A dual-redundant electronic brake booster system and control method

Abstract

A dual-redundant electronic brake booster system includes a pedal module U1 and a booster module U2. The pedal module U1 includes a linkage pedal, a first analog master cylinder, and a second analog master cylinder. The linkage pedal is connected to the first analog master cylinder and the second analog master cylinder through two pipelines. A first pedal feel sensor is provided on the pipeline between the first analog master cylinder and the linkage pedal, and a second pedal feel sensor is provided on the pipeline between the second analog master cylinder and the linkage pedal. When the driver applies a pedal force to the linkage pedal, the linkage pedal pushes the two analog master cylinders to simultaneously establish hydraulic pressure, and the first pedal feel sensor and the second pedal feel sensor send the pedal stroke signal to the ECU controller. The booster module U2 is connected to U1 through a pipeline. The booster module U2 is externally connected to the ESC, and the ESC is connected to the brake. A dual-loop independent design is adopted to achieve mutual redundancy and have multi-level backup capabilities, greatly improving the system safety performance.

Description

Technical Field

[0001] The present invention belongs to the field of vehicle brake booster system control, and particularly relates to a dual-redundancy electronic brake booster system and a control method. Background Art

[0002] With the development of automotive electrification and intelligence, electronic boosters have become a common solution for vehicles to achieve wire control braking. However, the existing electronic boosters with mature structures are mostly used in light vehicles below 5 tons such as M1 and N1. For vehicles of N2 and M3 types exceeding 5 tons, as the vehicle weight increases, the load on the vehicle braking system also increases accordingly. The existing electronic booster structures cannot meet the braking assistance requirements of the vehicle, nor can they meet the safety mandatory regulations such as emergency braking and braking redundancy in GB 12676-2014. To solve these problems, it is necessary to expand and innovate on the basis of the existing electronic booster structure. Summary of the Invention

[0003] The problem to be solved by the present invention is that for vehicles of N2 and M3 types exceeding 5 tons, the existing electronic booster structures cannot meet the braking assistance requirements of the vehicle, nor can they meet the safety mandatory regulations such as emergency braking and braking redundancy in GB 12676-2014.

[0004] The technical solution adopted by the present invention is: a dual-redundancy electronic brake booster system, including a pedal module U1 and a booster module U2. The pedal module U1 includes a linkage pedal, a first analog master cylinder, and a second analog master cylinder';

[0005] The linkage pedal is connected to the first analog master cylinder and the second analog master cylinder' through two pipelines. A first pedal feel sensor is arranged on the pipeline between the first analog master cylinder and the linkage pedal, and a second pedal feel sensor' is arranged on the pipeline between the second analog master cylinder' and the linkage pedal. When the driver applies a pedal force to the linkage pedal, the linkage pedal pushes the two analog master cylinders to establish hydraulic pressure simultaneously. The first pedal feel sensor and the second pedal feel sensor' send the pedal travel signal to the ECU controller;

[0006] The booster module U2 is connected to U1 through a pipeline. The booster module U2 is externally connected to the ESC, and the ESC is connected to the brake.

[0007] Further, the booster module U2 includes a first pipeline L1, a second pipeline L2, a third pipeline L3, a fourth pipeline L4, a fifth pipeline L5, a sixth pipeline L6, a seventh pipeline L7, an eighth pipeline L8, a ninth pipeline L9, a tenth pipeline L10, and a brake oil pot 4. One ends of the first pipeline L1 and the second pipeline L2 are respectively connected to the first analog master cylinder and the second analog master cylinder', and the other ends are both connected to the vehicle ESC. The ESC is connected to the brake;

[0008] The third pipeline L3 is connected to the first pipeline L1. An first assist valve A1, a first pressure sensor S1, a first assist master cylinder, a first motor and a first motor current sensor are sequentially arranged on the third pipeline L3. A first motor position sensor is arranged on the first motor; The fourth pipeline L4 is connected to the second pipeline L2. A second assist valve A2, a second pressure sensor S2, a second assist master cylinder', a second motor' and a second motor current sensor' are sequentially arranged on the fourth pipeline L4. A second motor position sensor' is arranged on the second motor'; The first assist master cylinder is connected to the brake oil pot through the seventh pipeline L, and a first one-way valve is arranged on the seventh pipeline L; The second assist master cylinder' is connected to the brake oil pot through the eighth pipeline L8, and a second one-way valve is arranged on the eighth pipeline L8;

[0009] One end of the fifth pipeline L5 is connected to the first pipeline L1, and the other end is connected to the brake oil pot (4). A first pedal decoupling valve D1 and a first pedal feel simulation load are arranged on the fifth pipeline L5; One end of the sixth pipeline L6 is connected to the second pipeline L2, and the other end is connected to the brake oil pot. A second pedal decoupling valve D2 and a second pedal feel simulation load are arranged on the sixth pipeline L6;

[0010] The first simulation master cylinder is connected to the brake oil pot through the ninth pipeline L9, and a first exhaust valve C1 is arranged on the ninth pipeline L9; The second simulation master cylinder is connected to the second simulation master cylinder through the tenth pipeline L10; A second exhaust valve C2 is arranged on the tenth pipeline L10;

[0011] A first master cylinder isolation valve B1 is arranged on the pipeline between the connection point p1 of the third pipeline L3 and the first pipeline L1 and the connection point p2 of the fifth pipeline L5 and the first pipeline L1; A second master cylinder isolation valve B2 is arranged on the pipeline between the connection point p3 of the fourth pipeline L4 and the second pipeline L2 and the connection point p4 of the sixth pipeline L6 and the second pipeline L2; A third pressure sensor S3 is also arranged on the second pipeline on the side of the connection point p3 close to the ESC.

[0012] Further, the control method includes a pedal decoupling mode control method, a by-wire control mode control method, a system self-check mode control method, a mechanical braking mode control method, an exhaust mode control method, and a fail-safe mode control method.

[0013] Further, the pedal decoupling mode control method includes:

[0014] When the power assist module U2 receives the pedal travel signal sent by U1, the controller controls the motor to operate according to the target current, and builds high hydraulic pressure through the power assist master cylinder; at this time, the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 are both closed, the first pedal decoupling valve D1 and the second pedal decoupling valve D2 are both opened, the first power assist valve A1 and the second power assist valve A2 are both opened, and the first exhaust valve C1 and the second exhaust valve C2 are both opened;

[0015] The high-pressure liquid established inside the first simulated master cylinder and the second simulated master cylinder passes through the first pedal decoupling valve D and the second pedal decoupling valve D in parallel, and enters the first pedal feel simulated load and the second pedal feel simulated load to achieve the pedal feel; the high-pressure liquid in the first power assist master cylinder and the second power assist master cylinder' respectively passes through the first power assist valve A1 and the second power assist valve A into the ESC and the brake to implement braking. The pedal feel circuit and the brake circuit are independent of each other to achieve complete decoupling;

[0016] When the brake pedal is released, the simulated master cylinder and the simulated load return to their original positions through the return spring, and the liquid returns to the brake fluid reservoir through the first exhaust valve C1 and the second exhaust valve C2 to achieve pressure relief; the controller controls the motor to rotate by identifying the pedal return signal to achieve pressure relief of the brake circuit.

[0017] Furthermore, the by-wire mode control method includes:

[0018] When the vehicle is running, if there is an external brake pressure request, the motor rotates with this as the target pressure to drive the motor, and builds oil pressure in the first power assist master cylinder and the second power assist master cylinder'; at this time, the controller controls the corresponding first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 to be both closed, and the pressure in the pedal feel circuit remains constant at atmospheric pressure; the controller controls the first power assist valve A1 and the second power assist valve A2 to be opened, and the first power assist master cylinder and the second power assist master cylinder' build pressure and enter the ESC and the brake to achieve by-wire braking without pedal force.

[0019] Furthermore, the system self-check mode control method includes: during system self-check, the sealing performance of the system can be checked in segments;

[0020] In the first stage of self-check, the controller controls the motor to operate, controls the first power assist valve A1 and the second power assist valve A2 to be both closed, and the high-pressure liquid in the power assist master cylinder is sealed in the pressure building valve for pressure holding. The pressure drop is detected through the first pressure sensor S1 and the second pressure sensor S2 to self-check the sealing performance in this section;

[0021] In the second stage of self-check, the controller controls the motor to operate, controls the first power assist valve A1 and the second power assist valve A2 to be both opened; the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 are both opened, the first pedal decoupling valve D1 and the second pedal decoupling valve D2 are both opened, the first exhaust valve C1 and the second exhaust valve C2 are both closed, and at the same time, a signal request is sent to the external ESC to block the liquid flow of the ESC;

[0022] The high-pressure liquid in the booster master cylinder passes through the first booster valve A1 and the second booster valve A2, and enters the first simulated master cylinder and the second simulated master cylinder' through the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2. Inside the first exhaust valve C1 and the second exhaust valve C2; it flows into the pedal simulation load through the first pedal decoupling valve D1 and the second pedal decoupling valve D2. The system detects the pressure drop through the first pressure sensor S1 and the second pressure sensor S2, and self-checks the sealing performance in this section;

[0023] For the third-stage self-check, the controller controls the motor to work, controls both the first booster valve A1 and the second booster valve A2 to open, and both the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 to close; the high-pressure liquid in the booster master cylinder enters the ESC and the brake 6, and the controller self-checks the sealing performance in this section through the third pressure sensor S3.

[0024] Furthermore, the mechanical braking mode control method includes: when the system is powered off, the booster enters the mechanical backup mode; both the first booster valve A1 and the second booster valve A2 are in the natural closed state, both the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 are in the natural open state, both the first exhaust valve C1 and the second exhaust valve C2 are in the natural open state, and both the first pedal decoupling valve D1 and the second pedal decoupling valve D2 are in the natural normally closed state; when the brake pedal is depressed, the brake hydraulic pressure in the simulated master cylinder directly enters the brake through the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2, realizing mechanical braking when the pedal is depressed.

[0025] Furthermore, the exhaust mode control method includes:

[0026] Internal exhaust mode: The controller controls the motor to work, both the first booster valve A1 and the second booster valve A2 are opened, both the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 are opened, both the first pedal decoupling valve D1 and the second pedal decoupling valve D2 are opened, both the first exhaust valve C1 and the second exhaust valve C2 are closed, and at the same time, a signal demand is sent to the external ESC to block the liquid flow of the ESC. At this time, a high pressure is formed inside the system. The controller continuously controls the first exhaust valve C1 to open and the second exhaust valve C2 to open, and the brake fluid is discharged into the reservoir tank. Then, the controller continuously controls the first exhaust valve C1 and the second exhaust valve C2 to close and open, and after multiple pressure releases, the internal exhaust is completed;

[0027] External exhaust mode: The controller controls the motor to work, controls both the first booster valve A1 and the second booster valve A2 to open, both the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 are closed, both the first pedal decoupling valve D1 and the second pedal decoupling valve D2 are opened, both the first exhaust valve C1 and the second exhaust valve C2 are opened, and the high-pressure brake fluid enters the brake, and manual exhaust is carried out through the exhaust valve screw of the brake to realize external circuit exhaust.

[0028] Furthermore, the failure backup mode control method includes:

[0029] Failure mode 1: When the first simulated master cylinder or the second simulated master cylinder fails (simulated master cylinder leakage or pedal sensor failure), the controller can implement normal braking on the vehicle according to the pedal signals of the remaining normal pedal master cylinders, and the braking capacity of the system remains unchanged;

[0030] Failure mode 2: When the first motor or the second motor fails or leaks, the system compensates for the target pressure to enable the system to have a braking capacity of more than 50%;

[0031] Failure mode 3: When both the first simulated master cylinder and the second simulated master cylinder fail, the system cannot identify the pedal stroke signal at this time, and the system will implement braking according to the specified braking pressure to ensure that the system has a medium-strength braking capacity;

[0032] Failure mode 4: When both the first motor and the second motor fail, the system enters the mechanical backup mode, and at the same time the system sends a braking demand to the external (ESC) to ensure that the vehicle has a medium-strength braking capacity;

[0033] Failure mode 5: The system enters the mechanical braking mode, and the vehicle has emergency braking ability.

[0034] The beneficial effects and features of the present invention are:

[0035] 1. The dual-redundancy electronic braking booster system of the present invention includes two modules: a pedal feel simulator and an electronic booster unit. The pedal simulator module uses a double-linkage pedal to independently collect the braking pedal feel signals respectively, achieving mutual redundancy. The electronic booster unit module internally integrates dual booster motors and dual independent circuits, which respectively assist the two circuits of the braking system to form a dual booster unit. The dual booster units coordinate and are redundant with each other, and can realize multiple functional modes such as by-wire assistance, system self-check, failure backup, mechanical backup, filling and exhausting;

[0036] 2. The dual-redundancy electronic braking booster system of the present invention can expand the boosting capacity of the electronic booster to cover all N2-class vehicles through dual-motor boosting. At the same time, with a dual-circuit independent design, the system has a multi-level backup ability, and the system safety performance is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is the working principle of the dual-redundancy electronic booster system of the preferred embodiment of the present invention;

[0038] Figure 2 is the structure diagram of the dual-redundancy electronic booster system and the schematic diagram of the pedal decoupling mode of the preferred embodiment of the present invention (the thick line is the relevant line in this mode);

[0039] Figure 3 Schematic diagram of the electronic brake mode for a preferred embodiment of the present invention (bold lines represent relevant circuits in this mode);

[0040] Figure 4 Schematic diagram of the first system self - check mode for a preferred embodiment of the present invention (bold lines represent relevant circuits in this mode);

[0041] Figure 5 Schematic diagram of the second system self - check mode for a preferred embodiment of the present invention (bold lines represent relevant circuits in this mode);

[0042] Figure 6 Schematic diagram of the third system self - check mode for a preferred embodiment of the present invention (bold lines represent relevant circuits in this mode);

[0043] Figure 7 Schematic diagram of the mechanical backup mode for a preferred embodiment of the present invention (bold lines represent relevant circuits in this mode);

[0044] Figure 8 Schematic diagram of the internal exhaust mode for a preferred embodiment of the present invention (bold lines represent relevant circuits in this mode);

[0045] Figure 9 Schematic diagram of the external exhaust mode for a preferred embodiment of the present invention (bold lines represent relevant circuits in this mode);

[0046] Figure 10 Schematic diagram of the failure backup mode for a preferred embodiment of the present invention;

[0047] The reference numerals in the figure respectively represent: 1 - brake pedal, 2 - pedal position sensor, 2' - second pedal feel sensor, 3 - first analog master cylinder, 3' - second analog master cylinder, 4 - brake fluid reservoir, 5 - first pedal feel analog load, 5' - second pedal feel analog load, 6 - brake, 7 - first one - way valve, 7' - second one - way valve, 8 - first power assist master cylinder, 8' - second power assist master cylinder, 9 - first motor, 9' - second motor, 10 – first motor current sensor, 10' - second motor current sensor, 11 - first motor position sensor, 11' - second motor position sensor, U1 - pedal module, U2 - power assist module, S1 - first pressure sensor, S2 - second pressure sensor, S3 - third pressure sensor, A1 - first power assist valve, A2 - second power assist valve, B1 - first master cylinder isolation valve, B2 - second master cylinder isolation valve, C1 - first exhaust valve, C2 - second exhaust valve, D1 - first pedal decoupling valve, D2 - second pedal decoupling valve. Detailed implementation manners

[0048] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work shall fall within the protection scope of the present invention.

[0049] Please refer to Figure 1 , the working principle of the dual-redundancy electronic booster is as Figure 1 : When the driver steps on the brake pedal, pressure is established in the simulated master cylinder, and the liquid enters the pedal simulation load to generate a pedal feedback feeling.

[0050] At the same time, the pedal feel sensor sends the pedal travel signal to the controller. The controller calculates the real-time target pressure through the stroke-pressure curve (set value); then calculates the real-time target speed of the motor according to the motor characteristics (motor external characteristic value) and the actual pressure P fed back by the pressure sensor; then calculates the target current of the motor according to the motor characteristic value and the actual speed value fed back by the motor position sensor, controls the motor to rotate, and establishes a braking pressure in the booster master cylinder.

[0051] The controller controls the opening and closing of four valves in the hydraulic flow channel according to various functional modes to achieve corresponding functions.

[0052] The controller can respond to external brake pressure requests or send control requirements to external controllers.

[0053] Please refer to Figure 2 , the present invention relates to a dual-redundancy electronic braking booster system, including a pedal module U1 and a booster module U2. The pedal module U1 includes a linkage pedal 1, a first simulated master cylinder 3 and a second simulated master cylinder 3';

[0054] The linkage pedal 1 is connected to the first simulated master cylinder 3 and the second simulated master cylinder 3' through two pipelines. A first pedal feel sensor 2 is arranged on the pipeline between the first simulated master cylinder 3 and the linkage pedal 1, and a second pedal feel sensor 2' is arranged on the pipeline between the second simulated master cylinder 3' and the linkage pedal 1. When the driver applies a pedal force to the linkage pedal 1, the linkage pedal 1 pushes the two simulated master cylinders to establish hydraulic pressure at the same time. The first pedal feel sensor 2 and the second pedal feel sensor 2' send the pedal travel signal to the ECU controller;

[0055] The booster module U2 is connected to U1 through a pipeline. The booster module U2 is externally connected to the ESC, and the ESC is connected to the brake 6.

[0056] Please refer to Figure 2, the boosting module U2 includes a first pipeline L1, a second pipeline L2, a third pipeline L3, a fourth pipeline L4, a fifth pipeline L5, a sixth pipeline L6, a seventh pipeline L7, an eighth pipeline L8, a ninth pipeline L9, a tenth pipeline L10 and a brake oil pot 4; one ends of the first pipeline L1 and the second pipeline L2 are respectively connected to a first simulated master cylinder 3 and a second simulated master cylinder 3', and the other ends are both connected to the vehicle ESC, and the ESC is communicated with a brake 6;

[0057] The third pipeline L3 is connected to the first pipeline L1, and a first boosting valve A1, a first pressure sensor S1, a first boosting master cylinder 8, a first motor 9 and a first motor current sensor 10 are sequentially arranged on the third pipeline L3, and a first motor position sensor 11 is arranged on the first motor 9; the fourth pipeline L4 is connected to the second pipeline L2, and a second boosting valve A2, a second pressure sensor S2, a second boosting master cylinder 8', a second motor 9' and a second motor current sensor 10' are sequentially arranged on the fourth pipeline L4, and a second motor position sensor 11' is arranged on the second motor 9'; the first boosting master cylinder 8 is connected to the brake oil pot 4 through the seventh pipeline L7, and a first one-way valve 7 is arranged on the seventh pipeline L7; the second boosting master cylinder 8' is connected to the brake oil pot 4 through the eighth pipeline L8, and a second one-way valve 7' is arranged on the eighth pipeline L8;

[0058] One end of the fifth pipeline L5 is connected to the first pipeline L1, and the other end is connected to the brake oil pot 4. A first pedal decoupling valve D1 and a first pedal feel simulation load 5 are arranged on the fifth pipeline L5; one end of the sixth pipeline L6 is connected to the second pipeline L2, and the other end is connected to the brake oil pot 4. A second pedal decoupling valve D2 and a second pedal feel simulation load 5' are arranged on the sixth pipeline L6;

[0059] The first simulated master cylinder 3 is connected to the brake oil pot 4 through the ninth pipeline L9, and a first exhaust valve C1 is arranged on the ninth pipeline L9; the second simulated master cylinder 3' is connected to the second simulated master cylinder 3' through the tenth pipeline L10; a second exhaust valve C2 is arranged on the tenth pipeline L10;

[0060] A first master cylinder isolation valve B1 is arranged on the pipeline between the connection point p1 of the third pipeline L3 and the first pipeline L1 and the connection point p2 of the fifth pipeline L5 and the first pipeline L1; a second master cylinder isolation valve B2 is arranged on the pipeline between the connection point p3 of the fourth pipeline L4 and the second pipeline L2 and the connection point p4 of the sixth pipeline L6 and the second pipeline L2; a third pressure sensor S3 is further arranged on the second pipeline on the side of the connection point p3 close to the ESC.

[0061] The control method of the dual-redundancy electronic brake booster system includes a pedal decoupling mode control method, a by-wire control mode control method, a system self-check mode control method, a mechanical braking mode control method, an exhaust mode control method, and a fail-safe mode control method.

[0062] The pedal decoupling mode control method includes:

[0063] After the boost module U2 receives the pedal stroke signal sent by U1, the controller controls the motor 9 to operate according to the target current, and builds high hydraulic pressure through the boost master cylinder 8; at this time, the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 are both closed, the first pedal decoupling valve D1 and the second pedal decoupling valve D2 are both opened, the first boost valve A1 and the second boost valve A2 are both opened, and the first exhaust valve C1 and the second exhaust valve C2 are both opened;

[0064] The high-pressure liquid established inside the first simulated master cylinder 3 and the second simulated master cylinder 3' passes through the first pedal decoupling valve D1 or the second pedal decoupling valve D2 in parallel, and enters the first pedal feel simulation load 5 and the second pedal feel simulation load 5' to achieve pedal feel; the high-pressure liquid in the first boost master cylinder 8 and the second boost master cylinder 8' respectively passes through the first boost valve A1 and the second boost valve A, and enters the ESC and the brake 6 to implement braking. The pedal feel circuit and the braking circuit are independent of each other to achieve complete decoupling;

[0065] When the brake pedal is released, the simulated master cylinder and the simulated load return to their original positions through the return spring, and the liquid returns to the brake fluid reservoir 4 through the first exhaust valve C1 and the second exhaust valve C2 to achieve pressure relief; the controller controls the motor 9 to rotate by identifying the pedal return signal to achieve pressure relief of the braking circuit.

[0066] The by-wire mode control method includes:

[0067] Please refer to Figure 3 , when the vehicle is running, if there is an external braking pressure request, the motor rotates with this as the target pressure to drive the motor, and builds oil pressure in the first boost master cylinder 8 and the second boost master cylinder 8'; at this time, the controller controls the corresponding first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 to be both closed, and the pressure in the pedal feel circuit remains constant at normal pressure; the controller controls the first boost valve A1 and the second boost valve A2 to be opened, and the first boost master cylinder 8 and the second boost master cylinder 8' build pressure and enter the ESC and the brake to achieve by-wire braking without pedal force.

[0068] The system self-check mode control method includes: during system self-check, the sealing performance inside the system can be checked in segments;

[0069] Please refer to Figure 4, For the first-stage self-check, the controller controls the motor to operate, closes both the first booster valve A1 and the second booster valve A2. The high-pressure liquid in the booster master cylinder is sealed in the pressure building valve for pressure holding. The pressure drops are detected by the first pressure sensor S1 and the second pressure sensor S2 to self-check the sealing performance in this section.

[0070] Please refer to Figure 5 , For the second-stage self-check, the controller controls the motor to operate, opens both the first booster valve A1 and the second booster valve A2; opens both the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2, opens both the first pedal decoupling valve D1 and the second pedal decoupling valve D2, closes both the first exhaust valve C1 and the second exhaust valve C2, and simultaneously sends a signal request to the external ESC to block the liquid flow of the ESC.

[0071] The high-pressure liquid in the booster master cylinder passes through the first booster valve A1 and the second booster valve A2, then through the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2, and enters the first simulation master cylinder 3 and the second simulation master cylinder 3'. Inside the first exhaust valve C1 and the second exhaust valve C2; it flows into the pedal simulation load through the first pedal decoupling valve D1 and the second pedal decoupling valve D2. The system detects the pressure drop through the first pressure sensor S1 and the second pressure sensor S2 to self-check the sealing performance in this section.

[0072] Please refer to Figure 6 , For the third-stage self-check: The controller controls the motor to operate, opens both the first booster valve A1 and the second booster valve A2, and closes both the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2; the high-pressure liquid in the booster master cylinder enters the ESC and the brake 6, and the third pressure sensor S3 is used to self-check the sealing performance in this section.

[0073] Please refer to Figure 7 , The mechanical braking mode control method includes: when the system loses power, the booster enters the mechanical backup mode; at this time, both the first booster valve A1 and the second booster valve A2 are in the natural closed state, both the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 are in the natural open state, both the first exhaust valve C1 and the second exhaust valve C2 are in the natural open state, and both the first pedal decoupling valve D1 and the second pedal decoupling valve D2 are in the natural normally closed state; when the brake pedal is depressed, the brake hydraulic pressure in the simulation master cylinder directly enters the brake through the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 to achieve mechanical braking when the pedal is depressed.

[0074] The exhaust mode control method includes:

[0075] Please refer to Figure 8, Internal exhaust mode: The controller controls the motor to operate. The first booster valve A1 and the second booster valve A2 are both opened. The first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 are both opened. The first pedal decoupling valve D1 and the second pedal decoupling valve D2 are both opened. The first exhaust valve C1 and the second exhaust valve C2 are both closed. At the same time, a signal demand is sent to the external ESC to block the liquid flow of the ESC. At this time, a high pressure is formed inside the system. The controller continuously controls the first exhaust valve C1 to open and the second exhaust valve C2 to open. The brake fluid is discharged into the reservoir, and then continuously controls the first exhaust valve C1 and the second exhaust valve C2 to close and open. After multiple pressure releases, the internal exhaust is completed;

[0076] Please refer to Figure 9 , External exhaust mode: The controller controls the motor to operate, controls the first booster valve A1 and the second booster valve A2 to be both opened, the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 to be both closed, the first pedal decoupling valve D1 and the second pedal decoupling valve D2 to be both opened, the first exhaust valve C1 and the second exhaust valve C2 to be both opened. The high-pressure brake fluid enters the brake, and manual exhaust is performed through the exhaust valve screw of the brake to achieve external circuit exhaust.

[0077] The failure backup mode control method includes:

[0078] Failure mode 1: When the first simulated master cylinder 3 or the second simulated master cylinder 3' fails (simulated master cylinder leakage or pedal sensor failure), the controller can perform normal braking on the vehicle according to the pedal signals of the remaining normal pedal master cylinders, and the braking ability of the system remains unchanged;

[0079] Failure mode 2: When the first motor 9 or the second motor 9' fails or leaks, the system compensates for the target pressure so that the system has a braking ability of more than 50%;

[0080] Failure mode 3: When the first simulated master cylinder 3 and the second simulated master cylinder 3' fail simultaneously, at this time the system cannot identify the pedal stroke signal, and the system will perform braking according to the specified braking pressure to ensure that the system has a medium-strength braking ability;

[0081] Failure mode 4: When the first motor 9 and the second motor 9' fail simultaneously, the system enters the mechanical backup mode, and at the same time the system sends a braking demand to the external (ESC) to ensure that the vehicle has a medium-strength braking ability;

[0082] Failure mode 5: The system enters the mechanical braking mode, and the vehicle has emergency braking ability.

[0083] The above has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the structural relationship and principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A dual-redundancy electronic brake booster system, characterized in that, It includes a pedal module U1 and an assist module U2. The pedal module U1 includes a linkage pedal (1), a first analog master cylinder (3), and a second analog master cylinder (3'); The linkage pedal (1) is connected to the first analog master cylinder (3) and the second analog master cylinder (3') through two pipelines. A first pedal feel sensor (2) is arranged on the pipeline between the first analog master cylinder (3) and the linkage pedal (1), and a second pedal feel sensor (2') is arranged on the pipeline between the second analog master cylinder (3') and the linkage pedal (1). When the driver applies a pedal force to the linkage pedal (1), the linkage pedal (1) pushes the two analog master cylinders to establish hydraulic pressure simultaneously. The first pedal feel sensor (2) and the second pedal feel sensor (2') send the pedal travel signal to the ECU controller; The assist module U2 is connected to U1 through a pipeline. The assist module U2 is externally connected to the ESC, and the ESC is connected to the brake 6; The assist module U2 includes a first pipeline L1, a second pipeline L2, a third pipeline L3, a fourth pipeline L4, a fifth pipeline L5, a sixth pipeline L6, a seventh pipeline L7, an eighth pipeline L8, a ninth pipeline L9, a tenth pipeline L10, and a brake oil pot 4. One ends of the first pipeline L1 and the second pipeline L2 are respectively connected to the first analog master cylinder (3) and the second analog master cylinder (3'), and the other ends are both connected to the vehicle ESC. The ESC is connected to the brake (6); The third pipeline L3 is connected to the first pipeline L1. A first assist valve A1, a first pressure sensor S1, a first assist master cylinder (8), a first motor (9), and a first motor current sensor (10) are sequentially arranged on the third pipeline L3. A first motor position sensor (11) is arranged on the first motor (9). The fourth pipeline L4 is connected to the second pipeline L2. A second assist valve A2, a second pressure sensor S2, a second assist master cylinder (8'), a second motor (9'), and a second motor current sensor (10') are sequentially arranged on the fourth pipeline L4. A second motor position sensor (11') is arranged on the second motor (9'). The first assist master cylinder (8) is connected to the brake oil pot (4) through the seventh pipeline L7, and a first one-way valve (7) is arranged on the seventh pipeline L7. The second assist master cylinder (8') is connected to the brake oil pot (4) through the eighth pipeline L8, and a second one-way valve (7') is arranged on the eighth pipeline L8; One end of the fifth pipeline L5 is connected to the first pipeline L1, and the other end is connected to the brake oil pot (4). A first pedal decoupling valve D1 and a first pedal feel simulation load (5) are arranged on the fifth pipeline L5. One end of the sixth pipeline L6 is connected to the second pipeline L2, and the other end is connected to the brake oil pot (4). A second pedal decoupling valve D2 and a second pedal feel simulation load (5') are arranged on the sixth pipeline L6; The first analog master cylinder (3) is connected to the brake oil pot (4) through the ninth pipeline L9, and a first exhaust valve C1 is arranged on the ninth pipeline L9. The second analog master cylinder (3') is connected to the second analog master cylinder (3') through the tenth pipeline L10. A second exhaust valve C2 is arranged on the tenth pipeline L10; A first master cylinder isolation valve B1 is provided on the pipeline between the connection point p1 of the third pipeline L3 and the first pipeline L1 and the connection point p2 of the fifth pipeline L5 and the first pipeline L1; a second master cylinder isolation valve B2 is provided on the pipeline between the connection point p3 of the fourth pipeline L4 and the second pipeline L2 and the connection point p4 of the sixth pipeline L6 and the second pipeline L2; a third pressure sensor S3 is further provided on the second pipeline on the side of the connection point p3 close to the ESC.

2. The control method of the dual-redundancy electronic brake booster system according to claim 1, wherein The control method includes a pedal decoupling mode control method, a by-wire control mode control method, a system self-check mode control method, a mechanical braking mode control method, an exhaust mode control method, and a fail-safe mode control method.

3. The control method of the dual-redundancy electronic brake booster system according to claim 2, characterized in that The pedal decoupling mode control method includes: When the boost module U2 receives the pedal travel signal sent by U1, the controller controls the motor 9 to work according to the target current, and builds high hydraulic pressure through the boost master cylinder (8); at this time, the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 are both closed, the first pedal decoupling valve D1 and the second pedal decoupling valve D2 are both opened, the first boost valve A1 and the second boost valve A2 are both opened, the first exhaust valve C1, The second exhaust valve C2 are both opened; The high-pressure liquid established inside the first simulation master cylinder (3) and the second simulation master cylinder (3') passes through the first pedal decoupling valve D1 and the second pedal decoupling valve D2 in parallel and enters the first pedal feel simulation load (5) and the second pedal feel simulation load (5') to achieve the pedal feel; the high-pressure liquid in the first boost master cylinder (8) and the second boost master cylinder (8’) respectively passes through the first boost valve A1 and the second boost valve A and enters the ESC and the brake (6) to implement braking. The pedal feel circuit and the braking circuit are independent of each other to achieve complete decoupling; When the brake pedal is released, the simulation master cylinder and the simulation load return to their original positions through the return spring, and the liquid returns to the brake oil pot (4) through the first exhaust valve C1 and the second exhaust valve C2 to achieve pressure relief; the controller controls the motor (9) to rotate by identifying the pedal return signal to achieve pressure relief of the braking circuit.

4. The control method of the dual-redundancy electronic brake booster system according to claim 2, characterized in that, The by-wire control mode control method includes: When the vehicle is running, if there is an external braking pressure request, the motor rotates with this as the target pressure to build oil pressure in the first boost master cylinder 8 and the second boost master cylinder 8’; at this time, the controller controls the corresponding first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 to be both closed, and the pressure in the pedal feel circuit remains constant at normal pressure; the controller controls the first boost valve A1 and the second boost valve A2 to be opened, and the first boost master cylinder (8) and the second boost master cylinder (8’) build pressure and enter the ESC and the brake to achieve by-wire braking without pedal force.

5. The control method of the dual-redundancy electronic brake booster system according to claim 2, wherein, The system self-check mode control method includes: during system self-check, the sealing performance of the system can be checked in segments; In the first stage of self-check, the controller controls the motor to work, controls the first boost valve A1 and the second boost valve A2 to be both closed, and the high-pressure liquid in the boost master cylinder is sealed in the pressure building valve for pressure holding. The pressure drop is detected through the first pressure sensor S1 and the second pressure sensor S2 to self-check the sealing performance in this section; Second-stage self-check: The controller controls the motor to operate, and controls both the first booster valve A1 and the second booster valve A2 to open; both the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 open, both the first pedal decoupling valve D1 and the second pedal decoupling valve D2 open, both the first exhaust valve C1 and the second exhaust valve C2 close, and at the same time send a signal request to the external ESC to block the ESC liquid flow; The high-pressure liquid in the booster master cylinder passes through the first booster valve A1 and the second booster valve A2, passes through the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2, and enters the first simulated master cylinder (3) and the second simulated master cylinder (3'); within the first exhaust valve C1 and the second exhaust valve C2; flows into the pedal simulation load through the first pedal decoupling valve D1 and the second pedal decoupling valve D2. The system detects the pressure drop through the first pressure sensor S1 and the second pressure sensor S2 to self-check the sealing performance in this section; Third-stage self-check: The controller controls the motor to operate, and controls both the first booster valve A1 and the second booster valve A2 to open, and both the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 to close; the high-pressure liquid in the booster master cylinder enters the ESC and the brake (6), and the third pressure sensor S3 is used to self-check the sealing performance in this section.

6. The control method of the dual-redundancy electronic brake booster system according to claim 2, characterized in that, The mechanical braking mode control method includes: when the system is powered off, the booster enters the mechanical backup mode; both the first booster valve A1 and the second booster valve A2 are in the natural closed state, both the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 are in the natural open state, both the first exhaust valve C1 and the second exhaust valve C2 are in the natural open state, and both the first pedal decoupling valve D1 and the second pedal decoupling valve D2 are in the natural normally closed state; when the brake pedal is depressed, the brake hydraulic pressure in the simulated master cylinder directly enters the brake through the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2, realizing mechanical braking when the pedal is depressed.

7. The control method of the dual-redundancy electronic brake booster system according to claim 2, wherein The exhaust mode control method includes: Internal exhaust mode: The controller controls the motor to operate, both the first booster valve A1 and the second booster valve A2 open, both the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 open, both the first pedal decoupling valve D1 and the second pedal decoupling valve D2 open, one Both the first exhaust valve C1 and the second exhaust valve C2 close, and at the same time send a signal request to the external ESC to block the ESC liquid flow. At this time, a high pressure is formed inside the system. The controller continuously controls the first exhaust valve C1 to open and the second exhaust valve C2 to open, and the brake fluid is discharged into the reservoir tank. Then, the controller continuously controls the first exhaust valve C1 and the second exhaust valve C2 to close and open. After multiple pressure reliefs, the internal exhaust is completed; External exhaust mode: The controller controls the motor to operate, controls both the first booster valve A1 and the second booster valve A2 to open, both the first master cylinder isolation valve B1 and the second master cylinder isolation valve B2 close, both the first pedal decoupling valve D1 and the second pedal decoupling valve D2 open, both the first exhaust valve C1 and the second exhaust valve C2 open, the high-pressure brake fluid enters the brake, and manual exhaust is performed through the exhaust valve screw of the brake to realize external circuit exhaust. The failure backup mode control method includes:

8. The control method of the dual-redundancy electronic brake booster system according to claim 2, wherein, ​ Failure mode 1: When the first simulated master cylinder (3) or the second simulated master cylinder (3’) fails, the controller implements normal braking on the vehicle according to the pedal signals of the remaining normal pedal master cylinders, and the braking capacity of the system remains unchanged; Failure mode 2: When the first motor (9) or the second motor (9’) fails or leaks, the system compensates for the target pressure so that the system has a braking capacity of more than 50%; Failure mode 3: When the first simulated master cylinder (3) and the second simulated master cylinder (3’) fail simultaneously, the system cannot recognize the pedal stroke signal at this time, and the system will implement braking according to the specified braking pressure to ensure that the system has a medium-strength braking capacity; Failure mode 4: When the first motor 9 and the second motor (9’) fail simultaneously, the system enters the mechanical backup mode, and at the same time the system sends a braking demand to the external (ESC) to ensure that the vehicle has a medium-strength braking capacity; Failure mode 5: The system enters the mechanical braking mode, and the vehicle has emergency braking capacity.

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