Brake controller, brake control method and brake control system

A brake controller is configured to control a brake device. The brake device applies a braking force to each of wheels by moving a pad toward a rotor provided for each of the wheels and pressing the pad against the rotor. The brake controller includes: a pressing force detection section configured to detect a pressing force information corresponding to a pressing force by which the pad is pressed against the rotor during braking; a stroke detection section configured to detect a stroke information corresponding to a stroke amount of the pad toward the rotor during braking, wherein the brake controller distributes the braking force to each of the wheels such that the pressing force is in a range other than a predetermined range, and sets the predetermined range based on the pressing force information and the stroke information.

INCORPORATION BY REFERENCE

The disclosure of Japanese Patent Application No. 2017-088923 filed on Apr. 27, 2017 including the specification, drawings and abstract is incorporated herein by reference in its entirety.

BACKGROUND

1. Technical Field

The disclosure relates to a brake controller, a brake control method and a brake control system each of which controls driving of a brake device provided for each wheel.

2. Description of Related Art

A braking system is disclosed in Japanese Patent Application Publication No. 2014-69602 (JP 2014-69602 A), and the braking system includes: a disc rotor provided for each wheel; a caliper provided on each of the disc rotors; a piston provided in each of the calipers; and a brake pad pressed against the disc rotor by strokes of the piston. This braking system is driven when a control unit controls a pressing force of the brake pad against the disc rotor.

The control unit disclosed in JP 2014-69602 A stores a brake noise region that corresponds to a range of the pressing force of the brake pad where brake noise is generated. In the case where the pressing force of the individual brake pad falls within the brake noise region, the pressing force of the individual brake pad is adjusted to fall out of the range corresponding to the brake noise region while an entire braking force of a vehicle is maintained.

SUMMARY

When the brake pad is worn over time, the brake noise region where the brake noise is generated is also changed over time. Since the brake noise region is static for the braking system disclosed in JP 2014-69602 A, the brake noise is possibly generated when the brake pad is worn. Meanwhile, in the case where the brake noise region is set to be a large region in advance in consideration of wear of the brake pad, the adjustment of the braking force, which is performed to avoid the pressing force from falling within the brake noise region, possibly becomes difficult.

The disclosure provides a brake, a brake control method and a brake control system controller capable of preventing generation of brake noise in accordance with a state of a brake pad.

An aspect of the present disclosure is related to a brake controller configured to control a brake device, the brake device applying a braking force to each of wheels by moving a pad toward a rotor provided for each of the wheels and pressing the pad against the rotor, the brake controller configured to distribute the braking force to each of the wheels such that a pressing force by which the pad is pressed against the rotor during braking is in a range other than a predetermined range, the brake controller including: a pressing force detection section configured to detect a pressing force information corresponding to the pressing force; and a stroke detection section configured to detect a stroke information corresponding to a stroke amount of the pad toward the rotor during braking, wherein the brake controller sets the predetermined range based on the pressing force information and the stroke information.

The brake controller according to the above aspect may derive the predetermined range as a noise region corresponding to a range of the pressing force where brake noise is generated.

The brake controller according to the above aspect may further include a contact rigidity derivation section configured to derive, based on the pressing force information and the stroke information, a contact rigidity of the pad which comes into contact with the rotor, wherein the brake controller may derive the predetermined range in accordance with the contact rigidity.

With the brake controller according to the above aspect, the noise region where the brake noise is generated is derived in accordance with the contact rigidity, and brake control to avoid the brake noise is executed. By deriving the noise region in accordance with the contact rigidity, the braking force for each of the wheels can be distributed in consideration of a state of the pad such as wear, and generation of the brake noise can thereby be prevented.

The brake controller according to the above aspect may adjust the predetermined range such that the pressing force is reduced as the contact rigidity is increased.

The brake controller according to the above aspect may derive a first predetermined range as the predetermined range such that the pressing force is reduced from a predetermined region in a case where the contact rigidity is equal to or higher than a specified value, and the brake controller may derive a second predetermined range as the predetermined range such that the pressing force is increased from the first predetermined range in a case where the contact rigidity is lower than the specified value.

With the brake controller according to the above aspect, the appropriate noise region can be set in accordance with the contact rigidity.

In the brake controller according to the above aspect, the pad of the brake device may be stroked toward the rotor by driving a motor; the pressing force detection section may detect the pressing force information based on an output of a load sensor that detects the pressing force or an output of a current value acquisition section that acquires a current value supplied to the motor; and the stroke detection section may detect the stroke information based on an output of a stroke sensor that detects the stroke amount of the pad or an output of a rotation angle detection section that detects a rotation angle of the motor.

In the above aspect, in the electric brake device that is driven by the motor, the output of the sensor that is used for feedback, a failure determination, and the like is also used for prevention control of the brake noise. Therefore, with the brake controller according to the above aspect, the sensor can be shared, and the cost thereof can be cut.

The brake controller according to the above aspect may distribute the braking force for each of the wheels so as not to apply the pressing force equal to or smaller than a specified pressing force to the rotor of at least one of a front wheel and a rear wheel.

With the brake controller according to the above aspect, the brake noise, which is possibly generated during braking with the small pressing force, can be prevented.

The brake controller according to the above aspect may further include a braking force computation section. The braking force computation section may be configured to compute a total braking force for a vehicle, wherein the brake controller may distribute the braking force only to a front wheel or only to a rear wheel in a case where the total braking force that is computed by the braking force computation section is smaller than a specified value.

Another aspect of the present disclosure is related to a brake control method for controlling a brake device, the brake control method setting a pressing force by which a pad of the brake device is pressed against a rotor of the brake device during braking such that the pressing force is in a range other than a predetermined range, the brake control method including: detecting a pressing force information corresponding to the pressing force; detecting a stroke information corresponding to a stroke amount of the pad toward the rotor during braking; and setting the predetermined range based on the pressing force information and the stroke information.

Another aspect of the present disclosure is related to a brake control system. The brake control system includes: a brake device including a pad and a rotor, the brake device applying a braking force to each of wheels by moving the pad toward the rotor provided for each of the wheels and pressing the pad against the rotor; and a brake controller configured to: detect a pressing force information corresponding to a pressing force by which the pad is pressed against the rotor during braking; detect a stroke information corresponding to a stroke amount of the pad toward the rotor during braking; distribute the braking force to each of the wheels such that the pressing force is in a range other than a predetermined range; and set the predetermined range based on the pressing force information and the stroke information.

The disclosure can provide the brake controller, the brake control method and the brake control system capable of preventing the generation of the brake noise in accordance with the state of the pad.

DETAILED DESCRIPTION OF EMBODIMENTS

FIG. 1is a diagram illustrating a functional configuration of a brake controller10according to an embodiment. The brake controller10executes control for adjusting a braking force to be applied to each wheel of a vehicle so as to prevent abnormal noise, that is, so-called brake noise generated during braking.

The brake controller10includes a braking operation detection section12, a pressing force detection section14, a stroke detection section16, and a processing section18and controls driving of a brake device20.

The braking operation detection section12detects a braking operation by a driver and sends a detection result to the processing section18. The braking operation detection section12detects an operation amount of a brake pedal, for example. The processing section18decides the braking force to be applied to each of the wheels on the basis of the detection result of the braking operation detection section12.

The brake device20is provided for each of the wheels and applies the braking force to the corresponding wheel by driving a motor. The braking force corresponds to a braking command from the processing section18. The brake device20on a front wheel side may be configured to have higher output performance than the brake device20on a rear wheel side and to be able to generate the larger braking force than the brake device20on the rear wheel side.

The motor in the brake device20is provided for each of the wheels, can independently be driven for the corresponding wheel in accordance with a command signal from the processing section18, and can apply the braking force that differs by the wheels. An electric motor used to brake has superior braking responsiveness of the corresponding wheel when compared with the using of brake fluid, and can accurately control the braking force of the corresponding wheel.

FIG. 2is a view illustrating the brake device20. The brake device20includes a motor19, pads42,43, a piston44, and a caliper46. The pad42is pressed against a rotor40that coaxially rotates with a wheel. The pads42,43are provided in one pair and are opposite to each other with the rotor40being held between the pads42,43. The pad42has a plate-shaped base metal42a, and the base metal42ais coupled to the piston44. A base metal43aof the pad43is coupled to the caliper46.

The piston44is coupled to the one pad42and causes the pad42to stroke toward the rotor40. That is, the piston44causes the pad42to advance toward or retreat from the rotor40by driving of the motor19. A stroke amount of the piston44in a stroke direction48is detected by the stroke detection section16and corresponds to a stroke amount of the base metal42aof the pad42.

The caliper46is supported on a vehicle body side and can move along the stroke direction48of the piston44. When the one pad42is pressed against the rotor40by the stroke of the piston44, the caliper46moves in an opposite direction by a reaction force, and the other pad43is pressed against the rotor40. In this way, the rotor40is held and pressed by the pad42, and thereby apply a brake on the wheel.

Referring back toFIG. 1, the pressing force detection section14detects pressing force information on a pressing force to press the pad42against the rotor40during braking, and sends a detection result to the processing section18. The pressing force detection section14is a load sensor that is attached to the brake device20and detects the pressing force that is applied to the base metal42aof the pad42, for example. Alternatively, the pressing force detection section14may be a current acquisition section that acquires a current value supplied to the motor19. The pressing force detection section14detects the pressing force information on the basis of output of the load sensor or the current acquisition section for the motor19.

The stroke detection section16detects stroke information on a stroke amount of the pad42with respect to the rotor40during braking. That is, the stroke detection section16detects a deformation amount of the pad42at a time when the pad42is pressed against the rotor40during braking, and sends a detection result to the processing section18. The stroke detection section16detects the stroke amount of the piston44, that is, the stroke amount of base metal42aof the pad42, in the stroke direction48shown inFIG. 2. The stroke detection section16is a stroke sensor that detects a moving distance of the pad42in the stroke direction48, for example. The stroke sensor may be provided on the piston44and detects the stroke amount of the piston44, so as to be able to detect the stroke amount of the pad42that moves together with the piston44. Alternatively, the stroke detection section16may be a rotation angle detection section that detects a rotation angle of the motor19. The stroke detection section16detects the stroke information on the basis of output of the stroke sensor or the rotation angle detection section.

In the brake device20that uses the electric motor19as a drive source, the output of the load sensor or the current acquisition section and the stroke sensor or the rotation angle detection section are used for brake control feedback, a fail determination of the brake control, and the like. When the same sensors as that used for feedback control and the like are used for control to prevent the brake noise, the sensors can be shared in plural types of the control, and thus cost can be reduced.

The processing section18receives the detection result from each of the detection sections, computes a target braking force of the entire vehicle on the basis of the detection results, decides an individual braking force for each of the wheels on the basis of the target braking force, drives each of the motors19in accordance with the decided individual braking force, and makes the brake device20execute braking.

The processing section18can be configured by including a circuit block, memory, and large-scale integration (LSI) as hardware, and can also be realized by a program that is loaded in the memory as software. The functional blocks of the processing section18can be realized by any of various configurations that include the hardware only, the software only, or a combination of hardware and software, and thus the processing section18is not limited to any of the foregoing configurations.

The processing section18has a target braking force computation section24, a pressing force acquisition section26, a stroke acquisition section28, a braking force distribution section30, a contact rigidity derivation section32, and a drive control unit34. The target braking force computation section24computes the target braking force of the entire vehicle on the basis of the detection result of the braking operation detection section12, and computes the individual target braking force for each of the wheels on the basis of the target braking force of the entire vehicle. The target braking force computation section24sends the computed individual target braking force for each of the wheels to the braking force distribution section30.

The pressing force acquisition section26acquires the pressing force information from the pressing force detection section14. The stroke acquisition section28acquires the stroke information from the stroke detection section16. The pressing force acquisition section26and the stroke acquisition section28send the pressing force information and the stroke information to the contact rigidity derivation section32.

The contact rigidity derivation section32derives contact rigidity K between the pad42and the rotor40on the basis of the pressing force information and the stroke information. The contact rigidity K corresponds to a spring constant of the pad42that vibrates during braking.

A relationship between a pressing force P and a stroke value S for the contact rigidity K is expressed by the following equation (1).
K=P/S(1)
The pressing force P is a force by which the pad42is pressed against the rotor40after the pad42abuts the rotor40. The stroke value S is a distance for which the base metal of the pad42moves in the stroke direction48after the pad42abuts the rotor40. The stroke value S is zero when the pad42starts abutting the rotor40. The contact rigidity K is derived at timing at which the pad42starts abutting the rotor40, and the abutment of the pad42against the rotor40is detected by the load sensor in the pressing force detection section14. Just as described, the contact rigidity K is derived from the pressing force information on the pad42being pressed against the rotor40and the stroke information indicative of the deformation amount by which the pad42is pressed against the rotor40and is deformed.

The contact rigidity K is reduced with progress of wear of the pad42over time. The contact rigidity K is also changed by a temperature, and the contact rigidity K is increased as the temperature increases. A frequency of the pad42that vibrates at the time of contacting the rotor40can be computed by using the contact rigidity K, and a noise region of the pressing force where a possibility of generation of the brake noise is high can be derived.

FIG. 3AandFIG. 3Billustrates the noise region of the pressing force. In each ofFIG. 3AandFIG. 3B, a vertical axis represents a resonance frequency RF, and a horizontal axis represents the pressing force P. A first resonance line50represents a resonance analysis result of a rotor system, that is, the pad42that comes into contact with the rotor40and vibrates during braking. A second resonance line52represents a resonance analysis result of a caliper system during braking.

The resonance analysis results shown inFIG. 3Aindicate that the brake noise is likely to be generated in the case where the pressing force P falls within a noise region A1. Therefore, the pressing force should avoided falling within the noise region A1in order to restrain the generation of the brake noise. The brake noise is generated when the resonance frequency RF of the rotor system and the resonance frequency RF of the caliper system come close to each other. In the noise region A1, the resonance frequency RF of the rotor system and the resonance frequency RF of the caliper system have values that are close to each other. The range of the pressing force P indicated by the noise region A1is set for each type of the brake device20by an experiment or the like.

This noise region A1is shifted on the basis of the contact rigidity K, that is, due to a state change of the pad42such as a degree of wear of the pad42, a temperature of the pad42, and the like. The resonance analysis results shown inFIG. 3Bindicate a case where the contact rigidity K is lower than that in the resonance analysis results shown inFIG. 3A, and also indicate a state where the wear of the pad42is progressed. In the second resonance line52of the caliper system, the resonance frequency RF is not changed by the contact rigidity K. Meanwhile, in the first resonance line50of the rotor system including the pad42, as the contact rigidity K is reduced, the resonance frequency RF is changed to be reduced as shown inFIG. 3B.

As shown inFIG. 3B, when the resonance frequency RF on the first resonance line50of the rotor system is reduced, a range where the first resonance line50approximates the second resonance line52of the caliper system is changed, and a noise region A2is shifted to a side where the pressing force is large. That is, when the contact rigidity K is reduced due to the progress of wear of the pad42, the brake noise is generated with the large pressing force. Meanwhile, when the contact rigidity K is increased due to the temperature increase, the brake noise is generated with the small pressing force.

The braking force distribution section30derives the noise region in accordance with the contact rigidity K that is received from the contact rigidity derivation section32during braking, and distributes the individual target braking force to each of the wheels in such a manner as to avoid the pressing force that falls within the derived noise region. The pressing force of the pad42is proportional to the individual target braking force, and the braking force distribution section30has a map or an equation used to compute the pressing force of the pad42from the braking force for each of the wheels. The braking force distribution section30adjusts the individual target braking force for each of the wheels (the pressing force of the pad42) so as to maintain the target braking force of the entire vehicle. When the noise region is set in accordance with the contact rigidity K and the individual target braking force for each of the wheels is thereby adjusted, the generation of the brake noise can be prevented with the state of the pad42such as a worn state and the temperature of the pad42being reflected. In addition, the state of the pad42can be detected from the contact rigidity K. Thus, the noise region may not have to be set large when taking the wear of the pad42into consideration. Therefore, the noise region can be set accurately.

The braking force distribution section30may have a map that represents a relationship between the contact rigidity K and the noise region, and may also have an equation used to compute the noise region from the contact rigidity K. In the case where types of the brake device20differ between the front wheel and the rear wheel, the braking force distribution section30may derive the different noise regions for the front wheel and the rear wheel. As the contact rigidity K is increased, the braking force distribution section30derives the noise region where the range of the pressing force P is shifted such that the pressing force is reduced. As the contact rigidity K is reduced, the braking force distribution section30derives the noise region where the range of the pressing force P is shifted such that the pressing force is increased. That is, in a state where the contact rigidity K is high, an upper limit of the range of the pressing force P is low when compared with an upper limit of the range of the pressing force P in a state where the contact rigidity K is low. Furthermore, in a state where the contact rigidity K is high, an lower limit of the range of the pressing force P is low when compared with an lower limit of the range of the pressing force P in a state where the contact rigidity K is low.

In addition, the braking force distribution section30executes small pressing force control in which the individual target braking force is distributed so as not to apply the pressing force equal to or smaller than a specified pressing force to the rotor40of each of the wheels. More specifically, in the case where the target braking force for at least one of the front wheel and the rear wheel is equal to or smaller than a specified value, or in the case where the pressing force of the pad42that is applied to the rotor40of at least one of the front wheel and the rear wheel is equal to or smaller than the specified pressing force, the braking force distribution section30distributes the individual target braking force such that the individual target braking force for one of the front wheel and the rear wheel is set to zero while the individual target braking force for the other of the front wheel and the rear wheel is increased. For example, in the case where the pressing force P for the rear wheels are equal to or smaller than the specified pressing force, the braking force distribution section30sets the pressing force P for the rear wheels to zero and adds a magnitude of the pressing force P corresponding to that for the rear wheel to the pressing force P for the front wheels.

FIG. 4is a graph illustrating the distribution of the braking force to each of the wheels. This example represents a relationship between the front wheels and the rear wheels in terms of the pressing force distribution. A normal distribution line60represents the distribution of the pressing force (the braking force) to the front and rear wheels during normal braking. An ideal distribution line62represents the ideal distribution of the pressing force (the braking force) to the front and rear wheels. A vertical axis represents the pressing force for the rear wheels, and the horizontal axis represents the pressing force for the front wheels. As indicated by the normal distribution line60, when the target braking force for all of the wheels corresponds to a point a, the pressing force is distributed such that a pressing force Pf for the front wheels is larger than a pressing force Pr for the rear wheels.

For example, in the case where the pressing force for the rear wheels is larger than a specified pressing force Pt, the braking force distribution section30decides the individual target braking force for each of the front and rear wheels in accordance with the normal distribution line60. In the case where the pressing force for each of the wheels falls within the noise region, the braking force distribution section30adjusts the individual target braking force decided by using the normal distribution line60such that the pressing force for each of the wheels avoids the noise region, that is, the pressing force for each of the wheels does not fall within the noise region. In the case where the pressing force for each of the wheels falls within the noise region, the braking force distribution section30adjusts the individual target braking forces by increasing the individual target braking force for the rear wheel and reducing the individual target braking force for the front wheel, so as to maintain the entire target braking force, for example. Note that the braking force distribution section30may distribute the braking force for the front and rear wheels in accordance with the ideal distribution line62.

In the case where the pressing force for the rear wheel is equal to or smaller than the specified pressing force Pt, the braking force distribution section30executes the small pressing force control. In the case where the pressing force for the rear wheel is equal to the pressing force Pt, the braking force distribution section30sets the pressing force for the rear wheel to zero in accordance with a constant G line64that is used to maintain the target braking force of the entire vehicle. Then, the braking force distribution section30adds the magnitude of the pressing force corresponding to that for the rear wheel to the pressing force of the front wheel so as to set a pressing force Pa for the front wheel.

In this way, the braking force distribution section30can prevent braking with the pressing force that is equal to or smaller than the specified pressing force Pt, so as not to press the pad42against the rotor40with the extremely small pressing force P. This is because there is a possibility that a relationship between the pressing force and the noise region is not established when the pressing force is extremely small, and there is a case where it is difficult to adjust the individual target braking force for a purpose of avoiding the noise region. In view of the above, in the case where the pressing force for each of the wheels is equal to or smaller than the specified pressing force, or in the case where the target braking force is equal to or smaller than a specified braking force, the braking force distribution section30executes the small pressing force control to apply a brake only to the front wheels or only to the rear wheels, so as to prevent the generation of the brake noise. In the case where the pressing force for each of the wheels is larger than the specified pressing force Pt, or in the case where the target braking force is larger than the specified braking force, the braking force distribution section30executes normal control to avoid the generation of the brake noise.

On the basis of the individual target braking force for each of the wheels that is distributed by the braking force distribution section30, the drive control unit34sends a drive signal for driving the motor19of the brake device20for each of the wheels. In this way, the generation of the brake noise in each of the wheels can be prevented.

FIG. 5is a flowchart illustrating the control to avoid the brake noise. The target braking force computation section24computes the target braking force of the entire vehicle on the basis of the output of the braking operation detection section12, and computes the individual target braking force for each of the wheels (S12).

The braking force distribution section30receives the target braking force that is computed by the target braking force computation section24, and determines whether the target braking force is equal to or larger than the specified value (S14). If the target braking force is not equal to or larger than the specified value (N in S14), the braking force distribution section30maintains the target braking force of the entire vehicle while distributing the individual target braking force such that the individual target braking force for one of the front wheel and the rear wheel is set to zero and the individual target braking force for the other of the front wheel and the rear wheel is increased. The drive control unit34drives each of the brake devices20according to the distributed individual target braking force (S30). In this way, the generation of the brake noise can be prevented while application of the pressing force that is equal to or smaller than the specified pressing force is prevented for braking.

If the target braking force is equal to or larger than the specified value (Y in S14), the drive control unit34starts braking (S16). The motor19of the brake device20is driven by the drive control unit34, the piston44causes the stroke of the pad42toward the rotor40, and the pad42abuts the rotor40. At this time, the pressing force acquisition section26acquires the pressing force P of the pad42against the rotor40, and the stroke acquisition section28acquires the stroke value S of the pad42toward the rotor40(S18).

The contact rigidity derivation section32derives the contact rigidity K on the basis of the pressing force P and the stroke value S that are acquired (S20). The braking force distribution section30derives the noise region of the pressing force in accordance with the contact rigidity K and determines whether a target pressing force of the pad42that corresponds to the individual target braking force for each of the wheels falls within the noise region (S22).

If the target pressing force of the pad42does not fall within the noise region (N in S22), the drive control unit34drives the motor19and applies the target braking force to each of the wheels without adjusting the individual target braking force for each of the wheels.

If the target pressing force of the pad42falls within the noise region (Y in S22), the braking force distribution section30maintains the target braking force of the entire vehicle while distributing the individual target braking force for each of the wheels in the manner to avoid the pressing force that falls within the noise region (S24). The drive control unit34drives each of the motors19on the basis of the distributed individual target braking force and applies the distributed braking force to each of the wheels. In this way, the generation of the brake noise can be prevented.

The disclosure has been described so far on the basis of the embodiment. The disclosure is not limited to the embodiment, and various modifications such as a design change can be made thereto. The configuration shown in each of the drawings merely illustrates one example and can appropriately be changed as long as the configuration can achieve the same functions.

In the embodiment, such an aspect that the motor19is used as the drive source of the brake device20has been described. However, the disclosure is not limited to this aspect. For example, the brake device20may be a hydraulic brake device that supplies pressurized brake fluid to the brake device20.

In addition, in the embodiment, such an aspect that, if the target braking force is not equal to or larger than the specified value (N in S14ofFIG. 5), the braking force distribution section30executes the small pressing force control in which the individual target braking force is distributed so as not to apply the pressing force equal to or smaller than the specified pressing force to the rotor40of each of the wheels has been described. However, the disclosure is not limited to this aspect. For example, in the case where the small pressing force control is not executed and the target braking force is not equal to or larger than the specified value, the braking force distribution section30may decide the individual target braking forces for the front and rear wheels in accordance with the normal distribution line60and adjust the individual target braking forces such that the pressing force for each of the wheels avoids the noise region.

Furthermore, in the embodiment, such an aspect, in which as the contact rigidity K is increased, the braking force distribution section30derives the noise region where the range of the pressing force P is shifted such that the pressing force is increased, has been described. However, the disclosure is not limited to this aspect. For example, in the case where the contact rigidity K is equal to or higher than a specified value, a first noise region where the range of the pressing force P is shifted from a predetermined region such that the pressing force is reduced may be derived. In the case where the contact rigidity K is lower than the specified value, a second noise region where the range of the pressing force P is shifted such that the pressing force is increased from the first noise region may be derived. For example, the region A2shown inFIG. 3Bcorresponds to an example of the first noise region, and the region A1shown inFIG. 3Acorresponds to an example of the second noise region. Note that the noise region may freely be set according to an experiment or the like as long as the noise region includes the range of the pressing force where the resonance frequency RF of the rotor system and the resonance frequency RF of the caliper system are close to each other.

Furthermore, in order to make the present disclosure easy to understand, in the embodiment, the brake controller is constituted by a plurality of sections as shown inFIG. 1. However, the present disclosure is not limited to this, and these sections can be combined or further divided. For example, the braking force distribution section30may be combined with the contact rigidity derivation section32, the pressing force acquisition section26and the stroke acquisition section28and constitute a section that is able to distribute braking force based on the pressing force information and the stroke information received from the pressing force detection section14and the stroke detection section16.

Note that the disclosure may be realized in various forms, for example as a control method for a brake, a control system for executing the control method, and so on.