CN103754210B - A kind of motor-driven EHB - Google Patents

Abstract

An electro-hydraulic brake system driven by a motor, comprising: brake pedal; pedal displacement sensor; secondary master cylinder; pedal simulator pressure sensor; pedal simulator; pedal simulator solenoid valve; push rod; electronically controlled linear motion module , which drives the push rod to move through the motor-driven motion adjustment mechanism, and controls the motor through the displacement signal to realize the linear control of the brake pressure; the brake master cylinder is hydraulically coupled with the vehicle wheel brake after passing through the ABS/ESP module; ABS/ESP The module can not only passively adjust the pressure delivered to the wheel brakes by the master cylinder, but also actively adjust the brake pressure of each wheel. The electronic hydraulic braking system driven by the motor has the characteristics of fast response, precise control of brake fluid pressure, better simulation of the driver's brake pedal feel, and maximum recovery of braking energy. At the same time, the system is designed with dual failure protection modes , with high security and reliability.

Description

An electro-hydraulic braking system driven by a motor

technical field

The invention belongs to the technical field of automobiles, and relates to automobile braking technology, in particular to an electronic hydraulic braking system driven by a motor.

Background technique

There are two trends in the development of automobiles today: electrification and intelligence. The electric vehicle is equipped with a high-power drive motor. When the vehicle decelerates and brakes, the motor's drag is used to reverse the power supply to generate a reverse electromotive force, which turns the motor into a generator for power generation, and converts the kinetic energy of the vehicle into electrical energy storage. into the battery, namely regenerative braking (also known as braking energy recovery). These stored electric energy can greatly increase the driving range of the car, and change the disadvantages of low driving range and large battery size of electric vehicles. Today, when the battery technology is not perfect enough, it can greatly make up for the problems caused by the lack of battery technology. On the other hand is the intelligentization of automobiles. Nowadays, adaptive cruise systems (ACC) and brake assist systems (BAS) are developing rapidly, which can greatly reduce the burden on drivers.

Electrohydraulic (EHB) is a type of brake-by-wire in which the brake pedal has no mechanical connection at all to the hydraulic system. During the braking process, the driver’s braking intention is judged by calculating the displacement and braking force of the brake pedal during each braking, and the hydraulic active power source is adjusted to control and adjust the braking force of the hydraulic system. Power together to complete the braking. The wire control system can also better cooperate with ACC, BAS and other systems.

Toyota, Bosch, TRW and Continental are the first companies to invest in the research of electronic hydraulic braking system. Toyota Corporation of Japan loaded its electro-hydraulic brake system ECB on a domestic hybrid car in 1997. Prius was the first small car to use an electro-hydraulic brake system. Bosch launched a new HAShev system in 2012, and the hydraulic adjustment unit follows the ESP9.0 system. American Tianhe Motors Corporation (TRW) developed SCB (SlipControlBoost) in 2009. Compared with Bosch's HAS system, it integrates the functions of ESC. Continental also introduced the MKC1 electro-hydraulic braking system in 2012.

Most of the current electronic hydraulic braking systems use motors, pumps and high-pressure accumulators as power sources. However, high-pressure accumulators have the risk of nitrogen leakage, and there are still hidden dangers in reliability and safety.

In the electromechanical hydraulic braking system, the motor and the deceleration mechanism are used to replace the high-pressure accumulator and the pump, which can also realize the active control and adjustment of the hydraulic pressure. The signal is transmitted through the control circuit, and the motor drives the mechanical structure to push the master cylinder. There are problems such as safety hazards of high-voltage accumulators. Its simple structure reduces costs, and the reliability and safety of mechanical connections are higher. It is directly controlled by ECU, and it is easy to realize ABS, TCS, ESP, ACC and other functions. This form of electronic hydraulic braking system has a bright future and is an important development direction of the future braking system.

Contents of the invention

The purpose of the present invention is to provide a motor-driven electronic hydraulic braking system, which is used to recover braking energy, improve system response time, accurately control hydraulic braking force, give the driver braking force feedback well, and realize system hydraulic pressure. and active control of pedal effort.

The purpose of the present invention can be achieved through the following technical solutions: a motor-driven electro-hydraulic braking system, comprising: a brake pedal; a pedal displacement sensor for obtaining the displacement signal of the driver depressing the brake pedal; a secondary master cylinder , used for pedal feeling simulation during normal braking, and directly used for braking during failure backup; pedal simulator pressure sensor used for pedal force active control and failure judgment; pedal simulator, used to simulate pedal feeling; pedal simulator electromagnetic The valve is used to actively control the feedback of the pedal force; the push rod is driven by the motor or manpower to push the piston of the master cylinder; the electronically controlled linear motion module drives the push rod to move through the motor-driven worm gear and rack mechanism, and the displacement signal is used to drive the push rod to move. Control the motor to achieve linear control of the brake pressure; the brake master cylinder, which includes three hydraulic chambers, is a chamber added in front of the first chamber of the traditional master cylinder, which is connected to the vehicle wheel brake after passing through the ABS/ESP module Hydraulic coupling; ABS/ESP module, which can not only passively adjust the pressure delivered by the master cylinder to the wheel brakes, but also actively adjust the pressure of the brakes of each wheel. The electronic control unit ECU calculates the total braking force required for this braking according to the pedal displacement signal, and then calculates the regenerative braking force that the vehicle can generate according to the state of the motor and battery. The total braking force minus the regenerative braking force is the system The braking force that needs to be generated is controlled by the electric motor. The electro-hydraulic brake system driven by the motor includes a mechanical backup mode and a hydraulic backup mode.

Preferably, the brake pedal is connected to one end of the push rod of the secondary master cylinder, and the other end of the push rod of the secondary master cylinder is directly opposite to the push rod in the center of the rack. , the master cylinder is pushed by the master cylinder piston which is in constant contact with the push rod.

Preferably, the hydraulic pipeline of the secondary master cylinder has two branches, one of which is connected to the front cavity of the master cylinder through a solenoid valve. Connect to the pedal simulator fluid inlet.

Preferably, the master cylinder has three hydraulic chambers: a front chamber, a first working chamber and a second working chamber. The front chamber of the master cylinder is connected to the liquid storage tank through a solenoid valve, which is a normally closed valve, and it can realize the function of replenishing liquid after being energized and opened; the first and second working chambers are connected to the ABS/ESP module, and the hydraulic pressure of the wheel cylinder is adjusted.

Preferably, the outlet pipeline of the pedal simulator is connected to the liquid storage tank through a solenoid valve, and the solenoid valve is a normally closed valve, which can actively adjust the reaction force of the simulated pedal.

Preferably, the electronically controlled linear motion module includes an electronic control unit ECU, a motor and a linear motion mechanism, and the motor receives an adjustment torque signal sent by the electronic control unit ECU to control the linear motion mechanism.

Preferably, the decoupling valve is closed in the normal working mode to participate in pedal feeling simulation; in the hydraulic backup mode, the system is powered off and the decoupling valve is opened to realize braking. The push rod of the secondary master cylinder pushes the push rod forward after overcoming the idle stroke, thereby pushing the push rod of the master cylinder to realize mechanical backup protection.

Preferably, the electronically controlled linear motion module includes a rotary motor and a transmission mechanism that converts rotary motion into linear motion, and the transmission mechanism includes a worm gear mechanism and a rack and pinion mechanism.

Preferably, the linear motion mechanism in the transmission mechanism of the electronically controlled linear motion module includes the worm gear mechanism and the rack and pinion mechanism. The rack is hollow, and a push rod passes through the middle. There is a certain gap at the right end of the piston of the cylinder, which depends on the maximum regenerative braking force that the motor can generate in order to realize the decoupling of the pedal and the hydraulic brake when only the motor brakes. The right end of the push rod is in contact with the master cylinder piston push rod. When it is in the mechanical backup mode, it overcomes the gap between the push rod and the secondary master cylinder piston, makes rigid contact, and directly pushes the master cylinder piston for braking.

The electro-hydraulic brake system driven by the motor completes the hydraulic backup function through the decoupling valve, and completes the mechanical backup function through the push rod. Under normal operation, the system is powered on, the decoupling valve is closed, and the piston of the secondary master cylinder moves forward for an idle stroke. The displacement of this idle stroke can be calculated according to the maximum regenerative braking force that the motor can generate; in hydraulic backup mode, the system Power off, the decoupling valve opens, the brake fluid in the secondary master cylinder enters the front chamber MC0 of the master cylinder, and pushes the piston of the master cylinder; rod, further pushing the master cylinder piston for braking.

Preferably, through the secondary master cylinder, the pedal simulator, the pressure sensor of the pedal simulator, and the solenoid valve simulate the feeling of the brake pedal, and actively control the pedal force by adjusting the flow of the solenoid valve.

The front chamber of the master cylinder is connected with the secondary master cylinder, and the first working chamber and the second working chamber are respectively connected with the ABS/ESP module through hydraulic pipelines. The push rod pushes the first piston, and after the first working chamber is pressurized, it pushes the second piston to produce the desired linear motion. The brake fluid flows to the ABS/ESP module through the hydraulic pipeline, and then the braking force generated by each wheel cylinder can be adjusted.

The electro-hydraulic braking system driven by the motor provides a fault diagnosis system, and when a certain braking component fails and a fault occurs, the fault information can be transmitted to the electronic control unit.

The motor-driven electronic hydraulic braking system provides a fault alarm system. When the fault diagnosis system diagnoses that the motor-driven hydraulic braking system is faulty, the alarm device is activated to provide an alarm to the driver at the first time.

When the electronically controlled linear motion module fails, the system enters hydraulic backup, all solenoid valves are powered off, and the brake fluid in the secondary master cylinder enters the front chamber of the master cylinder, pushing the first piston of the master cylinder to brake. During mechanical backup, the secondary master cylinder piston push rod pushes the push rod, and the push rod acts on the master cylinder piston. In failback, the brake fluid pressure of the system is provided entirely by the human foot. When the brake pipeline fails, the electronically controlled linear motion module remains intact, the system works normally, and the pipeline leakage is alerted to the driver by the alarm.

Optionally, the electronically controlled linear motion module can be composed of an outsourcing motor and a ball screw mechanism, and the screw is hollow, through which the push rod can pass.

Compared with the existing electronic hydraulic braking system, the electronic hydraulic braking system driven by the motor of the present invention has the following advantages:

1. The motor is used to control the linear motion mechanism, which has fast response speed and precise control of the hydraulic braking force. It cooperates well with the regenerative braking force of the motor and better completes the driver's braking intention.

2. Since the motor can be precisely controlled, the hydraulic braking force can be adjusted in a timely manner according to the regenerative braking force of the motor and the state of the battery, thereby maximizing the recovery of braking energy.

3. The pedal force of the driver can be actively controlled through the outlet hydraulic adjustment of the pedal simulator.

4. There is a pipeline connection between the secondary master cylinder and the front chamber of the master cylinder. When the motor fails, it will enter the hydraulic backup mode. The system is stable, safe, and the brake feels good.

5. The mechanical connection between the brake pedal and the brake master cylinder reduces the risk of system failure. Even if the motor fails and the hydraulic control pipeline leaks oil, a certain hydraulic braking force can still be generated under the action of the push rod, thereby Ensure that the system has high security and reliability.

Description of drawings

FIG. 1 is a schematic diagram of an electro-hydraulic braking system driven by a motor according to an embodiment of the present invention.

Figure 2 is a schematic diagram of the motor-worm gear reduction mechanism.

Figure 3 is a schematic diagram of the linear motion module.

The label in the accompanying drawing indicates:

1—pedal; 2—pedal displacement sensor; 3—pedal push rod; 4—secondary master cylinder; 5—secondary master cylinder piston; 6—worm gear; 7—worm; 8—gear; 9—rack; 10— Push rod; 11—first piston of master cylinder; 12—motor; 13—front cavity of master cylinder; 14—liquid storage tank; 15—first working chamber of master cylinder; 16—second piston of master cylinder; 17—second piston of master cylinder Two working chambers; 18—master cylinder; 19—ABS/ESP; 20—hydration valve; 21—decoupling valve; 22—regulating valve; 23—hydraulic pressure sensor 1; 24—pedal simulator; 25—pedal simulator piston ; 26—hydraulic pressure sensor; 27—electric control unit ECU.

detailed description

As shown in Figure 1, the electronic hydraulic braking system driven by a motor mainly includes a brake pedal 1, a secondary master cylinder 3, a pedal simulator 24, a decoupling valve 21, a motor 12, a worm gear 6, a worm screw 7, and a master cylinder 18 , Pedal displacement sensor 2, hydraulic pressure sensor 26, electromagnetic valve 20,22.

In this embodiment, the electronically controlled linear motion module includes an electronic control unit ECU27, a motor 12, a reduction mechanism (worm gear 6, worm 7), and a linear motion mechanism (gear 8, rack 9). The motor 12 is connected with the electronic control unit ECU27 through the control circuit, and controls the linear motion mechanism according to the motor torque signal transmitted by the electronic control unit. Shown in Fig. 1 is a kind of preferred electric control linear motion module, motor 12 is a rotary motor, the reduction mechanism is a worm gear mechanism, and the linear motion mechanism is a rack and pinion mechanism. The master cylinder 18 includes a front chamber 13, a first piston 11, a first working chamber 15, a second piston 16, and a second working chamber 17. The front chamber 13 is respectively connected to the secondary master cylinder 4 and the liquid storage tank 14 through a solenoid valve. The first working chamber 15 and the second working chamber 17 are separated by the second piston 16, and both have a compensation hole connected to a liquid storage tank. The first working chamber 15 and the second working chamber 17 are respectively connected with the ABS/ESP module 19 through hydraulic pipelines. The ABS/ESP module is then connected to the four wheel brakes via hydraulic lines.

The specific working process of the electro-hydraulic braking system driven by the motor of the present invention is as follows: the driver steps on the brake pedal 1, the fluid replenishment valve 20, the decoupling valve 21, and the regulating valve 22 are powered on, and the pedal displacement sensor 2 obtains the pedal displacement. The driver’s braking intention transmits the collected signal to the electronic control unit 27, and the electronic control unit calculates the magnitude of the regenerative braking force of the driving motor according to the working characteristics of the motor and the working state of the battery, and subtracts the driving force from the total braking force demand. The motor regenerates the braking force to obtain the hydraulic braking force required for this braking, and then the electronic control unit controls the motor 12 to drive the linear motion module through the control circuit, and the linear motion module pushes the first piston 11 connected to the master cylinder push rod, When the first piston blocks the first compensation hole, the first working chamber starts to build up pressure, and then pushes the second piston 16 to move linearly through the spring and the ejector rod. When the second piston blocks the second compensation hole, the second working chamber starts to build up pressure. The brake fluid flows to the ABS/ESP module 19 through the hydraulic pipeline, and then flows to each wheel cylinder to generate braking force.

According to a preferred embodiment of the present invention, the electronically controlled linear motion module includes a rotary motor 12, a worm gear reduction mechanism and a rack and pinion mechanism that converts rotary motion into linear motion, and the worm 7 is fixedly connected to the rotating shaft of the rotary motor 12. The rotation of the motor drives the worm gear to rotate, thereby driving the coaxial gear to rotate, and the gear drives the rack to change the rotation into a linear motion and push the push rod to move. According to a preferred embodiment of the present invention, the above-mentioned linear motion module may also be composed of a motor and a ball screw mechanism or a lead screw-nut mechanism.

According to the national regulations, the braking system must consider that when failure occurs and certain braking components fail, the system can still perform braking with a certain intensity. The electro-hydraulic braking system driven by the motor of the present invention also includes a fail-safe solution.

When braking starts or is in progress, the motor 12 cannot provide torque or the linear motion mechanism is damaged so that the movement cannot be transmitted. The fault diagnosis system diagnoses the fault information and transmits it to the electronic control unit 27. The electronic control unit immediately powers off the entire system and decouples it. After the valve 21 is powered off, the secondary master cylinder is connected to the front chamber of the master cylinder, and after the replenishment valve 20 is powered off, the pipeline between the front chamber and the liquid storage tank is closed. At this time, step on the pedal again, the brake fluid in the secondary master cylinder 4 enters the front cavity 13 of the master cylinder for braking, and further step on the pedal, the piston 5 of the secondary master cylinder contacts the push rod 10, pushing the first piston 11 of the master cylinder brake.

At present, some electric vehicles are still equipped with a vacuum booster, and a motor is used to drive a vacuum pump to make the vacuum booster generate a certain degree of vacuum. In some emergency braking or continuous braking conditions, the vacuum pump has a long response time, which greatly reduces the braking efficiency. The invention adopts the motor to drive the master cylinder, which has fast response and precise adjustment of hydraulic braking force, which well overcomes the stability of braking efficiency under emergency braking conditions or continuous braking conditions, and at the same time, according to the characteristics of the motor and the state of the battery Adjust hydraulic braking force.

The motor-driven electronic hydraulic braking system of the present invention can also be applied to new energy vehicles, with the goal of maximizing the braking energy recovery of the driving motor, and adjusting the output torque of the motor through the electronic control unit, so that regenerative braking and hydraulic pressure The brakes together form the total braking force.

The above description of the embodiments is for those of ordinary skill in the art to understand and apply the present invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described here to other embodiments without creative efforts. Therefore, the present invention is not limited to the embodiments herein. Improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims (9)

1. A motor-driven electro-hydraulic braking system, characterized in that: comprising: brake pedal; A pedal displacement sensor used to obtain the displacement of the driver's brake pedal; The secondary master cylinder is used for pedal feeling simulation during normal braking, and is directly used for braking when the backup fails; Pedal simulator pressure sensor for active pedal force control and failure judgment; Wire-controlled solenoid valve for active control of pedal force; Pedal simulator for simulating pedal brake feel; A switch valve for realizing the decoupling of the brake pedal and the brake circuit, and hydraulic failure backup; The on-off valve used to realize the liquid replenishment function of the front chamber of the master cylinder; A push rod for pushing the master cylinder piston; Electronically controlled linear motion module, which converts the rotational motion of the motor into the linear motion of the push rod through the mechanical mechanism, and controls the motor through the displacement signal, so as to realize the linear control of the brake pressure; Brake master cylinder, which includes three hydraulic chambers, one chamber is added in front of the first chamber of the traditional master cylinder, and the brake master cylinder is hydraulically coupled with the vehicle wheel brake through the ABS/ESP module; The added chamber is the front chamber of the main cylinder, which is respectively connected with the secondary master cylinder and the liquid storage tank through hydraulic pipelines, and there is a solenoid valve on the two pipelines; the solenoid valve connected with the secondary master cylinder is in the system The decoupling of the pedal and the brake circuit is completed during normal operation. When the system fails, the front chamber of the master cylinder and the secondary master cylinder are connected to realize hydraulic backup; The function of replenishing fluid plays the role of sealing the secondary master cylinder when the system fails; ABS/ESP module, that is, the anti-lock braking system/electronic stability control system module of the vehicle, which can passively and actively adjust the hydraulic braking force of each wheel cylinder; The electronic control unit ECU calculates the total braking force required for this braking according to the pedal displacement signal, and then calculates the regenerative braking force that the vehicle can generate according to the state of the motor and battery. After subtracting the regenerative braking force from the total braking force, the electronic The hydraulic braking system needs to generate the braking force, which is controlled by the electric motor. 2. The electro-hydraulic braking system driven by a motor according to claim 1, wherein the pedal simulator pressure sensor is arranged on the brake pipeline between the secondary master cylinder and the pedal simulator , to measure the hydraulic pressure of the brake line for the identification of the braking intention and the simulated feedback control of the pedal feeling; Adjust the effect of damping, and complete the simulation of pedal feel together with the spring in the pedal simulator. 3. The electro-hydraulic braking system driven by a motor according to claim 2, characterized in that: the electronically controlled linear motion module includes a rotating motor and a transmission mechanism that converts rotary motion into linear motion, and the transmission mechanism includes a worm gear mechanism , rack and pinion mechanism or ball screw; the rack or lead screw is hollow, the push rod passes through its center, and the gap fits; the right end surface of the rack is in contact with the protrusion in the middle of the push rod, and the push rod is driven during normal braking sports. 4. The electro-hydraulic braking system driven by a motor according to claim 3, characterized in that: the linear motion mechanism in the transmission mechanism of the electronically controlled linear motion module includes the push rod, the left end of which is connected to the secondary There is a gap between the right end of the piston of the master cylinder to achieve braking energy recovery, and the right end is in contact with the piston of the master cylinder; in mechanical backup mode, the driver depresses the brake pedal to overcome the gap between the push rod and the piston of the secondary master cylinder , rigid contact, directly pushes the master cylinder piston to brake. 5. The electro-hydraulic braking system driven by a motor according to claim 1, wherein the brake pedal is connected to one end of the push rod of the secondary master cylinder, and the other end of the push rod of the secondary master cylinder is connected to the push rod in the center of the rack Face to face, there is a gap in the middle, after overcoming the gap, the two contact, the braking force can be transmitted, and the master cylinder is pushed by the master cylinder piston which is in constant contact with the push rod; Or the hydraulic pipeline of the secondary master cylinder has two branches, one of which is connected with the front cavity of the master cylinder through a solenoid valve, the solenoid valve is a normally open valve, the brake fluid can enter the front cavity of the master cylinder when it is opened, and the other is connected with the pedal The liquid inlet of the simulator is connected; Or the master cylinder includes three hydraulic chambers: the front chamber, the first working chamber and the second working chamber; the front chamber of the master cylinder is connected to the liquid storage tank through a solenoid valve, which is a normally closed valve, which realizes liquid replenishment after being powered on. Function: the first and second working chambers are connected with the ABS/ESP module, and the hydraulic pressure of the wheel cylinder is adjusted. 6. The electro-hydraulic braking system driven by a motor according to claim 1, characterized in that: the outlet pipeline of the pedal simulator is connected to the liquid storage tank through a solenoid valve, and the solenoid valve is a normally closed valve, which can actively adjust the simulated pedal reaction force; Or the electronically controlled linear motion module includes an electronic control unit ECU, a motor and a linear motion mechanism, and the motor receives an adjustment torque signal sent by the electronic control unit ECU to control the linear motion mechanism; The decoupling valve is closed in the normal working mode and participates in the pedal feeling simulation; in the hydraulic backup mode, the system is powered off and the decoupling valve is opened to realize braking; the push rod of the secondary master cylinder pushes the push rod forward after overcoming the idle stroke , so as to push the master cylinder push rod to realize mechanical backup protection; Or the electronically controlled linear motion module includes a rotary motor and a transmission mechanism that converts rotary motion into linear motion; the linear motion mechanism in the transmission mechanism of the electronically controlled linear motion module includes a worm gear mechanism and a rack and pinion mechanism, and the rack is hollow Yes, there is a push rod passing through the middle, and there is a gap between the left end of the push rod and the right end of the piston of the secondary master cylinder. In order to realize the decoupling of the pedal and the hydraulic brake when only the motor brakes, the gap depends on the maximum regenerative braking that the motor can generate. Power; the right end of the push rod is in contact with the piston push rod of the master cylinder; when in mechanical backup mode, it overcomes the gap between the push rod and the piston of the secondary master cylinder, rigidly contacts, and directly pushes the piston of the master cylinder to brake; Or the electro-hydraulic brake system driven by the motor completes the hydraulic backup function through the decoupling valve, and completes the mechanical backup function through the push rod; under normal operation, when the system is powered on, the decoupling valve is closed, and the piston of the secondary master cylinder moves forward An idle stroke, the displacement of this idle stroke can be calculated according to the maximum regenerative braking force that the motor can generate; in the hydraulic backup mode, the system is powered off, the decoupling valve is opened, and the brake fluid in the secondary master cylinder enters the front of the master cylinder Cavity MC0 pushes the master cylinder piston; in the mechanical backup mode, the secondary master cylinder piston contacts the push rod after overcoming the idle stroke, pushes the push rod, and further pushes the master cylinder piston for braking. 7. The electronic hydraulic braking system driven by a motor according to claim 1, characterized in that: through the secondary master cylinder, the pedal simulator, the pressure sensor of the pedal simulator, and the solenoid valve to simulate the feeling of the brake pedal, by adjusting the solenoid valve Active control of the pedal force by the flow rate; Or the front chamber of the master cylinder is connected with the secondary master cylinder, the first working chamber and the second working chamber are respectively connected with the ABS/ESP module through hydraulic pipelines; the push rod pushes the first piston, and the first working chamber pushes the second The piston produces the desired linear movement, and the brake fluid flows through the hydraulic line to the ABS/ESP module, which in turn can adjust the braking force generated by each wheel cylinder. 8. The electro-hydraulic braking system driven by a motor according to claim 1, characterized in that: It also includes a fault diagnosis system, which can transmit the fault information to the electronic control unit when a brake component fails and fails; Or it also includes a fault alarm system. When the fault diagnosis system diagnoses a fault in the motor-driven hydraulic braking system, the alarm device is activated to provide an alarm to the driver at the first time; Or when the electronically controlled linear motion module fails, the system enters hydraulic backup, all solenoid valves are powered off, and the brake fluid in the secondary master cylinder enters the front chamber of the master cylinder, pushing the first piston of the master cylinder to brake; in mechanical backup, the secondary The push rod of the master cylinder piston pushes the push rod, and the push rod acts on the piston of the master cylinder; when the backup fails, the brake fluid pressure of the system is completely provided by the human foot; when the brake pipeline fails, the electronically controlled linear motion module remains intact , the system works normally, and the pipeline leakage is reminded by the alarm to the driver. 9. The electro-hydraulic braking system driven by a motor according to claim 1, wherein the electronically controlled linear motion module is composed of an outsourced motor and a ball screw mechanism, and the screw is hollow through which the push rod can pass.