An electric vehicle brake friction plate running-in control method

Abstract

The application discloses a brake friction plate running-in control method for an electric vehicle, wherein a braking coordination control unit (BCCU) is embedded in an electronic and electrical architecture of the electric vehicle; the BCCU is integrated with a microprocessor and a nonvolatile memory (NVM) and is connected with other controllers or sensors of the vehicle through a controller area network (CAN) bus, a variable rate controller area network (CAN-FD) bus or an Ethernet for data interaction; and the BCCU controls the vehicle braking system to switch among three modes of hydraulic braking priority, motor braking priority and safety exemption according to vehicle driving and maintenance conditions. The brake friction plate running-in control method for the electric vehicle has the beneficial technical effect that after the vehicle is delivered from a factory or brake pads and / or brake discs are replaced, hydraulic braking is used as much as possible before the brake pads and the brake discs are completely run-in, so that the brake pads and the brake discs are run-in as soon as possible to reach the design standard, thereby ensuring that the brake performance meets the relevant requirements.

Description

Technical Field

[0001] This invention relates to a method for controlling the break-in of brake friction pads in electric vehicles, and more particularly to a method for controlling the break-in of brake friction pads in electric vehicles. Background Technology

[0002] Currently, electric vehicles generally employ an electro-hydraulic hybrid braking system, which combines electric motor braking and hydraulic braking. Electric motor braking refers to a system where, during vehicle operation, no electrical energy is input to the drive motor; instead, the vehicle continues to move using its inertia, causing the motor to generate electricity in reverse. In this state, the vehicle's kinetic energy is converted into electrical energy (energy recovery), gradually reducing the vehicle's speed and thus braking it. Hydraulic braking refers to a system where, during vehicle operation, a hydraulic system controls the brake pads to "grip" against the brake discs, gradually reducing the vehicle's speed and thus braking it. To maximize energy recovery, a "motor braking priority" control strategy is typically adopted, prioritizing electric motor braking (energy recovery) and supplementing the remaining energy with hydraulic braking.

[0003] However, brake pads and discs in a hydraulic braking system must undergo a certain number of physical friction cycles (i.e., "break-in") to ensure uniform contact between their contact surfaces and achieve the designed coefficient of friction, thereby guaranteeing braking performance. After a new car leaves the factory or after new brake pads are installed, it needs to undergo 200 km or more of actual driving and multiple break-in cycles to ensure the hydraulic braking friction coefficient reaches the design standard and guarantees braking performance. For electric vehicles that continue to use a "motor braking priority" control strategy after leaving the factory or after new brake pads are installed, the brake pads and discs will not be properly broken in for a long time. This not only easily leads to brake squealing noises but also results in longer braking distances during emergency braking due to insufficient friction caused by the unbroken brake pads, posing a significant safety hazard. Furthermore, the inability of brake pads and brake discs to complete physical break-in over a long period can easily lead to a low initial coefficient of friction, resulting in a sluggish brake pedal feel (insufficient braking force), high-frequency brake squealing due to the lack of a uniform transfer film, glass formation and sintering of the friction surface caused by localized heat concentration, and high-speed braking vibration due to uneven wear of the disc surface. This severely degrades the user's driving experience and increases the after-sales warranty claim rate.

[0004] In addition, when replacing brake pads, calipers, or brake discs in existing electric vehicles, a diagnostic device needs to send a command to the Electronic Parking Brake Controller (EPB) to enter maintenance mode. The EPB then releases the caliper and removes the part for replacement. After the part replacement is completed, the diagnostic device sends a calibration and confirmation command to the EPB. The EPB then controls the caliper to push forward until the friction pad is in contact with the brake disc and automatically calibrates. After the EPB responds and confirms successful calibration, the diagnostic device sends a command to the EPB to exit maintenance mode, and the replacement is complete. Summary of the Invention

[0005] To address the above problems, this invention proposes a method for controlling the break-in of brake friction pads in electric vehicles.

[0006] This invention discloses a method for controlling the break-in of brake friction pads in electric vehicles. A Braking Coordination Control Unit (BCCU) is embedded in the electronic and electrical architecture of the electric vehicle. The BCCU integrates a microprocessor and non-volatile memory (NVM), and interacts with other vehicle controllers or sensors via the CAN bus, CAN-FD bus, or Ethernet. The BCCU controls the vehicle's braking system to switch between three modes—hydraulic braking priority, electric motor braking priority, and safety exemption—based on vehicle driving and maintenance conditions.

[0007] The hydraulic brake priority mode refers to the mode applied to vehicles after they leave the factory or after replacing brake pads and / or brake discs, and before the mileage reaches a set threshold. At this time, the vehicle braking system adopts a hydraulic braking priority control strategy, that is, hydraulic braking is used first when braking to ensure that the brake pads and brake discs are effectively broken in; the set threshold The value is 200km and above;

[0008] The electric motor braking priority mode refers to the mode that is used after the vehicle leaves the factory or after the brake pads and / or brake discs are replaced, and the mileage reaches or exceeds a set threshold. At this time, the vehicle braking system adopts a control strategy that prioritizes electric motor braking, that is, it prioritizes the use of electric motor braking when braking, in order to ensure that as much energy is recovered as possible.

[0009] The safety exemption mode refers to the BCCU controlling the vehicle's braking system to use hydraulic braking entirely when the vehicle is in an emergency state, under hydraulic braking priority mode; the emergency state refers to the activation of any one or more of the vehicle's anti-lock braking system (ABS), anti-skid system (ESP), anti-skid system (TCS), or / and automatic emergency braking system (AEB).

[0010] Furthermore, embedding the Braking Coordination Control Unit (BCCU) in the electronic and electrical architecture of the electric vehicle includes: physically integrating the BCCU within the braking control hardware of the chassis domain, including the Electronic Brake Booster (EBB), Anti-lock Braking System (ABS / ESP), or Braking By-Wire (EMB / EHB); or physically integrating the BCCU within the cross-domain vehicle control hardware, including the Vehicle Controller (VCU) or the Chassis Domain Controller.

[0011] Furthermore, the vehicle has not reached the set threshold after leaving the factory or after replacing the brake pads and / or brake discs. The time-based judgment includes the BCCU reading the vehicle's real-time total mileage. ,when ≤ At that time, it is determined that the vehicle has left the factory and the mileage has not reached the set threshold. ;when ≤ When the vehicle has had its brake pads and / or brake discs replaced and the mileage has not reached the set threshold, it is determined that the vehicle has been in operation for a period of time. The This refers to the relative mileage of the vehicle, i.e. In the formula, This refers to the starting mileage of the hydraulic brake priority mode. When the BCCU detects the exit from maintenance mode issued by the Electronic Parking Brake Controller (EPB) and simultaneously receives a confirmation signal that the EPB position calibration was successful, confirming that the brake pads and / or brake discs have just been replaced, it reads the vehicle's real-time total mileage and writes this real-time total mileage into the BCCU's physical non-volatile memory (NVM) for storage. This serves as the starting mileage of the hydraulic brake priority mode after the replacement of the brake pads and / or brake discs. Furthermore, during subsequent daily driving, starting, or stopping operations, it is prohibited to write any accumulated mileage data to this NVM address.

[0012] Furthermore, the vehicle braking system adopts a hydraulic braking priority control strategy and uses a progressive smooth transition algorithm to control the distribution ratio of hydraulic braking force and electric motor power, including:

[0013] definition:

[0014] Motor braking limit coefficient Its value ranges from 0 to 1;

[0015] Actual allocated motor power commands The vehicle power control unit follows the instructions. Control the power of the electric motor;

[0016] Actual hydraulic braking force command The vehicle's hydraulic actuators follow the instructions. Control the hydraulic braking force;

[0017] This is the vehicle's real-time total mileage, i.e., the vehicle's real-time total mileage read by the BCCU, in km.

[0018] This refers to the relative mileage of the vehicle, which is the distance the vehicle has traveled after replacing the brake pads and / or brake discs, in km.

[0019] This is the first mileage threshold, in km; the value is 150 km and above.

[0020] This is the second mileage threshold, in km; the value is 200 km or more.

[0021] but:

[0022]

[0023]

[0024] In the formula, This represents the maximum electric motor power theoretically possible to provide under the current vehicle speed and battery conditions. The total braking force required for the driver to depress the pedal;

[0025] when or ≤ This is a forced break-in period. , The value ranges from 0.1 to 0.8, preferably from 0.3 to 0.6;

[0026] when ≤ or ≤ At that time, in order to consolidate the break-in period,

[0027] ;in, ;

[0028] when or > hour, The motor braking is unrestricted, and the break-in period is over.

[0029] Furthermore, the break-in control method for brake friction pads in electric vehicles of the present invention includes the following steps:

[0030] S1. When the vehicle is powered on, the Braking Coordination Control Unit (BCCU) performs software initialization and establishes data interaction with other controllers or sensors in the vehicle. The BCCU is embedded in the electronic and electrical architecture of the electric vehicle and integrates a microprocessor and non-volatile memory (NVM). It interacts with other controllers or sensors in the vehicle via the CAN bus, CAN-FD bus, or Ethernet.

[0031] S2, BCCU reads the current total mileage of the vehicle. ;

[0032] S3, BCCU judgment ≤ If yes, proceed to step S5; otherwise, proceed sequentially to step S4. The threshold value is set to 200km and above;

[0033] S4, BCCU judgment ≤ If yes, proceed to step S5 sequentially; otherwise, proceed to step S6. This refers to the relative mileage traveled by the vehicle. In the formula, The starting mileage for hydraulic brake priority mode is determined by the BCCU detecting the exit from maintenance mode from the Electronic Parking Brake Controller (EPB) and simultaneously receiving a confirmation signal of successful EPB position calibration. This confirms that the brake pads and / or brake discs have just been replaced. The BCCU then reads the vehicle's real-time total mileage and saves it to the BCCU's physical non-volatile memory (NVM). This serves as the starting mileage for hydraulic brake priority mode after the replacement of the brake pads and / or brake discs. Furthermore, during subsequent daily driving, starting, or stopping operations, it is prohibited to write any accumulated mileage data to this NVM address.

[0034] S5. Enter hydraulic brake priority mode, that is, the vehicle braking system adopts the hydraulic brake priority control strategy, and hydraulic braking is used first when braking to ensure that the brake pads and brake discs are effectively broken in.

[0035] S501, when or ≤ At this time, the BCCU control enters a forced break-in period, that is:

[0036] , The value ranges from 0.1 to 0.8, preferably from 0.3 to 0.6; where, This is the first mileage threshold, in km; the value is 150 km and above. This is the motor braking limit coefficient, and its value ranges from 0 to 1; and,

[0037] ;

[0038]

[0039] In the formula, This represents the maximum electric motor power theoretically possible to provide under the current vehicle speed and battery conditions. The total braking force required for the driver to depress the pedal; The vehicle power control unit executes the actual assigned electric motor power commands. Control the power of the electric motor; The vehicle's hydraulic actuators respond to the actual hydraulic braking force command. Control the hydraulic braking force;

[0040] S502, when ≤ or ≤ At this time, the BCCU control enters the consolidation and break-in period, that is:

[0041] ;in, ; This is the second mileage threshold, in km; the value is 200 km or more.

[0042] S503, when or > hour, The motor braking is unrestricted, and the break-in period is over;

[0043] In addition, during the entire S5 process, the BCCU continuously monitors whether the vehicle is in an emergency state. Once an emergency state occurs, the BCCU controls the vehicle's braking system to enter a safety exemption mode, which means that the hydraulic braking is used entirely. The emergency state refers to the activation of any one or more of the vehicle's anti-lock braking system (ABS), anti-skid system (ESP), anti-skid system (TCS), and / or automatic emergency braking system (AEB).

[0044] S6. Enter motor braking priority mode and operate normally.

[0045] Furthermore, the BCCU integrates a maintenance module with diagnostic equipment functions. This maintenance module can send commands to the Electronic Parking Brake (EPB) system to enter maintenance mode; after the parts are replaced, it sends calibration and confirmation commands to confirm the calibration is complete; after the EPB responds and confirms the calibration is successful, it sends a command to the EPB to exit maintenance mode. At this time, the BCCU can automatically confirm that the brake pads and / or brake discs have just been replaced without relying on the relevant information from the EPB.

[0046] The beneficial technical effect of the electric vehicle brake friction pad break-in control method of the present invention is that after the vehicle leaves the factory or after the brake pads and / or brake discs are replaced, before the brake pads and brake discs are fully broken in, hydraulic braking is used as much as possible to allow them to break in as quickly as possible to reach the design standards, thereby ensuring that the braking performance meets the relevant requirements. Attached Figure Description

[0047] Appendix Figure 1 This is a schematic diagram illustrating the system principle and architecture of the electric vehicle brake friction pad break-in control method of the present invention;

[0048] Appendix Figure 2 This is a flowchart of the electric vehicle brake friction pad break-in control method of the present invention.

[0049] The running-in control method for brake friction pads of electric vehicles of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. Detailed Implementation

[0050] This invention discloses a method for controlling the break-in of brake friction pads in electric vehicles. A Braking Coordination Control Unit (BCCU) is embedded in the electronic and electrical architecture of the electric vehicle. The BCCU integrates a microprocessor and non-volatile memory (NVM), and interacts with other vehicle controllers or sensors via the CAN bus, CAN-FD bus, or Ethernet. The BCCU controls the vehicle's braking system to switch between three modes—hydraulic braking priority, electric motor braking priority, and safety exemption—based on vehicle driving and maintenance conditions.

[0051] The hydraulic brake priority mode refers to the mode applied to vehicles after they leave the factory or after replacing brake pads and / or brake discs, and before the mileage reaches a set threshold. At this time, the vehicle braking system adopts a hydraulic braking priority control strategy, that is, hydraulic braking is used first when braking to ensure that the brake pads and brake discs are effectively broken in; the set threshold The value is 200km and above;

[0052] The electric motor braking priority mode refers to the mode that is used after the vehicle leaves the factory or after the brake pads and / or brake discs are replaced, and the mileage reaches or exceeds a set threshold. At this time, the vehicle braking system adopts a control strategy that prioritizes electric motor braking, that is, it prioritizes the use of electric motor braking when braking, in order to ensure that as much energy is recovered as possible.

[0053] The safety exemption mode refers to the BCCU controlling the vehicle's braking system to use hydraulic braking entirely when the vehicle is in an emergency state, under hydraulic braking priority mode; the emergency state refers to the activation of any one or more of the vehicle's anti-lock braking system (ABS), anti-skid system (ESP), anti-skid system (TCS), or / and automatic emergency braking system (AEB).

[0054] See appendix Figure 1 This invention provides a method for controlling the break-in of brake pads in electric vehicles. It divides vehicle braking into three modes: hydraulic braking priority, electric motor braking priority, and safety exemption. The system switches between these modes based on vehicle driving and maintenance conditions. When a vehicle leaves the factory or after replacing brake pads and / or brake discs, and the mileage has not reached a set threshold, the hydraulic braking priority mode is used. This allows the brake pads and discs to break in quickly, bringing their friction coefficient to the design standard as soon as possible. This avoids squealing noises during braking and ensures that the braking distance is not increased due to insufficient friction or incomplete brake pad break-in during emergency braking, eliminating significant safety hazards. Furthermore, to prevent accidents during the break-in period, this invention also includes a safety exemption mode. During the break-in period, the BCCU monitors the vehicle's dynamics in real time. Once the safety exemption condition is triggered, the system instantly (response time ≤ 50 ms) unconditionally interrupts the current break-in control strategy, controlling the vehicle braking system to use hydraulic braking exclusively to ensure vehicle driving and braking safety.

[0055] As one of the preferred technical solutions, embedding the Brake Coordination Control Unit (BCCU) in the electronic and electrical architecture of the electric vehicle includes: physically integrating the BCCU within the chassis domain braking control hardware, including the Electronic Brake Booster (EBB), Anti-lock Braking System (ABS / ESP), or Brake-by-Wire (EMB / EHB); or physically integrating the BCCU within cross-domain vehicle control hardware, including the Vehicle Control Unit (VCU) or the Chassis Domain Controller (Chassis Domain Controller). Physically integrating the BCCU within the chassis domain braking control hardware or across-domain vehicle control hardware not only facilitates data interaction between the BCCU and other vehicle controllers or sensors but also fully utilizes the vehicle's existing hardware and software infrastructure.

[0056] As one of the preferred technical solutions, the vehicle has been manufactured or the brake pads and / or brake discs have been replaced, and the mileage has not reached the set threshold. The time-based judgment includes the BCCU reading the vehicle's real-time total mileage. ,when ≤ At that time, it is determined that the vehicle has left the factory and the mileage has not reached the set threshold. ;when ≤ When the vehicle has had its brake pads and / or brake discs replaced and the mileage has not reached the set threshold, it is determined that the vehicle has been in operation for a period of time. The This refers to the relative mileage of the vehicle, i.e. In the formula, This refers to the starting mileage of the hydraulic brake priority mode. When the BCCU detects the exit from maintenance mode issued by the Electronic Parking Brake Controller (EPB) and simultaneously receives a confirmation signal that the EPB position calibration was successful, confirming that the brake pads and / or brake discs have just been replaced, it reads the vehicle's real-time total mileage and writes this real-time total mileage into the BCCU's physical non-volatile memory (NVM) for storage. This serves as the starting mileage of the hydraulic brake priority mode after the replacement of the brake pads and / or brake discs. Furthermore, during subsequent daily driving, starting, or shutdown conditions, it is prohibited to write any accumulated mileage data to this NVM address. The BCCU of the electric vehicle brake pad break-in control method of this invention can monitor various commands issued by the electronic parking brake controller (EPB), and uses the EPB's command to exit maintenance mode and the confirmation signal of successful position calibration as the basis for determining that the brake pads and / or brake discs have just been replaced. The real-time total mileage of the vehicle read at this moment is used as the starting point of a new break-in cycle for the brake pads and brake discs. The entire process requires no manual operation or intervention, achieving full automation. The non-volatile memory (NVM) is used to store the starting value of the new break-in cycle. This can prevent the starting value of the new break-in period from being lost in the event of an unexpected power outage, operational errors, or other situations. Accidental erasure can lead to inaccurate calculation of the break-in period.

[0057] As one of the preferred technical solutions, the vehicle braking system adopts a hydraulic braking priority control strategy and uses a progressive smooth transition algorithm to control the distribution ratio of hydraulic braking force and electric motor power, including:

[0058] definition:

[0059] Motor braking limit coefficient Its value ranges from 0 to 1;

[0060] Actual allocated motor power commands The vehicle power control unit follows the instructions. Control the power of the electric motor;

[0061] Actual hydraulic braking force command The vehicle's hydraulic actuators follow the instructions. Control the hydraulic braking force;

[0062] This is the vehicle's real-time total mileage, i.e., the vehicle's real-time total mileage read by the BCCU, in km.

[0063] This refers to the relative mileage of the vehicle, which is the distance the vehicle has traveled after replacing the brake pads and / or brake discs, in km.

[0064] This is the first mileage threshold, in km; the value is 150 km and above.

[0065] This is the second mileage threshold, in km; the value is 200 km or more.

[0066] but:

[0067]

[0068]

[0069] In the formula, This represents the maximum electric motor power theoretically possible to provide under the current vehicle speed and battery conditions. The total braking force required for the driver to depress the pedal;

[0070] when or ≤ This is a forced break-in period. , The value ranges from 0.1 to 0.8, preferably from 0.3 to 0.6;

[0071] when ≤ or ≤ At that time, in order to consolidate the break-in period,

[0072] ;in, ;

[0073] when or > hour, The motor braking is unrestricted, and the break-in period is over.

[0074] A progressive, smooth transition algorithm is used to control the distribution ratio of hydraulic and electric braking forces. This allows for dynamic adjustment of the ratio while ensuring vehicle deceleration requirements are met, thus preventing abrupt changes in driver pedal feel (discontinuous deceleration) due to limited electric braking. Typically, newly replaced brake pads or discs have manufacturing residues and uneven macroscopic contact surfaces, requiring a "break-in" process through high-frequency physical friction. Therefore, forced break-in is necessary in the initial stage, using hydraulic braking as much as possible or controlling the proportion of hydraulic braking force. After a period of break-in, the manufacturing residues on the brake pads or discs are eliminated, and the uneven macroscopic contact surface is improved, allowing for consolidation break-in, which involves appropriately increasing the proportion of electronic braking force. Once the brake pads or discs are fully broken in and the friction coefficient has met design requirements, the electric braking priority mode can be used for normal operation.

[0075] See appendix Figure 2 As one of the preferred technical solutions, the electric vehicle brake friction pad break-in control method of the present invention includes the following steps:

[0076] S1. When the vehicle is powered on, the Braking Coordination Control Unit (BCCU) performs software initialization and establishes data interaction with other controllers or sensors in the vehicle. The BCCU is embedded in the electronic and electrical architecture of the electric vehicle and integrates a microprocessor and non-volatile memory (NVM). It interacts with other controllers or sensors in the vehicle via the CAN bus, CAN-FD bus, or Ethernet.

[0077] S2, BCCU reads the current total mileage of the vehicle. ;

[0078] S3, BCCU judgment ≤ If yes, proceed to step S5; otherwise, proceed sequentially to step S4. The threshold value is set to 200km and above;

[0079] S4, BCCU judgment ≤ If yes, proceed to step S5 sequentially; otherwise, proceed to step S6. This refers to the relative mileage traveled by the vehicle. In the formula, The starting mileage for hydraulic brake priority mode is determined by the BCCU detecting the exit from maintenance mode from the Electronic Parking Brake Controller (EPB) and simultaneously receiving a confirmation signal of successful EPB position calibration. This confirms that the brake pads and / or brake discs have just been replaced. The BCCU then reads the vehicle's real-time total mileage and saves it to the BCCU's physical non-volatile memory (NVM). This serves as the starting mileage for hydraulic brake priority mode after the replacement of the brake pads and / or brake discs. Furthermore, during subsequent daily driving, starting, or stopping operations, it is prohibited to write any accumulated mileage data to this NVM address.

[0080] S5. Enter hydraulic brake priority mode, that is, the vehicle braking system adopts the hydraulic brake priority control strategy, and hydraulic braking is used first when braking to ensure that the brake pads and brake discs are effectively broken in.

[0081] S501, when or ≤ At this time, the BCCU control enters a forced break-in period, that is:

[0082] , The value ranges from 0.1 to 0.8, preferably from 0.3 to 0.6; where, This is the first mileage threshold, in km; the value is 150 km and above. This is the motor braking limit coefficient, and its value ranges from 0 to 1; and,

[0083] ;

[0084]

[0085] In the formula, This represents the maximum electric motor power theoretically possible to provide under the current vehicle speed and battery conditions. The total braking force required for the driver to depress the pedal; The vehicle power control unit executes the actual assigned electric motor power commands. Control the power of the electric motor; The vehicle's hydraulic actuators respond to the actual hydraulic braking force command. Control the hydraulic braking force;

[0086] S502, when ≤ or ≤ At this time, the BCCU control enters the consolidation and break-in period, that is:

[0087] ;in, ; This is the second mileage threshold, in km; the value is 200 km or more.

[0088] S503, when or > hour, The motor braking is unrestricted, and the break-in period is over;

[0089] In addition, during the entire S5 process, the BCCU continuously monitors whether the vehicle is in an emergency state. Once an emergency state occurs, the BCCU controls the vehicle's braking system to enter a safety exemption mode, which means that the hydraulic braking is used entirely. The emergency state refers to the activation of any one or more of the vehicle's anti-lock braking system (ABS), anti-skid system (ESP), anti-skid system (TCS), and / or automatic emergency braking system (AEB).

[0090] S6. Enter motor braking priority mode and operate normally.

[0091] As a preferred technical solution, the BCCU integrates a maintenance module with diagnostic equipment functions. This module can send commands to the Electronic Parking Brake (EPB) system to enter maintenance mode; after parts replacement is completed, it sends calibration and confirmation commands to confirm calibration completion; after the EPB confirms successful calibration, it sends a command to exit maintenance mode. At this point, the BCCU can automatically confirm that the brake pads and / or brake discs have just been replaced without relying on EPB information. Integrating a maintenance module with diagnostic equipment functions into the BCCU not only facilitates the repair or replacement of brake pads, calipers, or brake discs, but also enables quick, accurate, and effective acquisition of brake pad or brake disc replacement information.

[0092] Obviously, the beneficial technical effect of the electric vehicle brake friction pad break-in control method of the present invention is that after the vehicle leaves the factory or after the brake pads and / or brake discs are replaced, before the vehicle brake pads and brake discs are fully broken in, hydraulic braking is used as much as possible to make them break in to the design standards as soon as possible, thereby ensuring that the braking performance meets the relevant requirements.

Claims

1. A method for controlling the break-in of brake friction pads in electric vehicles, characterized in that, A Braking Coordination Control Unit (BCCU) is embedded in the electronic and electrical architecture of an electric vehicle. The BCCU integrates a microprocessor and non-volatile memory (NVM), and interacts with other vehicle controllers or sensors via the CAN bus, CAN-FD bus, or Ethernet. The BCCU controls the vehicle's braking system to switch between three modes—hydraulic braking priority, electric motor braking priority, and safety exemption—based on vehicle driving and maintenance conditions. The hydraulic brake priority mode refers to the mode applied to vehicles after they leave the factory or after replacing brake pads and / or brake discs, and before the mileage reaches a set threshold. At this time, the vehicle braking system adopts a hydraulic braking priority control strategy, that is, hydraulic braking is used first when braking to ensure that the brake pads and brake discs are effectively broken in; the set threshold The value is 200km and above; The electric motor braking priority mode refers to the mode applied to vehicles after they leave the factory or after replacing brake pads and / or brake discs, and when the mileage reaches or exceeds a set threshold. At this time, the vehicle braking system adopts a control strategy that prioritizes electric motor braking, that is, when braking, electric motor braking is used first to ensure that as much energy is recovered as possible. The safety exemption mode refers to the BCCU controlling the vehicle's braking system to use hydraulic braking entirely when the vehicle is in an emergency state, under hydraulic braking priority mode; the emergency state refers to the activation of any one or more of the vehicle's anti-lock braking system (ABS), anti-skid system (ESP), anti-skid system (TCS), or / and automatic emergency braking system (AEB).

2. The method for controlling the break-in of brake friction pads in electric vehicles according to claim 1, characterized in that, The embedding of a Brake Coordination Control Unit (BCCU) in the electronic and electrical architecture of an electric vehicle includes: physically integrating the BCCU within the chassis-domain brake control hardware, including an Electronic Brake Booster (EBB), an Anti-lock Braking System (ABS / ESP), or a Brake-by-Wire (EMB / EHB); or physically integrating the BCCU within cross-domain vehicle control hardware. This includes the vehicle control unit (VCU) or the chassis domain controller.

3. The method for controlling the break-in of brake friction pads in electric vehicles according to claim 1, characterized in that, The vehicle has been manufactured or its brake pads and / or brake discs have been replaced, and its mileage has not reached the set threshold. The time-based judgment includes the BCCU reading the vehicle's real-time total mileage. ,when ≤ At that time, it is determined that the vehicle has left the factory and the mileage has not reached the set threshold. ;when ≤ When the vehicle has had its brake pads and / or brake discs replaced and the mileage has not reached the set threshold, it is determined that the vehicle has been in operation for a period of time. The This refers to the relative mileage of the vehicle, i.e. In the formula, This refers to the starting mileage of the hydraulic brake priority mode. When the BCCU detects the exit from maintenance mode issued by the Electronic Parking Brake Controller (EPB) and simultaneously receives a confirmation signal of successful EPB position calibration, confirming that the brake pads and / or brake discs have just been replaced, it reads the vehicle's real-time total mileage and writes this real-time total mileage into the BCCU's physical non-volatile memory (NVM) for storage. This serves as the starting mileage of the hydraulic brake priority mode after the replacement of the brake pads and / or brake discs. ; Furthermore, during subsequent daily driving, starting, or stopping operations, it is prohibited to write any accumulated mileage data to this NVM address.

4. The method for controlling the break-in of brake friction pads in electric vehicles according to claim 1, characterized in that, The vehicle braking system adopts a hydraulic braking priority control strategy and uses a progressive smooth transition algorithm to control the distribution ratio of hydraulic braking force and electric motor power, including: definition: Motor braking limit coefficient Its value ranges from 0 to 1; Actual allocated motor power command The vehicle power control unit follows the instructions. Control the power of the electric motor; Actual hydraulic braking force command The vehicle's hydraulic actuators follow the instructions. Control the hydraulic braking force; This is the vehicle's real-time total mileage, which is the total real-time mileage of the vehicle read by the BCCU, in km. This refers to the relative mileage of the vehicle, which is the distance the vehicle has traveled after replacing the brake pads and / or brake discs, in km. This is the first mileage threshold, in km; the value is 150 km and above. This is the second mileage threshold, in km; the value is 200 km or more. but: In the formula, This represents the maximum electric motor power theoretically possible to provide under the current vehicle speed and battery conditions. The total braking force required for the driver to depress the pedal; when or ≤ This is a forced break-in period. , The value ranges from 0.1 to 0.8, preferably from 0.3 to 0.6; when ≤ or ≤ At that time, in order to consolidate the break-in period, ;in, ; when or > hour, The motor braking is unrestricted, and the break-in period is over.

5. The method for controlling the break-in of brake friction pads in electric vehicles according to claim 1, characterized in that, The BCCU integrates a maintenance module with diagnostic equipment functions. This maintenance module can send commands to the Electronic Parking Brake (EPB) system to enter maintenance mode; after the parts are replaced, it sends calibration and confirmation commands to confirm the calibration is complete; after the EPB responds and confirms the calibration is successful, it sends a command to the EPB to exit maintenance mode; at this time, the BCCU can automatically confirm that the brake pads and / or brake discs have just been replaced without relying on the relevant information from the EPB.

6. The method for controlling the break-in of brake friction pads for electric vehicles according to any one of claims 1 to 5, characterized in that, The present invention provides a method for controlling the break-in of brake friction pads in electric vehicles, comprising the following steps: S1. When the vehicle is powered on, the Braking Coordination Control Unit (BCCU) performs software initialization and establishes data interaction with other controllers or sensors in the vehicle. The BCCU is embedded in the electronic and electrical architecture of the electric vehicle and integrates a microprocessor and non-volatile memory (NVM). It interacts with other controllers or sensors in the vehicle via the CAN bus, CAN-FD bus, or Ethernet. S2, BCCU reads the current total mileage of the vehicle. ; S3, BCCU judgment ≤ If yes, proceed to step S5; otherwise, proceed sequentially to step S4. The threshold value is set to 200km and above; S4, BCCU judgment ≤ If yes, proceed to step S5 sequentially; otherwise, proceed to step S6. This refers to the relative mileage traveled by the vehicle. In the formula, The starting mileage for hydraulic brake priority mode is determined by the BCCU detecting the exit from maintenance mode from the Electronic Parking Brake Controller (EPB) and simultaneously receiving a confirmation signal of successful EPB position calibration. This confirms that the brake pads and / or brake discs have just been replaced. The BCCU then reads the vehicle's real-time total mileage and saves it to the BCCU's physical non-volatile memory (NVM). This serves as the starting mileage for hydraulic brake priority mode after the replacement of the brake pads and / or brake discs. Furthermore, during subsequent daily driving, starting, or stopping operations, it is prohibited to write any accumulated mileage data to this NVM address. S5. Enter hydraulic brake priority mode, that is, the vehicle braking system adopts the hydraulic brake priority control strategy, and hydraulic braking is used first when braking to ensure that the brake pads and brake discs are effectively broken in. S501, when or ≤ At this time, the BCCU control enters a forced break-in period, that is: , The value ranges from 0.1 to 0.8, preferably from 0.3 to 0.6; where, This is the first mileage threshold, in km; the value is 150 km and above. This is the motor braking limit coefficient, and its value ranges from 0 to 1; and, ； In the formula, This represents the maximum electric motor power theoretically possible to provide under the current vehicle speed and battery conditions. The total braking force required for the driver to depress the pedal; The vehicle power control unit executes the actual assigned electric motor power commands. Control the power of the electric motor; The vehicle's hydraulic actuators respond to the actual hydraulic braking force command. Control the hydraulic braking force; S502, when ≤ or ≤ At this time, the BCCU control enters the consolidation and break-in period, that is: ;in, ; This is the second mileage threshold, in km; the value is 200 km or more. S503, when or > hour, The motor braking is unrestricted, and the break-in period is over; In addition, during the entire S5 process, the BCCU continuously monitors whether the vehicle is in an emergency state. Once an emergency state occurs, the BCCU controls the vehicle's braking system to enter a safety exemption mode, which means that the hydraulic braking is used entirely. The emergency state refers to the activation of any one or more of the vehicle's anti-lock braking system (ABS), anti-skid system (ESP), anti-skid system (TCS), and / or automatic emergency braking system (AEB). S6. Enter motor braking priority mode and operate normally.

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