Electro-Mechanical Brake Apparatus And Method Therefor

Abstract

An electric brake device is disclosed. According to one embodiment of the present disclosure, an electric brake device comprises: a main controller that determines a braking command for a vehicle; a plurality of wheel controllers that receive a braking signal based on the braking command from the main controller and control braking actuators disposed on each wheel of the vehicle to generate a braking clamping force on each wheel; and a plurality of temperature sensors each included in the plurality of wheel controllers and configured to measure the internal temperature of each of the plurality of wheel controllers, wherein the plurality of wheel controllers estimate a friction coefficient value between a friction pad included in each wheel and a brake disc using internal temperature values ​​measured from the plurality of temperature sensors, information based on the braking command, and information regarding the cooling conditions of each wheel, and change the unit pressure reduction amount during wheel slip prevention control using the estimated friction coefficient value.

Description

Technology Field

[0001] The present disclosure relates to an electric brake device and a method for controlling the same. Background Technology

[0002] The content described in this section merely provides background information regarding the present disclosure and does not constitute prior art.

[0003] Electro-mechanical brakes are equipped with motor-based drive actuators. Unlike hydraulic mechanisms that utilize hydraulic pressure, electro-mechanical brakes employ mechanical mechanisms such as gears and screws. In particular, electro-mechanical brakes generate clamping force between the friction pad and the brake disc by using a piston that moves forward or backward using the driving force of a motor.

[0004] These electric brakes enable active braking based on driving conditions and allow for independent braking of each wheel. Therefore, electric brakes support not only general braking but also braking controls such as ABS (Anti-lock Brake System), ESC (Electronic Stability Control), TCS (Traction Control System), and AEB (Autonomous Emergency Braking). Furthermore, unlike hydraulic mechanisms, electric brakes can achieve higher braking performance because there is no delay in generating braking clamping force.

[0005] In the aforementioned ABS control, the controller controlling the vehicle's braking reduces the braking clamping force applied to the brake disc when wheel slip occurs, and repeats the process of restoring the wheel speed when wheel slip does not occur, thereby preventing wheel lock caused by wheel slip. However, during repeated braking of the braking system, the temperature of the brake disc rises, and the coefficient of friction with the friction pad decreases for the brake disc with a rise in temperature. This lowers the sensitivity of changes in braking clamping force based on changes in unit braking pressure (clamping force). Therefore, when the temperature of the brake disc is high, a large amount of reduction in braking clamping force is required. Consequently, as the estimation error of the brake disc temperature increases, the time required to reduce the braking clamping force increases, and there is a problem in that slip may not be prevented, potentially leading to deep slip. The problem to be solved

[0006] Accordingly, the present disclosure aims to solve these problems, and its primary purpose is to increase the ABS control performance of an electric brake system under high temperature conditions using a brake disc.

[0007] The problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by a person skilled in the art from the description below. means of solving the problem

[0008] According to one embodiment of the present disclosure, an electric brake device comprises: a main controller that determines a braking command for a vehicle; a plurality of wheel controllers that receive a braking signal based on the braking command from the main controller and control braking actuators disposed on each wheel of the vehicle to generate a braking clamping force on each wheel; and a plurality of temperature sensors each included in the plurality of wheel controllers and configured to measure the internal temperature of each of the plurality of wheel controllers, wherein the plurality of wheel controllers estimate a friction coefficient value between a friction pad included in each wheel and a brake disc using internal temperature values ​​measured from the plurality of temperature sensors, information based on the braking command, and information regarding the cooling conditions of each wheel, and change the unit pressure reduction amount during wheel slip prevention control using the estimated friction coefficient value.

[0009] According to one embodiment of the present disclosure, a control method for an electric brake device comprises: a process of estimating the temperature of a brake disc based on information based on a braking command transmitted from a main controller to a plurality of wheel controllers, wheel speed values ​​of each wheel, and internal temperature values ​​of each of the plurality of wheel controllers; a process of calculating a friction coefficient value using a lookup table based on the estimated temperature of the brake disc; a process of setting a unit pressure reduction amount to reduce or increase / decrease the braking clamping force during wheel slip control based on the calculated friction coefficient value; and a process of performing wheel slip prevention control based on the set unit pressure reduction amount. Effects of the invention

[0010] According to one embodiment, the electric brake device has the effect of increasing the ABS control performance of the electric brake device under high temperature conditions using a brake disc. Brief explanation of the drawing

[0011] FIG. 1 is a drawing showing the configuration of an electric brake device according to one embodiment of the present disclosure. FIG. 2 is a block diagram showing a part of the configuration of an electric brake device according to one embodiment of the present disclosure. FIG. 3 is a graph showing the change in braking clamping force based on wheel slip prevention control of an electric brake device according to one embodiment of the present disclosure. FIG. 4 is a flowchart illustrating a control method for an electric brake device according to one embodiment of the present disclosure. Specific details for implementing the invention

[0012] Some embodiments of the present disclosure are described in detail below with reference to the exemplary drawings. It should be noted that in assigning reference numerals to the components of each drawing, the same components are given the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the present disclosure, if it is determined that a detailed description of related known components or functions could obscure the essence of the present disclosure, such detailed description is omitted.

[0013] In describing the components of the embodiments according to the present disclosure, symbols such as first, second, i), ii), a), b), etc., may be used. These symbols are intended only to distinguish the components from other components, and the essence, order, or sequence of the components is not limited by the symbols. When a part in the specification is described as 'comprising' or 'having' a component, this means that, unless explicitly stated otherwise, it does not exclude other components but may include additional components.

[0014] Where it is stated that one component is 'connected', 'combined', or 'joined' to another component, it should be understood that while the component may be directly connected or joined to the other component, another component may also be 'connected', 'combined', or 'joined' between each component.

[0015] Terms such as 'part', 'module', etc., as described in the specification refer to a unit that processes at least one function or operation, and this may be implemented in hardware, software, or a combination of hardware and software.

[0016] Unless otherwise stated, it should be noted that the description of any one embodiment may also apply to other embodiments.

[0017] The description of the invention disclosed below, together with the accompanying drawings, is intended to describe exemplary embodiments of the invention and is not intended to represent the only embodiment in which the invention may be practiced.

[0018] FIG. 1 is a drawing showing the configuration of an electric brake device according to one embodiment of the present disclosure.

[0019] Referring to FIG. 1, an electric brake device (10) according to one embodiment of the present disclosure includes some or all of a main controller (100), an auxiliary controller (101), a plurality of electro-mechanical brakes (110, 120, 130 and 140), a plurality of wheel controllers (111, 121, 131 and 141), a first power supply (150), and a second power supply (160).

[0020] Although not disclosed in FIG. 1, the main controller (100) according to the present disclosure may be connected to a pedal simulator (not shown).

[0021] Additionally, the main controller (100) may be connected to a yaw rate sensor unit. Here, the yaw rate sensor unit is a sensor that detects vibration changes and electronically measures the yaw moment when the vehicle rotates relative to a vertical axis formed perpendicular to the ground. The yaw rate sensor unit may include, for example, a Steering Angle Sensor (SAS, not shown) and a Yaw Rate Sensor (YRS, not shown). The value measured by the yaw rate sensor unit may be transmitted to the main controller (100) via, for example, a chassis CAN and a body CAN (Controller Area Network).

[0022] The main controller (100) may include, for example, some or all of a first pedal sensor (not shown), a second pedal sensor (not shown), a BLS (Brake Light Signal sensor, not shown), an IGN sensor (ignition signal sensor, not shown), a door switch sensor (not shown), an ESC sensor (Electronic Stability Control sensor, not shown), and an AVH switch (Auto Vehicle Hold switch, not shown).

[0023] The main controller (100) according to the present disclosure can generate braking commands related to driving and braking of a vehicle. The main controller (100) can transmit and receive signals related to braking commands with a plurality of wheel controllers (111, 121, 131 and 141) using a first communication line (170) and a second communication line (180).

[0024] The first communication line (170) and the second communication line (180) are configured to transmit and receive signals between the main controller (100), the auxiliary controller (101), and a plurality of wheel controllers (111, 121, 131 and 141).

[0025] The second communication line (180) may be a redundancy communication line capable of performing backup communication when a problem occurs in the first communication line (170).

[0026] The auxiliary controller (101) may be physically integrated with the main controller (100) or configured separately and connected signal-wise.

[0027] Although not illustrated in FIG. 1, the auxiliary controller (101) according to the present disclosure may include some or all of a third pedal sensor (first pedal sensor, not shown), a fourth pedal sensor (second pedal sensor, not shown), a BLS (Brake Light Signal sensor, not shown), an IGN sensor (ignition signal sensor, not shown), and a door switch sensor (not shown).

[0028] The auxiliary controller (101) according to the present disclosure may be connected to the aforementioned yaw rate sensor unit.

[0029] The auxiliary controller (101) according to the present disclosure performs the role of control redundancy for the main controller (100). For example, if abnormal operation of the main controller (100) is detected or a failure occurs, the auxiliary controller (101) can receive control rights related to driving and braking from the main controller (100) and perform control related to the driving of the vehicle.

[0030] A plurality of electric brakes (110, 120, 130, and 140) according to the present disclosure may be disposed on each wheel (FL, FR, RL, and RR) of a vehicle. The plurality of electric brakes (110, 120, 130, and 140) can perform braking of the wheels by converting the kinetic energy of the vehicle into thermal energy using frictional force.

[0031] Multiple electric brakes (110, 120, 130 and 140) can generate braking clamping force using motor-based actuators.

[0032] A plurality of electric brakes (110, 120, 130 and 140) may include some or all of a pressurizing part (not shown), a friction pad (not shown), a current sensor (not shown), and a motor rotation angle sensor (not shown).

[0033] Multiple electric brakes (110, 120, 130, and 140) can generate rotational force and transmit it to the pressurizing part. The motor may be a DC motor, an AC motor, an induction motor, a synchronous motor, a step motor, a servo motor, a brushless motor, a linear motor, or a permanent magnet synchronous motor (PMSM), etc.

[0034] The pressurizing part may include some or all of a gearbox (not shown), a screw (not shown), a nut (not shown), and a piston (not shown).

[0035] The gearbox may include multiple gears. The gearbox can distribute rotational force by using rotational force received from a motor to mesh and rotate multiple gears.

[0036] The screw can receive assisted rotational force from the gearbox. The screw converts the assisted rotational force into linear motion to pressurize or depressurize the piston. The nut is positioned so that rotation is restricted.

[0037] Friction pads can be placed on both sides of the brake disc. When the piston is pressurized, the friction pads can be pressed from both sides of the brake disc. When the pressurizing part presses the friction pad against the brake disc, the friction pad is compressed, and a braking clamping force is generated. Here, the point where the braking clamping force begins to occur is called the contact point. The braking clamping force increases or decreases depending on the degree to which the friction pad is compressed by the movement of the pressurizing part from the contact point toward the brake disc.

[0038] The electric brake device (10) according to the present disclosure can ensure braking stability of the vehicle by changing the unit pressure reduction amount of the braking clamping force during wheel slip prevention control according to the changing temperature of the friction pad.

[0039] A plurality of wheel controllers (111, 121, 131, and 141) according to the present disclosure can generate braking force using a plurality of electric brakes (110, 120, 130, and 140) based on a braking command received from a main controller (100). The plurality of wheel controllers (111, 121, 131, and 141) are arranged adjacent to the plurality of electric brakes (110, 120, 130, and 140).

[0040] A plurality of wheel controllers (111, 121, 131 and 141) according to the present disclosure may produce an independent braking command even if they do not receive a braking command received from the main controller (100).

[0041] Although not illustrated in FIG. 1, each of the plurality of wheel controllers (111, 121, 131, and 141) includes a wheel speed sensor. The wheel speed sensor may be positioned adjacent to the brake disc. The wheel speed sensor can measure the rotational speed of the brake disc, i.e., the wheel. A detailed description of the wheel speed sensor will be provided later in FIG. 2.

[0042] The first power supply unit (150) according to the present disclosure may be configured to supply power to the main controller (100), the left front wheel electric brake (110), and the right rear wheel electric brake (140).

[0043] The second power supply unit (160) according to the present disclosure may be configured to supply power to the auxiliary controller (101), the right front wheel electric brake (120), and the left rear wheel electric brake (130).

[0044] The second power supply unit (160) performs the redundancy function of the first power supply unit (150). For example, if a malfunction occurs in the first power supply unit (150), the main controller (100), the left front wheel electric brake (110), and the right rear wheel electric brake (140) that receive power from the first power supply unit (150) all become unusable. In this case, the auxiliary controller (101) that receives power from the second power supply unit (160) can perform emergency braking of the vehicle using the right front wheel electric brake (120) and the left rear wheel electric brake (130).

[0045] The first power supply unit (150) and the second power supply unit (160) are configured to supply power to the intersecting electric brakes among a plurality of electric brakes. For example, the first power supply unit (150) and the second power supply unit (160) can configure the power supply line in an X-split structure. In this case, since braking clamping force can be generated on at least one front wheel and at least one rear wheel, minimum braking stability of the vehicle can be secured.

[0046] FIG. 2 is a block diagram showing a part of the configuration of an electric brake device according to one embodiment of the present disclosure.

[0047] Referring to FIGS. 1 and 2, the left front wheel controller (111) according to the present disclosure receives information based on a braking command from the main controller (100). Additionally, the left front wheel controller (111) receives wheel speed information for the left front wheel from the left front wheel speed sensor (200).

[0048] The description of the left front wheel controller (111) illustrated in FIG. 2, which will be described below, may be applied in the same way to the right front wheel controller (121), left rear wheel controller (131), and right rear wheel controller (141) not illustrated in FIG. 2. In addition, the right front wheel controller (121), left rear wheel controller (131), and right rear wheel controller (141) may also be connected to or include the same configuration as the left front wheel speed sensor (200) connected to the left front wheel controller (111) and the left front wheel temperature sensor (210) included inside.

[0049] The left front wheel controller (111) according to the present disclosure can estimate the temperature of the brake disc using information based on a braking command received from the main controller (100) and wheel speed information received from the left front wheel speed sensor (200).

[0050] For example, to obtain the estimated temperature of the brake disc, the left front wheel controller (111) may use the temperature value measured by the left front wheel temperature sensor (210) included inside. Since the left front wheel temperature sensor (210) mounted inside the left front wheel controller (111) is located at a predetermined distance from the brake disc, it cannot directly measure the temperature of the brake disc. However, the measured value of the left front wheel temperature sensor (210) may increase or decrease depending on the temperature change of the brake disc. This is because the internal temperature of the left front wheel controller (111) may also rise depending on the application time of the braking clamping force of the left front electric brake (110), the number of times the braking clamping force is applied, etc. Therefore, when estimating the temperature value of the brake disc according to the present disclosure, the internal temperature value of the left front wheel controller (111) measured by the left front wheel temperature sensor (210) may be used.

[0051] In addition, to obtain the estimated temperature of the brake disc, the left front wheel controller (111) may use information based on a braking command. Here, the information based on the braking command may include information regarding the magnitude of the braking clamping force, the application time of the braking clamping force, and the number of times the braking clamping force is applied.

[0052] The left front wheel controller (111) can obtain the estimated temperature of the brake disc based on the following mathematical formula 1.

[0054] [Mathematical Formula 1]

[0055]

[0057] Referring to Equation 1, the estimated temperature refers to the temperature of the brake disc. Tc refers to the temperature inside the wheel controller. C1 and C2 may be constants with dimensions to correct Equation 1.

[0058] Referring to the variables disclosed in mathematical formula 1, in order to determine the estimated temperature of the brake disc according to the present disclosure, the left front wheel controller (111) may use the magnitude of the braking clamping force of the left front electric brake (110), the duration of the braking clamping force, and the number of times the braking clamping force is applied as variables.

[0059] The left front wheel controller (111) can collect information regarding the magnitude, duration, and number of applications of the braking clamping force generated from the left front electric brake (110) for a certain period of time. The left front wheel controller (111) can collect data related to braking during the vehicle's 10-minute driving period. For example, it is assumed that data is stored in which a braking clamping force of 0.2 g is applied once for 5 seconds, a braking clamping force of 0.3 g is applied twice for 3 seconds, and a braking clamping force of 0.1 g is applied three times for 4 seconds during the 10-minute period. In this case, the left front wheel controller (111) can determine the temperature value of the brake disc corresponding to the magnitude, duration, and number of applications of the stored braking clamping force.

[0060] Referring to the variables disclosed in mathematical formula 1, in order to determine the estimated temperature of the brake disc according to the present disclosure, the left front wheel controller (111) may use the wheel speed of the left front wheel and the non-braking driving time of the left front wheel as variables.

[0061] The left front wheel controller (111) according to the present disclosure can obtain information on cooling conditions according to wheel speed by using the wheel speed information of the left front wheel and the non-braking driving time of the left front wheel.

[0062] The left front wheel controller (111) can estimate the speed of the vehicle using the left front wheel speed value received from the left front wheel speed sensor (200). This is because, in normal driving conditions where there is no difference between the wheel speed and the vehicle speed, such as wheel slip, the wheel speed and the vehicle speed are the same.

[0063] The left front wheel controller (111) can estimate the degree of cooling of the brake disc based on the vehicle's driving speed. Here, the cooling rate of the brake disc estimated based on the vehicle's driving speed may be information stored in a lookup table using a pre-prepared simulation, etc.

[0064] The left front wheel controller (111) can calculate the estimated degree of cooling (cooling rate) of the brake disc relative to the vehicle's driving speed using a lookup table. For example, the vehicle's driving speed and the cooling rate of the brake disc will be proportional.

[0065] The left front wheel controller (111) according to the present disclosure may correct the estimated cooling rate of the brake disc based on additional information related to the temperature of the vehicle, such as weather conditions around the vehicle, in order to increase the estimation rate of the cooling rate of the brake disc based on the driving speed of the vehicle. Here, the additional information related to the temperature of the vehicle may include the non-braking driving time of the left front wheel.

[0066] The left front wheel controller (111) can calculate the friction coefficient value between the brake disc and the friction pad using a lookup table based on the estimated temperature value of the brake disc. The left front wheel controller (111) can calculate the friction coefficient value using a lookup table. Here, the lookup table may include data for the friction coefficient value corresponding to the temperature value of the brake disc.

[0067] The left front wheel controller (111) can determine the unit pressure reduction amount when controlling wheel slim of the vehicle based on the calculated friction coefficient value. This will be described in detail later in FIG. 3.

[0068] FIG. 3 is a graph showing the change in braking clamping force based on wheel slip prevention control of an electric brake device according to one embodiment of the present disclosure.

[0069] Referring to FIGS. 1 to 3, when the temperature of the brake disc is not a high-temperature condition, when wheel slip prevention control such as ABS (Anti-lock Brake System) is performed, the unit pressure reduction amount (F a Reduce the braking clamping force by ) and if it is determined that no slip has occurred on the wheel, reduce the braking clamping force again by a unit reduction amount (F a The process of increasing pressure by ) is repeated to prevent wheel lock caused by wheel slip.

[0070] Unit pressure reduction amount (F) determined without considering the temperature of the brake disc a When performing wheel slip prevention control that reduces and increases pressure by a certain amount, there is a problem that deep slip may occur. Therefore, the electric brake device (10) according to the present disclosure can prevent wheel slip by changing the sensitivity of the unit pressure reduction amount when the brake disc is under high temperature conditions. For example, when the temperature of the brake disc placed on each wheel is estimated to be high temperature, a plurality of wheel controllers (111, 121, 131 and 141) can calculate a friction coefficient value based on the estimated temperature value of the brake disc using a lookup table.

[0071] A plurality of wheel controllers (111, 121, 131, and 141) have a unit pressure reduction amount (F) that is reduced during wheel slip control based on a friction coefficient value calculated using a lookup table. c You can set ).

[0072] Multiple wheel controllers (111, 121, 131, and 141) have a set unit pressure reduction amount (F c By implementing wheel slip prevention control based on ), braking stability of the vehicle can be secured.

[0073] Braking torque is linearly proportional to the value calculated by multiplying the braking clamping force by the friction coefficient. Therefore, the unit pressure reduction amount can be changed by the ratio of the increase or decrease in the friction coefficient. For example, assuming the unit pressure reduction amount under normal conditions is 2 kN at the temperature of the brake disc, if the friction coefficient value under high-temperature conditions is calculated to be 10% higher than the normal condition by the aforementioned method for calculating the friction coefficient value, the unit pressure reduction amount can be set to 1.8 kN, which is a value reduced by 10%, because the sensitivity to changes in the braking clamping force has increased. Conversely, if the friction coefficient value under high-temperature conditions is calculated to be 20% lower than the normal condition by the aforementioned method for calculating the friction coefficient value, the unit pressure reduction amount can be set to 2.4 kN, which is a value increased by 20%, because the sensitivity to changes in the braking clamping force has decreased.

[0074] FIG. 4 is a flowchart illustrating a control method for an electric brake device according to one embodiment of the present disclosure.

[0075] Referring to FIGS. 1 to 4, a plurality of wheel controllers (111, 121, 131 and 141) estimate the temperature of the brake disc of each wheel based on information based on a braking command transmitted from the main controller (100), wheel speed values ​​of each wheel, and internal temperature values ​​of each of the plurality of wheel controllers (111, 121, 131 and 141) (S400). The main controller (100) can transmit information to the plurality of wheel controllers regarding the magnitude of the braking clamping force related to the braking of the vehicle, the application time of the braking clamping force, and the number of times the braking clamping force is applied.

[0076] Multiple wheel controllers (111, 121, 131, and 141) can calculate information on cooling conditions that are calculated in proportion to the wheel speed of each wheel using wheel speed information of each wheel measured from wheel speed sensors placed on each wheel. Multiple wheel controllers (111, 121, 131, and 141) can estimate the temperature of the brake disc based on information on wheel speed and cooling conditions, along with the magnitude of the aforementioned braking clamping force, the application time of the braking clamping force, and the number of times the braking clamping force is applied.

[0077] Multiple wheel controllers (111, 121, 131 and 141) calculate a friction coefficient value using a lookup table based on the estimated temperature of the brake disc (S410). The lookup table stores friction coefficient values ​​corresponding to the temperature of the brake disc obtained through a pre-designed simulation.

[0078] A plurality of wheel controllers (111, 121, 131 and 141) set a unit pressure reduction amount that reduces or increases the braking clamping force based on the calculated friction coefficient value during wheel slip control (S420). A plurality of wheel controllers (111, 121, 131 and 141) set a unit pressure reduction amount determined by a ratio corresponding to the increase or decrease of the friction coefficient value when wheel slip occurs, using the estimated friction coefficient value.

[0079] Multiple wheel controllers (111, 121, 131 and 141) perform wheel slip prevention control based on a set unit pressure reduction amount (S430).

[0080] Various embodiments of the systems and techniques described herein may be realized as digital electronic circuits, integrated circuits, field programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include being implemented as one or more computer programs executable on a programmable system. A programmable system comprises a storage system, at least one input device, and at least one programmable processor (which may be a special-purpose processor or a general-purpose processor) coupled to receive data and instructions from and transmit data and instructions to at least one output device. Computer programs (which are also known as programs, software, software applications, or code) include instructions for the programmable processor and are stored on a "computer-readable recording medium."

[0081] Computer-readable recording media include all types of recording devices in which data that can be read by a computer system is stored. Such computer-readable recording media may be non-volatile or non-transitory media such as ROM, CD-ROM, magnetic tape, floppy disk, memory card, hard disk, magneto-optical disk, and storage device, and may also include transitory media such as data transmission media. Additionally, computer-readable recording media may be distributed across networked computer systems, and computer-readable code may be stored and executed in a distributed manner.

[0082] Although the flowcharts and timing diagrams in this specification describe each process as being executed sequentially, this is merely an illustrative explanation of the technical concept of one embodiment of the present disclosure. In other words, a person skilled in the art to which one embodiment of the present disclosure belongs may modify and adapt the flowcharts and timing diagrams in various ways, such as changing the order described in the flowcharts and timing diagrams or executing one or more of the processes in parallel, without departing from the essential characteristics of one embodiment of the present disclosure; therefore, the flowcharts and timing diagrams are not limited to a chronological order.

[0083] The above description is merely an illustrative explanation of the technical concept of the present embodiment, and a person skilled in the art to which the present embodiment belongs would be able to make various modifications and variations within the scope of the essential characteristics of the present embodiment. Accordingly, the present embodiments are intended to explain, not limit, the technical concept of the present embodiment, and the scope of the technical concept of the present embodiment is not limited by these embodiments. The scope of protection of the present embodiment shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present embodiment. Explanation of the symbols

[0084] 10: Electric brake system 100: Main controller 101: Auxiliary Controller 110: Left front electric brake 111: Left front wheel controller 120: Right front wheel electric brake 121: Right front wheel controller 130: Left rear electric brake 131: Left rear wheel controller 140: Right rear electric brake 141: Right rear wheel controller 150: 1st power supply unit 160: Second power supply unit 170: First communication line 180: Second communication line

Claims

Claim 1 An electric brake device comprising: a main controller that determines a braking command of a vehicle; a plurality of wheel controllers that receive a braking signal based on the braking command from the main controller and control braking actuators disposed on each wheel of the vehicle to generate a braking clamping force on each wheel; and a plurality of temperature sensors each included in the plurality of wheel controllers and configured to measure the internal temperature of each of the plurality of wheel controllers, wherein the plurality of wheel controllers estimate a friction coefficient value between a friction pad included in each wheel and a brake disc using internal temperature values ​​measured from the plurality of temperature sensors, information based on the braking command, and information regarding the cooling conditions of each wheel, and change the unit pressure reduction amount during wheel slip prevention control using the estimated friction coefficient value. Claim 2 An electric brake device according to claim 1, wherein the plurality of wheel controllers estimate the temperature value of the brake disc using internal temperature values ​​measured from the plurality of temperature sensors and information regarding the magnitude of the braking clamping force, the application time of the braking clamping force, and the number of times the braking clamping force is applied received from the main controller. Claim 3 In claim 2, the plurality of wheel controllers calculate a friction coefficient value corresponding to an estimated temperature value of a brake disc based on a pre-stored lookup table, in an electric brake device. Claim 4 An electric brake device according to claim 1, wherein the plurality of wheel controllers receive wheel speed information of each wheel measured from wheel speed sensors disposed on each wheel, and calculate information on cooling conditions calculated in proportion to the wheel speed of each wheel using the received wheel speed information of each wheel. Claim 5 An electric brake device according to claim 1, wherein the plurality of wheel controllers determine a unit pressure reduction amount for reducing and increasing pressure when wheel slip occurs using an estimated friction coefficient value, wherein the unit pressure reduction amount is determined at a ratio corresponding to the increase or decrease of the estimated friction coefficient value. Claim 6 A method for controlling an electric brake device, comprising: a process of estimating the temperature of a brake disc based on information based on a braking command transmitted from a main controller to a plurality of wheel controllers, wheel speed values ​​of each wheel, and internal temperature values ​​of each of the plurality of wheel controllers; a process of calculating a friction coefficient value using a lookup table based on the estimated temperature of the brake disc; a process of setting a unit pressure reduction amount for reducing or increasing / decreasing the braking clamping force during wheel slip control based on the calculated friction coefficient value; and a process of performing wheel slip prevention control based on the set unit pressure reduction amount. Claim 7 In claim 6, the process of estimating the temperature of a brake disc based on information based on a braking command transmitted from a main controller to a plurality of wheel controllers, wheel speed values ​​of each wheel, and internal temperature values ​​of each of the plurality of wheel controllers is a process in which the main controller transmits information regarding the magnitude of the braking clamping force related to the braking of the vehicle, the application time of the braking clamping force, and the number of times the braking clamping force is applied to the plurality of wheel controllers, a control method for an electric brake device. Claim 8 In claim 6, the process of calculating a friction coefficient value using a lookup table based on the estimated temperature of the brake disc is a control method for an electric brake device that calculates a friction coefficient value between the brake disc and the friction pad using a lookup table in which friction coefficient values ​​corresponding to the temperature of the brake disc obtained through a pre-designed simulation are stored. Claim 9 In claim 6, the process of setting a unit pressure reduction amount for reducing or increasing / decreasing the braking clamping force based on a calculated friction coefficient value during wheel slip control is a control method for an electric brake device that sets a unit pressure reduction amount determined by a ratio corresponding to the increase or decrease of the friction coefficient value when wheel slip occurs, using an estimated friction coefficient value. Claim 10 A control method for an electric brake device according to claim 6, wherein the process of estimating the temperature of a brake disc based on information based on a braking command transmitted from a main controller to a plurality of wheel controllers, wheel speed values ​​of each wheel, and internal temperature values ​​of each of the plurality of wheel controllers further comprises the process of calculating information on cooling conditions calculated in proportion to the wheel speed of each wheel using wheel speed information of each wheel measured by wheel speed sensors disposed on each wheel.

Images