WO2022116078A1

WO2022116078A1 - Hydraulic regulation unit, brake-by-wire system and control method

Info

Publication number: WO2022116078A1
Application number: PCT/CN2020/133546
Authority: WO
Inventors: 刘栋豪; 罗杰; 杨维妙; 靳彪; 张永生
Original assignee: 华为技术有限公司
Priority date: 2020-12-03
Filing date: 2020-12-03
Publication date: 2022-06-09
Also published as: CN112638730A

Abstract

Provided are a hydraulic regulation unit, a brake-by-wire system and a control method. The hydraulic regulation unit comprises a first hydraulic regulation device, which comprises a first hydraulic cylinder, a first piston, a second piston, a first spring and a second spring, wherein a first cavity is formed by the first piston, the second piston and the cylinder wall of the first hydraulic cylinder, a second cavity is formed by the second piston and the cylinder wall of the first hydraulic cylinder, the first cavity is connected to a first hydraulic pipeline, the second cavity is connected to a second hydraulic pipeline, the first hydraulic pipeline is used for providing a braking force for a first group of wheel cylinders, and the second hydraulic pipeline is used for providing a braking force for a second group of wheel cylinders; and a second hydraulic regulation device, which comprises a second hydraulic cylinder, a third piston and a third spring, wherein a third cavity is formed by the third piston and the cylinder wall of the second hydraulic cylinder, the third cavity is connected to the first hydraulic pipeline by means of a first electromagnetic valve, and the third cavity is connected to the second hydraulic pipeline by means of a second electromagnetic valve.

Description

Hydraulic adjustment unit, brake-by-wire system and control method

technical field

The present application relates to the field of automobiles, and more particularly, to a hydraulic adjustment unit, a brake-by-wire system and a control method.

Background technique

With the development of automobile electrification and intelligence, automobiles have higher and higher requirements for braking systems. On the one hand, due to the realization of braking energy recovery and active braking functions, it is necessary to decouple the mechanical brake from the driver's brake pedal, that is, brake-by-wire; Safety requirements are also gradually increasing, so the braking system should also have a redundant function, even if one or more components of the braking system fail, the vehicle still has the braking function. In addition to the brake-by-wire and redundant functions, the braking system should also have functions to support chassis stability control, such as implementing electronic stability control system (ESC), antilock brake system (antilock brake system) , ABS), traction control system (traction control system, TCS) and other control functions. As autonomous driving technology has higher and higher requirements for braking systems, there is an urgent need for a braking system that can take into account both the brake-by-wire and redundant functions, while supporting the control functions of various vehicle control systems, so as to meet the needs of autonomous vehicles. control and security needs.

SUMMARY OF THE INVENTION

The present application provides a hydraulic adjustment unit, a brake-by-wire system and a control method, which can satisfy the functions of brake-by-wire and redundant braking and improve driving safety.

In a first aspect, a hydraulic adjustment unit is provided, the hydraulic adjustment unit includes: a first hydraulic adjustment device, the first hydraulic adjustment device includes a first hydraulic cylinder, a first piston, a second piston, a first spring and a second spring, The first piston, the second piston and the cylinder wall of the first hydraulic cylinder form a first cavity, the second piston and the cylinder wall of the first hydraulic cylinder form a second cavity, the first spring connects the first piston and the second piston, the second The spring connects the second piston and the cylinder wall of the first hydraulic cylinder, the first cavity is connected with the first hydraulic pipeline, the second cavity is connected with the second hydraulic pipeline, and the first hydraulic pipeline is used to provide the first group of wheel cylinders Braking force, the second hydraulic pipeline is used to provide braking force for the second group of wheel cylinders; the second hydraulic adjustment device, the second hydraulic adjustment device includes a second hydraulic cylinder, a third piston and a third spring, the third piston and the first The cylinder walls of the three hydraulic cylinders form a third cavity, the third spring connects the third piston and the cylinder wall of the third hydraulic cylinder, the third cavity is connected with the first hydraulic pipeline through the first solenoid valve, and the third cavity is connected with the second solenoid valve. The valve is connected to the second hydraulic line.

The hydraulic adjustment unit of the embodiment of the present application can realize the function of redundant braking. When the first hydraulic adjustment device fails, the second hydraulic adjustment device can provide assistance to realize braking, thereby reducing the burden on the driver and ensuring driving safety.

In combination with the first aspect, in some implementations of the first aspect, the first hydraulic adjustment device further includes a first motor and a first push rod, and the first push rod is connected to the first motor and the first piston. The second hydraulic adjustment device further includes a second motor and a second push rod, and the second push rod is connected to the second motor and the third piston.

With reference to the first aspect, in some implementations of the first aspect, the first hydraulic pipeline is used to provide braking force to the first group of wheel cylinders, and the second hydraulic pipeline is used to provide braking force to the second group of wheel cylinders, It includes: the first motor pushes the first piston through the first push rod to compress the first cavity to adjust the brake fluid in the first hydraulic pipeline, so as to provide braking force for the first group of wheel cylinders; the first piston pushes the second through the first spring The piston compresses the second chamber to adjust the brake fluid in the second hydraulic pipeline to provide braking force for the second group of wheel cylinders.

With reference to the first aspect, in some implementations of the first aspect, the first hydraulic pipeline is used to provide braking force to the first group of wheel cylinders, and the second hydraulic pipeline is used to provide braking force to the second group of wheel cylinders, Including: the first solenoid valve is opened, the second motor pushes the third piston through the second push rod to compress the third cavity to adjust the brake fluid in the first hydraulic pipeline, and provides braking force for the first group of wheel cylinders; the second solenoid valve When it is turned on, the second motor pushes the third piston through the second push rod to compress the third chamber to adjust the brake fluid in the second hydraulic pipeline to provide braking force for the second group of wheel cylinders.

The hydraulic adjustment unit of the embodiment of the present application can implement three different braking modes, including that in general, only the first hydraulic adjustment device can provide the braking force; when the first hydraulic adjustment device and the second hydraulic adjustment device simultaneously provide the braking force When the power is used, braking can be realized more quickly and easily; when the first hydraulic adjustment device is not working, the braking force can also be provided by the second hydraulic adjustment device to ensure driving safety.

In a second aspect, a brake-by-wire system is provided, the brake-by-wire system comprising a master cylinder, a brake input device, a pedal feel simulation device, a first group of wheel cylinders, a second group of wheel cylinders, and the first aspect and the first In the hydraulic adjustment unit of any one of the implementations of the aspect, the brake input device is used to receive a driver's brake command and transmit the brake command to a pedal feel simulation device through the master cylinder, and the pedal feel simulation device is used to feedback the pedal to the driver. Feeling information, the hydraulic adjustment unit provides braking force for the first group of wheel cylinders and the second group of wheel cylinders by adjusting the brake fluid in the first hydraulic line and the second hydraulic line.

With reference to the second aspect, in some implementations of the second aspect, the brake-by-wire system further includes a controller, the controller is configured to calculate a target braking force according to the braking command received by the braking input device, and control the hydraulic pressure according to the target braking force The adjustment unit adjusts the brake fluid in the first hydraulic line and the second hydraulic line.

In addition to the redundant braking function, the brake-by-wire system of the embodiment of the present application can also realize the brake-by-wire function. The brake demand of the driver is measured by the pedal travel sensor, and then fed back to the motor, and the booster device provides assistance to avoid driving. It reduces the driver's burden by decelerating as much as the operator's foot steps on, and at the same time, the pedal feel simulator provides the driver with feedback information on the pedal feel, so that the driver has a good operating feeling and improves the stability, comfort and safety of braking. sex.

In a third aspect, a method for controlling a brake-by-wire system is provided, wherein the brake-by-wire system includes: a first hydraulic adjustment device, and the first hydraulic adjustment device includes a first hydraulic cylinder, a first piston, and a second piston , a first spring and a second spring, the first piston, the second piston and the cylinder wall of the first hydraulic cylinder form a first cavity, the second piston and the cylinder wall of the first hydraulic cylinder form a second cavity, and the first spring is connected to the first A piston and a second piston, a second spring connects the second piston and the cylinder wall of the first hydraulic cylinder, the first chamber is connected to the first hydraulic pipeline, the second chamber is connected to the second hydraulic pipeline, and the first hydraulic pipeline It is used to provide braking force for the first group of wheel cylinders, and the second hydraulic pipeline is used to provide braking force for the second group of wheel cylinders; the second hydraulic adjustment device includes a second hydraulic cylinder, a third piston and The third spring, the third piston and the cylinder wall of the third hydraulic cylinder form a third cavity, the third spring connects the third piston and the cylinder wall of the third hydraulic cylinder, and the third cavity is connected to the first hydraulic pipeline through the first solenoid valve connection, the third chamber is connected with the second hydraulic pipeline through the second solenoid valve,

The control method includes: the first hydraulic adjustment device and/or the second hydraulic adjustment device receive a control command sent by the controller; the first hydraulic adjustment device and/or the second hydraulic adjustment device are the first group of wheel cylinders and the second The wheel cylinders provide braking power.

With reference to the third aspect, in some implementations of the third aspect, the first hydraulic adjustment device further includes a first motor and a first push rod, and the first push rod is connected to the first motor and the first piston. The second hydraulic adjustment device further includes a second motor and a second push rod, and the second push rod is connected to the second motor and the third piston.

With reference to the third aspect, in some implementations of the third aspect, the first hydraulic adjustment device and/or the second hydraulic adjustment device provides braking force for the first group of wheel cylinders and the second group of wheel cylinders according to the control command, including: The first motor pushes the first piston through the first push rod to compress the first cavity to adjust the brake fluid in the first hydraulic pipeline, and provides braking force for the first group of wheel cylinders; the first piston pushes the second piston to compress through the first spring The second chamber adjusts the brake fluid in the second hydraulic pipeline to provide braking force for the second group of wheel cylinders.

With reference to the third aspect, in some implementations of the third aspect, the first hydraulic adjustment device and/or the second hydraulic adjustment device provides braking force for the first group of wheel cylinders and the second group of wheel cylinders according to the control command, including: The first solenoid valve is opened, and the second motor pushes the third piston through the second push rod to compress the third chamber to adjust the brake fluid in the first hydraulic pipeline to provide braking force for the first group of wheel cylinders; the second solenoid valve is opened, The second motor pushes the third piston through the second push rod to compress the third chamber to adjust the brake fluid in the second hydraulic pipeline to provide braking force for the second group of wheel cylinders.

In a fourth aspect, a controller is provided, and the controller may be an independent device or a chip in the device. The controller may include a processing unit and a sending unit. When the controller is an independent device, the processing unit may be a processor, and the sending unit may be an input/output interface; the device may further include a storage unit, which may be a memory; the The storage unit is used for storing instructions, and the processing unit executes the instructions stored in the storage unit, so that the device executes the method in any one of the implementation manners of the third aspect. When the controller is a chip in the device, the processing unit may be a processor, and the sending unit may be a pin or a circuit, etc.; the processing unit executes the instructions stored in the storage unit, so that the control The controller executes the method in any one of the implementation manners of the third aspect, and the storage unit may be a storage unit (for example, a register, a cache, etc.) in the chip, or a storage unit located in the terminal device/network device. A storage unit (eg, read only memory, random access memory, etc.) external to the chip.

In the above-mentioned fourth aspect, the memory is coupled to the processor, and it can be understood that the memory is located inside the processor, or the memory is located outside the processor, so as to be independent of the processor.

In a fifth aspect, a computer program product is provided, the computer program product comprising: computer program code, when the computer program code is run on a computer, causing the computer to execute any one of the implementations of the third aspect above. method.

It should be noted that the above computer program code may be stored in whole or in part on the first storage medium, where the first storage medium may be packaged with the processor or separately packaged with the processor, which is not implemented in this embodiment of the present application. Specific restrictions.

In a sixth aspect, a computer-readable medium is provided, and the computer-readable medium stores program codes that, when the computer program codes are run on a computer, cause the computer to execute any one of the implementations of the third aspect above. Methods.

Description of drawings

Fig. 1 is a schematic block diagram of the hydraulic adjustment unit of the present application;

2 is a schematic block diagram of the brake-by-wire system of the present application;

FIG. 3 is a schematic block diagram of the boosting process in the main boost mode of the brake-by-wire system of the present application;

4 is a schematic block diagram of the decompression process in the main boost mode of the brake-by-wire system of the present application;

FIG. 5 is a schematic block diagram of a quick boost mode boosting process of the brake-by-wire system of the present application;

6 is a schematic block diagram of a decompression process in a rapid boost mode of the brake-by-wire system of the present application;

FIG. 7 is a schematic block diagram of a redundant boost mode boosting process of the brake-by-wire system of the present application;

FIG. 8 is a schematic block diagram of a redundant boost mode decompression process of the brake-by-wire system of the present application;

9 is a schematic flowchart of a control method of the brake-by-wire system of the present application;

10 is a schematic block diagram of the control method of the brake-by-wire system of the present application;

11 is a schematic block diagram of the control device of the present application;

FIG. 12 is a schematic block diagram of the controller of the present application.

Detailed ways

The technical solutions in the present application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

For ease of understanding, related terms and concepts that may be involved in the embodiments of the present application are first introduced below.

Antilock Brake System (ABS): When the car brakes, it automatically controls the size of the braking force, so that the wheels are not locked, in a state of rolling and slipping, so as to ensure that the adhesion between the wheels and the ground is at maximum value.

Traction control system (TCS): a control system that automatically controls the engine and brakes to suppress the rotational speed of the driving wheels when the driving wheels slip when the vehicle is driving.

The electronic stability control system (ESC) sensor collects vehicle information to judge the instability of the vehicle. When the vehicle tends to be unstable, the ESC system applies braking force to a single or part of the wheels to obtain the lateral stability of the wheels. Swing moment, so as to achieve the purpose of stabilizing the vehicle.

Automatic emergency braking (AEB): When the vehicle encounters a sudden dangerous situation or the distance between the vehicle in front and the pedestrian is less than a safe distance, it actively brakes to avoid or reduce the occurrence of collision accidents such as rear-end collisions.

Electro-hydraulic brake system (EHB): It is an advanced mechatronic system, which is developed on the basis of traditional hydraulic brakes, and replaces some mechanical components with electronic and electrical components to achieve the purpose of automatic brake control. .

Adaptive cruise control (ACC): During the driving process of the vehicle, when the distance between the vehicle and the vehicle in front is too small, the braking system brakes the wheels appropriately to keep the wheels at a safe distance from the vehicle in front.

In the prior art, the electromechanical servo booster mechanism iBooster plus ESC scheme is generally used to satisfy the brake-by-wire and redundant functions. iBooster is an electromechanical servo booster mechanism that does not rely on a vacuum source, which can provide conventional braking for automatic driving. The active boost function of ESC provides redundancy for automatic driving braking. Among the two braking systems, if one of the two braking systems If one set fails, the other set of braking systems can still allow the self-driving vehicle to brake and slow down safely without driver intervention. For example, in an existing braking system for an autonomous vehicle, the brake booster is mainly realized by the iBooster, and the brake decoupling is realized by a combination of an electronic supercharger and a solenoid valve. In autonomous driving braking, the controller of the vehicle's braking system can analyze environmental conditions or sensor data input by the driver, and use the iBooster or electronic booster to apply active braking without requiring the driver to operate the brake pedal. iBooster and electronic supercharger are redundant with each other, when one method fails, it can switch to another method for active braking at any time. However, the structure of iBooster is complex. The above braking system requires two sets of hardware braking systems and control systems. The two sets of hardware braking systems work independently, and the coupling control is limited, so the optimization of the system cannot be achieved. In addition, when the iBooster fails, there is no other The device provides braking assistance, and the driver's braking experience is poor.

Another existing braking system adds a dual-chamber electric cylinder to assist the braking on the basis of the traditional non-assist braking system and ESC, so as to realize the functions of brake-by-wire and redundant braking. Among them, the series double-chamber master cylinder is used to form an active booster device, which has mechanical redundancy for pipeline failure, and a plunger pump is used to realize the redundancy of the booster function for the two circuits. However, when this type of braking system performs redundant braking, due to the defects of the plunger pump itself, the pressure build-up rate is limited, and the pressure fluctuation is large and inaccurate, so it is not suitable for functional requirements such as AEB.

With the further development of autonomous driving and new energy technologies, the problems faced by the current braking system include that it is unable to take into account the brake-by-wire and redundant functions at the same time, and it is difficult to meet the control and safety requirements of the vehicle. In addition, the braking system must also Support ABS, AEB, TCS, ESC and other functions, further increasing the complexity of the braking system. Therefore, the embodiments of the present application provide a brake-by-wire system with multiple redundant functions, which can satisfy the brake-by-wire and redundant functions at the same time, and is used to support the control requirements of a new energy vehicle or an autonomous vehicle.

FIG. 1 shows a schematic block diagram of a hydraulic adjustment unit according to an embodiment of the present application, which is used to realize the function of redundant braking. As shown in Figure 1, the hydraulic adjustment unit includes:

The first hydraulic adjustment device 104, the first hydraulic adjustment device 104 includes a first hydraulic cylinder 105, a first piston 19, a second piston 22, a first spring 21 and a second spring 23, the first piston 19, the second piston 22 and The cylinder wall of the first hydraulic cylinder 105 forms the first cavity 20, the second piston 22 and the cylinder wall of the first hydraulic cylinder 105 form the second cavity 24, the first spring 21 connects the first piston 19 and the second piston 22, the second The spring 23 is connected to the second piston 22 and the cylinder wall of the first hydraulic cylinder 105, the first chamber 20 is connected to the first hydraulic pipeline 108, the second chamber 24 is connected to the second hydraulic pipeline 109, and the first hydraulic pipeline 108 is used for In order to provide braking force for the first group of

wheel cylinders

43 and 44, the second hydraulic pipeline 109 is used for providing braking force for the second group of

wheel cylinders

45 and 46;

The second hydraulic adjustment device 106, the second hydraulic adjustment device 106 includes a second hydraulic cylinder 107, a third piston 29 and a third spring 30, the third piston 29 and the cylinder wall of the third hydraulic cylinder 107 form a third cavity 31, the first The three springs 30 are connected to the third piston 29 and the cylinder wall of the third hydraulic cylinder 107 , the third cavity 31 is connected to the first hydraulic pipeline 108 through the first solenoid valve 33 , and the third cavity 31 is connected to the second hydraulic pipeline 108 through the second solenoid valve 34 Hydraulic line 109 is connected.

Optionally, as shown in FIG. 1 , the first hydraulic adjustment device 104 further includes a first motor 17 and a first push rod 18 , and the first push rod 18 is connected to the first motor 17 and the first piston 19 . The second hydraulic adjustment device 106 further includes a second motor 26 and a second push rod 27 , and the second push rod 27 is connected to the second motor 26 and the third piston 29 .

Optionally, the first hydraulic pipeline 108 is used to provide braking force for the first group of

wheel cylinders

43 and 44, and the second hydraulic pipeline 109 is used to provide braking force for the second group of

wheel cylinders

45 and 46, including: a first The motor 17 pushes the first piston 19 through the first push rod 18 to compress the first chamber 20 to adjust the brake fluid in the first hydraulic pipeline 108 to provide braking force for the first group of

wheel cylinders

43 and 44; A spring 21 pushes the second piston 22 to compress the second chamber 24 to adjust the brake fluid in the second hydraulic pipeline 109 to provide braking force for the second group of

wheel cylinders

45 and 46 .

wheel cylinders

45 and 46, including: a first The solenoid valve 33 is opened, and the second motor 26 pushes the third piston 29 through the second push rod 27 to compress the third chamber 31 to adjust the brake fluid in the first hydraulic pipeline 108 to provide braking force for the first group of

wheel cylinders

43 and 44 The second solenoid valve 34 is opened, the second motor 26 pushes the third piston 29 through the second push rod 27 to compress the third chamber 31 to adjust the brake fluid in the second hydraulic pipeline 109, which is the second group of

wheel cylinders

45, 46 provide braking power.

The embodiment of the present application also provides a brake-by-wire system, which can realize the brake-by-wire function and the redundant braking function, including the hydraulic adjustment unit shown in FIG. The device, the first group of wheel cylinders and the second group of wheel cylinders, wherein the brake input device is used to receive the driver's brake command and transmit the brake command to the pedal feel simulation device through the master cylinder, and the pedal feel simulation device is used to send The driver feeds back pedal feeling information, and the hydraulic adjustment unit provides braking force for the first group of wheel cylinders and the second group of wheel cylinders by adjusting the brake fluid in the first hydraulic line and the second hydraulic line.

FIG. 2 shows a schematic block diagram of a brake-by-wire system according to an embodiment of the present application. As shown in FIG. 2, the system mainly includes a master cylinder 101, a mechanical brake input device 102, a pedal feel simulation system 103, and an active booster device 104. The redundant boosting device 106, etc., will be introduced separately below.

The master cylinder 101 is in the form of a series of double chambers, including two pistons 5 and 8 and two return springs 6 and 9 . The piston 5 and the piston 8 are connected by the return spring 6 , and the piston 5 and the piston 8 divide the master cylinder 101 into a cavity 7 and a cavity 10 . The two

chambers

7 and 10 of the master cylinder 101 are provided with brake fluid (hydraulic oil) from the fluid storage device 1, and the

chambers

7 and 10 are respectively connected to one or more wheel cylinders through the hydraulic pipeline 108 and the hydraulic pipeline 109, The pressure sensor 11 of the master cylinder 101 is installed on the output hydraulic pipeline 109 of the master cylinder chamber 10 .

The mechanical brake input device 102 includes a pedal 2 , a push rod 3 and a pedal travel sensor 4 . The push rod 3 connects the piston 5 in the master cylinder 101 with the brake pedal 2 , and the pedal stroke sensor 4 is used to measure the displacement of the push rod 3 relative to the master cylinder 101 .

The pedal feel simulation system 103 includes a pedal feel simulator 12 , a one-way valve 13 and a solenoid valve 14 . The cavity 7 of the master cylinder 101 is connected to the pedal feel simulator 12 through a hydraulic pipeline 108 , a one-way valve 13 and a solenoid valve 14 .

The active booster device 104 is powered by the motor 17 , and the active booster hydraulic cylinder 105 provides a pressure building site. The active boosting hydraulic cylinder 105 includes a piston 19 , a piston 22 , a return spring 20 , and a return spring 23 . The piston 19 and the piston 22 are connected by a return spring 20 , and the piston 19 and the piston 22 divide the interior of the active pressurizing hydraulic cylinder 105 into a cavity 21 and a cavity 24 . The active supercharging motor 17 pushes the piston 19 to move left and right through the transmission mechanism 18 , and the piston 22 also moves left and right under the action of the return spring 20 . Chamber 21 and chamber 24 are connected to one or more wheel cylinders through hydraulic line 108 and hydraulic line 109 respectively, and pressure sensor 25 is mounted on output hydraulic line 109 of chamber 24 .

The redundant pressure boosting device 106 is powered by the motor 26 , and the redundant pressure boosting hydraulic cylinder 107 provides a pressure building site. The redundant boosting hydraulic cylinder 107 includes a piston 29 and a return spring 30 , and the piston 29 divides the hydraulic cylinder into a cavity 28 and a cavity 31 . The motor 26 pushes the piston 29 to move up and down through the transmission device 27 . The cavity 31 is connected to the liquid storage device 1 through the one-way valve 32, and is connected to the hydraulic pipeline 108 and the hydraulic pipeline 109 through the solenoid valve 33 and the solenoid valve 34, respectively.

The hydraulic pipeline 108 obtains the brake fluid from the master cylinder chamber 7, the active booster hydraulic cylinder chamber 21 and the redundant booster hydraulic cylinder chamber 31 respectively, wherein the solenoid valve 15 is used to control the on-off of the brake fluid of the master cylinder 101, and the solenoid The valve 33 is used to control the on-off of the brake fluid of the redundant boosting hydraulic cylinder 107 .

The hydraulic pipeline 109 obtains the brake fluid from the master cylinder chamber 10, the active booster hydraulic cylinder chamber 24 and the redundant booster hydraulic cylinder 31 respectively, wherein the solenoid valve 16 is used to control the on-off of the brake fluid of the master cylinder 101, and the solenoid valve 34 is used to control the on-off of the brake fluid of the redundant booster hydraulic cylinder 107 .

In addition, the brake-by-wire system of the embodiment of the present application further includes a wheel cylinder 43 , a wheel cylinder 44 , a wheel cylinder 45 and a wheel cylinder 46 , which are respectively connected by

oil inlet valves

35 , 36 , 37 , 38 and

oil outlet valves

39 , 40 , and 41 . , 42 control the respective brake pressure.

The brake-by-wire system of the embodiment of the present application further includes a controller (not shown in FIG. 2 ), and the controller is configured to calculate a target braking force according to the braking command received by the braking input device, and control the hydraulic adjustment unit according to the target braking force Adjust the brake fluid in the first hydraulic line and the second hydraulic line. The individual components in the brake-by-wire system can also have their own sub-controllers, and these controllers can communicate with each other and work together. The controller receives detection signals from various sensors, such as environmental conditions, driver input, braking system status, etc., and controls the brake-by-wire system through calculation and judgment.

Three working modes of the brake-by-wire system of the embodiment of the present application are respectively introduced below with reference to FIGS. 3 to 8 : a main boost mode, a rapid boost mode, and a redundant boost mode. With the further development of autonomous driving and new energy technologies, advanced driving assistance systems (ADAS) can use sensors such as cameras, radars, lasers, and ultrasonics to instantly sense and collect surrounding environment data during driving. Identify, detect and track obstacles, and perform braking control on vehicles, such as ACC, AEB and other functions. Active boosting during ADAS operation is similar to the brake-by-wire, core boosting and decompression processes during manual braking. The following takes the brake-by-wire during manual braking as an example to illustrate.

1. Main boost mode

FIG. 3 shows a schematic block diagram of the boosting process in the main boosting mode of the brake-by-wire system according to the embodiment of the present application. When the brake-by-wire system of the embodiment of the present application performs the boosting process in the main boosting mode, the

solenoid valves

15 and 16 are closed, and the solenoid valve 14 is opened to make the pedal feel simulator 12 communicate with the hydraulic pipeline 108 , and the other solenoid valves are kept at their default values. state.

The driver steps on the brake pedal 2, the push rod 3 moves to the left and pushes the piston 5 to compress the return spring 6, and pushes the brake fluid in the cavity 7 into the hydraulic pipeline 108; at the same time, the return spring 6 pushes the piston 8 to compress and return to its original position. The spring 9 pushes the brake fluid in the cavity 10 into the hydraulic line 109 . Since the

solenoid valves

15, 16 are closed, the brake fluid in the hydraulic line 108 will compress the spring in the pedal feel simulator 12 through the solenoid valve 14, and the brake fluid in the hydraulic line 109 will be compressed by the piston 8. Pressure rises.

The pedal travel sensor 4 measures the pedal displacement of the driver, calculates the target braking force required by the driver through the controller, and feeds back the calculated target braking force to the active supercharging device 104 . The active supercharging device 104 controls the motor 17 according to the target braking force, pushes the piston 19 through the transmission mechanism 18 to compress the return spring 20, and pushes the brake fluid in the cavity 21 into the hydraulic pipeline 108; at the same time, the return spring 20 pushes the piston 22 to compress back. The position spring 23 pushes the brake fluid in the cavity 24 into the hydraulic line 109 . Further, the brake fluid flows to each wheel cylinder through the

hydraulic pipes

108, 109 through the

oil inlet valves

35, 36, 37, 38, thereby realizing braking.

FIG. 4 shows a schematic block diagram of the decompression process in the main boost mode of the brake-by-wire system according to the embodiment of the present application. As shown in Figure 4, the driver releases the brake pedal 2, the piston 5 pushes the push rod 3 to move to the right under the action of the return spring 6, the rightward movement of the piston 5 causes a negative pressure in the cavity 7, and the brake fluid is The hydraulic pipeline 108 returns; at the same time, the piston 8 returns under the pulling action of the return spring 6 and the return action of the return spring 9, negative pressure is generated in the cavity 10, and the brake fluid flows back from the hydraulic pipeline 109. 15 , 16 are closed and the spring return in pedal feel simulator 12 forces brake fluid back into hydraulic line 108 .

The pedal travel sensor 4 measures the pedal displacement of the driver, calculates the target braking force required by the driver through the controller, and feeds the target braking force to the active supercharging device 104 . The active supercharging device 104 controls the motor 17 according to the target braking force, pulls the piston 19 to move to the right through the transmission device 18, generates negative pressure in the cavity 21, and the brake fluid in the

wheel cylinders

43, 44 passes through the

oil inlet valves

35, 36 and The hydraulic pipeline 108 returns to the cavity 21; at the same time, the piston 22 moves to the right under the pulling action of the return spring 20 and the return action of the return spring 23, and negative pressure is generated in the cavity 24, and the pistons in the

wheel cylinders

45 and 46 move to the right. The brake fluid is returned to the cavity 24 through the

oil inlet valves

37, 38 and the hydraulic pipeline 109, thereby reducing the braking force.

The brake-by-wire system of the embodiment of the present application can realize pedal decoupling, set

solenoid valves

15, 16 and close the

solenoid valves

15, 16, measure the driver's braking demand through the pedal stroke sensor, and then feed it back to the motor, which is boosted by the booster The device provides power assistance to avoid the situation that the driver decelerates as much as he steps on his feet, reducing the driver's burden; at the same time, the pedal feel simulator provides the driver with feedback information on pedal feeling, so that the driver has a good operating feeling and improves braking stability. sex, comfort and safety. In the main boost mode, the brake boost is provided by the active boost device to achieve braking.

2. Fast boost mode

FIG. 5 shows a schematic block diagram of a supercharging process in a rapid supercharging mode of the brake-by-wire system according to the embodiment of the present application. When the brake-by-wire system of the embodiment of the present application performs the boosting process in the rapid boosting mode, the

solenoid valves

15 and 16 are closed, the solenoid valve 14 is opened so that the pedal feel simulator 12 is communicated with the hydraulic pipeline 108 , and the

solenoid valves

33 and 34 are opened. The redundant boosting device 106 is communicated with the

hydraulic lines

108, 109, and the other solenoid valves are kept in their default states.

solenoid valves

15 and 16 are closed, the brake fluid in the hydraulic line 108 compresses the spring in the pedal feel simulator 12 through the solenoid valve 14 , and the pressure of the brake fluid in the hydraulic line 109 increases under the action of the piston 8 .

The pedal travel sensor 4 measures the pedal displacement of the driver, calculates the target braking force required by the driver through the controller, and feeds the target braking force to the active supercharging device 104 and the redundant supercharging device 106 . The active supercharging device 104 controls the motor 17 according to the target braking force, pushes the piston 19 to compress the return spring 20 through the transmission mechanism 18, and pushes the brake fluid in the cavity 21 into the hydraulic pipeline 108; at the same time, the return spring 20 pushes the piston 22 to compress and return to the original position. The spring 23 pushes the brake fluid in the cavity 24 into the hydraulic line 109 . The redundant booster 106 controls the motor 26 according to the target braking force, pushes the piston 29 through the transmission mechanism 27 to compress the return spring 30, and pushes the brake fluid in the cavity 31 into the

hydraulic pipelines

108, 109 through the

solenoid valves

33, 34 . Further, the brake fluid flows to each wheel cylinder through the

hydraulic pipes

108, 109 through the

oil inlet valves

35, 36, 37, 38, thereby realizing braking. In the rapid boost mode shown in FIG. 4 , rapid boost can be achieved through the combined action of the main motor 17 and the auxiliary motor 26 .

FIG. 6 shows a schematic block diagram of a decompression process in a rapid boost mode of the brake-by-wire system according to an embodiment of the present application. As shown in 6, the driver releases the brake pedal 2, the piston 5 pushes the push rod 3 to move to the right under the action of the return spring 6, the rightward movement of the piston 5 causes a negative pressure in the cavity 7, and the brake fluid is The hydraulic pipeline 108 returns; at the same time, the piston 8 moves to the right under the pulling action of the return spring 6 and the return action of the return spring 9, negative pressure is generated in the cavity 10, and the brake fluid flows back from the hydraulic pipeline 109. With the

solenoid valves

15 , 16 closed, the spring return in the pedal feel simulator 12 returns the brake fluid to the hydraulic line 108 .

The pedal travel sensor 4 measures the pedal displacement of the driver, calculates the target braking force required by the driver through the controller, and feeds back the target braking force to the active supercharging device 104 and the redundant supercharging device 106 . The active supercharging device 104 controls the motor 17 according to the target braking force, and pulls the piston 19 to move to the right through the transmission device 18, negative pressure is generated in the cavity 21, and the brake fluid in the

wheel cylinders

43, 44 passes through the

oil inlet valves

35, 36 and The hydraulic pipeline 108 is returned to the cavity 21; at the same time, the piston 22 is returned under the pulling action of the return spring 20 and the return action of the return spring 23, and negative pressure is generated in the cavity 24, and the brakes in the

wheel cylinders

45 and 46 The liquid returns to the cavity 24 through the

oil inlet valves

37 and 38 and the hydraulic pipeline 109 . The redundant supercharging device 106 controls the motor 26 according to the target braking force, and pulls the piston 29 to move upward through the transmission device 27, negative pressure is generated in the cavity 31, and the brake fluid in the

wheel cylinders

43, 44, 45, 46 passes through the

oil inlet valve

35, 36 , 37 , 38 ,

hydraulic lines

108 , 109 and

solenoid valves

33 , 34 return to chamber 31 . As a result, the braking force is reduced.

In the fast boost mode, both the active booster and the redundant booster provide power assist for faster and easier braking.

3. Redundant boost mode

FIG. 7 shows a schematic block diagram of the supercharging process in the redundant supercharging mode of the brake-by-wire system according to the embodiment of the present application. When the active supercharging device 104 fails, the redundant supercharging mode can be used. When the brake-by-wire system of the embodiment of the present application is in the process of supercharging in the redundant supercharging mode, the

solenoid valves

15 and 16 are closed, and the solenoid valve 14 is opened to make the pedal feel simulator 12 communicate with the hydraulic pipeline 108 , and the

solenoid valves

33 and 34 Open to connect the redundant boosting device 106 with the

hydraulic lines

108, 109, and the other solenoid valves remain in their default states.

solenoid valves

The pedal travel sensor 4 measures the pedal displacement of the driver, calculates the target braking force required by the driver through the controller, and feeds back the target braking force to the redundant supercharging device 106 . The redundant booster 106 controls the motor 26 according to the target braking force, pushes the piston 29 through the transmission mechanism 27 to compress the return spring 30, and pushes the brake fluid in the cavity 31 into the

hydraulic pipelines

108 and 109 through the

solenoid valves

33 and 34 respectively. middle. Further, the brake fluid flows to each wheel cylinder through the

hydraulic pipes

108, 109 through the

oil inlet valves

35, 36, 37, 38, thereby realizing braking.

FIG. 8 shows a schematic block diagram of a decompression process in a redundant boost mode of a brake-by-wire system according to an embodiment of the present application. As shown in 8, the driver releases the brake pedal 2, the piston 5 pushes the push rod 3 to move to the right under the action of the return spring 6, and the rightward movement of the piston 5 causes a negative pressure in the cavity 7, and the brake fluid is The hydraulic pipeline 108 returns; at the same time, the piston 8 moves to the right under the pulling action of the return spring 6 and the return action of the return spring 9, negative pressure is generated in the cavity 10, and the brake fluid flows back from the hydraulic pipeline 109. With the

solenoid valves

The pedal travel sensor 4 measures the pedal displacement of the driver, calculates the target braking force required by the driver through the controller, and feeds back the target braking force to the redundant supercharging device 106 . The redundant supercharging device 106 controls the motor 26 according to the target braking force, and pulls the piston 29 to move upward through the transmission device 27 , negative pressure is generated in the cavity 31 , and the brake fluid in the

wheel cylinders

43 , 44 , 45 and 46 passes through the

oil inlet valve

35 , 36 , 37 , 38 ,

hydraulic lines

108 , 109 and

solenoid valves

33 , 34 return to cavity 31 . As a result, the braking force is reduced.

If the active supercharging device fails, it can be powered by the redundant supercharging device, which can still achieve effective braking and ensure driving safety.

The hydraulic adjustment unit and the brake-by-wire system of the embodiments of the present application are described above with reference to FIGS. 1 to 8 , and the control methods provided by the embodiments of the present application are described below with reference to FIGS. 9 and 10 . It should be understood that the embodiments of the present application provide The solution can be used in conjunction with the above-mentioned hydraulic adjustment unit and the brake-by-wire system, or the method of the present application can also be applied to a braking system including any of the above-mentioned hydraulic adjustment units.

FIG. 9 is a schematic flowchart of a control method of a brake-by-wire system according to an embodiment of the present application. The method shown in FIG. 9 includes step 901 and step 902, which will be introduced separately below.

S901, the first hydraulic adjustment device and/or the second hydraulic adjustment device receive a control instruction sent by a controller.

S902, the first hydraulic adjustment device and/or the second hydraulic adjustment device provide braking force for the first group of wheel cylinders and the second group of wheel cylinders according to the control command.

The brake-by-wire system may be any of the brake-by-wire systems shown in FIGS. 2 to 8 , and may include the hydraulic adjustment unit shown in FIG. 1 . For details, please refer to the above description of the hydraulic adjustment unit and the brake-by-wire system. , for the sake of brevity, the embodiments of the present application will not be repeated here.

Optionally, as an embodiment, the first hydraulic adjustment device provides braking force for the first group of wheel cylinders and the second group of wheel cylinders according to a control command, wherein the control command is used to instruct the

solenoid valves

33 and 34 in FIG. 2 to close and The magnitude of the braking force may specifically be: the first motor pushes the first piston through the first push rod to compress the first cavity according to the control command to adjust the brake fluid in the first hydraulic pipeline, so as to provide braking force for the first group of wheel cylinders; The first piston pushes the second piston through the first spring to compress the second chamber to adjust the brake fluid in the second hydraulic pipeline, so as to provide braking force for the second group of wheel cylinders. At this time, the second hydraulic adjustment device does not work.

Optionally, as an embodiment, when the first hydraulic adjustment device is not working, the control instruction instructs the

solenoid valves

33 and 34 in FIG. 2 to open, and the second hydraulic adjustment device is the first group of wheel cylinders and the second hydraulic adjustment device according to the control instruction. The wheel cylinders provide braking force, which can be specifically: the second motor pushes the third piston through the second push rod to compress the third cavity to adjust the brake fluid in the first hydraulic pipeline, so as to provide braking force for the first group of wheel cylinders; The second motor pushes the third piston through the second push rod to compress the third chamber to adjust the brake fluid in the second hydraulic pipeline to provide braking force for the second group of wheel cylinders.

Optionally, as an embodiment, when the first hydraulic adjustment device provides braking force for the first group of wheel cylinders and the second group of wheel cylinders according to the control command, the

solenoid valves

33 and 34 in FIG. 2 are opened, and the second hydraulic adjustment device The braking force is also provided for the first group of wheel cylinders and the second group of wheel cylinders according to the control command, that is, the first hydraulic adjustment device and the second hydraulic adjustment device work simultaneously.

FIG. 10 shows a schematic block diagram of the control method of the brake-by-wire system according to the embodiment of the present application. As shown in FIG. 10 , the brake-by-wire system according to the embodiment of the present application may have multiple working modes.

Start by choosing between power-assist or brake-by-wire mode, depending on the current braking demand.

The pedal travel sensor obtains the driver's braking intention or the braking intention under ADAS and automatic driving conditions, and calculates the braking pressure and braking speed.

According to the braking pressure and braking speed, the supercharging mode is determined, and the supercharging mode includes the main supercharging mode, the fast supercharging mode and the redundant supercharging mode as described above in FIG. 3 to FIG. 8 .

The state of the monitoring system determines the final boosting mode. Specifically, the state of the system can be monitored through information such as the pressure of the active boosting hydraulic cylinder, the pressure of the redundant boosting hydraulic cylinder, the status of the solenoid valve and the state of the motor. If the system state is good and can support the above-determined boost mode, build pressure according to the above-determined boost mode, adjust the brake fluid in the hydraulic pipeline, so as to realize braking; if the system state cannot support the above-determined boost mode, By default, the primary supercharging mode is selected for pressure build-up; if the active supercharging device fails, the redundant supercharging mode is selected for pressure building; in an extreme case, both the active supercharging device and the redundant supercharging device are In the event of failure, the

solenoid valves

15 and 16 are opened, and the driver manually builds pressure through the pedal.

Determine the target braking force of the electric motor of the first hydraulic adjustment device and/or the second hydraulic adjustment device according to the final boost mode and braking force determined above, and feed the target braking force to the first hydraulic adjustment device and/or the second hydraulic adjustment device. 2. Motor of hydraulic adjustment device.

According to the target braking force and the final boost mode, the motor and the corresponding solenoid valve of the first hydraulic adjustment device and/or the second hydraulic adjustment device are controlled to adjust the brake fluid in the hydraulic pipeline, thereby realizing braking. For the specific pressure building process, reference may be made to the foregoing descriptions of FIGS. 3 to 8 . For brevity, the embodiments of the present application will not be repeated here.

The control method of the brake-by-wire system according to the embodiment of the present application is described above with reference to FIG. 9 and FIG. 10 , and the control device for executing the above control method in the present application is described below with reference to FIG. 11 and FIG. 12 . It should be noted that the devices in the embodiments of the present application can be applied to the hydraulic adjustment unit or the brake-by-wire system described above to implement one or more steps in the control method described above. Repeat.

FIG. 11 is a schematic block diagram of a control apparatus according to an embodiment of the present application. The control apparatus 1100 shown in FIG. 11 includes a processing unit 1110 and a transceiver unit 1220 .

The processing unit 1110 is configured to generate a control instruction, where the control instruction is used to control the first hydraulic adjustment device and/or the second hydraulic adjustment device.

A transceiver unit 1120, configured to send a control command to the first hydraulic adjustment device and/or the second hydraulic adjustment device, the first hydraulic adjustment device and/or the second hydraulic adjustment device are the first group of wheel cylinders and the second group of wheel cylinders according to the control instruction Wheel cylinders provide braking force.

Optionally, as an embodiment, the first hydraulic adjustment device provides braking force for the first group of wheel cylinders and the second group of wheel cylinders according to a control instruction sent by the transceiver unit 1120, where the control instruction is used to instruct the solenoid valve in FIG. 2 . 33 and 34 are closed and the magnitude of the braking force can be specifically: the first motor pushes the first piston through the first push rod to compress the first chamber according to the control command to adjust the brake fluid in the first hydraulic pipeline, which is the first set of wheels. The cylinder provides braking force; the first piston pushes the second piston through the first spring to compress the second chamber to adjust the brake fluid in the second hydraulic pipeline, so as to provide braking force for the second group of wheel cylinders. At this time, the second hydraulic adjustment device does not work.

solenoid valves

33 and 34 in FIG. 2 to open, and the second hydraulic adjustment device is the first group according to the control instruction sent by the transceiver unit 1120. The wheel cylinder and the second group of wheel cylinders provide braking force, which can be specifically: the second motor pushes the third piston through the second push rod to compress the third chamber to adjust the brake fluid in the first hydraulic pipeline, which is the first group of wheel cylinders. Provide braking force; the second motor pushes the third piston through the second push rod to compress the third chamber to adjust the brake fluid in the second hydraulic pipeline, so as to provide braking force for the second group of wheel cylinders.

Optionally, as an embodiment, when the first hydraulic adjustment device provides braking force for the first group of wheel cylinders and the second group of wheel cylinders according to the control command sent by the transceiver unit 1120, the

solenoid valves

33 and 34 in FIG. 2 are opened, The second hydraulic adjustment device also provides braking force for the first group of wheel cylinders and the second group of wheel cylinders according to the control command sent by the transceiver unit 1120 , that is, the first hydraulic adjustment device and the second hydraulic adjustment device work simultaneously.

FIG. 12 is a schematic block diagram of a controller according to an embodiment of the present application. The controller 1200 shown in FIG. 12 may include: a memory 1210 , a processor 1220 , and a communication interface 1230 . The memory 1210, the processor 1220, and the communication interface 1230 are connected through an internal connection path, the memory 1210 is used to store instructions, and the processor 1220 is used to execute the instructions stored in the memory 1220 to control the communication interface 1230 to receive/send information. Optionally, the memory 1210 may be coupled with the processor 1220 through an interface, or may be integrated with the processor 1220 .

It should be noted that the above-mentioned communication interface 1230 uses a device such as but not limited to an input/output interface (input/output interface) to implement communication between the controller 1200 and other devices or a communication network.

In the implementation process, each step of the above-mentioned method may be completed by an integrated logic circuit of hardware in the processor 1220 or an instruction in the form of software. The methods disclosed in conjunction with the embodiments of the present application may be directly embodied as executed by a hardware processor, or executed by a combination of hardware and software modules in the processor. The software modules may be located in random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, registers and other storage media mature in the art. The storage medium is located in the memory 1210, and the processor 1220 reads the information in the memory 1210, and completes the steps of the above method in combination with its hardware. To avoid repetition, detailed description is omitted here.

It should be understood that, in this embodiment of the present application, the processor may be a central processing unit (central processing unit, CPU), and the processor may also be other general-purpose processors, digital signal processors (digital signal processors, DSP), dedicated integrated Circuit (application specific integrated circuit, ASIC), off-the-shelf programmable gate array (field programmable gate array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

It should also be understood that, in this embodiment of the present application, the memory may include a read-only memory and a random access memory, and provide instructions and data to the processor. A portion of the processor may also include non-volatile random access memory. For example, the processor may also store device type information.

When this application introduces the architecture of braking systems, automobiles, etc. in conjunction with the accompanying drawings, the accompanying drawings will schematically show two working states (disconnected or connected) that each control valve can achieve, and do not limit the current state of the control valve. The working status is shown in the figure.

In addition, when this application introduces the structures of hydraulic adjustment units, braking systems, automobiles, etc. in conjunction with the accompanying drawings, the components with the same functions in the drawings corresponding to the various embodiments are numbered the same. For the description in each embodiment, reference may be made to the introduction about the function of each component in the whole text.

In addition, the hydraulic adjustment unit in the present application may be a unit for adjusting the brake hydraulic pressure in the brake system, including one or more brake pipelines (hydraulic pipelines) mentioned above, and the brake pipeline in the brake pipeline. Control valve, check valve and other components. Optionally, the above-mentioned hydraulic adjustment unit may further include components such as hydraulic cylinders, pistons, push rods and the like in the hydraulic adjustment device. After the above-mentioned hydraulic adjustment unit is installed in the braking system, the braking system may include components such as a hydraulic adjustment unit, a brake wheel cylinder, a liquid storage device, and a brake pedal.

Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of this application.

Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described systems, devices and units may refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as independent products, may be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be embodied in the form of a software product in essence, or the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including Several instructions are used to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), magnetic disk or optical disk and other media that can store program codes .

Claims

A hydraulic adjustment unit, characterized in that it includes:

A first hydraulic adjustment device comprising a first hydraulic cylinder, a first piston, a second piston, a first spring and a second spring, the first piston, the second piston and the first A cylinder wall of a hydraulic cylinder forms a first cavity, the second piston and the cylinder wall of the first hydraulic cylinder form a second cavity, the first spring connects the first piston and the second piston, so The second spring is connected to the second piston and the cylinder wall of the first hydraulic cylinder, the first cavity is connected to the first hydraulic pipeline, the second cavity is connected to the second hydraulic pipeline, and the first cavity is connected to the second hydraulic pipeline. A hydraulic pipeline is used to provide braking force to the first group of wheel cylinders, and the second hydraulic pipeline is used to provide braking force to the second group of wheel cylinders;

A second hydraulic adjustment device, the second hydraulic adjustment device includes a second hydraulic cylinder, a third piston and a third spring, the third piston and the cylinder wall of the third hydraulic cylinder form a third cavity, the first Three springs connect the third piston and the cylinder wall of the third hydraulic cylinder, the third cavity is connected to the first hydraulic pipeline through a first solenoid valve, and the third cavity is connected to the first hydraulic pipeline through a second solenoid valve The second hydraulic line is connected.
The hydraulic adjustment unit according to claim 1, wherein the first hydraulic adjustment device further comprises a first motor and a first push rod, and the first push rod is connected to the first motor and the first push rod The second hydraulic adjustment device further includes a second motor and a second push rod, and the second push rod is connected to the second motor and the third piston.
The hydraulic adjustment unit according to claim 2, wherein the first hydraulic pipeline is used to provide braking force for the first group of wheel cylinders, and the second hydraulic pipeline is used to provide the second group of wheel cylinders with braking force Braking force, including:

The first motor pushes the first piston through the first push rod to compress the first cavity to adjust the brake fluid in the first hydraulic pipeline, so as to provide braking force for the first group of wheel cylinders;

The first piston pushes the second piston through the first spring to compress the second chamber to adjust the brake fluid in the second hydraulic pipeline, so as to provide braking force for the second group of wheel cylinders.
The hydraulic adjustment unit according to claim 2 or 3, wherein the first hydraulic pipeline is used for providing braking force for the first group of wheel cylinders, and the second hydraulic pipeline is used for the second group of wheel cylinders Cylinders provide braking power, including:

The first solenoid valve is opened, and the second motor pushes the third piston through the second push rod to compress the third cavity to adjust the brake fluid in the first hydraulic pipeline, so as to provide the first hydraulic pressure. A set of wheel cylinders provide braking force;

The second solenoid valve is opened, and the second motor pushes the third piston through the second push rod to compress the third cavity to adjust the brake fluid in the second hydraulic pipeline, so that the Two sets of wheel cylinders provide braking power.
A brake-by-wire system, characterized in that it comprises a master cylinder, a brake input device, a pedal feel simulation device, a first group of wheel cylinders, a second group of wheel cylinders and the hydraulic pressure according to any one of claims 1 to 4 An adjustment unit, the brake input device is used for receiving a driver's braking command and transmitting the braking command to the pedal feeling simulation device through the master cylinder, and the pedal feeling simulation device is used for sending the brake command to the pedal feeling simulation device. The driver feeds back pedal feeling information, and the hydraulic adjustment unit provides braking force for the first group of wheel cylinders and the second group of wheel cylinders by adjusting the brake fluid in the first hydraulic line and the second hydraulic line.
The brake-by-wire system according to claim 5, wherein the brake-by-wire system further comprises a controller for calculating a target braking force according to a braking command received by the braking input device, and The hydraulic adjustment unit is controlled to adjust the brake fluid in the first hydraulic line and the second hydraulic line according to the target braking force.
A control method for a brake-by-wire system, wherein the brake-by-wire system comprises:

A first hydraulic adjustment device comprising a first hydraulic cylinder, a first piston, a second piston, a first spring and a second spring, the first piston, the second piston and the first A cylinder wall of a hydraulic cylinder forms a first cavity, the second piston and the cylinder wall of the first hydraulic cylinder form a second cavity, the first spring connects the first piston and the second piston, so The second spring is connected to the second piston and the cylinder wall of the first hydraulic cylinder, the first cavity is connected to the first hydraulic pipeline, the second cavity is connected to the second hydraulic pipeline, and the first cavity is connected to the second hydraulic pipeline. A hydraulic pipeline is used to provide braking force to the first group of wheel cylinders, and the second hydraulic pipeline is used to provide braking force to the second group of wheel cylinders;

A second hydraulic adjustment device, the second hydraulic adjustment device includes a second hydraulic cylinder, a third piston and a third spring, the third piston and the cylinder wall of the third hydraulic cylinder form a third cavity, the first Three springs connect the third piston and the cylinder wall of the third hydraulic cylinder, the third cavity is connected to the first hydraulic pipeline through a first solenoid valve, and the third cavity is connected to the first hydraulic pipeline through a second solenoid valve The second hydraulic line is connected,

The control method includes:

The first hydraulic adjustment device and/or the second hydraulic adjustment device receive a control command sent by a controller;

The first hydraulic adjustment device and/or the second hydraulic adjustment device provides braking force to the first group of wheel cylinders and the second group of wheel cylinders according to the control command.
The method according to claim 7, wherein the first hydraulic adjustment device further comprises a first motor and a first push rod, the first push rod is connected to the first motor and the first piston, The second hydraulic adjustment device further includes a second motor and a second push rod, and the second push rod is connected to the second motor and the third piston.
The method according to claim 8, characterized in that the first hydraulic adjustment device and/or the second hydraulic adjustment device are the first set of wheel cylinders and the second set of wheel cylinders according to the control command Cylinders provide braking power, including:

The first motor pushes the first piston through the first push rod to compress the first cavity to adjust the brake fluid in the first hydraulic pipeline, so as to provide braking force for the first group of wheel cylinders;

The first piston pushes the second piston through the first spring to compress the second chamber to adjust the brake fluid in the second hydraulic pipeline, so as to provide braking force for the second group of wheel cylinders.
The method according to claim 8 or 9, wherein the first hydraulic adjustment device and/or the second hydraulic adjustment device are the first group of wheel cylinders and the second hydraulic adjustment device according to the control command The wheel cylinders provide braking power and include:

The first solenoid valve is opened, and the second motor pushes the third piston through the second push rod to compress the third cavity to adjust the brake fluid in the first hydraulic pipeline, so as to provide the first hydraulic pressure. A set of wheel cylinders provide braking force;

The second solenoid valve is opened, and the second motor pushes the third piston through the second push rod to compress the third cavity to adjust the brake fluid in the second hydraulic pipeline, so that the Two sets of wheel cylinders provide braking power.