Failure protection system and protection method for hybrid braking system

Abstract

The invention discloses a failure protection system and method for a hybrid brake system, and the system comprises a front axle brake booster which comprises a pedal brake unit and a drive unit; the rear axle brake booster comprises rear axle brake calipers; the pedal braking unit is connected with a push rod unit and a driving unit and used for controlling braking failure protection of the front axle braking calipers and the rear axle braking calipers. When the front axle brake booster fails, a first hydraulic circuit of the front axle brake calipers is triggered through the push rod brake unit, so that hydraulic oil is input into the front axle brake calipers for braking; when the rear axle brake booster loses efficacy, a second hydraulic circuit of the rear axle brake calipers is triggered through the driving unit, and hydraulic oil is input into the rear axle brake calipers for braking; when the front axle brake booster and the rear axle brake booster both fail, the first hydraulic loop communicates with the second hydraulic loop, the front axle brake caliper and the rear axle brake caliper are braked at the same time through the push rod brake unit, and brake failure protection is achieved.

Description

A failure protection system and method for a hybrid braking system Technical Field

[0001] This invention relates to the field of automotive braking technology, and in particular to a failure protection system and method for a hybrid braking system. Background Technology

[0002] With the development of vehicle electrification and intelligence, brake-by-wire technology is gradually becoming a trend. Currently, there are two main brake-by-wire methods: one is electro-hydraulic braking (EHB), which retains the hydraulic actuator and establishes braking pressure through motor drive. It has high technological maturity, but its response speed is limited by hydraulic transmission. The other is electromechanical braking (EMB), which completely eliminates the hydraulic system and directly achieves braking through motor drive. It has a fast response speed, but is more expensive. In the event of EHB or EMB braking failure, when only the EHB system is used, failure can only rely on traditional hydraulic backup, failing to fully utilize the advantages of electronic control. When only the EMB system is used, once it fails, there is no hydraulic backup, requiring a complex mechanical backup mechanism for braking, which is costly. When EHB and EMB braking are used in combination, under extreme failure conditions, such as vehicle power failure, partial EMB failure, or CAN communication interruption, there is a safety hazard of complete loss or uncontrolled release of rear wheel braking capability. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by proposing a failure protection system and method for a hybrid braking system.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a fail-safe system for a hybrid braking system, comprising: a front axle brake booster, including a pedal brake unit and a drive unit; a rear axle brake booster, including a rear axle brake caliper; the pedal brake unit is connected to a push rod unit and the drive unit, for controlling the fail-safe protection of the front axle brake caliper and the rear axle brake caliper; when the front axle brake booster fails, the push rod brake unit triggers a first hydraulic circuit of the front axle brake caliper, causing hydraulic oil to be input into the front axle brake caliper for braking; when the rear axle brake booster fails, the drive unit triggers a second hydraulic circuit of the rear axle brake caliper, causing hydraulic oil to be input into the rear axle brake caliper for braking; when both the front axle brake booster and the rear axle brake booster fail, the first hydraulic circuit and the second hydraulic circuit are connected, and the push rod brake unit simultaneously brakes both the front axle brake caliper and the rear axle brake caliper.

[0005] As a further description of the above technical solution: the pedal braking unit includes a pedal simulator, and the output end of the pedal simulator is connected in parallel with a pedal isolation valve and a first one-way valve.

[0006] As a further description of the above technical solution: the push rod unit includes a push rod, one side of which is connected to the master cylinder piston, and the master cylinder piston is connected to the hydraulic oil tank.

[0007] As a further description of the above technical solution: the other end of the pedal isolation valve and the first one-way valve is connected to the master cylinder piston.

[0008] As a further description of the above technical solution: the drive unit includes a motor, the output end of the motor is provided with a transmission mechanism, the transmission mechanism is connected to the hydraulic oil tank through a second one-way valve; the output end of the transmission mechanism is connected to a pressure supply valve.

[0009] As a further description of the above technical solution: the first hydraulic circuit includes a circuit isolation valve, the circuit isolation valve is connected to the pedal isolation valve, and the output end of the circuit isolation valve is connected to the output end of the pressure supply valve.

[0010] As a further description of the above technical solution: the first hydraulic circuit also includes a first wheel cylinder valve, which is connected to the output end of the pressure supply valve and the circuit isolation valve, and the output end of the first wheel cylinder valve is connected to the front axle brake caliper.

[0011] As a further description of the above technical solution: the first hydraulic circuit also includes a second wheel cylinder valve, the second wheel cylinder valve is connected to the output end of the hydraulic oil tank, and the other end of the second wheel cylinder valve is connected to the front axle brake caliper.

[0012] As a further description of the above technical solution: the second hydraulic circuit includes a fail-safe backup valve, which is connected to the output end of the circuit isolation valve, and the output end of the fail-safe backup valve is connected to the rear axle brake caliper.

[0013] The system also includes a failure protection method for a hybrid braking system, comprising: acquiring the status information of the front axle brake caliper and the rear axle brake caliper; acquiring the displacement signal of the push rod unit based on the status information, determining whether a failure has occurred according to a preset detection strategy, and if not, keeping it unchanged, and if so, identifying the failure type; and, based on the failure type and the displacement signal, invoking a preset compensation control strategy to distribute the braking force of the front axle brake caliper or the rear axle brake caliper to perform brake failure protection.

[0014] The above technical solution has the following advantages or beneficial effects: This application uses a pedal braking unit, a push rod unit and a drive unit to control the braking of the front axle brake caliper and the rear axle brake caliper. When braking failure occurs, the first hydraulic circuit or the second hydraulic circuit is connected to the front axle brake caliper and the rear axle brake caliper to perform auxiliary braking and realize brake failure protection. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 is a structural principle diagram of the protection system proposed in this invention; Figure 2 is a structural schematic diagram of the rear axle brake caliper proposed in this invention; Figure 3 is a flowchart of the protection method proposed in this invention.

[0017] Legend: 1. Front axle brake caliper; 2. Rear axle brake caliper; 3. Pedal simulator; 4. Pedal isolation valve; 5. First check valve; 6. Push rod; 7. Master cylinder piston; 8. Hydraulic oil tank; 9. Motor; 10. Transmission mechanism; 11. Second check valve; 12. Pressure supply valve; 13. First wheel cylinder valve; 14. Second wheel cylinder valve; 15. Circuit isolation valve; 16. Failure backup valve; 17. Actuating caliper; 18. Hydraulic backup caliper. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Referring to Figure 1, one embodiment of the present invention provides a fail-safe system for a hybrid braking system, comprising: a front axle brake booster A, including a pedal brake unit and a drive unit; and a rear axle brake booster B, including a rear axle brake caliper 2. The pedal brake unit is connected to a push rod unit and a drive unit to control the brake fail-safe protection of the front axle brake caliper 1 and the rear axle brake caliper 2. When the front axle brake booster A fails, the push rod brake unit triggers the first hydraulic circuit of the front axle brake caliper 1, causing hydraulic oil to be input into the front axle brake caliper 1 for braking. When the rear axle brake booster B fails, the drive unit triggers the second hydraulic circuit of the rear axle brake caliper 2, causing hydraulic oil to be input into the rear axle brake caliper 2 for braking. When both the front axle brake booster A and the rear axle brake booster B fail, the first hydraulic circuit and the second hydraulic circuit are connected, and the push rod brake unit simultaneously brakes the front axle brake caliper 1 and the rear axle brake caliper 2.

[0020] In this embodiment, the front axle brake caliper 1 and the rear axle brake caliper 2 are controlled by a pedal brake unit, a push rod unit, and a drive unit. When the front axle brake booster A fails to brake, the displacement signal sent by the push rod unit is obtained, and the first hydraulic circuit or the second hydraulic circuit is connected to the front axle brake caliper 1 and the rear axle brake caliper 2 respectively, or the first hydraulic circuit is connected to the second hydraulic circuit. When the front axle brake booster A or the rear axle brake booster B fails to brake on one side, the first hydraulic circuit or the second hydraulic circuit can be controlled independently. When the front axle brake booster A or the rear axle brake booster B fails to brake on both sides, the first hydraulic circuit is connected to the second hydraulic circuit, and the push rod unit controls the front axle brake caliper 1 and the rear axle brake caliper 2 to perform auxiliary braking, thereby achieving brake failure protection.

[0021] Specifically, during normal driving braking, the front axle brake caliper 1 uses the EHB system for hydraulic braking, and the rear axle brake caliper 2 uses the hydraulically redundant EMB system for braking. The front axle brake caliper 1 and the rear axle brake caliper 2 are equipped with brake wheel cylinders. The rear axle brake caliper 2 is equipped with an EMB actuator caliper 17 and a hydraulic backup caliper 18 (see Figure 2). During normal driving braking, these can be used for EMB braking and hydraulic backup braking, respectively.

[0022] The pedal braking unit includes a pedal simulator 3, and the output end of the pedal simulator 3 is connected in parallel with a pedal isolation valve 4 and a first one-way valve 5; the other end of the pedal isolation valve 4 and the first one-way valve 5 is connected to the master cylinder piston 7.

[0023] In this embodiment, the pedal simulator 3 receives the driver's pedal operation signal and controls the hydraulic oil flow direction through the pedal isolation valve 4 and the first one-way valve 5 to avoid circuit crosstalk; the pedal simulator 3 simulates the feedback of the brake pedal to improve the driving experience.

[0024] The push rod unit includes a push rod 6, one side of which is connected to the master cylinder piston 7, and the master cylinder piston 7 is connected to the hydraulic oil tank 8.

[0025] In this embodiment, the pedal simulator 3 acquires a braking signal and simultaneously acquires a displacement signal through the push rod unit to determine whether braking failure has occurred. For example, if a braking signal is acquired but no displacement signal is received or the displacement signal is continuously changing, it indicates that braking may not have occurred or braking may have gradually failed. Based on the braking failure situation, the push rod 6 pushes the master cylinder piston 7 to draw hydraulic oil from the hydraulic oil tank 8.

[0026] The drive unit includes a motor 9, and a transmission mechanism 10 is provided at the output end of the motor 9. The transmission mechanism 10 is connected to the hydraulic oil tank 8 through a second check valve 11. The output end of the transmission mechanism 10 is connected to a pressure supply valve 12.

[0027] In this embodiment, during normal driving braking, the hydraulic oil in the hydraulic oil tank 8 is output to the pressure supply valve 12 through the second check valve 11 via the transmission mechanism 10 driven by the motor 9. The pressure supply valve 12 controls the front axle brake caliper 1 to brake through the first wheel cylinder valve 13.

[0028] The first hydraulic circuit includes a circuit isolation valve 15, which is connected to the pedal isolation valve 4. The output end of the circuit isolation valve 15 is connected to the output end of the pressure supply valve 12. The first hydraulic circuit also includes a first wheel cylinder valve 13, which is connected to the output ends of the pressure supply valve 12 and the circuit isolation valve 15. The output end of the first wheel cylinder valve 13 is connected to the front axle brake caliper 1.

[0029] In this embodiment, when the front axle brake booster A fails, the circuit isolation valve 15 is opened, the pedal isolation valve 4 and the pressure supply valve 12 are closed, and the hydraulic oil is input to the circuit isolation valve 15 through the push rod 6 and the master cylinder piston 7, and then delivered by the circuit isolation valve 15 to the first wheel cylinder valve 13. There are two first wheel cylinder valves 13, which are respectively connected to the two brake wheel cylinders of the front axle brake caliper 1 for failure braking.

[0030] The first hydraulic circuit also includes a second wheel cylinder valve 14, which is connected to the output end of the hydraulic oil tank 8, and the other end of the second wheel cylinder valve 14 is connected to the front axle brake caliper 1.

[0031] In this embodiment, the second wheel cylinder valve 14 is a normally closed valve. After the front axle brake caliper 1 finishes normal driving braking or failed braking, it is connected to the hydraulic oil tank 8, so that the hydraulic oil of the front axle brake caliper 1 can quickly flow back to the hydraulic oil tank 8 and restore the driving function.

[0032] The second hydraulic circuit includes a fail-safe backup valve 16, which is connected to the output end of the circuit isolation valve 15, and the output end of the fail-safe backup valve 16 is connected to the rear axle brake caliper 2.

[0033] In this embodiment, when the rear axle brake booster B fails, the circuit isolation valve 15 closes, the pressure supply valve 12 and the fail-safe backup valve 16 are connected, and hydraulic oil is input to the rear axle brake caliper 2 through the pressure supply valve 12 and the fail-safe backup valve 16 to perform fail-safe braking.

[0034] When both the front axle brake booster A and the rear axle brake booster B fail, the first wheel cylinder valve 13 and the fail-safe backup valve 16 are connected, while the pedal isolation valve 4, the pressure supply valve 12, and the second wheel cylinder valve 14 are disconnected, allowing hydraulic oil to enter the front axle brake caliper 1 and the rear axle brake caliper 2 from the master cylinder piston 7 through the circuit isolation valve 15, the first wheel cylinder valve 13, and the fail-safe backup valve 16 for fail-safe braking.

[0035] Referring to Figure 3, a failure protection method for a hybrid braking system is also included, comprising: S1, acquiring the status information of the front axle brake caliper and the rear axle brake caliper; S2, based on the status information, acquiring the displacement signal of the push rod unit, and determining whether a failure has occurred according to a preset detection strategy; if not, it remains unchanged; if so, the failure type is identified; S3, based on the failure type and the displacement signal, calling a preset compensation control strategy to distribute the braking force of the front axle brake caliper or the rear axle brake caliper to perform brake failure protection.

[0036] In this embodiment, the status information of the front axle brake caliper and the rear axle brake caliper is acquired. The braking signal is used to determine whether the vehicle is in a normal driving state or in a braking state. At the same time, the displacement information of the push rod is acquired. According to the preset detection strategy, it is determined whether a failure has occurred. The detection strategy periodically performs sensor and communication fault detection, actuator performance detection and vehicle dynamics state assessment according to the preset time period to determine whether a single-sided failure or a complete failure of the front axle brake booster A and the rear axle brake booster B has occurred.

[0037] When the front axle brake booster A fails, the front axle brake caliper is assisted in braking control through the first hydraulic circuit, and a preset compensation control strategy is invoked. The compensation control strategy includes: calculating the actual available braking force (hydraulic oil pressure) of the front axle brake caliper, transferring the insufficient part to the rear axle brake caliper, performing differential control through the left and right EMBs of the rear axle brake caliper, adjusting the ABS intervention threshold to prevent the rear axle brake caliper from locking up first, so that the vehicle as a whole can perform stable braking control.

[0038] When the rear axle brake booster B fails, the second hydraulic circuit assists the rear axle brake caliper in braking control and invokes a preset compensation control strategy. The compensation control strategy includes: detecting that the front axle brake caliper pressure has increased to the safety limit, dynamically adjusting the upper limit of the braking force of the front axle brake caliper based on the vehicle speed, activating ABS control to prevent the front axle brake caliper from locking up, and activating braking force pulse modulation to optimize the braking performance of the front axle brake caliper.

[0039] Furthermore, it also includes a failure prediction function: based on historical braking data, a performance degradation model is established, which can use neural network models or machine learning models to evaluate the health status of the hybrid braking system in real time, predict potential failure risks, adjust control parameters in advance, and prevent sudden failures.

[0040] It also includes a computer-readable storage medium storing a computer program for running the protection method, wherein the computer program causes the computer to perform the following steps: S1, acquiring the status information of the front axle brake caliper and the rear axle brake caliper; S2, based on the status information, acquiring the displacement signal of the push rod unit, determining whether a failure has occurred according to a preset detection strategy, if not, remaining unchanged, if yes, identifying the failure type; S3, based on the failure type and the displacement signal, invoking a preset compensation control strategy to distribute the braking force of the front axle brake caliper or the rear axle brake caliper to perform brake failure protection.

[0041] The computer-readable storage medium can be a computer storage medium or a communication medium. A communication medium includes any medium that facilitates the transfer of a computer program from one location to another. A computer storage medium can be any available medium accessible to a general-purpose or special-purpose computer. For example, a computer-readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the computer-readable storage medium. Of course, the computer-readable storage medium can also be a component of the processor. The processor and the computer-readable storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the ASIC can reside in a user equipment. Of course, the processor and the computer-readable storage medium can also exist as discrete components in a communication device.

[0042] Specifically, the computer-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random-Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The storage medium can be any available medium accessible to general-purpose or special-purpose computers.

[0043] It also includes an electronic device comprising: one or more processors; a memory; and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the programs being used to perform the following steps: S1, acquiring the status information of the front axle brake caliper and the rear axle brake caliper; S2, based on the status information, acquiring the displacement signal of the push rod unit, determining whether a failure has occurred according to a preset detection strategy, if not, remaining unchanged, if yes, identifying the failure type; S3, based on the failure type and the displacement signal, invoking a preset compensation control strategy to distribute the braking force of the front axle brake caliper or the rear axle brake caliper, performing brake failure protection.

[0044] Memory is used to store computer programs. This memory may include high-speed random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage device, and may also be a USB flash drive, external hard drive, read-only memory, disk or optical disc, etc.

[0045] A processor is used to execute computer programs stored in memory. The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. A general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly manifested as execution by a hardware processor, or execution by a combination of hardware and software modules within the processor.

[0046] Alternatively, the memory can be either standalone or integrated with the processor.

[0047] When memory is a device independent of the processor, electronic devices may also include a bus. This bus is used to connect the memory and the processor. This bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc.

[0048] It should be noted that, through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the prior art, can be embodied in the form of software products. These computer software products can be stored in computer-readable storage media, such as ROM / RAM, magnetic disks, optical disks, etc., and include several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or certain portions of the embodiments. In this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. In the absence of further restrictions, an element defined by the phrase "comprising a..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0049] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A fail-safe system for a hybrid braking system, characterized in that, include: The front axle brake booster (A) includes a pedal brake unit and a drive unit; Rear axle brake booster (B), including rear axle brake caliper (2); The pedal braking unit is connected to the push rod unit and the drive unit to control the brake failure protection of the front axle brake caliper (1) and the rear axle brake caliper (2). When the front axle brake booster (A) fails, the push rod braking unit triggers the first hydraulic circuit of the front axle brake caliper (1) to input hydraulic oil into the front axle brake caliper (1) for braking. When the rear axle brake booster (B) fails, the drive unit triggers the second hydraulic circuit of the rear axle brake caliper (2) to input hydraulic oil into the rear axle brake caliper (2) for braking. When both the front axle brake booster (A) and the rear axle brake booster (B) fail, the first hydraulic circuit is connected to the second hydraulic circuit, and the push rod braking unit simultaneously brakes the front axle brake caliper (1) and the rear axle brake caliper (2).

2. The protection system according to claim 1, characterized in that: The pedal braking unit includes a pedal simulator (3), and the output end of the pedal simulator (3) is connected in parallel with a pedal isolation valve (4) and a first one-way valve (5).

3. The protection system according to claim 2, characterized in that: The push rod unit includes a push rod (6), one side of which is connected to the master cylinder piston (7), and the master cylinder piston (7) is connected to the hydraulic oil tank (8).

4. The protection system according to claim 3, characterized in that: The other end of the pedal isolation valve (4) and the first one-way valve (5) is connected to the master cylinder piston (7).

5. The protection system according to claim 3, characterized in that: The drive unit includes a motor (9), and the output end of the motor (9) is provided with a transmission mechanism (10). The transmission mechanism (10) is connected to the hydraulic oil tank (8) through a second check valve (11). The output end of the transmission mechanism (10) is connected to a pressure supply valve (12).

6. The protection system according to claim 5, characterized in that: The first hydraulic circuit includes a circuit isolation valve (15), which is connected to the pedal isolation valve (4), and the output end of the circuit isolation valve (15) is connected to the output end of the pressure supply valve (12).

7. The protection system according to claim 6, characterized in that: The first hydraulic circuit also includes a first wheel cylinder valve (13), which is connected to the output end of the pressure supply valve (12) and the circuit isolation valve (15), and the output end of the first wheel cylinder valve (13) is connected to the front axle brake caliper (1).

8. The protection system according to claim 6, characterized in that: The first hydraulic circuit also includes a second wheel cylinder valve (14), which is connected to the output end of the hydraulic oil tank (8), and the other end of the second wheel cylinder valve (14) is connected to the front axle brake caliper (1).

9. The protection system according to claim 8, characterized in that: The second hydraulic circuit includes a fail-safe backup valve (16), which is connected to the output end of the circuit isolation valve (15) and the output end of the fail-safe backup valve (16) is connected to the rear axle brake caliper (2).

10. A failure protection method for a hybrid braking system, characterized in that, include: Obtain the status information of the front axle brake caliper and the rear axle brake caliper; Based on the state information, the displacement signal of the push rod unit is obtained, and a failure is determined according to the preset detection strategy. If no failure occurs, the position remains unchanged; if so, the failure type is identified. Based on the failure type and the displacement signal, a preset compensation control strategy is invoked to distribute the braking force of the front axle brake caliper or the rear axle brake caliper to perform brake failure protection.

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