Braking energy recovery control method for double electric drive axles

Abstract

The invention discloses a braking energy recovery control method for double electric drive axles, and belongs to the technical field of electric car control, and the braking energy recovery control method for the double electric drive axles is characterized by comprising the following steps: acquiring braking data when a braking pedal moves in real time; the required total braking force is calculated according to the braking data, braking force coefficients are distributed for a front axle and a rear axle, the front axle braking force and the rear axle braking force are obtained, and the rear axle comprises a first electric drive axle and a second electric drive axle; based on the distribution coefficient, the rear axle braking force is distributed into mechanical braking force and recovery braking force; the recycled braking force is converted into direct current, the direct current is charged into a power battery, and the recycled braking force of a motor is collected; and the front axle braking force, the mechanical braking force and the recovery braking force of the motor are distributed to a braking execution system. The problems that in the prior art, the braking energy recovery efficiency is low, and kinetic energy generated in the braking process of a vehicle cannot be fully utilized are solved.

Description

Technical Field

[0001] The invention relates to a braking energy recovery control method for a dual electric drive bridge, belonging to the technical field of electric vehicle control. Background Art

[0002] With the increasing global awareness of energy conservation and emission reduction, pure electric or hybrid vehicles have been widely promoted and used in the market due to their environmental protection and energy-saving characteristics. During the braking process, these new energy vehicles can effectively convert the kinetic energy generated by the vehicle during braking into electrical energy and store it in the vehicle's power battery through advanced motor energy recovery technology. This technology not only significantly increases the vehicle's cruising range, but also effectively improves the market competitiveness of the product. At present, new energy vehicles on the market generally use advanced anti-lock braking systems ABS, which can quickly adjust the braking force of the wheels in emergency braking situations to prevent wheel locking, thereby improving the braking stability and safety of the vehicle.

[0003] Although existing new energy vehicles are generally equipped with ABS systems, there are still obvious deficiencies in brake energy recovery. Traditional ABS system pedals mostly adopt a switch quantity design, that is, there are only two states: on and off. This design makes it impossible for the system to accurately sense the depth of the brake pedal, and thus cannot perform detailed energy recovery calculations based on changes in braking intensity. This limitation leads to low efficiency in brake energy recovery and inability to fully utilize the kinetic energy generated by the vehicle during braking. Therefore, how to overcome the deficiencies of existing ABS systems in brake energy recovery and achieve more accurate and efficient energy recovery has become a key issue that needs to be urgently addressed in the current development of new energy vehicle technology. Summary of the invention

[0004] The purpose of the present invention is to provide a braking energy recovery control method for a dual electric drive axle, which dynamically adjusts the braking force distribution strategy and the motor energy recovery mode by monitoring the braking data, so as to solve the problem that the existing technology has low efficiency in braking energy recovery and cannot fully utilize the kinetic energy generated by the vehicle during braking.

[0005] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions:

[0006] The present invention provides a braking energy recovery control method for a dual electric drive axle, comprising:

[0007] Use the vehicle controller to obtain real-time braking data when the brake pedal moves;

[0008] The braking data includes brake pedal opening, load and vehicle speed;

[0009] Utilizing a front and rear axle braking force distribution system to calculate the required total braking force according to the braking data, and distributing braking force coefficients to the front axle and the rear axle to obtain the front axle braking force and the rear axle braking force, wherein the rear axle includes a first electric drive axle and a second electric drive axle;

[0010] Based on the distribution coefficient, the rear axle braking force is distributed into mechanical braking force and regenerative braking force using the rear wheel brake distribution module;

[0011] Switch the motor controller 1 and the motor controller 2 to the power generation mode, convert the regenerative braking force into direct current through the power converter, charge the power battery and collect the regenerative braking force of the motor;

[0012] Distributes the front axle braking force, mechanical braking force and the electric motor's regenerative braking force to the brake actuation system.

[0013] Furthermore, after calculating the required total braking force, the braking deceleration of the vehicle is calculated according to the required braking force, and the braking mode of the vehicle is divided into slow braking, moderate braking and emergency braking. The braking mode of the vehicle is expressed as:

[0014] ;

[0015] In the formula, Indicates the braking mode of the vehicle. "0" indicates that the braking mode of the vehicle is slow braking, "1" indicates that the braking mode of the vehicle is moderate braking, and "2" indicates that the braking mode of the vehicle is emergency braking. It is the ratio of the vehicle's braking deceleration to the acceleration due to gravity, indicating the braking intensity.

[0016] Furthermore, when the braking mode of the vehicle is slow braking, the front axle braking force is 0, and the rear axle braking force acts on the whole vehicle braking force;

[0017] Wherein, the whole vehicle braking force is expressed as:

[0018] ;

[0019] In the formula, Indicates the vehicle braking force, Indicates the rear axle braking force;

[0020] When the vehicle's braking mode is medium braking, the front axle braking force and the rear axle braking force act together on the vehicle's braking force;

[0021] Wherein, the whole vehicle braking force is expressed as:

[0022] ;

[0023] In the formula, Indicates the front axle braking force;

[0024] When the vehicle's braking mode is emergency braking, the front axle braking force and the rear axle braking force act together on the vehicle's braking force;

[0025] Wherein, the whole vehicle braking force is expressed as:

[0026] .

[0027] Furthermore, the front and rear axle braking force distribution system is used to calculate the required total braking force according to the braking data, and the braking force coefficients are distributed to the front axle and the rear axle to obtain the front axle braking force and the rear axle braking force. The distribution coefficient is expressed as:

[0028] ;

[0029] In the formula, represents the distribution coefficient, represents the braking force coefficient, represents the correction factor, Indicates the front axle braking force, Indicates the rear axle braking force.

[0030] Furthermore, before converting the regenerative braking force into direct current through the power converter, the vehicle controller performs a pre-check, including:

[0031] Confirm that the vehicle has entered a high-pressure state, the current gear, the initial value of the brake pedal opening, the motor speed is working normally, the battery power SOC initial value, and the anti-lock function of the brake execution system has been activated.

[0032] Furthermore, when the vehicle's braking mode is slow braking, if the vehicle enters the upper high-pressure state, the current gear is the forward gear, the brake pedal opening is less than 30%, the motor speed is working normally, and the battery power SOC is less than 95%, the brake execution system enters the motor braking energy recovery mode and requests to collect the motor's recovery braking force;

[0033] The rear axle mechanical braking force and the recovery braking force of the motor act together on the rear axle braking force. The recovery braking force of the motor includes the recovery braking force of the first electric drive axle and the recovery braking force of the second electric drive axle. The rear axle braking force is expressed as:

[0034] ;

[0035] In the formula, Represents the rear axle braking force, Represents the rear axle mechanism power, Indicates the regenerative braking force of the first electric drive axle, Indicates the regenerative braking force of the second electric drive axle.

[0036] Furthermore, when the vehicle's braking mode is medium braking, if the vehicle enters the upper high-pressure state, the current gear is the forward gear, the brake pedal opening is 30%-80%, the motor speed is working normally, and the battery power SOC is less than 95%, the brake execution system enters the motor braking energy recovery mode and requests to collect the motor's recovery braking force;

[0037] The rear axle mechanical braking force and the recovery braking force of the motor act together on the rear axle braking force. The recovery braking force of the motor includes the recovery braking force of the first electric drive axle and the recovery braking force of the second electric drive axle. The rear axle braking force is expressed as:

[0038] ;

[0039] In the formula, Represents the rear axle braking force, Represents the rear axle mechanism power, Indicates the regenerative braking force of the first electric drive axle, Indicates the regenerative braking force of the second electric drive axle.

[0040] Further, the rear axle braking force is converted into torque for control, including:

[0041] setting the brake motor torque requested by the brake actuation system to be less than the maximum available brake torque of the motor;

[0042] The brake execution system collects wheel speed signals in real time to determine whether the vehicle's anti-lock brake execution system ABS is activated:

[0043] If ABS is activated, the brake execution system exits the motor brake energy recovery mode;

[0044] If ABS is not activated, the brake execution system continues to execute the motor braking energy recovery mode and uses the vehicle controller to calculate the recovery torque allowed by the power battery.

[0045] Furthermore, when the vehicle's braking mode is emergency braking, if the entire vehicle enters the upper high-pressure state, the current gear is the forward gear, the brake pedal opening is greater than 80%, the motor speed is working normally, and the battery power SOC is less than 95%, the brake execution system exits the motor braking energy recovery mode and distributes the front axle braking force and the rear axle mechanical braking force as the rear axle braking force.

[0046] Further, according to the different loads, the vehicle is adaptively adjusted to or The drive forms include:

[0047] When the load is within a preset threshold, the motor controller 1 exits the driving mode, the first electric drive axle is kept in an idling state, and the rear axle motor controller controls the rear axle motor and the rear axle gearbox to be engaged in a non-neutral gear to drive the vehicle;

[0048] When the load is not within a preset threshold, the motor controller 1 and the motor controller 2 work simultaneously to respectively control the first electric drive axle and the second electric drive axle and the transmission of the first electric drive axle and the transmission of the second electric drive axle to shift into a non-neutral gear to drive the vehicle.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] 1. The present invention obtains the braking data when the brake pedal moves, including the brake pedal opening, load and vehicle speed, through the vehicle controller, and based on the braking data, calculates and dynamically distributes the braking force coefficients of the front and rear axles through the front and rear axle braking force distribution system, thereby realizing intelligent distribution of the braking force. The present invention innovatively utilizes the rear wheel brake distribution module to subdivide the rear axle braking force into mechanical braking force and recovery braking force according to the distribution coefficient, and efficiently converts the recovery braking force into direct current and charges it into the power battery by switching the rear axle motor controller to the power generation mode, which not only improves the recovery efficiency of the braking energy, but also can flexibly adjust the ratio of the mechanical braking force and the recovery braking force according to the actual braking demand, thereby maximizing the use of the kinetic energy generated by the vehicle during the braking process while ensuring braking safety, effectively extending the cruising range of new energy vehicles, and improving the energy utilization efficiency of the vehicle;

[0051] 2. The present invention divides the braking mode into three modes: slow braking, moderate braking and emergency braking by calculating the braking deceleration of the vehicle in real time. According to the braking intensity under different braking modes, the present invention can accurately distribute the braking force of the front axle and the rear axle, as well as the ratio of mechanical braking force to recovery braking force, which not only ensures the safety and stability of the braking process, but also maximizes the recovery efficiency of braking energy, effectively extending the cruising range of new energy vehicles;

[0052] 3. Before starting the braking energy recovery function, the present invention performs a strict pre-inspection through the vehicle controller, including confirming that the vehicle has entered a high-voltage state, the current gear position, the brake pedal opening, the motor speed, the battery power SOC, and the activation state of the anti-lock function of the brake execution system, which effectively avoids safety hazards caused by abnormal vehicle status and ensures the safety and reliability of the braking energy recovery process.

[0053] 4. The present invention can adaptively adjust the driving mode of the vehicle according to the load condition of the vehicle. When the load is light, the mid-bridge motor controller driving mode is exited and only the rear-bridge motor controller is used to drive the vehicle, so as to reduce energy consumption and improve energy recovery efficiency. When the load is heavy, the mid-bridge motor controller and the rear-bridge motor controller are used to drive the vehicle at the same time to ensure the driving performance and power output of the vehicle. The adaptive driving mode not only optimizes the energy recovery efficiency of the vehicle, but also improves the overall performance and driving experience of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is a schematic diagram of a recovery architecture of a braking energy recovery control method for a dual electric drive axle provided in an embodiment of the present invention;

[0055] Figure 2 is a schematic diagram of a braking energy recovery curve provided by an embodiment of the present invention;

[0056] Figure 3 It is a working schematic diagram of the electric drive bridge provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0057] The technical solution of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations on the technical solution of the present invention. The embodiments of the present invention and the technical features in the embodiments may be combined with each other unless there is a conflict.

[0058] The term "and / or" is only a description of the association relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " generally indicates that the related objects are in an "or" relationship.

[0059] Example 1

[0060] like Figure 1 As shown, this embodiment introduces a braking energy recovery control method for a dual electric drive axle, including:

[0061] Step 1: Use the vehicle controller to obtain real-time braking data when the brake pedal moves.

[0062] The present invention uses the vehicle controller as the central nervous system of the vehicle, which is responsible for collecting and processing data from various sensors. When the driver steps on the brake pedal, the brake pedal position sensor will detect the pedal opening in real time, that is, the depth of the pedal. The pedal opening directly reflects the braking intensity expected by the driver.

[0063] In the present invention, the braking data includes brake pedal opening, load and vehicle speed.

[0064] At the same time, the vehicle load sensor and speed sensor provide information about the vehicle's current load and speed, respectively. The current load and speed information are the basis for the subsequent calculation of the total braking force and distributed braking force required, ensuring that the braking energy recovery process can be intelligently adjusted according to actual driving conditions and needs.

[0065] Step 2: Utilize the front and rear axle braking force distribution system to calculate the required total braking force according to the braking data, and distribute braking force coefficients to the front axle and the rear axle to obtain the front axle braking force and the rear axle braking force.

[0066] In the present invention, the rear axle includes a first electric drive axle and a second electric drive axle. Figure 1 The motor controller 1 shown is the motor controller of the first electric drive bridge. Figure 1 The motor controller 2 shown is a motor controller for the second electric drive bridge.

[0067] The present invention calculates the total braking force required by the vehicle based on the braking data, and reasonably distributes the braking force to the front axle and the rear axle according to the dynamic characteristics of the vehicle and the braking stability requirements. The braking force distribution system is used to dynamically adjust the braking force coefficients of the front axle and the rear axle according to the vehicle's load, speed and brake pedal opening information to ensure stability and safety during braking. This step is the key balance point between braking energy recovery and braking safety. In particular, the braking force distribution system mentioned in the present invention refers to the electronic braking force distribution system EBS.

[0068] Step 3: Based on the distribution coefficient, the rear axle braking force is distributed into mechanical braking force and regenerative braking force using the rear wheel brake distribution module.

[0069] After determining the total braking force required by the rear axle, the present invention uses the rear wheel brake distribution module to divide the ratio of mechanical braking force and recovery braking force according to a preset distribution coefficient. Among them, the mechanical braking force is used to directly decelerate the vehicle, while the recovery braking force is converted into electrical energy and stored by the motor. This step realizes efficient recovery of braking energy and ensures that the braking energy is recovered to the maximum extent without sacrificing braking performance.

[0070] Step 4: Switch the motor controller 1 and the motor controller 2 to the power generation mode, convert the regenerative braking force into direct current through the power converter, charge the power battery and collect the regenerative braking force of the motor.

[0071] The present invention switches the motor controller 1 and the motor controller 2 to the power generation mode. In the power generation mode, the motor is no longer a power source, but becomes a generator. It converts the recovery braking force, that is, the kinetic energy of the vehicle, into electrical energy, and converts the electrical energy into direct current suitable for storage in the power battery through a power converter, such as a DC / DC converter or an inverter. This step realizes the conversion and storage of braking energy, which is the key to extending the vehicle's cruising range.

[0072] Step 5: Distribute the front axle braking force, mechanical braking force and motor recovery braking force to the brake execution system.

[0073] The present invention applies the calculated braking force including the front axle braking force, the rear axle mechanical braking force and the recovery braking force to the brake execution system. The brake execution system includes components such as hydraulic brakes and electronic brake calipers, and the brake execution system brakes the vehicle according to the received braking force command. By reasonably distributing and applying different types of braking force to the wheels, it is ensured that the vehicle can achieve smooth and efficient braking and energy recovery under the premise of ensuring safety.

[0074] In summary, each step mentioned in the present invention is closely connected and together constitutes a complete process of the electric drive axle braking energy recovery control method. This process not only improves the efficiency of braking energy recovery, but also ensures the safety and stability of the braking process.

[0075] Example 2

[0076] Based on the same inventive concept as that of Example 1, this embodiment introduces the implementation steps of a braking energy recovery control method for a dual electric drive axle, including:

[0077] Step 1: Use the vehicle controller to obtain the braking data when the brake pedal moves in real time;

[0078] The braking data includes brake pedal opening, load and vehicle speed;

[0079] Step 2: Utilize the front and rear axle braking force distribution system to calculate the required total braking force according to the braking data, and distribute braking force coefficients to the front axle and the rear axle to obtain the front axle braking force and the rear axle braking force.

[0080] In this embodiment, the rear axle includes a first electric drive axle and a second electric drive axle.

[0081] In this embodiment, after calculating the required total braking force, the braking deceleration of the vehicle is calculated according to the required braking force, and the braking mode of the vehicle is divided into slow braking, moderate braking and emergency braking. The braking mode of the vehicle is expressed as:

[0082] ;

[0083] In the formula, Indicates the braking mode of the vehicle. "0" indicates that the braking mode of the vehicle is slow braking, "1" indicates that the braking mode of the vehicle is moderate braking, and "2" indicates that the braking mode of the vehicle is emergency braking. It is the ratio of the vehicle's braking deceleration to the acceleration due to gravity, indicating the braking intensity.

[0084] In some embodiments, when the braking mode of the vehicle is slow braking, the front axle braking force is 0, and the rear axle braking force acts on the whole vehicle braking force;

[0085] Wherein, the whole vehicle braking force is expressed as:

[0086] ;

[0087] In the formula, Indicates the vehicle braking force, Indicates the rear axle braking force;

[0088] In some embodiments, when the braking mode of the vehicle is medium braking, the front axle braking force and the rear axle braking force act together on the entire vehicle braking force;

[0089] Wherein, the whole vehicle braking force is expressed as:

[0090] ;

[0091] In the formula, Indicates the front axle braking force;

[0092] In some embodiments, when the braking mode of the vehicle is emergency braking, the front axle braking force and the rear axle braking force act together on the entire vehicle braking force;

[0093] Wherein, the whole vehicle braking force is expressed as:

[0094] .

[0095] Step 3: Based on the distribution coefficient, the rear axle braking force is distributed into mechanical braking force and regenerative braking force using the rear wheel brake distribution module.

[0096] In some embodiments, the front and rear axle braking force distribution system is used to calculate the required total braking force according to the braking data, and the braking force coefficients are distributed to the front axle and the rear axle to obtain the front axle braking force and the rear axle braking force, and the distribution coefficient is expressed as:

[0097] ;

[0098] In the formula, represents the distribution coefficient, represents the braking force coefficient, represents the correction factor, Indicates the front axle braking force, Indicates the rear axle braking force.

[0099] Step 4: Switch the motor controller 1 and the motor controller 2 to the power generation mode, convert the regenerative braking force into direct current through the power converter, charge the power battery and collect the regenerative braking force of the motor.

[0100] In some embodiments, before converting the regenerative braking force into direct current through the power converter, the vehicle controller performs a pre-check, including:

[0101] Confirm that the vehicle has entered a high-pressure state, the current gear, the initial value of the brake pedal opening, the motor speed is working normally, the battery power SOC initial value, and the anti-lock function of the brake execution system has been activated.

[0102] Step 5: Distribute the front axle braking force, mechanical braking force and motor regenerative braking force to the brake execution system.

[0103] In some embodiments, when the vehicle's braking mode is slow braking, if the entire vehicle enters the upper high-pressure state, the current gear is the forward gear, the brake pedal opening is less than 30%, the motor speed is working normally, and the battery power SOC is less than 95%, the braking execution system enters the motor braking energy recovery mode and requests to collect the motor's recovery braking force.

[0104] In this embodiment, the rear axle mechanical braking force and the recovery braking force of the motor act together on the rear axle braking force. The recovery braking force of the motor includes the recovery braking force of the first electric drive axle and the recovery braking force of the second electric drive axle. The rear axle braking force is expressed as:

[0105] ;

[0106] In the formula, Represents the rear axle braking force, Represents the rear axle mechanism power, Indicates the regenerative braking force of the first electric drive axle, Indicates the regenerative braking force of the second electric drive axle.

[0107] In some embodiments, when the braking mode of the vehicle is medium braking, if the vehicle enters the upper high pressure state, the current gear is the forward gear, the brake pedal opening is 30%-80%, the motor speed is working normally, and the battery power SOC is less than 95%, the brake execution system enters the motor braking energy recovery mode and requests to collect the motor's recovery braking force;

[0108] In this embodiment, the rear axle mechanical braking force and the recovery braking force of the motor act together on the rear axle braking force. The recovery braking force of the motor includes the recovery braking force of the first electric drive axle and the recovery braking force of the second electric drive axle. The rear axle braking force is expressed as:

[0109] ;

[0110] In the formula, Represents the rear axle braking force, Represents the rear axle mechanism power, Indicates the regenerative braking force of the first electric drive axle, Indicates the regenerative braking force of the second electric drive axle.

[0111] In some embodiments, converting the rear axle braking force into torque for control includes:

[0112] setting the brake motor torque requested by the brake actuation system to be less than the maximum available brake torque of the motor;

[0113] The brake execution system collects wheel speed signals in real time to determine whether the vehicle's anti-lock brake execution system ABS is activated:

[0114] If ABS is activated, the brake execution system exits the motor brake energy recovery mode;

[0115] If ABS is not activated, the brake execution system continues to execute the motor braking energy recovery mode and uses the vehicle controller to calculate the recovery torque allowed by the power battery.

[0116] In this embodiment, when the braking mode of the vehicle is slow braking, the maximum available braking torque through the first electric drive axle and the second electric drive axle is expressed as:

[0117] ;

[0118] In the formula, represents the maximum available braking torque through the first electric drive axle and the second electric drive axle, represents the maximum available braking torque through the first electric drive axle, Represents the maximum available braking torque through the second electric drive axle.

[0119] In this embodiment, the maximum available braking torque through the first electric drive axle is expressed as:

[0120] ;

[0121] In the formula, Indicates the maximum power of the first electric drive axle, represents the transfer efficiency, Indicates the motor speed.

[0122] In this embodiment, the maximum available braking torque through the second electric drive axle is expressed as:

[0123] ;

[0124] In the formula, Indicates the maximum power of the second electric drive axle.

[0125] In this embodiment, the request torque of the motor recovery braking force is determined by the rear wheel braking force distribution module, and the request torque of the motor recovery braking force is expressed as:

[0126] ;

[0127] In the formula, Indicates the requested torque of the motor's regenerative braking force, represents the calculation request torque, represents the total braking force required, represents the distribution coefficient, Indicates the tire radius.

[0128] In this embodiment, the power that the battery is allowed to recover is determined by the power battery UI curve, wherein the maximum allowable torque that the battery is allowed to recover is expressed as:

[0129] ;

[0130] In the formula, Indicates the power that the battery allows to be recovered. Indicates the maximum power that the battery is allowed to recover.

[0131] like Figure 2 The braking energy recovery curve shown in the figure shows that when the driver presses the pedal and is judged to be braking slowly, the front and rear axle braking force distribution module distributes the front axle braking force. The braking intensity requirement of the vehicle is relatively small, and the required torque of the motor to recover the braking force is ,in, It represents the minimum value function. The front and rear axle distribution modules detect the wheel speed changes in real time. When the vehicle is locked, the motor braking energy recovery mode is exited and the traditional air brake is performed to ensure driving safety. Among them, the recovery braking force torque of the first electric drive axle and the recovery braking force torque of the second electric drive axle are expressed as:

[0132] ;

[0133] ;

[0134] In the formula, represents the regenerative braking torque of the first electric drive axle, Indicates the regenerative braking torque of the second electric drive axle.

[0135] like Figure 2 The braking energy recovery curve shown in the figure shows that when the driver presses the pedal and is judged as moderate braking, the front and rear axle braking force distribution module distributes the front axle braking force. The braking intensity requirement of the vehicle is relatively small, and the required torque of the motor to recover the braking force is The front and rear axle distribution modules detect wheel speed changes in real time. When the vehicle is locked, the motor braking energy recovery mode is exited and traditional air braking is performed to ensure driving safety. The recovery braking torque of the first electric drive axle and the recovery braking torque of the second electric drive axle are expressed as:

[0136] ;

[0137] ;

[0138] Among them, the rear axle mechanical braking force torque is expressed as:

[0139]

[0140] In the formula, Indicates the rear axle mechanical braking force torque.

[0141] In some embodiments, when the vehicle's braking mode is emergency braking, if the entire vehicle enters the upper high-pressure state, the current gear is the forward gear, the brake pedal opening is greater than 80%, the motor speed is working normally, and the battery power SOC is less than 95%, the braking execution system exits the motor braking energy recovery mode and distributes the front axle braking force and the rear axle mechanical braking force as the rear axle braking force.

[0142] like Figure 2 The braking energy recovery curve shown in the figure shows that when the driver presses the pedal and it is judged as emergency braking, the front and rear axle braking force distribution module distributes the rear axle braking force. , front axle braking force , where the recovery braking force of the first electric drive axle is , the regenerative braking force of the second electric drive axle .

[0143] like Figure 3 As shown, in some embodiments, according to the different loads, the vehicle is adaptively adjusted to or The drive forms include:

[0144] When the load is within a preset threshold, the motor controller 1 exits the driving mode, the first electric drive axle is kept in an idling state, and the rear axle motor controller controls the rear axle motor and the rear axle gearbox to be engaged in a non-neutral gear to drive the vehicle;

[0145] When the load is not within a preset threshold, the motor controller 1 and the motor controller 2 work simultaneously to respectively control the first electric drive axle and the second electric drive axle and the transmission of the first electric drive axle and the transmission of the second electric drive axle to shift into a non-neutral gear to drive the vehicle.

[0146] In summary, the present invention obtains the braking data when the brake pedal moves, including the brake pedal opening, load and vehicle speed, through the vehicle controller, and based on the braking data, calculates and dynamically distributes the braking force coefficients of the front and rear axles through the front and rear axle braking force distribution system, thereby realizing intelligent distribution of the braking force. The present invention innovatively utilizes the rear wheel brake distribution module to subdivide the rear axle braking force into mechanical braking force and recovery braking force according to the distribution coefficient, and efficiently converts the recovery braking force into direct current and charges it into the power battery by switching the rear axle motor controller to the power generation mode, which not only improves the recovery efficiency of the braking energy, but also can flexibly adjust the ratio of the mechanical braking force and the recovery braking force according to the actual braking demand, thereby maximizing the use of the kinetic energy generated by the vehicle during the braking process while ensuring the braking safety, effectively extending the cruising range of the new energy vehicle, and improving the energy utilization efficiency of the vehicle;

[0147] The present invention calculates the braking deceleration of the vehicle in real time and divides the braking mode into three modes: slow braking, moderate braking and emergency braking. According to the braking intensity under different braking modes, the present invention can accurately distribute the braking force of the front axle and the rear axle, as well as the ratio of mechanical braking force to recovery braking force, which not only ensures the safety and stability of the braking process, but also maximizes the recovery efficiency of braking energy, effectively extending the cruising range of new energy vehicles;

[0148] Before starting the brake energy recovery function, the present invention performs a strict pre-inspection through the vehicle controller, including confirming that the vehicle has entered a high-voltage state, the current gear position, the brake pedal opening, the motor speed, the battery power SOC, and the activation state of the anti-lock function of the brake execution system, thereby effectively avoiding safety hazards caused by abnormal vehicle status and ensuring the safety and reliability of the brake energy recovery process.

[0149] The present invention can adaptively adjust the driving mode of the vehicle according to the load condition of the vehicle. When the load is light, the mid-bridge motor controller driving mode is exited and only the rear-bridge motor controller is used to drive the vehicle, so as to reduce energy consumption and improve energy recovery efficiency. When the load is heavy, the mid-bridge motor controller and the rear-bridge motor controller are used to drive the vehicle at the same time to ensure the driving performance and power output of the vehicle. The adaptive driving mode not only optimizes the energy recovery efficiency of the vehicle, but also improves the overall performance and driving experience of the vehicle.

[0150] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0151] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0152] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0153] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0154] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the protection of the present invention.

Claims

1. A braking energy recovery control method for a dual electric drive axle, characterized in that: include: Use the vehicle controller to obtain real-time braking data when the brake pedal moves; The braking data includes brake pedal opening, load and vehicle speed; Utilizing a front and rear axle braking force distribution system to calculate the required total braking force according to the braking data, and distributing braking force coefficients to the front axle and the rear axle to obtain the front axle braking force and the rear axle braking force, wherein the rear axle includes a first electric drive axle and a second electric drive axle; Based on the distribution coefficient, the rear axle braking force is distributed into mechanical braking force and regenerative braking force using the rear wheel brake distribution module; Switch the motor controller 1 and the motor controller 2 to the power generation mode, convert the regenerative braking force into direct current through the power converter, charge the power battery and collect the regenerative braking force of the motor; Distributes the front axle braking force, mechanical braking force and the electric motor's regenerative braking force to the brake actuation system.

2. The braking energy recovery control method of the dual electric drive axle according to claim 1 is characterized in that: The method further includes, after calculating the required total braking force, calculating the braking deceleration of the vehicle according to the required braking force, and dividing the braking mode of the vehicle into slow braking, moderate braking and emergency braking, wherein the braking mode of the vehicle is expressed as: ； In the formula, Indicates the braking mode of the vehicle. "0" indicates that the braking mode of the vehicle is slow braking, "1" indicates that the braking mode of the vehicle is moderate braking, and "2" indicates that the braking mode of the vehicle is emergency braking. It is the ratio of the vehicle's braking deceleration to the acceleration due to gravity, indicating the braking intensity.

3. The braking energy recovery control method of the dual electric drive axle according to claim 2 is characterized in that: When the vehicle's braking mode is slow braking, the front axle braking force is 0, and the rear axle braking force acts on the entire vehicle's braking force; Wherein, the whole vehicle braking force is expressed as: ； In the formula, Indicates the braking force of the vehicle. Indicates the rear axle braking force; When the vehicle's braking mode is medium braking, the front axle braking force and the rear axle braking force act together on the vehicle's braking force; Wherein, the whole vehicle braking force is expressed as: ； In the formula, Indicates the front axle braking force; When the vehicle's braking mode is emergency braking, the front axle braking force and the rear axle braking force act together on the vehicle's braking force; Wherein, the whole vehicle braking force is expressed as: 。 4. The braking energy recovery control method of the dual electric drive axle according to claim 1, characterized in that: The front and rear axle braking force distribution system is used to calculate the required total braking force according to the braking data, and the braking force coefficients are distributed to the front axle and the rear axle to obtain the front axle braking force and the rear axle braking force. The distribution coefficient is expressed as: ； In the formula, represents the distribution coefficient, represents the braking force coefficient, represents the correction factor, Indicates the front axle braking force, Indicates the rear axle braking force.

5. The braking energy recovery control method of the dual electric drive axle according to claim 1, characterized in that: Before converting the regenerative braking force into DC power through the power converter, the vehicle controller performs a pre-check, including: Confirm that the vehicle has entered a high-pressure state, the current gear, the initial value of the brake pedal opening, the motor speed is working normally, the battery power SOC initial value, and the anti-lock function of the brake execution system has been activated.

6. The braking energy recovery control method of the dual electric drive axle according to claim 5, characterized in that: When the vehicle's braking mode is slow braking, if the vehicle enters the upper high-pressure state, the current gear is the forward gear, the brake pedal opening is less than 30%, the motor speed is working normally, and the battery power SOC is less than 95%, the brake execution system enters the motor braking energy recovery mode and requests to collect the motor's recovery braking force; The rear axle mechanical braking force and the recovery braking force of the motor act together on the rear axle braking force. The recovery braking force of the motor includes the recovery braking force of the first electric drive axle and the recovery braking force of the second electric drive axle. The rear axle braking force is expressed as: ； In the formula, Represents the rear axle braking force, Represents the rear axle mechanism power, Indicates the regenerative braking force of the first electric drive axle, Indicates the regenerative braking force of the second electric drive axle.

7. The braking energy recovery control method of the dual electric drive axle according to claim 5, characterized in that: When the vehicle's braking mode is medium braking, if the vehicle enters the upper high-pressure state, the current gear is the forward gear, the brake pedal opening is 30%-80%, the motor speed is working normally, and the battery power SOC is less than 95%, the brake execution system enters the motor braking energy recovery mode and requests to collect the motor's recovery braking force; The rear axle mechanical braking force and the recovery braking force of the motor act together on the rear axle braking force. The recovery braking force of the motor includes the recovery braking force of the first electric drive axle and the recovery braking force of the second electric drive axle. The rear axle braking force is expressed as: ； In the formula, Represents the rear axle braking force, Represents the rear axle mechanism power, Indicates the regenerative braking force of the first electric drive axle, Indicates the regenerative braking force of the second electric drive axle.

8. The braking energy recovery control method of a dual electric drive axle according to claim 6 or 7, characterized in that: The rear axle braking force is converted into torque for control, including: setting the brake motor torque requested by the brake actuation system to be less than the maximum available brake torque of the motor; The brake execution system collects wheel speed signals in real time to determine whether the vehicle's anti-lock brake execution system ABS is activated: If ABS is activated, the brake execution system exits the motor brake energy recovery mode; If ABS is not activated, the brake execution system continues to execute the motor braking energy recovery mode and uses the vehicle controller to calculate the recovery torque allowed by the power battery.

9. The braking energy recovery control method of the dual electric drive axle according to claim 5, characterized in that: When the vehicle's braking mode is emergency braking, if the vehicle enters the upper high-pressure state, the current gear is the forward gear, the brake pedal opening is greater than 80%, the motor speed is working normally, and the battery power SOC is less than 95%, the brake execution system exits the motor braking energy recovery mode and distributes the front axle braking force and the rear axle mechanical braking force as the rear axle braking force.

10. The braking energy recovery control method of dual electric drive axles according to claim 1, characterized in that: According to the different loads, the vehicle is adaptively adjusted to or The drive forms include: When the load is within a preset threshold, the motor controller 1 exits the driving mode, the first electric drive axle is kept in an idling state, and the rear axle motor controller controls the rear axle motor and the rear axle gearbox to be engaged in a non-neutral gear to drive the vehicle; When the load is not within a preset threshold, the motor controller 1 and the motor controller 2 work simultaneously to respectively control the first electric drive axle and the second electric drive axle and the transmission of the first electric drive axle and the transmission of the second electric drive axle to shift into a non-neutral gear to drive the vehicle.

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