Electro-hydraulic brake system

Abstract

The present disclosure provides an electro-hydraulic brake system capable of appropriately providing a redundant brake force, i.e., an electro-hydraulic brake system of a so-called redundancy function, in a situation where a driver does not drive or pays less attention to driving, such as autonomous driving or intelligent cruise control, and a main brake device fails.

Description

Technical Field

[0001] This disclosure relates to an electro-hydraulic braking device, and more specifically, to an electro-hydraulic braking device capable of performing redundant braking. Background Technology

[0002] The description in this section provides background information on the implementation methods only and does not constitute related technology.

[0003] Typically, an electro-hydraulic braking system uses a hydraulic modulator to adjust the braking pressure of each wheel after sensing the driver's pedal pressure through sensors.

[0004] Electro-hydraulic braking systems include sensors and a pedal simulator. The sensors sense the pedal stroke distance to determine the driver's desired braking pressure, while the pedal simulator allows the driver to feel the pedal pressure, for example, that found in a typical hydraulic braking system.

[0005] The control unit determines the braking force required by the driver through pedal stroke sensors, pressure sensors, etc., and generates braking force at the wheel brakes by driving specific wheel braking units.

[0006] A wheel braking unit typically includes a main master cylinder structure for generating hydraulic pressure, and hydraulic circuits and valves for transmitting the hydraulic pressure generated by the main master cylinder to the braking devices mounted on the wheels of the vehicle.

[0007] Figure 8 This is a block diagram illustrating an example of an electro-hydraulic braking system of the relevant technology.

[0008] Figure 8 The electro-hydraulic braking system shown in the related technology is configured to not only perform the basic function of providing the driver with a reaction feel while sensing the degree of pedal force applied by the driver by means of a pedal simulator, but also perform the function of providing a backup master cylinder for redundant braking force in the event of a failure of the main braking device.

[0009] In other words, the hydraulic circuit and valves are configured so that the brakes can be driven by the driver's pedal force even if the main master cylinder driven by the motor is not working in reverse mode, which is a situation where power is not supplied to the braking system or there is a problem with the function of the electric actuator, electronic control valve, etc.

[0010] However, the electro-hydraulic braking systems of this technology are configured to provide physical braking force by a human, even when driving in reverse mode, under the assumption that the driver is essentially paying attention to surrounding objects. That is, according to the electro-hydraulic braking systems of this technology, for example, when the vehicle is driving in intelligent cruise control mode or autonomous mode, the driver may not be able to react quickly to a malfunction of the braking system and may miss the opportunity to physically operate the pedal, potentially leading to a serious accident.

[0011] Furthermore, because the electro-hydraulic braking system of the relevant technology is not equipped with a pressure booster such as a pressure booster on the spare master cylinder, there is a difficulty that even if the driver presses the brake pedal at the appropriate time, it is impossible to generate braking pressure and its tendency to increase is suitable for emergency braking. Summary of the Invention

[0012] According to at least one aspect, this disclosure provides an electronic brake comprising: a plurality of wheel braking units that provide braking force to the wheels of a vehicle; a main braking device configured to generate brake fluid pressure in cooperation with a main brake motor; a secondary braking device configured to generate brake fluid pressure in cooperation with a secondary brake motor; a hydraulic circuit valve device configured to selectively transmit the brake fluid pressure generated by the main braking device or the secondary braking device to the plurality of wheel braking units; a main controller configured to control the main brake motor of the main braking device according to a brake input; and an auxiliary controller configured to control the secondary brake motor of the secondary braking device according to a brake input, and configured to control the hydraulic circuit valve device to transmit the brake fluid pressure generated by the secondary braking device to only some of the plurality of wheel braking units in the event of a failure of the main controller or the main braking device. Attached Figure Description

[0013] Figure 1 This is a block diagram schematically illustrating the structure of an electro-hydraulic braking system according to an embodiment of the present disclosure.

[0014] Figure 2 This is a schematic hydraulic circuit diagram illustrating the structure of an electro-hydraulic braking system according to an embodiment of the present disclosure.

[0015] Figure 3 This is a diagram showing the hydraulic conditions generated in the brake backup system during startup.

[0016] Figure 4 This is a diagram showing the hydraulic state during normal braking operation.

[0017] Figure 5 This is a diagram showing the hydraulic conditions during normal braking and stopping operations.

[0018] Figure 6 This is a diagram showing the hydraulic state during redundant braking operation.

[0019] Figure 7 This is a diagram showing the hydraulic state during redundant braking and stopping operations.

[0020] Figure 8 This is a block diagram illustrating an example of an electro-hydraulic braking system of the relevant technology. Detailed Implementation

[0021] Therefore, this disclosure provides an electro-hydraulic braking system that can appropriately provide redundant braking force when the driver is not driving or pays less attention to driving (such as autonomous driving or intelligent cruise control) and the main braking device fails, i.e., an electro-hydraulic braking system that provides so-called redundancy.

[0022] Furthermore, this disclosure provides an electro-hydraulic braking system that has a smaller, more space-saving size and is capable of performing the required redundant functions.

[0023] The purpose of this disclosure is not limited to the above-described purposes, and other purposes will be clearly understood by those skilled in the art from the following description.

[0024] In the following description, some exemplary embodiments of this disclosure will be described in detail with reference to the accompanying drawings. In the following description, although elements are shown in different drawings, the same reference numerals preferably denote the same elements. Furthermore, in the following description of some embodiments, for the purpose of clarity and brevity, detailed descriptions of known functions and constructions incorporated therein will be omitted.

[0025] Furthermore, terms such as first, second, A, B, (a), (b), etc., are used only to distinguish one component from another and do not imply or suggest the substance, order, or sequence of the components. Throughout the specification, when a component “comprises” or “includes” a component, that component means that it also includes other components without excluding them, unless specifically stated to the contrary. Terms such as “unit”, “module,” etc., refer to one or more units for performing at least one function or operation, which can be implemented by hardware, software, or a combination thereof.

[0026] Figure 1 This is a block diagram schematically illustrating the structure of an electro-hydraulic braking system according to an embodiment of the present disclosure.

[0027] Figure 2 This is a schematic hydraulic circuit diagram illustrating the structure of an electro-hydraulic braking system according to an embodiment of the present disclosure.

[0028] Reference Figure 1 and Figure 2 According to an embodiment of the present disclosure, the electro-hydraulic braking system 1 includes a plurality of wheel braking units w1, w2, w3 and w4 that provide braking force to the wheels of a vehicle; a main braking device 14 configured to change the pressure of the brake fluid in cooperation with a main brake motor; a secondary braking device 15 configured to change the pressure of the brake fluid in cooperation with a secondary brake motor; a hydraulic circuit valve device 16 configured to selectively transmit hydraulic pressure of the brake fluid to the plurality of wheel braking units w1, w2, w3 and w4; a main controller 18 configured to control the main braking device's main brake motor according to a brake input PSS; and an auxiliary controller 17 configured to control the secondary braking device 15's secondary brake motor according to a brake input PSS.

[0029] In systems that use liquids, a reservoir is installed to replenish the liquid when the volume of the liquid is insufficient due to changes in temperature, and the reservoir is also called a liquid storage tank.

[0030] Brake fluid is stored in reservoir 10 for use in electro-hydraulic braking system 1.

[0031] The pedal, which rotates according to the user's operation, is connected to the pedal simulator 12.

[0032] The pedal simulator 12 is configured to provide a corresponding reaction force to the pedal as the pedal moves. This reaction force can be defined as the resistance or pedal force exerted on the driver when the brake pedal is depressed. In this disclosure, the pedal simulator 12 is not in fluid communication with the hydraulic circuit valve device 16 of the braking system. That is, the pedal simulator 12 is fluidly separated from the hydraulic circuit valve device. Furthermore, the pedal simulator 12 is also fluidly separated from the reservoir 10. In other words, in this disclosure, the pedal simulator 12 can be physically integrated with the main brake device 14 and the auxiliary brake device 15, but this disclosure is not limited to this embodiment and includes cases where the pedal simulator 12 is separately arranged from the main brake device 14 and the auxiliary brake device 15 to enable the transmission of brake signals.

[0033] According to this disclosure, the pedal simulator 12 is not limited to... Figure 1 The structure of the embodiment shown. Within the spirit of changing the pedal force and the pressure of the brake fluid within it, the structure and function of the pedal simulator 12 can be constructed in various types.

[0034] Furthermore, in the electro-hydraulic braking system according to this disclosure, the pedal simulator 12 can be omitted. That is, the braking signal can correspond to a braking signal or deceleration signal provided by an autonomous system, and the driver can be excluded from driving actions including braking. In this case, the electro-hydraulic braking system according to this disclosure can be a system in which the braking input PSS input to the main controller 18 and the auxiliary controller 17 is a signal generated by an autonomous controller for driving, i.e., a so-called brake-by-wire (BBW) system.

[0035] The hydraulic circuit valve device 16 is in fluid communication with the main braking device 14, the auxiliary braking device 15, and the multiple wheel braking units w1, w2, w3, and w4, and is configured to change the internal passages, i.e., the passages in which hydraulic pressure is applied or the passages in which oil flows between the reservoir 10, the main braking device 14, the auxiliary braking device 15, and the multiple wheel braking units w1, w2, w3, and w4, in response to the first valve control signals VCS1, VCS2, and the second valve control signals VCS2, VCS2.

[0036] Multiple wheel brake units w1, w2, w3, and w4 are configured to apply braking force to the wheels of a vehicle using hydraulic pressure. The multiple wheel brake units w1, w2, w3, and w4 may be, for example, caliper brakes. The multiple wheel brake units w1, w2, w3, and w4 can be selectively fluidly connected to one or more of the reservoir 10, the main brake unit 14, and the auxiliary brake unit 15 via a hydraulic circuit valve device 16. For example, hydraulic pressure generated at the main brake unit 14 or the auxiliary brake unit 15 can be applied to the multiple wheel brake units w1, w2, w3, and w4 via the hydraulic circuit valve device 16. In this case, the multiple wheel brake units w1, w2, w3, and w4 can apply braking force corresponding to the hydraulic pressure to the wheels of the vehicle. The multiple wheel brake units w1, w2, w3, and w4 can be fluidly connected to the reservoir 10 via the hydraulic circuit valve device 16. In this case, the hydraulic pressure of the multiple wheel brake units w1, w2, w3, and w4 can be atmospheric pressure or a pressure corresponding to atmospheric pressure, and the braking force can be removed.

[0037] The main braking device 14 is configured to change the pressure of the brake fluid inside according to the first motor control signal MCS1. The main braking device 14 has a hollow structure. The main braking device 14 includes a piston disposed in its internal space and two hydraulic chambers separated by the piston. The piston is configured to move to one side as the motor rotates, that is, to reciprocate between the hydraulic chambers.

[0038] When the main brake motor rotates clockwise or counterclockwise via the first motor control signal MCS1, the piston moves to one side or the other side and can press the brake fluid in the two hydraulic chambers individually.

[0039] The main braking device 14 can be selectively fluidly connected to one or more of the reservoir 10, the auxiliary braking device 15, and the multiple wheel braking units w1, w2, w3 and w4 via the hydraulic circuit valve device 16.

[0040] The auxiliary braking device 15 is configured to change the internal brake fluid pressure according to the second motor control signal MCS2. The auxiliary braking device 15 can be an oil pump structure and, for example, can be configured to pump brake fluid as the auxiliary brake motor rotates when the auxiliary brake motor is operated via the second motor control signal MCS2. The oil flow path through the auxiliary braking device 15 can be transmitted to multiple wheel braking units w1, w2, w3, and w4 via the hydraulic circuit valve device 16. Specifically, the hydraulic pressure generated at the auxiliary braking device 15 can be transmitted sequentially to the wheel passages via the second master brake valve 142 and the second traction control valve 162. Furthermore, referring to… Figures 2 to 7 According to an embodiment of the present disclosure, the auxiliary braking device 15 is disposed between a chamber formed in front of the piston of the main braking device 14 and the reservoir 10.

[0041] However, in embodiments of this disclosure, the auxiliary braking device 15 may be a pump with a small capacity or a small output compared to the main braking device 14. Therefore, the auxiliary braking device 15 may be configured to supply hydraulic pressure to only one, two, or three of the four wheel braking units. In the embodiment of this disclosure shown in the figures, the auxiliary braking device 15 is configured to transmit hydraulic pressure to only two wheel braking units w3 and w4 via the hydraulic circuit valve device 16.

[0042] The hydraulic circuit valve device 16 is in fluid communication with one or more of the reservoir, the main braking device 14 and the auxiliary braking device 15, and the multiple wheel braking units w1, w2, w3 and w4.

[0043] The hydraulic circuit valve device 16 is configured to change the internal oil flow path in response to the first valve control signal VCS1 of the main controller 18 and the second valve control signal VCS2 of the auxiliary controller. That is, the oil flow path through which the oil is transmitted between the reservoir, the main braking device 14, the auxiliary braking device 15, and the multiple wheel braking units w1, w2, w3 and w4.

[0044] In embodiments of this disclosure, the hydraulic circuit valve device 16 includes some or all of a plurality of main brake control valves 24 associated with the operation of the main brake device 14, a plurality of secondary brake control valves 25 associated with the operation of the secondary brake device 15, and a plurality of attitude control valves 26 associated with the attitude control of the vehicle.

[0045] The multiple main brake control valves 24 may include a first main brake control valve 141 that opens / closes the hydraulic path between the reservoir 10 and the main brake device 14 and the hydraulic path between the reservoir 10 and the attitude control valve 26, and a second main brake valve 142 that opens / closes the hydraulic path between the auxiliary brake device 15 and the main brake device 14 and the hydraulic path between the auxiliary brake device 15 and the attitude control valve 26.

[0046] The second master brake valve 142 is disposed between the front chamber of the master brake unit 14 and the reservoir. The second master brake valve 142 is configured to determine whether hydraulic pressure is transmitted from the auxiliary brake unit to the wheel brake unit based on the opening / closing of the second master brake valve. When the wheel brakes are pressed, the second master brake valve 142 closes, thereby preventing the working fluid in the front chamber from being transmitted to the reservoir 10.

[0047] Multiple auxiliary brake control valves 25 may include a first auxiliary brake valve 151 and a second auxiliary brake valve 152 that open / close the hydraulic path between the reservoir 10 and the second main brake valve 142.

[0048] The first auxiliary brake valve 151 and the second auxiliary brake valve 152 are arranged in parallel between the second main brake valve 142 and the reservoir 10. The first auxiliary brake valve 151 and the second auxiliary brake valve 152 are configured to regulate the hydraulic pressure at the wheel brake unit.

[0049] The first auxiliary brake valve 151 is open during normal operating time and is used to control the set pressure at some of the wheel brakes w3 and w4. Specifically, when braking pressure is transmitted to some of the wheel brakes w3 and w4, the amount of fluid required to generate the desired braking pressure is sent to the wheels, while other fluid is sent to the reservoir 10. Therefore, the desired braking pressure can be generated at the wheel brakes w3 and w4.

[0050] The second auxiliary brake valve 152 opens or closes during normal operation depending on whether current is applied, and is configured to open when the main brake unit malfunctions (e.g., ...). Figure 7 (as shown), and opens when the secondary braking device 15 reduces the pressure transmitted hydraulically to the wheels.

[0051] When the pressure at the wheel brake unit decreases, the second master brake valve 142 opens, thus transferring working fluid from the front chamber of the master brake unit 14 to the second master brake valve 142. Because the second master brake valve 142 is open, working fluid is transferred from the second master brake valve to the first auxiliary brake valve 151 and / or the second auxiliary brake valve 152. When the pressure of the wheel brake decreases, because the first auxiliary brake valve 151 and / or the second auxiliary brake valve 152 are open, working fluid is transferred to the reservoir. That is, working fluid is sequentially transferred to the front chamber, the second master brake valve 142, the first auxiliary brake valve 151, the second auxiliary brake valve 152, and the reservoir 10.

[0052] Multiple attitude control valves 26 are configured to regulate the hydraulic pressure applied to multiple wheel braking units w1, w2, w3, and w4 based on attitude control signals from controller 110. The attitude control valves 26 are configured to open / close the oil flow path between the main brake 14 and the multiple wheel braking units w1, w2, w3, and w4, or between the auxiliary brake 15 and the multiple wheel braking units w1, w2, w3, and w4, based on attitude control signals.

[0053] The attitude control valve 26 is configured to independently control the braking force of each of the multiple wheel braking units w1, w2, w3 and w4, and is configured to perform the functions of anti-lock braking system (ABS), traction control system (TCS) and electronic stability control (ECS).

[0054] The attitude control valve 26 includes four pairs of inlet valves and outlet valves, configured such that one inlet valve and one outlet valve are provided in each brake channel for directly supplying oil to each of the wheel braking units w1, w2, w3, and w4 or for discharging oil. Furthermore, the attitude control valve 26 includes a first traction control valve 161, a second traction control valve 162, and a mixing valve 163 for distributing hydraulic pressure generated from the main braking device 14 or the auxiliary braking device 15 to each brake channel.

[0055] Furthermore, in the event of a failure in the main braking device 14 or the main controller 18, the auxiliary braking motor of the auxiliary braking device 15 is operated according to the second motor control signal MCS2 from the auxiliary controller 17. The auxiliary braking device 15, operating in conjunction with the auxiliary braking motor, transmits pressurized brake fluid to the hydraulic circuit valve assembly 16. The brake fluid is transmitted to multiple wheel braking units w1, w2, w3, and w4, thus enabling effective redundant braking via electronic control in redundant braking situations.

[0056] In other words, according to this disclosure, even if the main braking device fails when the driver is not driving or paying less attention to driving (such as intelligent cruise control or autonomous driving), redundant braking force can still be provided appropriately.

[0057] Furthermore, considering the possibility of malfunction in the device performing the electronically controlled braking function, this disclosure also includes an additional device with similar functionality, thus enabling the possibility of preventing problems caused by such malfunctions and ensuring a so-called redundant braking system. In particular, according to this disclosure, in ensuring this redundancy, proper braking function can be achieved in the event of a failure of the main braking device by simply adding a pump and valve system without actually employing a separate additional braking system.

[0058] The main controller 18 controls the control valve of the hydraulic circuit valve assembly 16 and the motor that operates in cooperation with the main brake assembly 14, thereby generating a braking force corresponding to the degree of pedal rotation and a braking input PSS provided by the autonomous device. The main controller 18 can generate a first motor control signal and transmit it to the main brake motor, which controls the main control motor that operates in cooperation with the main brake assembly 14. The hydraulic pressure generated by the main brake assembly 14 is transmitted through the hydraulic circuit valve assembly 16 to multiple wheel brake units w1, w2, w3, and w4. In this case, the main controller 18 establishes an oil flow path between the main brake assembly 14 and the multiple wheel brake units w1, w2, w3, and w4 by transmitting a first adjustment signal for adjusting whether the electronic valve of the hydraulic circuit valve assembly 16 is open / closed to the electronic valve of the hydraulic circuit valve assembly 16.

[0059] In the case of redundant braking, the auxiliary controller 17 generates and transmits the second motor control signal MCS2 based on the braking input PSS to provide redundant braking force to the auxiliary brake motor of the auxiliary braking device 15.

[0060] In this specification, PSS can be understood as an electronic signal generated based on the user's pedal input or a braking signal provided from a specific autonomous device, such as a pedal sensing signal (PSS).

[0061] In embodiments of this disclosure, the main controller 18 can be configured as a separate drive circuit physically distinct from the auxiliary controller 17. That is, according to this disclosure, even if the drive circuit performing the functions of the main controller 18 fails, the auxiliary drive circuit performing the functions of the auxiliary controller 17 appropriately performs redundant braking functions, thus ensuring redundancy.

[0062] Furthermore, the electronic brake according to embodiments of this disclosure may also include an electronic parking brake mounted on one or more wheels.

[0063] In embodiments of this disclosure, an electronic parking brake is illustrated as being integrally mounted on the two wheel brake units of the rear wheel.

[0064] The two electronic parking brakes are configured to be controlled by the first parking brake signal EPCS1 and the second parking brake signal EPCS2 of the main controller 18 and the auxiliary controller 17, respectively.

[0065] In embodiments of this disclosure, the secondary braking device 15 may be a pump with a smaller capacity or a smaller output compared to the primary braking device 14. Therefore, in the redundant case of braking by the secondary braking unit and the secondary braking device 15, the auxiliary control unit can brake the front wheels by supplying hydraulic pressure to the wheel braking units w3 and w4 via the secondary braking device 15, and the auxiliary control unit can brake the rear wheels by applying a second parking brake signal EPCS2 to the electronic parking brake of the rear wheels.

[0066] Next, refer to Figures 2 to 7 The description explains how the hydraulic circuit valve device 16 selectively transmits hydraulic pressure supplied from the main braking device and the auxiliary braking device 15 to multiple wheel braking units w1, w2, w3 and w4, and how it removes hydraulic pressure supplied to the multiple wheel braking units w1, w2, w3 and w4.

[0067] Figure 3 This is a diagram showing the hydraulic conditions generated in the brake backup system during startup.

[0068] like Figure 3 As shown, during startup, the first master brake valve opens to create a hydraulic path between the rear chamber of the master brake 14 and the reservoir 10, while the second master brake valve 142 closes to block the hydraulic path between the auxiliary brake 15 and the master brake 14. The front chamber of the master brake 14 can be filled with brake fluid flowing from the reservoir 10 through the check valve, depending on the rearward stroke of the master brake 14.

[0069] In this situation, the mixing valve opens, so each braking channel, together with the main braking device 14, forms a hydraulic path.

[0070] Figure 4 This is a diagram showing the hydraulic state during normal braking operation.

[0071] In this situation, normal braking operation, that is, the driver applies the brake input PSS to the pedal simulator or driving controller to generate the brake input PSS and inputs the brake input PSS to the main controller 18 and the auxiliary controller 17, means that the main controller 18 and the main braking device 14 are not malfunctioning.

[0072] Reference Figure 4 During normal braking operation, the piston of the main brake device 14 performs a forward stroke and generates hydraulic pressure in the brake fluid in the front chamber.

[0073] In this configuration, the first traction control valve 161 and the second main brake valve 142 remain closed. Furthermore, the second traction control valve 162 and the mixing valve 163 remain open.

[0074] Therefore, the hydraulic pressure transmitted through the front chamber of the main braking device 14 can be transmitted to multiple wheel braking units w1, w2, w3 and w4 through the corresponding braking channels.

[0075] In this configuration, the hydraulic pressure supplied to each of the wheel braking units w1, w2, w3, and w4 can be individually adjusted by opening / closing specific inlet valves, outlet valves, traction valves, and mixing valves, and by adjusting the main braking device 14 as needed.

[0076] Figure 5 This is a diagram showing the hydraulic conditions during normal braking and stopping operations.

[0077] In this situation, a normal braking stop operation, i.e., when the driver removes the brake input PSS (pedal return) applied to the pedal simulator or the driving controller generates a brake stop input and inputs the brake stop input to the main controller 18 and the auxiliary controller 17, means that the main controller 18 and the main braking device 14 are not malfunctioning.

[0078] Reference Figure 5 During normal braking and stopping, the piston of the master brake 14 performs a rearward stroke, and the brake fluid in the front chamber is refilled. That is, a negative pressure is generated in the front chamber of the master brake 14.

[0079] In this configuration, the first traction control valve 161 and the second main brake valve 142 remain closed. Furthermore, the second traction control valve 162 and the mixing valve 163 remain open.

[0080] Therefore, the brake fluid supplied to the multiple wheel braking units w1, w2, w3 and w4 can return to the front chamber of the main braking device 14 through the brake passages respectively.

[0081] In this case, by opening / closing specific inlet valves, outlet valves, traction valves, and mixing valves, and adjusting the main braking device 14 as needed, the hydraulic pressure can be individually adjusted for each of the wheel braking units w1, w2, w3, and w4.

[0082] Figure 6 This is a diagram showing the hydraulic state during redundant braking operation.

[0083] In this case, redundant braking operation, i.e., the state in which the driver applies the brake input PSS to the pedal simulator or driving controller to generate the brake input PSS and inputs the brake input PSS to the main controller 18 or the auxiliary controller 17, refers to a state in which one or more of the main controller 18 or the main braking device 14 malfunction.

[0084] Reference Figure 6 In redundant braking operations, hydraulic pressure is generated by the auxiliary braking device. In embodiments of this disclosure, the auxiliary braking device may be an oil pump. That is, the second motor control signal MCS2 is applied to the auxiliary brake motor of the auxiliary braking device 15, so the auxiliary braking device 15 can generate hydraulic pressure.

[0085] In this configuration, the first traction control valve 161 and the mixing valve 163 remain closed. Furthermore, the second traction control valve 162 and the second master brake valve 142 remain open.

[0086] Therefore, the hydraulic pressure generated by the auxiliary braking device 15 can be transmitted to a pair of wheel braking units w3 and w4 through a pair of braking channels, i.e., a braking circuit.

[0087] In embodiments of this disclosure, it is illustrated that, during redundant braking operation, hydraulic pressure generated by the auxiliary braking device 15 is supplied to wheel brake units w3 and w4 mounted on the front wheels of the vehicle. However, this disclosure is not limited thereto, and the mounting position of the wheel brake units to which hydraulic pressure is supplied during redundant braking operation can be changed if desired.

[0088] Furthermore, in embodiments of this disclosure, during redundant braking operations, electronic parking brakes (EPBs) 19_1 and 19_2 can be used to brake wheels that are not supplied with hydraulic pressure.

[0089] In other words, during redundant braking operation, the auxiliary controller 17 can generate the required braking force by operating all electronic parking brakes and auxiliary braking devices 15 according to the required braking input PSS.

[0090] For example, when the required braking input PSS is small, considering the life of the electronic parking brake, the hydraulic pressure generated by the auxiliary braking device 15 can be supplied to one pair of wheel brakes, and braking force can be applied to the other pair of wheel brakes without applying braking force.

[0091] In another embodiment of this disclosure, when the required braking force is sufficiently small, the hydraulic pressure generated by the secondary braking device 15 can be supplied to all four wheel braking units w1, w2, w3 and w4 by opening the mixing valve.

[0092] Figure 7 This is a diagram showing the hydraulic state during redundant braking and stopping operations.

[0093] In this situation, redundant brake stop operation, i.e., the state in which the driver removes the brake input PSS (pedal return) applied to the pedal simulator or the driving controller generates a brake stop input and inputs the brake stop input to the main controller 18 and the auxiliary controller 17, indicates that the main controller 18 and the main braking device 14 have failed.

[0094] Reference Figure 7 During redundant braking stop operation, the operation of the auxiliary braking device 15 is stopped. Hydraulic pressure supplied to the pair of wheel braking systems w3 and w4 can be returned to the reservoir according to the pressure gradient.

[0095] In the embodiment shown in the figure, the second main brake valve 142, the second traction control valve 162, the first auxiliary brake valve 151, or the second auxiliary brake valve 152 remain open. Furthermore, the mixing valve 163 remains closed.

[0096] Therefore, the brake fluid supplied to the pair of wheel braking systems w3 and w4 can be returned to each reservoir 10.

[0097] However, in this case, by opening / closing specific inlet valves, outlet valves, traction valves, and mixing valves, and adjusting the main braking device 14 as needed, the hydraulic pressure can be individually adjusted for each of the wheel braking units w1, w2, w3, and w4.

[0098] In addition, the auxiliary controller 17 can remove the braking force supplied to the other pair of wheels by controlling the electronic parking brake installed on the other pair of wheels.

[0099] As described above, according to this disclosure, normal braking control operations can be performed by the main controller 18 and the main braking device 14, and when the main controller 18 or the main braking device 14 fails, appropriate braking can be performed using the auxiliary controller 17 and the secondary braking device 15.

[0100] One point worth noting is that, compared to passing through Figure 8 Compared to the braking systems of the related technologies described herein, the electronic brake according to this disclosure does not employ a backup master cylinder that is directly connected to the pedal and manually generates hydraulic pressure, and utilizes space to install the auxiliary braking device 15.

[0101] In other words, according to this disclosure, as long as the secondary braking device 15 can be physically and electrically driven independently of the main controller 18, a redundant system can be safely provided, and the electronic parking brake can be used to supplement the insufficient braking force while the secondary braking device is installed. Although the secondary braking device has a smaller capacity than the main braking device 14, it can still appropriately generate the required brake hydraulic pressure, based on the specific consideration that it does not need to be a backup master cylinder for the manual control unit.

[0102] Furthermore, since the spare master cylinder is removed, the corresponding space can be used as space for installing the auxiliary braking device 15. The advantage is that the size of the entire electronic braking system can still maintain the size of the braking system of the relevant technology.

[0103] This disclosure provides an electro-hydraulic braking system that can appropriately provide redundant braking force when the driver is not driving or paying little attention to driving (such as autonomous driving or intelligent cruise control) and the main braking device fails, i.e., an electro-hydraulic braking system that provides so-called redundancy.

[0104] Furthermore, this disclosure provides an electro-hydraulic braking system that has a smaller, more space-saving size and is capable of performing the required redundant functions.

[0105] Although exemplary embodiments of this disclosure have been described for illustrative purposes, those skilled in the art will understand that various modifications, additions, and substitutions are possible without departing from the spirit and scope of the claimed invention. Therefore, exemplary embodiments of this disclosure have been described for the sake of brevity and clarity. The scope of the technical concept of these embodiments is not limited by the illustrations. Therefore, those skilled in the art will understand that the scope of the claimed invention is not limited to the embodiments explicitly described above, but is limited by the claims and their equivalents.

[0106] Cross-references to related applications

[0107] This application claims the benefit of priority to Korean Patent Application No. 10-2021-0090423, filed on July 9, 2021, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. An electro-hydraulic braking system, the electro-hydraulic braking system comprising: Multiple wheel braking units, the multiple wheel braking units being configured to provide braking force to multiple wheels of the vehicle; A main braking device, the main braking device including a main brake motor and configured to generate a first brake fluid pressure; A secondary braking device, the secondary braking device including a secondary brake motor and configured to generate a second brake oil pressure; A hydraulic circuit valve device configured to selectively transmit either the first brake oil pressure or the second brake oil pressure to the plurality of wheel brake units; A main controller configured to control the main brake motor based on brake input; as well as An auxiliary controller, wherein the auxiliary controller is configured to: The auxiliary brake motor is controlled based on the brake input; as well as When the main controller or the main braking device malfunctions, the hydraulic circuit valve device is controlled to transmit the second brake oil pressure to a portion of the plurality of wheel braking units. The second master brake valve is located between the reservoir and the front chamber positioned in front of the piston of the master brake device. The second master brake valve is configured to determine whether to transfer working fluid from the secondary brake to a portion of the plurality of wheel brake units based on whether the second master brake valve is open or closed. When the hydraulic pressure at the plurality of wheel braking units decreases and the second master brake valve opens, the working fluid is transferred from the front chamber to the reservoir via the auxiliary braking device.

2. The electro-hydraulic braking system according to claim 1, wherein, When either the main controller or the main braking device fails... The auxiliary brake motor is configured to operate based on a second motor control signal generated by the auxiliary controller. The auxiliary braking device is configured to transmit hydraulic pressure to one or more wheel braking units in a first portion of the plurality of wheel braking units, and The auxiliary controller is configured to use an electronic parking brake connected to one or more wheel brake units of the second part of the plurality of wheel brake units to control the braking force provided to the wheel brake units of the second part.

3. The electro-hydraulic braking system of claim 1, further comprising a pedal simulator fluidly separated from the hydraulic circuit valve device and configured to determine the magnitude of the force by which the driver depresses the brake pedal of the vehicle.

4. The electro-hydraulic braking system according to claim 3, wherein, The pedal simulator is fluidly separated from the reservoir.

5. The electro-hydraulic braking system according to claim 1, wherein, The main braking device has a double-acting piston-piston structure, which includes a piston disposed within the internal space of the main braking device and two hydraulic chambers separated by the piston. The auxiliary braking device includes an oil pump.

6. The electro-hydraulic braking system according to claim 1, further comprising a first auxiliary brake valve and a second auxiliary brake valve, the first auxiliary brake valve and the second auxiliary brake valve being disposed in parallel between the second main brake valve and the reservoir and configured to regulate the hydraulic pressure at the plurality of wheel brake units.

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