Electromechanical brake

Abstract

An electromechanical brake, comprising: a brake disc; a friction block; a pressing unit configured to press the friction block toward the brake disc; a motor that supplies power to the pressing unit; a current sensor; a position sensor configured to measure the position of the pressing unit; and an initial position calculation unit that calculates at least one of an initial position or a contact point of the pressing unit, wherein the pressing unit is configured to pass through a first check point and a second check point, a first current is measured at the first check point, and a second current greater than the first current is measured at the second check point, wherein the initial position calculation unit calculates at least one of the initial position or the contact point based on the first current, the first check point, the second current, and the second check point.

Description

Technical Field

[0001] The present disclosure relates to an electro-mechanical brake. More specifically, the present disclosure relates to an electro-mechanical brake having a position sensor and a current sensor. Background Art

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

[0003] Electro-Mechanical Brakes (EMBs) are being developed and widely used. The electro-mechanical brake has evolved from an Electronic Parking Brake (EPB), but its scope of use has recently been expanding to replace the main brake of a conventional hydraulic brake. An EMB is a device in which an actuator driven by an electric motor is mounted on a brake caliper, so that the vehicle is directly braked by the driving force of the electric motor without a medium such as brake fluid. Since the mechanism of the EMB is similar to that of an Electronic Parking Brake (EPB), but it is mainly used for the main brake, unlike the EPB. Compared with the EPB, the EMB requires higher braking response and operation durability. In addition, compared with a hydraulic brake, the electro-mechanical brake has a simpler structure, a higher braking response speed, and more precise control, thereby improving braking stability.

[0004] The EMB uses a load sensor to generate a target braking force required by the driver. The EMB equipped with a load sensor can accurately measure the clamping force. However, if the EMB is equipped with a load sensor, the design of the component on which the sensor is mounted becomes complicated and its manufacturing cost increases. In addition, the size of the EMB may inevitably increase due to the sensor installation.

[0005] In order to prevent an increase in the manufacturing cost and size of the EMB, the EMB can be designed to measure the current flowing through the motor that generates the braking force with a current sensor instead of a load sensor, and then measure or estimate the clamping force based on the measured current. However, the method of estimating the clamping force by measuring the current flowing through the motor has a problem because there is a greater error compared with the case of using a load sensor, and thus it is difficult to accurately calculate the initial position, that is, the position where the pressing unit contacts the friction pad. Therefore, it is difficult to ensure the stable braking performance of the vehicle. Summary of the Invention

[0006] In view of the above, the present disclosure provides an electro-mechanical brake that can more accurately calculate the initial position based on two points, thereby achieving the stable braking performance of the vehicle.

[0007] The problems to be solved by the present disclosure are not limited to the above problems, and those skilled in the art will clearly understand other problems not mentioned from the following description.

[0008] According to at least one embodiment, the present disclosure provides an electromechanical brake, including: a brake disc; a friction block configured to face the brake disc and press the brake disc; a pressing unit configured to press the friction block toward the brake disc; a motor that supplies power to the pressing unit to press the friction block; a current sensor configured to measure the intensity (i) of the current flowing through the motor; a position sensor configured to measure the position (d) of the pressing unit; and an initial position calculation unit that calculates at least one of the initial position or the contact point of the pressing unit, wherein the pressing unit is configured to pass through a first check point (C1) and a second check point (C2), a first current (i1) is measured at the first check point (C1), and a second current (i2) greater than the first current is measured at the second check point (C2), and wherein the initial position calculation unit calculates at least one of the initial position or the contact point based on the first current, the first check point, the second current, and the second check point.

[0009] According to another embodiment, the present disclosure provides a method for initializing the control of an electromechanical brake, the electromechanical brake including: a brake disc; a friction block configured to face the brake disc and press the brake disc; a pressing unit configured to press the friction block toward the brake disc; a motor that supplies power to the pressing unit to press the friction block; a current sensor configured to measure the intensity of the current flowing through the motor; a position sensor configured to measure the position of the pressing unit; and an initial position calculation unit that calculates at least one of the initial position or the contact point of the pressing unit, the method including: a step of moving the pressing unit in a direction of a first check point for pressing the friction block until a first current is measured; a step of moving the pressing unit toward the brake disc to a second check point at which a second current is measured, the second current being greater than or equal to a reference current that is greater than the first current; and a step of calculating at least one of the initial position or the contact point based on the first current, the first check point, the second current, and the second check point.

[0010] As described above, an embodiment of the present disclosure provides an electromechanical brake that can more accurately calculate the initial position based on two points, thus achieving stable braking performance of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a cross-sectional view showing an electromechanical brake.

[0012] Figure 2 is a graph showing the position, current, and clamping force of the pressing unit according to time.

[0013] Figure 3 is a graph showing the current and clamping force according to time.

[0014] Figure 4 Shows the distance-current graph for each case with different electro-mechanical brake powers.

[0015] Figure 5 is a distance-current graph for explaining the initial position calculation method according to an embodiment of the present disclosure.

[0016] Figure 6 Shows the distance-current graph of the electro-mechanical brake according to an embodiment of the present disclosure.

[0017] Figure 7 is a flowchart showing a method of controlling the initialization of an electro-mechanical brake according to an embodiment of the present disclosure.

[0018] Figure 8 is a flowchart showing the process of controlling the initialization of an electro-mechanical brake according to the present disclosure.

[0019] Reference numerals:

[0020] 100: Brake disc 110: Friction block

[0021] 120: Pressing unit 130: Motor

[0022] h.p: Initial position c.p: Contact point

[0023] C1: First check point C2: Second check point

[0024] C3: Reference point d1: First distance

[0025] d2: Second distance i1: First current

[0026] i2: Second current P1: First position

[0027] P2: Second position Detailed Description

[0028] Some exemplary embodiments of the present disclosure will be described below with reference to the accompanying drawings. In the following description, like reference numerals preferably designate like elements, although these elements are shown in different drawings. In addition, in the following description of some embodiments, detailed descriptions of known functions and configurations incorporated herein will be omitted for clarity and conciseness.

[0029] In addition, alphanumeric codes in component numbers, such as first, second, i), ii), a), b), etc., are only used for the purpose of distinguishing one component from another, rather than implying or suggesting the substance, instruction, or order of the components. In this specification, when parts "contain" or "include" components, it means that other components are further included, but other components are not excluded, unless there are special instructions to the contrary.

[0030] Figure 1 is a cross-sectional view showing an electromechanical brake.

[0031] Reference Figure 1 , the electromechanical brake according to an embodiment of the present disclosure includes a brake disc 100, friction blocks 110, a pressing unit 120, a motor 130, a current sensor (not shown), a position sensor (not shown), and an initial position calculation unit (not shown).

[0032] The friction blocks 110 are configured to face the brake disc 100 and press the brake disc 100. A pair of friction blocks 110 may be mounted on both sides of the brake disc 100 so as to face each other. At least a part of the friction blocks may be accommodated in the caliper housing 180 or the carrier 190 to guide the friction blocks 110 such that the friction blocks 110 move perpendicular to one side of the brake disc 100. When the piston unit 125 presses the friction blocks 110, the friction blocks 110 may slide toward the brake disc 100, wherein the friction blocks 110 are mounted such that at least a part of the friction blocks is accommodated in the carrier 190.

[0033] The pressing unit 120 is configured to press the friction blocks 110 toward the brake disc 100. The clamping force applied by the pressing unit 120 to the friction blocks 110 is large enough such that the actual displacement of the pressing unit 120 is very small and thus may not be measurable. In the present disclosure, the pressing of the pressing unit 120 toward the brake disc 100 includes the case where the motor 130 rotates in a direction to increase the clamping force applied to the brake disc 100.

[0034] The pressing unit 120 may include at least one of a gear, the pressing unit 120, or the piston unit 125.

[0035] The rotational power generated by the electric motor 130 is transmitted to the pressing unit 120 through one or more gears. The pressing unit 120 translates the friction block 110 toward the brake disc 100. The gears are installed in a gearbox 140 close to the brake disc 100. More specifically, the pressing unit 120 may include a nut unit 123 and a bolt unit 121 installed in a caliper housing 180. When the bolt unit 121 rotates through the gears, it engages with the nut unit 123 to perform a linear motion. A piston unit 125 installed on the front portion of the nut unit 123 and pressed by the nut unit 123 contacts the friction block 110 to press the friction block 110. However, the electro-mechanical brake of the present disclosure is not limited thereto. The electro-mechanical brake of the present disclosure includes various embodiments in which the piston unit 125 is the nut unit 123 itself, or the bolt unit 121 performs a translational motion and the nut unit 123 performs a rotational motion.

[0036] The electric motor 130 supplies power to the pressing unit 120 such that the pressing unit 120 presses the friction block 110. Since a stroke is applied to a pedal of a vehicle, a brake signal or a brake release signal is transmitted to the electric motor 130. The rotational force of the electric motor 130 is controlled in response to the brake signal or the brake release signal. The brake signal or the brake release signal may be generated by a driver's pedal stroke.

[0037] In the present disclosure, the position of the pressing unit 120 refers to the position of an end face of the friction block 110 of the pressing unit 120. In an embodiment of the present disclosure, the position of the pressing unit 120 may refer to the position of the end face of the friction block 110 of the piston unit 125. In the present disclosure, the distance refers to the distance from a starting position h.p (which will be described below) to the position of the pressing unit 120. In the present disclosure, the direction in which the pressing unit 120 is moved toward the brake disc 100 is defined as the (+) direction.

[0038] A position sensor is configured to measure the position of the pressing unit 120. If the position of the pressing unit 120 is determined without considering factors such as wear of the friction block 110, etc., the position of the end face of the friction block 110 having a certain specification produced and facing the brake disc 100 can be roughly estimated.

[0039] Figure 2 is a graph showing the position, current, and clamping force of the pressing unit 120 according to time.

[0040] Figure 3 is a graph showing the current and clamping force according to time.

[0041] Reference Figures 1 to 3, the pressing unit 120 of the electromechanical brake presses the friction block 110 to generate a braking force. Here, the force with which the pressing unit 120 presses the friction block 110 is defined as the clamping force. The clamping force is approximately proportional to the intensity of the current measured by the current sensor, which will be described later.

[0042] Since the pressing unit 120 does not contact and press the friction block 110, the friction block 110 can be spaced apart from the brake disc 100. In this case, no clamping force is generated regardless of the movement of the pressing unit 120.

[0043] The distance at which the pressing unit 120 starts to contact the friction block 110 is called the contact point c.p. In addition, the point at which the pressing unit 120 is spaced a small distance from the contact point c.p in the pressing release direction and no clamping force is generated is called the starting position h.p. According to the material specification of the friction material, the value of this small distance can be about 0.1 mm to 0.3 mm.

[0044] When the pressing unit 120 moves from the contact point c.p toward the brake disc 100, the force with which the friction block 110 presses the brake disc 100 increases. A pair of friction blocks 110 provided on both sides of the brake disc 100 can restrain the rotation of the wheel by pressing both sides of the brake disc 100.

[0045] When the distance of the pressing unit 120 approaches the initial position h.p, the stiffness of the friction block 110 does not play a dominant role in the intensity of the current (i.e., the magnitude of the clamping force) in the distance-current relationship. Therefore, when the distance of the pressing unit 120 approaches the initial position h.p, the distance-current graph is plotted non-linearly. However, as the distance of the pressing unit 120 increases, the stiffness of the friction block 110 becomes the main variable in the magnitude of the clamping force, making the distance-current approach a linear relationship.

[0046] Figure 4 The distance-current graphs in each case of different powers of the electromechanical brake are shown.

[0047] Figure 5 is a distance-current graph for explaining the initial position calculation method according to an embodiment of the present disclosure.

[0048] Reference Figure 4 and 5, when the distance approaches zero (0), the distance and the current have a non-linear relationship. As the distance increases, the distance and the current become closer to a linear relationship. In the present disclosure, the part where the distance is small and the distance and the current have a non-linear relationship is referred to as the non-linear part, while the part with a larger distance is referred to as the linear part. Since the distance and the clamping force are approximately linearly related in the linear part, the clamping force can be estimated relatively accurately using a position sensor. However, it is difficult to estimate the contact point c.p or the initial position h.p between the brake disc 100 and the friction block 110 only using a position sensor. Instead of using a position sensor, a current sensor should be used to detect the contact point c.p or the initial position h.p, which will be described later.

[0049] The current sensor is configured to measure the intensity of the current of the drive motor 130. The intensity of the current measured by the current sensor is approximately proportional to the clamping force. Therefore, the intensity of the current measured by the current sensor can be used to estimate the clamping force of the electromechanical brake. The current sensor may not be newly installed to implement the electromechanical brake of the present disclosure, but the current sensor installed in the motor 130 of the existing electromechanical brake may be used.

[0050] Reference Figure 3 , due to the low resolution of the current sensor and the large noise of the measured current, it is difficult to accurately detect the position of the contact point c.p. For example, if it is determined that the point where the current intensity of 5A is detected is the contact point c.p, when the current intensity as shown in Figure 3 is detected, it is difficult to accurately determine which point is the contact point c.p.

[0051] The position of the pressing unit 120 generated by subtracting a predetermined distance determined by experiment from the position of the pressing unit 120 that detects a predetermined current intensity can be estimated as the contact point c.p. This is to overcome the low accuracy of the current sensor. Hereinafter, in the present disclosure, the above method is referred to as the method using one point.

[0052] When the relationship between the current intensity measured by the current sensor and the clamping force is constant, the method using one point is effective. However, the efficiency of converting the electric power of the drive motor 130 into the clamping force can vary. This may be caused by environmental factors such as impurities mixed between the friction blocks 110 or temperature changes of the friction blocks 110, or wear due to repeated operations or temperature changes of the disc brake.

[0053] Figure 4 Shows the distance-current diagram when the efficiency of converting the electric power used for the drive motor 130 into the clamping force is different.

[0054] Reference Figure 4, when the efficiency of converting the electric power used to drive the motor 130 into the clamping force is different, it may not be possible to calculate the accurate contact point c.p. by the above method. In this case, using the method of a single point may lead to inaccurate results. If the accurate contact point c.p. cannot be calculated, the distance-current graph may also become inaccurate.

[0055] On the other hand, in the electromechanical brake according to an embodiment of the present disclosure, the point that moves a certain distance from a point on the distance-current graph is not determined as the contact point c.p.

[0056] The pressing unit 120 of the present disclosure is configured to pass from the first inspection point C1 where the first current i1 is measured to the second inspection point C2 where the second current i2 is measured. Therefore, the initial position h.p. or the contact point c.p. is calculated based on these two points.

[0057] The initial position calculation unit of the device according to an exemplary embodiment of the present disclosure may be a processor (e.g., a computer, a microprocessor, a CPU, an ASIC, a circuit, a logic circuit, etc.). The initial position calculation unit may be implemented by a non-transitory memory and a processor, where the non-transitory memory stores, for example, programs, software instruction reproduction algorithms, which implement various calculation functions described below when executed, and the processor is configured to execute the programs, software instruction reproduction algorithms, etc. Herein, the memory and the processor may be implemented as separate semiconductor circuits. Alternatively, the memory and the processor may be implemented as a single integrated semiconductor circuit. The processor may embody one or more processors.

[0058] The initial position calculation unit according to an embodiment of the present disclosure calculates at least one of the initial position h.p. or the contact point c.p. of the pressing unit 120. More specifically, the initial position calculation unit calculates the initial position h.p. or the contact point c.p. based on the first current i1, the first inspection point C1, the second current i2, and the second inspection point C2.

[0059] When the position of the pressing unit 120 changes from the first inspection point C1 to the second inspection point C2, the initial position calculation unit according to an embodiment of the present disclosure calculates a reference point C3 based on the change amount of the current, and calculates at least one of the initial position h.p. or the contact point c.p. based on the reference point C3. That is, the reference point is calculated according to the slope of the point (C1, i1) to the point (C2, i2) on the distance-current graph.

[0060] For example, referring to Figure 5 , the initial position calculation unit calculates the reference point C3 that satisfies Equation 1 or Equation 2.

[0061]

Equation 1

[0062]

[0063]

Equation 2

[0064]

[0065] The position of the pressing device at the point where the straight line connecting two points on the distance - current graph intersects the distance axis is regarded as the reference point.

[0066] Calculate at least one of the initial position h.p or the contact point c.p based on the reference point C3. The initial position calculation unit according to an embodiment of the present disclosure calculates the position where the pressing unit 120 moves away from the brake disc 100 by a first distance d1 from the reference point C3 as the initial position h.p or the contact point c.p.

[0067] For example, the initial position h.p or the contact point c.p is calculated by Equation 3.

[0068]

Equation 3

[0069] h.p or c.p = c3 - d1

[0070] Reference Figure 4 and 5 , according to the electro - mechanical brake of an embodiment of the present disclosure, the initial position h.p or the contact point c.p can be accurately calculated even if the efficiency of converting the electric power of the drive motor 130 into the clamping force varies due to repeated operations of the electro - mechanical brake or environmental factors. To calculate the initial position h.p or the contact point c.p more accurately, a pair of points spaced a predetermined distance or more apart from each other can be detected multiple times, and the average slope connecting each pair of points can be used. The initial position calculation unit can be the logic or circuit included in the control unit installed in an existing vehicle, rather than a new component added to the existing vehicle.

[0071] The initial position calculation unit according to an embodiment of the present disclosure calculates the position where the pressing unit 120 moves away from the reference position C3 by a first distance d1 from the brake disc 100 as the initial position h.p or the contact point c.p.

[0072] The first distance d1 can be a value that varies according to the magnitude of the clamping force of the electric power of the drive motor 130 or the temperature of the friction block 110. Therefore, according to an embodiment of the present disclosure, the first distance d1 is determined based on at least one of the efficiency of converting the electric power applied to the motor 130 into the clamping force and the amount of wear of the friction block 110. Thus, the initial position calculation unit according to an embodiment of the present disclosure can accurately calculate at least one of the initial position h.p and the contact point c.p even if the magnitude of the clamping force of the electric power of the motor 130 or the temperature of the friction block 110 changes. However, the present disclosure is not limited thereto, and the first distance d1 can be preset through one or more experiments. The preset first distance d1 can be configured as, for example, a list value that varies according to the above - mentioned efficiency.

[0073] Figure 6 Shows a distance - current diagram of an electromechanical brake according to an embodiment of the present disclosure.

[0074] When comparing Figure 4 and 6 the electromechanical brake according to an embodiment of the present disclosure uses two points on the distance - current diagram to calculate the initial position h.p. Thus, in the electromechanical brake according to an embodiment of the present disclosure, even if the magnitude of the clamping force of the electric power of the drive motor changes, the initial position h.p can be calculated with very high accuracy.

[0075] The first check point is closer to the brake disc than a predetermined first position P1, and the second check point is closer to the brake disc than a predetermined second position P2.

[0076] As shown in the reference figure Figure 4 and 5 when the first check point C1 and the second check point C2 deviate from the non - linear part of the distance - current diagram, it is easy to accurately calculate the initial position h.p or the contact point c.p. The values of the first position P1 and the second position P2 are such that the first check point C1 and the second check point C2 are located in the linear part of the distance - current diagram.

[0077] The first check point C1 and the second check point C2 according to an embodiment of the present disclosure are spaced apart from each other by a predetermined distance. As shown in the reference figure Figure 4 and 5 if the distance between the first check point C1 and the second check point C2 is narrow, especially if the first check point C1 and the second check point C2 are placed close to the non - linear part, the deviation of the calculated initial position h.p may increase depending on the surrounding environment or the efficiency of converting the electric power of the motor into the clamping force. On the contrary, by increasing the distance between the first check point C1 and the second check point C2, the initial position h.p or the contact point c.p can be calculated relatively accurately.

[0078] In the electromechanical brake according to an embodiment of the present disclosure, the position where the pressing unit 120 moves a second distance d2 from the contact point c.p in the pressing release direction is the initial position h.p. As described above, the point where the pressing unit 120 starts to contact the friction block 110 is referred to as the contact point c.p. Further, the point where the pressing unit 120 is separated from the contact point c.p by a second distance d2 to the other side of the friction block 110 and no clamping force is generated is referred to as the initial position h.p. In this case, according to the material specification of the friction material, the value of the second distance d2 may be about 0.1 mm to 0.3 mm. The initial position calculation unit according to an embodiment of the present disclosure may calculate the contact point c.p, thereby calculating the initial position h.p spaced apart from the contact point c.p by a predetermined distance toward the other side of the friction block 110. Conversely, this may calculate the initial position h.p, thereby calculating the contact point c.p spaced apart from the initial position h.p by a predetermined distance toward the friction block 110.

[0079] Here, the first distance d1 and the second distance d2 can be determined experimentally. The experiment can be performed multiple times to more accurately determine the initial position h.p or the contact point c.p.

[0080] The method for initializing the control of the electromechanical brake according to an embodiment of the present disclosure can be executed by the above-described electromechanical brake.

[0081] Figure 7 is a flowchart showing a method for initializing the control of the electromechanical brake according to an embodiment of the present disclosure.

[0082] Reference Figure 7 , the method for initializing the control of the electromechanical brake according to an embodiment of the present disclosure includes at least one of the following steps: Step S700: Input an electromechanical brake control initialization signal; Step S720: Initialize the control of the electromechanical brake; Step S730: Input a braking signal to the motor 130; Step S740: Determine whether the current current is less than the first current i1; Step S750: Determine whether the current current is greater than the second current i2; and Step S760: Terminate the initialization of the electromechanical brake control.

[0083] In step S700, for example, by opening the door, a control initialization signal for reconstructing the distance-current diagram is input to the electromechanical brake. In the case where the electromechanical brake control initialization signal is input, step S720 is executed. Step S720 will be described in detail below.

[0084] In step S730, a braking signal may be generated due to the driver's pedal stroke. When the braking signal is not input to the motor 130 in step S730, step S740 is executed. On the other hand, in the case where the braking signal is input to the motor 130, step S750 is executed.

[0085] In step S740, if the current current is greater than the reference current, the initialization of the electro-mechanical brake control is terminated. On the other hand, when the current current is less than the reference current, the process returns to step S720.

[0086] That is, when the braking signal is input to the motor 130 before reaching the reference current, the second current i2 is the reference current. After the pressing unit 120 moves toward the friction block 110 to reach the reference current, the braking signal can be input. In this case, the current value when the braking signal is input is set as the second reference current. For example, if the brake pedal signal is received before reaching the reference current, the pedal signal is ignored, and the pressing unit 120 moves in the pressing direction until the reference current is reached. If the pedal signal is input when the current intensity passes through the reference current and points to the second current i2 (which is the recommended value), the current when the pedal signal is input is set as the second current i2 and the control initialization is terminated. In addition, after the brake pedal signal reaches the recommended second current i2, the braking signal can be input before completely releasing the braking force generated for initialization. In this case, since the initialization has been completed, the braking force is generated according to the input pedal signal. If the pedal signal is not received after reaching the recommended second current i2, the process will wait for the pedal signal while maintaining the state where the initialization has been terminated.

[0087] Figure 8 is a flowchart showing the process of controlling the initialization of the electro-mechanical brake according to the present disclosure.

[0088] Reference Figure 8 According to step S720 of an embodiment of the present disclosure, it is executed within a predetermined time after the input of the control initialization signal. For example, this is executed within one second after the vehicle door is opened. This is to extend the process of initializing the control of the electro-mechanical brake, thereby preventing the driver from feeling that the vehicle is being braked against their will.

[0089]

[0090] ​Step S723 according to an embodiment of the present disclosure includes: when the position of the pressing unit 120 changes from the first check point C1 to the second check point C2, calculating a reference position C3 based on the change amount of the current; and calculating at least one of the initial position h.p or the contact point c.p based on the reference point.

[0091] For example, the step of calculating at least one of the initial position or the contact point can be expressed as Equation 4 or Equation 5.

[0092]

Equation 4

[0093]

[0094] Or

[0095]

Equation 5

[0096]

[0097] The method may include the step of calculating a reference point C3 that satisfies the above equation and calculating at least one of the initial position or the contact point based on the reference point.

[0098] Step S723 according to an embodiment of the present disclosure may include subtracting a first distance d1 from the reference point C3. Alternatively, an embodiment of the present disclosure may further include performing an experiment to determine the first distance d1.

[0099] Although the exemplary embodiments of the present disclosure are described for illustrative purposes, those skilled in the art will understand that various modifications, additions, and substitutions can be made without departing from the spirit and scope of the present disclosure. Therefore, the exemplary embodiments of the present disclosure have been described for brevity and clarity. The scope of the technical idea of this embodiment is not limited by the illustrations. Therefore, those of ordinary skill in the art will understand that the scope of the present disclosure is not limited by the embodiments described above in detail, but is limited by the technical solutions and their equivalents.

Claims

1. An electromechanical brake, comprising: A brake disc; A friction block configured to face the brake disc and press against the brake disc; A pressing unit configured to press the friction block toward the brake disc; A motor that supplies power to the pressing unit to cause the pressing unit to press the friction block; A current sensor configured to measure the intensity (i) of the current flowing through the motor; A position sensor configured to measure the position (d) of the pressing unit; and An initial position calculation unit that calculates at least one of the initial position of the pressing unit or the contact point, wherein the pressing unit is configured to pass through a first check point (C1) and a second check point (C2), at the first check point (C1) a first current (i1) is measured, and at the second check point (C2) a second current (i2) greater than the first current is measured, and wherein the initial position calculation unit calculates at least one of the initial position or the contact point based on the first current, the first check point, the second current, and the second check point, wherein when the position of the pressing unit changes from the first check point to the second check point, the initial position calculation unit calculates a reference point (C3) based on the change amount of the current, and calculates at least one of the initial position or the contact point based on the reference point, wherein the initial position calculation unit calculates at least one of the initial position or the contact point based on the position where the pressing unit moves away from the brake disc by a first distance (d1) from the reference point.

2. The electromechanical brake according to claim 1, wherein, The first distance is determined based on at least one of the power converted from the electric power applied to the motor into a clamping force or the wear amount of the friction block.

3. The electromechanical brake according to claim 1, wherein, The first check point is closer to the brake disc than a predetermined first position (P1), and the second check point is closer to the brake disc than a predetermined second position (P2).

4. The electromechanical brake according to claim 1, wherein, The first check point and the second check point are spaced apart by a predetermined distance from each other.

5. The electromechanical brake according to claim 1, wherein, When the pressing unit moves from the first check point to the second check point, the pressing unit moves only toward the brake disc.

6. A method for initializing the control of an electromechanical brake, the electromechanical brake comprising: A brake disc; A friction block configured to face the brake disc and press against the brake disc; A pressing unit configured to press the friction block toward the brake disc; A motor that supplies power to the pressing unit to cause the pressing unit to press the friction block; A current sensor configured to measure the intensity of the current flowing through the motor; A position sensor configured to measure the position of the pressing unit; And An initial position calculation unit that calculates at least one of the initial position of the pressing unit or the contact point, the method comprising: Step: The pressing unit moves in a direction for pressing the friction block to a first check point where a first current is measured; Step: The pressing unit moves towards the brake disc to a second check point, at which a second current is measured, the second current being greater than or equal to a reference current, the reference current being greater than the first current; and Step: Calculate at least one of the initial position and the contact point based on the first current, the first check point, the second current and the second check point, wherein the step of calculating at least one of the initial position and the contact point includes: Step: When the position of the pressing unit changes from the first check point to the second check point, calculate a reference point (C3) based on the change in current; and Step: Calculate at least one of the initial position and the contact point based on the reference point, wherein the step of calculating at least one of the initial position or the contact point includes the step of subtracting a first distance (d1) from the reference point (C3).

7. The method according to claim 6, wherein, The method of controlling the initialization of the electromechanical brake is performed within a predetermined time after a control initialization signal is input.

8. The method according to claim 6, wherein, When a braking signal is input to the motor before the reference current is reached, the second current is set to the reference current.

9. The method according to claim 6, wherein When a braking signal is input after the pressing unit moves towards the brake disc and reaches the reference current, the current value at the time when the braking signal is input is set as the second current.

10. The method according to claim 8, wherein, The braking signal is generated by the driver's pedal stroke.

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