Braking energy recovery control method, device, control system, vehicle and medium

Abstract

The present application provides a brake energy recovery control method, device, control system, vehicle, and medium. The method includes: when a vehicle meets preset energy recovery conditions, determining a required braking torque based on a pre-stored correspondence between the vehicle's brake pedal movement depth and braking torque; determining a desired electric motor braking torque and a desired hydraulic braking torque based on a preset principle for prioritizing electric motor braking torque allocation, a maximum energy recovery torque limit, and the required braking torque; determining a target allocation ratio that maximizes the sum of the recovered power of the front motor and the recovered power of the rear motor based on the expected electric motor braking torque, the real-time speed and efficiency of the vehicle's front motor, and the real-time speed and efficiency of the vehicle's rear motor; and distributing the torque between the front motor and the rear motor based on the target allocation ratio, thereby facilitating braking energy recovery at maximum power and improving braking energy recovery efficiency.

Description

Technical Field

[0001] The present invention relates to the field of vehicle braking technology, and in particular to a braking energy recovery control method, device, control system, vehicle and medium. Background Art

[0002] With the global energy crisis and increasingly severe environmental issues, hybrid vehicles are becoming increasingly popular. As a key technology in hybrid vehicles, brake energy regeneration can effectively reduce fuel consumption, improve fuel economy, and increase the vehicle's pure electric range.

[0003] At present, there are solutions for braking energy recovery, but the efficiency of energy recovery still needs to be improved. For example, the Chinese patent with publication number CN102897041B discloses a method for distributing regenerative braking torque in a four-wheel drive hybrid system. Among them, the vehicle controller controls the braking energy recovery based on various data parameters of the ISG motor, rear drive motor and ABS, as well as vehicle speed information, vehicle gear information, accelerator pedal amplitude information and brake pedal information received through data acquisition. However, the content disclosed in this patent focuses on the control of braking energy recovery when there is a partial fault in the vehicle, and does not mention the method for distributing the braking energy recovery torque when the system is normal, and cannot ensure the maximum efficiency of braking energy recovery. Summary of the Invention

[0004] In view of this, the purpose of the embodiments of the present application is to provide a braking energy recovery control method, device, control system, vehicle and medium, which can help the vehicle to achieve braking energy recovery with maximum efficiency.

[0005] To achieve the above technical objectives, the technical solutions adopted in this application are as follows:

[0006] In a first aspect, an embodiment of the present application provides a braking energy recovery control method, the method comprising:

[0007] When the vehicle meets the preset energy recovery conditions, the required braking torque T corresponding to the current movement depth of the brake pedal when performing the braking operation is determined based on the pre-stored correspondence between the movement depth of the brake pedal of the vehicle and the braking torque. TotBrk ;

[0008] Based on the preset principle of prioritizing the distribution of motor torque, the maximum torque limit of energy recovery T Max and the required braking torque T TotBrk , determine the desired motor torque T MtrBrk and the desired hydraulic braking torque T MecBrk , and satisfies T TotBrk =T MtrBrk+T MecBrk , and the desired motor torque T MtrBrk ≤T Max ;

[0009] Based on the expected motor torque T MtrBrk , the real-time speed n of the front drive motor of the vehicle Front and efficiency η Front , the real-time speed n of the rear drive motor of the vehicle Rear and efficiency η Rear , determining a target allocation ratio that maximizes the sum of the regenerative power of the front drive motor and the regenerative power of the rear drive motor;

[0010] Based on the target distribution ratio and the expected motor torque T MtrBrk , determine the expected braking torque T of the front drive motor Front and the desired braking torque T of the rear drive motor Rear ;

[0011] Based on the expected braking torque T of the front motor Front , the desired braking torque T of the rear drive motor Rear , respectively controlling the front drive motor and the rear drive motor to perform energy recovery, and based on the desired hydraulic braking torque T MecBrk The hydraulic brake mechanism of the vehicle is controlled to perform braking.

[0012] In combination with the first aspect, in some optional implementations, based on the preset principle of prioritizing the distribution of motor torque, the maximum torque limit of energy recovery T Max and the required braking torque T TotBrk , determine the desired motor torque T MtrBrk and the desired hydraulic braking torque T MecBrk ,include:

[0013] When the required braking torque T TotBrk Greater than the maximum torque limit T Max When the desired motor torque T is determined MtrBrk =T Max , the desired hydraulic braking torque T MecBrk =T TotBrk -T Max ;

[0014] When the required braking torque T TotBrk Less than or equal to the maximum torque limit T Max When the desired motor torque T is determined MtrBrk =T TotBrk , the desired hydraulic braking torque T MecBrk =0.

[0015] In combination with the first aspect, in some optional implementations, based on the desired motor torque T MtrBrk , the real-time speed n of the front drive motor Front and efficiency η Front , the real-time speed n of the rear drive motor Rear and efficiency η Rear , determining a target allocation ratio that maximizes the sum of the regenerative power of the front drive motor and the regenerative power of the rear drive motor, comprising:

[0016] Based on the preset value range of the distribution ratio, multiple groups of distribution ratios r are selected from the preset value range according to the preset gradient. Front 、r Rear , where r Front Refers to the distribution ratio of the front drive motor, r Rear Refers to the distribution ratio of the rear drive motor. In the same group of distribution ratios, r Front 、r Rear The sum of is 100%;

[0017] According to the expected braking torque T under each group distribution ratio Front , the desired braking torque T Rear , the real-time speed n of the front drive motor Front and efficiency η Front , the real-time speed n of the rear drive motor Rear and efficiency η Rear , determine the total recovery power under each group allocation ratio;

[0018] From the total recovery power of each allocation ratio under the multiple groups of allocation ratios, the allocation ratio corresponding to the maximum total recovery power is selected as the target allocation ratio.

[0019] In combination with the first aspect, in some optional embodiments, the preset value range is 0 to 100%, the preset gradient is 1%, and the multi-group allocation ratio (r Front , r Rear ) The values ​​of each group are (0,100%), (1%,99%),…, (100%,0).

[0020] In conjunction with the first aspect, in some optional implementations, the method further includes:

[0021] Get the actual braking torque T of the front drive motor ActF and the actual braking torque T of the rear drive motor ActR , and the sum of the actual braking torques T is obtained ActTot =T ActF +T ActR ;

[0022] When the desired motor torque T MtrBrk >T ActTot When the hydraulic brake mechanism is controlled to provide insufficient electric braking torque T BrkDif =T MtrBrk -T ActTot make compensation;

[0023] When the desired motor torque T MtrBrk ≤T ActTot , and the desired hydraulic braking torque T MecBrk ≥T ActTot -T MtrBrk When the motor torque T exceeds ActTot -T MtrBrk , control the hydraulic brake mechanism to reduce the desired motor torque T MtrBrk Output.

[0024] In combination with the first aspect, in some optional embodiments, based on the pre-stored correspondence between the movement depth of the brake pedal of the vehicle and the braking torque, the required braking torque T corresponding to the current movement depth of the brake pedal when performing the braking operation is determined. TotBrk Previously, the method also included:

[0025] Acquire a vehicle status data set, the status data set including gear information, vehicle speed, first status information of a front-drive motor, second status information of a rear-drive motor, third status information of a power battery, and fourth status information of a braking system;

[0026] Based on the status data set, it is determined whether the vehicle meets the energy recovery condition, wherein when the gear information indicates that the vehicle is in a forward gear, and the vehicle speed exceeds a preset rate, and the third state indicates that the power battery has no fault, and the fourth state information indicates that the braking system has no fault, and the first state information indicates that the front drive motor has no fault or the second state information indicates that the rear drive motor has no fault, it is determined that the energy recovery condition is met.

[0027] In combination with the first aspect, in some optional embodiments, based on the pre-stored correspondence between the movement depth of the brake pedal of the vehicle and the braking torque, the required braking torque T corresponding to the current movement depth of the brake pedal when performing the braking operation is determined. TotBrk Previously, the method also included:

[0028] Get the maximum recovery torque T of the front drive motor MaxF , the maximum recovery torque T of the rear drive motor MaxR , the maximum charging power P of the power battery on the vehicle BatMax ;

[0029] Based on the maximum recovery torque T MaxF , the maximum recovery torque T MaxR and the maximum charging power P BatMax , determine the maximum torque limit T for motor braking Max , where T Max =min(T MaxF +T MaxR ,9550P BatMax / n), where n refers to the equivalent motor speed of the vehicle at the current speed.

[0030] In a second aspect, an embodiment of the present application further provides a braking energy recovery control device, the device comprising:

[0031] The first determining unit is configured to determine, when the vehicle meets a preset energy recovery condition, a required braking torque T corresponding to the current movement depth of the brake pedal when performing a braking operation based on a pre-stored correspondence between the movement depth of the brake pedal of the vehicle and the braking torque. TotBrk ;

[0032] The second determining unit is used to determine the maximum torque limit of energy recovery based on the preset principle of prioritizing the distribution of motor torque and the maximum torque limit of energy recovery. Max and the required braking torque T TotBrk , determine the desired motor torque T MtrBrk and the desired hydraulic braking torque T MecBrk , and satisfies T TotBrk =T MtrBrk +T MecBrk , and the desired motor torque T MtrBrk ≤T Max ;

[0033] The third determining unit is configured to determine the motor torque T based on the desired motor torque T MtrBrk , the real-time speed n of the front drive motor of the vehicle Front and efficiency η Front , the real-time speed n of the rear drive motor of the vehicle Rear and efficiency η Rear , determining a target allocation ratio that maximizes the sum of the regenerative power of the front drive motor and the regenerative power of the rear drive motor;

[0034] The fourth determining unit is configured to determine the target distribution ratio and the expected motor torque T MtrBrk , determine the expected braking torque T of the front drive motor Front and the desired braking torque T of the rear drive motor Rear ;

[0035] A control unit for determining a desired braking torque T based on the front motor Front , the desired braking torque T of the rear drive motor Rear , respectively controlling the front drive motor and the rear drive motor to perform energy recovery, and based on the desired hydraulic braking torque T MecBrk The hydraulic brake mechanism of the vehicle is controlled to perform braking.

[0036] In a third aspect, an embodiment of the present application further provides a control system, which includes a processing module and a storage module coupled to each other, wherein a computer program is stored in the storage module. When the computer program is executed by the processing module, the control system executes the above method.

[0037] In conjunction with the third aspect, in some optional implementations, the control system further includes:

[0038] A battery management system, a brake system and a brake pedal, wherein the processing module is electrically connected to sensors in the battery management system, the brake system and the brake pedal.

[0039] In conjunction with the third aspect, in some optional implementations, the processing module includes: a powertrain controller, a front drive motor controller, a rear drive motor controller, and a gear controller;

[0040] The powertrain controller is used to receive a signal set from the front-wheel drive motor controller, the rear-wheel drive motor controller, the battery management system, the braking system, the brake pedal and the gear controller, and integrate the signal set to control brake energy recovery.

[0041] In a fourth aspect, an embodiment of the present application further provides a vehicle, comprising a vehicle body and the above-mentioned control system, wherein the control system is arranged on the vehicle body.

[0042] In a fifth aspect, an embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program runs on a computer, the computer executes the above method.

[0043] The invention adopting the above technical solution has the following advantages:

[0044] In the technical solution provided by this application, when the vehicle meets the preset energy recovery conditions, the required braking torque T corresponding to the current movement depth of the brake pedal when performing the braking operation is calculated. TotBrk In this way, the reliability and safety of brake energy recovery can be improved; based on the preset principle of priority distribution of motor torque and the maximum torque limit of energy recovery T Max and required braking torque TTotBrk , determine the desired motor torque T MtrBrk and the desired hydraulic braking torque T MecBrk , and calculate the target distribution ratio that maximizes the sum of the recovery power of the front motor and the recovery power of the rear motor, based on the expected braking torque T of the front motor Front , the expected braking torque T of the rear drive motor Rear , respectively control the front drive motor and rear drive motor to recover energy, and based on the expected hydraulic braking torque T MecBrk Controlling the vehicle's hydraulic brake mechanism to brake. In this way, torque distribution between the front and rear drive motors is performed based on the target distribution ratio, which is conducive to maximum power recovery and can improve the efficiency of brake energy recovery. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The present application may be further illustrated by the non-limiting embodiments provided in the accompanying drawings. It should be understood that the following drawings illustrate only certain embodiments of the present application and are therefore not to be construed as limiting the scope of the present application. It is understood that a person skilled in the art can derive other relevant drawings from these drawings without inventive effort.

[0046] Figure 1 A block diagram of a control system provided in an embodiment of the present application.

[0047] Figure 2 A flow chart of the braking energy recovery control method provided in an embodiment of the present application.

[0048] Figure 3 A schematic diagram of the control logic flow of the braking energy recovery control method provided in an embodiment of the present application.

[0049] Icons: 10-control system; 11-powertrain controller; 12-front-wheel drive motor controller; 13-rear-wheel drive motor controller; 14-battery management system; 15-braking system; 16-accelerator pedal; 17-brake pedal; 18-gear controller. DETAILED DESCRIPTION

[0050] The present application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that similar or identical parts in the drawings or descriptions are numbered the same. Implementations not shown or described in the drawings are known to those of ordinary skill in the art. In the description of this application, the terms "first," "second," etc. are used solely to distinguish descriptions and are not to be construed as indicating or implying relative importance.

[0051] Please refer to Figure 1The present invention provides a control system 10, which may include a processing module and a storage module. The storage module stores a computer program that, when executed by the processing module, enables the control system 10 to perform the corresponding steps of the following braking energy recovery control method.

[0052] The control system 10 can be deployed in a four-wheel drive hybrid vehicle or an electric vehicle including at least four drive motors. There is no specific limitation on the application scenario of the control system 10. The control system 10 can perform brake energy recovery control on the drive motors in the vehicle.

[0053] In this embodiment, the control system 10 may further include: a battery management system 14, a braking system 15, an accelerator pedal 16 and a brake pedal 17, and the processing module is electrically connected to the battery management system 14, the braking system 15, the sensors in the accelerator pedal 16, and the sensors in the brake pedal 17.

[0054] The processing module may include: a powertrain controller 11 , a front drive motor controller 12 , a rear drive motor controller 13 and a gear controller 18 .

[0055] The powertrain controller 11 is used to receive signal sets from the front-wheel drive motor controller 12, the rear-wheel drive motor controller 13, the battery management system 14, the braking system 15, the brake pedal 17 and the gear controller 18, and integrate the signal sets to control the braking energy recovery.

[0056] It is understandable that the powertrain controller 11 can calculate the maximum torque limit value T of the braking energy recovery according to the signal set. Max , the electric motor torque T of the brake system 15 MtrBrk The front and rear axles are distributed, and the front drive motor controller 12 and the rear drive motor controller 13 are controlled to execute the corresponding requested torque.

[0057] The front drive motor controller 12 can receive the signal from the powertrain controller 11 and execute the front drive motor torque T Front , and the actual front drive motor braking torque T is fed back ActF .

[0058] The rear drive motor controller 13 can receive the signal from the powertrain controller 11 and execute the rear drive motor torque T Rear , and feedback of the actual rear drive motor braking torque T ActR .

[0059] The braking system 15 can receive signals from the powertrain controller 11 and the sensor of the brake pedal 17, and calculate the required braking torque T of the driver / vehicle based on the movement depth collected by the sensor of the brake pedal 17.TotBrk , according to the maximum torque limit T of the braking energy recovery of the powertrain controller 11 Max Motor torque T MtrBrk and hydraulic braking torque T MecBrk When the actual motor torque is insufficient, the hydraulic brake mechanism in the brake system 15 needs to be controlled to compensate.

[0060] The gear controller 18 can be used to obtain gear status information, such as forward gear, reverse gear, etc.

[0061] In this embodiment, the storage module may be, but is not limited to, a random access memory, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an electrically erasable programmable read-only memory, etc. In this embodiment, the storage module may be used to store preset energy recovery conditions, vehicle gear information, vehicle speed, first state information of the front-drive motor, second state information of the rear-drive motor, third state information of the power battery, and fourth state information of the braking system 15. Of course, the storage module may also be used to store programs, and the processing module executes the programs after receiving execution instructions.

[0062] It is understandable that Figure 1 The control system 10 structure shown in FIG is only a schematic diagram of a structure, and the control system 10 may also include Figure 1 More or fewer components as shown. Figure 1 Each component shown in the figure can be implemented by hardware, software or a combination thereof.

[0063] It should be noted that, those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the control system 10 described above can refer to the corresponding processes of each step in the following braking energy recovery control method, and will not be elaborated here.

[0064] Please refer to Figure 2 The present application also provides a braking energy recovery control method, which can be applied to the above-mentioned control system 10, and the control system 10 executes or implements each step of the method. The braking energy recovery control method can include the following steps:

[0065] Step 110: When the vehicle meets the preset energy recovery conditions, the required braking torque T corresponding to the current movement depth of the brake pedal when performing the braking operation is determined based on the pre-stored correspondence between the movement depth of the brake pedal of the vehicle and the braking torque. TotBrk ;

[0066] Step 120: Based on the preset principle of prioritizing the distribution of motor torque and the maximum torque limit of energy recovery T Max and the required braking torque TTotBrk , determine the desired motor torque T MtrBrk and the desired hydraulic braking torque T MecBrk , and satisfies T TotBrk =T MtrBrk +T MecBrk , and the desired motor torque T MtrBrk ≤T Max ;

[0067] Step 130: Based on the desired motor torque T MtrBrk , the real-time speed n of the front drive motor of the vehicle Front and efficiency η Front , the real-time speed n of the rear drive motor of the vehicle Rear and efficiency η Rear , determining a target allocation ratio that maximizes the sum of the regenerative power of the front drive motor and the regenerative power of the rear drive motor;

[0068] Step 140: Based on the target distribution ratio and the expected motor torque T MtrBrk , determine the expected braking torque T of the front drive motor Front and the desired braking torque T of the rear drive motor Rear ;

[0069] Step 150: Based on the expected braking torque T of the front drive motor Front , the desired braking torque T of the rear drive motor Rear , respectively controlling the front drive motor and the rear drive motor to perform energy recovery, and based on the desired hydraulic braking torque T MecBrk The hydraulic brake mechanism of the vehicle is controlled to perform braking.

[0070] The following will be combined Figure 2 and Figure 3 , each step of the braking energy recovery control method is described in detail as follows:

[0071] Before step 110, the method may further include the step of detecting whether the vehicle meets a preset energy recovery condition. For example, before step 110, the method may further include:

[0072] Acquire a vehicle status data set, the status data set including gear information, vehicle speed, first status information of a front-drive motor, second status information of a rear-drive motor, third status information of a power battery, and fourth status information of a braking system;

[0073] determining, based on the state data set, whether the vehicle satisfies the energy recovery condition, wherein the energy recovery condition is determined to be satisfied when the gear information indicates that the vehicle is in a forward gear, the vehicle speed exceeds a preset rate, the third state indicates that the power battery is not faulty, the fourth state information indicates that the braking system is not faulty, and the first state information indicates that the front drive motor is not faulty or the second state information indicates that the rear drive motor is not faulty;

[0074] When the gear information indicates that the vehicle is not in the forward gear, or the vehicle speed does not exceed the preset rate, or the third state indicates that the power battery is faulty, or the fourth state information indicates that the braking system is faulty, or the first state information indicates that the front drive motor is faulty and the second state information indicates that the rear drive motor is faulty, it is determined that the energy recovery condition is not met.

[0075] Please refer again Figure 3 In this embodiment, the state data set is obtained in a conventional manner. For example, the powertrain controller may obtain gear information from the vehicle's gear controller, vehicle speed from the vehicle's instrument panel, first state information of the front-drive motor from the front-drive motor controller, second state information of the rear-drive motor from the rear-drive motor controller, third state information of the power battery from the battery management system, and fourth state information of the brake system from the brake system. Each type of state information indicates whether a current electronic component is faulty. For example, the first state information includes information indicating whether a fault exists in the front-drive motor.

[0076] In this embodiment, the preset rate is a relatively low vehicle speed and can be flexibly set based on actual conditions. For example, the preset rate could be 2 km / h. The control system can collect various vehicle data to comprehensively determine whether the energy recovery conditions are met. This helps improve the safety and reliability of subsequent energy recovery and avoids potential safety hazards caused by braking energy recovery when the energy recovery conditions are not met. For example, if braking energy recovery is still performed after a power battery failure, it can easily damage the power battery, thereby affecting driving safety.

[0077] Before step 110 , the method may further include calculating the maximum recovery torque T of the motor braking energy recovery. MaxF steps.

[0078] For example, before step 110, the method may further include:

[0079] Get the maximum recovery torque T of the front drive motor MaxF , the maximum recovery torque T of the rear drive motor MaxR , the maximum charging power P of the power battery on the vehicleBatMax ;

[0080] Based on the maximum recovery torque T MaxF , the maximum recovery torque T MaxR and the maximum charging power P BatMax , determine the maximum torque limit T for motor braking Max , where T Max =min(T MaxF +T MaxR ,9550P BatMax / n), n refers to the equivalent motor speed of the vehicle at the current speed, and n can be flexibly determined according to actual conditions. When the vehicle speed is very low (for example, the vehicle speed is less than 5 km / h), n can be a preset value.

[0081] It can be understood that the maximum recovery torque T of the front motor MaxF , Maximum recovery torque of rear drive motor T MaxR , and the maximum charging power P of the power battery BatMax It is usually a pre-calibrated value and can be pre-stored in the storage module. The control system can obtain the maximum recovery torque T of the front drive motor from the local MaxF , Maximum recovery torque of rear drive motor T MaxR , and the maximum charging power P of the power battery BatMax .

[0082] In this embodiment, the formula T Max =min(T MaxF +T MaxR ,9550P BatMax / n), the maximum torque limit of the motor brake can be calculated T Max , so that the expected motor torque T can be calculated to avoid MtrBrk Exceeding the sum of the maximum output torques of the front and rear motors, and avoiding the desired motor braking torque T MtrBrk , exceeds the maximum charging power P of the power battery BatMax The corresponding torque makes the charging power too large, wherein the excessive charging power can easily damage the power battery.

[0083] In step 110, the control system may pre-store a corresponding relationship between the travel depth of the brake pedal and the braking torque. This corresponding relationship may be a relationship table or a relationship curve, that is, different travel depths correspond to different braking torques. When the current travel depth during the braking operation is detected by the brake pedal sensor, the powertrain controller can obtain the braking torque corresponding to the current travel depth based on this corresponding relationship as the required braking torque T. TotBrk .

[0084] In step 120, based on the preset principle of prioritizing the distribution of motor torque, the maximum torque limit of energy recovery T Max and the required braking torque T TotBrk , determine the desired motor torque T MtrBrk and the desired hydraulic braking torque T MecBrk , which may include:

[0085] When the required braking torque T TotBrk Greater than the maximum torque limit T Max When the desired motor torque T is determined MtrBrk =T Max , the desired hydraulic braking torque T MecBrk =T TotBrk -T Max ;

[0086] When the required braking torque T TotBrk Less than or equal to the maximum torque limit T Max When the desired motor torque T is determined MtrBrk =T TotBrk , the desired hydraulic braking torque T MecBrk =0.

[0087] In this embodiment, the principle of prioritizing the allocation of motor braking torque can be understood as follows: when the required braking torque T TotBrk The maximum torque limit T is not reached Max Before, the braking torque T TotBrk The full amount is allocated to the motor (front drive motor and / or rear drive motor). At this time, no torque is allocated to the hydraulic brake mechanism. When the required braking torque T TotBrk Exceeding the maximum torque limit T Max After that, the motor's quota torque is fully allocated, that is, the expected motor torque T MtrBrk =T Max , then the maximum torque limit T Max The torque is distributed to the hydraulic brake mechanism as hydraulic braking torque.

[0088] In this embodiment, step 130 may include:

[0089] Based on the preset value range of the distribution ratio, multiple groups of distribution ratios r are selected from the preset value range according to the preset gradient. Front 、r Rear , where r Front Refers to the distribution ratio of the front drive motor, r Rear Refers to the distribution ratio of the rear drive motor. In the same group of distribution ratios, r Front 、r Rear The sum of is 100%;

[0090] According to the expected braking torque T under each group distribution ratio Front , the desired braking torque T Rear , the real-time speed n of the front drive motor Front and efficiency η Front , the real-time speed n of the rear drive motor Rear and efficiency η Rear , determine the total recovery power under each group allocation ratio;

[0091] From the total recovery power of each allocation ratio under the multiple groups of allocation ratios, the allocation ratio corresponding to the maximum total recovery power is selected as the target allocation ratio.

[0092] It can be understood that the smaller the preset gradient is, the more groups of distribution ratios are divided, and the greater the maximum total recovery power of the calculated target distribution ratio is.

[0093] As an example, the preset value range is 0 to 100%, and the preset gradient is 1%. At this time, a total of 101 groups of distribution ratios (r Front , r Rear ), each group distribution ratio r Front Refers to the percentage of the front drive motor torque, r Rear , refers to the percentage of the torque of the rear drive motor, and satisfies r Front +r Rear =100%. The values ​​of each group can be (0, 100%), (1%, 99%), ..., (100%, 0). Then, calculate the front drive motor recovery power P corresponding to each group allocation ratio iFront and the rear drive motor recovery power P iRear , i represents the number of groups of distribution ratio, i can be taken from 0 to 100 in sequence, and then through the formula max(P 0Front +P 0Rear ,…,P iFront +P iRear ,…,P 100Front +P 100Rear ), calculate the allocation ratio with the largest recovery power as the target allocation ratio (r FrontPmax , r RearPmax ).

[0094] In step 140, the powertrain controller may calculate the target distribution ratio (r FrontPmax , r RearPmax ) and the desired motor torque T MtrBrk , calculate the expected braking torque T of the front drive motor Front =T MtrBrk *r FrontPmax, and the desired braking torque T of the rear drive motor Rear =T MtrBrk *r RearPmax =T MtrBrk -T Front , and the desired braking torque T of the front drive motor Fron and the desired braking torque T of the rear drive motor Rear The signals are sent to the front motor controller and the rear motor controller respectively to perform torque control of the corresponding motors in step 150 .

[0095] In step 150 , the front motor controller may calculate the braking torque based on the desired braking torque T Front Control the front drive motor to make the torque output by the front drive motor equal to the desired braking torque T Front The same or close to the braking energy recovery. If the desired braking torque T Front If it is 0, there is no need to control the front drive motor for braking energy recovery.

[0096] The rear drive motor controller can be based on the desired braking torque T Rear Control the rear drive motor to make the torque output by the rear drive motor equal to the desired braking torque T Rear The same or close to the braking energy recovery. If the desired braking torque T Rear If it is 0, there is no need to control the rear drive motor for braking energy recovery.

[0097] The braking system can be based on the desired hydraulic braking torque T MecBrk Control the operation of the hydraulic brake mechanism so that the torque output by the hydraulic brake mechanism is consistent with the desired hydraulic braking torque T MecBrk Same or close. If the desired hydraulic braking torque T MecBrk If it is 0, there is no need to control the hydraulic brake mechanism to perform the braking operation.

[0098] In this embodiment, the method may further include:

[0099] Get the actual braking torque T of the front drive motor ActF and the actual braking torque T of the rear drive motor ActR , and the sum of the actual braking torques T is obtained ActTot =T ActF +T ActR ;

[0100] When the desired motor torque T MtrBrk >T ActTot When the hydraulic brake mechanism is controlled to provide insufficient electric braking torque T BrkDif =T MtrBrk -T ActTot make compensation;

[0101] When the desired motor torque T MtrBrk ≤T ActTot , and the desired hydraulic braking torque T MecBrk ≥T ActTot -T MtrBrk When the motor torque T exceeds ActTot -T MtrBrk , control the hydraulic brake mechanism to reduce the desired motor torque T MtrBrk Output.

[0102] Please refer again Figure 3 , it can be understood that the front motor controller and the rear motor controller can provide real-time feedback of the actual braking torque T performed by the front motor. ActF and the actual braking torque T of the rear drive motor ActR To the braking system, the braking system determines the sum of the braking torques T provided by the front and rear drive motors ActTot =T ActF +T ActR Does not meet the expected motor torque T MtrBrk When the braking system needs to control the hydraulic braking mechanism to respond to the insufficient electric braking torque T BrkDif =T MtrBrk -T ActTot Make compensation.

[0103] In addition, when the hydraulic brake mechanism also participates in braking, and the sum of the braking torques provided by the front and rear drive motors exceeds the expected motor braking torque T MtrBrk , and the expected hydraulic braking torque T MecBrk ≥T ActTot -T MtrBrk When the desired hydraulic braking torque output is reduced, the amount of torque reduction is ΔT = T ActTot -T MtrBrk In this way, the front and rear drive motors can avoid excessive torque output, which may affect the stability of vehicle braking.

[0104] Based on the above design, the powertrain controller or the processor in the braking system calculates the driver's braking torque demand and distributes the electric braking torque and the hydraulic braking torque, which not only ensures the braking safety of the vehicle but also maximizes the recovery of braking energy; the powertrain controller calculates the maximum distribution ratio of recovered power based on the expected electric braking torque, the speed and efficiency of the front / rear drive motors and different distribution ratios, and distributes the front and rear electric braking torques. This is conducive to energy recovery with the maximum recovery power, which can increase the energy of the four-wheel drive hybrid system's braking energy recovery and further improve the efficiency of energy recovery.

[0105] The present application also provides a braking energy recovery control device, comprising at least one software function module that can be stored in a storage module in the form of software or firmware, or embedded in an operating system (OS). A processing module is configured to execute executable modules stored in the storage module, such as the software function modules and computer programs included in the braking energy recovery control device.

[0106] The braking energy recovery control device includes the following units:

[0107] The first determining unit is configured to determine, when the vehicle meets a preset energy recovery condition, a required braking torque T corresponding to the current movement depth of the brake pedal when performing a braking operation based on a pre-stored correspondence between the movement depth of the brake pedal of the vehicle and the braking torque. TotBrk ;

[0108] The second determining unit is used to determine the maximum torque limit of energy recovery based on the preset principle of prioritizing the distribution of motor torque and the maximum torque limit of energy recovery. Max and the required braking torque T TotBrk , determine the desired motor torque T MtrBrk and the desired hydraulic braking torque T MecBrk , and satisfies T TotBrk =T MtrBrk +T MecBrk , and the desired motor torque T MtrBrk ≤T Max ;

[0109] The third determining unit is configured to determine the motor torque T based on the desired motor torque T MtrBrk , the real-time speed n of the front drive motor of the vehicle Front and efficiency η Front , the real-time speed n of the rear drive motor of the vehicle Rear and efficiency η Rear , determining a target allocation ratio that maximizes the sum of the regenerative power of the front drive motor and the regenerative power of the rear drive motor;

[0110] The fourth determining unit is configured to determine the target distribution ratio and the expected motor torque T MtrBrk , determine the expected braking torque T of the front drive motor Front and the desired braking torque T of the rear drive motor Rear ;

[0111] A control unit for determining a desired braking torque T based on the front motor Front , the desired braking torque T of the rear drive motor Rear, respectively controlling the front drive motor and the rear drive motor to perform energy recovery, and based on the desired hydraulic braking torque T MecBrk The hydraulic brake mechanism of the vehicle is controlled to perform braking.

[0112] Optionally, the second determining unit may be specifically configured to: when the required braking torque T TotBrk Greater than the maximum torque limit T Max When the desired motor torque T is determined MtrBrk =T Max , the desired hydraulic braking torque T MecBrk =T TotBrk -T Max ;

[0113] When the required braking torque T TotBrk Less than or equal to the maximum torque limit T Max When the desired motor torque T is determined MtrBrk =T TotBrk , the desired hydraulic braking torque T MecBrk =0.

[0114] Optionally, the third determining unit may be specifically configured to:

[0115] Based on the preset value range of the distribution ratio, multiple groups of distribution ratios r are selected from the preset value range according to the preset gradient. Front 、r Rear , where r Front Refers to the distribution ratio of the front drive motor, r Rear Refers to the distribution ratio of the rear drive motor. In the same group of distribution ratios, r Front 、r Rear The sum of is 100%;

[0116] According to the expected braking torque T under each group distribution ratio Front , the desired braking torque T Rear , the real-time speed n of the front drive motor Front and efficiency η Front , the real-time speed n of the rear drive motor Rear and efficiency η Rear , determine the total recovery power under each group allocation ratio;

[0117] From the total recovery power of each allocation ratio under the multiple groups of allocation ratios, the allocation ratio corresponding to the maximum total recovery power is selected as the target allocation ratio.

[0118] Optionally, the braking energy recovery control device may further include a first acquisition unit. The first acquisition unit is configured to acquire the actual braking torque T of the front drive motor. ActFand the actual braking torque T of the rear drive motor ActR , and the sum of the actual braking torques T is obtained ActTot =T ActF +T ActR ;

[0119] The control unit may further be configured to: when the desired motor torque T MtrBrk >T ActTot When the hydraulic brake mechanism is controlled to compensate for the insufficient electric braking torque T BrkDif =T MtrBrk -T ActTot Compensation is performed; and when the desired motor torque T MtrBrk ≤T ActTot , and the desired hydraulic braking torque T MecBrk ≥T ActTot -T MtrBrk When the motor torque T exceeds ActTot -T MtrBrk , control the hydraulic brake mechanism to reduce the desired motor torque T MtrBrk Output.

[0120] Optionally, the braking energy recovery control device may further include a second acquisition unit and a judgment unit. Based on the pre-stored correspondence between the movement depth of the brake pedal of the vehicle and the braking torque, the required braking torque T corresponding to the current movement depth of the brake pedal when performing the braking operation is determined. TotBrk Previously, the second acquisition unit was used to acquire a vehicle status data set, the status data set including gear information, vehicle speed, first status information of the front drive motor, second status information of the rear drive motor, third status information of the power battery, and fourth status information of the braking system;

[0121] The judgment unit is used to judge whether the vehicle meets the energy recovery condition based on the status data set, wherein when the gear information indicates that the vehicle is in a forward gear and the vehicle speed exceeds a preset rate, and the third state indicates that the power battery has no fault, and the fourth state information indicates that the braking system has no fault, and the first state information indicates that the front drive motor has no fault or the second state information indicates that the rear drive motor has no fault, it is determined that the energy recovery condition is met.

[0122] Optionally, the braking energy recovery control device may further include a third acquisition unit and a fifth determination unit. Based on the pre-stored correspondence between the movement depth of the brake pedal of the vehicle and the braking torque, the required braking torque T corresponding to the current movement depth of the brake pedal when performing the braking operation is determined. TotBrk Previously, the third acquisition unit was used to obtain the maximum recovery torque T of the front drive motor.MaxF , the maximum recovery torque T of the rear drive motor MaxR , the maximum charging power P of the power battery on the vehicle BatMax The fifth determining unit is used to determine the maximum recovery torque T MaxF , the maximum recovery torque T MaxR and the maximum charging power P BatMax , determine the maximum torque limit T for motor braking Max , where T Max =min(T MaxF +T MaxR ,9550P BatMax / n), where n refers to the equivalent motor speed of the vehicle at the current speed.

[0123] It should be noted that, those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the braking energy recovery control device described above can refer to the corresponding processes of each step in the following braking energy recovery control method, and will not be elaborated here.

[0124] An embodiment of the present application also provides a vehicle, which may include a vehicle body and the above-mentioned control system. The control system is deployed on the vehicle body. In this way, the vehicle has the functions of the above-mentioned control system, which is beneficial to improving the efficiency of the vehicle in braking energy recovery during braking.

[0125] The present application also provides a computer-readable storage medium that stores a computer program, which, when executed on a computer, causes the computer to execute the braking energy recovery control method described in the above embodiment.

[0126] Through the description of the above implementation methods, those skilled in the art can clearly understand that the present application can be implemented through hardware or by means of software plus a necessary general hardware platform. Based on this understanding, the technical solution of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.), including a number of instructions for enabling a computer device (which can be a personal computer, a control system, or a network device, etc.) to execute the methods described in each implementation scenario of the present application.

[0127] In the embodiments provided in the present application, it should be understood that the disclosed devices, systems and methods can also be implemented in other ways. The device, system and method embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the systems, methods and computer program products according to the multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of code, and a part of the module, program segment or code includes one or more executable instructions for implementing the specified logical function. It should also be noted that each box in the block diagram and / or flowchart, and the combination of the boxes in the block diagram and / or flowchart can be implemented by a dedicated hardware-based system that performs the specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions. In addition, the functional modules in the various embodiments of the present application can be integrated together to form an independent part, or each module can exist alone, or two or more modules can be integrated to form an independent part.

[0128] The above description is merely an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, various modifications and variations of the present application are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A braking energy recovery control method, characterized in that: The method comprises: When the vehicle meets the preset energy recovery conditions, the required braking torque T corresponding to the current movement depth of the brake pedal when performing the braking operation is determined based on the pre-stored correspondence between the movement depth of the brake pedal of the vehicle and the braking torque. TotBrk ; Based on the preset principle of prioritizing the distribution of motor torque, the maximum torque limit of energy recovery T Max and the required braking torque T TotBrk , determine the desired motor torque T MtrBrk and the desired hydraulic braking torque T MecBrk , and satisfies T TotBrk =T MtrBrk +T MecBrk , and the desired motor torque T MtrBrk ≤T Max ; Based on the expected motor torque T MtrBrk , the real-time speed n of the front drive motor of the vehicle Front and efficiency η Front , the real-time speed n of the rear drive motor of the vehicle Rear and efficiency η Rear , determining a target allocation ratio that maximizes the sum of the regenerative power of the front drive motor and the regenerative power of the rear drive motor; Based on the target distribution ratio and the expected motor torque T MtrBrk , determine the expected braking torque T of the front drive motor Front and the desired braking torque T of the rear drive motor Rear ; Based on the expected braking torque T of the front motor Front , the desired braking torque T of the rear drive motor Rear , respectively controlling the front drive motor and the rear drive motor to perform energy recovery, and based on the desired hydraulic braking torque T MecBrk Controlling the hydraulic brake mechanism of the vehicle to brake; Based on the preset principle of prioritizing the distribution of motor torque, the maximum torque limit of energy recovery T Max and the required braking torque T TotBrk , determine the desired motor torque T MtrBrk and the desired hydraulic braking torque T MecBrk ,include: When the required braking torque T TotBrk Greater than the maximum torque limit T Max When the desired motor torque T is determined MtrBrk =T Max , the desired hydraulic braking torque T MecBrk =T TotBrk -T Max ; When the required braking torque T TotBrk Less than or equal to the maximum torque limit T Max When the desired motor torque T is determined MtrBrk =T TotBrk , the desired hydraulic braking torque T MecBrk =0; Based on the expected motor torque T MtrBrk , the real-time speed n of the front drive motor of the vehicle Front and efficiency η Front , the real-time speed n of the rear drive motor of the vehicle Rear and efficiency η Rear , determining a target allocation ratio that maximizes the sum of the regenerative power of the front drive motor and the regenerative power of the rear drive motor, comprising: Based on the preset value range of the distribution ratio, multiple groups of distribution ratios r are selected from the preset value range according to the preset gradient. Front 、r Rear , where r Front Refers to the distribution ratio of the front drive motor, r Rear Refers to the distribution ratio of the rear drive motor. In the same group of distribution ratios, r Front 、r Rear The sum of is 100%; According to the expected braking torque T under each group distribution ratio Front , the desired braking torque T Rear , the real-time speed n of the front drive motor Front and efficiency η Front , the real-time speed n of the rear drive motor Rear and efficiency η Rear , determine the total recovery power under each group allocation ratio; From the total recovered powers of each allocation ratio under the multiple allocation ratios, selecting the allocation ratio corresponding to the maximum total recovered power as the target allocation ratio; The preset value range is 0 to 100%, the preset gradient is 1%, and the multi-group distribution ratio (r Front , r Rear ) The values ​​of each group are (0,100%), (1%,99%),…, (100%,0); The method further comprises: Get the actual braking torque T of the front drive motor ActF and the actual braking torque T of the rear drive motor ActR , and the sum of the actual braking torques T is obtained ActTot =T ActF +T ActR ; When the desired motor torque T MtrBrk >T ActTot When the hydraulic brake mechanism is controlled to provide insufficient electric braking torque T BrkDif =T MtrBrk -T ActTot make compensation; When the desired motor torque T MtrBrk ≤T ActTot , and the desired hydraulic braking torque T MecBrk ≥T ActTot -T MtrBrk When the motor torque T exceeds ActTot -T MtrBrk , control the hydraulic brake mechanism to reduce the desired motor torque T MtrBrk Output.

2. The method according to claim 1, characterized in that Based on the pre-stored correspondence between the movement depth of the brake pedal of the vehicle and the braking torque, the required braking torque T corresponding to the current movement depth of the brake pedal when performing the braking operation is determined. TotBrk Previously, the method also included: Acquire a vehicle status data set, the status data set including gear information, vehicle speed, first status information of a front-drive motor, second status information of a rear-drive motor, third status information of a power battery, and fourth status information of a braking system; Based on the status data set, it is determined whether the vehicle meets the energy recovery condition, wherein when the gear information indicates that the vehicle is in a forward gear, and the vehicle speed exceeds a preset rate, and the third state indicates that the power battery has no fault, and the fourth state information indicates that the braking system has no fault, and the first state information indicates that the front drive motor has no fault or the second state information indicates that the rear drive motor has no fault, it is determined that the energy recovery condition is met.

3. The method according to claim 1, characterized in that Based on the pre-stored correspondence between the movement depth of the brake pedal of the vehicle and the braking torque, the required braking torque T corresponding to the current movement depth of the brake pedal when performing the braking operation is determined. TotBrk Previously, the method also included: Get the maximum recovery torque T of the front drive motor MaxF , the maximum recovery torque T of the rear drive motor MaxR , the maximum charging power P of the power battery on the vehicle BatMax ; Based on the maximum recovery torque T MaxF , the maximum recovery torque T MaxR and the maximum charging power P BatMax , determine the maximum torque limit T for motor braking Max , where T Max =min(T MaxF +T MaxR ,9550P BatMax / n), where n refers to the equivalent motor speed of the vehicle at the current speed.

4. A braking energy recovery control device, characterized in that: The device comprises: The first determining unit is configured to determine, when the vehicle meets a preset energy recovery condition, a required braking torque T corresponding to the current movement depth of the brake pedal when performing a braking operation based on a pre-stored correspondence between the movement depth of the brake pedal of the vehicle and the braking torque. TotBrk ; The second determining unit is used to determine the maximum torque limit of energy recovery based on the preset principle of prioritizing the distribution of motor torque and the maximum torque limit of energy recovery. Max and the required braking torque T TotBrk , determine the desired motor torque T MtrBrk and the desired hydraulic braking torque T MecBrk , and satisfies T TotBrk =T MtrBrk +T MecBrk , and the desired motor torque T MtrBrk ≤T Max ; The third determining unit is configured to determine the motor torque T based on the desired motor torque T MtrBrk , the real-time speed n of the front drive motor of the vehicle Front and efficiency η Front , the real-time speed n of the rear drive motor of the vehicle Rear and efficiency η Rear , determining a target allocation ratio that maximizes the sum of the regenerative power of the front drive motor and the regenerative power of the rear drive motor; The fourth determining unit is configured to determine the target distribution ratio and the expected motor torque T MtrBrk , determine the expected braking torque T of the front drive motor Front and the desired braking torque T of the rear drive motor Rear ; A control unit for determining a desired braking torque T based on the front motor Front , the desired braking torque T of the rear drive motor Rear , respectively controlling the front drive motor and the rear drive motor to perform energy recovery, and based on the desired hydraulic braking torque T MecBrk Controlling the hydraulic brake mechanism of the vehicle to brake; The second determining unit is specifically configured to: when the required braking torque T TotBrk Greater than the maximum torque limit T Max When the desired motor torque T is determined MtrBrk =T Max , the desired hydraulic braking torque T MecBrk =T TotBrk -T Max ; When the required braking torque T TotBrk Less than or equal to the maximum torque limit T Max When the desired motor torque T is determined MtrBrk =T TotBrk , the desired hydraulic braking torque T MecBrk =0; The third determining unit is specifically configured to: based on a preset value range of the allocation ratio, select multiple groups of allocation ratios r from the preset value range according to a preset gradient. Front 、r Rear , where r Front Refers to the distribution ratio of the front drive motor, r Rear Refers to the distribution ratio of the rear drive motor. In the same group of distribution ratios, r Front 、r Rear The sum of the expected braking torque T under each group distribution ratio is 100%; Front , the desired braking torque T Rear , the real-time speed n of the front drive motor Front and efficiency η Front , the real-time speed n of the rear drive motor Rear and efficiency η Rear , determining the total recovery power under each group of allocation ratios; selecting the allocation ratio corresponding to the maximum total recovery power from the total recovery power of each group of allocation ratios under the multiple groups of allocation ratios as the target allocation ratio; The preset value range is 0 to 100%, the preset gradient is 1%, and the multi-group distribution ratio (r Front , r Rear ) The values ​​of each group are (0,100%), (1%,99%),…, (100%,0); The device further includes a first acquisition unit configured to acquire the actual braking torque T of the front drive motor. ActF and the actual braking torque T of the rear drive motor ActR , and the sum of the actual braking torques T is obtained ActTot =T ActF +T ActR ; The control unit is further configured to: when the desired motor torque T MtrBrk >T ActTot When the hydraulic brake mechanism is controlled to compensate for the insufficient electric braking torque T BrkDif =T MtrBrk -T ActTot Compensation is performed; and when the desired motor torque T MtrBrk ≤T ActTot , and the desired hydraulic braking torque T MecBrk ≥T ActTot -T MtrBrk When the motor torque T exceeds ActTot -T MtrBrk , control the hydraulic brake mechanism to reduce the desired motor torque T MtrBrk Output.

5. A control system, characterized in that: The control system includes a processing module and a storage module coupled to each other, wherein the storage module stores a computer program. When the computer program is executed by the processing module, the control system executes the method according to any one of claims 1 to 3.

6. The control system according to claim 5, characterized in that: The control system further comprises: A battery management system, a brake system and a brake pedal, wherein the processing module is electrically connected to sensors in the battery management system, the brake system and the brake pedal.

7. The control system according to claim 6, characterized in that: The processing module includes: a powertrain controller, a front drive motor controller, a rear drive motor controller and a gear controller; The powertrain controller is used to receive a signal set from the front-wheel drive motor controller, the rear-wheel drive motor controller, the battery management system, the braking system, the brake pedal and the gear controller, and integrate the signal set to control brake energy recovery.

8. A vehicle, characterized in that: The vehicle includes a vehicle body and a control system according to any one of claims 5 to 7, wherein the control system is arranged on the vehicle body.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is run on a computer, the computer is caused to execute the method according to any one of claims 1 to 3.

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