METHOD FOR CONTROLLING AN ESC-INTEGRATED BRAKING SYSTEM

Abstract

Method for controlling an ESC-integrated braking system, wherein the method comprises the following: when a failure in which no pressure can be built up in a master brake cylinder unit (40) is detected by the ESC-integrated braking system during braking of a vehicle, and When the pressure (PC1) of a pedal cylinder (22) is equal to or greater than the pressure (MC1) of the circuit based on the maintained braking force, the control unit (100) controls the specific oil pressure relief valves (51, 52, 53, 54, 55, 56) into an open state and then switches the state of the specific oil pressure relief valves (51, 52, 53, 54, 55, 56) into a mechanically locked state. characterized by Maintaining a braking force applied during braking by a control unit (100) by closing certain oil pressure relief valves (51, 52, 53, 54, 55, 56) to connect the master brake cylinder unit (40) and a flow channel of a circuit; furthermore comprehensive: after maintaining the braking force applied during braking, when the brake pedal (10) is released, Performing an activation control of the specific oil pressure relief valves (51, 52, 53, 54, 55, 56) in the open state by the control unit (100) according to a release degree of the brake pedal (10); or furthermore, comprehensively, that when maintaining the braking force applied during braking, the control unit (100) releases the maintenance of the braking force if a required braking force does not occur because the driver does not press the brake pedal (10) or the pressure of the pedal cylinder unit (20) is equal to or greater than the pressure of the circuit.

Description

GENERAL STATE OF TECHNOLOGY FIELD

[0001] Exemplary embodiments of the present disclosure relate to a method for controlling a braking system integrated into an electronic vehicle dynamics control (electronic stability control, ESC) and, in particular, a method for controlling an ESC-integrated braking system, wherein, in the event of a failure in a master brake cylinder unit where no pressure can be built up by an actuator, the state of the ESC-integrated braking system switches to a mechanical safety state in which a braking force is generated only by the pedal force of a driver, thus preventing a recoil phenomenon that occurs because a fluid mass formed in the master cylinder flows into a pedal simulator and thus a sudden pressure is formed in the pedal simulator. DISCUSSION OF THE STATE OF THE TECHNOLOGY

[0002] In general, a braking system includes an anti-lock braking system (ABS) to prevent a wheel from slipping during braking, a brake traction control system (BTCS) to prevent a drive wheel from slipping during sudden unintended acceleration or sudden acceleration of a vehicle, and an electronic stability control system (ESC) to keep the driving condition of a vehicle stable by combining the ABS and traction control and controlling the pressure of the brake fluid.

[0003] However, in the braking system, where the pressure of a master cylinder unit is controlled by an actuator (e.g., a motor), as in the ECS-integrated braking system, a failure can occur in which the pressure in the master cylinder unit cannot be controlled to generate braking pressure. For example, if the brake pressure cannot be controlled due to a failure of a position sensor (Hall sensor and rotary encoder) necessary for motor control, a failure of a motor current sensor, or damage to a motor, the braking system switches to a mechanical safety state in which braking force can only be generated by the pedal force of a driver via a pedal simulator.

[0004] When the ESC-integrated braking system is controlled normally, the driver's pedal force (or pedal feel) is generated by the rubber and spring of the pedal simulator. In this case, the pressure generated in the pedal simulator is much lower than the pressure generated in the master cylinder.

[0005] While the ESC-integrated braking system performs braking in a normal state, if the ESC-integrated braking system switches to its mechanical safety state due to a failure in the master cylinder unit, where the actuator (e.g., motor) cannot generate brake pressure, a fluid volume generated in the master cylinder unit flows into the pedal simulator, which has a lower pressure than the master cylinder. This reduces the braking force generated in the normal state and creates a sudden pressure in the pedal simulator. Consequently, a large shock, attributable to recoil, is applied to the driver.

[0006] Therefore, there is a need for a procedure capable of preventing recoil when the ESC-integrated braking system switches to the mechanical safety state while braking is being performed in the normal state.

[0007] The prior art technology is disclosed in published Korean patent application No. 10-1997-0000784 (published on January 21, 1997, under the title "Power Control Device for Automobiles"). CN 1 04 648 368 A discloses a method for controlling an ESC-integrated braking system with the features of the preamble of claim 1. US 6 464 307 B1 discloses another braking system. SUMMARY

[0008] Various embodiments are aimed at providing a method for controlling an ESC-integrated braking system, wherein, in the event of a failure in a master cylinder unit where no pressure can be generated by an actuator, the state of the ESC-integrated braking system switches to a mechanical safety state in which a braking force is generated only by the pedal force of a driver, thus preventing a recoil phenomenon that occurs because a fluid mass formed in the master brake cylinder flows into a pedal simulator and thus a sudden pressure is formed in the pedal simulator.

[0009] According to the invention, a method for controlling a braking system integrated into a vehicle dynamics control system (electronic stability control, ESC) comprises, when a failure in which no pressure can be built up in a master brake cylinder unit is detected by the ESC-integrated braking system during braking of a vehicle, maintaining a braking force applied during braking, by the control unit by closing certain oil pressure relief valves to connect the master brake cylinder unit and a flow channel of a circuit, and when the pressure (PC1) of a pedal cylinder due to a brake pedal pressed by a driver becomes equal to or greater than a pressure (MC1) of the circuit based on the maintained braking force, controlling the certain oil pressure relief valves into an open state by the control unit and then switching the state of the certain oil pressure relief valves into a mechanical locking state.

[0010] In one embodiment, the circuit means a flow channel with inlet valves and outlet valves for generating brake pressure in the respective wheel cylinders of the front and rear wheels via the specified oil pressure relief valves.

[0011] In one embodiment, the method further includes the immediate switching of the state of the certain oil pressure relief valves into the mechanical locking state by the control unit when the failure, in which no pressure can be built up in the master brake cylinder unit, is detected by the ESC-integrated braking system before the vehicle is braked.

[0012] In one embodiment, the method further includes, if a failure in which no pressure can be built up in the master brake cylinder unit is not detected by the ESC-integrated braking system before braking the vehicle, checking by the control unit whether a required braking force is generated by a pedal stroke sensor, and determining by the control unit that the required braking force has not been generated if a pedal stroke as a result of the check is 0, and performing a first position control to maintain the master brake cylinder unit in an initial state.

[0013] In one embodiment, the method further includes, if the pedal stroke is not 0 as a result of the test, calculating the required pressure corresponding to the pedal stroke value by the control unit and performing pressure control of the master brake cylinder unit according to the calculated required pressure by the control unit by driving an actuator of the master brake cylinder unit.

[0014] In one embodiment, the method further includes, if after performing the pressure control of the master brake cylinder unit no pressure of the master brake cylinder unit can be generated according to the calculated required pressure according to the pressure control, checking by the control unit whether the certain oil pressure relief valves are in a normal state, and immediately switching the state of the certain oil pressure relief valves to the mechanical locking state by the control unit if the certain oil pressure relief valves are not in a normal state as a result of the check of the states of the certain oil pressure relief valves.

[0015] In one embodiment, the specified oil pressure relief valves are a fourth oil pressure relief valve for connecting the master brake cylinder unit and a flow channel of a front wheel-side circuit and a fifth oil pressure relief valve for connecting the master brake cylinder unit and a flow channel of a rear wheel-side circuit.

[0016] In one embodiment, the method further includes, when the specified oil pressure relief valves are in the normal state, performing a switch-on control of the specified oil pressure relief valves in the closed state and controlling a sixth oil pressure relief valve to the closed state by the control unit, wherein the sixth oil pressure relief valve is a split block valve formed in a flow channel for connecting the specified oil pressure relief valves.

[0017] According to the invention, the method further includes, while maintaining the braking force applied during braking by closing the specific oil pressure relief valves to connect the master brake cylinder and the flow channel of the circuit, in the state in which a pedal stroke continues to be applied, controlling the specific oil pressure relief valves by the control unit to keep them in a closed state when the pressure of the pedal cylinder unit is less than the pressure of the circuit.

[0018] According to the invention, the method alternatively includes, after maintaining the braking force applied during braking by closing the specific oil pressure relief valves to connect the master brake cylinder and the flow channel of the circuit, performing an activation control for the specific oil pressure relief valves in the open state by the control unit according to a release degree of the brake pedal when the brake pedal is released.

[0019] In one embodiment, the control unit, when maintaining the braking force applied during braking by closing the specific oil pressure relief valves to connect the master brake cylinder and the flow channel of the circuit, releases the maintenance of the braking force when a required braking force does not occur because the driver is not pressing the brake pedal or the pressure of the pedal cylinder unit is equal to or greater than the pressure of the circuit.

[0020] In one embodiment, when the maintenance of the braking force is released, the control unit switches the state of the certain oil pressure relief valves to the mechanical locking state and activates a warning light. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is an exemplary diagram that schematically illustrates a configuration of an ESC-integrated braking system according to one embodiment. Fig. Figure 2 is a flowchart describing a method for controlling the ESC-integrated braking system according to one embodiment. Fig. Figure 3 is an exemplary diagram showing operating valves after pressure control in the forward direction in a normal state. Fig. 2 illustrated. Fig. Figure 4 is an exemplary diagram showing operating valves before switching to a mechanical safety state. Fig. 2 illustrated. DETAILED DESCRIPTION OF THE ILLUSTRATED EXECUTION FORMS

[0021] As is common in the relevant field, some exemplary embodiments may be illustrated in the drawings as functional blocks, units, and / or modules. It is apparent to those skilled in the art that these blocks, units, and / or modules may be physically implemented by electronic (or optical) circuits such as logic circuits, discrete components, processors, hard-wired circuits, memory elements, wired connections, and the like. If the blocks, units, and / or modules are implemented by processors or similar hardware, they may be programmed and controlled by software (e.g., code) to perform various functions discussed herein. Alternatively, each block, unit, and / or module may be implemented by dedicated hardware or as a combination of dedicated hardware for performing certain functions and a processor (e.g., a microcontroller).(one or more programmed processors and associated circuitry) to perform other functions. Each block, unit, and / or module of some exemplary embodiments can be physically separated into two or more interacting and discrete blocks, units, and / or modules without deviating from the scope of the invention. Furthermore, blocks, units, and / or modules of some exemplary embodiments can be physically combined to form more complex blocks, units, and / or modules without deviating from the scope of the invention.

[0022] In the following, a method for controlling an ESC-integrated braking system according to the present disclosure is described by means of various exemplary embodiments with reference to the accompanying drawings.

[0023] The thickness of lines or the size of elements shown in the drawings used to describe this specification may be exaggerated for the sake of clarity and convenience. The terms to be described below have been defined with consideration for their functions in this disclosure and may be modified according to the intent or practice of a user or operator. Accordingly, such terms should be interpreted based on the overall content of this specification.

[0024] Fig. Figure 1 is an exemplary diagram that schematically illustrates a configuration of an ESC-integrated braking system according to one embodiment.

[0025] As in Fig. Figure 1 illustrates a device for controlling an ESC-integrated braking system according to the present embodiment comprising a reservoir unit 80, a pedal cylinder unit 20, a motor 30, a master brake cylinder unit 40, wheel cylinders 111, 112, 121 and 122, oil pressure relief valves 51, 52, 53, 54, 55 and 56 and a control unit 100.

[0026] The reservoir unit 80 is connected to the upper end of the pedal cylinder unit 20 and stores oil.

[0027] In this case, the reservoir unit 80 can include a reservoir liquid measurement sensor Lu.

[0028] The pedal cylinder unit 20 generates oil pressure by applying pressure to a brake pedal 10.

[0029] The pedal cylinder unit 20 can include a pedal cylinder 22 and a pedal simulator 21 and form two chambers 20a and 20b. For example, the pedal cylinder unit 20 can have a first chamber 20a and a second chamber 20b.

[0030] For example, when a driver applies pedal force to the brake pedal 10, oil pressure is generated by the pedal cylinder 22. This oil pressure is supplied to a piston of the pedal simulator 21 and pressurizes the elastic body of the pedal simulator 21. Thus, the driver's pedal feel is translated into pressure by the reaction force of the pressurized elastic body.

[0031] The motor 30 is driven by an electrical signal output corresponding to the movement path of the brake pedal 10.

[0032] The control unit 100 can receive a rotation detection signal from the brake pedal 10 and control the driving of the motor 30.

[0033] The master brake cylinder unit 40 is driven by the motor 20, which is controlled by the control unit 100, and generates oil pressure and delivers the generated oil pressure to the wheel cylinders 111, 112, 121 and 122 to perform the braking of the wheels FL, FR, RL and RR respectively.

[0034] In this case, the control unit 100 could be an electronic control unit (ECU), that is, a representative control unit of a vehicle.

[0035] For example, when a driver presses the brake pedal 10, a pedal stroke sensor S / u detects a stroke of the brake pedal 10 and transmits the detected stroke to the control unit 100. The control unit 100 controls the oil pressure generated in the master brake cylinder unit 40 by controlling the motor 30 based on the stroke distance (or travel distance) of the brake pedal 10 detected by the pedal stroke sensor S / u.

[0036] In this process, the motor 30 operates under the control of the control unit 100 to generate brake oil pressure based on signals output by the pedal stroke sensor S / u and a pedal cylinder pressure sensor 92, while the brake pedal 10 is pressurized.

[0037] The master brake cylinder unit 40 can have a master brake piston 41 and form two chambers 40a and 40b. For example, the master brake cylinder unit 40 can have a third chamber 40a and a fourth chamber 40b.

[0038] The wheel cylinders 111, 112, 121 and 122 comprise a first wheel cylinder 111 for braking the left front wheel FL of a vehicle, a second wheel cylinder 112 for braking the right front wheel FR of the vehicle, a third wheel cylinder 121 for braking the left rear wheel RL of the vehicle and a fourth wheel cylinder 122 for braking the right rear wheel RR of the vehicle.

[0039] The device has inlet valves 61 to 64 for regulating the brake oil supplied to the first to fourth wheel cylinders 111, 112, 121 and 122, respectively. Outlet valves 71, 72, 73 and 74 for regulating the brake oil discharged from the first to fourth wheel cylinders 111, 112, 121 and 122 are provided in an oil pressure channel between the first to fourth wheel cylinders 111, 112, 121 and 122 and the reservoir unit 80.

[0040] The oil pressure relief valves 51, 52, 53, 54, 55, and 56 are provided in the oil pressure channels and are opened or closed under the control of the control unit 100. The oil pressure relief valves 51, 52, 53, 54, 55, and 56 can comprise the first through sixth oil pressure relief valves.

[0041] The first oil pressure relief valve 51 is provided in an oil pressure channel connecting the reservoir unit 80 and the first chamber 20a of the pedal cylinder unit 20, and adjusts the oil pressure by being opened or closed under the control of the control unit 100.

[0042] The second oil pressure relief valve 52 is provided in an oil pressure channel connecting the first chamber 20a of the pedal cylinder unit 20 and the fourth chamber 40b of the master brake cylinder unit 40, and adjusts the oil pressure by being opened or closed under the control of the control unit 100.

[0043] The third oil pressure relief valve 53 is provided in an oil pressure channel connecting the second chamber 20b of the pedal cylinder unit 20 and the third chamber 40a of the master brake cylinder unit 40, and adjusts the oil pressure by being opened or closed under the control of the control unit 100.

[0044] The fourth oil pressure relief valve 54 is provided in an oil pressure channel connecting the third chamber 40a of the master brake cylinder unit 40 and the first and second wheel cylinders 111 and 112, and adjusts the oil pressure by being opened or closed under the control of the control unit 100.

[0045] The fifth oil pressure relief valve 55 is provided in an oil pressure channel connecting the fourth chamber 40b of the master brake cylinder unit 40 and the third and fourth wheel cylinders 121 and 122, and adjusts the oil pressure by being opened or closed under the control of the control unit 100.

[0046] The sixth oil pressure relief valve 56 (or split block valve) is provided in an oil pressure channel connecting the fourth oil pressure relief valve 54 and the third and fourth wheel cylinders 121 and 122, and in an oil pressure channel connecting the fifth oil pressure relief valve 55 and the first and second wheel cylinders 111 and 112, and adjusts the oil pressure by being opened or closed under the control of the control unit 100.

[0047] In this case, the oil pressure channel connecting the fourth oil pressure relief valve 54 and the third and fourth wheel cylinders 121 and 122 is connected to the fourth chamber 40b of the master brake cylinder unit 40 and directs the oil pressure to the third and fourth wheel cylinders 121 and 122, which are mounted on the two rear wheels RL and RR, respectively. Furthermore, the oil pressure channel connecting the fourth oil pressure relief valve 54 and the third and fourth wheel cylinders 121 and 122 can include a second pressure sensor 95 for measuring the oil pressure. In this case, the second oil pressure sensor 95 can be omitted to reduce costs.

[0048] Furthermore, the oil pressure channel connecting the fifth oil pressure relief valve 55 and the first and second wheel cylinders 111 and 112 is connected to the third chamber 40a of the master brake cylinder unit 40 and directs the oil pressure to the first and second wheel cylinders 111 and 112, which are mounted on the two front wheels FL and FR, respectively. The oil pressure channel connecting the fifth oil pressure relief valve 55 and the first and second wheel cylinders 111 and 112 may also include a first pressure sensor 90 for measuring the oil pressure.

[0049] The first to sixth oil pressure relief valves 51, 52, 53, 54, 55 and 56 can be valves that are always in operation and can be configured as solenoid valves controlled by the control unit 100.

[0050] Furthermore, the sixth oil pressure relief valve 56 (or the split block valve) is a line-split valve and can adjust a spring force that can maintain a pressure of a certain value or more in the off state.

[0051] The structure of the ESC-integrated braking system, configured as described above, is described in general terms below. When a driver applies pedal force to the brake pedal 10, hydraulic pressure is generated by the pedal cylinder 20. This hydraulic pressure is then supplied to the pistons of the pedal simulator 21, pressurizing the elastic body of the pedal simulator 21. The reaction force of the pressurized elastic body provides pedal feel for the driver. The motor 30, controlled by the control unit 100, is driven to generate brake oil pressure based on signals from the pedal travel sensor S / u and the pedal cylinder pressure sensor 92 while the brake pedal 10 is pressed. The master brake cylinder unit 40 generates the hydraulic pressure through the master brake piston 41, which is moved back and forth by the motor 30.

[0052] A method for preventing the occurrence of a recoil phenomenon by controlling the oil pressure relief valves (hereinafter referred to simply as valves) before the ESC-integrated braking system switches to the mechanical safety state in the event of a failure in the master cylinder unit where the braking force cannot be controlled, while the ESC-integrated braking system is performing braking in the normal state, is described below with reference to the Fig. 2 to 4 described.

[0053] Fig. Figure 2 is a flowchart describing a method for controlling the ESC-integrated braking system according to one embodiment. Fig. Figure 3 is an exemplary diagram showing operating valves after pressure control in the forward direction under normal conditions. Fig. 2 illustrated. Fig. Figure 4 is an exemplary diagram showing operating valves before switching to a mechanical safety state. Fig. 2 illustrated.

[0054] With reference to Fig. 2 The control unit 100 checks whether brake pressure can be generated in the master brake cylinder unit 40 (S101).

[0055] For example, the control unit 100 is configured to check the state of the master brake cylinder unit 40 and the state of its actuator (i.e., motor) 30 in real time by using a variety of sensors (e.g., position sensor, pressure sensor, and current sensor). In the present embodiment, a description of a configuration for checking the state of the master brake cylinder unit 40, which is a deviation from the technical subject matter of this disclosure, is omitted.

[0056] If, as a result of the test in S101, no brake pressure can be generated in the master brake cylinder unit 40 (no in S101) (i.e., if a failure has already occurred in a standby state before braking is started), the control unit 100 immediately switches to the mechanical safety state and activates a warning light (S111).

[0057] If, as a result of the test in S101, a brake pressure can be generated in the standby state before braking begins (yes in S101), the control unit 100 checks whether a required braking force is generated by the pedal stroke sensor S / u (i.e., checks whether the pedal simulator is working when a driver presses the brake pedal) (S102).

[0058] If the result of the test in S102 is 0 pedal travel (yes in S102), this indicates that the required braking force was not generated (i.e., the state in which the pedal simulator is not operating because the driver is not pressing the brake pedal). Therefore, control unit 100 performs an initial position control (S103) (i.e., holds the master brake cylinder unit in an initial state).

[0059] If the result of the test in S102 is not 0 (no in S102), this indicates that the required braking force has been generated (i.e., the state in which the pedal simulator is operating because the driver is pressing the brake pedal). Therefore, the control unit 100 calculates the required pressure corresponding to the pedal travel value (S104) and performs pressure control corresponding to the calculated required pressure by driving the actuator (i.e., motor) 30 of the master brake cylinder unit 40 (S105).

[0060] When the master brake cylinder unit 40 and the actuator (i.e. motor) 30 are in their normal state, pressure (i.e. brake pressure) can be generated according to the pressure control (yes, in S106).

[0061] For example, if the master brake cylinder unit 40 and the actuator (i.e., motor) 30 are in their normal state, as in Fig. As illustrated in Figure 3, the generation of the required braking force is detected by the pedal stroke sensor S / u. Accordingly, in the state in which the first, third, fifth and sixth oil pressure relief valves 51, 53, 55 and 56 are operating, the control unit 100 moves the piston of the master brake cylinder unit 40 forward by driving the actuator (i.e. motor) 30 and thereby generates pressure.

[0062] If no pressure (i.e., brake pressure) can be generated according to the pressure control (no in S106), this means that a failure has occurred in the master brake cylinder unit 40 and the actuator (i.e., motor) 30 during braking. In this case, the control unit 100 checks whether a set of predetermined oil pressure relief valves (i.e., the fourth and fifth oil pressure relief valves 54 and 55) are in their normal state (S107).

[0063] If, as a result of the test in S107, the plurality of predetermined oil pressure relief valves (i.e., the fourth and fifth oil pressure relief valves 54 and 55) are not in their normal state (no in S107), this means a state in which no backpressure prevention operation can be carried out according to the present embodiment. Accordingly, the control unit 100 immediately switches the state of the predetermined oil pressure relief valves to the mechanical safety state and activates the warning light (S111).

[0064] If, on the other hand, as a result of the test in S107, the plurality of predetermined oil pressure relief valves (i.e., the fourth and fifth oil pressure relief valves 54 and 55) are in the normal state (yes in S107), the control unit 100 (i.e., performs a switch-on control in the closed state) controls the plurality of predetermined oil pressure relief valves (i.e., the fourth and fifth oil pressure relief valves 54 and 55) (S108). Furthermore, the control unit 100 controls the sixth oil pressure relief valve 56 (or the split block valve) (i.e., switches the state of the sixth oil pressure relief valve 56 to the closed state) (S109).

[0065] For your information: the fourth and fifth hydraulic pressure relief valves 54 and 55 are hydraulic pressure relief valves that connect the master brake cylinder unit 40 and the flow channels of a circuit and are closing valves. That is, a closing valve is a valve that is open under normal circumstances, when no control (i.e., activation control) is in operation, and switches to the closed state by the control (i.e., activation control). In contrast, each of the first and sixth hydraulic pressure relief valves 51 and 56 is a valve that is closed under normal circumstances, when no control (i.e., activation control) is in operation, and switches to the open state by the control (i.e., activation control).

[0066] For example, if a failure occurs in the normal state of the fourth and fifth oil pressure relief valves 54 and 55, in which no brake pressure can be generated by the master brake cylinder unit 40 (yes in S107), the control unit 100 switches on the warning light and switches off the output of the actuator (i.e. motor) 30 of the master brake cylinder unit 40 and simultaneously closes the fourth and fifth oil pressure relief valves 54 and 55 by the control (i.e. switch-on control) according to a pressure command value from a driver or a pressure generated in the pedal cylinder 20, and does not actuate the remaining oil pressure relief valves.

[0067] Furthermore, if the pressure (i.e., PC1 pressure) of the pedal cylinder unit 20, detected by the pedal cylinder pressure sensor 92 (PC1), in the state where pedal travel continues to be applied (i.e., pedal travel > 0), is less than the pressure (i.e., MC1 pressure) of a circuit (i.e., the flow channels of valves 61 to 64 and 71 to 74 for generating brake pressure in wheel cylinders 111, 112, 121, and 122), detected by the first pressure sensor 90 (MC1) (see S110), the control unit 100 continues to control (i.e., switch-on control in the closed state) the plurality of predetermined oil pressure relief valves (i.e., the fourth and fifth oil pressure relief valves 54 and 55) and to control (i.e., control in the closed state) the sixth oil pressure relief valve 56 (or the split block valve) (see S107 to S110).

[0068] If the driver also presses the brake pedal and the pressure develops into a state PC1>=MC1, the control unit 100 controls the fourth and fifth oil pressure relief valves 54 and 55 (e.g., sets the activation value to 0, i.e., controls the fourth and fifth oil pressure relief valves 54 and 55 to the open state), so that pressure generated in the pedal simulator 21 is supplied to the circuit side. Therefore, braking can be carried out via the brake pedal according to the required braking force input by the driver.

[0069] As described above, the control unit 100 also performs control (i.e., gradually performs an open-state activation control) of the fourth and fifth oil pressure relief valves 54 and 55 according to the driver's pressure command value (i.e., the required braking force), even in the event of a failure of the actuator (i.e., the motor) 30 of the master brake cylinder unit 40. Therefore, no recoil phenomenon occurs when the driver slowly releases the brake pedal because the pressure in the circuit is also gradually reduced based on the driver's braking intention.

[0070] This means that the control (i.e., activation control) of the plurality of predetermined oil pressure relief valves (i.e., the fourth and fifth oil pressure relief valves 54 and 55) and the continued control of the sixth oil pressure relief valve 56 (or split block valve) (S107 to S110) mean that the driver does not press the brake pedal (i.e., the required braking force does not occur) or the pressure (i.e., PC1 pressure) of the pedal cylinder unit 20, detected by the pedal cylinder pressure sensor 92 (PC1), is equal to or greater than the pressure (i.e., MC1 pressure) of the circuit (i.e., the flow channels of valves 61 to 64 and 71 to 74 for forming the brake pressure in the wheel cylinders 111, 112, 121 and 122), detected by the first pressure sensor 90 (MC1).

[0071] If the driver does not press the brake pedal (i.e., the required braking force does not occur) or if the pressure (i.e., PC1 pressure) of the pedal cylinder unit 20, detected by pedal cylinder pressure sensor 92 (PC1), is equal to or greater than the pressure (i.e., MC1 pressure) of the circuit (i.e., the flow channels of valves 61 to 64 and 71 to 74 for generating brake pressure in wheel cylinders 111, 112, 121 and 122), detected by the first pressure sensor 90 (MC1) (no in S110), the control unit 100 accordingly switches the state of the valves to the mechanical locking state and turns on the warning light (S111).

[0072] As described above, in the present embodiment, if the ESC-integrated braking system fails and the brake pressure in the master cylinder unit 40 cannot be controlled while the ESC-integrated braking system is performing normal braking, it does not immediately switch to the mechanical safety state. Instead, it controls the fourth and fifth hydraulic pressure relief valves 54 and 55 until a driver releases the brake pedal or the pressure of the pedal simulator 21 and the pressure on the circuit side are equal. Therefore, the present embodiment has the effect of preventing the occurrence of a recoil phenomenon.

[0073] According to one aspect of the present disclosure, in the event of a failure in the master cylinder unit, where the actuator cannot generate pressure, the ESC-integrated braking system switches to a mechanical safety state in which braking force is generated solely by the driver's pedal force. This prevents a recoil phenomenon that occurs when fluid generated in the master cylinder unit flows into the pedal simulator, thus creating a sudden pressure in the pedal simulator.

[0074] The present disclosure has been described above with reference to the embodiments illustrated in the accompanying drawings, but these embodiments are for illustrative purposes only. A person skilled in the art in the field to which this disclosure belongs will understand that various modifications and other equivalent embodiments are possible based on these embodiments. Accordingly, the scope of protection of this disclosure is to be determined by the following claims. Furthermore, an implementation described in this specification may be described, for example, as a method or process, device, software program, data stream, or signal. Even though this disclosure has been discussed only in connection with a single form of implementation (e.g., discussed only as a method), the discussed feature may also be implemented in another form (e.g., device or program).The device may be implemented as suitable hardware, software, or firmware. The method may be implemented in a device such as a processor, generally referred to as a processing device, including, for example, a computer, a microprocessor, an integrated circuit, or a programmable logic device. The processor is, among other things, a communication device such as a computer, a mobile phone, a mobile phone / personal digital assistant (“PDA”), and any other device that facilitates the communication of information between end users.

Claims

[1] Method for controlling an ESC-integrated braking system, the method comprising: when a failure in which no pressure can be built up in a master brake cylinder unit (40) is detected by the ESC-integrated braking system during braking of a vehicle, and When the pressure (PC1) of a pedal cylinder (22) is equal to or greater than the pressure (MC1) of the circuit based on the maintained braking force, the control unit (100) controls the specific oil pressure relief valves (51, 52, 53, 54, 55, 56) into an open state and then switches the state of the specific oil pressure relief valves (51, 52, 53, 54, 55, 56) into a mechanically locked state. characterized by Maintaining a braking force applied during braking by a control unit (100) by closing certain oil pressure relief valves (51, 52, 53, 54, 55, 56) to connect the master brake cylinder unit (40) and a flow channel of a circuit; furthermore comprehensive: after maintaining the braking force applied during braking, when the brake pedal (10) is released, Performing an activation control of the specific oil pressure relief valves (51, 52, 53, 54, 55, 56) in the open state by the control unit (100) according to a release degree of the brake pedal (10); or furthermore, comprehensively, that when maintaining the braking force applied during braking, the control unit (100) releases the maintenance of the braking force if a required braking force does not occur because the driver does not press the brake pedal (10) or the pressure of the pedal cylinder unit (20) is equal to or greater than the pressure of the circuit. [2] Method according to claim 1, wherein the circuit comprises a flow channel comprising inlet valves (61, 62, 63, 64) and outlet valves (71, 72, 73, 74) for generating a brake pressure in the respective wheel cylinders (111, 112, 121, 122) of the front wheels (FL, FR) and the rear wheels (HL, HR) via the specified oil pressure relief valves (51, 52, 53, 54, 55, 56). [3] Method according to claim 1, further comprising immediately switching the state of the certain oil pressure relief valves (51, 52, 53, 54, 55, 56) into the mechanical locking state by the control unit (100) when the failure in which no pressure can be built up in the master brake cylinder unit (40) is detected before braking of the vehicle by the ESC-integrated brake system. [4] The method of claim 3, further comprising: if a failure in which no pressure can be built up in the master brake cylinder unit (40) is not detected by the ESC-integrated braking system before the vehicle is braked, The control unit (100) checks whether a required braking force is generated by a pedal stroke sensor (S / u); and Determine by the control unit (100) that the required braking force has not been generated if the pedal stroke is 0 as a result of the test, and perform an initial position control to keep the master brake cylinder unit (40) in an initial state. [5] The method of claim 4, further comprising: if the pedal travel as a result of the test is not 0, Calculating the required pressure corresponding to the pedal stroke value by the control unit (100); and Performing pressure control of the master brake cylinder unit (40) according to the calculated required pressure by the control unit (100) by driving an actuator (30) of the master brake cylinder unit (40). [6] The method of claim 5, further comprising: If, after performing the pressure control of the master brake cylinder unit (40) according to the calculated required pressure, no pressure can be generated in the master brake cylinder unit (40) according to the pressure control, The control unit (100) checks whether the specified oil pressure relief valves (51, 52, 53, 54, 55, 56) are in a normal state; and The control unit (100) immediately switches the state of the specific oil pressure relief valves (51, 52, 53, 54, 55, 56) into the mechanical locking state if the specific oil pressure relief valves (51, 52, 53, 54, 55, 56) are not in the normal state as a result of checking the states of the specific oil pressure relief valves (51, 52, 53, 54, 55, 56). [7] Method according to claim 1, wherein the specified oil pressure relief valves (51, 52, 53, 54, 55, 56) comprise the following: a fourth oil pressure relief valve (54) for connecting the master brake cylinder unit (40) and a flow channel of a front wheel-side circuit and a fifth oil pressure relief valve (55) for connecting the master brake cylinder unit (40) and a flow channel of a rear wheel-side circuit. [8] Method according to claim 6, further comprising: when the specific oil pressure relief valves (51, 52, 53, 54, 55, 56) are in their normal state, Performing an activation control of certain oil pressure relief valves (51, 52, 53, 54, 55, 56) in the closed state by the control unit (100); and Controlling a sixth oil pressure relief valve (56) into a closed state by the control unit (100), wherein the sixth oil pressure relief valve (56) is a split block valve formed in a flow channel for connecting the specific oil pressure relief valves (51, 52, 53, 54, 55, 56). [9] Method according to claim 1, further comprising: when maintaining the braking force applied during braking, by closing the specific oil pressure relief valves (51, 52, 53, 54, 55, 56) to close the master brake cylinder unit (40) and the flow channel of the circuit, in a state where pedal stroke continues to be entered, Control to keep the specified oil pressure relief valves (51, 52, 53, 54, 55, 56) in a closed state by the control unit (100) when the pressure of the pedal cylinder unit (20) is less than the pressure of the circuit. [10] Method according to claim 1, wherein when the maintenance of the braking force is released, the control unit (100) switches the state of the certain oil pressure relief valves (51, 52, 53, 54, 55, 56) to the mechanical locking state and switches on a warning light. [11] ESC-integrated braking system, the system comprising: a master brake cylinder unit (40); Oil pressure relief valves (51, 52, 53, 54, 55, 56); a pedal cylinder unit (20); and a control unit (100), wherein, when a failure is detected by the ESC-integrated braking system during braking of a vehicle, in which no pressure can be built up in the master brake cylinder unit (40), the control unit (100) maintains a braking force applied during braking by closing certain oil pressure relief valves (51, 52, 53, 54, 55, 56) to connect the master brake cylinder unit (40) and a flow channel of a circuit; and wherein the control unit (100), when a pressure (PC1) of the pedal cylinder unit (20) by a brake pedal (10) pressed by the driver becomes equal to or greater than a pressure (MC1) of the circuit based on the maintained braking force, controls the certain oil pressure relief valves (51, 52, 53, 54, 55, 56) to an open state and then switches the state of the certain oil pressure relief valves (51, 52, 53, 54, 55, 56) to a mechanical locking state, wherein the control unit (100) after maintaining the braking force applied during braking by closing the specified oil pressure relief valves (51, 52, 53, 54, 55, 56) to connect the master brake cylinder unit (40) and the flow channel of the circuit, when the brake pedal (10) is released, an activation control of the specific oil pressure relief valves (51, 52, 53, 54, 55, 56) in an open state according to a release degree of the brake pedal (10); or The control unit (100) maintains the braking force applied during braking by closing the specific oil pressure relief valves (51, 52, 53, 54, 55, 56) to connect the master brake cylinder unit (40) and the flow channel of the circuit, and releases the maintenance of the braking force when a required braking force does not occur because the driver does not press the brake pedal (10) or the pressure of the pedal cylinder unit (20) is equal to or greater than the pressure of the circuit. [12] System according to claim 11, wherein the circuit comprises a flow channel comprising inlet valves (61, 62, 63, 64) and outlet valves (71, 72, 73, 74) for generating a brake pressure in the respective wheel cylinders (111, 112, 121, 122) of the front wheels (FL, FR) and the rear wheels (HL, HR) via the specified oil pressure relief valves (51, 52, 53, 54, 55, 56). [13] System according to claim 11, wherein the control unit immediately switches the state of the specified oil pressure relief valves (51, 52, 53, 54, 55, 56) to the mechanical safety state when the failure in which no pressure can be built up in the master brake cylinder unit (40) is detected by the ESC-integrated brake system before the vehicle is braked. [14] System according to claim 13, wherein the control unit (100), if a failure in which no pressure can be built up in the master brake cylinder unit (40) is not detected before braking the vehicle by the ESC-integrated braking system, checks whether a required braking force is generated by a pedal stroke sensor (S / u) and determines that the required braking force has not been generated if a pedal stroke as a result of the check is 0, and performs an initial position control to maintain the master brake cylinder unit (40) in an initial state. [15] System according to claim 14, wherein the control unit (100), when the pedal stroke is not 0 as a result of the test, calculates the required pressure corresponding to the pedal stroke value and performs pressure control of the master brake cylinder unit (40) according to the calculated required pressure by driving an actuator (30) of the master brake cylinder unit (40). [16] System according to claim 11, wherein the control unit (100) in a state in which a pedal stroke continues to be input, controls to keep the specified oil pressure relief valves (51, 52, 53, 54, 55, 56) in a closed state when the pressure of the pedal cylinder unit (20) is less than the pressure of the circuit.

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