KR102643647B1 - Apparatus and method for controlling electro mechanical brake of vehicle - Google Patents

Abstract

The present invention relates to an electronic brake control device for a vehicle, comprising: a pedal sensor unit that detects a stroke of the brake pedal; a control unit that independently controls the front-wheel braking unit and the rear-wheel braking unit of the vehicle based on the displacement of the brake pedal detected through the pedal sensor unit; and the rear wheel braking unit implemented with an electro mechanical brake (EMB).

Description

Electronic brake control device and method for vehicle {APPARATUS AND METHOD FOR CONTROLLING ELECTRO MECHANICAL BRAKE OF VEHICLE}

The present invention relates to an electronic brake control device and method for a vehicle, and more specifically, to an electronic brake control device and method for a vehicle that allows controlling the electronic brake (EMB: Electro Mechanical Brake) applied to the rear wheels of the vehicle. It's about.

In general, electronic brake (EMB) is a system in which all hydraulic lines of existing vehicles are removed, and all braking is controlled by electrical and electronic devices.

In other words, electronic brakes (EMB) convert the force with which the driver presses the brake pedal into an electrical signal instead of the hydraulic brake system used in vehicles. For example, when the driver steps on the pedal, the simulator attached to the pedal converts this into an electrical signal and transmits it to the electronic control unit (ECU). The electronic control unit (ECU) calculates the vehicle status and braking force and controls the electric caliper. am.

Therefore, the electronic brake (EMB) integrates control of the existing ABS, TCS, BAS, and ESP (Electronic Stability Program) functions and is capable of controlling the vehicle's posture in any situation. When the electronic brake (EMB) system is applied, the vehicle As many of the parts of existing hydraulic lines, such as master cylinders and boosters, are no longer needed, the number of braking-related parts is greatly reduced. This simplifies the structure of the brake system, which has the advantage of greatly increasing flexibility when designing cars.

In addition, the electronic brake (EMB) does not require time for hydraulic pressure to be transmitted and enables active control of vehicle braking force, so it has the advantage of shorter braking distance than existing brake systems. Not only does the driver's safety improve, but electronic braking makes it easier to use the brake pedal and does not generate any vibration or braking noise.

However, the electronic brake (EMB) requires individual motor and ECU configuration for each caliper, which is a major cause of increase in vehicle price.

Moreover, the electronic brake (EMB), like the electronic parking brake (EPB), is not only involved in parking braking, but must act as a permanent braking device, so it requires high durability specifications (i.e., high operating frequency durability specifications), thereby reducing the risk of damage to the brushes. There is a problem in that a brushless BLDC (Brushless DC) motor must be used instead of a direct current (DC) motor, which has lower durability specifications (i.e., operating frequency durability specifications), and as a result, the specifications of the ECU for controlling the BLDC motor are also increased, thereby reducing the unit cost of the vehicle. There was a problem that caused it to rise even further.

Therefore, in order to maintain the function of the electromagnetic brake (EMB) but lower the unit cost of the vehicle, the durability specifications (i.e., operation count durability specifications) of the motor required for braking of the electromagnetic brake (EMB) can be lowered. There is a need for technology that allows this somewhat inferior, low-cost direct current (DC) motor to be applied to an electronic brake (EMB).

The background technology of the present invention is disclosed in Republic of Korea Patent No. 10-1294126 (registered on August 1, 2013, regenerative braking system).

According to one aspect of the present invention, the present invention was created to solve the above problems, and provides electronic brake control of the vehicle to control the electronic brake (EMB: Electro Mechanical Brake) applied to the rear wheels of the vehicle. The purpose is to provide a device and method.

An electronic brake control device for a vehicle according to one aspect of the present invention includes a pedal sensor unit that detects a stroke of the brake pedal; a control unit that independently controls the front-wheel braking unit and the rear-wheel braking unit of the vehicle based on the displacement of the brake pedal detected through the pedal sensor unit; and the rear wheel braking unit implemented with an electro mechanical brake (EMB).

In the present invention, the rear wheel braking unit is characterized in that it includes an invalid stroke section in which no actual braking force is generated and an actual braking section in which actual braking force is generated, according to the structural characteristics of the electronic brake (EMB).

In the present invention, when controlling the electronic brake (EMB) of the rear wheel brake unit, the control unit controls the electronic brake (EMB) at a point later than the braking start point (S) of the front wheel brake unit, based on the pedal stroke axis. It is characterized in that it initiates the starting point (B) of the actual braking section that generates the actual braking force.

In the present invention, when controlling the electronic brake (EMB) of the rear wheel braking unit, the control unit, based on the pedal stroke axis, operates at a point later than or equal to the braking start point (S) of the front wheel braking unit. Characterized in that it initiates the starting point of the invalid stroke section of EMB).

In the present invention, when controlling the electronic brake (EMB) of the rear wheel brake unit, the control unit controls the electronic brake (EMB) at the same point as the braking start point (S) of the front wheel brake unit, based on the pedal stroke axis. When starting the starting point of the invalid stroke section, set the holding section between the starting point (B) of the actual braking section where the electronic brake (EMB) generates actual braking force and the ending point (A) of the invalid stroke section. It is characterized in that the rear wheel brake unit does not brake.

In the present invention, in order to compensate for the holding section, the control unit determines that the slope from the starting point (B) of the actual braking section to the point (E) where the pedal stroke corresponding to the maximum braking force is input is that of the invalid stroke section. The rear wheel braking force is increased to a greater extent than the slope from the end point (A) to the point (E) where the pedal stroke corresponding to the maximum braking force is input.

In the present invention, when controlling the electronic brake (EMB) of the rear wheel brake, the control unit sets an operation start point of the rear wheel brake, which is later than the braking start point (S) of the front wheel brake, based on the pedal stroke axis. When starting operation of the electronic brake (EMB) at (C), between the rear wheel braking unit operation start point (C) and the starting point (B) of the actual braking section where the electronic brake (EMB) generates actual braking force It is characterized by control including an invalid stroke section.

In the present invention, the control unit performs actual braking to compensate for the section in which the electronic brake (EMB) does not operate from the braking start point (S) of the front wheel brake unit to the operation start point (C) of the rear wheel brake unit. The slope from the starting point of the section (B) to the point (E) where the pedal stroke corresponding to the maximum braking force is input is the point where the pedal stroke corresponding to the maximum braking force is input from the braking start point (S) of the front wheel brake unit. It is characterized by increasing the rear wheel braking force to a greater extent than the slope up to (E).

A method of controlling the electronic brake of a vehicle according to another aspect of the present invention includes the steps of a pedal sensor unit detecting a stroke of the brake pedal; and a step of the control unit independently controlling the front wheel braking unit and the rear wheel braking unit implemented as an electronic brake (EMB) of the vehicle based on the displacement of the brake pedal detected through the pedal sensor unit.

In the present invention, the rear wheel braking unit is characterized in that it includes an invalid stroke section in which no actual braking force is generated and an actual braking section in which actual braking force is generated, according to the structural characteristics of the electronic brake (EMB).

In the present invention, when controlling the electronic brake (EMB) of the rear wheel brake unit, the control unit controls the electronic brake (EMB) at a later point than the braking start point (S) of the front wheel brake unit, based on the pedal stroke axis. It is characterized in that it initiates the starting point (B) of the actual braking section that generates the actual braking force.

In the present invention, when controlling the electronic brake (EMB) of the rear wheel brake unit, the control unit operates the electronic brake (EMB) at a point later than or equal to the braking start point (S) of the front wheel brake unit, based on the pedal stroke axis. Characterized in that it initiates the starting point of the invalid stroke section of EMB).

In the present invention, when controlling the electronic brake (EMB) of the rear wheel brake unit, the control unit controls the electronic brake (EMB) at the same point as the braking start point (S) of the front wheel brake unit, based on the pedal stroke axis. When starting the starting point of the invalid stroke section, set the holding section between the starting point (B) of the actual braking section where the electronic brake (EMB) generates actual braking force and the ending point (A) of the invalid stroke section. It is characterized in that the rear wheel brake unit does not brake.

In the present invention, in order to compensate for the holding section, the control unit determines that the slope from the starting point (B) of the actual braking section to the point (E) where the pedal stroke corresponding to the maximum braking force is input is that of the invalid stroke section. The rear wheel braking force is increased to a greater extent than the slope from the end point (A) to the point (E) where the pedal stroke corresponding to the maximum braking force is input.

In the present invention, when controlling the electronic brake (EMB) of the rear wheel braking unit, the control unit sets an operation start point of the rear wheel braking unit that is later than the braking start point (S) of the front wheel braking unit, based on the pedal stroke axis. When starting operation of the electronic brake (EMB) at (C), between the rear wheel braking unit operation start point (C) and the starting point (B) of the actual braking section where the electronic brake (EMB) generates actual braking force It is characterized by control including an invalid stroke section.

In the present invention, in order to compensate for the section in which the electronic brake (EMB) does not operate from the braking start point (S) of the front wheel brake unit to the operation start point (C) of the rear wheel brake unit, the control unit performs actual braking. The slope from the starting point of the section (B) to the point (E) where the pedal stroke corresponding to the maximum braking force is input is the point where the pedal stroke corresponding to the maximum braking force is input from the braking start point (S) of the front wheel brake unit. It is characterized by increasing the rear wheel braking force to a greater extent than the slope up to (E).

According to one aspect of the present invention, the present invention enables control of an electronic brake (EMB) applied to the rear wheels of a vehicle. The present invention maintains the function of the electromagnetic brake (EMB), but lowers the durability specification (i.e., the number of operation durability specifications) of the motor required for braking of the electromagnetic brake (EMB). Accordingly, the present invention allows a low-cost direct current (DC) motor with somewhat poor durability specifications to be applied to an electronic brake (EMB).

1 is an exemplary diagram showing the schematic configuration of an electronic brake control device for a vehicle according to an embodiment of the present invention.
Figure 2 is an example diagram showing a relationship graph between pedal stroke and front-wheel braking force and rear-wheel braking force during braking according to a conventional brake control method.
Figure 3 is an example diagram showing a relationship graph between pedal stroke and front-wheel braking force and rear-wheel braking force during braking according to the brake control method according to an embodiment of the present invention.
Figure 4 is a flowchart illustrating a method for controlling the electronic brake of a vehicle according to the first embodiment of the present invention.
Figure 5 is an example diagram showing an operation graph according to the electronic brake control method of a vehicle according to the first embodiment of Figure 4.
Figure 6 is a flowchart illustrating a method for controlling the electronic brake of a vehicle according to a second embodiment of the present invention.
FIG. 7 is an example diagram showing an operation graph according to the electronic brake control method of a vehicle according to the second embodiment of FIG. 6.

Hereinafter, an embodiment of an electronic brake control device and method for a vehicle according to the present invention will be described with reference to the attached drawings.

In this process, the thickness of lines or sizes of components shown in the drawing may be exaggerated for clarity and convenience of explanation. In addition, the terms described below are terms defined in consideration of functions in the present invention, and may vary depending on the intention or custom of the user or operator. Therefore, definitions of these terms should be made based on the content throughout this specification.

1 is an exemplary diagram showing the schematic configuration of an electronic brake control device for a vehicle according to an embodiment of the present invention.

As shown in FIG. 1, the electronic brake control device of a vehicle according to this embodiment includes a pedal sensor unit 110, a control unit 120, a front wheel braking unit 130, and a rear wheel braking unit 140. .

The pedal sensor unit 110 includes a stroke sensor.

The pedal sensor unit 110 outputs an electrical signal corresponding to the displacement of the brake pedal. For example, when the driver steps on the brake pedal, the stroke sensor detects the stroke of the brake pedal and transmits it to the control unit 120. do.

The control unit 120 detects the stroke distance (or displacement) of the brake pedal through the pedal sensor unit 110, and operates the front wheel brake unit 130 and the rear wheel based on the stroke distance (or displacement) of the brake pedal. Each braking unit 140 is controlled independently.

Both the front wheel braking unit 130 and the rear wheel braking unit 140 may be implemented as electronic brakes (EMB), or only the rear wheel braking unit 140 may be implemented as an electronic brake (EMB), and the front wheel braking unit 130 may be implemented as an electronic brake (EMB). can be implemented with an existing hydraulic brake system. However, in the following embodiment, for convenience of explanation, it is assumed that only the rear wheel braking unit 140 is implemented as an electronic brake (EMB).

As already mentioned above, the electronic brake (EMB) is a main driving device and must be operated frequently while driving, so it requires much higher operation durability specifications (i.e., operation count durability specifications) than the existing electronic parking brake (EPB).

This is because the existing general braking force generation simultaneously increases the total braking force (i.e., front-wheel braking amount, rear-wheel braking amount) according to the pedal stroke (i.e., the amount of pedal the driver presses), as shown in FIG. 2, so rear-wheel braking The electronic brake (EMB) used in the eastern part 140 also requires the same operation durability specifications (i.e., operation count durability specifications) as the existing hydraulic brake system used in the front wheel braking unit 130.

Therefore, the electromagnetic brake (EMB) can be implemented even using a direct current (DC) motor that is relatively inexpensive, but in order to satisfy the operation durability specification (i.e., operation number durability specification), a BLDC motor was previously applied. This has become a factor in increasing the manufacturing cost of vehicles.

Meanwhile, referring to FIG. 2, even if the total braking force (i.e., front-wheel braking force, rear-wheel braking force) increases simultaneously in response to the pedal stroke (i.e., the amount of pedal the driver presses), the rear-wheel braking force has a relatively lower braking force than the front-wheel braking force. You can see that it works within the range. This is because the vehicle's load is moved forward during normal braking, so the front wheel braking force (or front wheel braking amount) requires a higher braking force than the rear wheel braking force (or rear wheel braking amount).

Meanwhile, Figure 3 is an exemplary diagram shown to explain changes in the amount of front-wheel braking and rear-wheel braking when applying the electronic brake control method of a vehicle according to an embodiment of the present invention (i.e., pedal during braking according to this embodiment) This is a graph showing the relationship between stroke and front-wheel braking force and rear-wheel braking force).

First, when compared with the graph showing the relationship between the pedal stroke and braking force during braking according to the prior art as shown in FIG. 2 (see FIG. 2), referring to (a) of FIG. 3, the pedal stroke axis (i.e. It can be seen that the intervention point (A) of the rear wheel braking unit 140 is formed at a later point than the intervention point of the front wheel braking unit 130 based on the x-axis).

For reference, looking at statistics related to braking, it is known that of the total number of braking occurrences, sudden braking (e.g., braking equivalent to 1.0 g) occurs in only about 10% of cases, and simple braking of less than 0.3 g is known to occur in about 90%. there is.

Here, g is the gravitational acceleration and the maximum braking force is equivalent to 1.0g.

Therefore, assuming that the point (A) at which the rear wheel braking unit 140 begins to engage in Figure 3 (a) is the point corresponding to 0.3g, a simple braking force of less than 0.3g corresponds to about 90% of the total number of braking occurrences. When braking, the rear wheel brake unit 140 does not need to operate, that is, the intervention point of the rear wheel brake unit 140 is adjusted to be later than the intervention point of the front wheel brake unit 130, as shown in (a) of FIG. 3. By doing so, it can be seen that the operation durability specification (i.e., operation number durability specification) required for the rear wheel brake unit 140 can be reduced.

Accordingly, if the point (A) at which the rear wheel braking unit 140 begins to intervene is set to a point corresponding to 0.25g, which is less than 0.3g, the rear wheel braking unit 140 operates more than the point corresponding to 0.3g. Even if the number of endurance times is slightly increased, it can be reduced by at least close to 80% compared to the existing operation endurance specifications (i.e., operation count endurance specifications) (see FIG. 2). As described above, when the operation durability specification (i.e., operation number durability specification) required for the rear wheel brake unit 140 is reduced, a direct current (DC) motor that is cheaper than the operation durability specification (i.e., operation number durability specification) is applied. It becomes possible to design an electronic brake (EMB) that operates.

Meanwhile, Figure 3 (a) shows a graph when the front wheel braking unit 130 uses a general vacuum booster (i.e., hydraulic brake) that operates passively, and the front wheel braking force is the electronic brake (EMB) and Since active control is otherwise impossible, it can be seen that the braking force graph corresponding to the total braking amount is slightly bent (i.e., the degree of braking force increase) at the point A where the rear wheel brake unit 140 intervenes. Because it is not in the same section, drivers do not actually feel much inconvenience.

If an active braking system such as an electric booster is applied to the front wheel braking unit 130, control as shown in (b) of FIG. 3 is possible without even the slight difference as described above.

In both cases such as (a) and (b) of FIG. 3, in order to ensure that the proportion of the rear wheel braking force among the total braking force in the maximum braking force section does not differ from that of the existing brake system, the rear wheel braking force is adjusted as the point at which the rear wheel braking force is intervened is delayed. The lift slope (i.e. slope relative to pedal stroke) must be higher than that of a conventional (see Figure 2) brake system. However, the upward slope of the rear wheel braking force does not necessarily have to be increased.

A specific example of controlling the electronic brake of a vehicle corresponding to the graph shown in FIG. 3 will be described with reference to FIGS. 4 to 7.

FIG. 4 is a flowchart for explaining a method of controlling the electronic brake of a vehicle according to the first embodiment of the present invention, and FIG. 5 is an operation graph according to the method of controlling the electronic brake of a vehicle according to the first embodiment of the present invention. This is an example showing.

Referring to FIG. 4, the control unit 120 checks whether the pedal stroke is greater than the designated invalid end point A (S101).

Here, the invalid end point (A) refers to the invalid section (i.e., the section in which braking does not start even when the brake pedal is pressed) from the time the user starts to press the brake pedal until the actual braking begins, due to the physical (structural) characteristics of the brake system. ) exists, and means the point where the invalid section ends and actual braking begins when the brake pedal is pressed more deeply (i.e., the invalid end point (A), or the invalid stroke end point (A)).

As a result of the check (S101), if the pedal stroke is not greater than the designated invalid end point (A) (No in S101), the control unit 120 controls the demand until the designated invalid end point (A) corresponding to the pedal stroke is reached. The rear wheel drive unit 140 is operated by (demand)1 (S102).

At this time, even if the rear wheel drive unit 140 is operated up to the designated invalid end point A, actual braking by the rear wheel drive unit 140 does not occur. However, the reason for operating the rear wheel drive unit 140 up to the designated invalid end point (A) is to improve the responsiveness of the rear wheel drive unit 140 in case of a sudden transition to sudden braking.

Additionally, the control unit 120 checks whether the pedal stroke is greater than the designated invalid end point (A) (example in S101) and less than the designated rear wheel braking force start point (B) (S103).

As a result of the check (S103), if the pedal stroke is greater than the designated invalid end point (A) (example of S101) and less than the designated rear wheel braking force start point (B) (S104), that is, the pedal stroke is designated invalid end point Even if the input continues through point A to the rear wheel braking force start point B, the control unit 120 controls the rear wheel drive unit 140 to hold (maintain) the rear wheel drive unit 140 without braking (S104).

And if the pedal stroke is greater than the designated rear wheel braking force start point (B) (No in S103), that is, if the pedal stroke continues to be input after passing the designated rear wheel braking force start point (B), the rear wheel brake according to demand 2 Start braking (S105).

As described above, in the first embodiment of the present invention, the control unit 120 can control the rear wheel braking unit 140 by dividing it into three sections. That is, the first section for operating the rear wheel drive unit 140 from the point (S) where the input of the pedal stroke starts (i.e., the start of braking) to the invalid end point (A), the actual rear wheel braking force from the invalid end point (A) A second section for operating the rear wheel drive unit 140 up to the starting point (B), from the point (B) where the actual rear wheel braking force starts to the point where the pedal stroke corresponding to the maximum braking force (e.g. 1g) is input (E ) can be controlled by dividing it into a third section that operates the rear wheel drive unit 140.

for example The rear wheel braking force of the third section can be controlled.

For reference, referring to FIG. 5, in order to compensate for the holding section (A to B), the control unit 120 sets a ratio higher than the ratio of “rear wheel demand/pedal stroke” (i.e., slope indicated by a dotted line) of the existing specification. is controlled to increase the degree of increase in braking force (i.e., slope indicated by a solid line) by the rear wheel brake unit 140.

For example, assuming that up to 15 mm of pedal stroke corresponds to an invalid stroke, that the required clamping force of the brake unit 140 corresponding to 1 g is 10 kN, and that the pedal stroke at that time is 60 mm, the start of rear wheel braking force intervention is delayed by 0.3 g, and 0.3 g Assuming that the pedal stroke corresponding to the deceleration point is 35mm, in the existing brake system, the average rear wheel braking force increase rate compared to the pedal stroke would be “10kN / (60-15)mm = 0.22kN/mm”, but in this embodiment, in the present invention, Since the increase in rear wheel braking force is held until the pedal stroke is 35mm, the rate of increase in braking force in the subsequent section is “10kN / (60-35)mm = 0.4kN/mm”. This is expressed as a value multiplied by a certain constant compared to the existing control method.

Meanwhile, the front wheel drive unit 130 applies front wheel braking force in response to the input of the pedal stroke from the moment the pedal stroke is input, that is, from the braking start point (S), in response to the specified slope (e.g., path ①, path ②). can be increased. For example, in route ①, when applying a front-wheel braking device (e.g. EMB) capable of active control, the front-wheel braking force is increased to a steeper slope compared to before in response to the input of the pedal stroke until the actual rear-wheel braking section begins. When rear wheel braking actually begins, you can adjust it to increase the slope to a more gentle slope than before. And path ② can increase front wheel braking force in response to the input of the pedal stroke regardless of whether or not rear wheel braking actually starts when applying a general braking device such as a conventional vacuum booster that cannot be actively controlled.

FIG. 6 is a flowchart for explaining a method of controlling the electronic brake of a vehicle according to a second embodiment of the present invention, and FIG. 7 is an operation graph according to the method of controlling the electronic brake of a vehicle according to the second embodiment of the present invention. This is an example showing.

Referring to FIG. 6, the control unit 120 checks whether the pedal stroke is greater than the designated rear-wheel drive unit operation start point (C) (S201).

For example, compared to FIG. 5, in the first embodiment of the present invention, when the pedal stroke is input, the front wheel drive unit 130 and the rear wheel drive unit 140 start operating simultaneously, but in the second embodiment of the present invention, the pedal stroke is input. In this case, even if the front wheel drive unit 130 starts operating, the rear wheel drive unit 140 does not start operating until the pedal stroke input reaches the designated rear wheel braking operation start point (C).

Accordingly, the control unit 120 starts operation of the rear wheel brake unit 140 according to demand 1 when the pedal stroke is greater than the designated rear wheel brake operation start point (C) (S202). That is, when the pedal stroke passes the designated rear-wheel brake operation start point C, the rear-wheel brake unit 140 starts operating in response to the pedal stroke input.

Meanwhile, even if the rear wheel drive unit 140 starts operating at the rear wheel brake operation start point (C), due to physical (structural) characteristics, an invalid section (or invalid stroke section, that is, a section in which braking does not start even when the brake pedal is pressed) ) and reaches the point where actual braking begins (i.e., the rear-wheel braking force start point (B)), actual rear-wheel braking begins.

Therefore, although not shown in the drawing, the invalid end point (A) (or invalid stroke end point (A)) may be located between the rear wheel brake operation start point (C) and the rear wheel braking force start point (B). You can.

In addition, the control unit 120 starts rear-wheel braking by demand 2 when the pedal stroke passes the designated rear-wheel braking operation start point (C) and continues to be input to the rear-wheel braking force start point (B) (example of S203). (S204).

As described above, in the second embodiment of the present invention, the control unit 120 can control the rear wheel braking unit 140 by dividing it into three sections. That is, the first section in which the rear-wheel drive unit 140 is not operated from the point (S) where the input of the pedal stroke begins (i.e., the start of front-wheel braking) until the rear-wheel brake operation start point (C), the rear-wheel brake operation start point A second section (i.e., a section including an invalid section) for operating the rear-wheel drive unit 140 from (C) to the point (B) where the actual rear-wheel braking force starts, up to a maximum from the point (B) where the actual rear-wheel braking force starts. It can be controlled by dividing the rear wheel drive unit 140 into a third section in which the rear wheel drive unit 140 is operated up to the point (E) at which the pedal stroke corresponding to the braking force (e.g., 1g) is input.

for example The rear wheel braking force of the second section can be controlled.

also The rear wheel braking force of the third section can be controlled.

As described above, in the second embodiment of the present invention, even if a pedal stroke occurs, the invalid stroke section of the rear wheel brake unit 140 (invalid end after braking start (A) in FIG. 5) is demonstrated by demonstrating the rear wheel brake operation start point (C). Ensure that the number of operations in the section up to is minimized.

In other words, in the first embodiment of the present invention, the rear wheel braking unit 140 is operated in the invalid stroke section (the section from the start of braking to the invalid end (A) in FIG. 5) at the same time as the pedal stroke occurs. Even though the operation of the section corresponds to a no-load condition, it had the disadvantage of having to drive the motor every time it was operated. However, the second embodiment of the present invention has the advantage of delaying the operation of the rear wheel braking unit 140, that is, limiting even basic motor operation until a certain deceleration speed (e.g., 0.2g).

For example, in the second embodiment of the present invention, assuming that the rear-wheel braking force is added from 0.3g and the rear-wheel braking unit 140 starts operating (i.e., the invalid stroke section starts operating) from 0.2g, the braking force is 0.2g or less. In the required deceleration condition of , the motor (actuator) of the rear wheel brake unit 140 is not operated at all, thereby preventing the motor's durability specification (i.e., operation count durability specification) from being reduced.

For reference, referring to FIG. 7, in order to compensate for the section from the start of the pedal stroke input (i.e., start of front wheel braking) to the start of actual rear wheel braking force, the control unit 120 adjusts the “rear wheel demand/pedal stroke” of the existing specification. The degree of increase in braking force by the rear wheel brake unit 140 (i.e., the slope indicated by a solid line) is increased by controlling at a rate higher than the ratio (i.e., the slope indicated by a dotted line).

Meanwhile, the front wheel drive unit 130 applies front wheel braking force in response to the input of the pedal stroke from the moment the pedal stroke is input, that is, from the braking start point (S), in response to the specified slope (e.g., path ①, path ②). can be increased. For example, in route ①, when applying a front-wheel braking device (e.g. EMB) capable of active control, the front-wheel braking force is increased to a steeper slope compared to before in response to the input of the pedal stroke until the actual rear-wheel braking section begins. When rear wheel braking actually begins, you can adjust it to increase the slope to a more gentle slope than before. And path ② can increase front wheel braking force in response to the input of the pedal stroke regardless of whether or not rear wheel braking actually starts when applying a general braking device such as a conventional vacuum booster that cannot be actively controlled.

As described above, in this embodiment, the rear wheel braking unit 140 can be freely actively controlled by applying the electronic brake (EMB) to the rear wheels, and environmental vehicles (e.g., EV, HEV, FCEV, etc.) that perform front wheel regenerative braking and Taking advantage of the fact that in general vehicles, braking is performed only on the front wheels in low deceleration ranges (e.g., less than 0.3g) without any major problems, only front-wheel braking force is generated in low deceleration ranges, and only when exceeding that range, rear wheels are applied. By controlling the generation of braking force, it is possible to lower the durability specifications (i.e., operation count durability specifications) of the motor to be applied to the rear electronic brake (EMB), which has the effect of allowing the use of inexpensive direct current (DC) motors instead of BLDC motors.

In addition, when applying the rear electronic brake (EMB), the hydraulic line on the rear wheel is no longer needed, and the effect of reducing the amount of fluid required from the perspective of the hydraulic braking system can be expected. Therefore, braking only with the front wheels in the low deceleration range does not reduce the braking force, but rather uses the reduction in the amount of liquid required to reduce the diameter of the front wheel master cylinder piston, thereby increasing hydraulic power (i.e., increasing the cross-sectional area ratio). As the power ratio increases and the power ratio increases due to the cross-sectional area ratio, the required piston stroke becomes longer. However, since the original amount of liquid required is less than that of a general vehicle, even if it is longer, the stroke is the same as that of a general vehicle or it is still possible to design with a short stroke (only for the front wheels) It is possible to prevent a decrease in braking torque in the braking section.

In other words, in this embodiment, the hydraulic power of the front-wheel hydraulic braking system can be increased by reducing the amount of liquid required for the hydraulic braking system as the rear wheel electronic brake (EMB) is applied, and also, by utilizing the feature of increasing the hydraulic power as described above, In the low deceleration section, braking can be performed only on the front wheels without braking by the rear electronic brake (EMB), so it has lower durability specifications (i.e., operation count durability specifications) compared to BLDC motors, but uses a cheaper direct current (DC) motor. It has the effect of enabling rear-wheel electronic brake (EMB) to be implemented.

As described above, in this embodiment, by applying the electronic brake (EMB) to the rear wheel, the existing rear wheel hydraulic line is deleted and the amount of hydraulic braking fluid required is reduced, thereby improving the braking feel. Additionally, it is possible to reduce the specifications of the front wheel hydraulic system and rear wheel There are improvements in the torque vectoring function, SCC (Smart Cruise Control) function, and HAS (Hill Start Assist) function by the electronic brake (EMB), and the unit cost of the electromagnetic brake (EMB) is reduced, making the rear wheel electromagnetic brake (EMB) more effective. It has the effect of enabling mass production.

As described above, the present invention has been described with reference to the embodiments shown in the drawings, but these are merely illustrative, and various modifications and equivalent embodiments can be made by those skilled in the art. You will understand the point. Therefore, the scope of technical protection of the present invention should be determined by the scope of the patent claims below. Implementations described herein may also be implemented as, for example, a method or process, device, software program, data stream, or signal. Although discussed only in the context of a single form of implementation (eg, only as a method), implementations of the features discussed may also be implemented in other forms (eg, devices or programs). The device may be implemented with appropriate hardware, software, firmware, etc. The method may be implemented in a device such as a processor, which generally refers to a processing device that includes a computer, microprocessor, integrated circuit, or programmable logic device. Processors also include communication devices such as computers, cell phones, portable/personal digital assistants (“PDAs”) and other devices that facilitate communication of information between end-users.

110: pedal sensor unit 120: control unit
130: front wheel braking unit 140: rear wheel braking unit

Claims (16)

A pedal sensor unit that detects the stroke of the brake pedal;
a control unit that independently controls the front-wheel braking unit and the rear-wheel braking unit of the vehicle based on the displacement of the brake pedal detected through the pedal sensor unit; and
Including the rear wheel braking unit implemented with an electro mechanical brake (EMB),
The control unit,
When controlling the electronic brake (EMB) of the rear wheel braking unit,
Based on the pedal stroke axis,
When the start point of the invalid stroke section of the electronic brake (EMB) starts at the same point as the braking start point (S) of the front wheel brake unit,
Characterized in that the electronic brake (EMB) does not brake the rear wheel brake unit by setting a holding section between the starting point (B) of the actual braking section where the actual braking force is generated and the ending point (A) of the invalid stroke section. A vehicle's electronic brake control device.
The method of claim 1, wherein the rear wheel braking unit,
Depending on the structural characteristics of the electronic brake (EMB),
An invalid stroke section in which no actual braking force is generated, and
An electronic brake control device for a vehicle, characterized in that it includes an actual braking section in which actual braking force is generated.
The method of claim 1, wherein the control unit:
When controlling the electronic brake (EMB) of the rear wheel braking unit,
Based on the pedal stroke axis,
An electronic brake control device for a vehicle, characterized in that the start point (B) of the actual braking section in which the electronic brake (EMB) generates actual braking force is started at a later point than the braking start point (S) of the front wheel brake unit. .
The method of claim 3, wherein the control unit:
When controlling the electronic brake (EMB) of the rear wheel braking unit,
Based on the pedal stroke axis,
An electronic brake control device for a vehicle, characterized in that the start point of the invalid stroke section of the electronic brake (EMB) is started later than or the same as the braking start point (S) of the front wheel brake unit.
delete The method of claim 1, wherein the control unit:
In order to compensate for the holding section,
The slope from the starting point (B) of the actual braking section to the point (E) where the pedal stroke corresponding to the maximum braking force is input is the slope from the ending point (A) of the invalid stroke section to the point where the pedal stroke corresponding to the maximum braking force is input. An electronic brake control device for a vehicle, characterized in that the rear wheel braking force is increased to a greater extent than the slope to point E.
The method of claim 4, wherein the control unit:
When controlling the electronic brake (EMB) of the rear wheel braking unit,
Based on the pedal stroke axis,
When the electronic brake (EMB) starts operating at the rear-wheel brake operation start point (C), which is later than the braking start point (S) of the front-wheel brake,
The electronic brake system of the vehicle is characterized in that it is controlled to include an invalid stroke section between the rear wheel brake operation start point (C) and the start point (B) of the actual braking section where the electronic brake (EMB) generates actual braking force. Brake control unit.
The method of claim 7, wherein the control unit:
In order to compensate for the section in which the electronic brake (EMB) does not operate from the braking start point (S) of the front wheel brake unit to the operation start point (C) of the rear wheel brake unit,
The slope from the starting point (B) of the actual braking section to the point (E) at which the pedal stroke corresponding to the maximum braking force is input is the slope at which the pedal stroke corresponding to the maximum braking force is input from the braking start point (S) of the front wheel brake unit. An electronic brake control device for a vehicle, characterized in that it increases the rear wheel braking force to a greater extent than the slope to the point (E).
A pedal sensor unit detecting a stroke of the brake pedal; and
A step where the control unit independently controls the front wheel braking unit and the rear wheel braking unit implemented by an electronic brake (EMB) of the vehicle based on the displacement of the brake pedal detected through the pedal sensor unit,
When controlling the electronic brake (EMB) of the rear wheel braking unit,
The control unit,
Based on the pedal stroke axis,
When the start point of the invalid stroke section of the electronic brake (EMB) starts at the same point as the braking start point (S) of the front wheel brake unit,
Characterized in that the electronic brake (EMB) does not brake the rear wheel brake unit by setting a holding section between the starting point (B) of the actual braking section where the actual braking force is generated and the ending point (A) of the invalid stroke section. A method of controlling the electronic brake of a vehicle.
The method of claim 9, wherein the rear wheel braking unit,
Depending on the structural characteristics of the electronic brake (EMB),
An invalid stroke section in which no actual braking force is generated, and
A method of controlling electronic brakes for a vehicle, comprising an actual braking section in which actual braking force is generated.
The method of claim 9, wherein when controlling the electronic brake (EMB) of the rear wheel braking unit,
The control unit,
Based on the pedal stroke axis,
An electronic brake control method for a vehicle, characterized in that the start point (B) of the actual braking section in which the electronic brake (EMB) generates actual braking force is initiated at a later point than the braking start point (S) of the front wheel brake unit. .
The method of claim 11, wherein when controlling the electronic brake (EMB) of the rear wheel braking unit,
The control unit,
Based on the pedal stroke axis,
An electronic brake control method for a vehicle, characterized in that starting the start point of the invalid stroke section of the electronic brake (EMB) at a point later than or equal to the braking start point (S) of the front wheel brake unit.
delete The method of claim 9, to compensate for the holding section,
The control unit,
The slope from the starting point (B) of the actual braking section to the point (E) where the pedal stroke corresponding to the maximum braking force is input is the slope from the ending point (A) of the invalid stroke section to the point where the pedal stroke corresponding to the maximum braking force is input. An electronic brake control method for a vehicle, characterized in that the rear wheel braking force is increased to a greater extent than the slope to point E.
The method of claim 12, wherein when controlling the electronic brake (EMB) of the rear wheel braking unit,
The control unit,
Based on the pedal stroke axis,
When the electronic brake (EMB) starts operating at the rear-wheel brake operation start point (C), which is later than the braking start point (S) of the front-wheel brake,
The electronic brake system of the vehicle is characterized in that it is controlled to include an invalid stroke section between the rear wheel brake operation start point (C) and the start point (B) of the actual braking section where the electronic brake (EMB) generates actual braking force. Brake control method.
The method of claim 15, to compensate for a section in which the electronic brake (EMB) does not operate from the braking start point (S) of the front wheel brake unit to the operation start point (C) of the rear wheel brake unit,
The control unit,
The slope from the starting point (B) of the actual braking section to the point (E) at which the pedal stroke corresponding to the maximum braking force is input is the slope at which the pedal stroke corresponding to the maximum braking force is input from the braking start point (S) of the front wheel brake unit. An electronic brake control method for a vehicle, characterized in that the rear wheel braking force is increased to a greater extent than the slope to the point (E).

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