Vehicle braking method, system, and storage medium

Abstract

This disclosure provides a vehicle braking method, system, and storage medium, relating to the field of vehicle control technology. The method includes: acquiring multi-dimensional operating parameters of a target vehicle related to overall vehicle braking control; determining the target vehicle's current electric braking force and mechanical braking force based on the multi-dimensional operating parameters; determining the target vehicle's current braking force compliance rate based on the electric and mechanical braking forces; and upon receiving a braking signal, selecting and implementing a braking force distribution strategy adapted to the current operating condition based on the target interval where the braking force compliance rate is currently located. This enables the target vehicle's electric braking actuator, mechanical braking actuator, and range extender actuator to adaptively adjust the braking force source based on the multi-dimensional operating parameters. The target interval is one of several preset intervals, with different intervals matched with different braking force distribution strategies. This method can identify the target vehicle's electric and mechanical braking forces in real time and actively distribute the braking force source.

Description

Technical Field

[0001] This disclosure belongs to the field of vehicle braking control technology, specifically relating to a vehicle braking method, system, and storage medium. Background Technology

[0002] In range-extended electric vehicles (REEVs), energy recovery and vehicle deceleration are typically achieved through a combination of electric and mechanical braking during braking. Electric braking uses a drive motor to generate reverse torque, converting kinetic energy into electrical energy that is fed back to the battery or consumed by a resistor, achieving efficient energy recovery and deceleration control. Mechanical braking provides braking force through the vehicle's pneumatic braking system. In this approach, the electric braking force is significantly affected by the battery's available charging power. When the battery's available charging power is lower than the electric braking feedback power, the electric braking force is forcibly limited. In this case, the vehicle relies excessively on mechanical braking, resulting in low energy recovery efficiency and potentially insufficient total braking force, leading to increased braking distance and potential braking safety hazards.

[0003] To address potential braking safety hazards, some related technologies have proposed solutions that allocate the ratio of electric braking to mechanical braking based on battery state, such as State of Charge (SOC). However, these solutions suffer from limitations in eliminating braking safety hazards due to factors such as diminished electric braking capacity under high SOC conditions, inability to quantify and monitor the total braking force of the vehicle in real time, and a lack of adaptability in braking force regulation. Furthermore, while these solutions utilize active charging of the power battery to dissipate energy when battery charging capacity is insufficient, this may lead to frequent charging and discharging of the power battery, accelerating battery aging and increasing energy consumption. Moreover, these solutions lack adaptability in braking control for different types of insufficient braking capacity scenarios because they cannot quantify the total braking force of the vehicle and lack control logic based on different risk levels for active coordination. Summary of the Invention

[0004] This disclosure provides a vehicle braking method, system, and storage medium, aiming to at least partially solve the technical problems of electric braking capacity decay under high SOC scenarios, the inability to quantify and monitor the total braking force of the vehicle in real time, and the lack of adaptability in braking force regulation.

[0005] At least one embodiment of this disclosure provides a vehicle braking method applied to a range-extended vehicle having a range extender actuator unit, an electric braking actuator unit, and a mechanical braking actuator unit, comprising:

[0006] Obtain the current multi-dimensional operating parameters of the target vehicle related to the vehicle braking control; The current electric braking force and mechanical braking force of the target vehicle are determined based on the multi-dimensional operating parameters. The current braking force compliance rate of the target vehicle is determined based on the electric braking force and the mechanical braking force; and... Upon receiving a braking signal, a braking force distribution strategy adapted to the current operating conditions is selected and implemented based on the target range where the braking force compliance rate is currently located. This enables the electric braking actuator, mechanical braking actuator, and range extender actuator of the target vehicle to adaptively adjust the braking force source based on the multi-dimensional operating parameters. The target range is one of a set of preset ranges, and different ranges are matched with different braking force distribution strategies.

[0007] The above solution offers the following technical advantages: Addressing the technical challenges of diminishing electric braking capacity under high SOC conditions, the inability to quantify and monitor the total braking force of the vehicle in real time, and the lack of adaptability in braking force control, this solution proposes a method that can identify the electric and mechanical braking forces of a target vehicle in real time and actively distribute multiple braking force sources, particularly suitable for heavy-duty range-extended electric vehicles. This method quantifies the braking force compliance rate through multi-dimensional operating parameters, effectively solving the problem of the inability to quantify and monitor the total braking force of the vehicle in real time. Furthermore, by adaptively controlling the braking force sources based on the real-time braking force compliance rate, the method can maintain the vehicle's braking capacity rigidly within a pre-set optimal range, avoiding the limitations of a single braking force distribution strategy. This effectively solves the problem of diminishing electric braking force under high SOC conditions in related technologies, significantly improving braking safety. In addition, this method allows for active discharge intervention and control through the range extender execution unit, broadening the operating range of electric braking and effectively addressing the lack of adaptability in braking force control.

[0008] In the method provided in at least one embodiment of this disclosure, the plurality of intervals include: The normal control range is used to characterize the braking capability of the target vehicle at a safe level. The first-level control range is used to characterize that the braking capability of the target vehicle has not reached a safe level and is higher than the preset vehicle reference braking force threshold. The secondary control range is used to characterize that the braking capability of the target vehicle is lower than the vehicle's baseline braking force threshold but higher than a preset risk threshold; and, The three-level control range is defined as the braking capability of the target vehicle being lower than the risk threshold.

[0009] The above scheme has the following technical effect: ensuring the graded control effect of braking force.

[0010] In at least one embodiment of the method provided in this disclosure, the step of selecting and operating a braking force distribution strategy adapted to the current operating condition based on the target range where the braking force achievement rate is currently located includes: Determine the current target range for the braking force compliance rate; In response to the target range being a normal control range, a preset first braking force distribution strategy is selected to operate, so that the target vehicle enters a first braking mode that prioritizes electric braking and is assisted by mechanical braking. In response to the target range being a first-level control range, a preset second braking force distribution strategy is selected to operate, so that the target vehicle enters a second braking mode that prioritizes increasing mechanical braking force and conditionally and actively discharges the range extender. In response to the target range being a secondary control range, a preset third braking force distribution strategy is selected and operated to cause the target vehicle to enter a third braking mode for unconditional active discharge of the range extender and mechanical braking; and, In response to the target range being a three-level control range, a preset fourth braking force distribution strategy is selected to operate, so that the target vehicle enters the fourth braking mode for full-power active discharge of the range extender and emergency mechanical braking.

[0011] The above scheme has the following technical effects: achieving the dual control objectives of maximizing energy recovery and prioritizing braking safety.

[0012] In at least one embodiment of the method provided in this disclosure, determining the current target range of the braking force compliance rate includes: In response to the braking force compliance rate being greater than a first set threshold, the target range is determined to be a normal control range; In response to the braking force compliance rate being greater than a second preset threshold and less than a first preset threshold, the target range is determined to be a first-level control range. In response to the braking force compliance rate being greater than a third preset threshold and less than a second preset threshold, the target range is determined to be a secondary control range; and, In response to the braking force compliance rate being less than the third preset threshold, the target range is determined to be a level three control range; The first set threshold, the second set threshold, and the third set threshold decrease sequentially.

[0013] The above scheme has the following technical effect: it provides a basis for selecting a graded control scheme for braking force.

[0014] In the method provided in at least one embodiment of this disclosure, the second braking force distribution strategy is configured as follows: The mechanical braking actuator is controlled to prioritize the pneumatic pressure boosting operation in order to increase the mechanical braking force output by the mechanical braking actuator; After performing the air pressure boosting operation, the braking force compliance rate of the target vehicle is determined again; Determine whether the re-determined braking force compliance rate reaches or exceeds the first set threshold; and, If the braking force compliance rate is not determined again to be above the first set threshold, when it is recognized that the driver has stepped on the brake and the required braking force of the target vehicle is greater than the current mechanical braking force, the range extender execution unit is controlled to enter the active discharge mode.

[0015] The above scheme has the following technical effects: achieving the dual control objectives of maximizing energy recovery and prioritizing braking safety.

[0016] In the method provided in at least one embodiment of this disclosure, the third braking force distribution strategy is configured as follows: The mechanical braking actuator is controlled to maintain the mechanical braking air pressure at a preset upper limit; and, The range extender actuator is controlled to unconditionally and actively discharge at a preset full power threshold until the braking force compliance rate is increased to above a second set threshold, thereby restoring the electric braking force of the target vehicle.

[0017] The above scheme has the following technical effects: achieving the dual control objectives of maximizing energy recovery and prioritizing braking safety.

[0018] In the method provided in at least one embodiment of this disclosure, the range-extended vehicle further includes an emergency braking execution unit, and the fourth braking force distribution strategy is configured as follows: The mechanical braking actuator is controlled to continuously perform the air pumping operation; Control the range extender execution unit to actively discharge at full power; When the mechanical braking actuator continuously performs the air pumping operation and the range extender actuator actively discharges at full power for a set duration, the braking force compliance rate of the target vehicle is determined again, and it is determined whether the re-determined braking force compliance rate has recovered to above the third set threshold; and, If the braking force compliance rate is again determined to be below the third set threshold, the vehicle is determined to have a braking malfunction, and a stop malfunction command is sent to the emergency braking execution unit to trigger an emergency stop.

[0019] The above scheme has the following technical effects: achieving the dual control objectives of maximizing energy recovery and prioritizing braking safety.

[0020] In at least one embodiment of the method provided in this disclosure, the range-extended vehicle further includes a power battery, a drive motor controlled by the electric braking actuator, a pneumatic braking system controlled by the mechanical braking actuator, and a range extender controlled by the range extender actuator. The multidimensional operating parameters include: Power battery parameters, including the current SOC and available charging power of the power battery; Active discharge parameters, including the current active discharge power of the range extender; The drive motor parameters include the current actual speed of the drive motor, the actual torque of the motor, and the peak torque of the motor. Air pressure braking system parameters, including the actual air pressure in the brake chamber of the air pressure braking system; and, Vehicle operating parameters, including vehicle speed, road condition parameters, and vehicle weight; Determining the current electric braking force and mechanical braking force of the target vehicle based on the multi-dimensional operating parameters includes: The motor efficiency is determined based on the actual motor speed and the actual motor torque. The electric braking force is determined based on the ratio of the available battery charging power to the actual motor speed, combined with the motor efficiency. The electric braking force does not exceed the peak torque of the motor. The electric braking force is positively correlated with the available battery charging power and the motor efficiency, and negatively correlated with the actual motor speed. The mechanical braking force is determined based on the actual air pressure in the brake chamber, wherein the mechanical braking force is positively correlated with the actual air pressure in the brake chamber; Determining the current braking force compliance rate of the target vehicle based on the electric braking force and the mechanical braking force includes: The total braking force of the target vehicle is generated based on the electric braking force and the mechanical braking force; and... The braking force compliance rate is generated based on the ratio of the total braking force to the vehicle weight.

[0021] The above solution has the following technical effect: it enables precise acquisition of vehicle braking force.

[0022] At least one embodiment of this disclosure also provides a vehicle braking system applied to a range-extended vehicle having a range extender actuator unit, an electric braking actuator unit, and a mechanical braking actuator unit, comprising: The acquisition unit is configured to acquire the current multi-dimensional operating parameters of the target vehicle related to the vehicle's braking control. The preprocessing unit is configured to determine the current electric braking force and mechanical braking force of the target vehicle based on the multi-dimensional operating parameters, and to determine the current braking force compliance rate of the target vehicle based on the electric braking force and the mechanical braking force; and, The control unit is configured to, upon receiving a braking signal, select and operate a braking force distribution strategy adapted to the current operating conditions based on the target interval where the braking force achievement rate is currently located, so that the electric braking actuator, mechanical braking actuator, and range extender actuator of the target vehicle can adaptively adjust the braking force source based on the multi-dimensional operating parameters. The target interval is one of a set of preset intervals, and different intervals are matched with different braking force distribution strategies.

[0023] At least one embodiment of this disclosure also provides a storage medium storing a program or instructions, wherein the program or instructions, when executed by a processor, implement the steps of the method provided in any embodiment of this disclosure.

[0024] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 A schematic diagram illustrating the components of a powertrain system for a range-extended vehicle; Figure 2 A flowchart of a vehicle braking method provided in at least one embodiment of this disclosure; Figure 3 A flowchart illustrating the electric braking force and mechanical braking force determination scheme provided for at least one embodiment of this disclosure; Figure 4 Flowchart of a braking force compliance rate determination scheme provided for at least one embodiment of this disclosure; Figure 5 A flowchart of a braking force graded control scheme provided in at least one embodiment of this disclosure; Figure 6 A flowchart of a first braking force distribution strategy provided for at least one embodiment of this disclosure; Figure 7 A flowchart of a second braking force distribution strategy provided for at least one embodiment of this disclosure; Figure 8 A flowchart of a third braking force distribution strategy provided for at least one embodiment of this disclosure; Figure 9 A flowchart of a fourth braking force distribution strategy provided for at least one embodiment of this disclosure; Figure 10Example flowchart of a vehicle braking method provided for at least one embodiment of this disclosure; Figure 11 A structural block diagram of a vehicle braking system provided for at least one embodiment of this disclosure; Figure 12 A schematic diagram illustrating the composition of a mechanical braking actuator provided in at least one embodiment of this disclosure; Figure 13 A structural block diagram of a program product provided for at least one embodiment of this disclosure.

[0027] Figure label: 1- Vehicle controller; 2- Range extender actuator; 3- Range extender; 4- Electric brake actuator; 5- Drive motor; 6- Mechanical brake actuator; 7- Mechanical brake system; 8- Power battery; 9- Emergency brake actuator; 101- Acquisition unit; 102- Preprocessing unit; 103- Control unit; 104a- Master brake valve; 104b- First electronically controlled valve; 104c- Second electronically controlled valve; 104d- Brake branch valve; 105- Brake pedal; 106- Air tank; 107- Front and rear axle brake chambers; 201- Processor; 202- Memory; 203- Input device; 204- Output device. Detailed Implementation

[0028] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments. It should be particularly noted that the following embodiments are for illustrative purposes only and do not limit the scope of the disclosure. Similarly, the following embodiments are only some, not all, embodiments of the present disclosure, and all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this disclosure.

[0029] The terms "first," "second," and "third" used in the embodiments of this disclosure are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first," "second," and "third" may explicitly or implicitly include at least one of that feature.

[0030] In the description of this disclosure, "multiple" means at least two, such as two or three, unless otherwise expressly and specifically limited.

[0031] In this disclosure, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0032] The terms “comprising” and “having”, and any variations thereof, used in this disclosure are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or components inherent to such processes, methods, products, or devices.

[0033] The term "range-extended vehicle" used in this disclosure is also referred to as a range-extended vehicle.

[0034] The term "range extender" in embodiments of this disclosure includes engines and generators.

[0035] The term "range extender execution unit" in the embodiments of this disclosure includes, but is not limited to, a range extender controller, which is used to control the range extender, switch the operating mode of the range extender according to instructions, such as conventional power generation mode or active discharge mode, control the speed and load of the range extender, and realize the regulation of active discharge power.

[0036] The term "electric braking actuator" in the embodiments of this disclosure includes, but is not limited to, a drive motor controller, which is used to control the electric braking system and achieve precise output of electric braking force by adjusting the regenerative braking torque of the drive motor.

[0037] The term "mechanical braking actuator" in the embodiments of this disclosure includes, but is not limited to, at least one of a brake air compressor, a brake valve group, or a brake air chamber, which is used to control the mechanical braking system, adjust the brake air pressure of the mechanical braking system according to instructions, and output the corresponding mechanical braking force.

[0038] The term "emergency braking actuator" in this disclosure includes, but is not limited to, a vehicle-specific emergency relay valve that triggers emergency braking upon receiving a stop fault command.

[0039] The term "pneumatic braking system" in this disclosure, also known as a pneumatic braking system, is a type of mechanical braking system used to provide mechanical braking force to a vehicle. It intervenes when regenerative braking capacity is insufficient or when emergency braking is required, and works in conjunction with electric braking to decelerate or stop the vehicle.

[0040] The term "vehicle controller" (VCU) used in this disclosure is primarily responsible for coordinating and managing the vehicle's powertrain, energy distribution, and overall vehicle control.

[0041] The term "battery management system" in this disclosure is abbreviated as BMS.

[0042] In this disclosure, the term "battery state of charge" is abbreviated as SOC, also known as the current remaining percentage of battery charge.

[0043] The term "battery available charging power" in the embodiments of this disclosure, also known as battery allowable charging power, refers to the maximum charging power allowed under the current SOC state, which changes dynamically with factors such as battery temperature and aging.

[0044] In this disclosure, the term "active discharge" refers to switching the engine to a power-consuming braking mode by adjusting the engine valves and fuel injection strategy.

[0045] In the embodiments of this disclosure, the term "electric braking" refers to a braking method that uses a drive motor to reverse and generate reverse torque, converting kinetic energy into electrical energy to be fed back to the power battery or a power resistor, thereby achieving efficient energy recovery and deceleration control.

[0046] In this disclosure, the term "mechanical braking" refers to a braking method in which a vehicle pneumatic braking system provides mechanical braking force by using compressed air to drive the braking device.

[0047] The technical approach involved in this disclosure will be briefly described below.

[0048] Figure 1 This is a schematic diagram illustrating the components of a powertrain system for a range-extended electric vehicle. Figure 1As shown, the power system of a range-extended vehicle includes a vehicle controller 1, a range extender execution unit 2, a range extender 3, an electric braking execution unit 4, a drive motor 5, a mechanical braking execution unit 6, a mechanical braking system 7, a power battery 8, and an emergency braking execution unit 9. The range extender 3 includes an engine and a generator. The mechanical braking system 7 can be a pneumatic braking system or a hydraulic braking system. The vehicle controller 1 is connected to the range extender execution unit 2, the electric braking execution unit 4, the mechanical braking execution unit 6, and the emergency braking execution unit 9. The range extender execution unit 2 is connected to the range extender 3, the electric braking execution unit 4 is connected to the drive motor 5, the mechanical braking execution unit 6 is connected to the mechanical braking system 7, and the drive motor 5 is connected to the power battery 8. The emergency braking execution unit 9 can be a vehicle-specific emergency relay valve. All components operate collaboratively according to the instructions of the vehicle controller to jointly complete the power regulation and braking force distribution during the braking process.

[0049] To address the technical problems of diminishing electric braking capacity under high SOC scenarios, the inability to quantify and monitor the total braking force of the vehicle in real time, and the lack of adaptability in braking force regulation in related technologies, this disclosure proposes a method that can identify the electric and mechanical braking forces of a target vehicle in real time and actively distribute multiple braking force sources, especially suitable for heavy-duty range-extended electric vehicles. This method quantifies the braking force compliance rate through multi-dimensional operating parameters, effectively solving the technical problem of the inability to quantify and monitor the total braking force of the vehicle in real time in related technologies. Furthermore, based on the real-time braking force compliance rate, adaptive regulation of the braking force sources can maintain the vehicle's braking capacity rigidly within a pre-set optimal range, avoiding the limitations of a single braking force distribution strategy. This effectively solves the problem of electric braking force attenuation under high SOC scenarios in related technologies, significantly improving braking safety. In addition, this method allows for active discharge intervention and regulation through the range extender execution unit, broadening the working range of electric braking and effectively solving the technical problem of the lack of adaptability to complex operating conditions in braking force regulation.

[0050] Based on this, the method disclosed herein takes maximizing energy recovery and prioritizing braking safety as its core objectives, and is based on the braking capability compliance rate. η The interval division integrates electric braking, mechanical braking and range extender active discharge functions to achieve adaptive control of braking force source, and establishes a full-process braking safety assurance system of real-time monitoring, hierarchical control and fault handling of braking force.

[0051] Based on this, the controller executing the method of this disclosure pre-stores the following parameters: the electric braking force curve of the drive motor, the mechanical braking force-air pressure mapping table, and the vehicle's reference braking force threshold. This method, through quantitative calculation of the braking capability compliance rate, can maintain the total braking force rigidity of the vehicle above 70% of the vehicle's reference braking force threshold. Addressing the issue of electric braking fade under high SOC scenarios, it actively restores electric braking force through active discharge from the range extender, solving the safety shortcomings of the passive mechanical braking system in related technologies. It is particularly suitable for the braking safety requirements of heavy-duty range-extended electric vehicles, significantly improving braking safety under extreme conditions.

[0052] Based on this, the method disclosed herein expands the working range of electric braking by prioritizing electric braking and controlling the range of active discharge of the range extender. In high SOC scenarios, there is no need to limit the intervention of electric braking in advance, which improves the efficiency of braking energy recovery and maximizes the energy recovery efficiency. This avoids limiting electric braking in advance to prevent braking failure, thereby achieving efficient energy recovery in a wider range of operating conditions and adapting to the braking safety requirements of heavy-duty range-extended electric vehicles.

[0053] Based on this, the disclosed braking force graded control scheme divides the line into four levels according to the braking force compliance rate, with each level corresponding to a different control range. From energy recovery in the normal control range, to prioritizing the enhancement of mechanical braking force in the first-level control range, unconditional discharge in the second-level control range, and emergency stopping in the third-level control range, it takes into account both energy recovery during normal driving and braking safety in extreme scenarios, avoiding the limitations of a single strategy. This enhances the adaptability of the braking force graded control scheme to various range-extended vehicles with complex risk conditions.

[0054] Based on this, this disclosure introduces a fault handling mechanism on the basis of graded adaptive control of braking force to diagnose braking faults. It can promptly identify abnormalities in the braking system, limit the vehicle's abnormal driving conditions, protect the safety of the driver and the vehicle, and enhance the traceability of faults.

[0055] Figure 2 This is a flowchart illustrating a vehicle braking method according to at least one embodiment of the present disclosure. The method is applied to range-extended vehicles, i.e., target vehicles, having a range extender actuator unit, an electric braking actuator unit, and a mechanical braking actuator unit, and is particularly suitable for heavy-duty range-extended electric vehicles. The range extender actuator unit includes at least a range extender control component, such as a range extender controller, and may further integrate a range extender. The electric braking actuator unit includes at least a drive motor control component, such as a drive motor controller, and may further integrate a drive motor. The mechanical braking actuator unit includes at least a mechanical braking control component, such as a brake air compressor, a brake valve assembly, or a brake chamber, and may further integrate a mechanical braking system. Figure 2 As shown, the method may include the following steps S10-S40 to achieve the vehicle braking function.

[0056] Step S10: Obtain the current multi-dimensional operating parameters of the target vehicle related to the vehicle braking control.

[0057] Step S20: Determine the current electric braking force (also known as electric braking capability) and mechanical braking force (also known as mechanical braking capability) of the target vehicle based on multi-dimensional operating parameters.

[0058] Step S30: Determine the current braking force compliance rate (also known as braking capacity compliance rate) of the target vehicle based on electric braking force and mechanical braking force.

[0059] Step S40: After receiving the braking signal, select and run a braking force distribution strategy that is compatible with the current operating conditions based on the target interval where the braking force compliance rate is currently located. This enables the electric braking actuator, mechanical braking actuator, and range extender actuator of the target vehicle to adaptively adjust the braking force source based on multi-dimensional operating parameters. The target interval is one of multiple preset intervals, and different intervals are matched with different braking force distribution strategies.

[0060] It should be noted that the multi-dimensional operating parameters, electric braking force, mechanical braking force, and braking force compliance rate are all real-time results. Different interval matching employs different braking force distribution strategies to maintain the total braking force rigidity of the vehicle above the vehicle's baseline braking force threshold, ultimately achieving the goal of maximizing energy recovery and prioritizing braking safety. Steps S10-S30 are, but are not limited to, executed throughout the entire period after the vehicle is powered on, while step S40 is executed after receiving a braking signal. The braking force source during braking includes at least one of the electric braking actuator, mechanical braking actuator, and range extender actuator.

[0061] In the above scheme, this disclosure does not limit the type of multi-dimensional operating parameters in step S10 or the method of obtaining them. In application scenarios, in addition to the scheme described in the following embodiments, it may further include one or more parameters among braking request deceleration, current operating status of the range extender, and operating temperature of the braking system. These parameters can be read from the corresponding sensor or controller unit via the vehicle's built-in CAN bus, without the need for additional hardware acquisition devices. When the system executes step S10, it can automatically select the corresponding operating parameter type and acquisition path according to the actual vehicle configuration and control requirements to ensure that the acquired parameters can meet the calculation requirements of electric braking force, mechanical braking force, and braking force compliance rate, as well as the braking force control requirements.

[0062] In the above scheme, this disclosure does not limit the scheme for determining the electric braking force and mechanical braking force in step S20. In application scenarios, in addition to the schemes described in the following embodiments, the electric braking force and mechanical braking force can also be directly obtained by querying a pre-constructed calibration mapping table. The calibration mapping table pre-stores the correspondence between different operating parameter ranges and the corresponding proportions of electric braking force and mechanical braking force. The allocation result can be quickly obtained by directly looking up the table without performing complex calculations, which can reduce the computational load of the vehicle controller and improve the response speed of braking force distribution. When the system executes step S20, it can select an appropriate electric braking force and mechanical braking force determination scheme according to the actual vehicle configuration and the actual application scenario of the vehicle to ensure that the calculation efficiency and control accuracy of braking force distribution meet the vehicle braking requirements, adapt to vehicle controller hardware with different computing performance, and ensure the timeliness and safety of the entire braking force distribution process.

[0063] In the above scheme, this disclosure does not limit the method for determining the braking force compliance rate in step 30. In application scenarios, in addition to the scheme described in the following embodiments, the braking force compliance rate can also be directly determined by a preset threshold comparison rule. Based on the design parameters and safety calibration results of the vehicle braking system, the minimum compliance thresholds for the electric braking system and the mechanical braking system under different operating conditions are set in advance. The actual braking capacity parameters detected are directly compared with the preset thresholds to complete the determination, which can also simplify the determination process and reduce the amount of calculation by the controller. When the system executes step S30, it can select an appropriate braking force compliance rate determination scheme according to its own controller computing performance and braking system configuration type to ensure the efficiency and accuracy of braking capacity determination, meet the braking control requirements of different vehicle models, and ensure the reliability and safety of the vehicle braking process.

[0064] In the above scheme, this disclosure does not limit the braking force grading control scheme in step 40. In application scenarios, in addition to the scheme described in the following embodiments, it is also possible to further combine vehicle type, common driving scenarios, and braking system hardware parameters to pre-divide the electric braking force distribution interval and calibrate the corresponding distribution coefficient. The braking force distribution is completed directly by matching the corresponding distribution coefficient according to the calculated braking force compliance rate, without the need for additional calculation adjustments. This can further improve the response speed of braking force distribution, adapt to low-end vehicle controllers with limited computing performance, reduce the complexity of the control process, and ensure the stability and reliability of the braking control process. When the system executes step 40, it can select a suitable braking force grading control scheme according to the actual application scenario of the vehicle, reasonably divide the interval and configure the optimized braking force distribution strategy for each interval to ensure the goal of maximizing energy recovery and prioritizing braking safety.

[0065] Some embodiments of this disclosure also provide systems, storage media, and program products corresponding to the methods described above.

[0066] The method provided by at least one embodiment of this disclosure is applicable to any existing application scenario of range-extended vehicles that requires improved braking safety. For example, in urban road conditions where range-extended vehicles need to brake frequently when driving with a depleted battery, the method of this disclosure can recover as much kinetic energy as possible during braking and convert it into electrical energy for storage, while ensuring braking smoothness and safety. This improves the overall vehicle range and reduces wear on mechanical braking components, extending their service life. For onboard controllers with low computing power, braking force distribution can also be quickly completed through a pre-calibrated interval allocation strategy, without the need for complex iterative calculations, ensuring real-time stable operation of the control process and preventing braking risks caused by control lag.

[0067] In some embodiments, Figure 2 Based on this scheme, to provide precise data support for braking capacity calculation and control strategies, the range-extended vehicle also includes a power battery, a drive motor controlled by an electric braking actuator, a pneumatic braking system controlled by a mechanical braking actuator, and a range extender controlled by a range extender actuator. Furthermore, multi-dimensional operating parameters include power battery parameters, active discharge parameters, drive motor parameters, pneumatic braking system parameters, and overall vehicle operating parameters. Power battery parameters further include the current SOC of the power battery and the battery's available charging power. Active discharge parameters further include the current active discharge power of the range extender. Drive motor parameters further include the current actual motor speed, actual motor torque, and peak motor torque. Pneumatic braking system parameters further include the actual air pressure in the brake chambers of the pneumatic braking system and the brake pedal opening signal. Overall vehicle operating parameters include vehicle speed, road condition parameters, and vehicle weight. Road condition parameters include the current road slope and road surface adhesion coefficient. By combining the aforementioned multi-dimensional operating parameters, the maximum braking torque that the vehicle can provide under different braking methods can be accurately calculated. Combined with the total braking torque required by the vehicle at present, the distribution of multi-source braking force, including engine cylinder braking, mechanical braking, and energy recovery braking, can be dynamically adjusted. Under the premise of ensuring braking safety, energy recovery efficiency can be maximized, while reducing wear on mechanical braking components, extending the service life of components, and avoiding the impact of overcharging of the power battery on its service life. This ensures the reliability and economy of the braking process of the range-extended vehicle.

[0068] In some embodiments, Figure 2 Based on the proposed solution, to accurately determine the electric braking capability, the electric braking force can be obtained from the electric braking force curve of the drive motor pre-stored in the vehicle controller (VCU). This electric braking force curve is based on the actual motor speed. As the independent variable and using electric braking force As the dependent variable, and , This indicates the peak torque of the motor.

[0069] In some embodiments, Figure 2 Based on the proposed solution, to accurately determine the mechanical braking capability, the mechanical braking force can be obtained through a mechanical braking force-air pressure mapping table pre-stored in the vehicle control unit (VCU). Specifically, when the brakes are not applied, the current pressure of the air reservoir is first read. In other words, the available gas supply pressure is determined by adjusting the mechanical braking force versus the current pressure of the gas storage tank. The mapping table obtains the original mechanical braking force, and is further corrected by parameters such as brake pad thickness and temperature. The correction scheme can be obtained through experiments.

[0070] Figure 3 A flowchart illustrating the electric braking force and mechanical braking force determination scheme provided for at least one embodiment of this disclosure. Figure 2 Based on the scheme, in order to accurately determine the capabilities of electric braking and mechanical braking, step S20 may further include the following sub-steps S201-S203.

[0071] Sub-step S201: Determine the motor efficiency based on the actual motor speed and the actual motor torque.

[0072] Sub-step S202: Determine the electric braking force based on the ratio of the battery's available charging power to the motor's actual speed and the motor's efficiency. The electric braking force shall not exceed the motor's peak torque. The electric braking force is positively correlated with the battery's available charging power and the motor's efficiency, and negatively correlated with the motor's actual speed.

[0073] Sub-step S203: Determine the mechanical braking force based on the actual air pressure in the brake chamber, wherein the mechanical braking force is positively correlated with the actual air pressure in the brake chamber.

[0074] The motor efficiency varies with the actual motor speed and actual motor torque. Sub-steps S201-S203 can precisely determine the magnitude of the electric braking force and the mechanical braking force.

[0075] In some embodiments, Figure 3 Based on the solution, in order to quickly obtain the motor efficiency, the motor efficiency in sub-step S201 can be obtained by looking up a table. The relationship table between the motor efficiency and the actual motor speed and the actual motor torque is pre-calibrated and stored in the vehicle controller. After obtaining the current actual motor speed and the actual motor torque, the corresponding motor efficiency can be quickly matched by directly retrieving the relationship table.

[0076] In some embodiments, Figure 3 Based on the proposed scheme, in order to accurately determine the electric braking capability, sub-step S202 calculates the real-time electric braking force using the following formula. :

[0077] In the formula, Indicates the battery's available charging power. Indicates motor efficiency. This indicates the actual speed of the motor.

[0078] Furthermore, it enables electric braking force Forced satisfaction , This represents the peak torque of the motor. When the range extender actively discharges, it drives the engine through a generator to dissipate energy.

[0079] In some embodiments, Figure 3 Based on the scheme, in order to accurately determine the mechanical braking capability, sub-step S203 uses the real-time actual air pressure of the brake chamber. Retrieve the mechanical braking force-air pressure mapping table and interpolate to calculate the real-time mechanical braking force. The mechanical braking force-air pressure mapping table is a data table that has been pre-calibrated and stored in the vehicle control unit. This table uses the actual air pressure in the brake chamber as the data. As the independent variable and with mechanical braking force The dependent variable is used to adapt to the vehicle's air pressure braking characteristics. The actual air pressure in different brake chambers... The interpolated mechanical braking force is calculated for different maximum output mechanical braking forces. It also meets the requirement of not exceeding the upper limit of the torque of the mechanical braking system (also known as the maximum permissible output torque) under the current driving conditions.

[0080] Figure 4 A flowchart illustrating a braking force compliance rate determination scheme provided for at least one embodiment of this disclosure. Figure 2 or Figure 3 Based on the plan, such as Figure 4 As shown, step S30 may further include the following sub-steps S301-S302.

[0081] Sub-step S301: Generate the current total braking force of the target vehicle based on the electric braking force and the mechanical braking force.

[0082] Sub-step S302: Generate the braking force compliance rate based on the ratio of total braking force to vehicle weight.

[0083] The total braking force is related to both electric and mechanical braking forces, and their specific relationship can be obtained through calibration. The total braking force can also be further evaluated based on the electric and mechanical braking forces combined with vehicle speed and road condition parameters. The vehicle's baseline braking force can be obtained based on vehicle weight and braking regulations. Sub-steps S301-S302 allow for the rapid calculation of the vehicle's actual braking force compliance rate, providing an accurate basis for subsequent braking demand allocation. This avoids situations where insufficient total braking capacity leads to inadequate vehicle deceleration, improving the reliability and safety of the braking process. After calculating the braking force compliance rate, the subsequent braking force allocation strategy can be adjusted according to the range of the compliance rate to ensure that the overall vehicle braking effect meets the expected requirements.

[0084] In some embodiments, Figure 4 Based on the proposed solution, in order to quickly obtain the total braking force, the total braking force in sub-step S301... Calculate using the following formula:

[0085] The above scheme ensures that the calculated total braking force matches the actual state of the vehicle's current braking system.

[0086] In some embodiments, Figure 4 Based on the plan, in order to quickly obtain the braking force compliance rate, the braking force compliance rate in sub-step S302 is... Calculate using the following formula:

[0087] In the formula, This indicates the total weight of the vehicle.

[0088] This indicates the vehicle's baseline braking force threshold, which can be set. It accounts for 70% of the total vehicle weight. The reason is: when It accounts for more than 80% of the total vehicle weight, ensuring absolute safety; when It accounts for 70% to 80% of the total vehicle weight, meeting the vehicle's benchmark braking force; when These components account for 60% to 70% of the vehicle's weight, have relatively weak braking force, and pose a minor risk; when If the weight of a component accounts for less than 60% of the total vehicle weight, the braking force is too low, posing a significant risk.

[0089] In some embodiments, Figure 4Based on the scheme, to ensure the effectiveness of graded braking force control, step S40 includes multiple intervals: a conventional control interval, a first-level control interval, a second-level control interval, and a third-level control interval. The conventional control interval indicates that the target vehicle's braking capability is at a safe level, meaning the vehicle's braking is absolutely safe. The first-level control interval indicates that the target vehicle's braking capability has not reached a safe level but is higher than a preset vehicle baseline braking force threshold, meaning the vehicle's braking can meet the vehicle baseline braking force. The second-level control interval indicates that the target vehicle's braking capability is lower than the vehicle baseline braking force threshold but higher than a preset risk threshold, meaning the vehicle's braking force is weak and carries a small risk. The third-level control interval indicates that the target vehicle's braking capability is lower than the risk threshold, meaning the vehicle's braking force is too low and carries a significant risk.

[0090] Figure 5 A flowchart illustrating a braking force grading control scheme provided for at least one embodiment of this disclosure. Figure 2-4 Based on any one of the schemes, in order to achieve the dual control objectives of maximizing energy recovery and prioritizing braking safety, such as Figure 5 As shown, step S40 may further include the following sub-steps S401-S405.

[0091] Sub-step S401: Determine the current target range for the braking force compliance rate.

[0092] Sub-step S402: In response to the target range being a normal control range, select the preset first braking force distribution strategy to operate, so that the target vehicle enters the first braking mode that prioritizes electric braking and is assisted by mechanical braking.

[0093] Sub-step S403: In response to the target range being a first-level control range, a preset second braking force distribution strategy is selected to operate, so that the target vehicle enters a second braking mode that prioritizes increasing mechanical braking force and conditionally and actively discharges the range extender.

[0094] Sub-step S404: In response to the target range being a secondary control range, a preset third braking force distribution strategy is selected to operate, so that the target vehicle enters the third braking mode for unconditional active discharge of the range extender and mechanical braking.

[0095] Sub-step S405: In response to the target range being a three-level control range, select the preset fourth braking force distribution strategy to operate, so that the target vehicle enters the fourth braking mode for full-power active discharge of the range extender and emergency mechanical braking.

[0096] The process involves sub-steps S101-S103, which determine the braking force compliance rate and match and switch the corresponding braking force distribution strategy. This allows for dynamic adjustment of the braking scheme based on the real-time status of the electric braking capability. While ensuring braking safety and meeting requirements, it maximizes energy recovery efficiency. When the electric braking capability is insufficient, the range extender actively discharges in conjunction with mechanical braking to supplement the braking force, meeting the braking requirements under different operating conditions. Finally, corresponding to different control ranges, the braking mode is gradually adjusted as the degree of insufficient braking force increases. Upon reaching the third-level control range, the fourth braking mode is triggered, which uses the range extender to actively discharge at full power in conjunction with emergency mechanical braking to ensure vehicle braking safety and complete the braking control process.

[0097] In some embodiments, Figure 5 Based on the scheme, in order to match different intensity braking strategies according to the vehicle's current actual braking capacity, sub-step S401 may further include the following sub-steps S401a-S401d.

[0098] Sub-step S401a: In response to the braking force compliance rate being greater than the first set threshold, the determination interval is the normal control interval.

[0099] Sub-step S401b: In response to the braking force compliance rate being greater than the second set threshold and less than the first set threshold, the determination interval is the first-level control interval.

[0100] Sub-step S401c: In response to the braking force compliance rate being greater than the third set threshold and less than the second set threshold, the determination interval is the secondary control interval.

[0101] Sub-step S401d: In response to the braking force compliance rate being less than the third set threshold, the determination interval is the third-level control interval.

[0102] The first, second, and third set thresholds decrease sequentially. The selection of these thresholds can refer to relevant national standards, such as GB 7258-2017. Through sub-steps S401a-S401d, the braking process is divided into different control ranges based on different operating conditions. This allows for matching different braking intensities to the vehicle's current actual braking capacity, avoiding brake fade caused by over-braking and ensuring driving safety from insufficient braking force. It also provides a basis for subsequent braking force grading control schemes, ensuring braking safety and stability during long downhill driving.

[0103] As an exemplary implementation, the first threshold is set to 80%, the second threshold is set to 70%, and the third threshold is set to 60%.

[0104] Figure 6A flowchart illustrating a first braking force distribution strategy provided for at least one embodiment of this disclosure. Figure 5 Based on the existing scheme, in order to further achieve the dual control objectives of maximizing energy recovery and prioritizing braking safety, such as... Figure 6 As shown, the first braking force distribution strategy of sub-step S402 is configured to include the following sub-steps S402a-S402c.

[0105] Sub-step S402a: Control the electric braking actuator to prioritize its electric braking capability for vehicle braking in order to maximize the energy recovery of the power battery.

[0106] Sub-step S402b: When the required braking force of the target vehicle is greater than the current electric braking force, control the mechanical braking actuator to perform mechanical braking based on the difference between the required braking force and the electric braking force.

[0107] Sub-step S402c: Control the range extender execution unit to maintain normal power generation mode operation.

[0108] It should be noted that the required braking force can be obtained through the braking signal from the brake pedal.

[0109] Specifically, through sub-steps S402a-S402c, the basic logic of prioritizing electric braking and assisting mechanical braking is adopted within the normal control range. Electric braking capacity is prioritized to maximize energy recovery from the power battery, while the braking force is adjusted according to the driver's needs. At that time, the difference is supplemented by mechanical braking. The range extender maintains its normal operating state, generating electricity only according to the SOC demand of the power battery and not participating in active discharge. This setup maximizes energy recovery efficiency during braking while meeting the vehicle's braking requirements, without needing to adjust the range extender's existing operating state, avoiding additional control logic changes, reducing system control complexity, adapting to braking demands in normal driving scenarios, ensuring smooth braking while improving the vehicle's overall energy utilization efficiency.

[0110] Figure 7 A flowchart illustrating a second braking force distribution strategy provided for at least one embodiment of this disclosure. Figure 5 Based on the existing scheme, in order to further achieve the dual control objectives of maximizing energy recovery and prioritizing braking safety, such as... Figure 7 As shown, the second braking force distribution strategy of sub-step S403 is configured to include the following sub-steps S403a-S403d.

[0111] Sub-step S403a: Control the mechanical brake actuator to prioritize the pneumatic pressure boosting operation to increase the mechanical braking force output by the mechanical brake actuator.

[0112] Sub-step S403b: After performing the air pressure boosting operation, re-determine the target vehicle's braking force compliance rate.

[0113] Sub-step S403c: Determine whether the re-determined braking force compliance rate has reached or exceeded the first set threshold.

[0114] Sub-step S403d: If the braking force compliance rate is not determined again to be above the first set threshold, when it is identified that the driver has stepped on the brake and the required braking force of the target vehicle is greater than the current mechanical braking force, the range extender execution unit is controlled to enter the active discharge mode.

[0115] Specifically, through sub-steps S403a-S403d, the air pressure boosting operation is preferentially executed within the primary control range to control the brake air compressor in the pneumatic braking system to continuously operate, increasing the air pressure in the brake air reservoir or tank to the calibrated maximum value, thereby increasing the mechanical braking force by increasing the air pressure. By increasing air pressure, the mechanical braking force is increased to ensure that the total braking force reaches or exceeds the vehicle's baseline braking force threshold; if the air pressure is increased... If the threshold is not reached, conditional active discharge will be initiated only when the driver is detected to have applied the brakes and require braking force. The range extender is controlled to enter active discharge mode, with the discharge power adapted to the available discharge power of the battery. By actively discharging the range extender, the energy of the power battery is consumed, reducing the battery's state of charge (SOC) and increasing the battery's available charging power, thereby restoring electric braking capability. This setup maximizes energy recovery while ensuring braking safety meets target requirements. Within a range with sufficient mechanical braking capacity, the range extender discharges to enhance electric braking force, avoiding unnecessary mechanical brake wear and converting the kinetic energy of braking into electrical energy stored in the power battery, extending the vehicle's range. This also aligns with the control logic that prioritizes braking safety.

[0116] In some embodiments, Figure 7 Based on the scheme, in order to ensure the smoothness of vehicle power output during braking, the second braking force distribution strategy of sub-step S403 is configured to also include the following sub-step S403e.

[0117] Sub-step S403e: If the re-determined braking force compliance rate reaches or exceeds the first set threshold, or if the re-determined braking force compliance rate does not reach or exceeds the first set threshold but does not meet the requirement that the driver applies the brakes and the target vehicle's required braking force is greater than the current mechanical braking force, control the range extender execution unit to maintain the current operating mode.

[0118] By setting sub-step S403e, the range extender can maintain its current stable operating state when the mechanical braking capacity is sufficient to meet safety requirements. This eliminates the need to switch to active discharge mode, avoids control fluctuations caused by frequent mode switching, ensures the smoothness of vehicle power output, and does not affect braking safety, thus balancing braking safety and vehicle operation stability.

[0119] Figure 8 A flowchart illustrating a third braking force distribution strategy provided for at least one embodiment of this disclosure. Figure 5 Based on the existing scheme, in order to further achieve the dual control objectives of maximizing energy recovery and prioritizing braking safety, such as... Figure 8 As shown, the third braking force distribution strategy in sub-step S404 is configured to include the following sub-steps S404a and S404b.

[0120] Sub-step S404a: Control the mechanical braking actuator to maintain the preset upper limit of mechanical braking air pressure (also known as the maximum mechanical braking air pressure).

[0121] Sub-step S404b: Control the range extender execution unit to unconditionally and actively discharge and perform active discharge at a preset full power threshold until the braking force compliance rate is increased to above the second set threshold to end the unconditional active discharge, so as to restore the electric braking force of the target vehicle.

[0122] Specifically, through sub-steps S404a and S404b, in the secondary control range, unconditional active discharge is initiated. Regardless of whether the driver applies the brakes, the range extender is immediately controlled to enter full-load active discharge mode, rapidly reducing the SOC of the power battery until the battery's available charging power is increased to meet the requirements for restoring electric braking capability. η The braking pressure recovers to over 70%; simultaneously, it maintains the mechanical braking air pressure at its maximum value to ensure braking backup capability. This setup allows for rapid restoration of electric braking capacity in the secondary control range where electric braking is insufficient, maximizing energy recovery efficiency during braking. It also maintains sufficient mechanical braking reserve throughout the entire process, ensuring vehicle braking safety is not affected by the active discharge process, thus meeting the dual control requirements of maximizing energy recovery and prioritizing braking safety.

[0123] In the above scheme, the target vehicle has intermittent adjustments to air pressure and active discharge when the power is depleted for a long time.

[0124] Figure 9 A flowchart illustrating a fourth braking force distribution strategy provided for at least one embodiment of this disclosure. Figure 5 Based on this solution, in order to further achieve the dual control objectives of maximizing energy recovery and prioritizing braking safety, range-extended vehicles also include an emergency braking actuator, such as... Figure 9As shown, the fourth braking force distribution strategy in sub-step S405 is configured to include the following sub-steps S405a-S405d.

[0125] Sub-step S405a: Control the mechanical braking actuator to continuously perform the air pumping operation.

[0126] Sub-step S405b: Control the range extender execution unit to actively discharge at full power.

[0127] Sub-step S405c: When the mechanical brake actuator continuously performs the air pumping operation and the range extender actuator actively discharges at full power for a set time, the braking force compliance rate of the target vehicle is determined again, and it is determined whether the re-determined braking force compliance rate has recovered to above the third set threshold.

[0128] Sub-step S405d: If the braking force compliance rate is not determined to be above the third set threshold again, it is determined that the vehicle has a braking failure, and a stop failure command is sent to the emergency braking execution unit to trigger an emergency stop.

[0129] Specifically, through sub-steps S405a-S405d, within the three-level warning and control range, continuous inflation and maximum power active discharge are implemented. If the braking force compliance rate fails to recover above the third set threshold within a set time, a braking fault is reported, triggering an emergency stop and disallowing power output. This setting ensures the safety of passengers in the event of abnormal braking capacity that cannot be restored through conventional control, preventing the vehicle from continuing to drive with a braking fault and posing a safety risk. Furthermore, by first attempting to actively restore braking capacity before triggering an emergency stop, unnecessary interference with normal driving is minimized, balancing driving safety and traffic reliability.

[0130] As an exemplary implementation, in sub-step S405d, if the air pressure is continuously pumped and the maximum power is actively discharged for 5-10 seconds and cannot be restored to more than 60%, a braking system fault is reported, power output is not allowed, and an emergency stop is initiated.

[0131] In some embodiments, Figures 2-9 In order to achieve full-time monitoring of braking force after the vehicle is powered on, based on any of the schemes, the method also includes the following step S31.

[0132] Step S31: Generate and display monitoring information containing the electric braking force, mechanical braking force, and braking force compliance rate of different target vehicles.

[0133] Specifically, step S31 allows the driver to intuitively and promptly grasp the overall braking capacity of the vehicle during driving, detect slowly changing braking performance degradation in advance, facilitate advance maintenance planning, and intervene promptly when abnormal signs appear in the braking system, further improving the overall safety of vehicle operation. This achieves the monitoring of the braking force of the target vehicle.

[0134] In some embodiments, Figures 2-9 In order to further improve driving safety under abnormal braking scenarios, based on any of the solutions, the method also includes the following steps S41-sub-step S44.

[0135] Step S41: Monitor the braking force compliance rate.

[0136] Step S42: When the braking force compliance rate falls within the secondary control range, a warning different from the first level is triggered.

[0137] Step S44: In response to the braking force compliance rate falling within the three-level control range, a second-level warning, different from the first-level warning, is triggered, wherein the warning levels of the first-level warning and the second-level warning increase sequentially.

[0138] In particular, step S41-sub-step S44 can trigger different levels of warnings according to the different ranges of the braking force compliance rate, allowing the driver to intuitively perceive the current abnormality of the braking system and prepare for response in advance. The setting of graded warnings can also distinguish the severity of the fault and match different warning intensities accordingly, avoiding excessive warnings that interfere with driving and preventing delays in handling due to insufficient warnings, thus further improving driving safety in abnormal braking scenarios.

[0139] Figure 10 A flowchart illustrating an example vehicle braking method provided in at least one embodiment of this disclosure. Figure 10 As shown, the method includes the following steps: 1) After the vehicle is powered on, the electric braking force and mechanical braking force are monitored. The electric braking force is determined by the available charging power of the battery, the active discharge power, the actual speed of the motor and the maximum available torque of the motor. The mechanical braking force is determined by the front and rear axle air pressure, brake pad thickness and temperature of the air pressure braking system. 2) Determine the total braking force based on electric braking force and mechanical braking force, monitor the total braking force, and obtain the braking force compliance rate; 3) When the braking force compliance rate is greater than 80%, the first braking force distribution strategy is activated. In the first braking force distribution strategy, the braking priority of electric braking is greater than that of mechanical braking. The range extender operates in the normal power generation mode. The core control actions include: prioritizing the activation of electric braking to maximize energy recovery, and supplementing mechanical braking only when the required braking force is greater than the electric braking force, and maintaining normal air pressure in the brake air compressor. 4) When the braking force compliance rate is 70%~80%, the second braking force distribution strategy is activated. In this strategy, the braking priority of mechanical braking energy replenishment, the braking priority of electric braking, and the braking priority of range extender discharge decrease in that order. The range extender operates in conditional active discharge mode. The core control actions include: prioritizing the increase of air pressure, controlling the brake air compressor in the pneumatic braking system to work at full load, increasing the air pressure in the air tank to the maximum value, increasing the mechanical braking force, and, if the air pressure reaches the maximum value... η If the braking force is still less than 80%, conditional active discharge will be activated. The range extender will be actively discharged only when the required braking force is greater than the mechanical braking force. 5) When the braking force compliance rate is 60%~70%, the third braking force distribution strategy is activated. In the third braking force distribution strategy, the braking priority of the range extender discharging to restore electric braking is greater than the braking priority of mechanical braking. The range extender works in unconditional active discharge mode until the braking force compliance rate is restored to more than 70%. The core control actions include: maintaining the upper limit of mechanical braking air pressure, and unconditionally starting active discharge. Regardless of whether the driver applies the brakes, the range extender is immediately controlled to enter the full power active discharge mode to quickly reduce SOC and restore electric braking force, and forcibly increasing the priority of electric braking to reduce mechanical braking consumption. 6) When the braking force compliance rate is less than 60%, the fourth braking force distribution strategy is activated. In this strategy, the braking priority of emergency mechanical braking is higher than that of electric braking. The range extender operates in continuous full-power active discharge mode. The core control actions include: continuous full-power active discharge + maximum air pressure control, and if the above actions are executed for 10 seconds... η If the braking performance remains below 60%, it is determined to be a braking malfunction, and a forced stop command is sent to the emergency braking execution unit.

[0140] Among the above-mentioned braking force distribution strategies, if a change in the brake pedal opening is detected, the output ratio of electric braking and mechanical braking will be dynamically adjusted according to the current required braking force and the real-time available braking force. Under the premise of ensuring that the total braking force meets the braking requirements, the priority rules of the corresponding strategy will be executed.

[0141] Figure 11This is a structural block diagram of a vehicle braking system provided for at least one embodiment of the present disclosure. The system can be applied to range-extended vehicles having a range extender actuator unit, an electric braking actuator unit, and a mechanical braking actuator unit. Figure 11 As shown, the vehicle braking system 100 integrates an acquisition unit 101, a preprocessing unit 102, and a control unit 103.

[0142] The acquisition unit 101 is configured to acquire the current multi-dimensional operating parameters of the target vehicle related to the vehicle braking control. The preprocessing unit 102 is configured to determine the current electric braking force and mechanical braking force of the target vehicle based on multi-dimensional operating parameters, and to determine the current braking force compliance rate of the target vehicle based on the electric braking force and mechanical braking force.

[0143] The control unit 103 is configured to, upon receiving a braking signal, select and operate a braking force distribution strategy adapted to the current operating conditions based on the target interval where the braking force compliance rate is currently located, so that the electric braking actuator, mechanical braking actuator, and range extender actuator of the target vehicle can adaptively adjust the braking force source based on multi-dimensional operating parameters. Here, the interval is one of a number of preset intervals, and different intervals are matched with different braking force distribution strategies.

[0144] The specific execution methods of each unit in the above system embodiments have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0145] In some embodiments, Figure 11 Based on the scheme, the acquisition unit 101 can be implemented by corresponding sensors or receiving modules, the preprocessing unit 102 and the control unit 103 can be implemented by controllers with corresponding programs.

[0146] In some embodiments, Figure 11 Based on this solution, the vehicle braking system 100 also integrates an electric braking actuator, a mechanical braking actuator, and a range extender actuator. These three units execute control commands issued by the vehicle's core control module (e.g., the vehicle control unit (VCU) or a remote controller). The electric braking actuator can be a drive motor controller, adjusting the regenerative braking torque of the motor according to the braking force distribution strategy to achieve precise output of electric braking force. The mechanical braking actuator can be a brake air compressor, brake valve assembly, or brake chamber, adjusting the brake air pressure according to commands to output the corresponding mechanical braking force. The range extender actuator can be a range extender controller, switching the range extender's operating mode according to commands, entering either a conventional power generation mode or an active discharge mode, controlling the range extender's speed and load to achieve regulation of the active discharge power.

[0147] In some embodiments, the vehicle braking system 100 also integrates an emergency braking actuator. The emergency braking actuator may be a vehicle-specific emergency relay valve that triggers emergency braking upon receiving a stop fault command.

[0148] Figure 12 This is a schematic diagram illustrating the composition of a mechanical braking actuator provided in at least one embodiment of this disclosure. Figure 12 As shown, the mechanical braking actuator includes a master brake valve 104a, a first electrically controlled valve 104b, a second electrically controlled valve 104c, and brake caliper valves 104d, forming a brake valve assembly. The control terminal of the master brake valve 104a is connected to the brake pedal 105, the input terminal of the master brake valve 104a is connected to the output terminal of the first electrically controlled valve 104b, and the output terminal of the master brake valve 104a is connected to the input terminal of the brake caliper valve 104d. The control terminal of the first electrically controlled valve 104b is connected to the vehicle controller 1, and the input terminal of the first electrically controlled valve 104b is connected to the output terminal of the air tank 106. The control terminal of the second electrically controlled valve 104c is connected to the vehicle controller 1, the input terminal of the second electrically controlled valve 104c is connected to the output terminal of the air tank 106, and the output terminal of the second electrically controlled valve 104c is connected to the input terminal of the brake caliper valve 104d. The output terminal of the brake caliper valve 104d is connected to the front and rear axle brake chambers 107.

[0149] The active braking force distribution requires, based on the actual vehicle conditions and following the aforementioned strategy, a proportional distribution between electric and mechanical braking based on the total braking force demand transmitted from the foot brake opening. Decoupling the linear relationship between the foot brake opening and the brake valve opening is a prerequisite for realizing the system's function. Therefore, the decoupling control scheme is given here: After the brake pedal is depressed, when electric braking is present, the VCU receives the braking force demand and... Figures 2-10 In any given allocation scheme, the total braking force demand minus the portion borne by electric braking force, with the remaining portion requiring mechanical braking, is controlled by the vehicle control unit (VCU). The first electronically controlled valve 104b blocks the circuit of the master brake valve 104a, while the second electronically controlled valve 104c is opened and given a corresponding opening degree to achieve controllable mechanical braking force. Furthermore, when the brake pedal is depressed, in the event of a low-voltage electrical anomaly or an electric braking failure, the vehicle's braking force relies solely on mechanical braking. In this case, the first electronically controlled valve 104b (normally open) opens, and the second electronically controlled valve 104c (normally closed) closes, restoring pure mechanical braking controlled by the brake pedal and the master brake valve.

[0150] In some embodiments, Figure 11 or Figure 12 Based on the solution, the vehicle braking system 100 also integrates a fault module, which is configured to execute steps S41-S44 of the previous method embodiment to monitor the braking capability compliance rate in real time. η To determine the continuous state of the fault, a fault classification and determination mechanism should be established.

[0151] In some embodiments, the fault module is further configured to execute sub-steps S405c-S405d from the preceding method embodiments. For example, if the system performs control measures such as pressure boosting or active discharge, η If the failure rate remains below 60% for more than 10 seconds, it is determined to be a braking and stopping fault. The fault handling includes generating a fault code, immediately sending a stop command to the vehicle controller via the CAN bus, controlling the drive motor to stop outputting power, and simultaneously triggering the emergency braking function of the mechanical braking system.

[0152] In some embodiments, Figure 11 or Figure 12 Based on the proposed solution, the vehicle braking system also includes a device for visually displaying the braking system status and providing fault alarms. This device includes an instrument display screen and an audible and visual alarm unit. The instrument display screen shows the vehicle's current braking capability compliance rate in real time. η Electric braking capacity ratio, mechanical braking capacity ratio, power battery SOC, real-time air pressure of brake reservoir; audible and visual alarm unit in the current... η A yellow warning light is triggered when the level enters the 70%~80% range; a yellow warning light is triggered when the level is less than 60%. η When <70%, a yellow warning light and alarm sound will be triggered; when η If the braking force is less than 60%, it is considered a braking failure, triggering a red warning light and an urgent alarm sound. At the same time, a fault message "Insufficient braking force, please stop immediately" will pop up on the instrument display screen.

[0153] This disclosure also provides a storage medium storing a program or instructions that, when executed by a processor, implement the steps of the method embodiments described above.

[0154] This disclosure also provides a program product, such as... Figure 13 As shown, the program product includes one or more processors 201 and memory 202. Figure 13 Take a processor 201 as an example.

[0155] The controller may also include an input device 203 and an output device 204.

[0156] The processor 201, memory 202, input device 203, and output device 204 can be connected via a bus or other means. Figure 13 Taking the example of a connection between China and Israel via a bus.

[0157] Processor 201 can be a central processing unit (CPU), or it can be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or combinations of the above types of chips. The general-purpose processor can be a microprocessor or any conventional processor.

[0158] The memory 202, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as the program instructions / modules corresponding to the methods in the embodiments of this disclosure. The processor 201 executes various functional applications and data processing of the server by running the non-transitory software programs, instructions, and modules stored in the memory 202, thereby implementing the steps of the above-described method embodiments.

[0159] The memory 202 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created by the use of the processing device operated by the server. Furthermore, the memory 202 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory 202 may optionally include memory remotely located relative to the processor 201, and these remote memories can be connected to a network connection device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0160] Input device 203 can receive input digital or character information, and generate key signal inputs related to driver settings and function control of the server's processing unit. Output device 204 may include display devices such as a display screen.

[0161] One or more modules are stored in memory 202, and when executed by one or more processors 201, they perform actions such as... Figure 2 The method shown.

[0162] Those skilled in the art will understand that all or part of the processes in the above method embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), random access memory (RAM), flash memory (FM), hard disk drive (HDD), or solid-state drive (SSD), etc.; the storage medium can also include combinations of the above types of memory.

[0163] Although embodiments of the present disclosure have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present disclosure, and all such modifications and variations fall within the scope defined by the appended claims.

[0164] Although embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A vehicle braking method, applied to a range-extended vehicle having a range extender actuator unit, an electric braking actuator unit, and a mechanical braking actuator unit, characterized in that, include: Obtain the current multi-dimensional operating parameters of the target vehicle related to the vehicle braking control; The current electric braking force and mechanical braking force of the target vehicle are determined based on the multi-dimensional operating parameters. The current braking force compliance rate of the target vehicle is determined based on the electric braking force and the mechanical braking force. as well as, Upon receiving a braking signal, a braking force distribution strategy adapted to the current operating conditions is selected and implemented based on the target range where the braking force compliance rate is currently located. This enables the electric braking actuator, mechanical braking actuator, and range extender actuator of the target vehicle to adaptively adjust the braking force source based on the multi-dimensional operating parameters. The target range is one of a set of preset ranges, and different ranges are matched with different braking force distribution strategies.

2. The method according to claim 1, characterized in that, The plurality of intervals includes: The normal control range is used to characterize the braking capability of the target vehicle at a safe level. The first-level control range is used to characterize that the braking capability of the target vehicle has not reached a safe level and is higher than the preset vehicle reference braking force threshold. The secondary control range is used to characterize that the braking capability of the target vehicle is lower than the vehicle's baseline braking force threshold but higher than a preset risk threshold; and, The three-level control range is defined as the braking capability of the target vehicle being lower than the risk threshold.

3. The method according to claim 1 or 2, characterized in that, The step of selecting and implementing a braking force distribution strategy that is compatible with the current operating conditions based on the current target range of the braking force achievement rate includes: Determine the current target range for the braking force compliance rate; In response to the target range being a normal control range, a preset first braking force distribution strategy is selected to operate, so that the target vehicle enters a first braking mode that prioritizes electric braking and is assisted by mechanical braking. In response to the target range being a first-level control range, a preset second braking force distribution strategy is selected to operate, so that the target vehicle enters a second braking mode that prioritizes increasing mechanical braking force and conditionally and actively discharges the range extender. In response to the target range being a secondary control range, a preset third braking force distribution strategy is selected and operated to cause the target vehicle to enter a third braking mode for unconditional active discharge of the range extender and mechanical braking; and, In response to the target range being a three-level control range, a preset fourth braking force distribution strategy is selected to operate, so that the target vehicle enters the fourth braking mode for full-power active discharge of the range extender and emergency mechanical braking.

4. The method according to claim 3, characterized in that, Determining the current target range of the braking force compliance rate includes: In response to the braking force compliance rate being greater than a first set threshold, the target range is determined to be a normal control range; In response to the braking force compliance rate being greater than a second preset threshold and less than a first preset threshold, the target range is determined to be a first-level control range. In response to the braking force compliance rate being greater than a third preset threshold and less than a second preset threshold, the target range is determined to be a secondary control range; and, In response to the braking force compliance rate being less than the third preset threshold, the target range is determined to be a level three control range; The first set threshold, the second set threshold, and the third set threshold decrease sequentially.

5. The method according to claim 3, characterized in that, The second braking force distribution strategy is configured as follows: The mechanical braking actuator is controlled to prioritize the pneumatic pressure boosting operation in order to increase the mechanical braking force output by the mechanical braking actuator; After performing the air pressure boosting operation, the braking force compliance rate of the target vehicle is determined again; Determine whether the re-determined braking force compliance rate has reached or exceeded the first set threshold. as well as, If the braking force compliance rate is not determined again to be above the first set threshold, when it is recognized that the driver has stepped on the brake and the required braking force of the target vehicle is greater than the current mechanical braking force, the range extender execution unit is controlled to enter the active discharge mode.

6. The method according to claim 3, characterized in that, The third braking force distribution strategy is configured as follows: The mechanical braking actuator is controlled to maintain the mechanical braking air pressure at a preset upper limit. as well as, The range extender actuator is controlled to unconditionally and actively discharge at a preset full power threshold until the braking force compliance rate is increased to above a second set threshold, thereby restoring the electric braking force of the target vehicle.

7. The method according to claim 3, characterized in that, The range-extended vehicle also includes an emergency braking execution unit, and the fourth braking force distribution strategy is configured as follows: The mechanical braking actuator is controlled to continuously perform the air pumping operation; Control the range extender execution unit to actively discharge at full power; When the mechanical braking actuator continuously performs the air pumping operation and the range extender actuator actively discharges at full power for a set time, the braking force compliance rate of the target vehicle is determined again, and it is determined whether the re-determined braking force compliance rate has recovered to above the third set threshold. as well as, If the braking force compliance rate is again determined to be below the third set threshold, the vehicle is determined to have a braking malfunction, and a stop malfunction command is sent to the emergency braking execution unit to trigger an emergency stop.

8. The method according to claim 1 or 2, characterized in that, The range-extended vehicle further includes a power battery, a drive motor controlled by the electric braking actuator, a pneumatic braking system controlled by the mechanical braking actuator, and a range extender controlled by the range extender actuator. The multidimensional operating parameters include: Power battery parameters, including the current SOC and available charging power of the power battery; Active discharge parameters, including the current active discharge power of the range extender; The drive motor parameters include the current actual speed of the drive motor, the actual torque of the motor, and the peak torque of the motor. Air pressure braking system parameters, including the actual air pressure in the brake chamber of the air pressure braking system; and, Vehicle operating parameters, including vehicle speed, road condition parameters, and vehicle weight; Determining the current electric braking force and mechanical braking force of the target vehicle based on the multi-dimensional operating parameters includes: The motor efficiency is determined based on the actual motor speed and the actual motor torque. The electric braking force is determined based on the ratio of the available battery charging power to the actual motor speed, combined with the motor efficiency. The electric braking force does not exceed the peak torque of the motor. The electric braking force is positively correlated with the available battery charging power and the motor efficiency, and negatively correlated with the actual motor speed. The mechanical braking force is determined based on the actual air pressure in the brake chamber, wherein the mechanical braking force is positively correlated with the actual air pressure in the brake chamber; Determining the current braking force compliance rate of the target vehicle based on the electric braking force and the mechanical braking force includes: The total braking force of the target vehicle is generated based on the electric braking force and the mechanical braking force; and... The braking force compliance rate is generated based on the ratio of the total braking force to the vehicle weight.

9. A vehicle braking system, applied to a range-extended vehicle having a range extender actuator unit, an electric braking actuator unit, and a mechanical braking actuator unit, characterized in that, include: The acquisition unit is configured to acquire the current multi-dimensional operating parameters of the target vehicle related to the vehicle's braking control. The preprocessing unit is configured to determine the current electric braking force and mechanical braking force of the target vehicle based on the multi-dimensional operating parameters, and to determine the current braking force compliance rate of the target vehicle based on the electric braking force and the mechanical braking force. and, The control unit is configured to, upon receiving a braking signal, select and operate a braking force distribution strategy adapted to the current operating conditions based on the target interval where the braking force achievement rate is currently located, so that the electric braking actuator, mechanical braking actuator, and range extender actuator of the target vehicle can adaptively adjust the braking force source based on the multi-dimensional operating parameters. The target interval is one of a set of preset intervals, and different intervals are matched with different braking force distribution strategies.

10. A storage medium, characterized in that, The storage medium stores a program or instructions, wherein the program or instructions, when executed by a processor, implement the steps of the method as described in any one of claims 1 to 8.

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