DE102022104252A1 - Braking system for a vehicle capable of regenerative and hydraulic braking and method of controlling the same - Google Patents

Abstract

A braking system is configured to perform cooperative braking and/or a combination of regenerative braking and hydraulic braking. The system includes a master cylinder, a reaction disk of resilient material configured to compress the master cylinder, a rod assembly including an actuation rod, an elastomeric attachment unit, and an elastomer having one end attached to a portion of the actuation rod and the other end attached to the elastomeric attachment unit applied, an electric booster having a motor piston configured to compress a portion of the reaction disk to compress the master cylinder by adjusting a displacement of the motor piston, and an electric controller configured to control the electric booster and a controller to decelerate the To perform vehicle using regenerative braking and / or hydraulic braking.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority and benefit of Korean Patent Application No. 10-2021-0023791 , filed on February 23, 2021 and Korean Patent Application No. 10-2021-0059777 , filed May 10, 2021, the disclosure of which is incorporated herein by reference in its entirety.

TECHNICAL AREA

The present disclosure relates to a braking system of a vehicle capable of regenerative braking and hydraulic braking, and a method of controlling the same.

BACKGROUND

The statements in this section merely provide background information for the present disclosure and do not necessarily constitute related prior art.

Regenerative braking is a type of braking in which a motor operates as a generator that utilizes a vehicle's inertia and uses resistance generated by the motor drive as a braking force.

In the case of a hybrid electric vehicle (HEV), a regenerative braking unit and a hydraulic braking unit work together to decelerate the vehicle (hereinafter “cooperative braking”), thereby providing stable braking force to the vehicle.

The vehicle further includes an electric boost unit to increase a driver's pedaling effort. The electric boosting unit uses torque of an electric motor provided in the electric boosting unit to boost a force applied from an operating rod to the inside of a master cylinder. In generating a pedal feel, the electric amplification unit is configured to impart a desired pedal feel to the driver. In particular, the electrical amplification unit is configured to generate an appropriate amount of pedaling force corresponding to one pedal stroke when a reaction disc is compressed by the electrical amplification unit.

Meanwhile, when a vehicle with a conventional cooperative braking function performs regenerative braking, Electronic Stability Control (ESC) is deployed to reduce hydraulic pressure during regenerative braking by an amount that is compensated for by the regenerative braking. To this end, conventional vehicles require an ESC with a specification that enables cooperative control of regenerative braking and hydraulic braking. Concretely, the ESP requires a pressure reducing device such as an accumulator to reduce the hydraulic pressure, which requires a higher specification for the ESP. This can lead to an increase in costs.

In addition, when regenerative braking is disabled while a vehicle with a conventional cooperative braking function is performing cooperative braking, the amount of hydraulic oil in the braking system is increased using ESC to increase the braking force of the hydraulic braking. A pump is activated to draw oil from the master cylinder to increase the amount of hydraulic oil in the braking system. As a result, the pressure generated in the master cylinder is reduced, and the driver has an unnatural feeling that the pedaling force is reduced.

In vehicles equipped with a regenerative braking unit and a prior art hydraulic braking unit, a pedal force in regenerative braking is generated only by a pedal spring. Accordingly, when an available regenerative braking time is long, the driver feels a break in pedal force, so there is a problem that sensitivity quality deteriorates.

Further, in prior art regenerative braking of vehicles using electronic stability control (ESC), hydraulic pressure is reduced by the braking compensation amount according to the regenerative braking. To this end, the prior art vehicles require an ESC with specifications that can perform cooperative control of regenerative braking and hydraulic braking. Specifically, an ESC additionally requires a decompressor such as an accumulator to reduce hydraulic pressure, so that the specification of the ESC is increased. Accordingly, there is a problem of an increase in manufacturing cost.

SUMMARY

In view of the above, the present disclosure primarily aims to reduce regenerative braking force by receiving a regenerative braking interrupt signal and unnatural pedal feel is eliminated, which is generated when hydraulic braking force is increased by an amount corresponding to the decrease in regenerative braking force.

The problems to be solved in the present disclosure are not limited to the above problems, and other problems not mentioned here will be clearly understood by those skilled in the art from the following description.

According to one aspect of this application, a braking system configured when braking a vehicle to perform one or more cooperative braking or a combination of regenerative braking and hydraulic braking includes a master cylinder; a reaction disk made of an elastic material and configured to compress the master cylinder; a rod assembly including an operating rod whose displacement is adjusted based on an amount of force applied to a brake pedal, an elastomeric mounting unit, and an elastomer having one end abutted against a part of the operating rod and the other end abutting the elastomeric mounting unit; an electric booster having a motor piston configured to compress at least a portion of the reaction disk for compressing the master cylinder by adjusting a displacement of the motor piston; and an electric controller configured to control the electric booster and perform control to brake the vehicle using at least one of regenerative braking and hydraulic braking.

When the electric controller brakes the vehicle by performing at least regenerative braking between regenerative braking and hydraulic braking, the electric controller may command the electric amplifier to compress the reaction disk when regenerative braking is disabled.

The actuating rod may be configured to compress a central portion of the reaction disk and the motor piston may be configured to compress an outer periphery of the reaction disk.

When the engine piston compresses the reaction disc, the central part of the reaction disc may protrude toward the operating rod depending on a degree of compression, thereby forming a protruding portion.

If the protruding portion abuts against the operating rod when the brake pedal is depressed, the pressure exerted by the reaction disc on the operating rod can increase with increasing pressure exerted on the reaction disc by the engine piston, and at the same time, a contact area between the reaction disk and the operating rod.

If the hydraulic pressure is maintained in the master cylinder, if the motor piston moves further toward the reaction disk than the operating rod and the displacement of the motor piston and the displacement of the operating rod are equal, an amount of pedal force can be maintained no matter how strong the master cylinder compressed by the reaction disc.

The elastomer can have at least one spring between the spring and a damper.

According to one aspect of this application, a method for controlling a braking system configured to perform cooperative braking and/or a combination of regenerative braking and hydraulic braking when braking a vehicle includes: (a) when a pedal is actuated, calculating a total braking force, required to brake the vehicle based on pedal travel measured by a pedal travel sensor; (b) calculating a required regenerative braking force based on the total required braking force; (c) operating a regenerative braking unit to provide a braking force corresponding to the required regenerative braking force; (d) determining whether or not to terminate regenerative braking; (e) if it is determined that regenerative braking needs to be stopped, calculating a required hydraulic braking force corresponding to stopping regenerative braking; (f) calculating a required displacement of an engine piston corresponding to the required hydraulic braking force; and (g) operating an electrical amplifier to compress a reaction disc by moving the motor piston according to the required displacement.

The motor piston can be made of an elastic material.

The engine piston may be configured to compress an outer periphery of the reaction disk.

In step (g), when the engine piston can compress the reaction disc, an amount of reaction force generated is constant.

In step (f), the required displacement may be calculated based on whether the reaction disk abuts the operating rod, the displacement of which is adjusted based on an amount of force applied to a brake pedal.

As explained above, according to this embodiment, the braking system of a vehicle capable of regenerative and hydraulic braking and the method for controlling the same using an elastomer whose one end is fixed and which provides pedal feel to the driver and a reaction disc made of an elastic material to prevent the driver from having an unnatural pedal feeling when a regenerative braking force decreases but a hydraulic braking force increases while the total braking force remains constant.

The aim of the present disclosure is to provide a braking system with an improved sensitivity quality in regenerative braking and a method for controlling the braking system.

Another object of the present disclosure is to provide a braking system that can be equipped with an ESC of normal specifications and is not limited to the maximum boost ratio of an electric boosting unit, and a method for controlling the braking system.

According to a second embodiment of the present disclosure, there is an effect that when regenerative braking is performed, pedaling force is adjusted using a pedal spring and a damper, there is an effect that pedal decoupling decreases and sensitivity quality increases.

Further, when regenerative braking is performed, hydraulic pressure is adjusted by an electric booster unit to correspond to a braking compensation amount by regenerative braking. Accordingly, since common ECSs are applied to a vehicle without a specific ESC, there is an effect that the manufacturing cost of a vehicle decreases.

character list

• 1 12 is a cross-sectional view of a braking system according to an embodiment of the present disclosure.
• 2A and 2 B 12 are schematic diagrams for explaining a relationship among a reaction disk made of elastic material, an operating rod, a motor piston, and a pedaling force.
• 3 12 is a graph for explaining a relationship among total pedal force, pedal force of an elastomer, pedal force of a reaction disk, regenerative braking force, and hydraulic braking force versus time if regenerative braking is disabled during braking when the electronic control unit alone performs regenerative braking .
• 4A-4C are schematic diagrams to explain how the process works at the starting point, time t ₁₃ , and time t ₁₄ off 3 .
• 5 Fig. 12 is a graph for explaining a relationship among the total pedal force, a pedal force of an elastomer, a pedal force of a reaction disc, a regenerative braking force, and a hydraulic braking force versus time if the pedaling effort increases while regenerative braking is disabled during braking when the electric Control unit alone performs the regenerative braking.
• 6A-6C are schematic diagrams to explain how the process works at the starting point, time t ₂₃ and time t ₂₄ off 5 .
• 7 Fig. 12 is a graph for explaining a relationship among total pedal force, pedal force of an elastomer, pedal force of a reaction disk, regenerative braking force, and hydraulic braking force versus time if regenerative braking is disabled during braking when the electric control unit performs regenerative braking and a performs hydraulic braking.
• 8A-8C are schematic diagrams to explain how the process works at the starting point, time t ₃₄ and time t ₃₅ off 7 .
• 9 is a graph for explaining a relationship among the total pedal force, a pedal force of an elastomer, a pedal force of a reaction disc, a regenerative braking force, and a hydraulic braking force versus time if the pedal force increases while regenerative braking is disabled during braking when the electric Control unit performs regenerative braking and hydraulic braking.
• 10A-10C are schematic diagrams to explain how the process works at the start point, time t ₄₄ and time t ₄₅ off 9 .
• 11 1 is a flow diagram of a method for controlling a braking system according to an embodiment of the present disclosure.
• 12 12 is a conceptual diagram showing the initial state of a braking system according to a second embodiment of the present disclosure;
• 13 12 is a conceptual diagram showing a dead stroke state of the brake system according to the second embodiment of the present disclosure;
• 14A 13 is a conceptual diagram showing a first regenerative braking mode state of the braking system according to the second embodiment of the present disclosure;
• 14B 12 is a conceptual diagram showing the state when a second regenerative braking mode of the braking system according to the second embodiment of the present disclosure is started;
• 14C 12 is a conceptual diagram showing the state after the start of the second regenerative braking mode of the brake system according to the second embodiment of the present disclosure;
• 15 12 is a graph showing the relationship between a pedal stroke and a pedal force in each period in a regenerative braking mode of the brake system according to the second embodiment of the present disclosure;
• 16A 12 is a conceptual diagram showing a first hydraulic braking mode state of the braking system according to the second embodiment of the present disclosure;
• 16B 13 is a conceptual diagram showing the state when a second hydraulic braking mode of the braking system according to the second embodiment of the present disclosure is started;
• 16C 14 is a conceptual diagram showing the state after starting the second hydraulic braking mode of the braking system according to the second embodiment of the present disclosure;
• 17 12 is a graph showing the relationship between a pedal stroke and a pedal force in each period in a hydraulic braking mode of the brake system according to the second embodiment of the present disclosure;
• 18 12 is a flowchart showing a method for controlling the brake system according to the second embodiment of the present disclosure;
• 19 14 is a flowchart showing a control procedure in the second regenerative braking mode state of the braking system according to the second embodiment of the present disclosure;
• 20 13 is a cross-sectional view of a brake system according to a third embodiment of the present disclosure;
• 21 Fig. 12 is a schematic diagram illustrating the relationship between an elastic reaction disk, an operating rod and a motor piston, and a pedaling force;
• 22 Fig. 12 is a graph showing the relationship between a total pedal force, a pedal force of an elastomer, a pedal force of a reaction disk, a regenerative braking force, and a hydraulic braking force over time when regenerative braking is stopped in a situation where a control unit is only activated during braking performs regenerative braking;
• 23 Fig. 12 is a schematic diagram showing an operation at a starting point and times t ₁₃ and t ₁₄ in 22 represents;
• 24 Fig. 12 is a graph illustrating the relationship among total pedal force, pedal force of an elastomer, pedal force of a reaction disc, regenerative braking force, and hydraulic braking force over time when a depression amount increases while regenerative braking is stopped in a situation where a control unit is braking performs only regenerative braking;
• 25 Fig. 12 is a schematic diagram showing an operation at a starting point and times t ₂₃ and t ₂₄ in 24 represents;
• 26 Fig. 12 is a graph illustrating the relationship among total pedal force, pedal force of an elastomer, pedal force of a reaction disc, regenerative braking force, and hydraulic braking force versus time when regenerative braking is stopped in a situation where a control unit controls regenerative braking and hydraulic braking during the braking;
• 27 FIG. 12 is a schematic diagram showing an operation at a starting point t ₃₄ and t ₃₅ in 26 indicates;
• 28 Fig. 12 is a graph illustrating the relationship among total pedal force, pedal force of an elastomer, pedal force of a reaction disc, regenerative braking force, and hydraulic braking force over time when a depression amount increases while regenerative braking is stopped in a situation where a control unit is braking performs both regenerative braking and hydraulic braking;
• 29 12 is a schematic diagram showing an operation at a starting point t ₄₄ and t ₄₅ in 28 illustrated; and
• 30 14 is a flow chart of a method for controlling a brake system according to a third embodiment of the present disclosure.

DETAILED DESCRIPTION

1 12 is a cross-sectional view of a braking system according to an embodiment of the present disclosure.

Referring to 1 , rod assembly 60 includes an actuating rod 12, an elastomer 17, and an elastomeric mounting portion 16.

The operating rod 12 is a medium through which the driver's pedaling effort is transmitted to the reaction disk 420 . One end of the operating rod 12 is connected to the pedal 11 . The actuating rod 12 may compress the master cylinder 14 by forcing the reaction disk 420 toward the master cylinder 14 along with the motor piston 28 . In an initial state where the pedal 11 starts to be operated, the other end of the operating rod 12 may be separated from the reaction disk 420. When the pedal 11 is depressed, the other end of the operating rod 12 moves forward towards the reaction disc 420.

The elastomer 17 is arranged so that one end abuts the operating rod 12 and the other end abuts the elastomer mounting part 16 . The elastomer 17 generates an elastic force when the operating rod 12 moves. When the driver actuates the pedal 11, the actuating rod 12 moves towards the reaction disc 420 and compresses the elastomer 17. The compressed elastomer 17 generates a reaction force, called an elastic force, which gives pedal feel to the rider. Since the other end of the elastomer 17 is arranged to abut against the elastomer attachment portion 16 , the elastomer 17 is affected only by displacement of the operating rod 12 . Even if no reaction force is generated from the reaction disk 420 because the operating rod 12 does not abut against the reaction disk 420, the rider can have pedal feeling by the reaction force of the elastomer 17. Since the elastomer 17 is bonded to the elastomer attachment portion 16 rather than to another location such as the engine piston 28, the rider does not have an unnatural pedal feel even at the moment the pressure in the master cylinder 14 changes.

The elastomer 17 can consist of a spring or a combination of a spring 171 and a damper 172 . In this disclosure, the spring 171 and damper 172 are shown as being connected in series, but not necessarily limited thereto, and the spring 171 and damper 172 may also be connected in parallel.

The elastomer attachment portion 16 is attached to the housing 30 and at least a portion of the elastomer 17 is attached to one side of the elastomer attachment portion 16 . The elastomer attachment portion 16 is shaped to support the elastomer 17 when the elastomer 17 is compressed by the rider's pedaling force.

When the electric control unit 59 performs hydraulic braking, the disk unit 42 supplies hydraulic pressure to a plurality of wheel brakes (not shown) by compressing the master cylinder 14 . Disk assembly 42 includes a reaction disk 420 and a reaction disk container 422.

The reaction disc 420 is configured to be compressed by the actuator rod 12 or motor piston 28 . 1 of the present disclosure shows that reaction disk 420 and engine piston 28 are in contact with one another. However, if no brake request signal is generated by the electrical control unit 50, this may mean that the motor piston 28 is separated from the reaction disc 420.

The reaction disk 420 may be configured such that an outer periphery of the reaction disk 420, ie, its outer periphery, is compressed by the motor piston 28 and the central portion of the reaction disk 420 is compressed by the actuating rod 12. For this purpose, a longitudinal section of the motor piston 28 may be approximately ring-shaped, and the operating rod 12 may pass through a hollow portion formed in the center of the motor piston 28. In this case, the actuating rod 12 and the reaction disc 420 are coaxial arranged. However, the present disclosure is not so limited, and any braking system having a device capable of compressing the reaction disc 420 by operating the pedal 11 and driving the motor 22 may be incorporated into this disclosure.

The reaction disk 420 is made of a compressible elastic material. For example, at least a portion of reaction disc 420 may be made of a rubber material. When the reaction disc 420 is compressed by the actuating rod 12 or the motor piston 28, a reaction force generated by the compression force is transmitted to the rider through the actuating rod 12 and forms part of the rider's pedal feel.

The reaction disk container 422 is shaped to receive at least a portion of the reaction disk 420 in a space defined therein. When one side of the reaction disk canister 422 is compressed by one or more of the actuating rod 12 and motor piston 28, the other side of the reaction disk canister 422 compresses the actuating rod 13.

The total pedal force made available to the driver can be determined as the sum of the pedal force generated by the reaction force against the pressing force of the reaction disc 420 and the pedal force generated by the reaction force against the pressing force of the elastomer 17 .

The electrical control unit 50 generates a braking request signal based on a pedal signal transmitted from a pedal travel sensor (not shown). The brake demand signal is an electrical signal that enables at least a portion of a plurality of wheel brakes (not shown) to generate a braking force.

The electronic control unit 50 calculates the total braking force required to brake the vehicle based on the pedal signal. In addition, the electrical control unit 50 determines whether to use regenerative braking or hydraulic braking, or both, and applies regenerative braking force and controls the electric boost unit 20 differently depending on whether using regenerative braking and/or hydraulic braking will or not. The required total braking force can be the sum of hydraulic braking force and regenerative braking force. A variety of braking modes can be set. For example, the electric control unit 50 can decelerate the vehicle by using a hydraulic braking mode in which only hydraulic braking force is used, a regenerative braking mode in which only regenerative braking force is used, and a cooperative braking mode in which both hydraulic braking force and regenerative braking force is also used.

2 Fig. 12 is a schematic diagram for explaining the relationship among a reaction disk made of an elastic material, an operating rod, a motor piston, and a pedaling force.

2A Fig. 12 is a schematic diagram illustrating pedal force versus displacement of operating rod 12 when displacement of reaction disc 420 does not vary. 2 B 12 is a schematic diagram illustrating pedal effort versus the amount of force applied to master cylinder 14 when the relative displacement of motor piston 28 and actuating rod 12 is constant.

Referring to 2A It can be seen that the pedaling force increases as the operating rod 12 moves toward the reaction disk 420 and that the pedaling force decreases as the operating rod 12 moves in the opposite direction. However, the driver's pedal feeling hardly changes when the difference between the displacement of the operating rod 12 and the displacement of the reaction disk 420 is within a certain range. This is attributed to an elastic material property of reaction disk 420 .

Referring to 2 B If the difference between the displacement of the operating rod 12 and the displacement of the reaction disk 420 is constant and the hydraulic pressure in the master cylinder 14 is increased by compressing the reaction disk 420, the driver's pedal feel increases with the hydraulic pressure in the master cylinder 14 and not with the displacement of the engine piston 28 and the displacement of the actuating rod 12.

3 Fig. 12 is a graph for explaining a relationship among total pedal force, pedal force of an elastomer, pedal force of a reaction disc, regenerative braking force, and hydraulic braking force versus time when regenerative braking is disabled during braking while the electric control unit alone performs regenerative braking performs. 4 FIG. 12 is a schematic diagram for explaining the operation at the starting point, time t ₁₃ and time t ₁₄ of FIG 3 .

Referred to below in the diagrams in the 3 , 5 , 7 and 9 L ₁ is the total pedal force, L ₂ is the elastomer 17 pedal force, L ₃ is the reaction disk 420 pedal force, L ₄ is the regenerative braking force, and L ₅ is the hydraulic braking force.

4A shows the process at the starting point of 3 , 4B shows the process at time t ₁₃ from 3 , and 4C shows the process at time t ₁₄ from 3 .

The starting point of 3 is a point in time r ₁₁ at which the driver starts to operate the pedal 11 and at which the entire pedaling force L ₁ is generated. Since the operating rod 12 is separated from a central part 423 of the reaction disk 420, the pedaling force L ₃ caused by the reaction force of the reaction disk 420 is not generated.

In the time between the starting point and time t ₁₁ , which is an initial period in which the driver operates the pedal 11, no braking force is generated. During this period, the pedaling force L ₂ generated by the compression of the elastomer 17 gradually increases.

The period between time t ₁₁ and time t ₁₂ is a period in which the corresponding braking force is generated as the pedal 11 is increasingly operated by the driver. 3 12 shows that the electric controller 50 initiates the regenerative braking mode to decelerate the vehicle in this period in which the hydraulic braking force L ₅ is not generated but the regenerative braking force L ₄ is gradually increasing.

The period between time t ₁₂ and time t ₁₃ is a period in which the driver's effort on the pedal 11 remains constant. During this period, the amount of braking force required by the driver does not change, and therefore the regenerative braking force L ₄ also remains constant. As in 4B As shown in FIG. 1, motor piston 28 compresses reaction disk 420 at time t ₁₃ causing the displacement of disk assembly 42 to move from d ₁₁ to d ₁₂ as shown in FIG 4 shown, but to such an extent that the hydraulic braking force L ₅ is not generated. The middle part 423 of the reaction disc 420 protrudes further than in due to the pressure exerted by the motor piston 28 4A , but is still not on the actuating rod 12.

The period between time t ₁₃ and time t ₁₄ is a period in which the electronic control unit 50 disables the regenerative braking mode and initiates the hydraulic braking mode. In this period, the regenerative braking force L ₄ is decreased and the hydraulic braking force L ₅ is increased by an amount corresponding to the decrease in braking force. The period between time t ₁₃ and time t ₁₄ is a period in which the hydraulic braking force L ₅ is increased. In the braking system according to an embodiment of the present disclosure, the electric brake booster unit 20 is driven to generate hydraulic braking force that moves the motor piston 28 from d ₁₂ to d ₁₃ and compresses the master cylinder 14 in the period between time t ₁₃ and time t ₁₄ . As in 4C As shown, at time t ₁₄ the displacement of the actuator rod 12 does not change from r ₁₂ , only the displacement of the motor piston 28 changes. Since the actuating rod 12 is still not in contact with the reaction disk 420, the total pedaling force L ₁ is only influenced by the pedaling force L ₂ of the elastomer 17 . Therefore, the driver does not have an unnatural feeling during the period that the hydraulic braking force is increasing. During the entire period, the total pedaling force L ₁ is equal to the pedaling force L ₂ of the elastomer 17 because the operating rod 12 is not in contact with the middle part 423 of the reaction disc 420 .

5 12 is a graph for explaining a relationship among total pedal force, pedal force of an elastomer, pedal force of a reaction disk, regenerative braking force, and hydraulic braking force versus time if the amount of pedal effort increases while regenerative braking is disabled during braking when the electronic control unit alone carries out the regenerative braking. 6 FIG. 12 is a schematic diagram for explaining the operation at the starting point, time t ₂₃ and time t ₇₄ of FIG 5 .

6A shows how the operation at the starting point of 5 , 6B shows the operation at time t ₂₃ of 5 , and 6C shows the operation at time t ₂₄ from 5 . Here, the operation of the braking system in the period between the starting point and time t ₂₃ in the in 5 13 is similar to the operation in the period between the start point and time t ₁₃ , so a description thereof is omitted.

At time t ₂₃ the electronic control unit 50 disables the regenerative braking mode and begins to adjust the hydraulic braking mode. In the period between time t ₂₃ and time t ₂₄ , the regenerative braking force L ₄ decreases and the hydraulic braking force L ₅ increases. As in 5 As shown, during this period the driver increases the amount of pedaling effort and therefore the required hydraulic braking force L ₅ becomes greater than the maximum amount of existing braking force L ₄ .

The amount of increase in hydraulic braking force L ₅ in the in 5 The period shown between time t ₂₃ and time t ₂₄ is greater than in the 3 illustrated period between time t ₁₃ and time t ₁₄ .

Nevertheless, the brake system according to an embodiment of the present disclosure prevents the driver from having an unnatural pedal feel.

As in 6B and 6C As shown, the displacement of the actuating rod 12 moves from r ₂₂ to r ₂₃ as the driver increases pedal force. Also, when the electric booster unit 20 is driven, the motor piston 28 compresses the disc unit 42, causing the displacement of the disc unit 42 to move from d ₂₂ to d ₂₃ and compressing the master cylinder 14, thereby generating hydraulic pressure. there as in 6C the operating rod 12 and the central part 423 of the reaction disk 420 do not abut, only the pedaling force of the elastomer 17 acts on the driver. Accordingly, despite a change in hydraulic pressure in the master cylinder 14, the driver does not have unnatural pedal feeling.

7 Fig. 12 is a graph for explaining a relationship among total pedal force, pedal force of an elastomer, pedal force of a reaction disc, regenerative braking force, and hydraulic braking force versus time if regenerative braking is disabled during braking when the electric control unit has regenerative and hydraulic braking performed. 8th FIG. 12 is a schematic diagram for explaining the operation at the starting point, time t ₃₄ and time t ₃₅ of FIG 7 .

8A shows the process at the starting point of 7 , 8B shows the process at time t ₃₄ from 8th , and 4C shows the process at time t ₃₅ from 7 .

The starting point of 7 is a point in time when the driver starts to operate the pedal 11, at which the operating rod 12 is positioned at r ₃₁ and the total pedaling force L ₁ is generated. Since the operating rod 12 is separated from a central part 423 of the reaction disk 420, the pedaling force L ₃ caused by the reaction force of the reaction disk 420 is not generated.

In the period between the starting point and time t ₃₁ , which is an initial period in which the driver operates the pedal 11, no braking force is generated. During this period, the pedaling force L ₂ generated by the compression of the elastomer 17 gradually increases.

The period between time t ₃₁ and time t ₃₂ is a period in which the corresponding braking force is generated while the amount of effort on the pedal 11 by the driver increases. 7 12 shows that the electronic control unit 50 first initiates the regenerative braking mode to decelerate the vehicle in this period in which the hydraulic braking force L ₅ is not being generated but the regenerative braking force L ₄ is gradually increasing.

The period between time t ₃₂ and time t ₃₃ is a period in which the hydraulic braking force L ₅ is being generated as it is determined that the electronic control unit 50 should initiate the hydraulic braking mode, including more effort on the pedal 11 by the driver. During this period, the regenerative braking force L ₄ is maintained, but the electric booster unit 20 is driven to compress the motor piston 28 and increase hydraulic pressure supplied to a plurality of wheel brakes (not shown). In this process, the operating rod 12 moves further towards the master cylinder 14 and compresses the protruding central part 423 of the reaction disk 420. When the actuating rod 12 rests against the central part 423 of the reaction disc 420, the driver feels an additional pedaling force _L3 . The total pedaling force L ₁ is the sum of the pedaling force L ₂ of the elastomer 17 and the pedaling force L ₃ of the reaction disc 420.

The period between time t ₃₃ and time t ₃₄ is a period in which the amount of driver's effort on the pedal 11 is maintained. During this period, the amount of braking force required by the driver does not change, and therefore the regenerative braking force L ₄ and the hydraulic braking force L ₅ also remain constant. As in 8B As shown in FIG. 1, the motor piston 28 is compressing the reaction disc 420 at a time t ₃₄ where the displacement of the disc assembly 42 is moving to d ₃₂ as in FIG 8th shown, and passes the point d ₀ where the hydraulic braking force L ₅ starts to generate. The middle part 423 of the reaction disk 420 protrudes further than in due to the pressure exerted by the engine piston 28 8A and lies against the actuating rod 12. In this period, the driver increases the amount of pedal effort to generate the hydraulic braking force L ₅ and therefore the displacement of the operating rod 12 also moves to r ₃₂ .

The period between time t ₃₄ and time t ₃₅ is a period in which the electronic control unit 50 disables the regenerative braking mode and increases the hydraulic braking force by an amount corresponding to the decrease in the regenerative braking force speaks. The period between time t ₃₄ and time t ₃₅ is a period in which the hydraulic braking force L ₅ is increased. Since the brake oil in the master cylinder 14 flows to a plurality of wheel brakes (not shown), the hydraulic pressure in the master cylinder 14 decreases.

In the braking system according to an embodiment of the present disclosure, the electric booster unit 20 is driven to increase the hydraulic braking force in the period between time t ₃₄ and time t ₃₅ , whereby the motor piston 28 moves from d ₃₂ to d ₃₃ and the master cylinder 14 is further compressed. As in 8C As shown, at time t ₃₅ the displacement of the actuating rod 12 does not change from r ₁₂ , only the displacement of the motor piston 28 changes. Since the actuating rod 12 continues to bear against the reaction disc 420 , the total pedaling force L ₁ is influenced by the pedaling force L ₂ of the elastomer 17 and the pedaling force L ₃ of the reaction disc 420 . However, the total pedaling force L ₁ does not change even though it is affected by the pedaling force L ₃ of the reaction disc 420 . This is described in detail below.

wobei in 8B P_rd1 sich auf den von der Reaktionsscheibe 420 auf den Betätigungsstab 12 ausgeübten Druck bezieht, in 8B sich A₁ auf die Kontaktfläche zwischen der Reaktionsscheibe 420 und dem Betätigungsstab 12 bezieht, in 8B sich K auf den Elastizitätskoeffizienten des Elastomers 17 bezieht, X₁ sich auf den Abstand bezieht, um den das Elastomer 17 zusammengedrückt wird in 8B, P_rd2 sich auf den Druck bezieht, der von der Reaktionsscheibe 420 auf die Betätigungsstange 12 in 8C ausgeübt wird, A₂ sich auf die Kontaktfläche zwischen der Reaktionsscheibe 420 und der Betätigungsstange 12 in 8C bezieht und X₂ sich auf den Abstand bezieht, um den das Elastomer 17 in 8C zusammengedrückt wird.If the driver in 8B pedal force felt with F ₁ and that of the driver in 8C pedal force felt is denoted by F ₂ , F ₁ and F ₂ satisfy Equation 1: $$\begin{array}{c}{\text{<figure-callout id="1" label="f" filenames="DE102022104252A1\_0010.png,DE102022104252A1\_0015.png" state="{{state}}">f</figure-callout>}}_1={\text{P}}_{\text{approx}1}{\text{<figure-callout id="1" label="A" filenames="DE102022104252A1\_0010.png,DE102022104252A1\_0015.png" state="{{state}}">A</figure-callout>}}_1+{\text{KX}}_1\\ {\text{<figure-callout id="2" label="f" filenames="DE102022104252A1\_0004.png,DE102022104252A1\_0017.png" state="{{state}}">f</figure-callout>}}_2={\text{P}}_{\text{approx}2}{\text{<figure-callout id="2" label="A" filenames="DE102022104252A1\_0004.png,DE102022104252A1\_0017.png" state="{{state}}">A</figure-callout>}}_2+{\text{<figure-callout id="2" label="KX" filenames="DE102022104252A1\_0004.png,DE102022104252A1\_0017.png" state="{{state}}">KX</figure-callout>}}_2\end{array}$$

where in 8B P _rd1 refers to the pressure exerted by the reaction disk 420 on the actuating rod 12, in 8B A ₁ refers to the contact area between the reaction disk 420 and the actuating rod 12, in 8B K relates to the coefficient of elasticity of the elastomer 17, X ₁ relates to the distance that the elastomer 17 is compressed in 8B , P _rd2 refers to the pressure exerted by the reaction disk 420 on the actuating rod 12 in 8C is exerted, A ₂ affects the contact surface between the reaction disc 420 and the actuating rod 12 in 8C and X ₂ relates to the distance that the elastomer 17 in 8C is compressed.

In the period between 8B and 8C the displacement of the actuating rod 12 remains at point r ₃₂ , ie X ₁ =X ₂ . Therefore, KX ₁ = KX ₂ .

In 8C the hydraulic braking force must be increased by an amount corresponding to the decrease in the regenerative braking force, and therefore the motor piston 28 is moved further forward toward the master cylinder 14. Motor piston 28 further compresses reaction disc 420 while actuator rod 12 displacement is maintained. As a result, the central part 423 of the reaction disc 420, which is made of an elastic material, protrudes further, and the reaction disc 420 has a higher pressure (P _rd1 < P _rd2 ).

However, even if the pressure exerted by the reaction disc 420 on the operating rod 12 varies, the middle part 423 of the reaction disc 420 protrudes 8C further out so that the contact area with the operating rod 12 becomes smaller. Therefore, A ₁ > A ₂ .

Although P _rd1 < P _rd2 , because ≈ P _rd1 A ₁ ≈ P _rd2 A ₂ because A ₁ > A ₂ . In this disclosure, the reaction disk 420 is made of an elastic material, and the amount of protrusion and the area of contact with the actuating rod 12 may vary with changes in the elasticity of the reaction disk 420. Reaction disc 420 may be designed such that P _rd1 A ₁ =P _rd2 A ₂ , thereby eliminating any difference between pedal forces F ₁ and F ₂ den, pedal feels as regenerative braking force decreases and hydraulic braking force increases.

9 12 is a graph for explaining a relationship among total pedal force, pedal force of an elastomer, pedal force of a reaction disk, regenerative braking force, and hydraulic braking force versus time if the amount of pedal effort increases while regenerative braking is disabled during braking when the electrical control unit performs regenerative braking and hydraulic braking. 10 FIG. 12 is a schematic diagram for explaining the operation at the starting point, time t ₄₄ and time t ₄₅ of FIG 9 .

10A shows the operation at the starting point of 9 , 10B shows the operation at the time of t ₄₄ 9 , and 10C shows the operation at time t ₄₅ from 9 . Here the operation of the braking system in the period between the starting point and time t ₄₄ in the in 9 11 is similar to the operation in the period between the start point and time t ₃₄ , so a description thereof is omitted.

At a specific point in time t ₄₄ , the electrical control unit 50 deactivates the regenerative braking mode and controls the electrical booster unit 20 in order to increase the hydraulic braking force L ₅ . In the time between time t ₄₄ and time t ₄₅ , regenerative braking force L ₄ decreases and hydraulic braking force L ₅ increases. As in 9 shown, the driver increases during this period, the pedal force, so that the required hydraulic braking force L ₅ is greater than the maximum available braking force L ₄ .

The amount of increase in hydraulic braking force L ₅ between time t ₄₄ and time t ₄₅ shown in FIG 9 is larger than in the in 7 shown period between time t ₃₄ and time t ₃₅ .

Nevertheless, the brake system according to an embodiment of the present disclosure prevents the driver from having an unnatural pedal feel.

As in 10B and 10C As shown, the displacement of the operating rod 12 moves from r ₄₂ to r ₄₃ as the driver increases the amount of pedal effort. In addition, when the electric booster unit 20 is driven, the motor piston 28 compresses the disk unit 42, causing the displacement of the disk unit 42 to move from r ₄₂ to r ₄₃ and compressing the master cylinder 14, thereby increasing the hydraulic pressure. While operating in 10B and 10C For example, the actuating rod 12 continues to abut the central portion 423 of the reaction disc 420, but there is little change in pedaling force felt by the driver, as explained with reference to Equation 1. Accordingly, despite a change in the hydraulic pressure in the master cylinder 14, the driver does not have an unnatural pedal feeling.

11 1 is a flow diagram of a method for controlling a braking system according to an embodiment of the present disclosure. This in 11 The flow chart presented is a description of some of numerous braking methods, and the electronic control unit 50 does not necessarily include the algorithm of FIG 11 , but can include a variety of braking algorithms including this one. 11 14 is a flowchart drawn on the assumption that only the regenerative braking unit is driven, and apart from that, the electric control unit 50 may include methods for braking by driving the hydraulic braking unit alone.

The electric control unit 50 receives a brake pedal signal (S10). That is, the electronic control unit 50 receives a signal from the brake pedal 11 to check whether the driver operates the pedal 11 or not. If the electronic control unit 50 does not receive a brake pedal signal, it is determined that there is no braking situation and the control method of FIG 11 continued.

When the electronic control unit 50 receives a brake pedal signal, it calculates the total braking force required (S20). The total required braking force is determined based on the amount of effort exerted by the driver on the pedal 11, and the electronic control unit 50 can additionally determine the required total braking force if it is equipped with an autonomous driving function. When the driver presses the pedal 11, the electronic control unit 50 calculates the total braking force required to brake the vehicle based on the effort on the pedal 11 measured by a pedal travel sensor (not shown).

The electric control unit 50 calculates the required regenerative braking force based on the total required braking force (S20). After calculating the required regenerative braking force, the electric control unit 50 drives the regenerative braking unit (not shown) based on the calculated required regenerative braking force (S40).

While the regenerative braking unit (not shown) is being driven, the electric control unit 50 determines whether or not to end the regenerative braking (S50). The electronic control unit 50 can determine whether or not to stop regenerative braking by itself, or it can determine whether or not to stop regenerative braking by using a regenerative braking stop signal received from the outside.

If it is determined that the regenerative braking has ended, the electronic control unit calculates the required hydraulic braking force corresponding to the termination of the regenerative braking (S60). Once the electronic control unit 50 deactivates the regenerative braking mode, the regenerative braking force is reduced. The electronic control unit 50 detects the amount of decrease in regenerative braking force and calculates the hydraulic braking force required to compensate for the detected decrease in braking force.

The electric control unit 50 calculates a required displacement of the motor piston 28 according to the required hydraulic braking force (S70). The required displacement of the motor piston 28 is determined based on the displacement of the motor piston 28 at a time when the electronic control unit 50 terminates regenerative braking.

The electric control unit 50 drives the electric booster unit 20 so that the motor piston 28 moves to the required displacement (S80). The electrical control unit 50 moves the motor piston 29 toward the master cylinder 14 so that the electrical booster unit 20 is driven to compress the reaction disk 420. At this time, the reaction disk 420 may be formed of an elastic material, and the motor piston 28 may abut an outer periphery of the reaction disk 420 . When the motor piston 28 compresses the reaction disk 420 , the middle portion 423 of the reaction disk 420 may protrude toward the actuator rod 12 . The protruding reaction disc 420 exerts a reaction force on the operating rod 12 when abutting against the operating rod 12 . This reaction force is part of the pedal force felt by the driver. In this disclosure, as explained with reference to Equation 1 above, even if the reaction disc 420 and the operating rod 12 collide, the driver does not have unnatural pedal feel in the period in which the regenerative braking force decreases and the hydraulic braking force increases.

After step S80, the algorithm of this disclosure is complete.

A brake system according to a second embodiment of the present disclosure and a method for controlling the brake system will be described below.

It should be noted that those in the 12 until 14 and 16 The conceptual diagrams of a brake system 1b illustrated in the present disclosure are briefly presented in the present disclosure to facilitate understanding of the operational process of the brake system 1b, and may differ from the actual detailed form of the brake system 1b.

Configuration of the braking system

12 14 is a conceptual diagram showing the initial state of a brake system according to a second embodiment of the present disclosure.

Referring to 12 A brake system 1b according to a second embodiment of the present disclosure includes a pedal main unit 10b, an electric booster unit 20b, a case 30b, a pedal force generating unit 40b, and an electric control unit 50b in whole or in part.

When a driver operates a pedal 11b, the pedal main unit 10b transmits the operation to the master cylinder 14b. The pedal main unit 10b consists entirely or partially of an operating rod 12b, a push rod 13b, a master cylinder 14b and a return spring 15b.

The pedal 11b is a part operated by a driver to slow down or stop a vehicle. When a driver depresses the pedal 11b and a first end of the operating rod 12b is pressed with a predetermined pressure or more, a second end of the operating rod 12b pushes a reaction disc 32b. In this case, the stroke of the pedal 11b is detected by a pedal travel sensor (not shown) provided separately.

The operating rod 12b is a medium that transmits a driver's pedaling effort to the reaction disc 420b. The first end of the operating rod 12b is connected to the pedal 11b. The pedal force F _RD transmitted to the reaction disc 420b is transmitted to the master cylinder 14b via the operating rod 12b. In the initial state in which the pedal 11b begins to operate, the second end of the operating rod 12b is spaced from the reaction disk 420b. When the pedal 11b is depressed, the second end of the operating rod 12b is moved forward toward the reaction disk 420b.

The push rod 13b is at least partially inserted into the master cylinder 14b. The push rod 13b reciprocates in the longitudinal direction of the master cylinder 14b in the master cylinder 14b and can push brake fluid stored in the master cylinder 14b as it moves forward.

The master cylinder 14b is configured to hold brake fluid therein. Hydraulic pressure used for braking is generated when the brake fluid in the master cylinder 14b is pushed. The generated hydraulic pressure is transmitted to a plurality of wheel brake units (not shown).

The return spring/return spring 15b is disposed in the master cylinder 14b and is compressed or expanded by reciprocation of the push rod 13b. The return spring 15b can preferably be a helical spring. However, the present disclosure is not necessarily limited thereto, and the return spring may be a disc spring or an elastomer such as a rubber. e.g. rubber. Further, although not illustrated in the present disclosure, the return spring 15b may be disposed in the housing of the electric booster unit 20b. The return spring 15b can be arranged in the master cylinder 14b or in the electric booster unit 20b to form a part of the force transmitted from the operating rod 12b and the electric booster unit 20b.

The electric boosting unit 20b is configured to boost a driver's pedaling force. The electric booster unit 20b includes, in whole or in part, a motor 22b, a gearbox 24b, a propeller shaft 26b, and a motor piston 28b.

The motor 22b is configured to rotate forward or reverse in response to a signal from the controller 50b.

The transmission device 24b is configured to transmit the torque of the motor 22b to the screw shaft 26b. The transmission device 24b consists entirely or partially of a first gear 240b, a second gear 242b and a third gear 244b.

The first gear 240b mainly receives the torque transmitted from the motor 22b and transmits it to the second gear 242b. The second gear 242b transfers the torque received from the first gear 240b to the third gear 244b. The third gear 242b transmits the torque received from the second gear 242b to the screw shaft 26b. Depending on the ratio of the number of teeth of the first gear 240b and the third gear 244b, the rotational speed can increase or decrease in a certain ratio while the torque is transmitted from the first gear 240b to the third gear 244b.

The screw shaft 26b is configured to convert the torque transmitted by the gear device 24b into rectilinear motion. The screw shaft 26b consists entirely or partially of a first shaft 260b and a second shaft 262b.

The first shaft 260b is rotated in a state limited by the third gear 244b. The second shaft 262b is configured to convert rotational motion of the first shaft 260b into linear motion. Preferably, the first shaft 260b may consist of a pinion, a second shaft 262b and a rack. A first end of the second shaft 262b is connected to the motor piston 28b. When the motor 22b is driven, the second shaft 262b moves the reaction disc 420b forward or backward in the opposite direction.

The motor piston 28b is reciprocated in the longitudinal direction of the master cylinder 14b by a power transmitted through a combination of the gear device 24b and the screw shaft 26b. The motor piston 28b is arranged so that a first end is pushed by the second shaft 262b and a second end by the reaction disc 420b.

The motor piston 28b is close to the first shaft 260b when the pedal 11b is not being actuated, i. H. when there is no brake request signal. Hereinafter, the position of the motor piston 28b in the state described above is referred to as “adjustment position”.

The housing 30b is configured to enclose at least a portion of the pedal unit 10b, at least a portion of the electric booster unit 20b, and at least a portion of the pedal force generating unit 40b. The housing 30b includes a spring mount 32b.

The spring mount 32b is fixed to the housing 30b, and at least a portion of a pedal spring assembly 44b is attached to a surface of the spring mount 32b. When a rider pedals and the pedal spring unit 44b is pressed, the spring bracket 32b supports the pedal spring 44b.

When a driver operates the pedal 11b, the pedaling force generating unit 40b provides pedaling force to the driver. The pedal force generating unit 40b consists entirely or partially of a disk unit 42b and a pedal spring unit 44b.

The disc assembly 42b is arranged to be pushed by one or more of the actuator rod 12b and motor piston 28b. A reaction force generated by the disk unit 42b against the pedaling force is transmitted to the push rod 13b. The push rod 13b pushes the brake oil stored in the master cylinder 14b, and at least part of the pressed disk oil is transmitted to the plurality of wheel brake units, whereby a hydraulic braking force F _byd can be generated.

The disk unit 42b includes a reaction disk 420b and a reaction disk container 422b.

The reaction disc 420b is arranged to be pushed by the operating rod 12b. When a first end of the operating rod 12b is pushed by a force applied by a driver to operate the pedal 11b, a second end thereof pushes the reaction disk 420b.

In addition, reaction disc 420b is arranged to be driven by motor piston 28b is pressed. Meanwhile, the reaction disk 420b and the motor piston 28b are also in the initial state 12 in contact with each other. However, when no brake demand signal is generated by controller 50b, motor piston 28b may be spaced from reaction disk 420b.

When the pedal 11b is pressed, one end of the operating rod 12b moves forward toward the reaction disk 420b, whereby they come into contact with each other as shown in FIG 14B shown. If the pedal 11b, as in 14B 1 is pushed further, the outer periphery of the reaction disc 420b is pushed by the motor piston 28b and the central part of the reaction disc 420b is pushed by the operating rod 12b. For this purpose, the end surface of the motor piston 28b can be formed in a substantially annular shape and the actuating rod 12b can be passed through an open central portion of the motor piston 28b. In this case, the operating rod 12b and the reaction disk 420b are arranged coaxially. However, the present disclosure is not necessarily limited thereto, and the outer periphery of the reaction disk 420b may be pressed by the operating rod 12b and the center portion of the reaction disk 420b may be pressed by the motor piston 28b. In this case too, it is advantageous for the operating rod 12b and the reaction disk 420b to be arranged coaxially.

The reaction disk 420b is made of a compressible material. For example, at least a portion of reaction disk 420b may be made of rubber. When the reaction disk 420b is compressed by the operating rod 12b or the motor piston 28b, the reaction force generated by the compressive force is transmitted to the rider through the operating rod 12b and accounts for part of the pedaling force felt by the rider. Hereinafter, the pedaling force generated when the reaction disk 420b is compressed by an external force is denoted by F _RD .

The reaction disk container 422b is configured to accommodate at least a portion of the reaction disk 420b in an accommodating space formed therein. When a first side of reaction disc case 422b is pushed by one or more of actuating rod 12b and motor piston 28b, a second side of reaction disc case 422b pushes on push rod 13b.

The pedal spring unit 44b is connected to the actuating rod 12b on a first side and to the spring carrier 32b on a second side. When the relative distance between the pedal 11b and the spring bracket 32b increases or decreases, the pedal spring unit 44b generates a tensile force or a compressive force. The reaction force generated when the pedal spring unit 44b is compressed is transmitted to the rider through the operating rod 12b and constitutes part of the pedaling force felt by the rider. Hereinafter, the pedaling force generated when the pedal spring unit 44b is compressed by an external force is denoted by F _spring .

The pedal spring unit 44b includes a spring 449b and a damper 442b. Although the spring 440b and the damper 442b are connected in series in the present disclosure, the present disclosure is not limited thereto, and the spring 440b and the damper 442b may be connected in parallel.

The total pedaling force F _pedal transmitted to the driver can be expressed as the sum of the pedaling force F _RD generated by a reaction force against a pressing force of the disk unit 42b and the pedaling force F _spring generated by a reaction force against a pressing force of the pedal spring unit 44b is generated can be determined.

The control unit 50b generates a braking request signal based on a pedal stroke s _received from a pedal travel sensor (not shown). The pedal request signal is an electrical signal that causes at least some of the plurality of wheel brake assemblies (not shown) to generate a braking force.

The control unit 50b calculates a total required braking force F _total for braking a vehicle based on a pedal stroke s. Further, the control unit 50b determines whether to perform regenerative braking and controls the electric brake booster unit 20b differently depending on whether to perform regenerative braking. The operation of the braking system 1b when a regenerative braking mode is started will be described with reference to FIG 14 until 15 described, and the operation of the brake system 1b when a hydraulic braking mode is started will be described with reference to FIG 16 until 17 described.

dead stroke condition

13 14 is a conceptual diagram showing a dead stroke state of the brake system according to the second embodiment of the present disclosure. shows in detail 13 a state in which a driver starts to operate the pedal 11b, ie, a state in which braking is applied request signal is generated by the control unit 50b. 13 shows a state in which a pedal stroke s satisfies the condition s<s ₁ .

If a state of 12 to 13 , that is, when s < s ₁ and s increases, one end of the operating rod 12b does not come into contact with the reaction disc 420b even if the operating rod 12b moves forward. Accordingly, the pedal force F _RD generated by the reaction disk 420b is not transmitted to the driver. In this case, the distance between the spring bracket 32b and the operating rod 12b decreases, and at least part of the pedal spring 44b is compressed. F _spring generated by a reaction force against the pressing force of the pedal spring 44b is transmitted to the driver and is F _pedal . That is, a relationship F _spring = F _pedal is satisfied.

Even if the pedal 11b is in the states in 12 until 13 is operated, no regenerative braking force and no hydraulic braking force is applied to the vehicle. That is, the brake system 1b is in the in the 12 until 13 states shown in a dead stroke phase.

Regenerative braking mode

The regenerative braking mode of the braking system according to the second embodiment of the present disclosure includes a first regenerative braking mode and a second regenerative braking mode.

When braking in the first regenerative braking mode, the braking system 1b performs braking using only the regenerative braking force present in the vehicle. That is, the entire requested braking force F _totat is also satisfied only by a regenerative braking force F _reg generated by a regenerative braking unit (not shown). When braking in the second regenerative braking mode, the braking system 1b brakes by both regenerative braking and hydraulic braking. That is, the total requested braking force F _total is the sum of the regenerative braking force F _reg and the hydraulic braking force F _hyd . In the present disclosure, the operation of the braking system in the first regenerative braking mode is discussed with reference to FIG 14A and the operation of the braking system 1b in the second regenerative braking mode with reference to FIG 14b until 14c described.

14A 14 is a conceptual diagram showing a first state of the regenerative braking mode of the braking system according to the second embodiment of the present disclosure.

In detail, a state of s ₁ ≤ s < s ₂ is in 14A shown If the pedal travel sensor detects the condition s = s ₁ , the control unit 50b controls the regenerative braking unit (not shown) to perform regenerative braking. When s ₁ ≤ s < s ₂ and increases, the motor piston 28b moves forward and the reaction disk 420b is further compressed from the previous state. However, since the first end of the operating rod 12b and the reaction disk 420b are not in contact with each other, the pedal force F _RD generated by the reaction disk 420b is not transmitted to the driver. Accordingly, the total pedal force F _pedal is determined only as the pedal force F _spring generated by the pedal spring 44b. This means that the brake system 1b works in the F _pedal =F _spring first regenerative braking mode.

Since the disk unit 42b is disposed in an area where hydraulic pressure is not generated in the first regenerative braking mode, the disk unit 42b does not transmit power to the brake oil stored in the master cylinder 14b. Accordingly, the total requested braking force F _total is only determined by the regenerative braking force F _reg . That is, the braking system 1b satisfies F _total =F _reg in the first regenerative braking mode.

14b and 14c 10 are conceptual diagrams showing the state after the start of a second regenerative braking mode of the braking system according to the second embodiment of the present disclosure. In detail, a state of s = s ₂ in 14B and a condition of s > s ₂ in 14C shown. When s=s ₂ the first end of the operating rod 12b and the reaction disk 420b are in contact with each other. Accordingly, F _RD , which is a reaction force against a pressing force generated when the reaction disk 420b is pressed, can be transmitted to the driver. Meanwhile, the displacement of motor piston 28b calculated by controller 50b to produce a corresponding pedal force F _pedal is referred to as first displacement d ₁ .

Further, at least part of the reaction disk reservoir 422b is inserted into the master cylinder 14b from the time s=s ₂ , ie, when the disk unit 42b pushes the brake oil in the master cylinder 14b, hydraulic braking force F _hyd can be generated.

in the in 14b until 14c shown state s ≥ s ₂ , the total pedal force F _pedal than The sum of the pedal force F _RD generated by the disk unit 42b and the pedal force F _spring generated by the pedal spring unit 44b is determined. That is, the braking system 1b satisfies F _pedal =F _spring +F _RD in the second regenerative braking mode.

Further, in a state of s ≥ s ₂ , the total requested braking force is determined as the sum of the hydraulic braking force F _byd and the regenerative braking force F _reg generated when the disk unit 42b presses the inside of the master cylinder 14b. That is, the brake system 1b satisfies F _total =F _reg +F _hyd in the second regenerative braking mode.

In the second regenerative braking mode, displacement d of motor piston 28b is the sum of first displacement d ₁ to produce F _RD and second displacement d ₂ to produce F _byd .

15 12 is a graph showing the relationship between a pedal stroke and the pedal force in each period in a regenerative braking mode of the brake system according to the second embodiment of the present disclosure. Changes in the pedal force and the pressure of the brake system 1b in the in the 12 until 14c States shown are based on an increase in pedal travel s with reference to 15 described.

The operating state of the braking system 1b for s<s ₁ corresponds to that in 13 shown operating status. When the pedal 11b is depressed, the operating rod 12b is moved forward toward the reaction disc 420b. In this case, as in 13 shown, the first end of the actuating rod 12b shifted so that the total pedal force F _pedal is not affected. For example, the first end of actuation rod 12b may be spaced from reaction disk 420b. Accordingly, the force constituting the total pedal force F _fedal provided by a driver is only the pedal force F _spring generated by the pedal spring unit 44b. Accordingly, F _pedal =F _spring , the brake system 1b according to the present disclosure satisfies the condition when s<s ₁ . The pedal force F _spring generated by the pedal spring unit 44b can increase substantially linearly in relation to the compressive force of the pedal spring unit 44b.

In the meantime, this state is a dead stroke period in which a regenerative braking force F _reg and a hydraulic braking force F _byd are not generated regardless of the pedaling force by operating the pedal 11b.

The operating state of the brake system 1b for s ₁ ≦s<s ₂ corresponds to that in 14A shown operating status. When the pedal 11b is depressed, the motor piston 28b moves relative to that in FIG 13 state shown further forward and presses on the reaction disk 420b. However, since the first end of the actuating rod 12b is spaced from the reaction disk 420b, the F _pedal forming force is only F _spring . Accordingly, when s ₁ ≤ s < s ₂ , the braking system 1b according to the present disclosure satisfies F _pedal = F _spring in regenerative braking mode. The pedal force F _spring generated by the pedal spring unit 44b can increase substantially linearly in relation to the compressive force of the pedal spring unit 44b.

Meanwhile, in this state, a regenerative braking force F _reg is generated. Accordingly, when s ₁ ≤ s < s ₂ , the braking system 1b according to the present disclosure satisfies F _total = F _reg in the regenerative braking mode.

The operating state of the braking system 1b for s=s ₂ corresponds to that in 14B shown operating status. The motor piston 28b moves forward, and the central part of the reaction disc 420b, the outer periphery of which is further depressed, further protrudes. In addition, the operating rod 12b also moves forward. Accordingly, at the time s=s ₂ , the first end of the operating rod 12b comes into contact with the reaction disk 420b. Accordingly, the pedal force F _RD generated by the reaction disc 420b can be transmitted to the driver. Accordingly, when s=s ₂ , the braking system 1b according to the present disclosure satisfies F _pedal =F _spring +F _RD in the regenerative braking mode.

In this state, the disk unit 42b starts to press the brake oil stored in the master cylinder 14b, whereby a hydraulic braking force F _hyd is generated. Accordingly, when s=s ₂ , the braking system 1b according to the present disclosure satisfies F _total =F _reg +F _hyd in the regenerative braking mode.

The operating state of the braking system 1b for s > s ₂ corresponds to that in 14C shown operating status. When s > s ₂ , the braking system 1b according to the present disclosure satisfies F _pedal = F _spring + F _RD in the regenerative braking mode. Meanwhile, the pedaling force generated by a reaction force against the urging force of the return spring 15b disposed in the master cylinder 14b is not considered in the present disclosure.

The force of the operating rod 12b pressing the reaction disk 420b and the force of the motor piston 28b pressing the reaction disk 420b are applied to that in the master cylinder 14b transfer stored brake oil. At least a portion of the force transmitted to the master cylinder 14b creates a hydraulic braking force F _byd . Accordingly, when s > s ₂ , the braking system 1b according to the present disclosure satisfies F _total = F _reg + F _hyd in the regenerative braking mode.

Hydraulic braking mode

The braking system 1b according to the second embodiment of the present disclosure performs braking without using a regenerative braking unit provided in a vehicle when braking in the hydraulic braking mode. Accordingly, the entire requested braking force F _total is only met by the hydraulic braking force F _hyd . Accordingly, the braking system 1b meets the requirements during F _total ≤ F _hyd of the entire period of the hydraulic braking mode.

The hydraulic braking mode of the braking system according to the second embodiment of the present disclosure includes a first hydraulic braking mode and a second hydraulic braking mode. In the first hydraulic braking mode, the entire pedal force F _pedal is applied only by the pedal force F _spring generated by the pedal spring unit 44b. In the second hydraulic braking mode, the total pedal force F _pedal is only achieved by the sum of F _spring and the pedal force F _RD generated by the disc unit 42b. In the present disclosure, operation of the braking system in the first hydraulic braking mode is discussed with reference to FIG 16A and the operation of the braking system 1b in the second hydraulic braking mode with reference to FIG 16b until 16c described.

Meanwhile, the operating state of the braking system 1b for s<s ₃ may be the same as or identical to the operating state of the braking system 1b for s<s ₁ in the regenerative braking mode, so in this case, the description in FIGS 12 and 13 is referenced.

16A 14 is a conceptual diagram showing a first state of the hydraulic braking mode of the braking system according to the second embodiment of the present disclosure. In detail is in 16A a state s ₃ ≤ s < s ₄ is shown. When s < s ₃ is detected by the pedal travel sensor, the control unit 50b controls the brake system 1b to perform hydraulic braking using the pedal main unit 10b. As s ₃ ≤ s < s ₄ and s increases, motor piston 28b moves forward and reaction disc 420b is further compressed from the previous condition. However, since the first end of the operating rod 12b and the reaction disk 420b are not in contact with each other, the pedaling force F _RD generated by the reaction disk 420b is not transmitted to the driver. Accordingly, the total pedal force F _pedal is determined only as the pedal force F _spring generated by the pedal spring 44b. This means that the braking system 1b satisfies F _pedal = F _spring in the first hydraulic braking mode. In the meantime, the pedaling force F _spring generated by the pedal spring unit 44b may increase substantially linearly in proportion to the pushing force of the pedal spring unit 44b.

16b and 16c 12 are conceptual diagrams showing the state after starting a second hydraulic braking mode of the brake system according to the second embodiment of the present disclosure. In detail, a state of s = s ₄ in 16B and a condition of s > s ₄ in 16C shown. When s=s ₄ the first end of the operating rod 12b and the reaction disc 420b are in contact with each other. Accordingly, F _RD , which is a reaction force against a pressing force generated when the reaction disk 420b is pressed, can be transmitted to the driver. That is, the brake system 1b according to the present disclosure satisfies the requirements F _pedal = F _spring + F _RD in the second hydraulic braking mode. Meanwhile, the pedaling force F _spring generated by the pedal spring unit 44b can increase substantially linearly in proportion to the pressing force of the pedal spring unit 44b.

17 14 is a graph showing the relationship between a pedal stroke and a pedal force in each period in a hydraulic braking mode of the brake system according to the second embodiment of the present disclosure. Changes in the pedal force and the pressure of the brake system 1b in the in 16a until 16c States shown are based on an increase in pedal travel s _b with reference to 17 described.

The operating state of the brake system 1b for s<s ₃ corresponds to that in 12 until 13 shown operating status. For this period, reference is made to the description of s < s ₁ for regenerative braking.

The operating state of the braking system 1b for s ₃ ≦s<s ₄ corresponds to that in 16A shown operating status. When the pedal 11b is depressed, the motor piston 28b moves relative to that in FIG 13 state shown further forward and presses on the reaction disk 420b. However, since the first end of the actuating rod 12b is spaced from the reaction disc 420b, the force F _pedal is only F _spring . Accordingly, if s ₃ ≤ s < s ₄ satisfies that Braking system 1b according to the present disclosure F _pedal = F _spring in the hydraulic braking mode the requirements. The pedal force F _spring generated by the pedal spring unit 44b can increase substantially linearly in relation to the compressive force of the pedal spring unit 44b.

The operating state of the braking system 1b s = s ₄ corresponds to that in 16B shown operating status. The motor piston 28b moves forward, and the central part of the reaction disc 420b, the outer periphery of which is further depressed, further protrudes. In addition, the operating rod 12b also moves forward. Accordingly, at the time s=s ₄ , the first end of the operating rod 12b comes into contact with the reaction disc 420b. Accordingly, the pedal force F _RD generated by the reaction disc 420b can be transmitted to the driver. Accordingly, when s=s ₂ , the braking system 1b according to the present disclosure satisfies F _pedal =F _spring +F _RD in the hydraulic braking mode. The pedal force F _spring generated by the pedal spring unit 44b can increase substantially linearly in relation to the compressive force of the pedal spring unit 44b.

The operating state of the braking system 1b for s > s ₄ corresponds to that in 16C shown operating status. When s > s ₄ , the braking system 1b according to the present disclosure satisfies F _pedal = F _spring + F _RD in the regenerative braking mode. Meanwhile, the pedaling force generated by a reaction force against the urging force of the return spring 15b arranged in the master cylinder 14b is not considered in the present disclosure.

Method for controlling a braking system

Although the in the 18 until 19 processes shown in the present disclosure are performed sequentially in a time series, it should be noted that some or all of the processes may be performed simultaneously regardless of the order.

18 12 is a flowchart showing a method for controlling the brake system according to the second embodiment of the present disclosure.

Referring to 18 When a driver operates the pedal 11b, a brake pedal signal is input to the control unit 50b (S700b).

When the brake pedal signal is input, the control unit 50b calculates a total required braking force F _total based on a stroke value detected by the pedal travel sensor PTS (S710b).

After that, the control unit 50b determines whether the vehicle should be braked in the regenerative braking mode (S720b). In this case, the braking force generated by the regenerative braking unit is defined as regenerative braking force F _reg .

When the control unit 50b determines to operate the regenerative braking unit, the control unit 50b brakes the vehicle by starting the regenerative braking mode (S740b). When the control unit 50b determines that the regenerative braking unit should not be driven, it brakes the vehicle by starting the hydraulic braking mode (S750b).

When the regenerative braking mode or the hydraulic braking mode is started, the control unit 50b calculates the motor piston displacement d _b at which a total requested braking force F _total and the total pedaling force F _pedal can be generated (S760b).

On the basis of the calculated path d, the control unit 50b controls the electric booster unit 20b and thus regulates the brake system 1b in such a way that the motor piston can move the desired d (S770b).

19 12 is a flowchart showing a control procedure in the second regenerative braking mode state of the braking system according to the second embodiment of the present disclosure. A detailed control method of the electric booster unit 20b in the second regenerative braking mode is described with reference to FIG 19 described. Meanwhile, the content of S810b is in 19 the same as the process of S710b in 18 , so that it will not be described in detail.

In the second regenerative braking mode, the control unit 50b calculates a requested regenerative braking force F _reg (S820b).

In this case, the controller 50b calculates the first displacement d ₁ of the motor piston 28b so that the corresponding pedal force F _pedal is transmitted to the driver based on the detected pedal travel s (S830b). Although reference point d ₁ is described and illustrated in the present disclosure as an end of motor piston 28b in a set position (see FIG 14B) , the reference point is not necessarily limited to this. For example, d ₁ may be a distance from a first wave 260b, which is a fixed component.

The control unit 50b calculates an appropriate hydraulic braking force F _hyd based on the detected pedal stroke s. In this case, F _hyd = F _total - F _reg is used for the calculation (S840b).

The control unit 50b calculates a second displacement d ₂ of the motor piston 28b so that an appropriate hydraulic braking force F _hyd is generated based on the detected pedal travel s _b (S850b).

The control unit 50b uses d ₁ and d ₂ to calculate the corresponding displacement d of the engine piston. In this case the condition d=d ₁ +d ₂ is fulfilled. Thereafter, the control unit derives the electric booster unit 20b using the calculated d so that the displacement of the engine piston _is the calculated d (S870b).

A brake system according to a third embodiment of the present disclosure and a method for controlling the brake system will be described below.

20 14 is a cross-sectional view of a brake system according to a third embodiment of the present disclosure.

In 20 Illustrated is a brake system 1c according to a third embodiment of the present disclosure, including in whole or in part a pedal main unit 10c, an electric booster unit 20c, a housing 30c, a disc unit 42c, and an electric control unit 50c.

The pedal main unit 10c includes, in whole or in part, a pedal 11c, a rod assembly 60c, a push rod 13c, a master cylinder 14c, and a return spring 15c.

The pedal 11c is a part that is depressed by a driver to slow down or stop a vehicle. When a driver depresses the pedal 11c and a first end of the operating rod 12c is pressed with a predetermined pressure or more, the operating rod 12b moves toward a reaction disc 420c. In this case, the stroke of the pedal 11c can be detected by a pedal stroke sensor (not shown) provided separately. The first end of the actuating rod 12c may be placed in contact with the center portion of the reaction disk 420c.

The rod assembly 60c includes an actuating rod 12c, an elastomer 17c and an elastomeric connector 16c.

The operating rod 12c is a medium that transmits a driver's pedaling effort to the reaction disc 420c. The first end of the operating rod 12c is connected to the pedal 11c. Actuating rod 12c may push master cylinder 14c by pushing reaction disk 420c toward master cylinder 14c in cooperation with motor piston 28c. In the initial state where the pedal 11c begins to be depressed, the second end of the operating rod 12c may be spaced from the reaction disc 420c. When the pedal 11c is depressed, the second end of the operating rod 12b is moved forward toward the reaction disc 420c.

A first end of the elastomer 17c is located in contact with the operating rod 12c and a second end thereof is located in contact with the elastomeric port 16c. The elastomer connecting piece 16c can, as in 20 shown formed on a first surface of a screw shaft, but may also be formed on a portion of a second surface where the motor piston 28c contacts the reaction disk 420c as in FIG 23 shown. Further, the elastomeric link 16c may be formed in a space where it can move with a straight movement of the motor piston 28c.

The elastomer 17c generates an elastic force in response to movement of the operating rod 12c. When a driver actuates the pedal 11c, the actuating rod 12c compresses the elastomer 17c while moving towards the reaction disc 420c. The compressed elastomer 17c generates a reaction force which is an elastic force and thereby exerts a pedaling force on the rider. Since the second end of the elastomer 17c is in contact with the elastomeric port 16c, the elastomer 17c is only affected by the displacement of the operating rod 12c and the displacement of the motor piston 28c. Even when the operating rod 12c is not in contact with the reaction disk 420c and no reaction force is generated from the reaction disk 420c, the rider can feel the pedaling force by the reaction force of the elastomer 17c.

The elastomer 17c can be a spring or a combination of a spring 171c and a damper 172c. Although a spring 171c and a damper 172c are connected in series in the present disclosure, the present disclosure is not limited thereto, and the spring 171c and the damper 172c may be connected in parallel.

The push rod 13c is at least partially inserted into the master cylinder 14c. the pressure Rod 13c reciprocates in the master cylinder 14c in the longitudinal direction of the master cylinder 14c and can press brake fluid stored in the master cylinder 14c as it moves forward.

The master cylinder 14c is configured to hold brake fluid therein. Hydraulic pressure used for braking is generated when the brake fluid in the master cylinder 14c is pressed. The generated hydraulic pressure is transmitted to a plurality of wheel brakes (not shown).

The return spring 15c is disposed in the master cylinder 14c and is compressed or expanded by the reciprocating movement of the push rod 13c. The return spring 15c may preferably be a coil spring. However, the present disclosure is not necessarily limited thereto, and the return spring may be a disc spring or an elastomer such as a rubber. e.g. rubber. Further, although not illustrated in the present disclosure, the return spring 15c may be disposed in the housing of the electric booster unit 20c. The return spring 15c may be arranged in the master cylinder 14c or in the electric booster unit 20c to be pushed by a part of the force transmitted by one or more of the actuating rod 12c and the electric booster unit 20c.

The electric boosting unit 20c is configured to boost a driver's pedaling force. The electric booster 20c includes in whole or in part a motor 22c, a gearbox 24c, a propeller shaft 26c and a motor piston 28c.

The motor 22c is configured to rotate forward or reverse about the axis of the motor 22c in response to a signal from the controller 50c.

The transmission device 24c is configured to transmit the torque of the motor 22c to the propeller shaft 26c. The transmission device 24c consists entirely or partially of a first gear 240c, a second gear 242c and a third gear 244c.

The first gear 240c mainly receives the torque transmitted from the motor 22c and transmits it to the second gear 242c. The second gear 242c transfers the torque received from the first gear 240c to the third gear 244c. The third gear 242c transmits the torque received from the second gear 242c to the screw shaft 26c. Depending on the ratio of the number of teeth of the first gear 240c and the third gear 244c, the rotational speed can increase or decrease in a predetermined ratio while the torque is transmitted from the first gear 240c to the third gear 244c.

The screw shaft 26c is configured to convert the torque transmitted by the gear device 24c into linear motion. The screw shaft 26c consists in whole or in part of a first shaft 260c and a second shaft 262c.

The first shaft 260c is rotated in a state limited by the third gear 244c. The second shaft 262c is configured to convert rotational motion of the first shaft 260c into linear motion. Preferably, the first shaft 260c may consist of a pinion, a second shaft 262c and a rack. A first end of the second shaft 262c is connected to the motor piston 28c. When the motor 22c is driven, the second shaft 262c moves the reaction disc 420c forward or backward in the opposite direction.

The motor piston 28c is reciprocated in the longitudinal direction of the master cylinder 14c by a power transmitted through a combination of the gear device 24c and the screw shaft 26c. Motor piston 28c is arranged so that a first end is pushed by second shaft 262c and a second end pushes reaction disk 420c.

The motor piston 28c is near the first shaft 260c when the pedal 11c is not being actuated, i. H. when there is no brake request signal.

Housing 30c is configured to enclose at least a portion of pedal assembly 10c, at least a portion of electrical amplifier assembly 20c, and at least a portion of pulley assembly 42c.

When the control unit 50c performs hydraulic braking, the disk assembly 42c pushes on the master cylinder 14c, applying hydraulic pressure to the plurality of wheel brakes (not shown). The disk assembly 42c includes a reaction disk 420c and a reaction disk container 422c.

The reaction disk 420c is arranged to be pushed by one or more of the actuating rod 12c and motor piston 28c. The reaction disk 420c and motor piston 28c are in 20 of the present disclosure in contact with each other. But when If no brake demand signal is generated by controller 50c, motor piston 28b may be spaced from reaction disk 420c.

The reaction disk 420c may be arranged such that the outer periphery of the reaction disk 420c, i. H. the outer edge being pushed by the motor piston 28c and the central part of the reaction disk 420c by the actuating rod 12c. To this end, the end surface of the motor piston 28c may be formed into a substantially annular shape, and the operating rod 12c may be passed through a hollow portion formed in the center of the motor piston 28c. In this case, the operating rod 12c and the reaction disc 420c are arranged coaxially. Meanwhile, the present disclosure is not limited thereto, and other braking systems are included in the present disclosure as long as the braking systems have a device that can press the reaction disk 420c when the pedal 11c is pressed and the motor 22c is driven.

The reaction disk 420c is made of a compressible elastic material. For example, at least a portion of reaction disk 420c may be made of rubber. When the reaction disk 420c is pushed by the operating rod 12c or the motor piston 28c, the reaction force generated by the pushing force is transmitted to the rider through the operating rod 12c and forms part of the pedaling force felt by the rider.

The reaction disk container 422c is configured to receive at least a portion of the reaction disk 420c in a receiving space formed therein. When a first side of reaction disk case 422c is pushed by actuating rod 12c or motor piston 28c, a second side of reaction disk case 422c pushes push rod 13c.

The total pedal force provided to a driver can be determined as the sum of the pedal force generated by a reaction force against the pressing force of the reaction disk 420c and the pedal force generated by a reaction force against the pressing force of the elastomer 17c.

The control unit 50c generates a braking request signal based on a depression signal received from a pedal travel sensor (not shown). The pedal request signal is an electrical signal that causes at least some of the plurality of wheel brakes (not shown) to generate a braking force.

The control unit 50c calculates the total braking force required for decelerating the vehicle based on a negative pressure signal. In addition, the control unit 50c determines whether one or more brakes, i. H. regenerative braking or hydraulic braking, are to be performed and may apply regenerative braking force or otherwise control the electric brake booster unit 20c depending on whether regenerative braking and/or hydraulic braking is being performed. In this case, the total requested braking force may be the sum of a hydraulic braking force and a regenerative braking force. In braking mode, a variety of modes can be set. For example, the control mode 50c can set a hydraulic braking mode in which only hydraulic braking force is used for braking, a regenerative braking mode in which only regenerative braking force is used for braking, and a combined braking mode in which both hydraulic braking force and one regenerative braking force to brake a vehicle.

21 12 is a schematic diagram illustrating the relationship between an elastic reaction disc, an operating rod, and a motor piston, and pedaling force.

21A 12 is a schematic view showing pedal force versus displacement of operating rod 12c with displacement of reaction disk 420c unchanged. 21B 14 is a schematic representation of pedal force versus the magnitude of pressure applied in master cylinder 14c when the relative displacement of motor piston 28c and actuating rod 12c is constant.

Out of 21A It can be seen that the pedaling force increases as the actuating rod 12c moves toward the reaction disk 420c, and the pedaling force decreases as it moves in the opposite direction. However, the pedaling force that a driver feels hardly changes when the difference between the displacement of the operating rod 12c and the displacement of the reaction disc 420c is within a predetermined range. This is because the reaction disc 420c is made of an elastic material.

Referring to 21B the difference between the displacement of the motor piston 28c and the displacement of the operating rod 12c is kept at a constant level, and when the hydraulic pressure in the master cylinder 14c is increased by depressing the reaction disk 420c, the pedal force felt by a driver increases in Corresponding to the magnitude of the hydraulic pressure in the master cylinder 14c and not to the displacement of the motor piston 28c and the actuating rod 12c.

22 Fig. 12 is a graph showing the relationship between total pedal force, pedal force of an elastomer, pedal force of a reaction disk, regenerative braking force, and hydraulic braking force over time when regenerative braking is stopped when a controller performs only regenerative braking during braking performs. 23 is a schematic diagram showing a process at a starting point and at times such as t ₁₃ in t ₁₄ 22 indicates.

In the diagrams in 22 , 24 , 26 and 28 L ₁ is the total pedaling force, L ₂ is the pedaling force of the elastomer 17c, L ₃ is the pedaling force of the reaction disc 420c, L ₄ is the regenerative braking force, and L ₅ is the hydraulic braking force.

23A shows operation to a starting point of 22 , 23B shows the operation at a time t ₁₃ from 22 , and 23C shows the operation at a time t ₁₄ from 22 .

The starting point of 22 is at point r ₁₁ where a driver starts to press the pedal 11c, and the entire pedaling force L ₁ is generated at the starting point. Because the operating rod 12c is spaced from the central portion 423c of the reaction disk 420c, no pedaling force L ₃ is yet generated by the reaction force of the reaction disk 420c. Only the pedaling force L ₂ of the elastomer increases in the period between the starting point, ie the starting point at which the driver starts to press the pedal 11c, and the time t ₁₀ .

In the period between times t ₁₀ and t ₁₁ , the pedaling force L ₃ increases by the reaction force of the reaction disk 420c. The motor piston 28c moves towards the master cylinder 14c and presses on the disk assembly 42c, thereby forming a central portion 423c protruding at the center of the reaction disk 420c. The center portion 423c comes into contact with the operating rod 12c at time t ₁₀ . As the degree of compression of the disc assembly 42c increases, pedaling force is made available to the rider through the operating rod 12c due to the reaction force of the reaction disc 420c. Accordingly, the total pedaling force L ₁ corresponding to the treadled amount of the pedal 11c increases in this period. However, as motor piston 28c moves toward master cylinder 14c and elastomer 17c expands, the increase in pedaling force through elastomer 17c may be less than the increase in total pedaling force L ₁ .

In the period between the starting point and time t ₁₁ no braking force is generated.

The period between times t ₁₁ and t ₁₂ is a period in which the treadled amount of the pedal 11c increases and a corresponding braking force is generated. 22 FIG. 14 shows a case where the control unit 50c starts the regenerative braking mode and a vehicle is decelerating, and in this period no hydraulic braking force L ₅ is generated and the regenerative braking force L ₄ gradually increases.

The period between times t ₁₂ and t ₁₃ is a period in which the amount of depression of the pedal 11c is maintained. Since the magnitude of the braking force requested by the driver does not change during this period, the regenerative braking force L ₄ is also kept at a constant level. At time t ₁₃ , as in 23B , the motor piston 28c pushes the disk unit 42c so that the displacement of the disk unit 42c moves from d ₁₁ to d ₁₂ as in FIG 23 shown, but not such that a hydraulic braking force L ₅ is generated.

The period between times t ₁₃ and t ₁₄ is a period in which the control unit 50c ends the regenerative braking mode and starts the hydraulic braking mode. In this period, the regenerative braking force decreases and the hydraulic braking force L ₅ increases by the reduced braking force. The period between times t ₁₃ and t ₁₄ is a period in which the hydraulic braking force L ₅ increases. The braking system according to the third embodiment of the present disclosure pushes the master cylinder 14c by moving the motor piston 28c from d ₁₂ to d ₁₃ by driving the electric booster unit 20c to generate hydraulic braking force in the period between times t ₁₃ and t ₁₄ . When time t ₁₄ is reached, as in 23C As shown, the displacement of the actuator rod 12c is not changed at r ₁₂ and only the displacement of the motor piston 28c changes.

wobei der P_rd1 Druck ist, der auf die Betätigungsstange 12c durch die Reaktionsschei-be 420c in 23B ausgeübt wird, A die Kontaktfläche zwischen der Reaktionsscheibe 420c und der Betätigungsstange 12c in 23B ist, K ein Elastizitätsmodul des Elastomers 17c ist, X₁ ein komprimierter Abstand des Elastomers 17c in 23B ist, P_rd2 Druck ist, der auf die Betätigungsstange 12c durch die Reaktionsscheibe 420c ausgeübt wird, und X₂ ein komprimierter Abstand des Elastomers 17c in 27C ist.If the pedal force that a driver in 23B senses, F is ₁ and the pedal force that a driver in 23C senses is equal to F ₂ , then F ₁ and F ₂ satisfy Equation 1. $$\begin{array}{c}{\text{<figure-callout id="1" label="f" filenames="DE102022104252A1\_0010.png,DE102022104252A1\_0015.png" state="{{state}}">f</figure-callout>}}_1={\text{P}}_{\text{approx}1}\text{A}+{\text{KX}}_1\\ {\text{<figure-callout id="2" label="f" filenames="DE102022104252A1\_0004.png,DE102022104252A1\_0017.png" state="{{state}}">f</figure-callout>}}_2={\text{P}}_{\text{approx}2}\text{A}+{\text{<figure-callout id="2" label="KX" filenames="DE102022104252A1\_0004.png,DE102022104252A1\_0017.png" state="{{state}}">KX</figure-callout>}}_2\end{array}$$

where P _rd1 is pressure exerted on actuator rod 12c by reaction disk 420c in 23B is applied, A is the contact area between the reaction disk 420c and the operating rod 12c in 23B is, K is a modulus of elasticity of the elastomer 17c, X ₁ is a compressed one Distance of the elastomer 17c in 23B , P _rd2 is pressure applied to actuation rod 12c by reaction disk 420c, and X ₂ is a compressed distance of elastomer 17c in 27C is.

The displacement of the operating rod 12c is maintained at the point r ₁₂ but that of the motor piston 28c moves from the point d ₁₂ to the point d ₁₃ in between 23B and 23C , so X ₁ > X ₂ . Accordingly, KX ₁ >KX ₂ .

Since the hydraulic braking force is reduced by the regenerative braking force in 23C is to be increased, the motor piston 28c must be moved further towards the cylinder 14c. Since the motor piston 28c pushes the reaction disk 420c more while the displacement of the operating rod 12c is maintained, the central part 423c of the reaction disk 420c, which is made of an elastic material, protrudes further and the reaction disk 420c has a larger pressure (P _rd1 < P _rd2 ). In this case, even if the degree of protrusion of the center part 423c of the reaction disk 420c increases, the contact area between the center part 423c and the operating rod 12c does not change.

Since P _rd1 < P _rd2 but KX ₁ > KX ₂ , F ₁ ≈ F ₂ . Accordingly, the driver can feel the pedal force even when the regenerative braking force decreases and the hydraulic braking force increases.

In the present disclosure, since the reaction disk 420c is made of an elastic material, the degree of protrusion and the area that contacts the operating rod 12c may depend on the degree of elasticity of the reaction disk 420c. Preferably, the reaction disc 420c is designed to satisfy F ₁ ≈F ₂ such that there is no difference between the pedal force F ₁ and F ₂ that a driver feels even when regenerative braking force decreases and hydraulic braking force increases.

24 is a graph showing the relationship among the total pedaling force, the pedaling force of an elastomer, the pedaling force of a reaction disc, a regenerative braking force, and the hydraulic braking force over time when a depression amount increases while regenerative braking is stopped in a situation where a control unit performs only regenerative braking during braking. 25 is a schematic diagram showing a process at a starting point and at times t ₂₃ and t ₂₄ 24 indicates.

25A shows operation to a starting point of 24 , 25B shows the operation at a time of t ₂₃ from 24 , and 25c shows the operation at a time t ₂₄ from 24 . The operation of the braking system in the period between the starting point of the diagram and the in 24 The point in time t ₂₃ shown is similar to the operation in the period between the starting point of the diagram and the point in 22 shown time t ₁₃ and is therefore not described below.

At time t ₂₃ , the control unit 50c stops the regenerative braking mode and begins to adjust the hydraulic braking mode. In the period between times t ₂₃ and t ₂₄ , the regenerative braking force L ₄ decreases and the hydraulic braking force L ₅ increases, but a driver increases the negative pressure amount in this period, as in FIG 24 shown such that the requested hydraulic braking force L ₅ is greater than the available maximum regenerative braking force L ₄ .

The increase in hydraulic braking force L ₅ is in the period between times t ₂₃ and t ₂₄ from 24 greater than in the period between times t ₁₃ and t ₁₄ of 22 .

According to the brake system of the third embodiment of the present disclosure, the driver does not feel the interruption of the braking effect even in this case. This is described in detail below.

As in 25B and 25C As shown, the displacement of the actuating rod 12c moves from r ₂₂ to r ₂₃ as the driver increases the pressure. The motor piston 28c is also driven by the electric booster unit 20c and presses on the disc unit 42c so that the disc unit 42c pushes on the master cylinder 14c as its displacement moves from d ₂₂ to d ₂₃ thereby generating hydraulic pressure. When the pressure applied to the reaction disc 420c gradually increases, the center portion 423c protrudes further and the pressure applied to the operating rod 12c increases due to a corresponding reaction force. As a result, the magnitude of the pedaling force L ₃ against the reaction force of the reaction disk 420c increases, but the elastomer 17c expands, so the magnitude of the pedaling force L ₂ through the elastomer 17c decreases. The principle of Equation 1 is applied as it is in this case, so that a driver does not feel the depression break even if the hydraulic change in the master cylinder 14c changes. That is, the motor piston 28c pushes the reaction disk 420c, so that the pedaling force L ₃ of the reaction disk 420c increases. In addition, the motor piston 28c moves toward the master cylinder 14c, so that the elastomer 17c expands and the pedaling force L ₂ of the elastomer 17c decreases. To the accordingly, the driver does not feel any interruption of the pedal force.

26 is a graph showing the relationship between the total pedal force, the pedal force of an elastomer, the pedal force of a reaction disk, a regenerative braking force and the hydraulic braking force over time when regenerative braking is stopped in a situation where a control unit performs regenerative braking and performs hydraulic braking during braking. 27 Fig. 12 is a schematic diagram showing an operation at a starting point and times t ₃₄ and t ₃₅ in 26 indicates.

27A shows operation to a starting point of 26 , 27B shows the operation at a time of t ₃₄ from 26 , and 27C shows the operation at a time t ₃₅ from 26 .

The process of generating the pedal force of the braking system in the period between the starting point of the diagram and the in 26 The point in time t ₃₂ shown is similar to the process in the period between the starting point of the diagram and the point in 22 shown time t ₁₂ and is therefore not described below.

At the starting point of 26 is a point where a driver starts to operate the pedal 11c, and at this point the operating rod 12c is positioned at r ₃₁ and the total pedaling force L ₁ is generated. Since the operating rod 12c is spaced from the central portion 423c of the reaction disk 420c, no pedaling force L ₃ is generated by the reaction force of the reaction disk 420c.

In the period between times t ₃₀ and t ₃₁ , which are times when the driver operates the pedal 11c, no braking force is generated. During this period, the pedaling force L ₂ generated by the compression of the elastomer 17c and the contact of the reaction disc 420c increases.

The period between times t ₃₁ and t ₃₂ is a period in which the treadled amount of the pedal 11c increases and a corresponding braking force is generated. 26 14 shows a case where the control unit 50c first starts the regenerative braking mode and brakes a vehicle, and in this period no hydraulic braking force L ₅ is generated and the regenerative braking force L ₄ gradually increases.

The time period between times t ₃₂ and t ₃₃ is a time period in which the controller 50c determines that the hydraulic braking mode should be started, e.g. B. that the driver should press the pedal 11c further, and the hydraulic braking force L ₅ is generated. During this period, the regenerative braking force L ₄ is maintained, but the electric booster unit 20c is driven and pushes the motor piston 28c, increasing the hydraulic pressure supplied to the plurality of wheel brakes (not shown). With this operation, the operating rod 12c moves further toward the master cylinder 14c, thereby pressing on the protruding central part 423c of the reaction disc 420c. The operating rod 12c comes into contact with the central part 423c of the reaction disk 420c, so that the driver additionally feels the pedaling force L ₃ of the reaction disk 420c. In this case, the total pedaling force L ₁ is the sum of the pedaling force L ₂ of the elastomer 17c and the pedaling force L ₃ of the reaction disc 420c.

The period between times t ₃₃ and t ₃₄ is a period in which the amount of depression of the pedal 11c is maintained. Since the magnitude of the braking force requested by the driver does not change during this period, the regenerative braking force L ₄ and the hydraulic braking force L ₅ are also kept at a constant level. At time t ₃₄ , as in 27B , the motor piston 28c presses on the disk unit 42c, so that the displacement of the disk unit 42c is as in FIG 27 shown moves to d ₃₂ and passes the point d ₀ which is a point where the hydraulic braking force L ₅ starts to be generated. By pushing the motor piston 28c, the middle part 423c of the reaction disc 420c protrudes further than in 27A shown and comes into contact with the operating rod 12c. In this period, when the driver increases the amount of pressure to generate the hydraulic braking force L ₅ , the displacement of the operating rod 12c moves to r ₃₂ .

The period between times t ₃₄ and t ₃₅ is a period in which the control unit 50c ends the regenerative braking mode and increases the hydraulic braking force by the reduced regenerative braking force.

The brake system according to the third embodiment of the present disclosure further pushes the master cylinder 14c by moving the motor piston 28c from d ₃₂ to d ₃₃ by driving the electric booster unit 20c to increase the hydraulic braking force in the period between times t ₃₄ and t ₃₅ to increase. When time t ₃₅ is reached, as in 27C As shown, the displacement of the actuator rod 12c is not changed at r ₃₂ and only the displacement of the motor piston 28c changes. Since the operating rod 12c remains in contact with the reaction disk 420c, the total pedaling force L ₁ becomes the pedaling force L ₂ of the elastomer 17c and the pedaling force L ₃ of reaction disk 420c is affected. Although affected by the pedaling force L ₃ of the reaction disc 420c, the magnitude of the total pedaling force L ₁ does not change as described in Equation 1. That is, the motor piston 28c pushes the reaction disk 420c, so that the pedaling force L ₃ of the reaction disk 420c increases. In addition, the motor piston 28c moves toward the master cylinder 14c, so that the elastomer 17c expands and the pedaling force L ₂ of the elastomer 17c decreases. Accordingly, the driver does not feel any interruption in the pedal force.

28 Fig. 12 is a graph showing the relationship among the total pedaling force, the pedaling force of an elastomer, the pedaling force of a reaction disc, a regenerative braking force, and the hydraulic braking force over time when a suppression amount increases while regenerative braking is stopped in a situation where a control unit performs both regenerative and hydraulic braking during braking. 29 Fig. 12 is a schematic diagram showing an operation at a starting point and times t ₄₄ and t ₄₅ in 28 indicates.

29A shows operation to a starting point of 28 , 29B shows the operation at a time t ₄₄ from 28 , and 29C shows the operation at a time t ₄₅ from 28 . The operation of the braking system in the period between the starting point of the diagram and the in 28 The point in time t ₄₄ shown is similar to the operation in the period between the starting point of the diagram and the point in 26 shown time t ₃₄ and is therefore not described below.

At time t ₄₄ the control unit 50c controls the electric booster unit 20c to end the regenerative braking mode and increase the hydraulic braking force L ₅ . In the period between times t ₄₄ and t ₄₅ , the regenerative braking force L ₄ decreases and the hydraulic braking force L ₅ increases, but a driver increases the suppression amount in this period, as in FIG 28 shown such that the requested hydraulic braking force L ₅ is greater than the available maximum regenerative braking force L ₄ .

The increase in hydraulic braking force L ₅ is in the period between times t ₄₄ and t ₄₅ from 28 greater than in the period between times t ₃₄ and t ₃₅ from 26 .

According to the brake system of the third embodiment of the present disclosure, the driver does not feel the break of the negative pressure in this case either.

As in 29B and 29C As shown, the displacement of the actuating rod 12c moves from r ₄₂ to r ₄₃ as the driver increases the pressure. The motor piston 28c is also driven by the electric amplifier unit 20c and presses on the reaction disc 420c so that the disc unit 42c pushes on the master cylinder 14c as it moves from d ₄₂ to d ₄₃ displacement, thereby creating hydraulic pressure. While driving from 29B to 29C the operating rod 12c remains in contact with the central portion 423c of the reaction disc 420c, but the pedaling force felt by the rider changes little as described with reference to the equations. Accordingly, even if the hydraulic pressure in the master cylinder 14c changes, the driver does not feel the depression break.

30 14 is a flow chart of a method for controlling a brake system according to a third embodiment of the present disclosure. The flowchart of 30 FIG. 12 shows some of many braking methods, and the control unit 50c does not necessarily include the algorithm of FIG 30 and can use a variety of braking algorithms including the algorithm of 30 include. 30 14 is a flowchart constructed on the assumption that a regenerative braking unit is driven, although the control unit 30c may include other methods of braking a vehicle using only hydraulic braking force.

The control unit 50c receives a brake pedal signal (S10c). That is, the control unit 50c receives a signal from the brake pedal 11c to check whether a driver operates the pedal 11c. If no brake pedal signal is received, the control unit 50c determines that there is no braking situation and executes the control process of 30 not through.

When a braking signal is received, the control unit 50c calculates a total requested braking force (S20c). The total requested braking force is determined based on the operation amount of the pedal 11c by the driver, and may be determined based on additional determination by a control unit 50c having a self-driving function. When the driver operates the pedal 11c, the control unit 50c calculates a total requested braking force for decelerating the vehicle based on the operating amount of the pedal 11c measured by a pedal travel sensor (not shown).

The control unit 50c calculates a requested regenerative braking force based on the total requested braking force (S20c). After calculating the requested regenerative braking force, the control unit 50c drives the regenerative braking unit (not shown) based on the calculated requested regenerative braking force (S40c).

While the regenerative braking unit (not shown) is being driven, the controller 50c determines whether the regenerative braking needs to be stopped (S50c). The control unit 50c can itself determine whether the regenerative braking should be stopped, but it can also determine whether the regenerative braking should be stopped based on a regenerative braking stop signal received from the outside.

When determining that the regenerative braking is stopped, the control unit 50c calculates a requested hydraulic braking force due to the stop of the regenerative braking (S60c). When the control unit 50c ends the regenerative braking mode, the regenerative braking force decreases, so the control unit 50c detects the magnitude of the regenerative braking force and calculates a requested hydraulic braking force for compensation according to the detected braking force.

The control unit 50c calculates the requested displacement of the motor piston 28c depending on the requested hydraulic braking force (S70c). The requested displacement of the motor piston 28c is determined based on the displacement of the motor piston 28c at the time the controller 50c begins to end regenerative braking.

The control unit 50c controls the electric booster unit 20c so that the motor piston 28c moves by the requested displacement (S80c). The control unit 40c moves the motor piston 28c toward the master cylinder 14c to push the reaction disc 420c by driving the electric assist unit 20c. In this case, the reaction disk 420c is made of an elastic material, and the motor piston 28c can come into contact with the outer edge of the reaction disk 420c.

As the motor piston 28c moves the desired distance, the control unit 50c controls so that the magnitude of the pedal force felt by the driver is fully maintained with the aid of the elastomer 17c and the reaction disc 420c (S90c).

In this case, the first end of the elastomer 17c is in contact with the brake pedal 11c and the second end is in contact with part of the electric brake booster 20c, so that when the motor piston 14c moves towards the master cylinder 14c, the driver's pedaling force is reduced can be.

When the motor piston 28c pushes on the reaction disc 420c, the middle part 423c of the reaction disc 420c can protrude towards the actuating rod 12c. When the protruding reaction disc 420c comes into contact with the operating rod 12c, the reaction disc provides a reaction force to the operating rod 12d, the reaction force being part of the pedaling force felt by the rider. According to the present disclosure, as described with reference to the equation, although the reaction disk 420c and the operating rod 12c come into contact with each other, there is no break in negative pressure in the period in which the regenerative braking force decreases and the hydraulic braking force increases.

The method terminates this algorithm after completing S90c.

The brake logic 22 until 30 is an example, the present disclosure does not reduce the vacuum interruption by a driver who uses only the braking logic shown in the figures, and the present disclosure can prevent the vacuum interruption by a driver who uses any braking logic.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• KR 1020210023791 [0001]
• KR 1020210059777 [0001]

Claims (17)

A braking system configured to perform cooperative braking in which both regenerative braking and hydraulic braking are performed in a braking situation of a vehicle, the braking system comprising: a master cylinder; a reaction disc made of an elastic material and configured to compress the master cylinder; a rod assembly having an operating rod whose displacement is adjusted based on a force applied to a brake pedal, an elastomeric mounting unit, and an elastomer having one end abutting a portion of the operating rod and the other end abutting the elastomeric mounting unit, an electric booster having a motor piston configured to compress at least a portion of the reaction disk to compress the master cylinder by adjusting a displacement of the motor piston; and an electric controller configured to control the electric booster and perform control to brake the vehicle using at least one of regenerative braking and hydraulic braking. braking system after claim 1 wherein if the electric controller brakes the vehicle by performing at least one of regenerative braking, among regenerative braking and hydraulic braking, the controller drives the electric booster to compress the reaction disc when regenerative braking is disabled. braking system after claim 1 or 2 wherein the actuating rod is configured to compress a central portion of the reaction disk and the motor piston is configured to compress an outer periphery of the reaction disk. Braking system according to one of Claims 1 until 3 wherein, if the motor piston compresses the reaction disc, the central part of the reaction disc protrudes toward the operating rod depending on a degree of compression, thereby forming a protruding portion. Braking system according to one of Claims 1 until 4 , wherein when the protruding portion abuts against the operating rod while the brake pedal is depressed, a pressure applied from the reaction disk to the operating rod increases with increasing pressure applied to the reaction disk by the engine piston, and at the same time a Contact area between the reaction disc and the actuating rod decreases. Braking system according to one of Claims 1 until 5 wherein if the hydraulic pressure is maintained in the master cylinder, if the motor piston moves further towards the reaction disk than the actuating rod and the displacement of the motor piston and the displacement of the actuating rod are equal, an amount of pedal force is maintained no matter how strong the master cylinder is compressed by the reaction disc. Braking system according to one of Claims 1 until 6 , wherein the elastomer comprises at least one spring between the spring and a damper. A method for controlling a braking system configured to perform cooperative braking during braking of a vehicle, in which both regenerative braking and hydraulic braking are performed, the method comprising: (a) when a pedal is operated, calculating a total braking force required to brake the vehicle based on a pedal stroke measured by a pedal travel sensor; (b) calculating a required regenerative braking force based on the total required braking force, (c) operating a regenerative braking unit to provide a braking force corresponding to the required regenerative braking force; (d) determining whether or not to terminate regenerative braking; (e) if it is determined that regenerative braking needs to be discontinued, calculating a required hydraulic braking force corresponding to discontinuation of regenerative braking; (f) calculating a required displacement of an engine piston that corresponds to the required hydraulic braking force; and (g) driving an electrical boost to compress a reaction disc by moving the motor piston according to the required displacement. procedure after claim 8 , wherein the engine piston is made of an elastic material. procedure after claim 8 or 9 , wherein the engine piston is configured to compress an outer periphery of the reaction disk. Procedure according to one of Claims 8 until 10 , wherein in step (g), when the engine piston compresses the reaction disk, an amount of reaction force formed is constant. Procedure according to one of Claims 8 until 11 wherein in step (f) the required displacement is calculated as a function of whether the reaction disc is in abutment with the actuating rod, the displacement of which is adjusted as a function of an amount of force exerted on a brake pedal. Procedure according to one of Claims 8 until 12 , further comprising a step of performing control such that a magnitude of a pedaling force is fully maintained using the reaction disk and an elastomer whose first end is in contact with a brake pedal and whose second end is in contact with a portion of the electric booster while the engine piston moves by the desired displacement. Braking system configured to perform cooperative braking in which both regenerative braking and hydraulic braking are performed in a braking situation of a vehicle, the braking system comprising: a master cylinder; a reaction disc made of an elastic material and configured to push the master cylinder; an electric booster having a motor piston configured to push at least a portion of the reaction disk and a screw shaft configured to push the motor piston and configured to push the master cylinder by adjusting a displacement of the motor piston; a rod assembly having an operating rod whose displacement is adjusted depending on a depression amount of a brake pedal, and further comprising an elastomer having a first end in contact with a portion of the operating rod and a second end in contact with at least a portion of the electric booster; and a controller configured to control the electric booster and perform control for braking the vehicle using at least one of regenerative braking and hydraulic braking. braking system after Claim 14 , wherein the elastomer is in contact with the motor piston or the screw shaft of the electric brake booster. braking system after Claim 14 or 15 , wherein the screw shaft has a first shaft configured to rotate and a second shaft configured to push the motor piston by converting a rotary motion of the first shaft into a linear motion, and the elastomer in contact with the second wave is. Braking system according to one of Claims 14 until 16 wherein when the controller brakes the vehicle by performing the regenerative braking and/or the hydraulic braking, the controller drives the electric booster to push the reaction disc when the regenerative braking stops.

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