Vehicle brake system and vehicle braking method

Abstract

The application relates to a vehicle braking system comprising a BWA module and an ESP module, the BWA module comprising an actuator motor, an actuator, a master cylinder, a reservoir, a master cylinder port in communication with the master cylinder, a reservoir port in communication with the reservoir, and a first control unit in communication with a pedal sensor and for controlling the actuator motor; the ESP module comprising a wheel cylinder port, a liquid inlet port in communication with the master cylinder port, a liquid outlet port in communication with the reservoir port, a liquid supply line in communication with the wheel cylinder port, the liquid inlet port and provided with a system pressure valve, a liquid discharge line in communication with the wheel cylinder port, the liquid outlet port, a liquid make-up line in communication with the liquid supply line and the liquid discharge line and provided with a pump, a pump motor, and a second control unit in communication with the first control unit and for controlling the pump motor. The application also relates to a vehicle braking method using the system.

Description

Technical Field

[0001] This application relates to a vehicle braking system and a vehicle braking method performed using the vehicle braking system. Background Technology

[0002] Currently, an exemplary configuration of a vehicle braking system includes a Brake-by-Wire (BWA) module and an Electronic Stability Program (ESP) module. The BWA module is associated with the vehicle's brake pedal to receive braking requests and primarily includes a master cylinder, an actuator that drives the master cylinder, an actuator motor that controls the actuator, and a reservoir connected to the master cylinder. The ESP module includes a supply line and a drain line connecting the vehicle's wheel cylinders and the master cylinder of the BWA module, respectively, to supply pressurized brake fluid from the master cylinder to the wheel cylinders and to return brake fluid released from the wheel cylinders to the master cylinder. Summary of the Invention

[0003] The purpose of this application is to provide an improved vehicle braking system and a corresponding vehicle braking method.

[0004] The first aspect of this application provides a vehicle braking system, comprising: a pedal sensor for a vehicle's brake pedal, the pedal sensor including a pedal force sensor and / or a pedal travel sensor; a BWA module, comprising: an actuator motor, an actuator driven by the actuator motor, a brake master cylinder driven by the actuator, a accumulator communicating with the brake master cylinder, a master cylinder port communicating with the brake master cylinder, a accumulator port communicating with the accumulator, a master cylinder sensor for measuring the real-time pressure of the brake master cylinder, and a first control unit communicatively connected to the pedal sensor and for controlling the actuator motor of the BWA module; and an ESP module, comprising: configured for connecting... The system includes a wheel cylinder port connected to the vehicle's brake wheel cylinder, an inlet port connected to the master cylinder port, a drain port connected to the reservoir port, a supply line connecting the wheel cylinder port's inlet valve and the inlet port and equipped with a system pressure valve, a drain line connecting the wheel cylinder port's outlet valve and the drain port, a replenishment line for a pump that allows brake fluid to flow only from the drain line to the main section of the supply line between the system pressure valve and the inlet valve, a pump motor that drives the pump, and a second control unit that is communicatively connected to both the pedal sensor and the first control unit and is used to control the pump motor of the ESP module.

[0005] The second aspect of this application provides a vehicle braking method using the aforementioned vehicle braking system, comprising: a first step of obtaining a braking request; a second step of obtaining information on whether the actuator motor of the BWA module and the pump motor of the ESP module are functioning normally; a third step of, if at least one of the actuator motor of the BWA module and the pump motor of the ESP module is functioning normally, selecting an appropriate fluid supply scheme based on the information obtained in the second step to supply brake fluid to the main section of the fluid supply line of the ESP module; and a fourth step of supplying the brake fluid in the fluid supply line of the ESP module obtained in the third step to the brake wheel cylinder to increase the brake fluid pressure in the brake wheel cylinder, wherein the fourth step comprises: if each solenoid valve of the ESP module is functioning normally, performing a wheel cylinder decompression operation to discharge the brake fluid in the brake wheel cylinder to the reservoir of the BWA module via the drain line of the ESP module.

[0006] A third aspect of this application provides a BWA module for the aforementioned vehicle braking system, comprising a module housing and one or two master cylinder ports disposed on the module housing, communicating with one or two master cylinder chambers of the brake master cylinder, and one or two reservoir ports communicating with one or two reservoir spaces of the reservoir, wherein the actuator motor, the actuator, the brake master cylinder, and the reservoir are all disposed within the module housing.

[0007] The fourth aspect of this application provides an ESP module for the aforementioned vehicle braking system, comprising a module housing and disposed on the module housing: four wheel cylinder ports, one or two drain ports, and one or two inlet ports, wherein the system pressure valve, the fluid supply line, the drain line, the replenishment line, the pump, and the pump motor are all disposed within the module housing.

[0008] The vehicle braking system provided in this application includes a pedal sensor (pedal force sensor and / or pedal travel sensor) for the brake pedal of a vehicle, a BWA module, and an ESP module. The BWA module includes a first ECU1 communicatively connected to the pedal sensor, an actuator motor controlled by the first ECU1, an actuator driven by the actuator motor, a brake master cylinder driven by the actuator, and a accumulator connected to the brake master cylinder. It has a master cylinder port (the number of which corresponds to the number of chambers in the brake master cylinder) connected to the brake master cylinder to output brake fluid, and a accumulator port connected to the accumulator to allow brake fluid released from the brake wheel cylinder to return to the accumulator. The ESP module includes a second ECU2 communicatively connected to both the first ECU1 and the pedal sensor; a pump motor controlled by the second ECU2; a pump driven by the pump motor; an inlet port connected to the master cylinder port of the BWA module; a drain port connected to the reservoir port of the BWA module; four wheel cylinder ports configured to connect to the four brake wheel cylinders of the vehicle; a supply line with a system pressure valve connected to the inlet valve of the wheel cylinder port; and a drain line connecting the outlet valve of the wheel cylinder port to the drain port. The pump inlet is connected to the drain line, and the outlet is connected to the main section of the supply line located between the system pressure valve and the inlet valve. This configuration of the vehicle braking system ensures that during the decompression phase of the brake wheel cylinders during normal anti-lock braking (ABS) braking, brake fluid released from the brake wheel cylinders returns to the reservoir via the drain line of the ESP module, rather than the master cylinder. This configuration reduces the load on the master cylinder and lowers the performance requirements on the actuators and actuator motors.

[0009] A vehicle braking method using the vehicle braking system of this application is also provided. According to the method of this application, after receiving a braking request, the method first determines, based on a comparison between the demand pressure calculated based on the braking request and the pre-set warning pressure value and limit pressure value for the master cylinder, whether the braking process to be implemented will execute a first supply scheme STR1 (supplying fluid from the master cylinder to the wheel cylinders) or a second supply scheme STR2 (supplying fluid first in the master cylinder supply mode, then in a transitional supply mode (supplying fluid from the master cylinder and the pump / reservoir simultaneously) or a third supply scheme STR3 (supplying fluid first in the master cylinder supply mode, then transitioning to an ESP supply mode (supplying fluid solely by the refrigeration unit) via a transitional supply mode (supplying fluid from the master cylinder and the pump / reservoir simultaneously)).

[0010] The second fluid supply scheme of this application has advantages. At this time, the demand pressure is between the warning pressure value and the limit pressure value. When the master cylinder can provide the demand pressure, the ESP module is still activated to draw brake fluid from the reservoir to supply the main section of the fluid supply line. The purpose is to be ready to deal with the situation where the demand pressure exceeds the limit pressure value of the master cylinder, so that once the situation occurs, the vehicle braking process can transition to the ESP fluid supply mode in a timely and smooth manner.

[0011] The third fluid supply scheme of this application also has advantages. On the one hand, setting a transitional fluid supply mode can effectively overcome the disadvantages of large net boost amplitude and long response time that occur during the transition from the master cylinder fluid supply mode with fast boost speed but low maximum boost pressure to the ESP fluid supply mode with high maximum boost pressure but slow boost speed. On the other hand, the comparison between the real-time pressure of the master cylinder measured by the master cylinder sensor and the limit pressure value and warning pressure value of the brake master cylinder can determine when to activate the pump motor of the ESP module to start and end the transitional fluid supply mode, and during the final ESP fluid supply mode, the control or regulation of the pump outlet pressure (i.e., the pressure on the main section of the fluid supply line of the ESP module) is performed based on the comparison between the real-time pump pressure or real-time deceleration measured by the pump sensor or deceleration sensor and the master cylinder target pressure or vehicle target deceleration. Attached Figure Description

[0012] The foregoing and other features and advantages of this application will be readily understood upon reading the following detailed description with reference to the accompanying drawings.

[0013] Figure 1 This is a hydraulic wiring diagram of a vehicle braking system according to a first exemplary configuration of this application.

[0014] Figure 2 This is a hydraulic wiring diagram of a vehicle braking system according to a second exemplary configuration of this application.

[0015] Figure 3 This is a hydraulic wiring diagram of a vehicle braking system according to a third exemplary configuration of this application.

[0016] Figure 4 This is a hydraulic wiring diagram of a vehicle braking system according to the fourth exemplary configuration of this application.

[0017] Figure 5 Show Figure 1 Hydraulic circuit diagram of the vehicle braking system in master cylinder supply mode (M1) or transitional supply mode (M2).

[0018] Figure 6The diagram shows the hydraulic circuitry of the vehicle braking system in ESP fluid supply mode (M3) and the control of the pump outlet pressure of the ESP module (i.e., the pressure on the main section of the fluid supply line of the ESP module) in either the boost (M30.2) or the first pressure holding operation (M30.1) of the control cycle (M30).

[0019] Figure 7 The diagram shows the hydraulic circuitry when the vehicle braking system is in ESP fluid supply mode (M3) and the control of the pump outlet pressure of the ESP module is in either the pressure reduction operation (M30.3) or the second pressure holding operation (M30.1) of the control cycle (M30).

[0020] Figure 8 A flowchart of a vehicle braking method performed using the vehicle braking system of this application.

[0021] Figure 9 for Figure 8 The steps of the first case in the third step of the vehicle braking method.

[0022] Figure 10a In order to be in Figure 9 The flowchart of the fourth sub-step S318 in which the vehicle braking system executes the first pressure control cycle (M10) in master cylinder fluid supply mode (M1).

[0023] Figure 10b In order to be in Figure 9 The flowchart of the seventh sub-step S315, in which the vehicle braking system executes the first pressure control cycle (M10) or the second pressure control cycle (M20) with the second fluid supply scheme (STR2) consisting of the master cylinder fluid supply mode (M1) and the transition fluid supply mode (M2).

[0024] Figure 10c for Figure 9 The flowchart of the ninth sub-step S319.

[0025] Figure 11 for Figure 8 The steps of the second case in the third step of the vehicle braking method.

[0026] Figure 12a For the vehicle braking system configured by the first and third examples Figure 8 The steps of the third case in the third step of the vehicle braking method.

[0027] Figure 12b For the vehicle braking system configured as the second and fourth examples Figure 8 The steps of the third case in the third step of the vehicle braking method. Detailed Implementation

[0028] Appendix Figure 1-4 Four exemplary configurations of the vehicle braking system of this application are illustrated. Generally, the vehicle braking system of this application includes a brake pedal (hereinafter referred to as BP) module 10, a drive-by-wire actuator (hereinafter referred to as BWA) module 100 associated with the BP module 10, and an electronic stability program (hereinafter referred to as ESP) module 200 connected to both the BWA module 100 and the respective brake wheel cylinders WC1 / 2 / 3 / 4 of the vehicle to enable fluid communication between the two.

[0029] The BWA module 100 and BP module 10 of the vehicle braking system are connected via electrical signals, not mechanical connections. Since there is no mechanical connection between the BP module 10 and both the BWA module 100 and ESP module 200, the vehicle braking system of this application also includes an electronic parking brake (EPB) module capable of braking independently of the BWA module 100 and ESP module 200 in situations such as: when the vehicle is not started and therefore the electronic components of the vehicle braking system are not powered; or when both the BWA module 100 and ESP module 200 fail in an emergency. Figure 1-4 Of the four exemplary configurations shown, EPB2 and EPB4 are mounted in relation to brake calipers of wheels (e.g., two rear wheels) corresponding to two brake wheel cylinders WC2 / 4.

[0030] The following is a reference to the appendix. Figure 1 The first exemplary configuration of the vehicle braking system described in this application is described in detail.

[0031] The BP module 10 of the vehicle braking system includes a brake pedal BP and a brake feel simulator PFS associated with the brake pedal BP, and also includes a pedal sensor containing one or two of the following: a pedal force sensor PFT for measuring the force acting on the brake pedal BP, and a pedal travel sensor PST for measuring the travel of the brake pedal BP when it is depressed.

[0032] The BWA module 100 of the vehicle braking system mainly includes: a accumulator RSV, which may, but is not necessarily, limited to two storage spaces RSV1 and RSV2; a dual-chamber brake master cylinder TMC, including two pistons H1 and H2 and two master cylinder chambers MC1 and MC2; an actuator AT; and an actuator motor AM. The BWA module 100 has four ports disposed on the module housing: two master cylinder ports Pt_MC1 / 2 and two accumulator ports Pt_RSV1 / 2. The master cylinder ports Pt_MC1 / 2 are respectively connected to the master cylinder chambers MC1 and MC2 of the brake master cylinder MC via master cylinder lines C_MC1 / 2. The accumulator ports Pt_RSV1 / 2 are respectively connected to the storage spaces RSV1 and RSV2 of the accumulator RSV via accumulator lines C_RSV1 / 2. The master cylinder sensor PS_MC is used to measure the output pressure of the brake master cylinder MC (either chamber, such as the first chamber MC1), and it can be disposed on any one of the master cylinder lines C_MC1 / 2 (e.g., C_MC1).

[0033] The ESP module 200 of the vehicle braking system includes eight ports disposed on the module housing: two drain ports Pt_PE1 / 2, two inlet ports Pt_SC1 / 2, and four wheel cylinder ports Pt_WC1 / 2 / 3 / 4 for connection to the four wheel cylinders WC1 / 2 / 3 / 4 of the vehicle. The two inlet ports Pt_SC1 / 2 are connected, for example, to the master cylinder port Pt_MC1 / 2 of the BWA module 100 via external piping T_MC1 / 2, and to the inlet valves IV1 / 2 / 3 / 4 of the four wheel cylinder ports Pt_WC1 / 2 / 3 / 4 via internal fluid supply lines within the ESP module 200, thereby supplying brake fluid received from the master cylinder MC of the BWA module 100 to the wheel cylinders WC1 / 2 / 3 / 4. The two drain ports Pt_PE1 / 2 are connected, for example, to the accumulator port Pt_RSV1 / 2 of the BWA module 100 via external pipeline T_RSV1 / 2, and to the outlet valves OV1 / 2 / 3 / 4 of the four wheel cylinder ports Pt_WC1 / 2 / 3 / 4 via the drain line inside the ESP module 200, thereby allowing the brake fluid released from the brake cylinders WC1 / 2 / 3 / 4 to be discharged into the accumulator RSV of the BWA module 100.

[0034] The fluid supply line is equipped with a system pressure valve SC1 / 2, thus dividing it into a system segment C_SC1 / 2 between the inlet port Pt_SC1 / 2 and the system pressure valve SC1 / 2, and a main segment C_Pri1 / 2 between the system pressure valve SC1 / 2 and the inlet valves IV1 / 2 / 3 / 4. Pump PE1 / 2, driven by pump motor PM, allows unidirectional connection between the drain line and the main segment C_Pri1 / 2 of the supply line, forming a compensation line that allows brake fluid from the drain line to compensate for brake fluid in the supply line, but prohibits brake fluid from the supply line from entering the drain line. The inlet of pump PE1 / 2 is connected to the drain line, and thus to the reservoir RSV of the BWA module 100 located above pump PE1 / 2 (specifically, the two pumps are connected to two reservoirs RSV1 and RSV2 respectively), enabling the extraction and pressurization of brake fluid from these reservoirs to supply it to the main segment C_Pri1 / 2 of the supply line. The ESP module 200 may also include a pressure sensor PS_PE located on the main section C_Pri1 / 2 of the fluid supply line. In the ESP fluid supply mode described below, the pressure measured by this pressure sensor is equal to the pressure at the outlet side of pump PE1 / 2, i.e., the pump's output pressure; therefore, this sensor is also called a pump sensor. Since the system section C_SC1 / 2 of the fluid supply line is connected to the master cylinder line C_MC1 / 2 of the BWA module 100, in the master cylinder fluid supply mode described below, the pressure measured by the master cylinder sensor PS_MC is the brake fluid pressure on the system section C_SC1 / 2 of the fluid supply line. The ESP module 200 may not require a separate pressure sensor on the system section C_SC1 / 2 of the fluid supply line (i.e., upstream of the system pressure valve SC1 / 2).

[0035] The BWA module 100 and ESP module 200 of the vehicle braking system of this application are further provided with BWA module control unit ECU1 and ESP module control unit ECU2 (hereinafter referred to as first ECU1 and second ECU2), respectively. They may each have a power supply battery Bat1 / 2, and the two are communicatively connected to each other. Both are communicatively and electrically connected to wheel speed sensors WSS1 / 2 / 3 / 4 mounted on the wheels. Both first ECU1 and second ECU2 are communicatively and electrically connected to the pedal sensor of BP module 10 (communication connections S1 and S2, power connections P1 and P2 and ground connections G1 and G2 are shown in the figure), so that when the brake pedal BP is depressed, first ECU1 and / or second ECU2 can receive a braking request in the form of an electrical signal from the pedal sensor. One of first ECU1 and second ECU2 (e.g., second ECU2) is also provided with a deceleration sensor aS, and the other of first ECU1 and second ECU2 is communicatively connected to deceleration sensor aS.

[0036] As a variation, Figure 2 The second exemplary configuration differs from Figure 1 The first exemplary configuration is only in Figure 2 The ESP module 200 in the system does not set the pump sensor PS_PE.

[0037] Figure 3 and 4 The third and fourth exemplary configurations differ from Figure 1 and 2 The first and second exemplary configurations are characterized in that a single-chamber brake master cylinder MC, comprising only one master cylinder chamber, is used instead of... Figure 1 and 2 The dual-chamber brake master cylinder TMC is described. Correspondingly, the BWA module 100 includes only one master cylinder port Pt_MC (three ports in total on the module housing), and a master cylinder line C_MC connecting the master cylinder port Pt_MC to the master cylinder chamber MC; and correspondingly, the ESP module 200 has only one fluid inlet port Pt_SC (seven ports in total on the module housing), through which brake fluid enters the supply line leading to each pair of brake wheel cylinders, supplying brake fluid to all four brake wheel cylinders.

[0038] The following is for reference. Figure 1 The first exemplary configuration of the vehicle braking system describes its braking process in detail. Figure 5-7 The thick solid line represents the brake fluid circuit section mentioned in this manual.

[0039] The first and second ECUs 1 and ECU 2 of the BWA module 100 and ESP module 200 of the vehicle braking system can only receive braking requests in the form of electrical signals. Therefore, the vehicle braking system can only perform the braking process in response to receiving a vehicle braking request (such as the brake pedal BP being pressed or other braking requests in the form of electrical signals) when the vehicle is ignited (all electrical components are powered on) and at least one of the actuator motor AM and pump motor PM is in normal working condition.

[0040] When all components of the vehicle's braking system are functioning normally, for example, under anti-lock braking (ABS) conditions, the braking process is first executed in master cylinder fluid supply mode M1, such as... Figure 5 As shown. In particular, the master cylinder fluid supply mode M1 is used when the real-time pressure P_act_MC of the master cylinder measured by the master cylinder sensor PS_MC is less than the preset warning pressure value P_alt_MC of the brake master cylinder TMC.

[0041] Specifically, the first ECU1 of the BWA module 100 receives a signal indicating a braking request from the pedal sensor (PFT and / or PST) and controls the actuator motor AM to rotate. Then, the actuator AT drives the pistons H1 and H2 of the master cylinder TMC to move forward. The brake fluid pressurized in each brake chamber MC1 and MC2 of the master cylinder TMC is supplied to the wheel cylinder port Pt_WC1 / 2 / 3 / 4 (inlet valve IV1 / 2 / 3 / 4) of the ESP module 200 via the master cylinder line C_MC1 / 2 of the BWA module 100, the external line T_MC1 / 2, and the fluid supply line (C_SC1 / 2+C_Pri1 / 2) of the ESP module 200. Finally, it is supplied to the wheel cylinder WC1 / 2 / 3 / 4 to establish or maintain braking pressure in the wheel cylinder. When the brake fluid is released by depressurizing the wheel cylinders, the released brake fluid is discharged back to the accumulator RSV via the OV1 / 2 / 3 / 4 lines connected by the ESP module 200 and the drain line. This completes a "braking cycle" that includes wheel cylinder pressurization, wheel cylinder pressure holding, and wheel cylinder depressurization. The anti-lock braking process involves repeating this braking cycle.

[0042] As mentioned above, during the decompression operation of the braking cycle in the vehicle braking system of this application, the brake fluid with pressure fluctuations in the brake wheel cylinders is discharged back to the accumulator RSV via the drain line of the ESP module 200, instead of the master cylinder MC. This provides higher vehicle NVH performance, offering a better driving experience for the driver, while reducing the load on the BWA module 100 and improving its reliability and economy. The ESP module 200 of the vehicle braking system of this application does not require a low-pressure accumulator, nor does it require a normally closed high-pressure switching valve (HSV) or other hydraulic components, simplifying the configuration of the compensation fluid supply line of the ESP module 200, saving costs to some extent, and eliminating related noise.

[0043] During the braking of the brake wheel cylinder in the master cylinder supply mode M1, the first ECU1 of the BWA module 100 controls the pressure in the master cylinder line C_MC1 / 2 by controlling the actuator motor AM. This pressure is equal to the master cylinder output pressure measured by the master cylinder sensor PS_MC and equal to the brake fluid pressure in the supply line of the ESP module 200.

[0044] The control of the pressure in the master cylinder line C_MC1 / 2 executed by the first ECU1 of the BWA module 100 includes repeatedly executing a "control cycle" consisting of a pressurization operation M10.2 that increases the pressure in the master cylinder line C_MC1 / 2, a pressure holding operation M10.1 that maintains the pressure in the master cylinder line C_MC1 / 2, and a pressure reduction operation M10.3 that decreases the pressure in the master cylinder line C_MC1 / 2. Specifically, the pressure boosting operation M10.2 is achieved by the first ECU1 controlling the actuator motor AM to rotate forward (clockwise or counterclockwise), thereby causing the actuator AT to move the pistons H1 and H2 of the master cylinder TMC forward (increasing the brake fluid pressure in the master cylinder chamber); the pressure holding operation M10.1 is achieved by the first ECU1 controlling the actuator motor AM to stop rotating, thereby preventing the pistons H1 and H2 of the master cylinder TMC from moving; the pressure reducing operation M10.3 is achieved by the first ECU1 controlling the actuator motor AM to rotate in the reverse direction (counterclockwise or counterclockwise), thereby causing the pistons H1 and H2 of the master cylinder TMC to move backward (reducing the brake fluid pressure in the master cylinder chamber).

[0045] The process of executing this control cycle is called the first pressure control cycle M10, such as... Figure 5 As shown. During this process, the second ECU2 of the ESP module 200 and the pump motor PM are not working, and all electrical components of the ESP module 200 (such as the system pressure valves SC1 / 2 in the fluid supply line) remain de-energized. Therefore, in addition to the condition that all modules / components of the entire system are working normally, this master cylinder fluid supply mode M1 and this first pressure control cycle M10 can also be performed if the ESP module 200 fails (for example, if the pump motor PM and / or the second ECU2 fails to control the pump motor PM).

[0046] The vehicle braking system of this application also provides a transitional fluid supply mode M2 ​​for use during the period when the real-time pressure P_act_MC of the master cylinder is between the aforementioned warning pressure value P_alt_MC and a preset limit pressure value P_lmt_MC greater than the warning pressure value P_alt_MC. The hydraulic circuit diagram remains the same. Figure 5 .

[0047] In the transitional fluid supply mode M2, on one hand, the first ECU1 of the BWA module 100 controls the actuator motor AM to rotate forward, and the brake fluid pressurized in the master cylinder TMC is supplied to the main section C_Pri1 / 2 of the fluid supply line via the system pressure valve SC1 / 2 of the ESP module 200; on the other hand, the second ECU2 of the ESP module 200 controls the pump motor PM to rotate, and the pump PE1 / 2 draws brake fluid from the reservoir RSV and supplies it to the main section C_Pri1 / 2 of the fluid supply line after pressurization. Both portions of brake fluid are simultaneously supplied to the wheel cylinders WC1 / 2 / 3 / 4 via the wheel cylinder ports Pt_WC1 / 2 / 3 / 4. During this mode M2, the control of the actuator motor AM by the first ECU1 of the BWA module 100 and the control of the pump motor PM by the second ECU2 of the ESP module 200 are carried out simultaneously and in coordination, jointly executing the second pressure control cycle M20 to control the pressure in the main section C_Pri1 / 2 of the fluid supply line of the ESP module 200. The second pressure control cycle M20 includes: a boosting operation M20.2, in which the first ECU1 controls the actuator motor AM to rotate forward or stop rotating, thus the actuator AT drives the piston of the master cylinder to move forward or stop to increase or maintain the pressure in the master cylinder line C_MC1 / 2, while the second ECU2 controls the pump motor PM to rotate, thereby driving the pump PE1 / 2 to draw brake fluid from the reservoir RSV, pressurize it, and replenish it to the main section C_Pri1 / 2 of the fluid supply line to increase the pressure in the main section C_Pri1 / 2; and a pressure holding operation M20.1, in which the first ECU1 controls the actuator motor AM to rotate in the opposite direction by a certain angle, thus the actuator AM controls... The piston of the brake master cylinder retracts a certain distance to reduce the pressure in the master cylinder circuit C_MC1 / 2. At the same time, the second ECU2 controls the pump motor PM to rotate, thereby driving the pump PE1 / 2 to compensate for the pressure loss in the main circuit C_Pri1 / 2 (due to the pressure reduction in the master cylinder circuit C_MC1 / 2). Pressure reduction operation M20.3, in which the second ECU2 controls the pump motor PM to keep or stop rotating, thereby making the pump PE1 / 2 work or not work. At the same time, the first ECU1 controls the actuator motor AM to rotate in the opposite direction, so the actuator AM controls the piston of the brake master cylinder to retract to reduce the pressure in the master cylinder circuit C_MC1 / 2 and the main circuit C_Pri1 / 2.

[0048] The vehicle braking system of this application also provides an ESP fluid supply mode M3, which occurs when the real-time pressure P_act_MC of the master cylinder has reached the limit pressure value P_lmt_MC, but is still insufficient to provide the required pressure to meet the braking demand, and is therefore executed after the transition fluid supply mode M2.

[0049] At this point, the master cylinder real-time pressure P_act_MC has reached the limit pressure value P_lmt_MC. The first ECU1 controls the actuator motor AM to stop rotating, and the brake master cylinder TMC can no longer supply brake fluid. At this time, the second ECU2 of the ESP module 200 continues to control the system pressure valve SC1 / 2 to disconnect and controls the pump motor PM and pump PE1 / 2 to continue working. That is, in ESP fluid supply mode M3, the braking process transitions to only pressurizing and supplying brake fluid drawn from the reservoir RSV to the main section C_Pri1 / 2 of the fluid supply line.

[0050] At this time, the second ECU2 of the ESP module 200 controls the output pressure of the pump PE1 / 2, that is, the pressure on the main section C_Pri1 / 2 of the liquid supply line, by controlling the rotation of the pump motor PM. This pressure is the pressure measured by the pump sensor PS_PE.

[0051] During ESP fluid supply mode M3, the second ECU2 of ESP module 200 controls the third pressure cycle M30 of the pump output pressure (pressure on the main section C_Pri1 / 2 of the fluid supply line), which includes multiple boosting operations M30.2 that increase the pump output pressure (such as...). Figure 6 As shown), the pressure holding operation M30.1 maintains the pump output pressure (as shown). Figure 6 or Figure 7 As shown), the pressure reduction operation M30.3 reduces the pump output pressure (as shown). Figure 7 The control loop is as shown. Specifically, the boosting operation M30.2 controls the system pressure valve SC1 / 2 to be energized and de-energized by the second ECU2, and controls the pump motor PM to rotate. Therefore, the pump PE1 / 2 draws brake fluid from the reservoir RSV, pressurizes it, and supplies it to the main section C_Pri1 / 2 of the fluid supply line. The pressure holding operation M30.1 controls the system pressure valve SC1 / 2 to have a certain opening degree by the second ECU2 in pulse width modulation mode. Figure 7 ) or power on / off ( Figure 6 And control the pump motor PM to rotate or stop rotating, thereby driving or stopping the pump PE1 / 2 to compensate (such as Figure 7 (As shown) Pressure loss in the main road section C_Pri1 / 2 (due to the certain opening of the system pressure valve SC1 / 2) or maintenance (such as...) Figure 6 (As shown) The pressure in the main road section C_Pri1 / 2 is reduced; the pressure reduction operation M30.3 controls the system pressure valve SC1 / 2 to a certain opening degree through the second ECU2 in pulse width modulation mode, and controls the pump motor PM to rotate or stop rotating, thereby driving or stopping the pump PE1 / 2 to reduce the pressure in the main road section C_Pri1 / 2.

[0052] During the third pressure control cycle M30, neither the first ECU1 of the BWA module 100 nor the actuator motor AM works. Therefore, this ESP fluid supply mode M3 and this third pressure control cycle M30 can also be executed if the actuator motor AM of the BWA module 100 and / or the first ECU1 fails to control the actuator motor AM.

[0053] The above reference Figure 1 The first exemplary configuration describes three fluid supply modes that the vehicle braking system of this application can provide (when the vehicle is ignited or during normal driving) and pressure control cycles corresponding to each fluid supply mode. Specifically, it includes: a master cylinder fluid supply mode M1 in which the master cylinder TMC of the BWA module 100 supplies brake fluid to the wheel cylinders alone, wherein the first ECU of the BWA module 100 executes a first pressure control cycle M10 that controls the pressure on the master cylinder line C_MC1 / 2 by controlling the actuator motor AM (to ultimately regulate the output pressure of the brake fluid output from the wheel cylinder port of the ESP module 200); and a transitional fluid supply mode M2 ​​in which the master cylinder TMC and the reservoir RSV jointly supply brake fluid to the wheel cylinders, wherein the BWA... The first ECU1 of module 100 controls the actuator motor AM and the second ECU2 of ESP module 200 controls the pump motor PM to coordinate and jointly regulate the pressure of the fluid supply line of ESP module 200, thereby regulating the brake fluid pressure output from the wheel cylinder port of ESP module 200 (to the brake wheel cylinder); and the ESP fluid supply mode M3, in which brake fluid is supplied to the brake wheel cylinder solely by the accumulator RSV of BWA module 100, wherein the second ECU2 of ESP module 200 executes a third pressure control cycle M30 to control the pressure on the main section C_Pri1 / 2 of the fluid supply line of ESP module 200 by controlling the pump motor PM (to ultimately regulate the output pressure of the brake fluid output from the wheel cylinder port of ESP module 200). It should be understood that the above description of the fluid supply mode and pressure control cycle of the first exemplary configuration also applies to... Figure 2-4 The second to fourth exemplary configurations.

[0054] The present application's vehicle braking system features a transitional fluid supply mode M2, which is coordinated and executed by the first ECU of the BWA module 100 and the second ECU2 of the ESP module 200, between the master cylinder fluid supply mode M1 and the ESP fluid supply mode M3. This transitional fluid supply mode effectively solves the problems of large net boost amplitude and long response time that occur during the transition from the master cylinder fluid supply mode, which has a fast boost speed but low maximum boost pressure, to the ESP fluid supply mode, which has a high maximum boost pressure but a slow boost speed.

[0055] The following is for reference. Figure 8-15. The braking process of the vehicle braking method performed by the vehicle braking system of this application is described. In general, the braking process of this application first determines the brake fluid supply scheme ("supply scheme") to be executed based on the received braking request, and then actually executes the supply scheme. Specifically, when the required pressure P_req_br corresponding to the braking request is less than the preset warning pressure value P_alt_MC for the brake master cylinder TMC, the first fluid supply scheme STR1, which only includes the master cylinder fluid supply mode M1, is executed; when the required pressure P_req_br corresponding to the braking request is between the preset warning pressure value P_alt_MC and the limit pressure value P_lmt_MC of the brake master cylinder TMC, the second fluid supply scheme STR2 (M1+M2), which first uses the master cylinder fluid supply mode M1 and then the transition fluid supply mode M2, is executed; when the required pressure P_req_br corresponding to the braking request is greater than the limit pressure value P_lmt_MC of the brake master cylinder TMC, the third fluid supply scheme STR3 (M1+M2+M3), which first uses the master cylinder fluid supply mode M1, then the transition fluid supply mode M2, and finally the ESP fluid supply mode M3, is executed. In the second fluid supply scheme STR2, even when the master cylinder is sufficient to provide the required pressure P_req_br corresponding to the braking request, the ESP module 200's pump PE1 / 2 is still activated to supplement fluid supply to the main road section C_Pri1 / 2. The purpose is to be prepared to handle situations where the required pressure P_req_br exceeds the master cylinder TMC's limit pressure value P_lmt_MC (and therefore the master cylinder TMC itself can no longer meet the braking demand). This ensures that if such a situation occurs, the vehicle braking process can smoothly and promptly transition to the ESP fluid supply mode M3. Optionally, the warning pressure value P_alt_MC and the limit pressure value P_lmt_MC can be dynamically set to different values ​​based on the different adhesion coefficients of different road surfaces. These different adhesion coefficients can be obtained according to existing technologies. A detailed description is provided below with reference to the flowchart.

[0056] refer to Figure 8 The braking process of the vehicle braking system in any exemplary configuration of this application begins with the first step S1 upon receiving a braking request.

[0057] In the second step S2, the status information of whether the working status of the first ECU1 of the BWA module 100 and the actuator motor AM is normal, and the status information of whether the working status of the second ECU2 of the ESP module 200 and the pump motor PM is normal are obtained.

[0058] Following step S2, step S25, which determines whether the actuator motor AM of the BWA module 100 and the pump motor PM of the ESP module 200 are both in an abnormal operating state, is executed by the first ECU1 and the second ECU2. If both the actuator motor AM and the pump motor PM are in an abnormal operating state, the vehicle's braking system cannot provide braking function, and the braking function is implemented by the EPB module, which does not require the participation of the vehicle's braking system. Therefore, step S10, the process ends. Otherwise, the braking process proceeds to step S3.

[0059] In the third step S3, based on the status information of whether the first ECU1, actuator motor AM, second ECU2, and pump motor PM are operating normally, an appropriate fluid supply scheme (STR1, STR2, or STR3) is selected to supply brake fluid to the fluid supply line of the ESP module 200 and the pressure of the fluid supply line is adjusted accordingly to regulate the pressure of the brake fluid output at the wheel cylinder port. This third step S3 includes several cases: the first case S31, where the first ECU1, actuator motor AM, second ECU2, and pump motor PM are all in normal condition; the second case S32, where the first ECU1 and actuator motor AM are in normal condition, but the pump motor PM itself and / or the control of the pump motor PM by the second ECU2 are in an abnormal (or abnormal) operating state; and the third case S33, where the second ECU2 and pump motor PM are in normal condition, but the actuator motor AM itself and / or the control of the actuator motor AM by the first ECU1 are in an abnormal state.

[0060] Next, the braking process executes the fourth step, S4. In the fourth step, S4, brake fluid from the ESP module 200's supply line in the third step, S3, is supplied to the brake wheel cylinder to establish braking pressure within it. Optionally, if the second ECU2 is operating normally, the fourth step, S4, also includes a wheel cylinder pressure-holding operation that de-energizes the inlet valve at the wheel cylinder port to maintain brake fluid pressure in the wheel cylinder, and a wheel cylinder depressurization operation that de-energizes the inlet valve at the wheel cylinder port and energizes the outlet valve to release brake fluid from the wheel cylinder and return the released brake fluid to the accumulator via the drain line, thereby completing the braking cycle.

[0061] This process may also include an optional fifth step, S5: determining whether the vehicle is still in the ignition state. If the vehicle is still in the ignition state, return to step S2; otherwise, execute the end step S10.

[0062] Figure 9 The steps of the first case S31 are illustrated. In this case, the first ECU1 and actuator motor AM of the BWA module 100, as well as the second ECU2 and pump motor PM of the ESP module 200, are all operating normally.

[0063] In the first sub-step S312 of the first case S31, the first ECU1 or the second ECU1 calculates the required pressure P_req_br (i.e., the brake fluid pressure at the main segment C_Pri1 / 2 of the fluid supply line of the ESP module 200 or at the wheel cylinder port) and the corresponding vehicle required deceleration a_req_veh (a non-negative value) based on the received braking request. The required pressure P_req_br can be calculated based on one or more of the following using algorithms known in the art: pedal travel measured by the pedal travel sensor PTS, pedal force measured by the pedal force sensor PFT, real-time master cylinder pressure measured by the master cylinder sensor PS_MC, and real-time deceleration value measured by the deceleration sensor aS. Details are omitted here.

[0064] In the second sub-step S314, it is determined whether the required pressure P_br is less than the warning pressure value P_alt_MC of the brake master cylinder.

[0065] If the required pressure P_req_br is less than the warning pressure value P_alt_MC, it means that the brake master cylinder is sufficient to provide the required pressure P_req_br corresponding to the braking request. In this application, the first fluid supply scheme STR1, which only includes the master cylinder fluid supply mode M1, will be adopted. The third sub-step S316 of the braking process execution assignment is as follows: the required pressure P_req_br is assigned to the parameter master cylinder target pressure P_tgt_MC (the pressure that the brake master cylinder ultimately needs to provide) and the parameter pump target pressure P_tgt_PE is set to 0 (that is, the pump PE1 / 2 of the ESP module 200 does not need to work).

[0066] Then, the braking process proceeds to the fourth sub-step S318, where brake fluid is supplied to the ESP module 200's fluid supply line via the master cylinder, and the pressure at the wheel cylinder port of the ESP module 200's fluid supply line is controlled (or regulated) by controlling the pressure on the master cylinder line using the first pressure control cycle M10. Specifically, refer to the appendix... Figure 10aThe fourth sub-step S318 may include: a first sub-step S3182 measuring the real-time master cylinder pressure P_act_MC on the master cylinder line C_MC1 / 2 using the master cylinder sensor PS_MC, and a second sub-step S3184 selectively executing the specific operation of the first pressure control cycle M10 based on the real-time master cylinder pressure P_act_MC and the master cylinder target pressure P_tgt_MC (assigned in the third sub-step S316). Specifically, the second sub-step S3184 includes: a pressure boosting operation M10.2 when the difference (in absolute value form) between the real-time pressure P_act_MC and the target pressure P_tgt_MC of the master cylinder is outside a preset range and P_act_MC is less than P_tgt_MC, whereby the first ECU1 controls the actuator motor AM to rotate forward, thereby driving the piston of the brake master cylinder to move forward to increase the pressure in the master cylinder line C_MC1 / 2; a pressure holding operation M10.1 when the difference is within the preset range, whereby the first ECU1 controls the actuator motor AM to stop rotating to maintain the pressure in the master cylinder line C_MC1 / 2; and a pressure reduction operation M10.3 when the difference is outside the preset range and P_act_MC is greater than P_tgt_MC, whereby the first ECU1 controls the actuator motor AM to rotate in the reverse direction, thereby controlling the piston of the brake master cylinder to retract to reduce the pressure in the master cylinder line C_MC1 / 2.

[0067] Conversely, if it is determined in the second sub-step S314 that the required pressure P_req_br is not less than the warning pressure value P_alt_MC of the brake master cylinder TMC, this braking process proceeds to the fifth sub-step S311: determining whether the required pressure P_req_br is less than the limit pressure value P_lmt_MC of the brake master cylinder.

[0068] If so, it indicates that the master cylinder is still sufficient to provide the required pressure P_req_br corresponding to the braking request. However, this application will adopt a second fluid supply scheme STR2(M1+M2) consisting of master cylinder fluid supply mode M1 first and then transition fluid supply mode M2. The braking process enters the sixth sub-step S313 of the assignment: the required pressure P_req_br is assigned to both the parameter master cylinder target pressure P_tgt_MC (the pressure finally provided by the master cylinder) and the parameter pump target pressure P_tgt_PE. This means that in addition to the master cylinder TMC of BWA module 100 supplying fluid to the main road segment C_Pri1 / 2, the pump PE1 / 2 of ESP module 200 will also be activated to supplement the fluid supply to the main road segment C_Pri1 / 2.

[0069] Then, the braking process proceeds to the seventh sub-step S315 of the second fluid supply scheme STR2, which begins actual execution. (Refer to Appendix) Figure 10b This sub-step S315 may include:

[0070] The first sub-step S3152 is to measure the real-time pressure P_act_MC of the master cylinder on the master cylinder line C_MC1 / 2 using the master cylinder sensor PS_MC; the second sub-step S3154 is to determine whether the real-time pressure P_act_MC of the master cylinder is less than the warning pressure value P_alt_MC of the brake master cylinder TMC.

[0071] When the real-time pressure P_act_MC of the master cylinder is still less than the warning pressure value P_alt_MC, execute the third sub-step 3156 of the first pressure control cycle M10, which is executed by the first ECU1 to regulate the pressure in the master cylinder circuit C_MC1 / 2 (the specific operation is the same as the second sub-step S3184 mentioned above); and

[0072] When the real-time master cylinder pressure P_act_MC is not less than the warning pressure value P_alt_MC, the transitional fluid supply mode M2 ​​is executed, and the fourth sub-step S3158 is performed whereby the first ECU1 and the second ECU2 control the pressure in the master cylinder circuit C_MC1 / 2 and the main circuit C_Pri1 / 2 respectively using the second pressure control cycle M20. This sub-step is based on the real-time master cylinder pressure P_act_MC and the target master cylinder pressure P_tgt_MC and / or based on the real-time pump pressure P_act_PE and the target pump pressure P_tgt_PE (only applicable to...). Figure 1 First exemplary configuration and Figure 3 The third exemplary configuration) is executed.

[0073] Specifically, the fourth sub-step S3158 includes: performing a pressure boosting operation M20.2 when the difference (absolute value form) between the real-time pressure P_act_MC and the target pressure P_tgt_MC of the master cylinder is outside a preset range and P_act_MC is less than P_tgt_MC, wherein the first ECU1 controls the actuator motor AM to rotate forward or stop rotating, thus the actuator AT drives the piston of the brake master cylinder to move forward or stop to increase or maintain the pressure in the master cylinder line C_MC1 / 2, while the second ECU2 controls the pump motor PM to rotate, thereby driving the pump PE1 / 2 to draw brake fluid from the reservoir RSV, pressurize it, and replenish it to the main section C_Pri1 / 2 of the fluid supply line to increase the pressure in the main section C_Pri1 / 2; when the difference is within the preset range, performing a pressure holding operation M20.1, wherein the first ECU1 controls the pump motor AM to rotate forward or stop rotating, thus the first ECU1 controls the pump motor AM to rotate forward or stop rotating, thus the first ECU1 drives the pump motor AM to rotate forward or stop rotating, thus the first ECU2 drives the pump motor AM to rotate forward or stop rotating, thus the first ECU2 drives the pump motor AM to rotate forward or stop rotating, thus the first ECU2 drives the pump motor AM to rotate forward or stop rotating, thus the first ECU2 drives the pump motor AM to rotate forward or stop rotating, thus the second ... The actuator motor AM rotates in the opposite direction by a certain angle, thus the actuator AM controls the piston of the brake master cylinder to retract a certain distance to reduce a certain pressure in the master cylinder line C_MC1 / 2. At the same time, the second ECU2 controls the pump motor PM to rotate, thereby driving the pump PE1 / 2 to compensate for the pressure loss in the main section C_Pri1 / 2 (due to the pressure reduction in the master cylinder line C_MC1 / 2). When the difference is outside the preset range and P_act_MC is greater than P_tgt_MC, a pressure reduction operation M20.3 is performed, wherein the second ECU2 controls the pump motor PM to keep or stop rotating, thereby the pump PE1 / 2 to work or not work, while the first ECU1 controls the actuator motor AM to rotate in the opposite direction, thus the actuator AM controls the piston of the brake master cylinder to retract to reduce the pressure in the master cylinder line C_MC1 / 2 and the main section C_Pri1 / 2.

[0074] Conversely, if it is determined in the fifth sub-step S311 that the required pressure P_req_br is not less than the limit pressure value P_lmt_MC of the brake master cylinder TMC, it indicates that the brake master cylinder TMC is insufficient to provide the required pressure P_req_br corresponding to the braking request. In this case, this application adopts the third fluid supply scheme STR3(M1+M2+M3). At this time, the braking process enters the eighth (assignment) sub-step S317 and the actual execution sub-step S319. In step S317: the ultimate pressure P_lmt_MC is assigned to the master cylinder target pressure P_tgt_MC (the pressure ultimately provided by the brake master cylinder), and the required pressure P_req_br is assigned to the pump target pressure P_tgt_PE. This means that firstly, the master cylinder TMC of the BWA module 100 provides brake fluid to the main road section C_Pri1 / 2 until the ultimate pressure P_lmt_MC. Then, the pump PE1 / 2 of the ESP module 200 provides additional pressure to the main road section C_Pri1 / 2, which is approximately the difference between P_req_br and P_lmt_MC.

[0075] The details of the actual execution of step S319 differ slightly for the vehicle braking systems of the first and third exemplary configurations including the pump sensor PS_PE and the second and fourth exemplary configurations excluding the pump sensor PS_PE. (Refer to...) Figure 10c .

[0076] The actual execution of step S319 may include:

[0077] The first sub-step S3191 is to measure the real-time pressure P_act_MC of the master cylinder on the master cylinder line C_MC1 / 2 using the master cylinder sensor PS_MC.

[0078] The second sub-step S3192 is to determine whether the real-time pressure P_act_MC of the master cylinder is less than the warning pressure value P_alt_MC of the brake master cylinder TMC.

[0079] When the real-time pressure P_act_MC of the master cylinder is less than the warning pressure value P_alt_MC, the third sub-step 3193 is executed, and the pressure in the master cylinder circuit C_MC1 / 2 is adjusted by the first ECU1 using the first pressure control cycle M10 (the specific operation is the same as the second sub-step S3184 above).

[0080] The fourth sub-step S3194 further determines whether the real-time pressure P_act_MC of the master cylinder is less than the limit pressure value P_lmt_MC of the brake master cylinder TMC.

[0081] When the real-time pressure P_act_MC of the master cylinder is between the warning pressure value P_alt_MC and the limit pressure value P_lmt_MC, the fifth sub-step S3195 will be executed: In the transitional fluid supply mode M2, brake fluid is supplied to the fluid supply line of the ESP module 200 by the brake master cylinder TMC and pump PE1 / 2. The first ECU1 and the second ECU2 control the pressure in the master cylinder line C_MC1 / 2 and the main section C_Pri1 / 2 using the second pressure control cycle M20. The specific operation is the same as the fourth sub-step S3158 described above; and

[0082] When the real-time pressure of the master cylinder P_act_MC is not less than the limit pressure value P_lmt_MC, execute the sixth sub-step S3196: adopt the ESP fluid supply mode M3 to supply brake fluid to the fluid supply line of the ESP module 200 by the pump PE1 / 2 of the ESP module 200, and control the pressure in the main road section C_Pri1 / 2 by the second ECU2 with the third pressure control cycle M30.

[0083] For a vehicle braking system including a pump sensor PS_PE, the sixth sub-step S3196 may include: a first operation of measuring the real-time pump pressure P_act_PE on the main section C_Pri1 / 2 of the fluid supply line using the pump sensor PS_PE; and a second operation, wherein one of the boosting operation M30.2, the holding operation M30.1, and the depressurization operation M30.3 in the third pressure control cycle M30 is selectively executed based on the real-time pump pressure P_act_PE. Specifically, in the second operation: the boosting operation M30.2 is executed when the difference (in absolute value form) between the real-time pump pressure P_act_PE measured by the pump sensor PS_PE and the target pump pressure P_tgt_PE is outside a preset range and P_act_PE is less than P_tgt_PE. Figure 6 The second ECU2 controls the pressure valve SC1 / 2 to open and close, and controls the pump motor PM to rotate, thereby driving the pump PE1 / 2 to draw brake fluid from the reservoir RSV, pressurize it, and replenish it to the main section C_Pri1 / 2 of the fluid supply line to increase the pressure in the main section C_Pri1 / 2; when the difference is within the preset range, the pressure holding operation M30.1 is performed. Figure 6 Or 7), the second ECU2 controls the system pressure valve SC1 / 2 to have a certain opening degree or to be energized and disconnected via pulse width modulation, and controls the pump motor PM to rotate or stop rotating, thereby driving or stopping the pump PE1 / 2 to compensate for the pressure loss in the main road section C_Pri1 / 2 (due to the certain opening of the system pressure valve SC1 / 2) or to maintain the pressure in the main road section C_Pri1 / 2; and performs pressure reduction operation M30.3 when the difference is outside the preset range and P_act_PE is greater than P_tgt_PE. Figure 7 In this system, the second ECU2 controls the system pressure valve SC1 / 2 to a certain opening degree through pulse width modulation and controls the pump motor PM to rotate or stop rotating, thereby driving or stopping the pump PE1 / 2 to reduce the pressure in the main road section C_Pri1 / 2.

[0084] For a vehicle braking system that does not include the pump sensor PS_PE, the sixth sub-step S3196 may include: a first operation of measuring the real-time vehicle deceleration a_act_veh using the deceleration sensor aS; and a second operation, wherein one of the boost operation M30.2, the pressure holding operation M30.1, and the depressurization operation M30.3 in the third pressure control cycle M30 is selectively executed based on the real-time vehicle deceleration a_act_veh. Specifically, in the second operation: the boost operation M30.2 is executed when the difference (in absolute value form) between the real-time vehicle deceleration a_act_veh and the target vehicle deceleration a_tgt_veh calculated based on braking demand is outside a preset range and a_act_veh is less than a_tgt_veh. Figure 6Same as above; when the difference is within the preset range, perform pressure holding operation M30.1. Figure 6 Or 7), same as above; and when the difference is outside the preset range and a_act_veh is greater than a_tgt_veh, perform decompression operation M30.3 ( Figure 7 ), same as above.

[0085] Optionally, for a vehicle braking system excluding the pump sensor PS_PE, the second sub-step S3192 and the fourth sub-step S3194 can be modified as follows: determining whether the real-time vehicle deceleration a_act_veh is less than the vehicle warning deceleration value a_alt_veh (a preset non-negative value) corresponding to the warning pressure value P_alt_MC of the master cylinder TMC, and determining whether the real-time vehicle deceleration a_act_veh is less than the vehicle limit deceleration value a_1mt_veh (a preset non-negative value) corresponding to the limit pressure value P_lmt_MC of the master cylinder TMC. Everything else remains unchanged.

[0086] Figure 11 The steps of the second scenario S32 are shown. In this case, the first ECU1 and actuator motor AM are in normal operation, while the pump motor PM itself is in an abnormal operation or the second ECU2's control of the pump motor PM is malfunctioning. Under these circumstances, only the master cylinder fluid supply mode M1 can supply fluid to the ESP module's fluid supply line, which in turn supplies fluid to the brake wheel cylinders. Furthermore, only the first ECU1 can execute the first pressure control operation M10 to ultimately adjust the brake fluid output pressure at the wheel cylinder port of the ESP module 200's fluid supply line.

[0087] In the first sub-step S322, the first ECU1 of the BWA module 100 (or the second ECU2 when the ESP module 200 is functioning normally) calculates the required pressure P_req_br that the brake wheel cylinder needs to provide based on the received braking request. This step is the same as... Figure 9 The first step, S312.

[0088] In the second sub-step S324, the maximum locking pressure of each brake wheel cylinder WC1 / 2 / 3 / 4 on different road surfaces is calculated using methods known in the art, and the smallest one is assigned as the parameter wheel cylinder minimum locking pressure P_lock_min_WC.

[0089] In the third sub-step S326, the smaller of the required pressure P_tgt_br obtained in the first sub-step S322 and the minimum wheel cylinder lock-up pressure P_lock_min_WC obtained in the second step S324 is assigned to the parameter master cylinder target pressure P_tgt_MC.

[0090] Next, in the fourth sub-step S328, the first ECU1 controls the pressure in the master cylinder circuit C_MC1 / 2 using the first pressure control operation M10, and supplies brake fluid to the brake fluid supply circuit of the ESP module 200 in master cylinder fluid supply mode M1. This step is the same as... Figure 9 The fourth sub-step S318 will not be described in detail here.

[0091] In the third scenario, S33, the second ECU2 and pump motor PM are in normal operation, but the actuator motor AM itself is in an abnormal operation or the first ECU1's control of the actuator motor AM is malfunctioning. In this case, ESP fluid supply mode M3 and third pressure control operation M30 are executed. For vehicle braking systems including pump sensor PS_PE, refer to... Figure 12a In this case, the following sub-steps are executed sequentially: the first sub-step S332a (which is the same as the above) calculates the required pressure P_req_br that the brake wheel cylinder needs to provide based on the braking request. Figure 9 Step S312 is the same as above; the second sub-step S334a assigns the smaller of the required pressure P_req_br and the preset maximum pressure value P_max_PE that the pump PE1 / 2 can provide to the parameter pump target pressure P_tgt_PE; and the third sub-step S336a (same as above) executes the ESP liquid supply mode M3 and the third pressure control cycle M30. Figure 10c (Sub-step S3196). For vehicle braking systems that do not include the pump sensor PS_PE, refer to... Figure 12b In this case, the following sub-steps are executed sequentially: the first sub-step S332b calculates the vehicle's required deceleration a_req_veh based on the braking request; the second sub-step S334b assigns the smaller of the vehicle's required deceleration a_req_veh and the maximum deceleration a_max_PE corresponding to the maximum pressure value P_max_PE that the preset pump PE1 / 2 can provide to the vehicle's target deceleration a_tgt_veh; and the third sub-step S3366 executes the ESP fluid supply mode M3 and the third pressure control operation M30 (same as above). Figure 10c Sub-step S3196).

[0092] The above description, with reference to the accompanying drawings, details several situations or modes for supplying brake fluid to the ESP module 200 and for controlling or adjusting the brake fluid pressure supplied to the ESP module 200. When a braking request is received and vehicle braking is performed during normal vehicle operation, the vehicle braking system provides a transitional supply mode M2 ​​between the master cylinder supply mode M1 and the ESP supply mode M3. This overcomes the disadvantages of large net pressure increase and long response time that occur during the transition from the master cylinder supply mode with a fast boost speed but low maximum boost pressure to the ESP supply mode with a high maximum boost pressure but slow boost speed. This application also provides detailed steps for selecting these modes, namely, comparing the real-time pressure of the master cylinder measured by the master cylinder sensor with preset warning pressure and limit pressure values ​​for the brake master cylinder, and comparing the real-time pump pressure or real-time deceleration measured by the pump sensor or deceleration sensor with preset limit pressure values ​​for the brake master cylinder or the vehicle limit deceleration corresponding to those limit pressure values. In particular, this application provides a control method for adjusting the supply pressure of the ESP module using a second pressure control cycle in the transitional supply mode.

[0093] The principles of this application have been described in detail above with reference to the exemplary configurations shown in the accompanying drawings. The drawings and the foregoing description are for illustrative purposes only and do not constitute a limitation on this application. Those skilled in the art, after understanding the essence and principles of this application, can make any modifications, additions, deletions, or substitutions to the structural details, and the resulting new embodiments all fall within the protection scope of this application.

Claims

1. A vehicle braking system, comprising: A pedal sensor for a vehicle's brake pedal (BP), the pedal sensor including a pedal force sensor and / or a pedal travel sensor; BWA module (100) includes: an actuator motor (AM), an actuator (AT) driven by the actuator motor, a brake master cylinder (MC, TMC) driven by the actuator, a accumulator (RSV) connected to the brake master cylinder, a master cylinder port (Pt_MC1 / 2) connected to the brake master cylinder, a accumulator port (Pt_RSV1 / 2) connected to the accumulator, a master cylinder sensor (PS_MC) for measuring the real-time pressure (P_act_MC) of the master cylinder of the brake master cylinder (MC), and a first control unit (ECU1) communicatively connected to the pedal sensor and used to control the actuator motor of BWA module (100); ESP module (200) includes: wheel cylinder ports (Pt_WC1 / 2 / 3 / 4) configured for connection to the brake wheel cylinders of a vehicle; an inlet port (Pt_SC1 / 2) communicating with the master cylinder port; an outlet port (Pt_PE1 / 2) communicating with the accumulator port; a fluid supply line (C_SC1 / 2+C_Pri1 / 2) connecting the inlet valve of the wheel cylinder port and the inlet port and equipped with a system pressure valve (SC1 / 2); and an outlet valve connecting the wheel cylinder port. The system includes a drain line (C_PE1 / 2) connecting the drain port, a main section (C_Pri1 / 2) of the supply line located between the system pressure valve and the inlet valve connected to the drain line, a replenishment line for a pump (PE1 / 2) that allows brake fluid to flow only from the drain line to the main section, a pump motor (PM) driving the pump, and a second control unit (ECU2) that communicates with both the pedal sensor and the first control unit and is used to control the pump motor of the ESP module (200).

2. The vehicle brake system of claim 1, wherein, The first control unit and the second control unit are configured to: in the first case where both the actuator motor of the BWA module and the pump motor of the ESP module are working normally, when the real-time pressure of the master cylinder is between a preset warning pressure value and a limit pressure value, execute a transitional fluid supply mode (M2) that simultaneously supplies brake fluid from the master cylinder and brake fluid from the reservoir to the main road section; and execute an ESP fluid supply mode (M3) that supplies only brake fluid from the reservoir to the main road section when the real-time pressure of the master cylinder is greater than the limit pressure value.

3. The vehicle brake system of claim 2, wherein, In the transitional fluid supply mode (M2), the required pressure calculated based on the braking request is greater than the warning pressure value.

4. The vehicle braking method according to claim 3, wherein, The first control unit and the second control unit are configured to execute the ESP liquid supply mode (M3) in a second situation where the actuator motor cannot work properly, but the pump motor of the ESP module works properly.

5. The vehicle braking system according to claim 4, wherein, The first control unit and the second control unit are configured to: in the transitional liquid supply mode (M2), perform a second pressure control cycle (M20) by coordinating the actuator motor and pump motor to perform pressurization, pressure holding, and pressure reduction operations on the main flow path; and / or The second control unit is configured to perform a third pressure control cycle (M30) in the ESP supply mode (M3) by controlling the system pressure valve and pump motor, including pressurization operation, pressure holding operation and pressure reduction operation, which includes increasing, maintaining and decreasing the pressure on the main road section.

6. The vehicle braking system according to claim 5, wherein, When pump sensors are installed on the main road sections, the pressurization, pressure holding, and pressure reduction operations of the third pressure control cycle are selected based on the real-time pump pressure measured by the pump sensors; or In the case where no pump sensor is installed on the main road section, but the first control unit or the second control unit includes a deceleration sensor, the pressurization operation, pressure holding operation and depressurization operation of the third pressure control cycle are selected based on the real-time deceleration measured by the deceleration sensor.

7. The vehicle braking system according to any one of claims 1-6, wherein: The brake master cylinder includes two master cylinder chambers, and the BWA module (100) and the ESP module (200) each include two master cylinder ports and two fluid inlet ports that are connected to each other; or the brake master cylinder includes one master cylinder chamber, and the BWA module (100) and the ESP module (200) each include one master cylinder port and one fluid inlet port that are connected to each other; and / or The ESP module (200) may or may not include a pump sensor (PS_PE) installed on the main road section for measuring the real-time pump pressure of the pump.

8. A vehicle braking method performed using a vehicle braking system according to any one of claims 1-7, comprising: The first step in obtaining a braking request; The second step is to obtain information on whether the actuator motor of the BWA module is working properly and whether the pump motor (PM) of the ESP module is working properly. The third step involves selecting an appropriate fluid supply scheme to supply brake fluid to the main section of the ESP module's fluid supply line, based on the information obtained in the second step, provided that at least one of the actuator motor of the BWA module and the pump motor (PM) of the ESP module is functioning normally. The fourth step involves supplying brake fluid from the ESP module's supply line in the third step to the brake wheel cylinder to increase the brake fluid pressure in the brake wheel cylinder. The fourth step includes: if the solenoid valves of the ESP module are functioning normally, performing a wheel cylinder decompression operation to discharge the brake fluid from the brake wheel cylinder to the accumulator of the BWA module via the ESP module's drain line.

9. The vehicle braking method of claim 8, wherein, In the third step, in the first case where the information in the second step shows that both the actuator motor of the BWA module and the pump motor of the ESP module are working normally, when the real-time pressure of the master cylinder is between the warning pressure value and the limit pressure value, a transitional fluid supply mode (M2) is executed, which simultaneously supplies brake fluid from the master cylinder and brake fluid from the reservoir to the main road section. And when the real-time pressure of the master cylinder is greater than the limit pressure value, an ESP fluid supply mode (M3) is executed, which supplies only brake fluid from the reservoir to the main road section.

10. The vehicle braking method of claim 9, wherein, In the third step, the ESP liquid supply mode (M3) is executed in the second case where the information in the second step shows that the actuator motor is not working properly, but the pump motor of the ESP module is working properly.

11. The vehicle braking system according to claim 10, wherein, In the transitional liquid supply mode (M2), the first control unit and the second control unit respectively control the actuator motor and the pump motor in a coordinated manner to perform a second pressure control cycle (M20) including pressurization, pressure holding, and pressure reduction operations on the main road section (C_Pri1 / 2); and / or In the ESP fluid supply mode (M3), the second control unit performs a third pressure control cycle (M30) by controlling the system pressure valve and pump motor, which includes pressurization, pressure holding and pressure reduction operations on the main road section (C_Pri1 / 2).

12. The vehicle braking system according to claim 11, wherein, When pump sensors are installed on the main road sections, the pressurization, pressure holding, and pressure reduction operations of the third pressure control cycle are selected based on the real-time pump pressure measured by the pump sensors; or In the case where no pump sensor is installed on the main road section, but the first control unit or the second control unit includes a deceleration sensor, the pressurization operation, pressure holding operation and depressurization operation of the third pressure control cycle are selected based on the real-time deceleration measured by the deceleration sensor.

13. The vehicle braking method according to claim 12, wherein, When a pump sensor is installed on the main road section (C_Pri1 / 2), the pressurization operation of the third pressure control cycle (M30) is performed when the first difference between the real-time pump pressure measured by the pump sensor and the target pump pressure is outside a first preset range and the former is less than the latter; the pressure holding operation is performed when the first difference is within the first preset range; and the pressure reduction operation is performed when the first difference is outside the first preset range and the former is greater than the latter, or In the case where the vehicle braking system does not include the pump sensor, but the first control unit or the second control unit includes a deceleration sensor, the boost operation of the third pressure control operation (M30) is performed when the second difference between the real-time deceleration measured by the deceleration sensor and the vehicle target deceleration calculated based on the braking request is outside a second preset range and the former is less than the latter. The pressure holding operation is performed when the second difference is within the second preset range; The decompression operation is performed when the second difference is outside the second preset range and the former is greater than the latter.

14. A BWA module (100) for a vehicle braking system according to any one of claims 1-7, comprising a module housing and disposed on the module housing: one or two master cylinder ports (Pt_MC1 / 2) communicating with one or two master cylinder chambers of the brake master cylinder, and one or two accumulator ports (Pt_RSV1 / 2) communicating with one or two accumulator spaces of the accumulator. wherein The actuator motor (AM), the actuator (AT), the brake master cylinder (MC, TMC), and the reservoir (RSV) are all housed within the module housing.

15. An ESP module (200) for a vehicle braking system according to any one of claims 1-7, comprising a module housing and disposed on the module housing: four wheel cylinder ports (Pt_WC1 / 2 / 3 / 4), one or two drain ports (Pt_PE1 / 2), and one or two inlet ports (Pt_SC1 / 2). wherein, The system pressure valve (SC1 / 2), the liquid supply line (C_SC1 / 2+C_Pri1 / 2), the liquid drain line (C_PE1 / 2), the liquid replenishment line, the pump (PE1 / 2), and the pump motor (PM) are all located inside the module housing.

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