set threshold shall not exceed. Wheel end capability limit constraints: ; For the first i The upper limit of EMB friction braking torque for each wheel; Yaw torque constraint: The difference between the final target total torque at the wheel ends of the left and right wheels on the same axle shall not exceed the yaw torque threshold. S42: Solve the objective function to obtain the final target total torque at the wheel end of each wheel.

[0068] Specifically, the coordination controller uses the final target total torque at the wheel ends of each wheel. To optimize the variables, the above objective function is constructed. This objective function consists of three parts: the first part is the friction braking term. Through friction braking weight The degree of EMB friction braking participation is suppressed; the second part is the regenerative braking item. Through regenerative braking weight Encouraging regenerative braking participation to improve energy recovery efficiency; the third part is the stability penalty function. It is used to penalize torque distribution results that may cause vehicle yaw instability, such as penalizing situations where the torque difference between the left and right wheels on the same axle is too large.

[0069] Regarding the constraints, the longitudinal braking force tracking constraint requires that the deviation between the sum of the final target total torque at the wheel end of each wheel and the total braking torque requirement of the vehicle does not exceed a set threshold, so as to ensure that the total braking force of the vehicle meets the braking requirements; the wheel end capacity limit constraint requires that the final target total torque at the wheel end of each wheel does not exceed the sum of the upper limit of the regenerative braking torque of that wheel and the upper limit of the EMB friction braking torque, so as to ensure that the distribution result is within the wheel end execution capability range; the yaw torque constraint requires that the difference between the final target total torque at the wheel end of the two wheels on the same axle does not exceed the yaw torque threshold, so as to ensure that the secondary distribution does not destroy the yaw stability of the vehicle.

[0070] The coordination controller solves the objective function under the above constraints to obtain the final total target torque at each wheel end that minimizes the objective function, and sends it to the corresponding wheel end node so that each wheel end node can generate the final regenerative braking torque command and EMB friction braking torque command.

[0071] Through the above-mentioned optimized secondary distribution method, the coordinating controller can achieve optimized distribution of braking force under the distributed braking drive architecture, while meeting the requirements of longitudinal braking force tracking, wheel-end capacity limits and yaw torque constraints, and taking into account friction braking suppression, regenerative braking energy recovery and vehicle yaw stability.

[0072] This application also provides a braking force distribution method based on a distributed braking drive control architecture, applied to wheel-end nodes, such as... Figure 6 As shown, it includes: S610: Receives the initial target total wheel end torque issued by the coordination controller.

[0073] Specifically, each wheel-end node corresponds to one wheel and is connected to the coordination controller via a communication network. After generating the initial target total wheel-end torque for each wheel based on the vehicle's total braking torque requirement and the ideal braking force distribution strategy, the coordination controller sends the initial target total wheel-end torque for each wheel to the corresponding wheel-end node. The wheel-end node receives the initial target total wheel-end torque for its own wheel from the coordination controller.

[0074] S620: Based on the upper limit of regenerative braking torque and the upper limit of EMB friction braking torque of the corresponding wheel at the current moment, regenerative priority allocation is performed on the total torque at the initial target wheel end to determine the actual achievable torque and the shortfall residual, and the actual achievable torque and the shortfall residual are reported to the coordination controller.

[0075] Specifically, after receiving the initial target total wheel-end torque, the wheel-end node performs regenerative priority allocation of the initial target total wheel-end torque based on the upper limit of regenerative braking torque and the upper limit of EMB friction braking torque at the current moment. Regenerative priority allocation means that regenerative braking is used first to meet the initial target total wheel-end torque, and the part that is insufficient by regenerative braking is supplemented by EMB friction braking.

[0076] The wheel-end node determines the actual achievable torque and the shortfall residual based on whether the sum of the upper limit of regenerative braking torque and the upper limit of EMB friction braking torque can meet the initial target total wheel-end torque. After determining the actual achievable torque and the shortfall residual, the wheel-end node reports the actual achievable torque and the shortfall residual to the coordination controller, so that the coordination controller can perform secondary torque distribution.

[0077] S630: Receives the final target total wheel-end torque generated by the coordination controller after secondary allocation based on the actual achievable torque and the deficit residual.

[0078] Specifically, after receiving the actual achievable torque and deficit residuals reported by each wheel-end node, the coordination controller performs secondary torque allocation to absorb the deficit residuals of each wheel and satisfy stability constraints, generating the final target total torque for each wheel, and then sending the final target total torque for each wheel to the corresponding wheel-end node. The wheel-end node receives the final target total torque for its own wheel from the coordination controller.

[0079] S640: Based on the final target total torque at the wheel end, generate the final regenerative braking torque and the final EMB friction braking torque, and send them to the motor controller and the EMB actuator respectively.

[0080] Specifically, after receiving the final target total torque at the wheel end, the wheel-end node performs regenerative priority allocation again based on the upper limit of the regenerative braking torque of this wheel, generating the final regenerative braking torque and the final EMB friction braking torque. That is, the wheel-end node determines the smaller value between the final target total torque at the wheel end and the upper limit of the regenerative braking torque as the final regenerative braking torque, and determines the difference between the final target total torque at the wheel end and the final regenerative braking torque as the final EMB friction braking torque.

[0081] The wheel-end node sends the final regenerative braking torque command to the motor controller, which then controls the hub motor to output the corresponding regenerative braking torque; it also sends the final EMB friction braking torque command to the EMB actuator, which then controls the EMB to output the corresponding friction braking torque.

[0082] In this way, the wheel-end node can prioritize the regenerative braking torque allocation based on the upper limit of the regenerative braking torque and the upper limit of the EMB friction braking torque of the wheel at the current moment, and report the actual achievable torque and the shortfall residual to the coordination controller; then, based on the final wheel-end target total torque generated after the secondary allocation by the coordination controller, the final regenerative braking torque and the final EMB friction braking torque are generated and sent to the motor controller and the EMB actuator respectively, thereby realizing the allocation and execution of braking force on the wheel-end node side.

[0083] This embodiment performs regenerative priority allocation locally at the wheel-end nodes, enabling the braking force distribution to take into account the actual state of the wheel's regenerative braking capacity and EMB friction braking capacity in real time. This avoids allocation deviations caused by the coordination controller's inability to obtain real-time wheel-end capabilities. Simultaneously, the wheel-end nodes report the actual achievable torque and the shortfall residual to the coordination controller, providing the coordination controller with true and accurate wheel-end execution status information for secondary torque allocation. This allows the shortfall residual caused by insufficient capacity in a single wheel to be recoordinated and allocated at the vehicle level, avoiding braking force loss due to insufficient capacity in a single wheel. Furthermore, after receiving the final target total torque at the wheel-end nodes, the wheel-end nodes perform regenerative priority allocation again, prioritizing the use of regenerative braking while meeting the final target total torque. This improves energy recovery efficiency and ensures that the final regenerative braking torque and the final EMB friction braking torque are accurately sent to the motor controller and EMB actuator, respectively, achieving accurate execution of braking force at the wheel-end side.

[0084] Furthermore, such as Figure 7 As shown, the steps in S620 for determining the actual achievable torque and the shortfall residual include: S621: Determine the regenerative braking torque and EMB required torque based on the upper limit of regenerative braking torque and the initial target wheel-end total torque.

[0085] Specifically, after receiving the initial target total wheel end torque from the coordination controller, the wheel end node performs regeneration priority allocation based on the upper limit of the regenerative braking torque of the wheel at the current moment and the initial target total wheel end torque.

[0086] In practice, the final regenerative braking torque and the final EMB friction braking torque are generated in the following manner: ; ; in, Let be the final regenerative braking torque of the i-th wheel. Let be the final target total torque at the wheel end of the i-th wheel. This represents the upper limit of the regenerative braking torque for the i-th wheel. Let be the final EMB friction braking torque of the i-th wheel.

[0087] That is, the wheel-end node determines the smaller value between the initial target wheel-end total torque and the upper limit of the regenerative braking torque as the regenerative braking torque.

[0088] S622: When the EMB required torque exceeds the upper limit of the EMB friction braking torque, the sum of the upper limit of the regenerative braking torque and the upper limit of the EMB friction braking torque is determined as the actual achievable torque, and the difference between the initial target wheel end total torque and the actual achievable torque is determined as the deficit residual.

[0089] Specifically, when the EMB required torque exceeds the upper limit of the EMB friction braking torque, it indicates that the sum of regenerative braking and EMB friction braking is still insufficient to meet the initial target total wheel end torque. At this time, the wheel end node determines the sum of the upper limit of regenerative braking torque and the upper limit of EMB friction braking torque as the actual achievable torque, and determines the difference between the initial target total wheel end torque and the actual achievable torque as the deficit residual.

[0090] S623: When the required torque of the EMB does not exceed the upper limit of the friction braking torque of the EMB, the initial target wheel end total torque is determined as the actual achievable torque, and the deficit residual is zero.

[0091] Specifically, when the required torque of EMB does not exceed the upper limit of EMB friction braking torque, it means that regenerative braking and EMB friction braking can meet the initial target wheel end total torque. At this time, the wheel end node determines the initial target wheel end total torque as the actual achievable torque and determines the deficit residual as zero.

[0092] In this way, the wheel-end node can prioritize the regeneration of the initial target wheel-end total torque based on the upper limit of the regenerative braking torque of the wheel at the current moment and the upper limit of the EMB friction braking torque, and accurately determine the actual achievable torque and the shortfall residual, providing the coordinating controller with real and accurate wheel-end execution status information for performing secondary torque allocation.

[0093] Furthermore, in S640, when generating the final regenerative braking torque and the final EMB friction braking torque, the following fault degradation logic is superimposed: (1) If the regenerative braking system of the corresponding wheel fails, the upper limit of the regenerative braking torque is set to zero, and the full friction braking strategy is output.

[0094] Specifically, when the wheel-end node detects a fault in the regenerative braking system of its wheel, such as a hub motor failure, motor controller failure, battery inability to charge, or related communication interruption, the wheel-end node sets the upper limit of the regenerative braking torque of its wheel to zero. This ensures that the regenerative braking torque is zero during regenerative priority allocation, and all braking torque is borne by EMB friction braking, i.e., outputting a full friction braking strategy. Therefore, even when the regenerative braking system fails, the braking capability of the wheel can still be guaranteed through EMB friction braking.

[0095] (2) If the corresponding wheel has an EMB fault, output a safety mode request and limit the target deceleration.

[0096] Specifically, when the wheel-end node detects a fault in the EMB of its own wheel, since the EMB cannot output friction braking torque normally, the wheel-end node outputs a safety mode request and limits the target deceleration to prompt the coordination controller and the driver to reduce braking intensity and avoid insufficient braking force due to EMB failure, which could affect braking safety. In safety mode, the coordination controller can adjust the braking force distribution of other wheels accordingly to maintain the overall vehicle braking capacity as much as possible.

[0097] Through the above-described fault degradation logic, the wheel-end node can promptly take corresponding degradation measures in the event of a regenerative braking system failure or an EMB failure, ensuring the safety and controllability of the braking system under abnormal operating conditions. This application also provides a coordination controller, such as... Figure 8 As shown, the braking force distribution method based on the distributed braking drive control architecture described in S100-S400 of the foregoing embodiments includes: Braking demand acquisition module 810 acquires the total braking torque demand of the vehicle. The initial allocation module 820 allocates the total braking torque requirement of the vehicle to each wheel according to the ideal braking force allocation strategy, obtains the initial target wheel end total torque of each wheel, and sends it to the wheel end node of each wheel. The residual acquisition module 830 acquires the actual achievable torque and the missing residual reported by each wheel end node for the corresponding wheel; the actual achievable torque and the missing residual are obtained by regenerative priority allocation of the initial target wheel end total torque based on the upper limit of regenerative braking torque and the upper limit of EMB friction braking torque. The secondary allocation module 840 performs secondary torque allocation based on the actual achievable torque and the shortfall residual of each wheel, generates the final target total torque at the wheel end of each wheel, and sends it to the wheel end node of each wheel.

[0098] Through the coordinated operation of the above modules, the coordination controller provided in this embodiment can realize the braking force distribution method based on the distributed braking drive control architecture described in S100-S400 of the aforementioned embodiments. Through the closed-loop interaction between the coordination controller and each wheel-end node, the dynamic differences between the regenerative braking capability and EMB friction braking capability of each wheel end are considered in real time. This allows the residual deficit caused by insufficient capability of a single wheel to be recoordinated and distributed at the vehicle level, avoiding the loss of braking force due to insufficient capability of a single wheel, and improving the consistency of vehicle braking response and the adaptability of braking force distribution.

[0099] More preferably, the braking demand acquisition module 810 includes: The vehicle speed acquisition unit is used to acquire the vehicle's actual speed and target speed. The demand calculation unit is used to calculate the total braking torque demand of the vehicle based on the deviation between the actual vehicle speed and the target vehicle speed, using a proportional-integral controller combined with a feedforward braking torque term.

[0100] Specifically, after acquiring the vehicle's actual speed and target speed, the vehicle speed acquisition unit transmits them to the demand calculation unit. The demand calculation unit calculates the total braking torque demand of the vehicle based on the deviation between the actual and target speeds, using a proportional-integral controller combined with a feedforward braking torque term. The proportional term is used for rapid response to current speed deviations, the integral term is used to eliminate steady-state deviations, and the feedforward braking torque term is used to respond to braking demands in advance before the speed deviation is fully established. The feedforward braking torque term is determined based on at least one of the desired deceleration, gradient, or vehicle resistance.

[0101] More preferably, the initial allocation module 820 includes: The axle load transfer acquisition unit is used to acquire the current axle load transfer amount and determine the longitudinal distribution coefficient of each wheel based on the current axle load transfer amount. The initial allocation unit is used to allocate the total braking torque requirement of the vehicle to each wheel according to the longitudinal allocation coefficient of each wheel, so as to obtain the initial target wheel end total torque of each wheel.

[0102] Specifically, after acquiring the current axle load transfer amount, the axle load transfer acquisition unit determines the longitudinal distribution coefficient of each wheel based on the current axle load transfer amount and transmits it to the initial distribution unit. The initial distribution unit distributes the total braking torque requirement of the entire vehicle to each wheel according to the longitudinal distribution coefficient of each wheel, thereby obtaining the initial target wheel-end total torque of each wheel.

[0103] More preferably, the initial allocation module 820 further includes: The yaw correction unit is used to correct the initial target wheel end total torque according to the yaw torque correction term, so as to obtain the corrected initial target wheel end total torque.

[0104] Specifically, after the initial allocation unit obtains the initial target wheel-end total torque, the yaw correction unit corrects the initial target wheel-end total torque according to the yaw torque correction term. The yaw torque correction term is a reserved interface for stability control and is zero when there is no stability control request.

[0105] More preferably, the secondary allocation module 840 includes: The total deficit calculation unit is used to determine the total deficit based on the deficit residuals of each wheel; The redundancy capacity calculation unit is used to determine the redundancy capacity of each wheel based on the actual achievable torque of each wheel and the initial target total wheel end torque. The compensation allocation unit is used to redistribute the total deficit to the wheels with compensation capabilities according to the proportion of the surplus capacity of each wheel, and generate the final target total torque at the wheel end of each wheel; the compensation allocation unit is also used to apply yaw torque constraint to the difference in compensation torque between the left and right wheels on the same axle, so that the difference in the final target total torque at the wheel end of the left and right wheels on the same axle does not exceed a preset yaw torque threshold.

[0106] Specifically, the total deficit calculation unit determines the total deficit based on the deficit residual of each wheel; the surplus capacity calculation unit determines the surplus capacity of each wheel based on the actual achievable torque of each wheel and the initial target wheel-end total torque; the compensation allocation unit redistributes the total deficit to the wheels with compensation capacity according to the proportion of the surplus capacity of each wheel, generates the final wheel-end target total torque of each wheel, and applies yaw torque constraint to the difference in compensation torque between the left and right wheels on the same axle to avoid the additional yaw torque caused by the excessive difference in braking force between the left and right wheels due to secondary allocation, thus ensuring the yaw stability of the vehicle during braking.

[0107] As one feasible solution, the secondary allocation module 840 further includes: The objective function construction unit is used to construct an objective function that aims to minimize the friction braking weight and maximize the regenerative braking energy recovery. The constraint setting unit is used to set the constraint conditions of the objective function, including longitudinal braking force tracking constraint, wheel end capacity limit constraint and yaw torque constraint. The solution unit is used to solve the objective function to obtain the final target total torque at the wheel end of each wheel.

[0108] Specifically, after the objective function construction unit constructs an objective function with the goal of minimizing the friction braking weight and maximizing the regenerative braking energy recovery, the constraint setting unit sets the constraint conditions of the objective function, and the solution unit solves the objective function under the premise of satisfying the constraint conditions to obtain the final target total torque at the wheel end of each wheel.

[0109] This application embodiment also provides a wheel-end node for executing the braking force distribution method based on a distributed braking drive control architecture described in S610-S640 of the foregoing embodiments, such as... Figure 9 As shown, it includes: Receiver module 910 receives the initial target total wheel end torque sent by the coordination controller; The allocation and residual determination module 920 performs regeneration priority allocation on the initial target wheel end total torque based on the upper limit of regenerative braking torque and the upper limit of EMB friction braking torque of the corresponding wheel at the current moment, determines the actual achievable torque and the missing residual, and reports the actual achievable torque and the missing residual to the coordination controller. The final target receiving module 930 receives the final wheel-end target total torque generated by the coordination controller after secondary allocation based on the actual achievable torque and the deficit residual; The instruction generation module 940 generates the final regenerative braking torque and the final EMB friction braking torque based on the final target total torque at the wheel end, and sends them to the motor controller and the EMB actuator, respectively.

[0110] Through the collaborative work of the above modules, the wheel-end node provided in this embodiment can realize the braking force distribution method based on the distributed braking drive control architecture described in S610-S640 of the aforementioned embodiments. By performing regenerative priority allocation locally at the wheel-end node, the braking force distribution can take into account the actual state of the regenerative braking capability and EMB friction braking capability of the wheel in real time. At the same time, the wheel-end node reports the actual achievable torque and the deficit residual to the coordination controller, providing the coordination controller with real and accurate wheel-end execution status information for performing secondary torque allocation. This allows the deficit residual caused by insufficient capability of a single wheel to be recoordinated and allocated at the vehicle level, avoiding the loss of braking force due to insufficient capability of a single wheel.

[0111] More preferably, the allocation and residual determination module 920 includes: The regeneration priority allocation unit is used to determine the regeneration braking torque and EMB demand torque based on the upper limit of the regeneration braking torque and the initial target wheel end total torque; The first residual determination unit is used to determine the sum of the regenerative braking torque limit and the EMB friction braking torque limit as the actual achievable torque when the EMB demand torque exceeds the upper limit of the EMB friction braking torque, and to determine the difference between the initial target wheel end total torque and the actual achievable torque as the deficit residual. The second residual determination unit is used to determine the initial target wheel end total torque as the actual achievable torque when the EMB required torque does not exceed the upper limit of the EMB friction braking torque, and the missing residual is zero.

[0112] Specifically, the regeneration priority allocation unit determines the regeneration braking torque and the EMB demand torque based on the upper limit of the regeneration braking torque and the initial target total wheel-end torque. When the EMB demand torque exceeds the upper limit of the EMB friction braking torque, the first residual determination unit determines the sum of the upper limit of the regeneration braking torque and the upper limit of the EMB friction braking torque as the actual achievable torque, and determines the difference between the initial target total wheel-end torque and the actual achievable torque as the deficit residual; when the EMB demand torque does not exceed the upper limit of the EMB friction braking torque, the second residual determination unit determines the initial target total wheel-end torque as the actual achievable torque, and the deficit residual is zero.

[0113] More preferably, the instruction generation module 940 includes: The final regenerative torque determination unit is used to determine the final regenerative braking torque based on the final target total torque at the wheel end and the upper limit of the regenerative braking torque. The final EMB torque determination unit is used to determine the final EMB friction braking torque based on the final target total torque at the wheel end and the final regenerative braking torque. The transmitting unit is used to send the final regenerative braking torque command to the motor controller and the final EMB friction braking torque command to the EMB actuator.

[0114] Specifically, the final regenerative torque determination unit determines the final regenerative braking torque based on the final target total torque at the wheel end and the upper limit of the regenerative braking torque; the final EMB torque determination unit determines the final EMB friction braking torque based on the final target total torque at the wheel end and the final regenerative braking torque; the sending unit sends the final regenerative braking torque command to the motor controller and the final EMB friction braking torque command to the EMB actuator.

[0115] More preferably, the instruction generation module 940 further includes: The fault degradation unit is used to superimpose fault degradation logic when generating the final regenerative braking torque and the final EMB friction braking torque: if the regenerative braking system of the corresponding wheel fails, the upper limit of the regenerative braking torque is set to zero and the full friction braking strategy is output; if the EMB of the corresponding wheel fails, a safety mode request is output and the target deceleration is limited.

[0116] Specifically, the fault degradation unit superimposes fault degradation logic when generating the final regenerative braking torque and the final EMB friction braking torque. When the regenerative braking system of the corresponding wheel fails, the fault degradation unit sets the upper limit of the regenerative braking torque to zero and outputs a full friction braking strategy; when the EMB of the corresponding wheel fails, the fault degradation unit outputs a safety mode request and limits the target deceleration to ensure the safety and controllability of the braking system under abnormal operating conditions.

[0117] This application also provides a computer-readable storage medium storing program information. After reading the program information, a computer executes the steps of the braking force distribution method based on a distributed braking drive control architecture as described in any of the foregoing method embodiments. Specifically, the computer-readable storage medium may be, but is not limited to, read-only memory (ROM), random access memory (RAM), magnetic disk, optical disk, flash memory device, or other non-volatile solid-state storage devices. The program information may be stored in the storage medium in the form of a software program, a computer-executable program, or a module. When the computer reads and runs the program information, it executes the braking force distribution method based on a distributed braking drive control architecture as described in any of the foregoing method embodiments.

[0118] This application also provides a computer program product, including a computer program / instructions, which, when executed by a processor, implement the steps of the braking force distribution method based on a distributed braking drive control architecture as described in any of the foregoing method embodiments. Specifically, the computer program product can be written in any combination of one or more programming languages ​​to execute the methods described in this application embodiment. 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 programming languages. The computer program code can be executed entirely on a user computing device, partially on a user computing device, as a standalone software package, partially on a user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0119] This application also provides a braking force distribution system based on a distributed braking drive control architecture, such as... Figure 10 As shown, the system includes the coordination controller 1010 described in the preceding embodiments and multiple wheel-end nodes 1020 described in the preceding embodiments, each wheel-end node corresponding to a wheel. In this embodiment, the wheel-end node is a local controller located at the corresponding wheel and used to distribute and execute control of regenerative braking and EMB friction braking for that wheel. Specifically, the wheel-end node can be an independent wheel-end controller, or it can be integrated into an EMB wheel-end controller, or it can be integrated into a hub motor controller, or it can be implemented jointly by an EMB wheel-end controller and a hub motor controller.

[0120] Specifically, the coordination controller 1010 is connected to multiple wheel-end nodes 1020 via a communication network. Each wheel-end node 1020 corresponds to one wheel and is used to distribute and execute control of regenerative braking and EMB friction braking for that wheel. The coordination controller 1010 is used to obtain the total braking torque requirement of the entire vehicle, and distribute the total braking torque requirement of the entire vehicle to each wheel according to the ideal braking force distribution strategy, so as to obtain the initial target wheel-end total torque of each wheel and send it to the wheel-end node 1020 of each wheel. Each wheel-end node 1020 performs regenerative priority allocation on the initial target wheel-end total torque according to the upper limit of regenerative braking torque and the upper limit of EMB friction braking torque of its current wheel, determines the actual achievable torque and the shortfall residual, and reports the actual achievable torque and the shortfall residual to the coordination controller 1010. The coordination controller 1010 then performs a second torque allocation according to the actual achievable torque and the shortfall residual of each wheel, generates the final wheel-end target total torque of each wheel and sends it to the wheel-end node 1020 of each wheel. Each wheel-end node 1020 generates the final regenerative braking torque and the final EMB friction braking torque according to the final wheel-end target total torque, and sends them to the motor controller and the EMB actuator respectively.

[0121] In the above manner, the braking force distribution system provided in this embodiment can realize the braking force distribution method based on the distributed braking drive control architecture as described in any of the aforementioned method embodiments. By coordinating the closed-loop interaction between the controller and each wheel-end node, the dynamic differences between the regenerative braking capability and EMB friction braking capability of each wheel end are considered in real time. This allows the residual deficit caused by insufficient capability of a single wheel to be recoordinated and distributed at the vehicle level, avoiding the loss of braking force due to insufficient capability of a single wheel, and improving the consistency of vehicle braking response and the adaptability of braking force distribution.

[0122] This application also provides an electronic device, such as... Figure 11As shown, the electronic device includes at least one processor 111 and at least one memory 112. The at least one memory 112 stores program information. After reading the program information, the at least one processor 111 executes the braking force distribution method based on a distributed braking drive control architecture as described in any of the above method embodiments. The device may further include an input device 113 and an output device 114. The processor 111, memory 112, input device 113, and output device 114 can be communicatively connected. The memory 112, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules. The processor 111 executes various functional applications and data processing by running the non-volatile software programs, instructions, and modules stored in the memory 112, thereby implementing the braking force distribution method based on a distributed braking drive control architecture provided in any of the above embodiments. The memory 112 may include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a function; the data storage area may store data created according to the use of the braking force distribution method based on the distributed braking drive control architecture. Furthermore, memory 112 may include high-speed random access memory and non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some embodiments, memory 112 may optionally include memory remotely located relative to processor 111, and these remote memories may be connected via a network to a device performing a braking force distribution method based on a distributed brake drive control architecture. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof. Input device 113 may receive user clicks and generate signal inputs related to user settings and function control of the braking force distribution method based on a distributed brake drive control architecture. Output device 114 may include a display device such as a display screen. When the one or more modules are stored in memory 112 and are executed by the one or more processors 111, the braking force distribution method based on a distributed brake drive control architecture in any of the above method embodiments is performed.

[0123] As needed, the above technical solutions can be combined to achieve the best technical effect.

[0124] The above are merely the principles and preferred embodiments of this application. It should be noted that, for those skilled in the art, several other modifications can be made based on the principles of this application, and these modifications should also be considered within the scope of protection of this application.

Claims

1. A braking force distribution method based on a distributed braking drive control architecture, characterized in that, Applied to a coordination controller, the method includes: Obtain the total braking torque requirement of the entire vehicle; According to the ideal braking force distribution strategy, the total braking torque demand of the whole vehicle is distributed to each wheel to obtain the initial target wheel end total torque of each wheel and then sent to the wheel end node of each wheel. The actual achievable torque and the shortfall residual reported by each wheel-end node are obtained; the actual achievable torque and the shortfall residual are obtained by regenerative priority allocation of the initial target wheel-end total torque based on the upper limit of regenerative braking torque and the upper limit of EMB friction braking torque. Based on the actual achievable torque and residual deficit of each wheel, a secondary torque distribution is performed to generate the final target total torque at the wheel end of each wheel and distribute it to the wheel end node of each wheel.

2. The braking force distribution method based on a distributed braking drive control architecture according to claim 1, characterized in that, The process of obtaining the total braking torque requirement of the vehicle includes: Obtain the vehicle's actual speed and target speed; Based on the deviation between the actual vehicle speed and the target vehicle speed, a proportional-integral controller combined with a feedforward braking torque term is used to calculate the total braking torque requirement of the vehicle.

3. The braking force distribution method based on a distributed braking drive control architecture according to claim 2, characterized in that, The total braking torque requirement of the vehicle is calculated as follows: ； in, For the total braking torque requirement of the vehicle, It is a saturation function. This is the proportionality coefficient. This refers to the deviation between the actual vehicle speed and the target vehicle speed. The integral coefficient is... This is the feedforward braking torque term. This is the maximum braking torque of the entire vehicle.

4. The braking force distribution method based on a distributed braking drive control architecture according to claim 2, characterized in that: The feedforward braking torque term is determined based on at least one of the desired deceleration, gradient, or vehicle resistance.

5. The braking force distribution method based on a distributed braking drive control architecture according to claim 1, characterized in that, The initial target total wheel end torque of each wheel is obtained as follows: Obtain the current axle load transfer amount and determine the longitudinal distribution coefficient of each wheel based on the current axle load transfer amount; The total braking torque requirement of the entire vehicle is distributed to each wheel according to the longitudinal distribution coefficient of each wheel, so as to obtain the initial target total wheel end torque of each wheel.

6. The braking force distribution method based on a distributed braking drive control architecture according to claim 5, characterized in that, The steps for obtaining the initial target total wheel end torque for each wheel also include: The initial target wheel-end total torque is corrected based on the yaw torque correction term. The corrected initial target wheel-end total torque is expressed as follows: ； in, Let be the initial target total wheel end torque of the i-th wheel. Let be the longitudinal distribution coefficient for the i-th wheel. For the total braking torque requirement of the vehicle, This is the yaw torque correction term for the i-th wheel, which is zero when there is no stability control request.

7. The braking force distribution method based on a distributed braking drive control architecture according to claim 1, characterized in that, Perform secondary torque distribution, including: Calculate the total deficit of all wheels and the surplus capacity of each wheel; The total deficit is redistributed according to the proportion of surplus capacity of each wheel, and a yaw torque constraint is applied to the difference in compensation torque between the left and right wheels on the same axle to obtain the final target total torque at the wheel end of each wheel.

8. The braking force distribution method based on a distributed braking drive control architecture according to claim 7, characterized in that, The final target total torque at the wheel ends of each wheel is expressed as: ； ； ； ； ； ； in, Let be the final target total torque at the wheel end of the i-th wheel. Let be the initial target total wheel end torque of the i-th wheel. Let be the compensation torque for the i-th wheel. Let be the residual deficit of the i-th wheel. This represents the final target total torque at the wheel end of the left front wheel. This represents the final target total torque at the wheel end of the right front wheel. This represents the final target total torque at the left rear wheel end. This represents the final target total torque at the wheel end of the right rear wheel. The yaw torque threshold is the difference between the final target total torque at the wheel ends of the left and right wheels on the same axle. This represents the total shortfall. Let be the spare capacity of the i-th wheel. Let j be the spare capacity of the j-th wheel. Let be the upper limit of the regenerative braking torque for the i-th wheel. This represents the upper limit of the EMB friction braking torque for the i-th wheel.

9. The braking force distribution method based on a distributed braking drive control architecture according to claim 1, characterized in that, Perform secondary torque distribution, including: Construct the objective function: ； in, Let represent the final target total torque at the wheel end of the i-th wheel, used as an optimization variable. Let i be the regenerative braking torque of the i-th wheel. Let be the EMB friction braking torque of the i-th wheel, and , For the first i The upper limit of regenerative braking torque for each wheel; For friction braking weight, For regenerative braking weight, This is a stability penalty function; The constraints of the objective function include: Longitudinal braking force tracking constraint: The deviation between the total braking torque requirement of the vehicle and the set threshold shall not exceed. Wheel end capability limit constraints: ; For the first i The upper limit of EMB friction braking torque for each wheel; Yaw torque constraint: The difference between the final target total torque at the wheel ends of the left and right wheels on the same axle shall not exceed the yaw torque threshold. Solve the objective function to obtain the final target total torque at the wheel end of each wheel.

10. A braking force distribution method based on a distributed braking drive control architecture, applied to wheel-end nodes, characterized in that, include: Receive the initial target total wheel-end torque from the coordination controller; Based on the current regenerative braking torque limit and EMB friction braking torque limit of the corresponding wheel, the initial target wheel end total torque is regenerated preferentially allocated to determine the actual achievable torque and the shortfall residual, and the actual achievable torque and the shortfall residual are reported to the coordination controller. The final target total wheel-end torque is generated by the receiving coordination controller after secondary allocation based on the actual achievable torque and the deficit residual; Based on the final target total torque at the wheel end, the final regenerative braking torque and the final EMB friction braking torque are generated and sent to the motor controller and the EMB actuator, respectively.

11. The braking force distribution method based on a distributed braking drive control architecture according to claim 10, characterized in that, The steps to determine the actual achievable torque and the shortfall residual include: The regenerative braking torque and EMB demand torque are determined based on the upper limit of the regenerative braking torque and the initial target wheel-end total torque. When the EMB required torque exceeds the upper limit of the EMB friction braking torque, the sum of the upper limit of the regenerative braking torque and the upper limit of the EMB friction braking torque is determined as the actual achievable torque, and the difference between the initial target wheel end total torque and the actual achievable torque is determined as the deficit residual.

12. The braking force distribution method based on a distributed braking drive control architecture according to claim 11, characterized in that, The steps to determine the actual achievable torque and the shortfall residual also include: When the required torque of the EMB does not exceed the upper limit of the friction braking torque of the EMB, the initial target total torque at the wheel end is determined as the actual achievable torque, and the deficit residual is zero.

13. The braking force distribution method based on a distributed braking drive control architecture according to claim 10, characterized in that, The final regenerative braking torque and the final EMB friction braking torque are generated as follows: ； ； in, Let be the final regenerative braking torque of the i-th wheel. Let be the final target total torque at the wheel end of the i-th wheel. Let be the upper limit of the regenerative braking torque for the i-th wheel. Let be the final EMB friction braking torque of the i-th wheel.

14. The braking force distribution method based on a distributed braking drive control architecture according to claim 13, characterized in that, When generating the final regenerative braking torque and the final EMB friction braking torque, the following fault degradation logic is applied: If the regenerative braking system of the corresponding wheel fails, the upper limit of regenerative braking torque is set to zero, and a full friction braking strategy is output. If the corresponding wheel has an EMB failure, a safety mode request will be output and the target deceleration will be limited.

15. A coordination controller, characterized in that, The braking force distribution method based on a distributed braking drive control architecture as described in any one of claims 1-9 includes: Braking demand acquisition module, acquires the total braking torque demand of the vehicle; The initial allocation module allocates the total braking torque requirement of the vehicle to each wheel according to the ideal braking force allocation strategy, obtains the initial target wheel end total torque of each wheel, and sends it to the wheel end node of each wheel. The residual acquisition module acquires the actual achievable torque and the missing residual reported by each wheel end node for the corresponding wheel; the actual achievable torque and the missing residual are obtained by regenerative priority allocation of the initial target wheel end total torque based on the upper limit of regenerative braking torque and the upper limit of EMB friction braking torque. The secondary allocation module performs secondary torque allocation based on the actual achievable torque and residual deficit of each wheel, generating the final target total torque at the wheel end of each wheel and sending it to the wheel end node of each wheel.

16. A wheel end node, characterized in that, The method for performing the braking force distribution based on the distributed braking drive control architecture as described in any one of claims 10-14 includes: The receiving module receives the initial target total wheel-end torque sent by the coordination controller; The allocation and residual determination module performs regeneration priority allocation on the initial target wheel end total torque based on the upper limit of regenerative braking torque and the upper limit of EMB friction braking torque of the corresponding wheel at the current moment, determines the actual achievable torque and the missing residual, and reports the actual achievable torque and the missing residual to the coordination controller. The final target receiving module receives the final wheel-end target total torque generated by the coordination controller after secondary allocation based on the actual achievable torque and the deficit residual; The instruction generation module generates the final regenerative braking torque and the final EMB friction braking torque based on the final target total torque at the wheel end, and sends them to the motor controller and the EMB actuator, respectively.

17. A computer-readable storage medium, characterized in that, The storage medium stores program information, and after the computer reads the program information, it executes the steps of the braking force distribution method based on the distributed braking drive control architecture as described in any one of claims 1-14.

18. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instruction is executed by the processor, it implements the steps of the braking force distribution method based on the distributed braking drive control architecture as described in any one of claims 1-14.

19. An electronic device comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the braking force distribution method based on the distributed braking drive control architecture as described in any one of claims 1-14.

20. A braking force distribution system based on a distributed braking drive control architecture, characterized in that, It includes the coordination controller of claim 15 and a plurality of wheel-end nodes of claim 16, each wheel-end node corresponding to a wheel.

Images