Vehicle, brake control method and device thereof, electronic equipment, medium and product

Abstract

The invention discloses a vehicle and a braking control method and device thereof, electronic equipment, a medium and a product, and the braking control method of the vehicle comprises the steps that when a driving motor of the vehicle drives the vehicle to run based on first target efficiency, whether the battery feedback power of the vehicle is limited or not is judged in response to a deceleration instruction; under the condition that the battery feedback power is limited, the driving motor is controlled to conduct brake feedback based on second target efficiency; wherein the first target efficiency is greater than the second target efficiency. According to the brake control method of the vehicle, when the battery feedback power is limited, the power fed back to the battery is reduced by reducing the efficiency of the driving motor, the battery of the vehicle can be prevented from being overcharged, meanwhile, caliper brake intervention is not needed, and the service life of a vehicle brake disc is prolonged.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a vehicle and its braking control method, device, electronic equipment, medium, and product. Background Technology

[0002] In related technologies, calipers are typically used to supplement braking when battery regenerative power is limited. While this technology can dissipate some of the regenerative power to a certain extent, caliper braking can cause the brake discs to overheat, which in turn affects their lifespan. Furthermore, since braking regenerative power is still present, it may also lead to overcharging of the vehicle's battery. Summary of the Invention

[0003] This application aims to at least partially address one of the technical problems in the related art. Therefore, the purpose of this application is to provide a vehicle and its braking control method, device, electronic equipment, medium, or product to prevent overcharging of the vehicle's battery and extend the lifespan of the vehicle's brake discs.

[0004] In a first aspect, embodiments of this application provide a braking control method for a vehicle, the method comprising: when the vehicle's drive motor drives the vehicle to travel based on a first target efficiency, in response to a deceleration command, determining whether the vehicle's battery regenerative power is limited; if the battery regenerative power is limited, controlling the drive motor to perform braking regenerative based on a second target efficiency; wherein the first target efficiency is greater than the second target efficiency.

[0005] For example, determining whether the battery regenerative power of the vehicle is limited includes: obtaining the allowed battery regenerative power of the vehicle; and determining that the battery regenerative power is limited if the allowed battery regenerative power is less than or equal to a first target power threshold.

[0006] For example, the method further includes: controlling the vehicle to perform caliper braking when the battery's allowable feedback power is less than or equal to a second target power threshold; wherein the second target power threshold is less than the first target power threshold.

[0007] For example, controlling the vehicle to perform caliper braking includes: controlling the vehicle to perform caliper braking based on the difference between the second target power threshold and the battery's allowable regenerative power.

[0008] For example, the method further includes: charging the vehicle's battery based on a target charging power when the battery's allowable feedback power is less than or equal to a first target power threshold and greater than a second target power threshold, wherein the target charging power is calculated based on the second target efficiency.

[0009] For example, the method further includes: charging the battery based on the battery's allowable feedback power when the battery's allowable feedback power is less than or equal to a second target power threshold, wherein the second target power threshold is less than the first target power threshold.

[0010] For example, the method further includes: determining a first target power consumption; and controlling the vehicle's thermal management system to cool down based on the first target power consumption.

[0011] For example, determining the first target power consumption includes: determining the first target power consumption based on the current operating condition of the vehicle, wherein the current operating condition includes at least one of the current brake pedal opening, the current ambient temperature, and the current coolant temperature of the thermal management system.

[0012] For example, the method further includes: determining a second target power consumption when the battery feedback power is limited; and controlling the vehicle's generator to perform anti-drag braking on the vehicle's engine based on the second target power consumption.

[0013] For example, when the drive motor drives the vehicle based on the first target efficiency, the generator operates based on the third target efficiency; determining the second target power consumption includes: determining the second target power consumption based on the generator's rotational speed and torque, and the fourth target efficiency; wherein the third target efficiency is greater than the fourth target efficiency.

[0014] For example, the third target efficiency is obtained by looking up a third efficiency MAP, which is obtained by calibrating the generator's operating efficiency based on the maximum torque-current ratio; the fourth target efficiency is obtained by looking up a fourth efficiency MAP, which is obtained by calibrating the generator's operating efficiency based on the minimum torque-current ratio.

[0015] For example, the first target efficiency is obtained by looking up a first efficiency MAP, which is obtained by calibrating the operating efficiency of the drive motor based on the maximum torque-current ratio; the second target efficiency is obtained by looking up a second efficiency MAP, which is obtained by calibrating the operating efficiency of the drive motor based on the minimum torque-current ratio.

[0016] Secondly, embodiments of this application provide a vehicle braking control device, the device comprising: a judgment module, configured to, in response to a deceleration command, determine whether the battery regenerative power of the vehicle is limited when the vehicle's drive motor drives the vehicle based on a first target efficiency; and a control module, configured to, when the battery regenerative power is limited, control the drive motor to perform braking regenerative based on a second target efficiency; wherein the first target efficiency is greater than the second target efficiency.

[0017] Thirdly, embodiments of this application provide a vehicle including a processor, a memory, and a computer program stored in the memory and capable of running on the processor, wherein the computer program, when executed by the processor, implements the steps of the method described in the first aspect above.

[0018] Fourthly, embodiments of this application provide an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the method described in the first aspect above.

[0019] Fifthly, embodiments of this application provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in the first aspect above.

[0020] In a sixth aspect, embodiments of this application provide a computer program product that stores instructions which, when executed by a computer, implement the steps of the method described in the first aspect above.

[0021] The vehicle and its braking control method, device, electronic equipment, medium, and product according to the embodiments of this application, when the vehicle's drive motor drives the vehicle based on a first target efficiency, if there is a deceleration command and the battery feedback power is limited, the drive motor is controlled to perform braking feedback based on a smaller second target efficiency, which can reduce the power flowing back to the battery, thereby preventing the vehicle's battery from overcharging, and at the same time, caliper braking intervention is not required, thus improving the life of the vehicle's brake discs. Attached Figure Description

[0022] Figure 1 This is a flowchart of a vehicle braking control method according to the first embodiment of this application;

[0023] Figure 2 This is a schematic diagram of a vehicle architecture according to an embodiment of this application;

[0024] Figure 3(a) is a schematic diagram of a first efficiency MAP diagram according to an embodiment of this application;

[0025] Figure 3(b) is a schematic diagram of a second efficiency MAP diagram according to an embodiment of this application;

[0026] Figure 4 This is a flowchart of a vehicle braking control method according to the second embodiment of this application;

[0027] Figure 5 This is a flowchart of a vehicle braking control method according to the third embodiment of this application;

[0028] Figure 6 This is a flowchart of a vehicle braking control method according to a specific embodiment of this application;

[0029] Figure 7 This is a structural block diagram of a vehicle braking control device according to an embodiment of this application;

[0030] Figure 8 This is a schematic diagram of the structure of an electronic device according to a specific embodiment of this application. Detailed Implementation

[0031] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0032] Figure 1 This is a flowchart of a vehicle braking control method according to the first embodiment of this application. The vehicle braking control method can be executed by at least one of the vehicle control unit (VCU), domain controller, and motor control unit (MCU), such as by the vehicle control unit and the motor control unit jointly. The specific execution method can be determined according to the vehicle architecture and is not limited here.

[0033] like Figure 1 As shown, the vehicle's braking control methods include:

[0034] S11, when the vehicle's drive motor drives the vehicle based on the first target efficiency, in response to the deceleration command, it is determined whether the vehicle's battery regenerative power is limited.

[0035] In the embodiments of this application, the drive motor is a motor that drives the wheels of the vehicle to rotate. Taking a four-wheel drive vehicle as an example, such as... Figure 2As shown, this four-wheel drive vehicle includes four drive motors: FR_MOT (right front drive motor), FL_MOT (left front drive motor), RR_MOT (right rear drive motor), and RR_MOT (left rear drive motor), corresponding to the four wheels of the vehicle. Furthermore, FR_MOT and FL_MOT are controlled by a two-in-one electronic control MCU2, while RR_MOT and RL_MOT are controlled by a two-in-one electronic control MCU3.

[0036] For example, the first target efficiency is obtained by looking up a first efficiency MAP. The first efficiency MAP can be pre-calibrated, such as the first efficiency MAP obtained by calibrating the drive motor based on the maximum torque per ampere (MaxTPA), as shown in Figure 3(a). The X-axis is the motor speed, and the Y-axis is the motor torque. The first efficiency MAP is a contour map on the speed-torque plane calibrated based on MaxTPA. MaxTPA refers to obtaining the maximum torque output with the minimum stator current. The MaxTPA calibration principle can also be referred to as the high-efficiency calibration principle in this application. The first efficiency MAP can be used to calibrate the current operating point of the drive motor and find the target operating point with the highest efficiency of the drive motor. Then, control parameters that can change the drive motor from the current operating point to the target operating point are obtained. The drive motor of the above-mentioned vehicle drives the vehicle based on the first target efficiency, which means that the drive motor is controlled to drive the vehicle using these control parameters. This control method can achieve the purpose of reducing power consumption.

[0037] Specifically, the current driver-demanded torque can be obtained based on the vehicle's current throttle opening, current vehicle speed, and a predefined baseline for analyzing the driver's required torque. Based on the driver-demanded torque and the highest efficiency (i.e., the first target efficiency) in the first efficiency MAP, the target speed at the target operating point can be obtained by searching the first efficiency MAP. The current speed of the drive motor can be obtained from the current vehicle speed, and the current execution torque of the drive motor can be acquired to obtain the current operating point (current execution torque, current speed). Then, based on the current operating point (current execution torque, current speed) and the target operating point (driver-demanded torque, target speed), the control parameters that cause the drive motor to change from the current operating point to the target operating point can be obtained.

[0038] When the control parameters are obtained, torque smoothing can be performed to ensure smooth changes in the torque executed by the vehicle, reducing or avoiding vibrations during vehicle operation. For example, the torque transformation step size can be obtained based on the current executed torque, current speed, driver-demanded torque, and target speed. The calculation formula can be: |current executed torque - driver-demanded torque| / |current speed - target speed|. Then, the drive motor is controlled to change from the current executed torque to the driver-demanded torque based on the torque transformation step size.

[0039] In some examples, the deceleration command may be a braking command generated during normal braking. When the vehicle's drive motor is driving the vehicle based on a first target efficiency, the brake pedal opening can be acquired, and a deceleration command can be triggered based on the brake pedal opening. As one implementation, a deceleration command can be triggered when the brake pedal opening is less than a target opening threshold, and the rate of change of the brake pedal opening is less than a target rate of change threshold. As another implementation, the required braking torque can be obtained based on the brake pedal opening, and a deceleration command can be triggered when the required braking torque is less than a target torque threshold.

[0040] In other examples, the deceleration command can be triggered based on the accelerator pedal opening. For example, when the vehicle's drive motor is driving the vehicle based on a first target efficiency, if the accelerator pedal opening is detected to become zero (i.e., the accelerator pedal is fully released), then a deceleration command is determined to be triggered.

[0041] In other examples, the deceleration command can also be a command input by the driver through gestures, voice input, or buttons. For example, if the driver issues a voice command such as "slow down" or "slow down, slow down", it can be determined that the deceleration command is triggered.

[0042] It should be noted that when the vehicle's drive motor drives the vehicle based on the first target efficiency, if no deceleration command is detected, the vehicle braking control method of this application will not be executed.

[0043] In the embodiments of this application, limited battery feedback power can refer to limited battery charging, which may include charging limitations caused by factors such as the working efficiency of the drive motor, as well as charging limitations caused by parameters such as the battery's temperature, capacity, and whether it is fully charged.

[0044] In some examples, determining whether the vehicle's battery regenerative power is limited includes: obtaining the vehicle's allowed battery regenerative power; and determining that the battery regenerative power is limited if the allowed battery regenerative power is less than or equal to a first target power threshold.

[0045] Specifically, the allowable regenerative power of a battery refers to the maximum power value at which a vehicle's battery (mainly the power battery) can safely and effectively receive and store excess energy released during vehicle braking without negatively impacting battery performance. This maximum power value is determined by the battery management system (BMS) through real-time monitoring of battery parameters. This method improves the real-time performance and accuracy of obtaining the allowable regenerative power. The first target power threshold can be determined empirically or calibrated based on the actual vehicle conditions. It can be defined as the regenerative power generated by the braking force corresponding to a fixed braking force at a fixed vehicle speed (e.g., 60 km / h, calibrable) and a fixed brake pedal opening (e.g., 30% brake pedal opening, calibrable). For example, taking a four-wheel drive vehicle as an example, and assuming all four drive motors are identical, the first target power threshold can be 4*T*n / 9550*η, where T is the real-time torque of the drive motor at 30% brake pedal opening, n is the real-time speed of the drive motor at a vehicle speed of 60 km / h, and η is the efficiency obtained by looking up the first efficiency MAP based on (T, n). It should be understood that the first target power threshold will differ depending on the vehicle architecture. For example, the number of drive motors can be one, two, three, etc., and the first target power threshold will differ for different drive motor architectures.

[0046] Optionally, the first target power threshold can be modified as needed. For example, the first target power threshold can be reduced in steps as the service life of the drive motor decreases, or it can be manually modified after vehicle modification.

[0047] S12, when the battery regenerative power is limited, controls the drive motor to perform braking regenerative based on the second target efficiency.

[0048] Among them, the efficiency of the first objective is greater than the efficiency of the second objective.

[0049] In the embodiments of this application, the second target efficiency is obtained by looking up a second efficiency MAP. The second efficiency MAP can be pre-calibrated, such as the second efficiency MAP obtained by calibrating the drive motor based on the minimum torque per ampere (MinTPA), as shown in Figure 3(b). The X-axis represents the motor speed, and the Y-axis represents the motor torque. The second efficiency MAP is a contour map on the speed-torque plane calibrated based on MinTPA. MinTPA refers to obtaining the minimum torque output with the maximum stator current. The MinTPA calibration principle can also be referred to as the inefficiency calibration principle in this application. Similar to the first efficiency MAP, the second efficiency MAP can also be used to calibrate the current operating point of the drive motor and find the target operating point with the highest efficiency of the drive motor. Then, control parameters that allow the drive motor to change from the current operating point to the target operating point are obtained. It should be noted that during the process of controlling the drive motor to switch from operating based on the first target efficiency to operating based on the second target efficiency, it is necessary to ensure that the wheel end torque does not change abruptly to reduce or avoid vibration during vehicle operation.

[0050] Specifically, taking a single-drive motor architecture as an example, under a certain operating condition, the drive motor's speed is n1, its execution torque is T1, and the battery's allowable regenerative power is P_bms_allw. Based on the high-efficiency calibration principle, the allowable output torque of the drive motor is T1_allw = (P_bms_allw*9550) / (η1*n1), where η1 is the efficiency obtained by searching the first efficiency MAP diagram shown in Figure 3(a) based on (T1, n1). Based on the low-efficiency calibration principle, the allowable output torque of the drive motor is T2_allw = (P_bms_allw*9550) / (η2*n1), where η2 is the efficiency obtained by searching the second efficiency MAP diagram shown in Figure 3(b) based on (T1, n1). Since η1 > η2, the drive motor operating based on the second target efficiency allows the vehicle to perform braking regenerative braking with greater torque, and to a certain extent, the drive motor can bear more of the vehicle's kinetic energy. Therefore, when the battery regenerative power is limited, by controlling the drive motor to perform braking regenerative based on the second target efficiency, the working point of the drive motor can be made as inefficient as possible. More of the regenerative energy is carried away by the cooling system as heat generated by the drive motor, and the power flowing back to the battery is reduced. This can prevent the battery from being overcharged and protect the battery. At the same time, caliper braking intervention is not required, which improves the life of the brake disc.

[0051] It should be noted that when the battery regenerative power is not limited, the control drive motor performs braking regenerative based on the first target efficiency, which will not lead to battery overcharging. Figures 3(a) and 3(b) show the highest efficiency regions of the first efficiency MAP and the second efficiency MAP, respectively, which are the efficiency regions corresponding to medium speed and medium torque; the curve in the upper right is the maximum torque curve, and the inflection point of the maximum torque corresponds to the peak power of the drive motor.

[0052] In some embodiments of this application, such as Figure 4 As shown, the vehicle's braking control method also includes:

[0053] S13, when the battery's allowable feedback power is less than or equal to the second target power threshold, controls the vehicle to apply caliper braking.

[0054] The second target power threshold is lower than the first target power threshold. The second target power threshold can be a variable, determined based on current operating conditions, the second target efficiency, the number of drive motors, etc. It should be understood that the second target power threshold will differ depending on the vehicle architecture; for example, the number of drive motors can be one, two, three, etc., and different numbers of drive motors correspond to different second target power thresholds.

[0055] Specifically, if the battery's allowable feedback power is less than or equal to the second target power threshold, it means that even if inefficient feedback is performed (i.e., the drive motor is controlled to perform braking feedback based on the second target efficiency), the deceleration requirement cannot be met. At this time, it is necessary to request caliper braking (which can be driven by hydraulics, small motors, etc.) to intervene and dissipate the excess power through friction, i.e., control the vehicle to perform caliper braking.

[0056] In some examples, controlling the vehicle to perform caliper braking includes: controlling the vehicle to perform caliper braking based on the difference between a second target power threshold and the battery's allowable regenerative power.

[0057] Specifically, the difference between the second target power threshold and the battery's allowable regenerative power can be calculated first. Then, the caliper braking is requested to dissipate the power difference through friction. The remaining power is then used to control the drive motor for braking regenerative braking based on the second target efficiency. Compared to caliper braking alone, this method achieves energy regeneration, prevents battery overcharging, and reduces the risk of brake disc overheating. Compared to electric braking entirely by the drive motor, this method prevents battery overcharging and improves battery safety.

[0058] In some embodiments of this application, such as Figure 5 As shown, the vehicle's braking control method also includes:

[0059] S14, if the battery's allowable feedback power is less than or equal to the first target power threshold and greater than the second target power threshold, the vehicle's battery is charged based on the target charging power.

[0060] The target charging power is calculated based on the second target efficiency, which can be the real-time feedback input power calculated based on the second target efficiency.

[0061] S15, if the battery's allowable feedback power is less than or equal to the second target power threshold, charge the battery based on the battery's allowable feedback power.

[0062] Specifically, when the battery's allowable regenerative power is less than or equal to the first target power threshold and greater than the second target power threshold, it indicates that battery charging is not severely restricted. In this case, while controlling the drive motor to perform braking regenerative braking based on the second target efficiency, the vehicle's battery is charged based on the target charging power. This can improve energy regenerative efficiency while preventing battery overcharging. When the battery's allowable regenerative power is less than or equal to the second target power threshold, it indicates that battery charging is severely restricted. In this case, charging the battery based on the battery's allowable regenerative power can prevent battery overcharging.

[0063] It should be noted that, when the battery's regenerative power is not limited, the battery can be charged based on its allowable regenerative power.

[0064] To facilitate understanding, the following will be combined with Figure 6 The braking control method for a vehicle according to this application is described through a specific implementation:

[0065] like Figure 6 As shown, at the start of control, the drive motor operates based on MAP1 by default, and the first target efficiency can be found based on MAP1. It then determines whether the vehicle needs to decelerate (e.g., by detecting easing off the accelerator or applying the brakes). If a deceleration requirement is detected, it continues to determine whether the battery regenerative power is limited; otherwise, it exits the current determination.

[0066] If the battery's allowable feedback power P_bms_allw ≤ the first target power threshold P1_lmt, then it is determined that the battery's feedback power is limited and the motor efficiency MAP2 needs to be enabled. The second target efficiency can be found based on MAP2. Otherwise, it is considered that the battery's allowable feedback power is sufficient, and the current judgment is exited.

[0067] If the battery regenerative power is limited, check if P_bms_allw ≤ the second target power threshold P2_lmt. If it does, it means that even if inefficient regenerative braking is performed (i.e., motor efficiency MAP2 is enabled), the deceleration requirement cannot be met. In this case, caliper braking can be requested to dissipate the power of (P2_lmt-P_bms_allw) through friction. Otherwise, energy regenerative braking is performed directly according to P2_lmt.

[0068] In some embodiments of this application, the vehicle braking control method further includes: determining a first target power consumption; and controlling the vehicle's thermal management system to cool down based on the first target power consumption.

[0069] Specifically, the first target power consumption can be a fixed value (determined based on experience or experimentation) or a variable. When it is a variable, the first target power consumption can be determined based on the vehicle's current operating conditions, which include brake pedal opening, ambient temperature, and the coolant temperature of the thermal management system. For example, the higher the coolant temperature of the thermal management system, the greater the first target power consumption; the greater the brake pedal opening, the greater the first target power consumption; the higher the ambient temperature, the greater the first target power consumption, and so on. For instance, the first target power consumption can be the maximum power that meets certain noise, vibration, and harshness (NVH) performance requirements under the current operating conditions. By cooling the thermal management system, the battery feedback power can be reduced, thereby reducing the risk of battery overcharging and protecting the battery. Simultaneously, it can also reduce the use of caliper braking, lowering the risk of brake disc overheating.

[0070] For example, in response to a deceleration command, or when battery power feedback is limited, the above-described steps of controlling the vehicle's thermal management system to cool down can be performed to reduce or avoid unnecessary cooling operations and achieve energy saving.

[0071] In some embodiments of this application, the vehicle braking control method further includes: determining a second target power consumption when the battery feedback power is limited; and controlling the vehicle's generator to perform reverse drag braking on the vehicle's engine based on the second target power consumption.

[0072] Specifically, the vehicle adopts a hybrid architecture, meaning it is equipped with a generator, which can be an integrated intelligent starter generator (ISG). See [link to relevant documentation]. Figure 2The ISG is mechanically connected to the engine (ENG) and can drive the engine to rotate. The second target power consumption can be a constant (determined based on experience or experimentation) or a variable. When it is a variable, the second target power consumption can be determined based on the generator's speed and torque, as well as the fourth target efficiency. Specifically, when the drive motor drives the vehicle based on the first target efficiency, the generator operates based on the third target efficiency, and the third target efficiency is greater than the fourth target efficiency. By using the generator to reverse-drive the engine in a less efficient manner (i.e., the generator can perform reverse-drive work with greater torque, and to a certain extent, more vehicle kinetic energy can be taken over by the generator), more regenerative energy can be dissipated, reducing the battery regenerative power, thereby reducing the risk of battery overcharging and protecting the battery. At the same time, it can also reduce the use of caliper braking and reduce the risk of brake disc overheating.

[0073] It should be understood that if the vehicle is a pure electric vehicle, that is, without a generator, the power consumption of the second target is zero.

[0074] For example, the third target efficiency is obtained by looking up the third efficiency MAP, and the fourth target efficiency is obtained by looking up the fourth efficiency MAP. Similar to the efficiency calibration of the drive motor, the third efficiency MAP is obtained based on the generator's operating efficiency calibrated at the maximum torque-to-current ratio, and the fourth efficiency MAP is obtained based on the generator's operating efficiency calibrated at the minimum torque-to-current ratio.

[0075] For ease of understanding, the following will be used as an example. Figure 2 Taking a four-wheel drive vehicle equipped with a generator as an example, the effect of the braking control method of this application vehicle is explained:

[0076] Under regenerative braking conditions, let the speed of the drive motor be n, the regenerative input power of the drive motor be P_fdbk_in, and the allowable regenerative power of the battery be P_bms_allw. Then, the battery charging (regenerative) power P_bms and the vehicle regenerative torque T are... 整 As shown in equations (1) and (2) respectively:

[0077] P_bms=4*P_fdbk_in*η-P1_tar-P2_tar (1)

[0078] T 整 =4*T=(P_bms_allw+P1_tar+P2_tar)*9550 / (η*n) (2)

[0079] It is evident that when P_fdbk_in is constant, by minimizing the efficiency η of the drive motor and increasing the power consumption P1_tar of the generator reverse drag and the power consumption P2_tar of the thermal management, the battery can receive less feedback power to protect it. When P_bms_allw is constant, by minimizing η and increasing P1_tar and P2_tar, each drive motor can obtain a larger braking torque T to better meet braking requirements. At the same time, the use of caliper brakes can be reduced, thus lowering the risk of brake disc overheating.

[0080] At a certain vehicle speed, the rotational speed of each drive motor is n1. If the accelerator is released / the brake is applied, the vehicle enters the regenerative braking mode. Assume that in this regenerative braking mode, the regenerative torque T1 of each drive motor is constant, and the battery allows a constant regenerative power P_mot_allw for a single drive motor. Based on (n1, T1), the first efficiency MAP shown in Figure 3(a) is used to obtain the corresponding drive motor efficiency η1; based on (n1, T1), the second efficiency MAP shown in Figure 3(b) is used to obtain the corresponding drive motor efficiency η2; the actual regenerative power of a single drive motor is P_fdbk_in = T1*n1 / 9550, where η1 > η2.

[0081] If the drive motor operates based on the first target efficiency, the feedback input power of a single drive motor is P_fdbk_out1 = P_fdbk_in * η1, and the allowable output torque of a single drive motor is T1_allw = (P_mot_allw * 9550) / (η1 * n1); if the drive motor operates based on the second target efficiency, the feedback input power of a single drive motor is P_fdbk_out2 = P_fdbk_in * η2, and the allowable output torque of a single drive motor is T2_allw = (P_mot_allw * 9550) / (η2 * n1).

[0082] a. Since η1>η2, P_fdbk_out1-P_fdbk_out2=△P>0, T2_allw-T1_allw=△T>0. In other words, in the low-efficiency mode, the drive motor can carry away more of the feedback energy as heat through the thermal management system, resulting in less power flowing back to the battery, which can better protect the battery. It also allows the vehicle to provide feedback with greater torque. To a certain extent, the drive motor can bear more of the vehicle's kinetic energy.

[0083] Therefore, compared to the first target efficiency, when the drive motor performs braking feedback based on the second target efficiency, the power flowing back to the battery is smaller, which better protects the battery. In addition, the drive motor can handle more of the vehicle's kinetic energy, better meeting the braking demand. At the same time, with the help of the thermal management system for cooling and the generator to reverse-drive the engine, the use of caliper brakes can be reduced, increasing the life of the brake discs.

[0084] In summary, the vehicle braking control method of this application embodiment, when the battery regenerative power is limited, at least controls the drive motor to operate in an inefficient mode, and can be supplemented by a thermal management system for heat dissipation and generator reverse-draft engine operation. When the battery regenerative power is severely limited, caliper braking is added. The entire process does not require additional hardware costs, thus mitigating the risk of battery overcharging, extending brake disc life, and improving braking safety. Furthermore, the solution of this application has a wide range of applications and can be applied to various different vehicle architectures, including single / dual / triple / quadruple drive motor pure electric and hybrid architectures.

[0085] Corresponding to the vehicle braking control method in the above embodiments, this application also proposes a vehicle braking control device.

[0086] Figure 7 This is a structural block diagram of a vehicle braking control device according to an embodiment of this application.

[0087] like Figure 7 As shown, the vehicle braking control device 700 includes a judgment module 710 and a control module 720. The judgment module 710 is used to determine whether the vehicle's battery regenerative power is limited in response to a deceleration command when the vehicle's drive motor is driving the vehicle based on a first target efficiency. The control module 720 is used to control the drive motor to perform braking regenerative based on a second target efficiency when the battery regenerative power is limited.

[0088] Among them, the efficiency of the first objective is greater than the efficiency of the second objective.

[0089] In some embodiments of this application, determining whether the battery regenerative power of a vehicle is limited includes: obtaining the allowable battery regenerative power of the vehicle; and determining that the battery regenerative power is limited if the allowable battery regenerative power is less than or equal to a first target power threshold; wherein the first target power threshold is related to a first target efficiency and the number of drive motors.

[0090] In some embodiments of this application, the control module 720 is further configured to: control the vehicle to perform caliper braking when the battery's allowable feedback power is less than or equal to a second target power threshold; wherein the second target power threshold is less than a first target power threshold and is related to the second target efficiency and the number of drive motors.

[0091] In some embodiments of this application, the control module 720 is further configured to: charge the vehicle's battery based on a target charging power when the battery's allowable feedback power is less than or equal to a first target power threshold and greater than a second target power threshold, wherein the target charging power is calculated based on a second target efficiency.

[0092] In some embodiments of this application, when the battery's allowable feedback power is less than or equal to a second target power threshold, the battery is charged based on the battery's allowable feedback power, where the second target power threshold is less than a first target power threshold.

[0093] In some embodiments of this application, controlling the vehicle to perform caliper braking includes: controlling the vehicle to perform caliper braking based on the difference between a second target power threshold and the battery's allowable regenerative power.

[0094] In some embodiments of this application, the control module 720 is further configured to: determine a first target power consumption; control the vehicle's thermal management system to cool down according to the first target power consumption; wherein a second target power threshold is also related to the first target power consumption.

[0095] In some embodiments of this application, determining the first target power consumption includes: determining the first target power consumption based on the current operating conditions of the vehicle.

[0096] In some embodiments of this application, the control module 720 is further configured to: determine a second target power consumption when the battery feedback power is limited; control the vehicle's generator to perform anti-drag braking on the vehicle's engine according to the second target power consumption; wherein the second target power threshold is also related to the second target power consumption.

[0097] In some embodiments of this application, when the drive motor drives the vehicle based on a first target efficiency, the generator operates based on a third target efficiency; determining the second target power consumption includes: determining the second target power consumption based on the generator's rotational speed and torque, and a fourth target efficiency; wherein the third target efficiency is greater than the fourth target efficiency.

[0098] In some embodiments of this application, the first target efficiency is obtained by looking up a first efficiency MAP, which is obtained based on the operating efficiency of the drive motor calibrated at the maximum torque-current ratio; the second target efficiency is obtained by looking up a second efficiency MAP, which is obtained based on the operating efficiency of the drive motor calibrated at the minimum torque-current ratio.

[0099] In some embodiments of this application, the third target efficiency is obtained by looking up a third efficiency MAP, which is obtained based on the operating efficiency of the generator calibrated at the maximum torque-current ratio; the fourth target efficiency is obtained by looking up a fourth efficiency MAP, which is obtained based on the operating efficiency of the generator calibrated at the minimum torque-current ratio.

[0100] It should be noted that for other specific embodiments of the vehicle braking control device 700 in this application, please refer to the specific embodiments of the vehicle braking control method described above.

[0101] This application also proposes a vehicle, which includes a processor, a memory, and a computer program stored in the memory and capable of running on the processor. When the computer program is executed by the processor, it implements the steps of the braking control method of the vehicle described in the above embodiments.

[0102] This application also proposes a computer-readable storage medium.

[0103] In this embodiment, a computer program is stored on a computer-readable storage medium, and when the computer program is executed by a processor, it implements the steps of the above-described vehicle braking control method.

[0104] This application also proposes a computer program product that stores instructions that, when executed by a computer, implement the steps of the vehicle braking control method of the above embodiments.

[0105] This application provides an electronic device, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-described vehicle braking control method.

[0106] like Figure 8 As shown, for ease of understanding, embodiments of this application illustrate a specific electronic device.

[0107] Electronic devices are intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic devices can also represent various forms of mobile devices, such as personal digital assistants, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present disclosure described and / or claimed herein.

[0108] like Figure 8As shown, the electronic device includes a computing unit 801, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 802 or a computer program loaded from a storage unit 808 into a random access memory (RAM) 803. The RAM 803 may also store various programs and data required for the operation of the electronic device. The computing unit 801, ROM 802, and RAM 803 are interconnected via a bus 804. An input / output (I / O) interface 805 is also connected to the bus 804.

[0109] Multiple components in the electronic device are connected to the I / O interface 805. These components include: an input unit 806, such as a keyboard or mouse; an output unit 807, such as various types of displays or speakers; a storage unit 808, such as a disk or optical disk; and a communication unit 809, such as a network interface card (NIC), a modem, or a wireless transceiver. The communication unit 809 allows the electronic device to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0110] The computing unit 801 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 801 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 801 executes the vehicle braking control method described above. For example, in some embodiments, the vehicle braking control method can be implemented as a computer software program tangibly contained in a machine-readable medium, such as storage unit 808. In some embodiments, part or all of the computer program can be loaded and / or installed on an electronic device via ROM 802 and / or communication unit 809. When the computer program is loaded into RAM 803 and executed by the computing unit 801, the vehicle braking control method described above can be executed. Alternatively, in other embodiments, the computing unit 801 can be configured to execute the vehicle braking control method by any other suitable means (e.g., by means of firmware).

[0111] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequential list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this application, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). In addition, computer-readable media can even be paper or other suitable media on which programs can be printed, because programs can be obtained electronically, for example, by optically scanning paper or other media, followed by editing, interpreting or otherwise processing as necessary, and then stored in computer memory.

[0112] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0113] In the description of this application, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this application, 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.

[0114] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0115] Furthermore, the terms "first," "second," etc., used in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying relative importance, or implicitly specifying the number of technical features indicated in this embodiment. Therefore, features defined with terms such as "first" and "second" in the embodiments of this application can explicitly or implicitly indicate that the embodiment includes at least one of those features. In the description of this application, the word "multiple" means at least two or more, such as two, three, four, etc., unless otherwise explicitly and specifically defined in the embodiments.

[0116] In this application, unless otherwise explicitly specified or limited in the embodiments, the terms "installation," "connection," "joining," and "fixing" appearing in the embodiments should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral part; it can also be a mechanical connection, an electrical connection, etc. Of course, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication between two components, or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific implementation.

[0117] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0118] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A brake control method of a vehicle, characterized by, The method comprises: When the drive motor of the vehicle drives the vehicle to travel based on a first target efficiency, in response to a deceleration instruction, it is determined whether the battery feedback power of the vehicle is limited; In the case that the battery feedback power is limited, the drive motor is controlled to brake feedback based on a second target efficiency; Wherein, the first target efficiency is greater than the second target efficiency.

2. The brake control method of a vehicle according to claim 1, characterized by, The determination of whether the battery feedback power of the vehicle is limited comprises: Obtain the battery allowed feedback power of the vehicle; In the case that the battery allowed feedback power is less than or equal to a first target power threshold, it is determined that the battery feedback power is limited.

3. The brake control method of a vehicle according to claim 2, characterized by The method further comprises: In the case that the battery allowed feedback power is less than or equal to a second target power threshold, the vehicle is controlled to perform caliper braking; Wherein, the second target power threshold is less than the first target power threshold.

4. The brake control method of a vehicle according to claim 3, characterized by The control of the vehicle to perform caliper braking comprises: According to the difference between the second target power threshold and the battery allowed feedback power, the vehicle is controlled to perform caliper braking.

5. The brake control method of a vehicle according to claim 2, characterized by The method further comprises: In the case that the battery allowed feedback power is less than or equal to a first target power threshold and greater than a second target power threshold, the battery of the vehicle is charged based on a target charging power, wherein the target charging power is calculated based on the second target efficiency.

6. The brake control method of a vehicle according to claim 2, characterized by The method further comprises: In the case that the battery allowed feedback power is less than or equal to a second target power threshold, the battery is charged based on the battery allowed feedback power, wherein the second target power threshold is less than the first target power threshold.

7. The brake control method of a vehicle according to claim 1, characterized by The method further comprises: Determine a first target consumption power; According to the first target consumption power, control the thermal management system of the vehicle to cool down.

8. The brake control method of a vehicle according to claim 7, characterized by The determination of the first target consumption power comprises: According to the current working condition of the vehicle, determine the first target consumption power, wherein the current working condition comprises at least one of the current brake pedal opening, the current environmental temperature, and the water temperature of the current thermal management system.

9. The brake control method of a vehicle according to claim 1, characterized by The method further comprises: In the case that the battery feedback power is limited, determine a second target consumption power; According to the second target consumption power, control the generator of the vehicle to perform reverse drag braking on the engine of the vehicle.

10. The brake control method of a vehicle according to claim 9, characterized by When the drive motor drives the vehicle to travel based on the first target efficiency, the generator works based on a third target efficiency; The determination of the second target consumption power comprises: According to the rotational speed and torque of the generator, and a fourth target efficiency, determine the second target consumption power; Wherein, the efficiency corresponding to the third target efficiency is greater than the efficiency corresponding to the fourth target efficiency.

11. The brake control method of a vehicle according to claim 10, characterized by The third target efficiency is obtained by looking up a third efficiency MAP, which is obtained based on the maximum torque current ratio to calibrate the working efficiency of the generator; The fourth target efficiency is obtained by looking up a fourth efficiency MAP, which is obtained based on the minimum torque current ratio to calibrate the working efficiency of the generator.

12. The brake control method of a vehicle according to claim 1, characterized by The first target efficiency is obtained by looking up a first efficiency map, which is obtained by calibrating the working efficiency of the drive motor based on a maximum torque-current ratio; The second target efficiency is obtained by looking up a second efficiency map, which is obtained by calibrating the working efficiency of the drive motor based on a minimum torque-current ratio.

13. A brake control device of a vehicle characterized by comprising: The device comprises: The judging module is configured to, when the drive motor drives the vehicle to travel based on the first target efficiency, judge whether the battery feedback power is limited in response to a deceleration instruction; The control module is configured to, when the battery feedback power is limited, control the drive motor to brake feedback based on the second target efficiency. The first target efficiency is greater than the second target efficiency.

14. A vehicle characterized by comprising: A computer program product comprising a processor, a memory, and a computer program stored on the memory and executable on the processor, the computer program, when executed by the processor, implements the steps of the method of any one of claims 1-12.

15. An electronic device, comprising: A computer program product comprising a memory and a processor, the memory storing a computer program, the processor, when executing the computer program, implements the steps of the method of any one of claims 1-12.

16. A computer readable storage medium characterized by: A computer program product comprising a memory and a processor, the memory storing a computer program, the processor, when executing the computer program, implements the steps of the method of any one of claims 1-12.

17. A computer program product, characterised in that, A computer program product comprising a memory and a processor, the memory storing a computer program, the processor, when executing the computer program, implements the steps of the method of any one of claims 1-12. A computer program product comprising a memory and a processor, the memory storing a computer program, the processor, when executing the computer program, implements the steps of the method of any one of claims 1-12.

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