WO2021004526A1

WO2021004526A1 - Electro-hydraulic coupling drive-by-wire power-assisted braking system and method

Info

Publication number: WO2021004526A1
Application number: PCT/CN2020/101317
Authority: WO
Inventors: 施正堂; 孙怡鹏; 张赫; 杨阳; 张绍丹; 陈汉涛; 陈珍颖
Original assignee: 浙江亚太机电股份有限公司
Priority date: 2019-07-11
Filing date: 2020-07-10
Publication date: 2021-01-14
Also published as: CN110406518A

Abstract

An electro-hydraulic coupling drive-by-wire power-assisted braking system, comprising a drive-by-wire power-assisted system and an electro-hydraulic coupling braking system which are designed in a manner of integrating with IBS, wherein the drive-by-wire power-assisted system comprises a pedal execution unit (1) and a pressure building unit (2), and the electro-hydraulic coupling braking system comprises an ABS anti-lock braking system (3), a hub motor driving system, and a hydraulic brake; the pedal execution unit (1) comprises a master cylinder (9) and an input push rod (12); a brake pedal (4) and a piston push rod for executing braking in the master cylinder (9) are not directly connected in a normal state, so that full decoupling is achieved, and the brake pedal (4) detects data by means of a pressure sensor and transmits the data to a brake control system ECU (14) to act on the braking. According to the present invention, the pressure build-up time is shortened, the noise can be effectively reduced, the full decoupling of the brake pedal and the push rod of the master cylinder is implemented, the regenerative energy recovery efficiency of the motor is effectively improved, the energy consumption of the whole vehicle is reduced, the braking requirement of the whole vehicle is implemented by maximally utilizing the electromagnetic braking of the motor, the endurance mileage is improved, and the safety and the stability of vehicle driving are improved. The present invention further relates to an electro-hydraulic coupling braking method.

Description

Electro-hydraulic coupling wire control booster braking system and method

Technical field

The invention relates to the field of new energy vehicles, and in particular to an electro-hydraulic coupling braking scheme for realizing line-control assist and a line-control assist scheme adopting a distributed drive system of a new energy automobile braking system.

Background technique

With the impact of domestic environmental pollution and energy crisis, more and more car companies are focusing on product development in the field of new energy vehicles. However, because new energy vehicles do not have an engine and lack a vacuum source when braking, they often need to match a vacuum pump and a vacuum booster. The system has the disadvantages of large footprint, high noise when the vacuum pump is working, slow response time and low efficiency. At the same time, the current pure electric vehicles on the market mostly adopt the form of central drive. The electromagnetic brake realized by regenerative energy recovery has the disadvantages of small braking force, low efficiency, and not fully coupled with the hydraulic braking system.

As the popularity of new energy vehicles becomes more and more widespread, how to integrate the wire-controlled power-assisted system, and to couple the electromagnetic brake of the drive motor with the traditional ABS anti-lock brake system to achieve efficient energy recovery and electro-hydraulic coupling braking has become the current Problems that the automakers need to solve urgently.

Summary of the invention

In order to solve the problems existing in the background art, the present invention provides an electro-hydraulic coupling braking solution that realizes a wire-controlled assist and a wire-controlled assist solution using a distributed drive system.

The technical scheme adopted by the present invention is:

1. An electro-hydraulic coupling wire-controlled power-assisted braking system:

The system includes integrated IBS (“Integrated Braking System”) designed by-wire power assist system and electro-hydraulic coupling braking system. The wire-controlled power assist system includes pedal execution unit and pressure building unit, and electro-hydraulic coupling braking system includes ABS anti-lock braking system. , Hydraulic brake, wheel hub motor drive system and hydraulic brake integrated in the wheel hub motor drive system; the pedal execution unit includes a brake fluid oil pot, a master cylinder and an input push rod. The brake pedal is connected to one end of the input push rod. A displacement sensor is installed near the rod to detect the displacement of the input push rod. The other end of the input push rod is installed in the master cylinder, and there is a gap between the other end of the input push rod and one end of the piston push rod in the master cylinder. There is a pressure sensor, and the output end of the other end of the piston push rod in the master cylinder is connected to the ABS input valve port of the ABS anti-lock system.

In the present invention, the brake pedal and the piston push rod for braking in the master cylinder are not directly connected under normal conditions, so that the brake pedal and the master cylinder are fully decoupled from pressure build-up, and there is no mechanical hard connection. The action of the brake pedal is transmitted to the brake control system ECU through the pressure sensor detection data to act on the brake.

The pressure building unit includes the brake control system ECU, brushless motor and auxiliary cylinder. The displacement sensor and the brake control system ECU are connected through a low-voltage wiring harness. The pressure sensor and the brake control system ECU are connected through a low-voltage wiring harness. The brake control system ECU and the The brush motor is connected through a low-voltage wiring harness, and the output end of the brushless motor is connected to the auxiliary cylinder. The brake control system ECU controls the brushless motor to drive the auxiliary cylinder to form the required oil pressure; the bottom of the brake fluid oil tank is equipped with a brake fluid oil tank outlet The oil port, the oil outlet of the brake fluid oil pot is connected to the oil inlet of the auxiliary cylinder of the auxiliary cylinder of the pressure building unit through the brake hose, and the auxiliary cylinder oil outlet of the auxiliary cylinder of the pressure building unit passes through the auxiliary cylinder brake hard pipe Connected to the oil inlet of the master cylinder of the pedal actuator unit, and the oil outlet of the master cylinder of the master cylinder of the pedal actuator unit is connected to the ABS input valve port and ABS output valve port of the ABS anti-lock system through the ABS brake pipe It is connected to the brake wheel cylinder input end of the hydraulic brake through the ABS brake pipe.

The pedal execution unit and pressure building unit of the wire-controlled power assist system are installed in the front engine room of the vehicle.

The brake pedal is connected with the input push rod of the pedal execution unit, the input push rod is connected with the pedal simulation unit, and the pedal simulation unit performs sensory feedback on the brake pedal stepped on by the driver.

The hydraulic brake is installed in the in-wheel motor drive system and works together with the electromagnetic brake part of the motor in the in-wheel motor drive system.

The in-wheel motor drive system already has a motor electromagnetic brake part and a motor regenerative energy recovery part. The motor electromagnetic brake part and the motor regenerative energy recovery part are essentially parts composed of the same motor coil rotor and stator. Regenerative energy recovery or electromagnetic braking of the motor is the basic function of the motor as a generator when the whole vehicle is braked. In fact, it is a different perspective of the same function. From the perspective of energy flow, the current from the motor to the battery is regenerative energy recovery; from the perspective of vehicle braking, it is the electromagnetic brake of the motor.

The displacement sensor adopts a digital displacement sensor, outputs PWM waveform, and directly obtains the digital quantity of pedal displacement.

The invention realizes the full decoupling of the brake pedal and the pressure buildup of the master cylinder, and simultaneously adopts the distributed drive system and the ABS anti-lock braking system to realize electro-hydraulic coupling braking, and can be used in the integrated wire-controlled power assist system of new energy vehicles.

2. An electro-hydraulic coupling braking method that realizes wire-controlled assist:

Work according to the following method, the working process is as follows:

1) When the driver releases the accelerator pedal of the vehicle, the vehicle enters a coasting state. At this time, the motor regenerative energy recovery part of the in-wheel motor drive system does not work;

2) When the driver steps on the brake pedal of the vehicle, the motor regenerative energy recovery part of the in-wheel motor drive system works and at the same time provides electromagnetic braking force to the whole vehicle:

If the electromagnetic braking force provided by the electromagnetic brake part of the in-wheel motor drive system can meet the braking requirements of the whole vehicle, the whole vehicle will be braked completely by electromagnetic braking, and the hydraulic brake will not intervene in the work;

If the electromagnetic braking force provided by the electromagnetic brake part of the in-wheel motor drive system cannot meet the braking requirements of the whole vehicle, the whole vehicle cannot be braked completely by electromagnetic braking. The hydraulic brake intervenes and the electromagnetic brake works together to provide braking force. The brake control system ECU runs according to the data signal sent by the wheel hub motor drive system to control the hydraulic brake to supplement the additional required braking force;

3) When the driver steps on the brake pedal of the vehicle and the vehicle speed gradually decreases and is less than the preset critical value, the electromagnetic brake first exits, and then the braking force provided by the hydraulic brake is gradually reduced to realize electro-hydraulic coupling braking;

4) When the driver steps on the brake pedal of the vehicle and the vehicle brakes urgently and the wheels lock up, the electromagnetic brake will exit work at this time:

If the wheels do not lock up after the electromagnetic brake is out of work, the whole vehicle can be braked by adjusting the brake pressure of the hydraulic brake;

If the wheels are still locked after the electromagnetic brake is out of work, the ABS anti-lock brake system will intervene to reduce the brake fluid pressure of the hydraulic brake, reduce the wheel braking force, and realize the anti-lock function.

In the step 2), the brake control system ECU operates to control the hydraulic brake to supplement the additional required braking force according to the data signal sent by the in-wheel motor drive system, specifically:

2.1) During the normal pressure building process of the driver shallowly depressing the brake pedal, the displacement sensor detects the displacement of the input push rod; the brake control system ECU receives the displacement of the input push rod to generate the braking force required by the vehicle, and then The pressure building unit sends a pressure building signal to the pressure building unit. The pressure building unit drives the auxiliary cylinder to generate oil pressure through a brushless motor. The oil pressure is transmitted to the master cylinder piston of the master cylinder through the auxiliary cylinder brake pipe to form the brake pressure. The pressure sensor monitors the brake pressure in the master cylinder, sends the signal to the brake control system ECU to determine whether the brake deceleration requirement is reached, and feeds back the brake pressure established by the control in real time to the brake control system ECU;

2.2) When the pressure building unit fails, after the driver depresses the brake pedal deeply, the displacement of the input push rod increases, and the input push rod overcomes the gap between the piston push rod of the master cylinder and the piston push rod of the master cylinder. The hard connection of the contact pushes the piston push rod of the master cylinder to build up the braking pressure to achieve braking, thereby realizing the mechanical backup of the electro-hydraulic braking, which is equivalent to the hydraulic braking of the whole vehicle without assistance.

The system of the present invention realizes the full decoupling of the brake pedal and the push rod of the master cylinder, and the pressure building unit builds pressure to the master cylinder through electronic control. At the same time, the brake control system ECU distributes the electro-hydraulic coupling braking force to maximize the use of the electromagnetic braking force provided by the motor's regenerative energy recovery to brake the entire vehicle, improve system efficiency, and reduce vehicle energy consumption. If the required braking force is greater than the electromagnetic braking force of the motor, ABS adjusts the brake fluid pressure of each wheel cylinder to realize electro-hydraulic coupling braking.

The beneficial effects of the present invention are:

1. The present invention uses an IBS wire-controlled booster system instead of traditional vacuum pumps and vacuum boosters, and uses a brushless motor to build system pressure and shorten the pressure building time; at the same time, it effectively reduces the noise generated by the vacuum pump in the front cabin.

2. The IBS brake-by-wire system of the present invention can realize the full decoupling of the brake pedal and the push rod of the master cylinder. The pedal simulator can simulate the brake pedal feel, realize the brake-by-wire function, and provide technical support for unmanned driving.

3. The invention combines the in-wheel motor direct drive system to effectively improve the efficiency of motor regeneration energy recovery, reduce the energy consumption of the entire vehicle, and increase the cruising range.

4. The present invention realizes electro-hydraulic coupling braking, and maximizes the use of electric motor electromagnetic braking to achieve vehicle braking requirements. The ABS anti-lock braking system can adjust wheel cylinder pressure to prevent wheels from locking and improve the safety and stability of the vehicle. .

Description of the drawings

Figure 1 is a schematic diagram of the structure of the wire-controlled power assist and electro-hydraulic coupling braking system.

Figure 2 is a schematic diagram of the connection of the wire-controlled power assist and electro-hydraulic coupling braking system.

Figure 3 is a schematic diagram of the structure of the pedal actuator of the wire-controlled power assist system.

Figure 4 is a schematic diagram of the pressure building unit of the wire-controlled power assist system.

Figure 5 is a schematic diagram of the ABS anti-lock system structure.

In the figure: 1. Pedal execution unit, 2. Pressure building unit, 3. ABS anti-lock braking system, 4. Brake pedal, 5. Brake hose, 6. Brake hard tube for auxiliary cylinder, 7. Brake fluid Oil pot, 8, brake fluid oil pot outlet, 9, master cylinder, 10, master cylinder oil inlet, 11, master cylinder oil outlet, 12, input push rod, 13, pedal simulation unit, 14, system Dynamic control system ECU, 15, brushless motor, 16, auxiliary cylinder oil inlet, 17, auxiliary cylinder, 18, auxiliary cylinder oil outlet, 19, ABS input valve port, 20, ABS output valve port, 21, ABS system Move hard pipe.

Detailed ways

The present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

As shown in Figure 1 and Figure 2, the specific implementation includes integrated IBS "Integrated Braking System" designed by-wire power assistance system and integrated in-wheel motor and ABS anti-lock braking system electro-hydraulic coupling brake system, the power-by-wire system includes pedal execution Unit 1 and pressure building unit 2. The electro-hydraulic coupling brake system includes ABS anti-lock brake system 3, hydraulic brake (drum or disc brake), hub motor drive system and hydraulic brake integrated in the hub motor drive system;

As shown in Figure 3, the pedal execution unit 1 includes a brake fluid oil pot 7, a master cylinder 9 and an input push rod 12. The brake fluid oil pot 7 is placed on the top surface of the master cylinder 9, and the pedal simulation unit 13 is placed on the master cylinder 9. On the bottom surface, the brake pedal 4 is connected to one end of the input push rod 12. A displacement sensor for detecting the displacement of the input push rod 12 is installed near the input push rod 12. The other end of the input push rod 12 is installed in the master cylinder 9 and the input push rod There is a gap between the other end of the rod 12 and one end of the piston push rod in the master cylinder 9 to form a first oil chamber. A pressure sensor is installed inside the master cylinder 9, and the second oil chamber at the output end of the piston push rod in the master cylinder 9 is connected to The ABS input valve port 19 of the ABS anti-lock brake system 3, and the piston push rod in the master cylinder 9 is the driving action component that performs braking;

As shown in Figure 4, the pressure building unit 2 includes a brake control system ECU14, a brushless motor 15 and a sub-cylinder 17. The displacement sensor and the brake control system ECU14 are connected through a low-voltage wiring harness, and the pressure sensor and the brake control system ECU14 are connected through a low-voltage wiring harness. The brake control system ECU14 and the brushless motor 15 are connected through a low-voltage wiring harness, the output end of the brushless motor 15 is connected to the auxiliary cylinder 17, and the brake control system ECU14 controls the brushless motor 15 to drive the auxiliary cylinder 17 to form the required oil pressure;

As shown in FIG. 5, the ABS anti-lock braking system 3 has two ABS input valve ports 19 and four ABS output valve ports 20.

The bottom of the brake fluid oil pot 7 is provided with an oil outlet 8 of the brake fluid oil pot. The oil outlet 8 of the brake fluid oil pot is connected to the auxiliary cylinder oil inlet of the auxiliary cylinder 17 of the pressure building unit 2 through the brake hose 5 16. The auxiliary cylinder oil outlet 18 of the auxiliary cylinder 17 of the pressure building unit 2 is connected to the main cylinder oil inlet 10 of the master cylinder 9 of the pedal actuator unit 1 through the auxiliary cylinder brake hard pipe 6, and the master cylinder of the pedal actuator unit 1 The oil outlet 11 of the master cylinder of 9 is connected to the ABS input valve port 19 of the ABS anti-lock brake system 3 through the ABS brake pipe 21, and the ABS output valve port 20 is connected to the hydraulic brake of the wheel through the ABS brake pipe 21. The input end of the moving wheel cylinder.

The ABS anti-lock braking system 3 has the function of preventing the wheels from locking up by adjusting the pressure of the wheel cylinder brake fluid.

The pedal execution unit 1 and the pressure building unit 2 of the wire-controlled power assist system are installed in the front cabin of the vehicle. The ABS anti-lock braking system 3 is installed between the brake and the pedal execution unit 1 and the pressure building unit 2 respectively.

The brake pedal 4 is connected to the input push rod 12 of the pedal actuating unit 1, and the input push rod 12 is connected to the pedal simulation unit 13, and the pedal simulation unit 13 performs sensory feedback on the brake pedal 4 stepped on by the driver. The pedal simulation unit 13 is specifically a force feedback mechanism installed on the pedal, which provides a force feedback to the pedal stepped on by the driver, and assists in sensing the depression depth and speed.

The whole system works according to the following methods, and the working process is as follows:

1) When the driver releases the accelerator pedal of the vehicle, the vehicle enters the coasting state. At this time, the motor regenerative energy recovery part of the in-wheel motor drive system does not work, which is similar to coasting in neutral in the traditional driving mode;

2) When the driver steps on the brake pedal 4 of the vehicle, the motor regenerative energy recovery part of the in-wheel motor drive system works, and at the same time provides the corresponding electromagnetic braking force to the whole vehicle:

If the electromagnetic braking force provided by the electromagnetic brake part of the in-wheel motor drive system cannot meet the braking requirements of the whole vehicle, the whole vehicle cannot be braked completely by electromagnetic braking, and hydraulic brake intervention and electromagnetic brake work together to provide braking force. , The brake control system ECU14 runs according to the data signal sent by the in-wheel motor drive system to control the hydraulic brake to supplement the additional required braking force,

Specifically: the brake control system ECU14 calculates the braking force that needs to be supplemented according to the data signal sent by the in-wheel motor drive system to generate a pressure build signal, controls the hydraulic brake to work according to the pressure build signal, and sends the pressure build signal to the pressure build unit 2. The pressure building unit 2 uses the brushless motor 15 to drive the deceleration mechanism to drive the auxiliary cylinder 17 to generate oil pressure. The oil pressure is transmitted to the master cylinder piston of the master cylinder 9 through the auxiliary cylinder brake hard pipe 6 to form a brake pressure. The brake pressure is pressed into each wheel cylinder through the ABS normally open valve, and the brake fluid pushes the piston in the wheel cylinder to contact the friction plate and the brake disc to realize basic hydraulic braking.

In step 2), specifically:

2.1) After the driver’s foot steps on the brake pedal 4, during the normal pressure build-up process of the driver’s shallow step on the brake pedal 4, the displacement sensor detects the displacement of the input push rod 12; the brake control system ECU14 receives the input push The displacement of the rod 12 generates the braking force required by the entire vehicle, which is specifically controlled according to the movement depth and speed of the brake pedal 4 detected by the displacement sensor, and then sends a pressure building signal to the pressure building unit 2, and the pressure building unit 2 The brush motor 15 drives the deceleration mechanism to drive the auxiliary cylinder 17 to generate oil pressure. The oil pressure is transmitted to the master cylinder piston of the master cylinder 9 through the auxiliary cylinder brake pipe 6 to form and build up the brake pressure, and the pressure sensor monitors the master cylinder The brake pressure in 9 is sent to the brake control system ECU14 to determine whether the brake deceleration requirement is reached, and the brake pressure established by the brake control system ECU14 is fed back to the brake control system ECU14 in real time.

In the normal pressure building process of the driver shallowly depressing the brake pedal 4, the input push rod 12 and the piston push rod of the master cylinder 9 are decoupled, and there is no mechanical hard connection.

The pedal simulation unit 13 simulates the brake pedal force and completely replaces the connection of the traditional mechanical pedal and the pressure building unit 2 in function. The whole vehicle directly sends the braking request to the brake control system ECU14, and the ECU controls the pressure building unit 2 to build pressure to realize wire-by-wire control.

2.2) When the pressure building unit 2 fails, the driver will find that shallow stepping on the brake pedal 4 is invalid, and then stepping on the brake pedal 4 deeply. After the driver stepping on the brake pedal 4 deeply, the displacement of the input push rod 12 increases , The input push rod 12 overcomes the gap between the piston push rod of the master cylinder 9 and hardly connects with the piston push rod of the master cylinder 9, and pushes the piston push rod of the master cylinder 9 to establish braking pressure to achieve braking, and then achieve The mechanical backup of the electro-hydraulic brake is now equivalent to the hydraulic brake of the vehicle without assistance.

3) When the driver steps on the brake pedal 4 of the vehicle and the vehicle speed gradually decreases and is less than the preset critical value, the electromagnetic brake first exits, and then the braking force provided by the hydraulic brake is gradually reduced to realize electro-hydraulic coupling braking .

4) When the driver steps on the brake pedal 4 of the vehicle and the vehicle brakes urgently and the wheels lock up, the electromagnetic brake will exit work at this time:

If the wheels are still locked after the electromagnetic brake is out of work, the ABS anti-lock brake system 3 intervenes to reduce the brake fluid pressure of the hydraulic brake through the internal pressure reducing valve, reduce the wheel braking force, and realize the anti-lock function.

The in-wheel motor drive system has the function of motor regeneration energy recovery. The in-wheel motor realizes electromagnetic braking, that is, the function of regenerative energy recovery.

Therefore, the new energy vehicle adopting the system of the present invention replaces the traditional vacuum pump and vacuum booster with the IBS wire-controlled booster system to realize the full decoupling of the brake pedal and the master cylinder push rod and realize the wire-controlled movement.

When the brake pedal is stepped on or a brake request is sent to the brake control system, the pressure building unit drives the deceleration mechanism through the brushless motor to push the master cylinder piston to build system pressure to achieve hydraulic braking.

At the same time, the motor control system and the brake control system are deeply coupled, divided into the following three situations:

When braking occurs, the electromagnetic braking force is first provided by the regenerative energy recovery of the drive hub motor. If the braking demand of the whole vehicle is still not met at this time, the hydraulic brake will supplement the additional braking force required.

When the vehicle braking requirement is reached, the electromagnetic braking is first exited, and then the hydraulic braking force of the hydraulic brake is slowly reduced to realize electro-hydraulic coupling braking.

When emergency braking and wheel lock occurs, the internal pressure of the wheel cylinder of the hydraulic brake (hydraulic braking force) is adjusted by the pressure reducing valve inside the ABS anti-lock braking system, thereby reducing the wheel braking force and realizing the anti-lock braking function.

With the above scheme, the regenerative energy recovery of the drive motor can be maximized, that is, electromagnetic braking is used to achieve vehicle braking, which effectively improves the efficiency of the vehicle system and reduces energy consumption. At the same time, the use of a wire-controlled power assist system can improve the response speed of the braking system, reduce the system pressure build-up time, and improve the stability and safety of the vehicle's handling when the vehicle is braking.

Claims

An electro-hydraulic coupling brake-by-wire system, which is characterized in that it includes an integrated IBS-designed brake-by-wire system and an electro-hydraulic coupling brake system. The brake-by-wire system includes a pedal execution unit (1) and a pressure building unit (2). ), the electro-hydraulic coupling brake system includes the ABS anti-lock brake system (3), hydraulic brakes, the wheel hub motor drive system and the hydraulic brake integrated in the wheel hub motor drive system;

The pedal execution unit (1) includes a brake fluid oil pot (7), a master cylinder (9) and an input push rod (12). The brake pedal (4) is connected to one end of the input push rod (12), and the input push rod ( 12) A displacement sensor for detecting the displacement of the input push rod (12) is installed nearby, the other end of the input push rod (12) is installed in the master cylinder (9), and the other end of the input push rod (12) and the master cylinder (9) There is a gap between one end of the piston push rod inside, a pressure sensor is installed inside the master cylinder (9), and the output end of the master cylinder (9) is connected to the ABS input valve port (19) of the ABS anti-lock braking system (3);

The pressure building unit (2) includes the brake control system ECU (14), the brushless motor (15) and the auxiliary cylinder (17). The displacement sensor and the brake control system ECU (14) are connected through a wiring harness, and the pressure sensor and brake control The system ECU (14) is connected by a wiring harness, the brake control system ECU (14) and the brushless motor (15) are connected by a wiring harness, the output end of the brushless motor (15) is connected with the auxiliary cylinder (17), and the brake control system ECU ( 14) Control the work of the brushless motor (15) to drive the auxiliary cylinder (17) to form the required oil pressure; the brake fluid oiler (7) is provided with a brake fluid oiler outlet (8), and the brake fluid oiler The oil outlet (8) is connected to the auxiliary cylinder oil inlet (16) of the auxiliary cylinder (17) of the pressure building unit (2) through the brake hose (5), and the auxiliary cylinder (17) of the pressure building unit (2) The auxiliary cylinder oil outlet (18) is connected to the main cylinder oil inlet (10) of the master cylinder (9) of the pedal actuator unit (1) through the auxiliary cylinder brake pipe (6), and the pedal actuator unit (1) The master cylinder oil outlet (11) of the master cylinder (9) is connected to the ABS input valve port (19) of the ABS anti-lock brake system (3) through the ABS brake pipe (21), and the ABS output valve port (20) passes through The ABS brake pipe (21) is connected to the brake wheel cylinder input end of the hydraulic brake.
The electro-hydraulic coupling wire-controlled power-assisted braking system according to claim 1, characterized in that:

The pedal execution unit (1) and the pressure building unit (2) of the wire-controlled power assist system are installed in the front engine room of the vehicle.
The electro-hydraulic coupling wire-controlled power-assisted braking system according to claim 1, characterized in that:

The brake pedal (4) is connected with the input push rod (12) of the pedal execution unit (1), and the input push rod (12) is connected with the pedal simulation unit (13), and the pedal simulation unit (13) gives the driver The depressed brake pedal (4) performs sensory feedback.
The electro-hydraulic coupling wire-controlled power-assisted braking system according to claim 1, characterized in that:

The hydraulic brake is installed in the in-wheel motor drive system and works together with the electromagnetic brake part of the motor in the in-wheel motor drive system.
The electro-hydraulic coupling wire-controlled power-assisted braking system according to claim 1, characterized in that:

The displacement sensor is a digital displacement sensor.
An electro-hydraulic coupling braking method for realizing by-wire assist applied to the system of any one of claims 1-5, characterized in that it works according to the following method, and the working process is as follows:

1) When the driver releases the accelerator pedal of the vehicle, the vehicle enters a coasting state. At this time, the motor regenerative energy recovery part of the in-wheel motor drive system does not work;

2) When the driver steps on the brake pedal (4) of the vehicle, the motor regenerative energy recovery part of the in-wheel motor drive system works and at the same time provides electromagnetic braking force to the whole vehicle:

If the electromagnetic braking force provided by the electromagnetic brake part of the in-wheel motor drive system can meet the braking requirements of the whole vehicle, the whole vehicle will be braked completely by electromagnetic braking, and the hydraulic brake will not intervene in the work;

If the electromagnetic braking force provided by the electromagnetic brake part of the in-wheel motor drive system cannot meet the braking requirements of the whole vehicle, the whole vehicle cannot be braked completely by electromagnetic braking. The hydraulic brake intervenes and the electromagnetic brake works together to provide braking force. The brake control system ECU (14) runs and controls the hydraulic brake to supplement the additional required braking force according to the data signal sent by the wheel hub motor drive system;

3) When the driver steps on the brake pedal (4) of the vehicle and the vehicle speed gradually decreases and is less than the preset critical value, first the electromagnetic brake exits the work, and then gradually reduces the braking force provided by the hydraulic brake to achieve electro-hydraulic coupling brake;

4) When the driver steps on the brake pedal (4) of the vehicle and the vehicle brakes urgently and the wheels lock up, the electromagnetic brake will exit work at this time:

If the wheels do not lock up after the electromagnetic brake is out of work, the whole vehicle can be braked by adjusting the brake pressure of the hydraulic brake;

If the wheels are still locked after the electromagnetic brake is retired, the ABS anti-lock brake system (3) will intervene to reduce the brake fluid pressure of the hydraulic brake, reduce the wheel braking force, and realize the anti-lock function.
The electro-hydraulic coupling braking method for realizing by-wire assist according to claim 6, characterized in that: in said step 2), the brake control system ECU (14) runs according to the information sent from the in-wheel motor drive system The data signal controls the hydraulic brake to supplement the additional required braking force, specifically:

2.1) During the normal pressure build-up process of the driver shallowly depressing the brake pedal (4), the displacement sensor detects the displacement of the input push rod (12); the brake control system ECU (14) receives the input push rod (12) The displacement generates the braking force required by the vehicle, and then sends a pressure building signal to the pressure building unit (2). The pressure building unit (2) drives the auxiliary cylinder (17) to generate oil pressure through the brushless motor (15). The force is transmitted to the master cylinder piston of the master cylinder (9) through the auxiliary cylinder brake hard pipe (6) to form and build up the brake pressure, and the pressure sensor monitors the brake pressure in the master cylinder (9) and sends the signal to The brake control system ECU (14) judges whether the braking deceleration requirement is reached, and feeds back the brake pressure established by the brake control system ECU (14) in real time;

2.2) When the pressure building unit (2) fails, after the driver depresses the brake pedal (4) deeply, the moving displacement of the input push rod (12) increases, and the input push rod (12) overcomes the interference with the master cylinder (9) The gap between the piston push rod and the piston push rod of the master cylinder (9) are hard connected to the piston push rod of the master cylinder (9), which pushes the piston push rod of the master cylinder (9) to establish braking pressure, realize braking, and realize the mechanical electro-hydraulic braking. Backup, at this time, is equivalent to the hydraulic brake of the vehicle without assistance.