Vehicle braking method, system, and storage medium

Abstract

The present disclosure provides a vehicle braking method, system and storage medium, relating to the technical field of vehicle control, wherein the method comprises: obtaining a current multi-dimensional state parameter of a target vehicle; determining whether the target vehicle is in a dangerous working condition of emergency braking but insufficient braking force based on the multi-dimensional state parameter; determining whether the electric braking capacity of a driving motor is limited when the target vehicle is in the dangerous working condition; controlling the booster to start the engine cylinder braking mode to actively discharge when the electric braking capacity is limited, and automatically regulating the active discharge power of the booster based on the current electric braking demand power of the target vehicle and the current battery available charging power of the power battery, so that the braking force meets the preset braking demand. The method can actively and accurately improve the vehicle braking force through engine cylinder braking when the target vehicle is in the dangerous working condition of emergency braking but insufficient braking force and the electric braking capacity is limited, effectively shortening the braking distance.

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] Range-extended vehicles use the drive motor for energy recovery during braking, which can easily lead to overcharging of the power battery or limited electric braking power, thus affecting the normal operation of the vehicle.

[0003] In related technologies, range-extended vehicles generally rely on a fixed SOC range to activate the range extender for active discharge. This approach fails to dynamically consider the real-time changes in the battery's available charging power caused by factors such as temperature, aging, and instantaneous load, which limits vehicle braking safety. When the actual battery charging power is lower than the electric braking power requirement, this method forces the electric braking force to be constrained, leading to an increased braking distance, especially under low temperature or high SOC conditions. When the battery's available charging power cannot meet the electric braking power requirement and the set SOC trigger threshold is not reached, this method cannot trigger active discharge, resulting in insufficient or only partial release of electric braking capacity, creating a braking performance blind spot.

[0004] The related technologies also suffer from rigid control logic, failing to combine multiple parameters such as brake pedal opening and vehicle deceleration to collaboratively determine emergency braking scenarios. This results in premature or delayed intervention of active discharge, which may waste energy, such as being mistakenly triggered during light braking, or may fail to respond, leading to braking failure.

[0005] The related technologies also suffer from insufficient economic viability. While actively charging the power battery consumes energy, it may lead to frequent charging and discharging, accelerating the aging of the power battery and increasing energy consumption. Summary of the Invention

[0006] This disclosure provides a vehicle braking method, system, and storage medium, aiming to at least partially solve the technical problems of limited vehicle braking safety, rigid control logic, and insufficient economy caused by the reliance on a fixed SOC range for active discharge of the range extender.

[0007] At least one embodiment of this disclosure provides a vehicle braking method applied to a range-extended vehicle having a power battery, a range extender, and a drive motor, comprising:

[0008] Obtain the current multidimensional state parameters of the target vehicle; Based on the multidimensional state parameters, it is determined whether the target vehicle is in a dangerous operating condition of emergency braking but insufficient braking force. When the target vehicle is in the dangerous operating condition, determine whether the electric braking capability of the drive motor is limited; and, When the electric braking capability is limited, the range extender is controlled to activate the engine cylinder braking mode for active discharge. The active discharge power of the range extender is automatically adjusted based on the current electric braking power demand of the target vehicle and the current available charging power of the power battery, so that the braking force meets the preset braking requirements.

[0009] The above solution offers the following technical advantages: Addressing the limitations in vehicle braking safety, rigid control logic, and insufficient fuel economy caused by relying on fixed SOC ranges for active discharge of the range extender, a dynamically coordinated control method for vehicle braking is proposed. This method intelligently identifies dangerous emergency braking situations with insufficient braking force based on the vehicle's multi-dimensional state parameters. Only under these dangerous conditions, when the electric braking capacity of the drive motor is limited—that is, within the braking efficiency blind zone of traditional electric braking schemes—is active and precise energy dissipation achieved through in-cylinder braking from the engine. This ensures accurate initiation of active discharge and effective consumption of feedback energy, thereby improving vehicle braking force and effectively shortening braking distance. Furthermore, this method determines the active discharge power of the range extender in real time based on the electric braking power demand and the current available charging power of the power battery. By dynamically coordinating and controlling the active discharge power, it balances vehicle braking safety and fuel economy. This ensures that electric braking force can intervene to effectively solve the problem of limited vehicle braking safety, while avoiding frequent charging and discharging of the power battery due to frequent intervention, effectively improving overall vehicle fuel economy and extending the lifespan of the power battery.

[0010] The method provided in at least one embodiment of this disclosure further includes: The multidimensional state parameters are monitored during active discharge of the range extender; Determine whether the multidimensional state parameters meet the preset engine in-cylinder braking mode exit conditions; and, When the multidimensional state parameters meet the engine in-cylinder braking mode exit condition, the range extender is controlled to exit the engine in-cylinder braking mode to end the active discharge.

[0011] The above solution has the following technical effects: it can exit the engine cylinder braking mode at the appropriate time to avoid affecting the vehicle's power output or causing unnecessary wear and tear on the vehicle's braking system.

[0012] In at least one embodiment of the method provided in this disclosure, the target vehicle includes a brake pedal, and the multidimensional state parameters include: Brake pedal opening, Vehicle deceleration, and Simultaneously satisfying the first duration where the brake pedal opening is greater than a preset opening threshold and the vehicle deceleration is continuously less than a preset deceleration threshold.

[0013] The above solution has the following technical effect: avoiding unnecessary damage to vehicle power system components.

[0014] In at least one embodiment of the method provided in this disclosure, determining whether the target vehicle is in a dangerous condition of emergency braking but insufficient braking force based on the multidimensional state parameters includes: Determine whether the following conditions are met simultaneously: the brake pedal opening is greater than the opening threshold, the vehicle deceleration is continuously less than the deceleration threshold, and the first duration is greater than a preset first time threshold; and... If so, the target vehicle is determined to be in the dangerous operating condition.

[0015] The above solution has the following technical effects: accurately identifying dangerous operating conditions where emergency braking is required but braking force is insufficient.

[0016] In at least one embodiment of the method provided in this disclosure, determining whether the electric braking capability of the drive motor is limited includes: Obtain the current available charging power of the power battery; Determine whether the available charging power of the battery is less than the peak power generation of the drive motor; and, If so, it is determined that the electric braking capability is limited.

[0017] The above solution has the following technical advantages: accurately identifying whether the electric braking capability is limited.

[0018] In at least one embodiment of the method provided in this disclosure, the automatic adjustment of the active discharge power of the range extender based on the current electric braking power demand of the target vehicle and the current available charging power of the power battery includes: The current electric braking power requirement of the target vehicle is determined based on the current brake pedal opening. The active discharge power of the range extender is determined by multiplying the difference between the electric braking power requirement and the current available battery charging power by a preset redundancy factor; and, Control the range extender to operate at the active discharge power; The redundancy coefficient is used to compensate for the response delay and power fluctuation of the vehicle braking system.

[0019] The above solution has the following technical effects: when in a dangerous situation of emergency braking but insufficient braking force and the electric braking capacity is limited, the active discharge power of the range extender is linearly related to the difference between the electric braking power demand and the battery's available charging power, thereby further improving vehicle braking safety.

[0020] In at least one embodiment of the method provided in this disclosure, the engine in-cylinder braking mode exit condition includes: The first exit condition includes a brake pedal opening less than a preset opening threshold and a second duration of the brake pedal opening less than the opening threshold exceeding a preset second time threshold. The second exit condition includes a vehicle deceleration greater than a preset deceleration threshold and a third duration during which the vehicle deceleration is greater than the deceleration threshold exceeds a preset third time threshold. The third exit condition includes a fourth duration that exceeds a preset fourth time threshold, whereby the available charging power of the battery recovers to a set multiple of the peak power generation of the motor and the available charging power of the battery recovers to a set multiple of the peak power generation of the motor. If the multidimensional state parameter satisfies at least one of the first exit condition, the second exit condition, and the third exit condition, it is determined that the multidimensional state parameter satisfies the engine in-cylinder braking mode exit condition.

[0021] The above solution has the following technical effects: when the electric braking capability can meet the vehicle deceleration requirements or the power battery has sufficient charging capability to absorb all or most of the regenerative electrical energy, and there is no need to use the engine to actively discharge for assistance, the engine cylinder braking mode is exited at a set time.

[0022] In at least one embodiment of the method provided in this disclosure, obtaining the current available charging power of the power battery includes: Obtain power battery state parameters related to the available charging power of the battery, wherein the power battery state parameters include at least one of temperature, aging degree parameters, and instantaneous load; and, The available charging power of the battery is determined based on the state parameters of the power battery.

[0023] The above solution has the following technical advantages: it can determine the available charging power of the battery in real time and accurately.

[0024] At least one embodiment of this disclosure also provides a vehicle braking system applied to a range-extended vehicle having a power battery, a range extender, and a drive motor, comprising: The acquisition unit is configured to acquire the current multidimensional state parameters of the target vehicle. The first-level processing unit is configured to determine, based on the multi-dimensional state parameters, whether the target vehicle is in a dangerous condition of emergency braking but insufficient braking force. The second-level processing unit is configured to determine whether the electric braking capability of the drive motor is limited when the target vehicle is in the dangerous operating condition; and, The control unit is configured to, when the electric braking capability is limited, control the range extender to activate the engine cylinder braking mode for active discharge, and automatically adjust the active discharge power of the range extender based on the current electric braking power demand of the target vehicle and the current available battery charging power of the power battery, so that the braking force meets the preset braking requirements.

[0025] 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.

[0026] 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

[0027] 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.

[0028] Figure 1 This is a schematic diagram of the powertrain composition of a range-extended vehicle in related technologies; Figure 2 A flowchart of a vehicle braking method provided for at least one embodiment of this disclosure; Figure 3 A flowchart illustrating a multi-dimensional state parameter acquisition scheme provided in at least one embodiment of this disclosure; Figure 4 A flowchart illustrating a hazardous condition identification scheme provided in at least one embodiment of this disclosure; Figure 5 Flowchart of a scheme for identifying a limitation in electric braking capability provided in at least one embodiment of this disclosure; Figure 6 A flowchart of active discharge power control logic provided for at least one embodiment of this disclosure; Figure 7 A flowchart of another vehicle braking method provided for at least one embodiment of this disclosure; Figure 8 Example flowchart of a vehicle braking method provided for at least one embodiment of this disclosure; Figure 9 A structural block diagram of a vehicle braking system provided for at least one embodiment of this disclosure; Figure 10 A structural block diagram of a program product provided for at least one embodiment of this disclosure.

[0029] Figure label: 1- Power battery; 2- Range extender; 3- Vehicle controller; 4- Brake pedal; 5- Motor controller; 6- Drive motor; 7- Gearbox; 8- Axle; 21- Engine; 22- Generator; 100- Vehicle braking system; 101- Acquisition unit; 102- First-level processing unit; 103- Second-level processing unit; 104- Control unit; 201- Processor; 202- Memory; 203- Input device; 204- Output device. Detailed Implementation

[0030] 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.

[0031] 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.

[0032] In the description of this disclosure, "multiple" means at least two, such as two or three, unless otherwise expressly and specifically limited.

[0033] 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.

[0034] 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.

[0035] The term "range-extended vehicle" in this disclosure is also referred to as a range-extended hybrid vehicle.

[0036] 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.

[0037] The term "battery management system" in this disclosure is abbreviated as BMS.

[0038] In this disclosure, the term "battery state of charge" is abbreviated as SOC, also known as the current remaining percentage of battery charge.

[0039] In the embodiments of this disclosure, the term "battery available charging power" refers to the maximum charging power allowed under the current battery SOC state, which changes dynamically with factors such as battery temperature and aging.

[0040] The term "vehicle deceleration" in this disclosure refers to the decrease in vehicle speed per unit time during operation, measured in m / s. 2 .

[0041] In this disclosure, the term "engine in-cylinder braking mode," or simply in-cylinder braking mode, refers to a braking mode in which the engine consumes power by adjusting the engine valves and fuel injection strategy. Engine in-cylinder braking mode is a commonly used operating mode of range extender engines in the target vehicle.

[0042] In this disclosure, the term "redundant design" refers to a power compensation value set in engineering practice to prevent errors in boundary condition calculations, such as setting a redundancy coefficient of 5% to 20%.

[0043] The technical approach involved in this disclosure will be briefly described below.

[0044] Figure 1 This is a schematic diagram of the powertrain composition of a range-extended vehicle in related technologies. For example... Figure 1As shown, the powertrain of a range-extended vehicle includes a power battery 1, a range extender 2, a vehicle controller 3, a brake pedal 4, a motor controller 5, a drive motor 6, a transmission 7, and an axle 8. The range extender 2 includes an engine 21 and a generator 22. The power battery 1 is electrically connected to both the range extender 2 and the motor controller 5. The range extender 2 generates electricity when the power battery 1 is low on power, either to replenish the power battery 1 or to directly power the drive motor 6. The vehicle controller 3 is signal-connected to both the brake pedal 4 and the motor controller 5, receiving driver commands and coordinating the operation of various components. The motor controller 5 controls the output torque of the drive motor 6. The drive motor 6 is connected to the axle 8 via the transmission 7, ultimately driving the range-extended vehicle.

[0045] To address the technical problems of limited vehicle braking safety, rigid control logic, and insufficient economy caused by relying on fixed SOC ranges for active discharge of the range extender, this disclosure proposes a dynamically coordinated control method for vehicle braking. This method intelligently identifies dangerous operating conditions where emergency braking is necessary but braking force is insufficient, based on the vehicle's multi-dimensional state parameters. Only under these dangerous conditions, when the electric braking capacity of the drive motor is limited (i.e., within the braking efficiency blind zone of traditional electric braking schemes), does the method actively and precisely dissipate energy through in-cylinder braking of the engine. This ensures accurate initiation of active discharge and effective consumption of feedback energy, thereby improving vehicle braking force and effectively shortening braking distance. Furthermore, this method determines the active discharge power of the range extender in real time based on the electric braking power demand and the current available charging power of the power battery. By dynamically coordinating and controlling the active discharge power, it balances vehicle braking safety and economy. This ensures that electric braking force can intervene to effectively solve the problem of limited vehicle braking safety, while avoiding frequent intervention leading to frequent charging and discharging of the power battery, effectively improving overall vehicle economy and extending the lifespan of the power battery.

[0046] Based on this, the method disclosed herein makes real-time decisions and dynamically coordinates the discharge power of the range extender based on multiple parameters such as the electric braking power demand, the available battery charging power, and the vehicle deceleration, thus balancing vehicle braking safety and economy. When the electric braking capacity is restored according to the engine in-cylinder braking mode exit condition and it is no longer necessary to meet the braking demand through engine in-cylinder braking energy consumption, the engine in-cylinder braking mode is directly exited, the active discharge of the range extender is stopped, and the normal control state of the vehicle braking system is restored, ensuring that the braking process is safe and controllable throughout, while avoiding unnecessary energy consumption and further maintaining the economic efficiency of the vehicle operation.

[0047] Based on this, the method disclosed herein achieves redundant compensation for power fluctuations by introducing a redundancy coefficient, ensuring that the electric braking force of the range-extended vehicle always meets the braking requirements. After completing the dynamic coordination of braking requirements and power redundancy compensation, when it is determined that the electric braking capability has been restored, the engine in-cylinder braking mode is directly exited, the active discharge of the range extender is stopped, and the vehicle braking system returns to the normal control state.

[0048] Based on this, the method disclosed herein achieves energy tiered management. By accurately initiating active discharge, it can prioritize the consumption of regenerative energy, avoid frequent battery charging and discharging, reduce ineffective losses of the power battery, and extend the service life of the power battery. At the same time, it can disengage in time when the electric braking capacity meets the braking requirements of the entire vehicle, without maintaining the active discharge of the range extender and the in-cylinder braking state of the engine. This ensures the stability and safety of the braking process and further improves the economic performance of the entire vehicle operation.

[0049] 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 a range-extended vehicle, i.e., the target vehicle, which has a power battery, a range extender, and a drive motor. Figure 2 As shown, the method may include the following steps S10-S40 to achieve the vehicle braking function.

[0050] Step S10: Obtain the current multidimensional state parameters of the target vehicle.

[0051] Step S20: Determine whether the target vehicle is in a dangerous condition of emergency braking but insufficient braking force based on multi-dimensional state parameters.

[0052] Step S30: When the target vehicle is in this dangerous condition, determine whether the electric braking capability of the drive motor is limited.

[0053] Step S40: When the electric braking capacity is limited, control the range extender to activate the engine cylinder braking mode to perform active discharge, and automatically adjust the active discharge power of the range extender based on the current electric braking power demand of the target vehicle and the current available battery charging power of the power battery so that the braking force meets the preset braking demand.

[0054] It should be noted that the multidimensional state parameters are real-time results. The above scheme does not limit the operation of normal braking or emergency braking with sufficient braking force. Under normal braking and emergency braking with sufficient braking force, the range extender discharge control can be executed according to the conventional control logic in the relevant technology. The above scheme focuses on targeted optimization for dangerous conditions of emergency braking with insufficient braking force and limited electric braking capability of the drive motor.

[0055] In the above scheme, this disclosure does not limit the type of multi-dimensional state parameters in step S10 or the method for obtaining them. In application scenarios, in addition to the schemes described in the following embodiments, multi-dimensional state parameters may also include any one or more combinations of vehicle speed, brake pedal opening, vehicle speed change rate, power battery SOC value, and road surface adhesion coefficient. Multi-dimensional state parameters can be directly collected through the target vehicle's existing sensors and vehicle controller communication network, without the need for additional hardware equipment, thereby reducing costs. When the system executes step S10, it can select appropriate multi-dimensional state parameters according to the actual vehicle application scenario to ensure the accuracy of the dangerous condition judgment in step S20.

[0056] In the above scheme, this disclosure does not limit the dangerous condition identification scheme in step S20. In application scenarios, in addition to the schemes described in the later embodiments, dangerous conditions of emergency braking but insufficient braking force can also be identified and judged by the vehicle's braking deceleration threshold, the difference range between the current braking torque demand and the existing available braking torque. When the system executes step S20, it can select an appropriate identification and judgment method according to the actual application scenario of the vehicle to ensure the timeliness and accuracy of dangerous condition judgment and provide a reliable judgment basis for subsequent braking force supplementation control.

[0057] In the above scheme, this disclosure does not limit the scheme for identifying the limited electric braking capability in step 30. In application scenarios, in addition to the schemes described in the following embodiments, the state of limited electric braking capability can also be identified and judged by any one or a combination of the current maximum output torque threshold of electric braking, the actual operating temperature of the motor, and the maximum allowable feedback power of the power battery. When the system executes step S30, it can combine the configuration characteristics of the vehicle power system to select an appropriate scheme for identifying the limited electric braking capability, accurately determine whether the electric braking has reached its output limit, and ensure the reliability of the identification result of the limited electric braking capability.

[0058] In the above scheme, this disclosure does not limit the active discharge power control logic in step 40. In application scenarios, in addition to the schemes described in the following embodiments, the active discharge power control can further adjust the active discharge power based on one or more of the vehicle's current power request, the range extender's operating status, and the remaining power of the power battery. When the system executes step 40, it can select appropriate active discharge power control logic according to the actual application scenario of the vehicle to ensure that the braking force meets the preset braking requirements, while also taking into account the power smoothness during vehicle driving, avoiding the impact of sudden changes in active discharge power on the overall vehicle driving comfort, and improving the safety and user experience of the target vehicle's active discharge process.

[0059] Some embodiments of this disclosure also provide systems, storage media, and program products corresponding to the methods described above.

[0060] The method provided in at least one embodiment of this disclosure is applicable to any existing vehicle application scenario where the engine needs to actively consume power during emergency braking but insufficient braking force. For example, in scenarios requiring significant braking force, such as continuous braking down a long slope or rapid deceleration at high speed, when the power battery has reached its electric braking output limit and cannot provide sufficient electric braking force, the method of this disclosure can be used to control the engine to promptly enter the in-cylinder braking mode to meet the braking requirements, reduce the load on the mechanical braking system, avoid overheating and brake fade, and ensure braking safety.

[0061] In some embodiments, Figure 2 Based on the proposed solution, to accurately identify dangerous situations requiring emergency braking but with insufficient braking force, the target vehicle includes a brake pedal. Multidimensional state parameters include brake pedal opening, vehicle deceleration, and a first duration during which the brake pedal opening is greater than a preset opening threshold and the vehicle deceleration remains less than a preset deceleration threshold. Brake pedal opening, vehicle deceleration, and the first duration are a set of relatively universal and preferred multidimensional state parameters. The opening and deceleration thresholds can be obtained through calibration and can be set individually for different vehicles and application scenarios. By combining these multiple parameters, the driver's actual braking needs can be identified more accurately, ensuring that necessary intervention is not missed while avoiding unnecessary active discharge actions that consume excess energy.

[0062] Figure 3 A flowchart illustrating a multi-dimensional state parameter acquisition scheme provided for at least one embodiment of this disclosure. Figure 2 Based on the proposed solution, in order to obtain multidimensional state parameters at low cost, such as Figure 3 As shown, step S10 may further include the following sub-steps S101-S103.

[0063] Sub-step S101: Obtain the current brake pedal signal and vehicle speed signal of the target vehicle.

[0064] Sub-step S102: Determine the brake pedal opening based on the brake pedal signal.

[0065] Sub-step S103: Determine the vehicle deceleration based on the vehicle speed signal.

[0066] Sub-step S104: When the brake pedal opening is greater than the opening threshold and the vehicle deceleration is continuously less than the deceleration threshold, obtain the first duration.

[0067] Specifically, the brake pedal opening can be directly obtained by parsing the brake pedal signal through the vehicle control unit (VCU), the vehicle deceleration can be obtained by differentiating the vehicle speed signal from the VCU, and the first duration can be obtained through a timer. The brake pedal signal and vehicle speed signal are standard vehicle signals. Sub-steps S101-S103 eliminate the need for additional sensors to collect multi-dimensional state parameters, thus avoiding additional vehicle manufacturing costs. Furthermore, this decision logic directly relies on existing vehicle signals for calculation, resulting in a simple and efficient processing flow without adding any computational burden.

[0068] Figure 4 A flowchart illustrating a hazardous condition identification scheme provided for at least one embodiment of this disclosure. Figure 2 or Figure 3 Based on the plan, in order to accurately identify dangerous situations such as emergency braking but insufficient braking force, Figure 4 As shown, step S20 may further include the following sub-steps S201-S202.

[0069] Sub-step S201: Determine whether the following conditions are met simultaneously: the brake pedal opening is greater than the opening threshold, the vehicle deceleration is continuously less than the deceleration threshold, and the first duration is greater than the preset first time threshold.

[0070] Sub-step S202: If yes, determine that the target vehicle is in a dangerous condition.

[0071] Specifically, when the driver depresses the brake pedal and the pedal opening exceeds a threshold, an emergency braking command is identified. At this point, it is determined that the vehicle's deceleration remains below a deceleration threshold and the first duration exceeds a preset first time threshold to prevent false triggering due to sudden deceleration changes. The combination of these conditions indicates that although the driver has issued an emergency braking command, the vehicle's actual deceleration is far below the standard, thus indicating insufficient braking force. By combining these conditions, the driver's true braking needs can be identified more accurately, ensuring that necessary intervention is not missed and avoiding unnecessary active discharge actions that waste excess energy.

[0072] In some embodiments, Figure 4Based on the scheme, to adapt to different working conditions, the opening threshold in step S201 is adjustable, with a recommended value of, for example, 70%; the deceleration threshold is adjustable, with a range of 3~6 m / s², and a recommended value of, for example, 3 m / s²; the first time threshold ranges from 1~2 s. Firstly, in normal road driving, the driver's pedal opening for routine deceleration and following braking is generally ≤50%. Only in emergency avoidance scenarios requiring rapid stopping will the brake pedal be pressed deeper to over 60%. Therefore, setting a 70% opening threshold can effectively distinguish the driver's core intention for routine braking from emergency braking, avoiding misjudgment in routine braking scenarios. Secondly, the vehicle deceleration range for routine braking is 0.6~1.5 m / s², and the vehicle deceleration range for emergency braking is 6~10 m / s². The national standard for passenger cars stipulates that the deceleration of passenger cars during emergency braking should be ≥4 m / s², for example, see GB / T 38186-2019. When the vehicle deceleration is continuously below 3 m / s² for more than 1~2 seconds... At time s, it can clearly distinguish the condition of emergency braking with insufficient braking force, that is, the abnormal state of "the driver has issued the maximum emergency braking demand, but the output efficiency of the braking system is severely degraded, resulting in the inability to meet the statutory safety requirements". It will not misjudge the condition of normal braking and emergency braking with sufficient braking force as the condition of emergency braking with insufficient braking force. In addition, considering the extreme scenarios such as the vehicle being fully loaded and the road surface being wet / slippery / icy and snowy with low adhesion, the road surface adhesion coefficient limit will cause the maximum available deceleration of the vehicle to decrease. The threshold of 3m / s² can effectively avoid misjudgment under low adhesion road surface. While ensuring the accuracy of judgment, it reduces the complexity of system detection and adapts to the parameter adjustment needs of different driving habits and different vehicle models. Then, when the driver performs emergency braking to avoid a hazard, they will continuously press the brake pedal for more than 1 second, without any instantaneous pressing and immediate release. Setting a duration of 1-2 seconds accurately matches the continuous operation characteristics of emergency braking, while filtering out momentary invalid operations such as accidental pedal pressing. Combined with the national standard for passenger cars GB12676-2014, which stipulates that the braking coordination time of commercial vehicle braking systems is ≤0.35s for hydraulic braking and ≤0.6s for pneumatic braking, setting a first time threshold of 1-2 seconds is much greater than the maximum coordination time of the braking system. This can effectively avoid instantaneous jumps during the braking deceleration establishment process. It can ensure that in abnormal conditions of insufficient braking force, the judgment can be completed quickly and subsequent safety warning / assistance strategies can be triggered, avoiding the risk of collision caused by excessive braking distance. Furthermore, the duration filtering logic can filter out instantaneous abnormal values ​​caused by road bumps and wheel speed signal fluctuations, greatly improving the anti-interference capability of the judgment.

[0073] Figure 5 A flowchart illustrating a limited electric braking capability identification scheme provided for at least one embodiment of this disclosure. Figures 2-4 Based on any one of the solutions, in order to accurately identify whether the electric braking capability is limited, such as Figure 5As shown, the electric braking capability limitation identification scheme in step S30 can further include the following sub-steps S301-S303.

[0074] Sub-step S301: Obtain the current available charging power of the power battery.

[0075] Sub-step S302: Determine whether the available charging power of the battery is less than the peak power generation of the drive motor.

[0076] Sub-step S303: If so, determine that the electric braking capability is limited.

[0077] It should be noted that the peak power output of the motor is a parameter on the motor nameplate and does not need to be obtained in real time.

[0078] In the above scheme, sub-step S302 aims to verify that the charging capacity of the power battery is insufficient to match the power generation capacity of the drive motor, thereby triggering the power limitation of the battery management system (BMS). Sub-steps S301-S303 can identify whether the electric braking capacity is limited based on the current actual charging capacity of the power battery. This judgment is made using only parameters of the power battery and drive motor, without the need for additional detection devices or complex algorithms. The identification logic is simple and clear, and the identification results are accurate and reliable. It can quickly determine the state of limited electric braking capacity, providing an accurate basis for subsequent adjustments to braking pressure compensation, thus improving the reliability and stability of the overall braking control scheme.

[0079] In some embodiments, Figure 5 Based on the proposed solution, to reduce implementation costs, the available battery charging power in sub-step S301 can be obtained through the battery management system. The battery management system generates and issues the available battery charging power based on the real-time detected cell status. The cell status can include at least one of the cell's current temperature, current SOC, and maximum allowable charging current. The battery management system quickly calculates the current maximum allowable battery charging power by combining these current cell parameters. This eliminates the need for additional vehicle structure modifications and allows for direct reuse of existing parameters, further reducing the requirement for additional hardware or data and lowering the implementation cost of the solution.

[0080] In some embodiments, Figure 5 Based on the scheme, in order to obtain real-time and accurate battery charging power, sub-step S301 may further include the following sub-steps S301a-S301b.

[0081] Sub-step S301a: Obtain power battery state parameters related to the available charging power of the battery, wherein the power battery state parameters include at least one of temperature, aging degree parameters and instantaneous load.

[0082] Sub-step S301b: Determine the available charging power of the battery based on the state parameters of the power battery.

[0083] It should be noted that the power battery status parameters and the battery's available charging power are real-time results.

[0084] Among them, the state parameters of the power battery affect the available charging power of the battery. By integrating the multi-dimensional state parameters of the power battery to correct the calculation results, the final available charging power of the battery can be more in line with the actual working conditions of the vehicle, further improving the accuracy of the identification results of limited electric braking capability and ensuring the precision of subsequent braking control adjustments.

[0085] In some embodiments, Figure 5 Based on the scheme, in order to enable the vehicle braking control to respond promptly to changes in vehicle status, the electric braking capability limitation identification scheme in step S30 may also include the following sub-step S304.

[0086] Sub-step S304: If not, in the next control cycle of the current control cycle, determine again whether the target vehicle is in a dangerous condition of emergency braking but insufficient braking force based on the multi-dimensional state parameters.

[0087] The cyclic judgment mechanism set in sub-step S304 can continuously monitor the status of electric braking capability, avoid missing abnormal conditions in a single judgment, ensure the continuity and real-time performance of electric braking limitation status identification, enable vehicle braking control to respond to changes in vehicle status in a timely manner, and further improve the accuracy of dangerous condition identification results and the safety of braking control.

[0088] Figure 6 A flowchart illustrating the active discharge power control logic provided for at least one embodiment of this disclosure. Figures 2-5 Based on any of the schemes, in order to further improve vehicle braking safety, the active discharge power control logic in step S40 may further include the following sub-steps S401-S403.

[0089] Sub-step S401: Determine the current electric braking power requirement of the target vehicle based on the current brake pedal opening.

[0090] Sub-step S402: Determine the active discharge power of the range extender by multiplying the difference between the electric braking power demand and the current available battery charging power by a preset redundancy coefficient.

[0091] Sub-step S403: Control the range extender to operate at active discharge power.

[0092] Specifically, sub-steps S401-S403 can accurately match the user's braking intention based on the brake pedal opening. Then, by calculating the range extender's active discharge power through the difference and redundancy coefficient, the accurate electric braking power demand is determined. This ensures that the difference between the range extender's active discharge power, the electric braking power demand, and the battery's available charging power is linear. This guarantees that the electric braking has sufficient power margin to meet the braking demand while avoiding excessive discharge power from the range extender that could affect the vehicle's energy utilization efficiency. It achieves a balance between braking safety and energy economy, ensuring that the electric braking power output meets the braking demand and quickly responds to the vehicle's braking requirements.

[0093] In some embodiments, Figure 6 Based on the proposed solution, to ensure rapid braking response in hazardous conditions, the electric braking power requirement in sub-step S401 can be obtained by looking up a table based on the brake pedal opening. Different brake pedal openings correspond to different electric braking power requirements, which can be pre-calibrated and stored in a preset table. During actual braking, the corresponding value can be directly read based on the currently acquired pedal opening, eliminating the need for complex calculations and enabling faster braking response.

[0094] In some embodiments, Figure 6 Based on the proposed solution, to ensure braking effectiveness under hazardous conditions, the electric braking power requirement in sub-step S401 can be obtained based on the brake pedal opening, vehicle speed, and gear position. Specifically, a pre-trained intent recognition model can output the corresponding result. This model uses brake pedal opening, vehicle speed, and gear as input parameters and comprehensively considers braking demands under different driving conditions, outputting an electric braking power requirement that closely matches the actual driving scenario. Compared to a single lookup table method, this approach is more adaptable to complex and changing driving conditions. Furthermore, the calculation process can be completed using the vehicle's existing controller, eliminating the need for additional hardware costs and ensuring braking response speed while improving the accuracy of the electric braking power requirement calculation.

[0095] In some embodiments, Figure 6 Based on the proposed solution, to further ensure braking performance, the active discharge power in sub-step S402 is... It can be obtained through the following formula:

[0096] In the formula, Indicates the power required for electric braking. Indicates the battery's available charging power. This represents the redundancy coefficient.

[0097] in, And redundancy coefficient This indicates a redundancy factor used to compensate for response delays and power fluctuations in the vehicle's braking system, based on the power fluctuation range during active discharge of most engines. The recommended range is 1.05 to 1.2. Redundancy factor. A fixed value can be taken, but the specific value needs to be determined based on the stability of the engine's power during active discharge; the average value of the power fluctuation can be used. When the power fluctuation is small, the redundancy coefficient... The redundancy factor can be set accordingly; if the power fluctuation is large, the redundancy factor should be adjusted accordingly. The larger value should be selected accordingly.

[0098] Figure 7 A flowchart illustrating another vehicle braking method provided for at least one embodiment of this disclosure. Figures 2-6 Based on any of the proposed solutions, to avoid unnecessary damage to the vehicle's powertrain components, such as Figure 7 As shown, the method may further include the following steps S50-S70.

[0099] Step S50: Monitor multidimensional state parameters during active discharge of the range extender.

[0100] Step S60: Determine whether the multi-dimensional state parameters meet the preset engine in-cylinder braking mode exit conditions.

[0101] Step S70: When the multi-dimensional state parameters meet the conditions for exiting the engine in-cylinder braking mode, control the range extender to exit the engine in-cylinder braking mode to end the active discharge.

[0102] In particular, steps S50-S70 enable real-time monitoring of the vehicle's operating status during the active discharge process of the range extender. When the conditions for exiting the engine cylinder braking mode are met, the engine cylinder braking mode is exited in a timely manner, avoiding the range extender from being in a continuous braking state, which may affect the vehicle's power output or cause unnecessary wear and tear on the vehicle's braking system components. This balances the safety of brake energy recovery with the reliability of system operation and adapts to the braking needs of different operating stages of the vehicle.

[0103] In some embodiments, Figure 7Based on the scheme, the engine in-cylinder braking mode exit conditions include a first exit condition, a second exit condition, and a third exit condition. The first exit condition includes a second duration where the brake pedal opening is less than a preset opening threshold and the duration of this duration exceeds a preset second time threshold. The second exit condition includes a third duration where the vehicle deceleration is greater than a preset deceleration threshold and the duration of this duration exceeds a preset third time threshold. The third exit condition includes a fourth duration where the battery's available charging power recovers to a set multiple of the motor's peak power generation and the duration of this recovery exceeds a preset fourth time threshold. If the multi-dimensional state parameters satisfy at least one of the first, second, and third exit conditions, the multi-dimensional state parameters are determined to satisfy the engine in-cylinder braking mode exit conditions. Specifically, the first exit condition is used to determine that the driver's braking force demand has decreased; the second exit condition is used to determine that the vehicle deceleration has recovered to the expected level and the insufficient braking force situation has been resolved; and the third exit condition is used to determine that the power battery has sufficient charging capacity to absorb all or most of the regenerative energy and that active engine discharge is no longer needed for assistance.

[0104] In some embodiments, the second time threshold, the third time threshold, and the fourth time threshold are equal and can be set to time. T Among these, the electric braking capacity is sufficient to meet the vehicle's deceleration requirements, or the power battery already has sufficient charging capacity to absorb all or most of the regenerative energy, eliminating the need for active engine discharge assistance, and the duration is [not specified]. T You can exit after that. T It is recommended to use a value of 3-5 seconds to avoid prolonged active discharge from affecting the vehicle's fuel economy.

[0105] In some embodiments, the recommended value range for the multiplier is 0.9 to 1. For range-extended vehicles, in the regenerative braking link that converts kinetic energy from the wheels into electrical energy from the battery, there are multiple levels of fixed efficiency losses: the drive motor's power generation efficiency is 92% to 95%, the motor controller efficiency is approximately 97% to 98%, the mechanical transmission efficiency is 90% to 93%, and the overall link efficiency is only 80% to 88%. Therefore, the actual charging power ultimately transmitted to the battery is only 0.8 to 0.88 times the peak power generation of the motor. To fully absorb the regenerative braking energy from the motor, the available charging power of the battery should be at least 0.8 times the peak power generation of the motor; this is the minimum critical value for matching design. However, to ensure the stability of the regenerative braking function and avoid abnormal braking performance due to insufficient battery charging power, the available charging power of the battery should not be less than 0.9 times the peak power generation of the motor. At the same time, economic efficiency must also be considered to prevent excessive battery drain caused by active engine discharge; therefore, the available charging power of the battery does not need to exceed the peak power generation of the motor.

[0106] Figure 8 An example flowchart of a vehicle braking method provided for at least one embodiment of this disclosure. Figure 8 As shown, the method includes the following steps: 1) Determine whether the vehicle is in an emergency braking condition but the braking force is insufficient. The determination conditions include simultaneously satisfying that the brake pedal opening is greater than the opening threshold, the vehicle deceleration is less than the deceleration threshold, and the duration is greater than the first time threshold. 2) Determine whether the electric braking capability is limited (also known as insufficient power battery capability). The determination criteria include that the available power of the battery is less than the peak power generation of the motor. If the electric braking capability is limited, proceed to 3) Calculate the active discharge power to ensure that the power battery has sufficient capability to support the electric braking output.

[0107] 3) Activate the engine cylinder braking mode to perform active discharge, and simultaneously calculate the active discharge power in real time for discharge.

[0108] 4) Exit the engine cylinder braking mode to end active discharge.

[0109] Figure 9 This 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 power battery, a range extender, and a drive motor. Figure 9 As shown, the vehicle braking system 100 integrates an acquisition unit 101, a first-level processing unit 102, a second-level processing unit 103, and a control unit 104.

[0110] The acquisition unit 101 is configured to acquire the current multidimensional state parameters of the target vehicle.

[0111] The first-level processing unit 102 is configured to determine whether the target vehicle is in a dangerous condition of emergency braking but insufficient braking force based on multi-dimensional state parameters.

[0112] The second-level processing unit 103 is configured to determine whether the electric braking capability of the drive motor is limited when the target vehicle is in the dangerous operating condition.

[0113] The control unit 104 is configured to control the range extender to activate the engine cylinder braking mode for active discharge when the electric braking capability is limited, and to automatically adjust the active discharge power of the range extender based on the current electric braking power demand of the target vehicle and the current available battery charging power of the power battery so that the braking force meets the preset braking requirements.

[0114] 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.

[0115] In some embodiments, Figure 9 Based on the scheme, the acquisition unit 101 can be implemented by corresponding sensors or receiving modules. The first-level processing unit 102, the second-level processing unit 103, and the control unit 104 can be implemented by controllers with corresponding programs.

[0116] In some embodiments, Figure 9 Based on this design, the vehicle braking system 100 also integrates a monitoring unit and a disengagement unit. The monitoring unit is configured to monitor multi-dimensional state parameters when the stroke extender is actively discharging. The disengagement unit is configured to determine whether the multi-dimensional state parameters meet the preset engine in-cylinder braking mode disengagement conditions, and when the multi-dimensional state parameters meet the engine in-cylinder braking mode disengagement conditions, control the stroke extender to disengage from the engine in-cylinder braking mode to end the active discharge.

[0117] 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.

[0118] This disclosure also provides a program product, such as... Figure 10 As shown, the program product includes one or more processors 201 and memory 202. Figure 10 Take a processor 201 as an example.

[0119] The controller may also include an input device 203 and an output device 204.

[0120] The processor 201, memory 202, input device 203, and output device 204 can be connected via a bus or other means. Figure 10Taking the example of a connection between China and Israel via a bus.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] Although embodiments of the present disclosure have been shown and described above, it is 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 power battery, a range extender, and a drive motor, characterized in that, include: Obtain the current multidimensional state parameters of the target vehicle; Based on the multidimensional state parameters, it is determined whether the target vehicle is in a dangerous operating condition of emergency braking but insufficient braking force. When the target vehicle is in the dangerous operating condition, determine whether the electric braking capability of the drive motor is limited; and, When the electric braking capability is limited, the range extender is controlled to activate the engine cylinder braking mode for active discharge. The active discharge power of the range extender is automatically adjusted based on the current electric braking power demand of the target vehicle and the current available charging power of the power battery, so that the braking force meets the preset braking requirements.

2. The method according to claim 1, characterized in that, Also includes: The multidimensional state parameters are monitored during active discharge of the range extender; Determine whether the multidimensional state parameters meet the preset engine in-cylinder braking mode exit conditions; as well as, When the multidimensional state parameters meet the engine in-cylinder braking mode exit condition, the range extender is controlled to exit the engine in-cylinder braking mode to end the active discharge.

3. The method according to claim 1 or 2, characterized in that, The target vehicle includes a brake pedal, and the multidimensional state parameters include: Brake pedal opening, Vehicle deceleration, and Simultaneously satisfying the first duration where the brake pedal opening is greater than a preset opening threshold and the vehicle deceleration is continuously less than a preset deceleration threshold.

4. The method according to claim 3, characterized in that, The determination of whether the target vehicle is in a dangerous condition of emergency braking but insufficient braking force based on the multi-dimensional state parameters includes: Determine whether the following conditions are met simultaneously: the brake pedal opening is greater than the opening threshold, the vehicle deceleration is continuously less than the deceleration threshold, and the first duration is greater than a preset first time threshold; and... If so, the target vehicle is determined to be in the dangerous operating condition.

5. The method according to claim 1 or 2, characterized in that, The determination of whether the electric braking capability of the drive motor is limited includes: Obtain the current available charging power of the power battery; Determine whether the available charging power of the battery is less than the peak power generation of the drive motor; and, If so, it is determined that the electric braking capability is limited.

6. The method according to claim 1 or 2, characterized in that, The automatic adjustment of the range extender's active discharge power based on the target vehicle's current electric braking power demand and the power battery's current available charging power includes: The current electric braking power requirement of the target vehicle is determined based on the current brake pedal opening. The active discharge power of the range extender is determined by multiplying the difference between the electric braking power requirement and the current available battery charging power by a preset redundancy factor; and, Control the range extender to operate at the active discharge power; The redundancy coefficient is used to compensate for the response delay and power fluctuation of the vehicle braking system.

7. The method according to claim 2, characterized in that, The conditions for exiting the engine in-cylinder braking mode include: The first exit condition includes a brake pedal opening less than a preset opening threshold and a second duration of the brake pedal opening less than the opening threshold exceeding a preset second time threshold. The second exit condition includes a vehicle deceleration greater than a preset deceleration threshold and a third duration during which the vehicle deceleration is greater than the deceleration threshold exceeds a preset third time threshold. The third exit condition includes a fourth duration that exceeds a preset fourth time threshold, whereby the available charging power of the battery recovers to a set multiple of the peak power generation of the motor and the available charging power of the battery recovers to a set multiple of the peak power generation of the motor. If the multidimensional state parameter satisfies at least one of the first exit condition, the second exit condition, and the third exit condition, it is determined that the multidimensional state parameter satisfies the engine in-cylinder braking mode exit condition.

8. The method according to claim 5, characterized in that, The step of obtaining the current available charging power of the power battery includes: Obtain power battery state parameters related to the available charging power of the battery, wherein the power battery state parameters include at least one of temperature, aging degree parameters, and instantaneous load; and, The available charging power of the battery is determined based on the state parameters of the power battery.

9. A vehicle braking system applied to a range-extended vehicle having a power battery, a range extender, and a drive motor, characterized in that, include: The acquisition unit is configured to acquire the current multidimensional state parameters of the target vehicle. The first-level processing unit is configured to determine, based on the multi-dimensional state parameters, whether the target vehicle is in a dangerous condition of emergency braking but insufficient braking force. The second-level processing unit is configured to determine whether the electric braking capability of the drive motor is limited when the target vehicle is in the dangerous operating condition; and, The control unit is configured to, when the electric braking capability is limited, control the range extender to activate the engine cylinder braking mode for active discharge, and automatically adjust the active discharge power of the range extender based on the current electric braking power demand of the target vehicle and the current available battery charging power of the power battery, so that the braking force meets the preset braking requirements.

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.

Images