CN114523945A - Braking system, braking method, readable storage medium and vehicle - Google Patents

Abstract

The invention discloses a braking system, a braking method, a readable storage medium and a vehicle, wherein the braking system comprises a plurality of hydraulic braking devices, a first pumping device, a second pumping device, a main cylinder, a mechanical braking device and a controller, the hydraulic braking devices comprise wheel brakes, wheel cylinder pressure increasing valves and wheel cylinder pressure reducing valves, and one ends of the wheel cylinder pressure increasing valves and one ends of the wheel cylinder pressure reducing valves are connected with the wheel brakes; the first pumping device is connected with the other ends of the wheel cylinder pressure increasing valves; the second pumping device is connected with the other ends of the wheel cylinder pressure increasing valves; the master cylinder is connected with the other ends of the wheel cylinder pressure relief valves, the first pumping device and the second pumping device; the controller is connected with the first pumping device, the second pumping device, the hydraulic braking device and the mechanical braking device. According to the brake system of the vehicle, the brake system is simple in structure, and the brake safety and stability can be improved.

Description

Braking system, braking method, readable storage medium and vehicle

Technical Field

The invention relates to the technical field of transportation, in particular to a vehicle braking system, a vehicle braking method suitable for the vehicle braking system, a computer readable storage medium for realizing the braking method and a vehicle for realizing the braking method.

Background

With the development of electronic technology, the EPB of the electronic parking system has almost become a standard product of a passenger car, and the ibooster of the electronic vacuum booster is more and more popular. Other electrical equipment such as EPB, ibooster, esp CAN carry out communication and diagnosis functions through the entire vehicle CAN network.

In the process of realizing the use, the passenger vehicle is required to be equipped with emergency braking to ensure the braking function when the service braking system fails.

Disclosure of Invention

A first aspect of the present invention is to provide a brake system for a vehicle, which is simple in structure and can improve braking safety and stability.

A second aspect of the invention is directed to a braking method of a vehicle.

A third aspect of the invention is directed to a computer-readable storage medium.

A fourth aspect of the invention is directed to a vehicle.

According to a first aspect of the present invention, a brake system for a vehicle includes a plurality of hydraulic brake devices, a first pumping device, a second pumping device, a master cylinder, a mechanical brake device, and a controller, wherein the hydraulic brake devices include a wheel brake, a wheel cylinder pressure increasing valve, and a wheel cylinder pressure reducing valve, and one end of the wheel cylinder pressure increasing valve and one end of the wheel cylinder pressure reducing valve are connected to the wheel brake; the first pumping device is connected with the other ends of the wheel cylinder pressure increase valves; the second pumping device is connected with the other ends of the wheel cylinder pressure increasing valves; the master cylinder is connected with the other ends of the wheel cylinder pressure relief valves, the first pumping device and the second pumping device; the controller is connected with the first pumping device, the second pumping device, the hydraulic braking device and the mechanical braking device, and is used for determining a braking mode of the braking system according to braking requirements and fault states of the first pumping device and the second pumping device.

According to the brake system of the vehicle, the brake system is simple in structure, and the brake safety and stability can be improved.

In addition, the braking system of the vehicle according to the above embodiment of the present invention may further have the following additional technical features:

optionally, each of the first pumping device and the second pumping device comprises a piston pump assembly, a motor and a control valve, the piston pump assembly has an oil inlet and an oil outlet, and the oil inlet of the piston pump assembly is connected with the master cylinder; the motor is connected with the piston pump assembly; the control valve is respectively connected with an oil outlet of the piston pump assembly and the wheel cylinder pressure increasing valves.

Optionally, the control valve comprises a first switch valve and a second switch valve, one end of the first switch valve is connected with the oil inlet of the piston pump assembly, and the other end of the first switch valve is connected with a part of the wheel cylinder pressure increase valves; one end of the second switch valve is connected with an oil inlet of the piston pump assembly, and the other end of the second switch valve is connected with the other part of the wheel cylinder pressure increasing valves.

Optionally, the first pumping device and the second pumping device further comprise a first sensor and a second sensor, and the first sensor is connected with the motor; the second sensor is connected with an oil outlet of the piston pump assembly, and the first sensor and the second sensor are in signal transmission with the controller.

According to a second aspect of the present invention, a braking method of a vehicle including the aforementioned braking system of the vehicle, the braking method includes: judging whether a braking demand exists; if the braking requirement exists, judging whether the first pumping device has a fault, and if the first pumping device has no fault, operating a normal braking mode; if the first pumping device has a fault, judging whether the second pumping device has a fault, and if the second pumping device has no fault, operating a standby braking mode; operating a mechanical braking mode if said second pumping means is faulty.

Optionally, the determining whether there is a braking demand includes: collecting a brake depth signal; and judging whether a braking demand exists according to the braking depth signal.

Optionally, the normal braking mode comprises: and judging whether the vehicle is unstable or not, if not, entering a normal four-wheel braking mode, and if so, entering a normal single-wheel braking mode.

Optionally, the normal four-wheel braking mode comprises: determining a target braking force according to the braking demand; controlling the first pumping device to be opened, the wheel cylinder pressure increase valves to be opened and the wheel cylinder pressure relief valves to be closed; acquiring actual braking force of a first pumping device, and determining a target position of the first pumping device according to the actual braking force and the target braking force; controlling the first pumping device to operate; stopping the first pumping device if the first pumping device reaches the target position.

Optionally, the normal single wheel braking mode comprises: determining an out-of-control wheel and a braking state of the out-of-control wheel according to the instability condition of the vehicle body; if the out-of-control wheel is in a pressurization state, controlling the first pumping device to be opened, the wheel cylinder pressurization valve corresponding to the out-of-control wheel to be opened, the wheel cylinder pressurization valve corresponding to the wheel which is not out-of-control to be closed, and the plurality of wheel cylinder pressure relief valves to be closed; if the out-of-control wheel is in a pressure relief state, controlling the first pumping device to be opened, the wheel cylinder pressure increase valves to be closed, the wheel cylinder pressure relief valves corresponding to the out-of-control wheel to be opened, and the wheel cylinder pressure relief valves corresponding to the wheels which are not out-of-control to be closed; and if the out-of-control wheel is in a pressure maintaining state, controlling the first pumping device to be opened, the wheel cylinder pressure increase valves to be closed and the wheel cylinder pressure relief valves to be closed.

Optionally, the backup braking mode comprises: and judging whether the vehicle is unstable or not, if not, entering a standby four-wheel braking mode, and if so, entering a standby single-wheel braking mode.

Optionally, the backup four-wheel braking mode comprises: determining a target braking force according to the braking demand; controlling the second pumping device to be opened, the wheel cylinder pressure increase valves to be opened and the wheel cylinder pressure relief valves to be closed; acquiring actual braking force of a second pumping device, and determining a target position of the second pumping device according to the actual braking force and the target braking force; controlling the second pumping device to operate; stopping the second pumping device if the second pumping device reaches the target position.

Optionally, the backup single wheel braking mode comprises: determining an out-of-control wheel and a braking state of the out-of-control wheel according to the instability condition of the vehicle body; if the out-of-control wheel is in a pressure-increasing state, controlling the second pumping device to be opened, the wheel cylinder pressure-increasing valve corresponding to the out-of-control wheel to be opened, the wheel cylinder pressure-increasing valve corresponding to the wheel which is not out-of-control to be closed, and the plurality of wheel cylinder pressure-reducing valves to be closed; if the out-of-control wheel is in a pressure relief state, controlling the second pumping device to be opened, the wheel cylinder pressure increase valves to be closed, the wheel cylinder pressure relief valves corresponding to the out-of-control wheel to be opened, and the wheel cylinder pressure relief valves corresponding to the wheels which are not out-of-control to be closed; and if the out-of-control wheel is in a pressure maintaining state, the second pumping device is controlled to be opened, the wheel cylinder pressure increasing valves are controlled to be closed, and the wheel cylinder pressure reducing valves are controlled to be closed.

According to a third aspect of the present invention, a computer readable storage medium has stored thereon a braking program which, when processed and executed, implements a braking method of a vehicle as previously described.

According to a fourth aspect of the invention, the vehicle comprises a memory, a processor and a braking program stored on the memory and executable on the processor, the processor implementing a braking method of the vehicle as described above when executing the braking program.

Drawings

FIG. 1 is a schematic diagram of a braking system of a vehicle according to one embodiment of the present invention.

FIG. 2 is a schematic diagram of a braking system of a vehicle according to one embodiment of the present invention.

FIG. 3 is a schematic diagram of a braking system of a vehicle according to one embodiment of the present invention.

Fig. 4 is a flow chart illustrating a braking method of a vehicle according to an embodiment of the present invention.

Fig. 5 is a flowchart illustrating a process of determining whether there is a braking demand in a braking method of a vehicle according to an embodiment of the present invention.

Fig. 6 is a flowchart illustrating a normal braking mode in a braking method of a vehicle according to an embodiment of the present invention.

Fig. 7 is a schematic flowchart of normal four-wheel braking in the normal braking mode in the braking method of the vehicle according to one embodiment of the present invention.

Fig. 8 is a flowchart illustrating a normal four-wheel brake in a normal braking mode in a braking method of a vehicle according to an embodiment of the present invention.

Fig. 9 is a schematic flowchart of normal one-wheel braking in the normal braking mode in the braking method of the vehicle according to one embodiment of the present invention.

Fig. 10 is a schematic flowchart of normal one-wheel braking in a normal braking mode in a braking method of a vehicle according to an embodiment of the present invention.

Fig. 11 is a flowchart illustrating a backup braking mode in a braking method of a vehicle according to an embodiment of the present invention.

Fig. 12 is a schematic flow diagram of a backup four-wheel brake in a backup braking mode in a braking method of a vehicle according to an embodiment of the present invention.

Fig. 13 is a schematic flow chart of a backup four-wheel brake in a backup braking mode in a braking method of a vehicle according to an embodiment of the present invention.

Fig. 14 is a schematic flow chart of a backup single wheel brake in a backup braking mode in a braking method of a vehicle according to an embodiment of the present invention.

Fig. 15 is a schematic flow chart of a backup single wheel brake in a backup braking mode in a braking method of a vehicle according to an embodiment of the present invention.

Fig. 16 is a comparison diagram of braking demand/braking depth (%) and braking force in a vehicle according to an embodiment of the present invention.

Reference numerals:

the brake system 100, the plurality of hydraulic brake devices 10, the wheel brakes 11, the wheel cylinder pressure increase valves 12, the wheel cylinder pressure release valves 13, the first pumping device 20, the second pumping device 30, the piston pump assembly 101, the motor 102, the first switch valve 103, the second switch valve 104, the first sensor 105, the second sensor 106, the master cylinder 40, the controller 50, and the mechanical brake device 60.

Detailed Description

The brake system, one of the most important systems in the vehicle running process, provides a guarantee for the safety and stability of the vehicle form, and various brake systems are provided in the related art, including:

1. the braking system is composed of two sets of hydraulic assembly structures: ibooster assembly + ESP assembly. Wherein the Iboost assembly comprises a brushless motor, a planetary gear, a ball screw, a piston pump and an Iboost controller. The ESP assembly consists of a brush motor, a plunger pump, an electromagnetic valve and an ESP controller; the working principle of the system is that an Iboost controller acquires the braking demand of a braking device, if the Iboost is not in fault, the Iboost applies braking, and if the Iboost fails, an ESP intervenes; in addition, if the whole vehicle is unstable, the ESP is involved under the condition that single-wheel braking is needed; supporting L3 intelligent driving;

2. the braking system is composed of two sets of hydraulic assembly structures: IPB assembly + ESP assembly. Wherein the IPB assembly comprises a brushless motor, a planetary gear, a ball screw, a piston pump, 14 solenoid valves and an IPB controller. The RC assembly consists of a brushless motor, a planetary gear, a ball screw, a piston pump, 2 electromagnetic valves and an RC controller; the working principle of the brake system is that an IPB controller acquires the braking requirement of a braking device, if the IPB is not in fault, four-wheel or single-wheel braking is completely applied by the IPB, and if the IPB is in failure, RC can only perform four-wheel braking; support unmanned above L3;

3. the braking system consists of two sets of same hydraulic assembly structures: ECB Assembly + ECB Assembly. The ECB assembly consists of a brush motor, an energy accumulator, a plunger pump, 14 electromagnetic valves and an ECB controller. The working principle of the system is that a main brake controller is arranged outside, the main brake controller collects IPB (internet protocol bus) to collect braking requirements of a braking device, the braking requirements are evenly distributed under the condition that two sets of assemblies are normal, and if one ECB fails, the braking requirements are completely distributed to the other set of assemblies. Support unmanned above L3.

Wherein Iboost refers to an electromechanical servo power-assisted system, ESP refers to an electronic vehicle body stabilizing system, IPB refers to an intelligent integrated brake system, and ECB refers to an electronic brake system

The brake systems all belong to a wire control decoupling brake system, support unmanned driving in a level of L3-L5, and meet an ASILD level. But the two sets of assemblies form, so that the occupied space is large, the cost is high, and the matching difficulty is high.

In order to solve some problems in the related art, the present invention provides a brake system for a vehicle, which is applicable not only to a fuel vehicle, a hybrid vehicle, and a pure electric vehicle, but also to an unmanned vehicle. The system is highly integrated, small in installation space, safe and capable of meeting ASID requirements and L4-L5-level intelligent driving.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

Referring to fig. 1 and 2, a brake system 100 of a vehicle according to a first aspect of the present invention includes a hydraulic brake device for braking a wheel, a first pumping device 20, a second pumping device 30, a master cylinder 40, and a controller 50, wherein the first pumping device 20 and the second pumping device 30 are pumping devices arranged in parallel and respectively used for supplying hydraulic oil to the hydraulic brake device, the first pumping device 20 and the second pumping device 30 can be operated independently, and the brake system 100 can further include more pumping devices. The master cylinder 40 is used to store and supply oil, and the controller 50 is used to control the operation of the entire brake system 100.

Specifically, the hydraulic brake device comprises a wheel brake 11, a wheel cylinder pressure increasing valve 12 and a wheel cylinder pressure reducing valve 13, wherein one end of the wheel cylinder pressure increasing valve 12 and one end of the wheel cylinder pressure reducing valve 13 are connected with the wheel brake 11, the wheel cylinder pressure increasing valve 12 and the wheel cylinder pressure reducing valve 13 are combined to form a structure for braking one wheel, the hydraulic brake device comprises a plurality of hydraulic brake devices 10, and the hydraulic brake devices 10 respectively brake a plurality of wheels. The first pumping means 20 is connected to the other ends of the plurality of wheel cylinder pressure increase valves 12, and the second pumping means 30 is connected to the other ends of the plurality of wheel cylinder pressure increase valves 12, and each of the first pumping means 20 and the second pumping means 30 may independently supply hydraulic pressure to the wheel brakes 11. The master cylinder 40 is connected to the other ends of the plurality of wheel cylinder pressure relief valves 13, the first pumping device 20, and the second pumping device 30. In use, the first and second pumping devices 20 and 30 may pump the oil of the master cylinder 40 to the hydraulic brake device, in which the first and second pumping devices 20 and 30 may pump the oil to the wheel brakes 11 if the wheel cylinder pressure increase valve 12 is opened, and the oil pressure of the wheel brakes 11 may be returned to the main pump if the wheel cylinder pressure release valve 13 is opened.

A controller 50 is connected to the first pumping means 20, the second pumping means 30 and the hydraulic braking means, the controller 50 being arranged to determine a braking mode of the braking system 100 based on the braking demand and the fault status of the first pumping means 20 and the second pumping means 30. For example, during vehicle operation, controller 50 obtains the status of first pumping device 20, and may pump oil using first pumping device 20 if first pumping device 20 is not malfunctioning, and may pump oil using second pumping device 30 if first pumping device 20 is malfunctioning and second pumping device 30 is not malfunctioning.

According to the brake system 100 of the vehicle of the embodiment of the present invention, by providing the first pumping device 20 and the second pumping device 30, when one of the first pumping device 20 and the second pumping device 30 fails, oil can be pumped by the other of the first pumping device 20 and the second pumping device 30, thereby achieving stable braking of the wheel. In addition, the first pumping device 20 and the second pumping device 30 share the same controller 50, so that the structure of the brake system 100 is simplified, the integration level of the brake system 100 is improved, the space occupied by the brake system 100 is reduced, and the space utilization rate of the brake system 100 is improved.

In addition, the braking system 100 of the present invention may further include a mechanical braking device 60, and the mechanical braking device 60 may be connected to the controller 50, and if both the first pumping device 20 and the second pumping device 30 fail, braking may be provided by using the mechanical braking device 60, thereby further improving the stability and safety of the braking system 100. Thereby further improving the stability and safety of the braking system 100.

Alternatively, as shown in fig. 1, each of the first pumping device 20 and the second pumping device 30 includes a piston pump assembly 101, a motor 102 and a control valve, the piston pump assembly 101 has an oil inlet and an oil outlet, and the oil inlet of the piston pump assembly 101 is connected to the master cylinder 40; the motor 102 is connected with the piston pump assembly 101; the control valves are respectively connected with an oil outlet of the piston pump assembly 101 and the plurality of wheel cylinder pressure-increasing valves 12. Wherein, the motor 102 can provide power for the piston pump assembly 101 to drive the piston pump assembly 101 to operate. The control valve can connect and disconnect the first pumping device 20 to and from the hydraulic brake device, and when the control valve is opened, the piston pump assembly 101 can drive oil to the hydraulic brake device through the control valve. By configuring the first and second pumping devices 20 and 30 to be substantially identical, control logic for the first and second pumping devices 20 and 30 may be effectively simplified, and it may be achieved that the first and second pumping devices 20 and 30 pump oil to the hydraulic brake device in substantially identical patterns, and a stable brake oil pressure may be provided to the hydraulic brake device regardless of whether the first pumping device 20 or the second pumping device 30 is operated.

In addition, the control valves provided in the first pumping device 20 and the second pumping device 30 can improve the operation stability of the pumping devices, and can provide quick maintenance and avoid fault increase when the first pumping device 20 and/or the second pumping device 30 fails.

It should be noted that, in the present invention, the term "first pumping device 20 is opened" means that the control valve of the first pumping device 20 is opened; likewise, the second pumping device 30 being open means that the control valve of the second pumping device 30 is open. In addition, the first pumping device 20 and the second pumping device 30 in the present invention may be opened in other situations, for example, in the embodiment without a control valve, the first pumping device 20 in the present invention may be opened, which means that the piston pump assembly 101 of the first pumping device 20 is opened; likewise, the second pumping device 30 being open may also mean that the piston pump assembly 101 of the second pumping device 30 is open.

It should be noted that first pumping device 20 and second pumping device 30 of the present invention may not include control valves. The present invention is mainly illustrated by the first pumping device 20 and the second pumping device 30 both including control valves, and is not intended to limit the scope of the present invention.

The control valve in the present invention may be a valve structure suitable for switching on and off the piston pump assembly 101 and the plurality of hydraulic brakes 10, and the present invention is mainly described by taking the example that the control valve includes the first switch valve 103 and the second switch valve 104, which should not be construed as limiting the scope of the present invention.

As shown in fig. 1, in some embodiments of the present invention, the control valve includes a first switching valve 103 and a second switching valve 104, one end of the first switching valve 103 is connected to an oil inlet of the piston pump assembly 101, and the other end of the first switching valve 103 is connected to a portion of the plurality of wheel cylinder pressure increase valves 12; one end of the second on-off valve 104 is connected to an oil inlet of the piston pump assembly 101, and the other end of the second on-off valve 104 is connected to another portion of the plurality of wheel cylinder pressure increase valves 12. By opening and closing the first switching valve 103 and the second switching valve 104, the piston pump assembly 101 can be connected to and disconnected from the plurality of hydraulic brake devices 10, and stable control of the first pumping device 20 and the second pumping device 30 can be achieved. By arranging the first switching valve 103 and the second switching valve 104, the stability and the safety of the first pumping device 20 and the second pumping device 30 can be improved, the control difficulty of the first pumping device 20 and the second pumping device 30 can be reduced, and the stability and the safety of the brake system 100 can be improved.

In order to know the operation conditions of the first pumping device 20 and the second pumping device 30 in real time, various sensors may be disposed on the first pumping device 20 and the second pumping device 30 in the present invention, so as to facilitate the control of the first pumping device 20 and the second pumping device 30, simplify the control logic, and improve the stability and safety of the brake system 100.

Referring to fig. 1, in some embodiments of the present invention, the first pumping device 20 and the second pumping device 30 may further include a first sensor 105, the first sensor 105 is connected to the motor 102, and the first sensor 105 may be used to obtain a position of the motor 102, so as to provide stable oil and hydraulic pressure to the hydraulic brake device, thereby improving stability of the brake system 100, wherein the first sensor 105 is in signal communication with the controller 50.

In addition, the first pumping device 20 and the second pumping device 30 of the present invention may further include a second sensor 106, the second sensor 106 is connected to the oil outlet of the piston pump assembly 101, the second sensor 106 may be a pressure sensor, and may acquire an operation condition of the piston pump assembly 101, so as to further stably provide stable oil and hydraulic pressure to the hydraulic brake device, and improve stability of the brake system 100, where the second sensor 106 is in signal transmission with the controller 50.

In the brake system 100 according to an embodiment of the present invention, the controller 50, the mechanical brake device 60, the hydraulic brake device, the first pumping device 20, and the second pumping device 30 are mainly included. The first pumping device 20 mainly includes a motor 102 (which may be a brushless motor), a first sensor 105 (a motor position/angle sensor), a second sensor 106 (a pressure sensor), a piston pump assembly 101 (which mainly includes a planetary gear, a ball screw, and a piston pump), and control valves (a first switch valve 103 and a second switch valve 104). The second pumping device 30 mainly includes a motor 102 (which may be a brushless motor), a first sensor 105 (a motor position/angle sensor), a second sensor 106 (a pressure sensor), a piston pump assembly 101 (mainly composed of a planetary gear, a ball screw, and a piston pump), and spare control valves (a first switching valve 103 and a second switching valve 104). The hydraulic brake device includes a plurality of devices, and mainly includes a wheel cylinder pressure increase valve 12 and a wheel cylinder pressure decrease valve 13. Wherein each of the first pumping device 20 and the second pumping device 30 is line-connected to the wheel cylinder pressure-increasing valve 12 through the first opening/closing valve 103 and the second opening/closing valve 104.

For example, the vehicle of the present invention may include four hydraulic braking devices, and the four hydraulic braking devices are respectively used for braking the left front wheel, the right rear wheel, the left rear wheel and the right front wheel, wherein the first switch valve 103 is connected to the wheel cylinder pressure increasing valve 12 corresponding to the left rear wheel and the wheel cylinder pressure increasing valve 12 corresponding to the right front wheel, and the second switch valve 104 is connected to the wheel cylinder pressure increasing valve 12 corresponding to the left front wheel and the wheel cylinder pressure increasing valve 12 corresponding to the right rear wheel.

As shown in fig. 3, in the present invention, the controller 50 and the mechanical control device are combined to form a device I; the first pumping device 20 in the present invention is combined with a plurality of hydraulic braking devices 10 to construct a device II to achieve normal braking; and the second pumping device 30 acts as device III to achieve back-up braking. The second pumping device 30 is connected to a plurality of hydraulic brake devices 10. The vehicle of the present invention further includes a power supply device for supplying electric power to the braking system 100, and a braking device, which may be a pedal, for generating a signal indicating whether braking is required. As shown in fig. 1, the plurality of hydraulic brake devices are generally designated by the reference numeral 10.

Compared with the prior art, the invention has obvious difference in structure, and in order to meet the requirement of the unmanned vehicle on the level of L3 or the ASILD level, the brake system in the prior art is realized by combining two sets of hydraulic assemblies. The advantage is under the same circumstances that satisfies the security and support unmanned more than the grade of L3, and whole car arranges that the space is little, and the whole cost is low, simultaneously because two sets of hydraulic pressure pipelines of a controller control, the matching degree of difficulty can reduce, and the braking links up can be more excellent, and whole car braking ride comfort can be stronger.

In addition, the master cylinder of the present invention may be shared with other hydraulic systems in the vehicle.

According to a second aspect of the present invention, a braking method for a vehicle including the aforementioned braking system for a vehicle, the braking method includes:

whether a braking requirement exists is judged, namely whether braking is needed in the running process of the vehicle, for example, a brake pedal reaches a preset braking depth, or the intelligent control system determines whether braking is needed, for example, the intelligent control system determines whether braking is needed according to whether the vehicle is about to reach a destination, whether the distance between the vehicle and a front vehicle is too small, whether a safety indicator light signal exists, and the like.

If there is a braking demand, it is determined whether the first pumping means has a failure. Whether the first pumping device has a fault or not can be judged according to whether the first pumping device is abnormal or not, for example, whether the first pumping device feeds back a signal or whether the feedback signal of the first pumping device is abnormal or not can be judged.

If the first pumping device is not in fault, operating a normal braking mode, and braking the vehicle by the braking system by adopting the first pumping device; if the first pumping means is malfunctioning, the normal braking mode is not used, but it is determined whether the second pumping means is malfunctioning. If the second pumping device is not in fault, the backup braking mode is operated, and the braking system brakes the vehicle by adopting the second pumping device.

If the second pumping device has a fault, the first pumping device and the second pumping device are not used for braking at the moment, and the braking system adopts a mechanical braking device for braking by utilizing a mechanical braking mode.

With reference to fig. 1 to 4, according to the braking method provided by the embodiment of the invention, the effective braking of the vehicle is realized by judging the fault conditions of the first pumping device and the second pumping device, and the stability and the safety of the vehicle operation are improved.

In addition, the braking method applies the braking system, and by arranging the first pumping device and the second pumping device, when one of the first pumping device and the second pumping device fails, the other one of the first pumping device and the second pumping device can still be used for pumping oil, so that stable braking on the wheels is realized. In addition, the first pumping device and the second pumping device share the same controller, so that the structure of the brake system is simplified, the integration level of the brake system is improved, the space occupied by the brake system is reduced, and the space utilization rate of the brake system is improved.

It should be noted that the foregoing judgment on the braking requirement, the judgment on whether the first pumping device has a fault, the judgment on whether the second pumping device has a fault, and the like are all specific embodiments of the present invention, which are intended to facilitate the understanding of the technical solutions of the present application by those skilled in the art, and are not intended to limit the scope of the present invention, and the following detailed description will be made on each of the foregoing control steps.

As shown in FIG. 5, in some embodiments of the present invention, the determining whether there is a braking demand comprises: and (4) collecting a braking depth signal, and judging whether a braking demand exists according to the braking depth signal. The braking depth signal is utilized to judge the braking requirement, and the safety and the stability of the vehicle braking system can be improved.

Specifically, in the present invention, it may be configured to determine that a braking demand exists when the braking depth signal is greater than 0.

As shown in fig. 6, in some embodiments of the invention, the normal braking mode includes: and judging whether the vehicle is unstable or not, if not, entering a normal four-wheel braking mode, and if so, entering a normal single-wheel braking mode. Whether the vehicle is unstable or not can be judged according to the instability condition of the vehicle body, for example, whether the vehicle is unstable or not can be judged by arranging an angular speed sensor on the vehicle body and the like. Through the respective control of vehicle instability and vehicle instability, the safety and stability of the vehicle in the braking process can be realized, the stable braking of the vehicle can be ensured in the instability and instability-free state, and the stability and the safety of the vehicle in the form process are improved.

As shown in FIG. 7, in some embodiments of the present invention, the normal four-wheel braking mode includes: determining a target braking force according to the braking demand; controlling the first pumping device to be opened, the plurality of wheel cylinder pressure increase valves to be opened and the plurality of wheel cylinder pressure relief valves to be closed; acquiring the actual braking force of the first pumping device, and determining the target position of the first pumping device according to the actual braking force and the target braking force; controlling the first pumping device to operate; the first pumping means is stopped if it reaches the target position. At this time, the first pumping device provides reasonable braking hydraulic pressure to the plurality of wheel brakes, and stable braking of each wheel is guaranteed. According to the comparison between the target braking force and the actual braking force, a reasonable braking mode can be obtained, so that the stable braking of the wheels is realized, and the stability and the safety of the vehicle are improved.

Specifically, in combination with the foregoing embodiment, the hydraulic brake device may include four, the four hydraulic brake devices include four wheel cylinder pressure-increasing valves and four wheel cylinder pressure-reducing valves in total, the first pumping device and the second pumping device each include a piston pump assembly, a motor, a first switching valve, a second switching valve, a first sensor and a second sensor,

as shown in fig. 8, the normal four-wheel braking mode of the present invention includes:

determining a target braking force according to the braking demand;

the first on-off valve and the second on-off valve of the first pumping device are opened, the first on-off valve and the second on-off valve of the second pumping device are closed, the four wheel cylinder pressure increasing valves are opened, and the four wheel cylinder pressure reducing valves are closed;

and judging the magnitude relation between the target braking force of the current braking and the target braking force of the last braking, entering a normal pressure increasing mode if the target braking force of the current braking is greater than the target braking force of the last braking, entering a normal pressure maintaining mode if the target braking force of the current braking is equal to the target braking force of the last braking, and entering a normal pressure releasing mode if the target braking force of the current braking is less than the target braking force of the last braking.

Acquiring actual braking force through a second sensor of the first pumping device in a normal pressurization mode; calculating a target position of a motor of the first pumping device according to a difference value between the actual braking force and the target braking force; acquiring the actual position of the motor through a first sensor of the first pumping device; controlling a motor of the first pumping device to rotate positively; judging whether a motor of the first pumping device reaches a target position; if the motor of the first pumping device reaches the target position, the motor of the first pumping device is controlled to remain stationary.

Under a normal pressure relief mode, acquiring actual braking force through a second sensor of the first pumping device; calculating a target position of a motor of the first pumping device according to a difference value between the actual braking force and the target braking force; acquiring the actual position of the motor through a first sensor of the first pumping device; controlling a motor of the first pumping device to reversely rotate; judging whether a motor of the first pumping device reaches a target position or not; if the motor of the first pumping device reaches the target position, the motor of the first pumping device is controlled to remain stationary.

In the normal pressure maintaining mode, the motor of the first pumping device is controlled to be kept still.

As shown in FIG. 9, in some embodiments of the invention, the normal single wheel braking mode includes: determining an out-of-control wheel and a braking state of the out-of-control wheel according to the instability condition of the vehicle body; if the out-of-control wheel is in a pressure-increasing state, controlling the first pumping device to be opened, the wheel cylinder pressure-increasing valve corresponding to the out-of-control wheel to be opened, the wheel cylinder pressure-increasing valve corresponding to the wheel which is not out-of-control to be closed and the plurality of wheel cylinder pressure-reducing valves to be closed; if the out-of-control wheel is in a pressure relief state, controlling the first pumping device to be opened, the plurality of wheel cylinder pressure increase valves to be closed, the wheel cylinder pressure relief valves corresponding to the out-of-control wheel to be opened, and the wheel cylinder pressure relief valves corresponding to the wheels which are not out-of-control to be closed; and if the out-of-control wheel is in a pressure maintaining state, the first pumping device is controlled to be opened, the plurality of wheel cylinder pressure increasing valves are controlled to be closed, and the plurality of wheel cylinder pressure reducing valves are controlled to be closed.

When the out-of-control wheel is in a pressurization state, the first pumping device conveys oil to a wheel brake of the out-of-control wheel, so that the increase of the out-of-control vehicle is realized; when the out-of-control wheel is in a pressure relief state, the wheel cylinder pressure relief valve corresponding to the out-of-control wheel is opened, so that the pressure relief of the wheel brake corresponding to the out-of-control wheel is realized; when the out-of-control wheel is in the pressure maintaining state, the wheel cylinder pressure relief valve and the wheel cylinder pressure increasing valve corresponding to the out-of-control wheel are both closed, and the pressure maintaining of the wheel brake corresponding to the out-of-control wheel can be realized.

The pressure increasing, pressure releasing and pressure maintaining states of the out-of-control wheel all refer to wheel cylinder states of a wheel brake for braking the out-of-control wheel.

Specifically, in combination with the foregoing embodiment, the hydraulic brake device may include four, the four hydraulic brake devices include four wheel cylinder pressure-increasing valves and four wheel cylinder pressure-reducing valves in total, the first pumping device and the second pumping device each include a piston pump assembly, a motor, a first switching valve, a second switching valve, a first sensor and a second sensor,

as shown in fig. 10, the normal four-wheel braking mode of the present invention includes:

determining an out-of-control wheel and a braking state of the out-of-control wheel according to the instability condition of the vehicle body;

judging which state of pressurization, pressure relief and pressure maintaining is adopted for the unstable wheel;

if the out-of-control wheel is in a pressurization state, controlling a first switch valve and a second switch valve of a first pumping device to be opened, closing the first switch valve and the second switch valve of a second pumping device, opening a wheel cylinder pressurization valve corresponding to the out-of-control wheel, closing a wheel cylinder pressurization valve corresponding to the wheel which is not out-of-control, and closing four wheel cylinder pressure relief valves;

if the out-of-control wheel is in a pressure relief state, controlling a first switch valve and a second switch valve of the first pumping device to be opened, closing the first switch valve and the second switch valve of the second pumping device, closing the four wheel cylinder pressure increase valves, opening a wheel cylinder pressure release valve corresponding to the out-of-control wheel, and closing a wheel cylinder pressure release valve corresponding to the wheel which is not out-of-control;

and if the out-of-control wheel is in a pressure maintaining state, controlling the first switching valve and the second switching valve of the first pumping device to be opened, closing the first switching valve and the second switching valve of the second pumping device, closing the four wheel cylinder pressure increasing valves and closing the four wheel cylinder pressure reducing valves.

As shown in fig. 11, in some embodiments of the invention, the backup braking mode includes: and judging whether the vehicle is unstable or not, if not, entering a standby four-wheel braking mode, and if so, entering a standby single-wheel braking mode. Whether the vehicle is unstable or not can be judged according to the instability condition of the vehicle body, for example, whether the vehicle is unstable or not can be judged by arranging an angular speed sensor on the vehicle body and the like. Through the respective control of vehicle instability and vehicle instability, the safety and stability of the vehicle in the braking process can be realized, the stable braking of the vehicle can be ensured in the instability and instability-free state, and the stability and the safety of the vehicle in the form process are improved.

As shown in FIG. 12, in some embodiments of the invention, the standby four-wheel braking mode includes: determining a target braking force according to the braking demand; controlling the second pumping device to be opened, the plurality of wheel cylinder pressure-increasing valves to be opened and the plurality of wheel cylinder pressure-reducing valves to be closed; acquiring the actual braking force of the second pumping device, and determining the target position of the second pumping device according to the actual braking force and the target braking force; controlling the second pumping device to operate; the second pumping means is stopped if the second pumping means reaches the target position. At this time, the second pumping device provides reasonable brake hydraulic pressure to the plurality of wheel brakes, and stable braking of each wheel is guaranteed. According to the comparison between the target braking force and the actual braking force, a reasonable braking mode can be obtained, so that the stable braking of the wheels is realized, and the stability and the safety of the vehicle are improved.

Specifically, in combination with the foregoing embodiment, the hydraulic brake device may include four, the four hydraulic brake devices include four wheel cylinder pressure-increasing valves and four wheel cylinder pressure-reducing valves in total, the first pumping device and the second pumping device each include a piston pump assembly, a motor, a first switching valve, a second switching valve, a first sensor and a second sensor,

as shown in fig. 13, the standby four-wheel braking mode of the present invention includes:

determining a target braking force according to the braking demand;

the first on-off valve and the second on-off valve of the first pumping device are closed, the first on-off valve and the second on-off valve of the second pumping device are closed, the four wheel cylinder pressure increasing valves are opened, and the four wheel cylinder pressure reducing valves are closed;

judging the magnitude relation between the target braking force of the current braking and the target braking force of the last braking, if the target braking force of the current braking is larger than the target braking force of the last braking, entering a standby pressurization mode, if the target braking force of the current braking is equal to the target braking force of the last braking, entering a standby pressure maintaining mode, and if the target braking force of the current braking is smaller than the target braking force of the last braking, entering a standby pressure relief mode.

Acquiring actual braking force through a second sensor of a second pumping device in a standby pressurization mode; calculating a target position of a motor of the second pumping device according to the difference value between the actual braking force and the target braking force; acquiring the actual position of the motor through a first sensor of the second pumping device; controlling a motor of the second pumping device to rotate positively; judging whether a motor of the second pumping device reaches a target position; if the motor of the second pumping device reaches the target position, the motor of the second pumping device is controlled to remain stationary.

Acquiring actual braking force through a second sensor of a second pumping device in a standby pressure relief mode; calculating a target position of a motor of the second pumping device according to the difference value between the actual braking force and the target braking force; acquiring the actual position of the motor through a first sensor of the second pumping device; controlling the motor of the second pumping device to reversely rotate; judging whether a motor of the second pumping device reaches a target position; if the motor of the second pumping device reaches the target position, the motor of the second pumping device is controlled to remain stationary.

And in the standby pressure maintaining mode, controlling the motor of the second pumping device to keep still.

As shown in FIG. 14, in some embodiments of the invention, the backup single wheel braking mode includes: determining an out-of-control wheel and a braking state of the out-of-control wheel according to the instability condition of the vehicle body; if the out-of-control wheel is in a pressure-increasing state, the second pumping device is controlled to be opened, the wheel cylinder pressure-increasing valve corresponding to the out-of-control wheel is opened, the wheel cylinder pressure-increasing valve corresponding to the wheel which is not out-of-control is closed, and the plurality of wheel cylinder pressure-reducing valves are controlled to be closed; if the out-of-control wheel is in a pressure relief state, the second pumping device is controlled to be opened, the wheel cylinder pressure increase valves are controlled to be closed, the wheel cylinder pressure relief valves corresponding to the out-of-control wheel are controlled to be opened, and the wheel cylinder pressure relief valves corresponding to the wheels which are not out-of-control are controlled to be closed; and if the out-of-control wheel is in a pressure maintaining state, the second pumping device is controlled to be opened, the wheel cylinder pressure increasing valves are controlled to be closed, and the wheel cylinder pressure reducing valves are controlled to be closed.

When the out-of-control wheel is in a pressurization state, the first pumping device conveys oil to a wheel brake of the out-of-control wheel, so that the increase of the out-of-control vehicle is realized; when the out-of-control wheel is in a pressure relief state, the wheel cylinder pressure relief valve corresponding to the out-of-control wheel is opened, so that the pressure relief of the wheel brake corresponding to the out-of-control wheel is realized; when the out-of-control wheel is in the pressure maintaining state, the wheel cylinder pressure relief valve and the wheel cylinder pressure increasing valve corresponding to the out-of-control wheel are both closed, and the pressure maintaining of the wheel brake corresponding to the out-of-control wheel can be realized.

The pressure increasing, pressure releasing and pressure maintaining states of the out-of-control wheel all refer to wheel cylinder states of a wheel brake for braking the out-of-control wheel.

Specifically, in combination with the foregoing embodiment, the hydraulic braking device may include four hydraulic braking devices, the four hydraulic braking devices include four wheel cylinder pressure increasing valves and four wheel cylinder pressure reducing valves in total, the first pumping device and the second pumping device each include a piston pump assembly, a motor, a first switching valve, a second switching valve, a first sensor and a second sensor,

as shown in fig. 15, the standby four-wheel braking mode of the present invention includes:

determining an out-of-control wheel and a braking state of the out-of-control wheel according to the instability condition of the vehicle body;

judging the unstable wheel is in any state of pressurization, pressure relief and pressure maintaining;

if the out-of-control wheel is in a pressurization state, controlling a first switch valve and a second switch valve of a first pumping device to be closed, opening a first switch valve and a second switch valve of a second pumping device, opening a wheel cylinder pressurization valve corresponding to the out-of-control wheel, closing a wheel cylinder pressurization valve corresponding to the wheel which is not out-of-control, and closing four wheel cylinder pressure relief valves;

if the out-of-control wheel is in a pressure relief state, controlling a first switch valve and a second switch valve of a first pumping device to be closed, opening the first switch valve and the second switch valve of a second pumping device, closing four wheel cylinder pressure increase valves, opening a wheel cylinder pressure release valve corresponding to the out-of-control wheel, and closing a wheel cylinder pressure release valve corresponding to the wheel which is not out-of-control;

and if the out-of-control wheel is in a pressure maintaining state, the first switching valve and the second switching valve of the first pumping device are controlled to be closed, the first switching valve and the second switching valve of the second pumping device are opened, the four wheel cylinder pressure increasing valves are closed, and the four wheel cylinder pressure reducing valves are closed.

With reference to fig. 1 to 15, in the present invention, the controller 50 is combined with a mechanical control device to form a device I; the first pumping device 20 in the present invention is combined with a plurality of hydraulic braking devices 10 to construct a device II to achieve normal braking; and the second pumping device 30 acts as device III to achieve back-up braking. The second pumping device 30 is connected to a plurality of hydraulic brake devices 10. The braking system of the present invention is classified according to whether the devices II and III are malfunctioning: a normal service braking mode and a backup braking mode and a mechanical braking mode. The braking method of the invention comprises the following steps:

step 1, collecting a braking depth signal of a braking device to obtain a braking demand;

step 2, judging whether a driver has a braking demand at present, and if so, entering step 3;

step 3, judging whether the device II has faults or not, and if not, entering a step 4, namely a normal braking mode; if the fault exists, judging whether the device III has the fault, if the device III has the fault, entering a step 5-standby braking mode, and if the device III has the fault, entering a mechanical braking mode (generating braking force completely by stepping on the pedal)

Step 4, under the normal braking mode, if the vehicle is not unstable, entering a 6-normal four-wheel braking mode; if the vehicle is unstable, entering a 7-normal single-wheel braking mode;

step 5, under the standby braking mode, if the vehicle is not unstable, entering an 8-standby four-wheel braking mode; if the vehicle is unstable, entering a 9-standby single-wheel braking mode;

step 6, under the normal four-wheel braking mode, firstly calculating a target braking force according to a braking demand; the first switching valve and the second switching valve of the first pumping device are opened, the first switching valve and the second switching valve of the second pumping device are closed, the four wheel cylinder pressure-increasing valves are opened, and the four wheel cylinder pressure-reducing valves are closed; acquiring actual braking force through a second sensor of the first pumping device, calculating a target position of a motor of the first pumping device according to a difference value of the actual braking force and the target braking force, and acquiring the actual position of the motor through a first sensor of the first pumping device; controlling a motor of the first pumping device to rotate forwards until the motor of the first pumping device reaches a target position, and controlling the motor of the first pumping device to keep still;

step 7, under a normal single-wheel braking mode, calculating the braking state of the out-of-control wheel according to the instability condition of the vehicle body, and if the out-of-control wheel is in a pressurization state, controlling a first switch valve and a second switch valve of a first pumping device to be opened, closing the first switch valve and the second switch valve of a second pumping device, opening a wheel cylinder pressurization valve corresponding to the out-of-control wheel, closing a wheel cylinder pressurization valve corresponding to the wheel which is not out-of-control, and closing four wheel cylinder pressure relief valves; if the out-of-control wheel is in a pressure relief state, controlling a first switch valve and a second switch valve of the first pumping device to be opened, closing the first switch valve and the second switch valve of the second pumping device, closing the four wheel cylinder pressure increase valves, opening a wheel cylinder pressure release valve corresponding to the out-of-control wheel, and closing a wheel cylinder pressure release valve corresponding to the wheel which is not out-of-control; if the out-of-control wheel is in a pressure maintaining state, controlling a first switch valve and a second switch valve of the first pumping device to be opened, closing the first switch valve and the second switch valve of the second pumping device, closing four wheel cylinder pressure increasing valves and closing four wheel cylinder pressure reducing valves;

step 8, determining a target braking force according to a braking demand in a standby four-wheel braking mode; the first switching valve and the second switching valve of the first pumping device are closed, the first switching valve and the second switching valve of the second pumping device are closed, the four wheel cylinder pressure-increasing valves are opened, and the four wheel cylinder pressure-reducing valves are closed; (ii) a Acquiring actual braking force through a second sensor of a second pumping device; calculating a target position of a motor of the second pumping device according to the difference value between the actual braking force and the target braking force; acquiring the actual position of the motor through a first sensor of the second pumping device; controlling a motor of the second pumping device to rotate positively; controlling the motor of the second pumping device to keep still until the motor of the second pumping device reaches the target position;

step 9, under a standby single-wheel braking mode, determining the braking state of an out-of-control wheel according to the instability condition of a vehicle body, if the out-of-control wheel is in a pressurization state, controlling a first switch valve and a second switch valve of a first pumping device to be closed, controlling the first switch valve and the second switch valve of a second pumping device to be opened, opening a wheel cylinder pressurization valve corresponding to the out-of-control wheel, closing a wheel cylinder pressurization valve corresponding to a wheel which is not out-of-control, and closing four wheel cylinder pressure relief valves; if the out-of-control wheel is in a pressure relief state, controlling a first switch valve and a second switch valve of a first pumping device to be closed, opening the first switch valve and the second switch valve of a second pumping device, closing four wheel cylinder pressure increase valves, opening a wheel cylinder pressure release valve corresponding to the out-of-control wheel, and closing a wheel cylinder pressure release valve corresponding to the wheel which is not out-of-control; and if the out-of-control wheel is in a pressure maintaining state, the first switching valve and the second switching valve of the first pumping device are controlled to be closed, the first switching valve and the second switching valve of the second pumping device are opened, the four wheel cylinder pressure increasing valves are closed, and the four wheel cylinder pressure reducing valves are closed.

In addition, as shown in fig. 16, a comparison diagram of the braking demand/braking depth (%) with the braking force is shown.

In conjunction with fig. 1 to 3, the vehicle of the present invention may have four wheels, i.e., a front left wheel (FL), a rear right wheel (RR), a rear left wheel (RL), and a front right wheel (FR)

In addition, the mechanical brake device in the present invention may be connected to a plurality of hydraulic brake devices. Wherein, the mechanical braking device can include: the third pumping device is connected with the valve assembly, the valve assembly is connected with the wheel cylinder pressure increasing valves and comprises a first valve, the first valve can be arranged to be linked with a vehicle brake pedal, the state of the first valve is changed through the brake pedal, oil of the third pumping device is switched between a state of pumping the oil to the hydraulic braking devices and a state of not pumping the oil to the hydraulic braking devices, and therefore the purpose of mechanical braking through the brake pedal is achieved.

In addition, the valve assembly may further include a second valve connected to one of the plurality of hydraulic brake devices, and a third valve connected to another of the plurality of hydraulic brake devices. The valve assembly of the present invention.

According to a third aspect of the present invention, a computer readable storage medium has stored thereon a braking program which, when processed and executed, implements a braking method of a vehicle as previously described.

According to the computer-readable storage medium provided by the embodiment of the invention, the control of the first pumping device and the second pumping device can be realized, and the stability and the safety of a vehicle brake system are improved.

Compared with the prior art, the invention has obvious difference in structure, and in order to meet the requirement of the unmanned vehicle on the level of L3 or the ASILD level, the brake system in the prior art is realized by combining two sets of hydraulic assemblies. The advantage is under the same circumstances that satisfies the security and support unmanned more than the grade of L3, and whole car arranges that the space is little, and the whole cost is low, simultaneously because two sets of hydraulic pressure pipelines of a controller control, the matching degree of difficulty can reduce, and the braking links up can be more excellent, and whole car braking ride comfort can be stronger.

According to a fourth aspect of the invention, a vehicle comprises a memory, a processor and a braking program stored on the memory and executable on the processor, the processor implementing a braking method of the vehicle as described above when executing the braking program.

According to the vehicle provided by the embodiment of the invention, the fault conditions of the first pumping device and the second pumping device are judged, so that the vehicle is effectively braked, and the stability and the safety of the vehicle operation are improved.

In addition, the braking method applies the braking system, and by arranging the first pumping device and the second pumping device, when one of the first pumping device and the second pumping device fails, the other one of the first pumping device and the second pumping device can still be used for pumping oil, so that stable braking on the wheels is realized. In addition, the first pumping device and the second pumping device share the same controller, so that the structure of the brake system is simplified, the integration level of the brake system is improved, the space occupied by the brake system is reduced, and the space utilization rate of the brake system is improved.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims (14)

1. A braking system for a vehicle, characterized in that the braking system comprises:

the hydraulic braking devices comprise wheel brakes, wheel cylinder pressure increasing valves and wheel cylinder pressure reducing valves, and one ends of the wheel cylinder pressure increasing valves and one ends of the wheel cylinder pressure reducing valves are connected with the wheel brakes;

the first pumping device is connected with the other ends of the wheel cylinder pressure increase valves;

a second pumping device connected to the other ends of the wheel cylinder pressure increase valves;

the master cylinder is connected with the other ends of the wheel cylinder pressure relief valves, the first pumping device and the second pumping device;

a mechanical braking device;

a controller coupled to the first pumping arrangement, the second pumping arrangement, the plurality of hydraulic braking devices, and the mechanical braking device, the controller configured to determine a braking mode of the braking system based on a braking demand and a fault condition of the first pumping arrangement and the second pumping arrangement.

2. The braking system of a vehicle of claim 1, wherein the first pumping device and the second pumping device each comprise:

the piston pump assembly is provided with an oil inlet and an oil outlet, and the oil inlet of the piston pump assembly is connected with the main cylinder;

the motor is connected with the piston pump assembly;

and the control valves are respectively connected with the oil outlet of the piston pump assembly and the wheel cylinder pressure increasing valves.

3. The brake system of a vehicle according to claim 2, wherein the control valve includes:

one end of the first switch valve is connected with an oil inlet of the piston pump assembly, and the other end of the first switch valve is connected with one part of the wheel cylinder pressure increasing valves;

one end of the second switch valve is connected with an oil inlet of the piston pump assembly, and the other end of the second switch valve is connected with the other part of the wheel cylinder pressure increasing valves.

4. The braking system of a vehicle of claim 2, wherein the first and second pumping devices further comprise:

the first sensor is connected with the motor;

a second sensor connected to an oil outlet of the piston pump assembly,

wherein the first sensor and the second sensor are in signal transmission with the controller.

5. A braking method of a vehicle including a braking system of the vehicle according to any one of claims 1 to 4, characterized by comprising:

judging whether a braking demand exists;

if the braking requirement exists, judging whether the first pumping device has a fault, and if the first pumping device has no fault, operating a normal braking mode;

if the first pumping device has a fault, judging whether the second pumping device has a fault, and if the second pumping device has no fault, operating a standby braking mode;

operating a mechanical braking mode if said second pumping means is faulty.

6. The method of claim 5, wherein the determining whether there is a braking demand comprises:

collecting a brake depth signal;

and judging whether a braking demand exists according to the braking depth signal.

7. The braking method of a vehicle according to claim 5, characterized in that the normal braking mode includes:

it is determined whether the vehicle is unstable or not,

and if the vehicle is not unstable, entering a normal four-wheel braking mode, and if the vehicle is unstable, entering a normal single-wheel braking mode.

8. The braking method of a vehicle according to claim 7, wherein the normal four-wheel braking mode includes:

determining a target braking force according to the braking demand;

controlling the first pumping device to be opened, the wheel cylinder pressure increase valves to be opened and the wheel cylinder pressure relief valves to be closed;

acquiring actual braking force of a first pumping device, and determining a target position of the first pumping device according to the actual braking force and the target braking force;

controlling the first pumping device to operate;

stopping the first pumping device if the first pumping device reaches the target position.

9. The braking method of a vehicle according to claim 7, wherein the normal single-wheel braking mode includes:

determining an out-of-control wheel and a braking state of the out-of-control wheel according to the instability condition of the vehicle body;

if the out-of-control wheel is in a pressurization state, controlling the first pumping device to be opened, the wheel cylinder pressurization valve corresponding to the out-of-control wheel to be opened, the wheel cylinder pressurization valve corresponding to the wheel which is not out-of-control to be closed, and the plurality of wheel cylinder pressure relief valves to be closed;

if the out-of-control wheel is in a pressure relief state, controlling the first pumping device to be opened, the wheel cylinder pressure increase valves to be closed, the wheel cylinder pressure relief valves corresponding to the out-of-control wheel to be opened, and the wheel cylinder pressure relief valves corresponding to the wheels which are not out-of-control to be closed;

and if the out-of-control wheel is in a pressure maintaining state, controlling the first pumping device to be opened, the wheel cylinder pressure increase valves to be closed and the wheel cylinder pressure relief valves to be closed.

10. The method of braking a vehicle according to claim 5, wherein the backup braking mode includes:

it is determined whether the vehicle is unstable or not,

and if the vehicle is not unstable, entering a standby four-wheel braking mode, and if the vehicle is unstable, entering a standby single-wheel braking mode.

11. A braking method of a vehicle according to claim 10, characterized in that said standby four-wheel braking mode comprises:

determining a target braking force according to the braking demand;

controlling the second pumping device to be opened, the wheel cylinder pressure increase valves to be opened and the wheel cylinder pressure relief valves to be closed;

acquiring actual braking force of a second pumping device, and determining a target position of the second pumping device according to the actual braking force and the target braking force;

controlling the second pumping device to operate;

stopping the second pumping device if the second pumping device reaches the target position.

12. The method of braking a vehicle according to claim 10, wherein the backup single wheel braking mode includes:

determining an out-of-control wheel and a braking state of the out-of-control wheel according to the instability condition of the vehicle body;

if the out-of-control wheel is in a pressure increasing state, controlling the second pumping device to be opened, the wheel cylinder pressure increasing valve corresponding to the out-of-control wheel to be opened, the wheel cylinder pressure increasing valve corresponding to the wheel which is not out-of-control to be closed, and the plurality of wheel cylinder pressure reducing valves to be closed;

if the out-of-control wheel is in a pressure relief state, controlling the second pumping device to be opened, the wheel cylinder pressure increase valves to be closed, the wheel cylinder pressure relief valves corresponding to the out-of-control wheel to be opened, and the wheel cylinder pressure relief valves corresponding to the wheels which are not out-of-control to be closed;

and if the out-of-control wheel is in a pressure maintaining state, controlling the second pumping device to be opened, the wheel cylinder pressure increase valves to be closed and the wheel cylinder pressure relief valves to be closed.

13. A computer-readable storage medium, characterized in that a braking program is stored thereon, which when executed is processed to implement a braking method of a vehicle according to any one of claims 5-12.

14. A vehicle comprising a memory, a processor and a braking program stored on the memory and executable on the processor, the processor when executing the braking program implementing a method of braking a vehicle as claimed in any one of claims 5 to 12.

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