JP2011183921A - Braking force control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent control hunting of a boosting linear control valve caused by a reverse input. <P>SOLUTION: When fluctuation of brake cylinder hydraulic pressure is caused due to wear of a brake disc and eccentricity of a drum, the fluctuation of the brake cylinder hydraulic pressure is not suppressed in many cases, even if supply current to the boosting linear control valve and a pressure reducing linear control valve is suppressed. In this case, operation intervals of the boosting linear control valve and the pressure reducing linear control valve can be lengthened if a width of non-sensitive zone is increased, thereby preventing the control hunting. If the width of non-sensitive zone is gradually increased, while detecting a state of the fluctuation of the brake cylinder hydraulic pressure, the width of non-sensitive zone can be changed into a proper size. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a brake force control device that controls a brake force of a brake that suppresses rotation of a wheel.

Patent Document 1 describes that a change in the brake cylinder hydraulic pressure accompanying the rotation of the wheel is detected in a state in which the brake cylinder hydraulic pressure is maintained, thereby changing the dead band width. When the dead zone width is large, it is difficult to start the pressure increase control and the pressure reduction control from the holding control, and there is a possibility that the pressure increase and the pressure reduction are delayed. On the other hand, when the dead zone width is small, hunting is likely to occur. Therefore, if the dead zone width is reduced when the change in the brake cylinder hydraulic pressure is small during the holding control, the pressure increase / decompression delay can be suppressed while suppressing the hunting.
In Patent Document 2, the hunting level is detected based on the number of times of switching of the hydraulic pressure control valve that can control the hydraulic pressure of the brake cylinder, and when the hunting level is high, the supply current to the hydraulic pressure control valve is reduced. It is described to do.
Patent Document 3 describes that the plurality of rules used when controlling the supply current to the electromagnetic control valve is changed depending on whether the amplitude of the pulsation of the brake cylinder hydraulic pressure is large or small. . For example, it is generally known that the amplitude of the pulsation is larger in the drum brake than in the disc brake, but when the brake cylinder hydraulic pressure of the drum brake is controlled, the dead zone width is increased, When the holding control is switched to the pressure increase control and the pressure reduction control, the amount of current supplied to the electromagnetic control valve is reduced. Thereby, hunting can be suppressed and a sudden change in the brake cylinder hydraulic pressure can be suppressed.

JP 2006-142943 A Patent 3778811 Patent 4289050

  An object of the present invention is to improve a braking force control device.

Means and effects for solving the problem

In the brake force control apparatus according to the present invention, the brake force is controlled according to a plurality of rules. And even if the content of the 1st rule of a plurality of rules is changed, when the vibration state of brake force is not improved, the content of the 2nd rule is changed.
When the cause of the vibration state of the brake force is on the input side (brake force control side), the vibration state can be improved by changing the contents of the first rule.
On the other hand, if the vibration state is not improved even if the contents of the first rule are changed, it is considered that there is a cause on the output side (brake) instead of a cause on the input side.
Therefore, when it is considered that vibration has occurred due to the cause on the output side (hereinafter, sometimes referred to as vibration due to reverse input), the content of the second rule is changed. By changing, the operation frequency of the brake force control mechanism can be lowered.

Patentable invention

  In the following, the invention that is claimed to be claimable in the present application (hereinafter referred to as “claimable invention”. The claimable invention is at least the “present invention” to the invention described in the claims. Some aspects of the present invention, including subordinate concept inventions of the present invention, superordinate concepts of the present invention, or inventions of different concepts) will be illustrated and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is merely for the purpose of facilitating understanding of the claimable invention, and is not intended to limit the set of components constituting the claimable invention to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention.

(1) A brake force control mechanism that can control a brake force of a brake that suppresses rotation of a vehicle wheel, and that controls the brake force control mechanism according to a plurality of rules, thereby bringing the brake force closer to a target value. A force control device,
A vibration state detection device for detecting a state of vibration of the brake force;
A first rule changing unit that changes the content of a first rule that is at least one of the plurality of rules based on a vibration state detected by the vibration state detection device;
Even if the first rule is changed by the first rule changing unit, if the vibration state detected by the vibration state detection device does not improve, at least one of the rules excluding the first rule from the plurality of rules. And a second rule changing unit that changes the content of the second rule, which is one rule.
The brake is a friction brake that suppresses the rotation of the wheel by pressing the friction member against a brake rotating body that rotates together with the wheel to cause frictional engagement. Further, the brake may be a hydraulic brake that presses the friction member against the brake rotating body by the hydraulic pressure of the brake cylinder, or an electric brake that presses the brake member by electromagnetic driving force.
As will be described later, the brake force control mechanism is capable of controlling the hydraulic pressure of the brake cylinder as a brake force (a pressing force that presses the friction member against the brake rotating body). The pressure (output) may be controllable. The brake force control mechanism may be an actuator control mechanism that controls an operation state of an actuator (a brake cylinder or an electric motor) that operates a brake (generates a brake force). Examples of the hydraulic pressure control mechanism that can control the hydraulic pressure of the brake cylinder include a solenoid valve, a pump motor that can control the discharge pressure of the pump, and the like.
The vibration state of the brake force refers to a change state of the brake force, but can also be represented by an operation state of a mechanism (for example, an electromagnetic valve, an electric motor, etc.) that is operated in accordance with the change of the brake force. For example, the vibration state can be represented by the number of times the braking force has changed beyond a threshold value within the set time and the number of times the electromagnetic valve has been operated within the set time. The number of changes and the number of actuations within the set time can be referred to as the brake force change frequency and the control mechanism actuation frequency.
If the vibration state of the brake force does not improve, the change range (amplitude) of the brake force does not become smaller than the vibration state before the change of the first rule, and it has changed beyond the threshold value within the set time. This means that the number of times or the number of actuations of the solenoid valve is not reduced.
The target value of the braking force is determined based on the driver's intention to brake, determined based on the running state of the vehicle (for example, slip state), or based on the relative positional relationship with the preceding vehicle and surrounding objects. The size can be determined. Further, when both the regenerative braking torque and the friction braking torque are applied to the vehicle, the target value of the friction braking torque is determined in consideration of the magnitude of the output regenerative braking torque in addition to the above-described circumstances. (Regenerative cooperative control).
The contents of the first rule are contents that affect the vibration of the braking force caused by the input side. By changing the contents of the first rule, it is possible to suppress the vibration of the braking force caused by the input side.
The contents of the second rule affect the presence or absence of the operation of the brake force control mechanism, and the operation frequency of the brake force control mechanism can be lowered by changing the contents of the second rule. In addition, the component of the brake force control mechanism in which the presence or absence of an operation | movement is determined by the 2nd rule and the component by which the operation frequency is reduced by the change of the content of the 2nd rule may be the same or different.
The rule for controlling the brake force control mechanism includes a rule for determining the magnitude of the supply current (which can be referred to as a current value or a current amount) (for example, the first rule), whether the current is supplied A rule for determining whether or not (for example, it can be a second rule) is applicable. It can be considered that the rule for determining whether or not to operate the electromagnetic valve included in the brake force control mechanism corresponds to the rule for determining whether or not to supply current to the brake force control mechanism.
In the braking force control apparatus described in this section, the content of the second rule is changed after the content of the first rule is changed. However, when the content of the second rule is changed, Even if the contents remain changed, the contents can be brought close to the contents before the change or can be returned to the contents before the change (the change is reset). When the content of the first rule is changed based on the vibration state of the braking force, if the vibration state is improved by changing the content of the second rule, the content of the first rule is returned to the content before the change. However, it is considered that the vibration state does not deteriorate.
(2) The brake force control device controls the supply current to the brake force control mechanism according to at least the first rule and the second rule, so that the brake force is determined by the target value and the dead band width. A braking force control unit using current control that holds the braking force when inside the determined dead zone, and increases or decreases the braking force when the braking force is outside the dead zone;
Current that changes the content of the rule that determines the amount of current supplied to the brake force control mechanism when the first rule change unit increases or decreases the brake force as the first rule (1) In the paragraph (1), the second rule changing unit includes a dead band changing unit that changes the dead band width representing the content of the dead band determining rule as the second rule. The brake force control apparatus as described.
The content of the first rule that determines the amount of current is changed based on the vibration state. For example, when the brake force change frequency is high in the content of the first rule, the amount of operation of the brake force control mechanism is smaller when the actual brake force and the target value are the same than when the frequency is low. The supply current amount can be changed to the content that is determined so that the start of the operation is delayed. Specifically, it corresponds to reducing the value of the control gain or reducing the current value at the start of operation.
The dead zone width, which is the content of the second rule that determines the dead zone, is changed when the vibration state is not improved by changing the content of the first rule. If the dead zone width is increased, there are more opportunities for the brake force to be maintained, and there are fewer opportunities for the brake force to be increased or decreased, and the frequency of operation of the brake force control mechanism can be reduced.
(3) The vibration state detection device includes a dead band use vibration state detection unit that detects the vibration state based on a frequency at which the braking force changes from the inside to the outside of the dead band.
The frequency of the vibration state detected by the dead-zone use vibration state detection device after the second rule change unit has changed the content of the first rule to the set content by the first rule change unit is the set content. The brake force control device according to (2), further including a non-improvement change unit that changes the dead band width when the frequency of the vibration state detected by the vibration state detection device before the change is not lower than the frequency. .
When the vibration state of the braking force is expressed by the frequency at which the braking force changes from the inside to the outside of the dead zone, even if the content of the first rule is changed to the setting content, It is considered that the vibration is caused by reverse input. For example, when the contents of the first rule can be changed step by step, the setting contents can be changed at a predetermined stage, and if changed to the setting contents, It can be set as the content considered that the vibration by a cause can be suppressed.

(4) The dead band width changing unit includes a dead band width gradually increasing unit that gradually increases the dead band width until the frequency of the vibration state detected by the dead band using vibration state detecting unit reaches a stable set frequency. The braking force control device according to item (3), wherein the dead zone width gradually increased by the width gradually increasing unit is defined as the dead zone width after change.
When it is determined that the vibration is caused by the reverse input, the actual dead band width is gradually increased until the frequency reaches the stable side setting frequency. As a result, the dead zone width can be changed to an appropriate size.
The stable side setting frequency may be a fixed value or a variable value determined based on the vibration state before the first rule is changed to the setting content. For example, the first rule may be the setting content. It is also possible to achieve a state improved from the vibration state before the change.
Note that even if the dead zone width is increased, the actual vibration state of the braking force is not always improved. However, when the vibration state is evaluated by the number of times the braking force has changed beyond the dead band, the evaluation value of the vibration state may be improved by increasing the dead band width (appearingly improved). Can think). In addition, when the braking force control mechanism is activated when the braking force changes beyond the dead zone, the operating frequency of the braking force control mechanism can be lowered if the evaluation value (frequency) of the vibration state is lowered. It becomes.

(5) The dead band width changing unit includes a temporary dead band width setting unit that temporarily sets the dead band width, and the dead band using vibration state detecting unit is set to the temporary dead band width and the brake set by the temporary dead band width setting unit. The brake force control device according to any one of (2) to (4), including a provisional dead-zone-use vibration state estimation unit that estimates the vibration state based on force.
(6) The provisional dead band width that the provisional dead band width gradually increases until the frequency of the provisional vibration state estimated by the provisional dead band use vibration state detection unit reaches the provisional stable side setting frequency. The brake force control device according to item (5), including a gradually increasing portion.
(7) When the provisional dead zone use vibration state detection unit controls the current supplied to the brake force control mechanism by the current control use brake force control unit, the provisional dead band width setting unit The brake force control device according to item (5) or (6), further including a provisional vibration state detection unit that tentatively detects the vibration state based on the provisional dead band width set by (5).
(8) The provisional vibration state detection unit is configured such that a current supplied to the brake force control mechanism is controlled by the current control utilizing brake force control unit, and the first rule change unit performs the first rule change. The brake force control apparatus according to item (7), including a change permission detection unit that temporarily detects the vibration state when the change is permitted.
The relationship between the vibration caused by the reverse input and the operation of the brake force control mechanism is low. Therefore, even if the brake force control mechanism is controlled by the current control utilizing brake force control unit, it is possible to detect the vibration state of the brake force resulting from the reverse input.
A temporary dead zone is obtained based on the actual target value and the temporary dead zone width, and the frequency at which the actual braking force changes from the inside to the outside of the temporary dead zone is obtained based on the temporary dead zone and the actual braking force. It is done. Then, the provisional dead band width is gradually increased until the frequency reaches the provisional stable side setting frequency.
However, since the dead band width is set temporarily, even if the brake force changes from the inside to the outside of the temporary dead band width, the brake force control mechanism is not activated using that as a trigger.
Detection of the temporary vibration state based on the temporary dead band width is performed in a state where the brake force control mechanism is controlled according to a plurality of rules including the first rule and the second rule. In this case, it is desirable that the vibration state is detected based on the dead zone and the braking force, and the change by the first rule changing unit of the contents of the first rule is permitted.
In many cases, the dead band width used in the supply current utilizing brake force control unit is different from the temporary dead band width temporarily set by the temporary dead band width setting unit. The temporary dead band width setting unit can set the temporary dead band width regardless of the dead band width used in the supply current utilization brake force control unit.

(9) The dead band width changing unit includes a vibration state corresponding dead band width changing unit that changes the dead band width to a size corresponding to the vibration state detected by the vibration state detection device. The brake force control device according to any one of the items).
For example, the operating frequency of the brake force control mechanism can be reduced by increasing the dead band width when the amplitude represented by the vibration state is larger than when the amplitude is small, or by increasing the dead band width when the vibration state is high. can do. It is appropriate to use the vibration state represented by the frequency at which the braking force changes from the inside to the outside of the dead zone. In that case, it is desirable that the vibration state be detected by the dead zone using vibration state detection device. .
In addition, the increase amount of the dead band width can be changed to a magnitude corresponding to the vibration state.
(10) When the first rule is changed by the first rule changing unit and the vibration state is not improved, the dead band width changing unit changes to the vibration state detected by the dead band using vibration state detecting unit. The brake force control device according to any one of (2) to (9), including a reverse input determination post-vibration vibration state corresponding dead band width changing unit that changes the dead band width to a size corresponding to the size.
In the brake force control device described in this section, after it is determined that the vibration state is caused by reverse input, the vibration state is detected, and the dead band width is changed to a value corresponding to the detected vibration state. .

(11) The brake force control device includes a dead zone determining unit that determines the dead zone based on the target hydraulic pressure and the dead zone width changed by the dead zone width changing unit, and the dead zone determining unit includes (i) When the increase gradient of the target value is larger than the set increase gradient, the increase-side dead band width that is the absolute value of the difference between the target value and the switching threshold value for switching from increase control to holding control is the target value and decrease control. An increase request dead band determining unit that determines to be smaller than a decrease-side dead band width that is an absolute value of a difference between a switching threshold value to be switched to holding control, and (ii) a decrease gradient of the target value is greater than a set decrease gradient In any one of the items (2) to (10), including at least one of a decrease request dead band width determination unit that determines that the decrease-side dead band width is smaller than the increase-side dead band width when larger Listed blur Key force control device.
(12) When the brake force control device is (i) an absolute value of a difference between the target value and a switching threshold value for switching from the increase control to the holding control when the increase gradient of the target value is larger than the set increase gradient. An increase-side dead band width determining unit for an increase request for making a certain increase-side dead band width smaller than ½ of the dead band width changed by the dead-band width changing unit, and (ii) a decrease gradient of the target value from a set decrease gradient If larger, the decrease-side dead band width, which is the absolute value of the difference between the target value and the switching threshold value for switching from decrease control to hold control, is smaller than ½ of the dead band width changed by the dead band width changing unit. The braking force control device according to any one of (2) to (11), including at least one of a reduction-side dead band width determination unit that performs a reduction request.
(i) When the increase gradient of the target value (increase with respect to time) is larger than the set increase gradient, if the increase-side dead band width is reduced, it is difficult to switch from the increase control to the hold control. The force can be quickly brought close to the target value. The switching threshold value for switching from increasing control to holding control can be referred to as an increasing control end threshold value. The increase control end threshold and the pressure increase control start threshold for switching from holding control to increase control may be the same or different.
In addition to the condition that (a) the target value increase gradient is greater than the set increase gradient, (x) the target value minus the actual braking force is greater than the set deviation, and (y) the target value is set. When one or more of the following conditions are satisfied: (z) the driver operating speed of the brake operating member when the brake is applied is higher than the set speed, the increasing dead band width is decreased. It can be made smaller than the width. In addition, instead of the condition (a), when one or more of the condition (x), the condition (y), and the condition (z) are satisfied, the increase-side dead band width is reduced. It can also be.
(ii) When the decreasing gradient of the target value (the absolute value of the gradient, which is a positive value) is larger than the set decreasing gradient (positive value), if the decompression-side dead band width is reduced, the pressure reduction control is changed to the holding control. The switching can be made difficult, and the actual braking force can be quickly brought close to the target value.
In this case as well, the decrease control end threshold value and the decrease control start threshold value may be the same or different. In addition to the condition that (b) the decreasing gradient is larger than the set decreasing gradient, (x) ′ the absolute value of the deviation obtained by subtracting the actual braking force from the target value is larger than the set deviation, (z) ′ the driver If the conditions such as the operating speed when releasing the brake operating member is greater than the set speed are satisfied, the dead band width is adjusted, or instead of (b), the condition of (x) ' The dead band width can be adjusted when the condition or the condition (z) ′ is satisfied.
(13) When the brake force is held, the brake force control device gradually reduces the dead band width changed by the dead band width changing unit in a range where the vibration state maintains the holding control. The braking force control device according to any one of (2) to (12), including a dead band width gradually decreasing portion.
When the dead band width is unnecessarily increased, it is desirable to gradually reduce the dead band width within the range in which the holding control is maintained during the holding control in order to correct it.

(14) The content of at least one of the first rule and the second rule corresponding to at least one of the first rule change unit and the second rule change unit by the brake force control device. The brake force control device according to any one of (1) to (13), further including a change permission / prohibition unit that permits or prohibits a change based on the brake operation request.
For example, (i) when there is a request to quickly change the braking force, for example, when the absolute value | dPref | of the change gradient of the target value is larger than the set value dPth (| dPref |> dPth), (ii) a large brake When the force is required, for example, when the target value Pref is larger than the set value Pth (Pref> Pth), (iii) the absolute value | Pref−Pw | of the deviation between the target value of the brake force and the actual brake force is When the deviation is larger than the set deviation, for example, the change of the first rule or the second rule is prohibited, and (iv) when there is a request to gently change the braking force, for example, the absolute value of the change gradient of the target hydraulic pressure | dPref When | is smaller than the set value dPth (| dPref | <dPth), (v) When a large braking force is not required, for example, when the target hydraulic pressure Pref is smaller than the set value Pth (Pref <Pth), it is permitted. You can make it.
Specifically, when there is a request to operate the brake based on the slip state of the wheel (when start conditions such as anti-lock control, traction control, vehicle stability control, etc. are satisfied) When there is a request to operate based on the relative positional relationship (when start conditions such as cruising control and collision avoidance control are satisfied), when the operating force and operating speed of the brake operating member by the driver are large, It is desirable that changes are prohibited.
In addition, both the first rule and the second rule may be prohibited from being changed, or one of the changes may be prohibited.
(15) At least one of the first rule and the second rule corresponding to at least one of the first rule changing unit and the second rule changing unit by the brake force control device. (A) when the increase gradient of the target value is smaller than the set gradient, (b) when the deviation obtained by subtracting the actual braking force from the target value is smaller than the set deviation, and (c) the driver's A change permission unit that permits permission when one or more of a case where the operation speed of the brake operation member is smaller than the set speed and a case where (d) the traveling speed of the vehicle is equal to or less than the set speed are satisfied The braking force control device according to any one of (1) to (14).
When the increase gradient of the target value is smaller than the set gradient, when the deviation is small, when the driver's operation speed is small, when the traveling speed of the vehicle is small, the change of the first rule and the second rule is permitted. In these cases, it is considered that a smooth braking feeling is desired. In addition, it is considered that an uncomfortable feeling is felt by the operation sound generated from the brake force control mechanism.
In addition, it can be permitted when one or more of the conditions (a), (b), and (c) and the condition (d) are both satisfied.
(16) The brake is a hydraulic brake provided corresponding to a wheel of the vehicle and operated by a hydraulic pressure of a brake cylinder;
The hydraulic pressure control mechanism as the brake force control mechanism includes (i) (a) a power source that is actuated by supplying current, and a power type hydraulic pressure source that is driven by the drive source; and (b) the drive A drive source control hydraulic pressure control device including a drive source current control unit that controls an output hydraulic pressure of the power hydraulic pressure source by controlling a supply current to the source; and (ii) (c) a high pressure operation A hydraulic pressure source capable of outputting liquid, (d) one or more electromagnetic hydraulic pressure control valves capable of controlling the hydraulic pressure of the hydraulic pressure source, and (e) controlling a supply current to the electromagnetic hydraulic pressure control valve. The braking force according to any one of items (1) to (15), including at least one of a solenoid valve control-use hydraulic pressure control device including an electromagnetic valve current control unit that controls an output hydraulic pressure by Control device.
The electromagnetic hydraulic pressure control valve can be referred to as a linear control valve in which the differential pressure (and / or) opening degree thereof can be continuously controlled by continuous control of the amount of current supplied to the coil. Or a switch that can be switched between an open state and a closed state by ON / OFF control of the supply current (which can be simply referred to as an on-off valve).
(17) The brake is a hydraulic brake that is provided corresponding to each of the plurality of wheels of the vehicle and that is operated by the hydraulic pressure of the brake cylinder,
The brake cylinders of these multiple hydraulic brakes are each connected to a common passage,
The common cylinder is provided with a brake cylinder hydraulic pressure detecting device for detecting the brake cylinder hydraulic pressure as the brake force,
The hydraulic control mechanism as the brake force control mechanism includes an electromagnetic control valve provided between the common passage and each of the plurality of brake cylinders,
The vibration state detection device includes a sensor value use vibration state detection unit that detects the vibration state using a detection value by the brake cylinder hydraulic pressure detection device,
The plurality of electromagnetic controls when the second rule change unit does not improve the vibration state detected by the sensor value-based vibration state detection unit after the first rule is changed by the first rule change unit. Including a solenoid valve control rule changing unit for changing the contents of the valve control rules,
The brake force control device closes an electromagnetic control valve corresponding to at least one brake cylinder determined by a vibration state of hydraulic pressure among the plurality of brake cylinders according to the rule changed by the electromagnetic valve control rule changing unit. Thus, the brake force control device according to any one of (1) to (16), including a brake cylinder blocking portion that blocks the at least one brake cylinder from the common passage.
When a plurality of brake cylinder hydraulic pressures are controlled in common, the electromagnetic control valve provided between the common passage and each of the brake cylinders is opened according to the second rule.
On the other hand, when vibration due to reverse input occurs, the contents of the second rule are changed, and electromagnetic control provided between at least one brake cylinder and the common passage determined by the vibration state of the hydraulic pressure The valve is closed.
For example, the vibration state of each hydraulic pressure of each brake cylinder is actually detected to identify a brake cylinder with a large hydraulic pressure amplitude or a brake cylinder with a high hydraulic pressure change frequency. The control valve can be shut off. Also, without detecting the vibration state of each of the hydraulic pressures of the plurality of brake cylinders, the electromagnetic control valve corresponding to the brake cylinder (if known) that is likely to generate vibration (highly likely to be generated) is shut off. You can also. For example, when a part of a plurality of hydraulic brakes is a disc brake and the rest is a drum brake, it is known that the drum brake is more susceptible to vibration. Therefore, the electromagnetic control valve corresponding to the brake cylinder of the drum brake can be closed.
(18) The brake force control device according to (17), wherein the brake force control device includes a cutoff brake cylinder specifying unit that specifies at least one brake cylinder to be cut off from the common passage from the plurality of brake cylinders.
For example, if the electromagnetic control valves provided between the common passage and each of the brake cylinders are sequentially closed, and the change in the detected value of the brake cylinder hydraulic pressure detection device provided in the common passage is acquired, the hydraulic pressure A brake cylinder having a large vibration amplitude and a brake cylinder having a high change frequency can be identified.
(19) The brake is a hydraulic brake that is provided corresponding to each of the plurality of wheels of the vehicle and is operated by the hydraulic pressure of a brake cylinder,
A part of the plurality of hydraulic brakes is a disc brake that presses a friction member against a brake rotating body that rotates together with the wheel by the hydraulic pressure of the brake cylinder, and the part of the plurality of hydraulic brakes Is a drum brake that presses the friction member against the inner peripheral surface of the drum that rotates together with the wheel by the hydraulic pressure of the brake cylinder,
The brake cylinders of the plurality of hydraulic brakes are each connected to a common passage,
The common cylinder is provided with a brake cylinder hydraulic pressure detecting device for detecting the brake cylinder hydraulic pressure as the brake force,
The hydraulic control mechanism as the brake force control mechanism includes an electromagnetic control valve provided between the common passage and each of the plurality of brake cylinders,
The vibration state detection device includes a sensor value use vibration state detection unit that detects the vibration state using a detection value by the brake cylinder hydraulic pressure detection device,
The plurality of electromagnetic controls when the second rule change unit does not improve the vibration state detected by the sensor value-based vibration state detection unit after the first rule is changed by the first rule change unit. Including a solenoid valve control rule changing unit for changing the contents of the valve control rules,
The brake force control device shuts off a drum brake cylinder that closes an electromagnetic control valve corresponding to a brake cylinder of the drum brake among the plurality of brake cylinders according to a rule changed by the electromagnetic valve control rule changing unit. The brake force control device according to any one of (1) to (18), including a section.
If the brake cylinder of the drum brake is cut off from the common passage, vibration of the detected value by the brake cylinder hydraulic pressure detection device can be suppressed.
(20) A brake force control device for bringing a brake force of a brake for suppressing rotation of a vehicle wheel close to a target value,
A holding unit that holds the braking force when the braking force is inside a dead zone determined by the target value and the dead zone width;
An increase / decrease part for increasing or decreasing the braking force when the braking force is outside the dead zone;
A vibration state detection device that detects the state of vibration of the brake force based on the frequency at which the brake force changes from the inside to the outside of the dead zone;
A dead zone width changing device that changes the dead zone width based on a vibration state detected by the vibration state detection device, wherein the vibration state detected by the vibration state detection device reaches the frequency set to the stable side. And a brake force control apparatus comprising a dead band width gradually increasing portion that gradually increases the dead band width.
The technical feature described in any one of the items (1) to (19) can be employed in the braking force control device described in this item.
(21) a holding unit that holds the braking force when the braking force of the brake that suppresses the rotation of the wheels of the vehicle is inside the dead zone determined by the target value and the dead zone width;
An increase / decrease part for increasing or decreasing the braking force when the braking force is outside the dead zone;
A brake force control device including a dead zone changing device that changes the dead zone width based on a vibration state of the brake force,
The dead zone changing device is
A provisional dead band width setting unit for provisionally setting the dead band width;
A temporary vibration state of the brake force is estimated based on the frequency at which the braking force changes from the inside of the temporary dead zone determined by the temporary dead zone width set by the temporary dead zone setting unit and the target value to the outside. A vibration state detector;
A provisional dead band width gradually increasing unit that gradually increases the provisional dead band width until the frequency reaches the provisional stable side setting frequency, and the provisional dead band width gradually increasing unit A brake force control device characterized in that the dead band width that is gradually increased is set as the dead band width after the change.
The technical feature described in any one of the items (1) to (20) can be employed in the braking force control device described in this item.

It is a state which shows the action | operation (gradual increase of a dead zone width) state in the brake fluid pressure control apparatus which concerns on Example 1 of this invention. It is a brake fluid pressure circuit diagram of a fluid pressure brake system provided with a brake fluid pressure control device common to a plurality of embodiments of the present invention. (a) It is sectional drawing of the pressure increase linear control valve and pressure reduction linear control valve which are contained in the said brake fluid pressure circuit. (b) It is a map which shows the table showing the valve opening characteristic of the said pressure increase linear control valve. It is a conceptual diagram which shows the periphery of brake ECU contained in the said hydraulic brake system. It is a control block diagram of the brake ECU. It is a flowchart showing the hydraulic control actuator control program memorize | stored in the memory | storage part of brake ECU of the said hydraulic brake system. It is a figure which shows notionally the content of the control mode determination table memorize | stored in the said memory | storage part. It is a flowchart showing the hunting level detection program memorize | stored in the said memory | storage part. It is a flowchart showing the timer control program memorize | stored in the said memory | storage part. It is a flowchart showing the adaptive current change program memorize | stored in the said memory | storage part. It is a figure which shows notionally the state of the count of the said hunting level detection. It is a figure which shows notionally the state of the change of the adaptive current value accompanying the count-up of the said hunting level. It is a flowchart showing the reverse input determination program memorize | stored in the said memory | storage part. It is a flowchart showing the dead zone width change program memorize | stored in the memory | storage part of the brake fluid pressure control apparatus which concerns on Example 1 of this invention. It is a flowchart showing the dead zone width change program memorize | stored in the memory | storage part of the brake fluid pressure control apparatus which concerns on Example 2 of this invention. It is a figure which shows the relationship between the dead zone width increase amount memorize | stored in the said memory | storage part, and a reverse input level. It is a figure which shows notionally the brake ECU periphery of the brake fluid pressure control apparatus which concerns on Example 3 of this invention. It is a flowchart showing the temporary dead zone width acquisition program memorize | stored in the memory | storage part of the said brake ECU. It is a flowchart showing the dead zone width change program memorize | stored in the said memory | storage part. It is a flowchart showing the dead zone determination program memorize | stored in the memory | storage part of brake ECU of the brake fluid pressure control apparatus which concerns on Example 4 of this invention. It is a flowchart showing a part (dead zone width change in holding mode) of the dead zone determination program. It is a figure showing the dead zone determined in the said brake fluid pressure control apparatus. (a) It is a flowchart showing the prohibition flag ON / OFF program memorize | stored in the memory | storage part of brake ECU of the brake fluid pressure control apparatus which concerns on Example 5 of this invention. (b) It is a flowchart showing the dead zone width change program memorize | stored in the said memory | storage part. It is a flowchart showing the rear-wheel holding valve control program memorize | stored in the memory | storage part of brake ECU of the brake fluid pressure control apparatus which concerns on Example 6 of this invention. It is a figure showing another hydraulic brake circuit contained in the hydraulic brake system common to the several Example of this invention. It is a figure showing another hydraulic brake circuit contained in the hydraulic brake system common to the several Example of this invention. It is a figure showing another hydraulic brake circuit contained in the hydraulic brake system common to the several Example of this invention. It is a figure showing another hydraulic brake circuit contained in the hydraulic brake system common to the several Example of this invention. It is a figure showing another hydraulic brake circuit contained in the hydraulic brake system common to the several Example of this invention.

Hereinafter, a brake fluid pressure control device as a brake force control device according to an embodiment of the present invention will be described.
First, a hydraulic brake system common to brake hydraulic pressure control devices according to a plurality of embodiments of the present invention will be described.
The hydraulic brake system can be mounted on a hybrid vehicle, a plug-in hybrid vehicle, an electric vehicle, a fuel cell vehicle, an internal combustion drive vehicle, or the like. In hybrid vehicles, plug-in hybrid vehicles, electric vehicles, fuel cell vehicles, etc., since regenerative cooperative control is performed, the brake cylinder hydraulic pressure is set so that the total required braking torque is satisfied by the regenerative braking torque and the hydraulic braking torque. Is controlled. When the regeneration cooperative control is not performed, the brake cylinder hydraulic pressure is controlled so that the hydraulic braking torque becomes the total required braking torque. In any case, the total required braking torque is determined on the basis of the brake operation state by the driver or on the basis of the traveling state of the vehicle (wheel slip state: antilock control, traction control, vehicle (Stability control), a case where it is determined based on a relative position with respect to a preceding vehicle or a surrounding object (cruising control, collision avoidance control, etc.).
In this specification, when it is necessary to distinguish brake cylinders, hydraulic brakes, various electromagnetic on-off valves, which will be described later, and the like according to the positions of front, rear, left and right wheels, reference numerals (FL , FR, RL, RR), and representatively, or when there is no need to distinguish, it is described without any reference.

<Hydraulic brake circuit>
The hydraulic brake system includes a brake circuit shown in FIG.
Reference numerals 12 and 14 denote left and right front wheels, and reference numerals 16 and 18 denote left and right rear wheels. The left and right front wheels 12 and 14 are provided with disc brakes 22FL and 22FR as hydraulic brakes, and the left and right rear wheels 16 and 18 are provided with drum brakes 26RL and RR as hydraulic brakes. Each of the disc brakes 22FL and FR includes a brake cylinder 32, and presses the friction member against a rotating disc that rotates together with the wheels 12 and 14 by the hydraulic pressure of the brake cylinder 32, thereby suppressing the rotation of the wheel. 26RL and RR each include a brake cylinder 36, and the friction member is pressed against the inner peripheral surface of the rotating drum rotating together with the wheels 16 and 18 by the hydraulic pressure of the brake cylinder 36, thereby suppressing the rotation of the wheels. .
Reference numeral 50 denotes a brake pedal as a brake operation member, and reference numeral 52 denotes a master cylinder that generates hydraulic pressure by operating the brake pedal 50. A power hydraulic pressure source 54 includes a pump device 56 and an accumulator 58.
The master cylinder 52 is a dandem type equipped with two pressurizing pistons 62a, 62b. The front of the pressurizing pistons 62a, 62b is used as pressurizing chambers 64a, 64b, respectively. Connected.

  In the motive power hydraulic pressure source 54, the pump device 56 includes a pump 90 and a pump motor 92, and the hydraulic fluid is pumped up from the reservoir 94 by the pump 90 and is discharged and stored in the accumulator 58. The pump motor 92 is controlled so that the pressure of the hydraulic fluid stored in the accumulator 58 is within a predetermined setting range. For example, it can be started when the accumulator pressure becomes lower than the lower limit value of the setting range, and can be stopped when it reaches the upper limit value of the setting range.

On the other hand, the brake cylinders 32FL, FR of the left and right front wheels 12, 14 and the brake cylinders 36RL, RR of the left and right rear wheels 16, 18 are connected to the common passage 102 via individual passages 100FL, FR, RL, RR, respectively.
The individual passages 100FL, FR, RL, RR are respectively provided with holding valves (SHij: i = F, R, j = L, R) 103FL, FR, RL, RR, and brake cylinders 32FL, 32FR, 36RL, Pressure reducing valves (SRij: i = F, R, j = L, R) 106FL, FR, RL, RR are provided between the 36RR and the reservoir 94, respectively.
Also, the holding valve 103FL provided corresponding to the left front wheel 12 is a normally open electromagnetic on-off valve that is open when no current is supplied to the solenoid coil, and the remaining right front wheel 14, left rear wheel 16, holding valves 103FR, RL, and RR provided corresponding to the right rear wheel 18 are normally closed electromagnetic on-off valves that are closed when no current is supplied to the solenoid coil.
Further, the pressure reducing valves 106FL and FR provided corresponding to the left and right front wheels 12 and 14 are normally closed electromagnetic on-off valves, and the pressure reducing valves 106RL and RR provided corresponding to the left and right rear wheels 16 and 18 are normally open. This is an electromagnetic on-off valve.

In addition to the brake cylinders 32 and 36, a power hydraulic pressure source 54 is connected to the common passage 102 via a control pressure passage 110.
A pressure increasing linear control valve (SLA) 112 is provided in the control pressure passage 110, and a pressure reducing linear control valve (SLR) 116 is provided between the control pressure passage 110 and the reservoir 94. The hydraulic pressure in the common passage 102 is controlled by the control of the pressure-increasing linear control valve 112 and the pressure-decreasing linear control valve 116 (the output hydraulic pressure of the power hydraulic pressure source 64 is controlled and supplied to the common passage 102. ).
The pressure-increasing linear control valve 112 and the pressure-decreasing linear control valve 116 are both normally closed electromagnetic on-off valves that are in a closed state when no current is supplied to the solenoid coil, and the magnitude of the current supplied to the coil 126 is large. With this continuous control, the magnitude of the output hydraulic pressure is continuously controlled. The pressure-increasing linear control valve 112, the pressure-decreasing linear control valve 116, and the like constitute a fluid pressure control actuator 118.
As shown in FIG. 3 (a), each of the pressure-increasing linear control valve 112 and the pressure-reducing linear control valve 116 includes a seating valve including a valve element 120 and a valve seat 122, a spring 124, and a coil 126. The biasing force Fs of the spring 124 acts in a direction that causes the valve element 120 to approach the valve seat 122, and when the current is supplied to the coil 126, the driving force Fd causes the valve element 120 to move from the valve seat 122. Acts in the direction of separation. In addition, in the pressure-increasing linear control valve 112, the differential pressure acting force Fp corresponding to the pressure difference between the power hydraulic pressure source 64 and the common passage 102 acts in a direction to separate the valve element 120 from the valve seat 122, and the pressure-decreasing linear In the control valve 116, a differential pressure acting force Fp corresponding to the differential pressure between the common passage 102 (control pressure passage 110) and the reservoir 94 acts (Fd + Fp: Fs). In any case, by controlling the current supplied to the coil 126, the differential pressure acting force Fp is controlled, and the hydraulic pressure in the common passage 102 is controlled.
In FIG. 3B, the pressure-increasing linear control valve 112, which is the relationship between the supply current I to the coil 126 and the valve opening pressure (which can be considered as the relationship between the differential pressure and the valve opening current). The characteristics of FIG. 3 (b) shows that the valve opening current is small when the differential pressure across the front and rear is large.
The characteristics of the pressure-reducing linear control valve 116 are the same.

On the other hand, the master passages 66a and 66b are provided on the downstream side of the holding valves 103FR and FL of the individual passages 100FR and FL of the right front wheel 14 and the left front wheel 12, respectively (parts between the holding valves 103FR and FL and the brake cylinders 42FR and RL). ). The master passages 66a and 66b are directly connected to the brake cylinders 32FR and 32FL without being connected to the common passage 102.
Master shutoff valves (SMCFR, FL) 134FR, FL are provided in the middle of the master passages 66a, 66b, respectively. Master shut-off valves 134FR and FL are normally open electromagnetic on-off valves.
A stroke simulator 140 is connected to the master passage 66b via a simulator control valve 142. The simulator control valve 142 is a normally closed electromagnetic on-off valve.

The hydraulic brake system includes a brake ECU 148 shown in FIG. The brake ECU 148 mainly includes a computer including an execution unit (CPU) 150, an input / output unit 151, a storage unit 152, and the like. The input / output unit 151 includes a brake switch 158, a stroke sensor 160, a master cylinder pressure sensor. 162, an accumulator pressure sensor 164, a brake cylinder pressure sensor 166, a wheel speed sensor 170, and the like are connected.
The brake switch 158 is a switch that turns from OFF to ON when the brake pedal 50 is depressed.
The stroke sensor 160 detects an operation stroke (STK) of the brake pedal 50. In the present hydraulic brake system, two sensors are provided, and similarly, an operation stroke (from the reverse end position) of the brake pedal 50 is provided. ) Is detected. As described above, the stroke sensor 160 has two systems, and even if one of the two sensors breaks down, the other can detect the stroke.
The master cylinder pressure sensor 162 detects the hydraulic pressure (PMC) in the pressurizing chamber 64b of the master cylinder 52, and is provided in the master passage 66b.
The accumulator pressure sensor 164 detects the pressure (PACC) of the hydraulic fluid stored in the accumulator 58, and detects the hydraulic pressure upstream of the pressure-increasing linear control valve 112.
The brake cylinder pressure sensor 166 detects the hydraulic pressure (PWC) of the brake cylinders 32 and 36 and is provided in the common passage 102. Since the brake cylinders 32 and 36 and the common passage 102 are communicated with each other in the open state of the holding valve 103, the hydraulic pressure in the common passage 102 can be set to the hydraulic pressure of the brake cylinders 32 and 36. The detected value by the brake cylinder pressure sensor 166 is used as the hydraulic pressure downstream of the pressure-increasing linear control valve 112 and upstream of the pressure-reducing linear control valve 116, and the differential pressure before and after is obtained.
Wheel speed sensors 170 are provided corresponding to the left and right front wheels 12, 14 and the left and right rear wheels 16, 18, respectively, and detect the rotational speed of the wheels. Further, the traveling speed of the vehicle is acquired based on the rotational speed of the four wheels.
Further, the input / output unit 151 includes all electromagnetic open / close valves included in the brake circuit, such as the pressure increasing linear control valve 112, the pressure reducing linear control valve 116, the holding valve 103, the pressure reducing valve 106, the master shutoff valve 134, the simulator control valve 142, and the like. A coil (hereinafter simply referred to as all electromagnetic on-off valves), a pump motor 92, and the like are connected via a drive circuit (not shown).
Furthermore, the storage unit 152 stores various programs, tables, and the like.
In this hydraulic brake system, it is considered that the hydraulic pressure control mechanism as the brake force control mechanism is constituted by the pressure increasing linear control valve 112, the pressure reducing linear control valve 116, etc., or the pressure increasing linear control valve 112, the pressure reducing linear control valve 116, etc. It can be considered that the hydraulic control mechanism is configured by the linear control valve 116, the holding valve 103, the pressure reducing valve 106, and the like.

The operation of the hydraulic brake system configured as described above will be described.
<Control of hydraulic pressure control mechanism>
When there is an operation request for the hydraulic brakes 22, 26, the required hydraulic braking torque is acquired, and a target value of the brake cylinder hydraulic pressure that can realize the required hydraulic braking torque is obtained. Then, the hydraulic pressure control actuator 118 is controlled in the closed state of the master shut-off valve 134, the open state of the holding valve 103, and the closed state of the pressure reducing valve 106 so that the actual brake cylinder hydraulic pressure reaches the target hydraulic pressure.
As described above, the required hydraulic braking torque is acquired based on the total required braking torque. When the required hydraulic braking torque is acquired based on the operation state of the brake pedal 50 of the driver, the required hydraulic braking torque is acquired based on the slip state of the wheel. In some cases, it is acquired based on the relative positional relationship with surrounding objects. The operation state of the brake pedal 50 of the driver is acquired based on the detection value of the stroke sensor 160, the detection value of the master cylinder pressure sensor 166, and the like, and the slip state of the wheel is acquired based on the detection value of the wheel rotation sensor 170. The
In addition, when antilock control, traction control, or the like is performed, the holding valve 103 and the pressure reducing valve 106 are each opened and closed.

FIG. 5 is a functional block diagram showing an outline of the hydraulic pressure control executed by the brake ECU 148. The hydraulic pressure control actuator 118 as a control target is controlled by the feedforward control unit 180 and the feedback control unit 182. Further, the target value of control is the target hydraulic pressure Pref of the brake cylinder, and the output is the output hydraulic pressure Pw by the brake cylinder hydraulic pressure sensor 166.
The feedforward control unit 180 calculates a feedforward pressure increase current IFSLA and a feedforward pressure reduction current IFSLR based on the target hydraulic pressure Pref. The feedback control unit 182 also feeds back a feedback boost current as a current for bringing the deviation error, which is a value obtained by subtracting the actual brake fluid pressure Pw detected by the brake cylinder fluid pressure sensor 166 from the target fluid pressure Pref, to zero. IBSLA and feedback decompression current IBSLR are calculated. Thus, the control of the brake ECU 148 in the present hydraulic brake system includes both feedforward control and feedback control.

The supply current to each of the pressure-increasing linear control valve 112 and the pressure-decreasing linear control valve 116 of the hydraulic control actuator 118 is determined according to the execution of the linear control valve control program represented by the flowchart of FIG. This program is executed every predetermined control cycle time.
In step 1 (hereinafter abbreviated as S1. The same applies to other steps), it is determined whether or not there is an operation request for the hydraulic brakes 22 and 26. If there is no operation request, in S6, The current supplied to the coil 126 of the pressure-increasing linear control valve 112 and the coil 126 of the pressure-decreasing linear control valve 116 is set to zero.
If there is an operation request, the target hydraulic pressure Pref is determined in S2 as described above, and the brake hydraulic pressure Pw is detected by the brake cylinder hydraulic pressure sensor 166 in S3, and the brake hydraulic pressure is determined from the target hydraulic pressure Pref. A value obtained by subtracting Pw is obtained as a deviation error (Pref-Pw). In S4, the control mode is determined based on the actual brake cylinder hydraulic pressure Pw, the target hydraulic pressure Pref, and the dead zone width ΔB. In S5, it is detected whether the determined control mode is the pressure increasing mode, the pressure reducing mode, or the holding mode.
If the determined control mode is the holding mode, the supply current to the pressure-increasing linear control valve 112 and the pressure-decreasing linear control valve 116 is set to 0 in S6.
If it is in the pressure increasing mode, the supply current ISLA to the pressure increasing linear control valve 112 is determined in S7. In this case, the supply current ISLR to the pressure-reducing linear control valve 116 is zero.
If the pressure reducing mode is set, the supply current ISLR to the pressure reducing linear control valve 116 is determined in S8. In this case, the supply current ISLA to the pressure-increasing linear control valve 112 is set to zero.

The control mode is determined as shown in FIG. 7 in the present hydraulic brake system. The dead band width ΔB may be changed as will be described later, but a value determined (stored) at that time is used. The determined (stored) value may be a predetermined value (default value).
Based on the target hydraulic pressure Pref and the dead band width ΔB, the pressure reduction threshold value Pthd and the pressure increase threshold value Pthu
Pthd = Pref + ΔB / 2
Pthu = Pref−ΔB / 2
Is determined.
When the actual brake cylinder hydraulic pressure Pw is greater than the pressure reduction threshold Pthd, the pressure reduction mode is set. When the actual brake cylinder hydraulic pressure Pw is less than the pressure increase threshold Pthu, the pressure increase mode is set. Is set.
As described above, when the dead zone width ΔB is large, the opportunity to set the pressure increasing mode and the pressure reducing mode is reduced, and the opportunity to operate the pressure increasing linear control valve 112 and the pressure reducing linear control valve 116 is reduced. .
In this hydraulic brake system, the threshold value for switching from the holding mode to the depressurization mode is the same as the threshold value for switching from the depressurization mode to the holding mode. The threshold value when switching to the pressure mode and the threshold value when switching from the pressure increasing mode to the holding mode are the same.

The supply current to the pressure-increasing linear control valve 112 and the pressure-decreasing linear control valve 116 is the sum of the feedforward current (IFSLA, IFSLR) from the feedforward control unit 180 and the feedback current (IBSLA, IBSLR) from the feedback control unit 182. Desired.
The feedforward boost current IFSLA for the booster linear control valve 112 is given by the formula IFSLA = (KF · dPref + Iadj-ap + ΔI)
The feedback boost current IBSLA is determined according to the formula IBSLA = f (KB · error)
Determined according to.
And these sums ISLA = IFSLA + IBSLA
Is the supply current ISLA to the pressure-increasing linear control valve 112.

The value Iadj-ap of the supply current IFSLA in the feedforward control unit 180 is a valve opening current determined according to the valve opening current determination table represented by the map of FIG.
The valve opening current Iadj-ap is a value that decreases as the differential pressure ΔP before and after the pressure-increasing linear control valve 112 increases, and when the valve opening current Iadj-ap is supplied to the coil 126, The sum of the differential pressure acting force and the electromagnetic driving force is in balance with the elastic force of the spring 124.
The value (KF · dPref) is a current necessary to keep the pressure-increasing linear control valve 112 open until the hydraulic pressure in the brake cylinder approaches the target hydraulic pressure Pref. The coefficient KF is a control gain in the feedforward control.

The adaptive current ΔI is a correction current determined based on the vibration state of the brake cylinder hydraulic pressure. In this hydraulic brake system, the magnitude obtained by adding the correction current, which is the adaptive current ΔI, to the valve opening current Iadj-ap obtained according to the table shown in FIG. 3B is the actual operation start current of the linear control valve. Thus, the adaptive current ΔI is determined. Although the table is uniformly determined, the operation start current varies depending on the actual state of the pressure-increasing linear control valve 112 (the magnitude of the elastic force of the spring, the operating environment, etc.). For this reason, even when the valve opening current Iadj-ap determined according to the table is added, there are cases where the switching is actually switched to the open state and switching may not be performed, and the response becomes sensitive or a response delay occurs. Therefore, in the present hydraulic brake system, when the current obtained by adding the adaptive current ΔI to the valve opening current Iadj-ap obtained according to the table is supplied, the adaptive current is actually switched from the closed state to the open state. ΔI is determined based on the vibration state of the brake cylinder hydraulic pressure. In other words, when the change frequency of the brake cylinder hydraulic pressure is high, it is considered that the operation start current is too large. Therefore, the adaptive current ΔI is reduced (set to a negative value), and the change delay of the brake cylinder hydraulic pressure is delayed. If it is larger, the operation starting current is considered to be too small, so that the adaptive current is increased (a positive value).
Thus, after the feed forward current is increased stepwise by the operation start current, it is gradually increased according to the change in the target hydraulic pressure with a gradient corresponding to the feed forward control gain.
The same applies to the current supplied to the coil of the pressure-reducing linear control valve 116.
In the present hydraulic brake system, a brake control unit that uses current control includes a part that stores, executes, and the like the linear control valve control program represented by the flowchart of FIG. 6 of the brake ECU 148. The brake force control unit using current control is also a solenoid valve current control unit. Further, a hydraulic pressure control device using the hydraulic valve control, the hydraulic pressure control actuator 118, the electromagnetic valve current control unit, and the like constitute an electromagnetic valve control utilization hydraulic pressure control device.

<Detection of vibration state of brake cylinder hydraulic pressure>
The vibration state of the brake cylinder hydraulic pressure is represented by a hunting level in the hydraulic brake system. The hunting level is a value representing the strength of the hunting tendency, and when the hunting level is high, the possibility that hunting occurs is high.
In the present hydraulic brake system, the hunting level becomes larger than the depressurization threshold Pthd, the interval from when the brake cylinder hydraulic pressure becomes smaller than the pressure increase threshold Pthu in FIG. It is expressed as the number of times when the interval from when the pressure becomes smaller than the pressure increase threshold value Pthu is shorter than the set time. It can be assumed that the greater the number of times that the hydraulic pressure change interval time is shorter, the higher the hunting tendency (the vibration state of the brake cylinder hydraulic pressure).
When the brake cylinder hydraulic pressure becomes smaller than the pressure increase threshold value Pthu, the holding mode is switched to the pressure increasing mode, and the pressure increasing linear control valve 112 is switched from the closed state to the open state. Further, when the brake cylinder hydraulic pressure becomes larger than the depressurization threshold value Pthd, the hold mode is switched to the depressurization mode, and the depressurization linear control valve 116 is switched from the closed state to the open state. Therefore, the brake cylinder hydraulic pressure change interval corresponds to the operation interval of the pressure increasing linear control valve 112 and the pressure reducing linear control valve 116.
Further, the vibration state of the brake cylinder hydraulic pressure and the hunting level do not always correspond. When the pressure increase threshold value Pthu and the pressure reduction threshold value thd are fixed values, the hunting level is the same if the vibration state of the brake cylinder hydraulic pressure is the same, but the pressure increase threshold value Pthu and the pressure reduction threshold value are the same. If the value Pthd is set to a variable value to be a large value, the hunting level may be reduced even if the vibration state of the brake cylinder hydraulic pressure is the same. In this case, it is apparent that the hunting tendency is reduced and the vibration state is improved. Further, since the hunting tendency is reduced, even if the vibration state of the brake cylinder hydraulic pressure is not improved, the operating frequency of the pressure increasing linear control valve 112 and the pressure reducing linear control valve 116 is lowered. Hereinafter, in the present specification, these cases may be referred to as improved hunting tendency without distinction.
The hunting level is detected according to the execution of the hunting level detection program represented by the flowchart of FIG. FIG. 11 shows a state where the hunting level is actually detected according to the execution of this program.

When the brake cylinder hydraulic pressure Pw becomes larger than the depressurization threshold Pthd before the elapsed time from when the brake cylinder hydraulic pressure Pw becomes smaller than the pressure increase threshold Pthu reaches the threshold A (time) ( When the hunting level CH is increased by 1 and the brake cylinder hydraulic pressure Pw becomes smaller than the pressure increase threshold value Pthu before the threshold value B is reached (when the holding mode is switched to the pressure reduction mode) ( 1) when the holding mode is switched to the pressure increasing mode. When the fluid pressure change interval time is shorter than the set time (time A, time B), the hunting level CH is incremented by 1. Also, before the time reaches the threshold value C, the pressure reduction threshold value Pthd is once exceeded. If a predetermined reset condition is satisfied, including that it has not increased (the decompression mode has not been set), the hunting level CH is reset and the time is returned to the threshold value B (A < B <C).
The timer for measuring time is reset every time the pressure increasing mode is set (the count value of the timer counter CT is reset to 0).
Note that the hunting tendency can be detected based on the point in time when the brake cylinder hydraulic pressure Pw becomes larger than the pressure reduction threshold value Pthd. In this case, the hunting tendency can be detected in the same manner.

Control of the timer (counting by the timer counter CT) is performed according to the execution of the timer control program represented by the flowchart of FIG.
In S11, it is determined whether or not the hydraulic control actuator 118 is under control. The timer is controlled during the control of the hydraulic pressure control actuator 118 (also the detection of the hunting level). Therefore, when the control is not being performed, the determination in S11 is NO, and the count value of the timer counter CT is set to 0 in S12.
During the control of the hydraulic pressure control actuator 118, the timer counter CT is incremented in S13, but when the brake cylinder hydraulic pressure becomes smaller than the pressure increase threshold value Pthu (the mode is switched from the holding mode to the pressure increase mode). If YES, the determination in S14 is YES, and the timer counter CT is reset to 0 in S15.
Then, until the pressure mode is switched from the holding mode, that is, while the pressure increasing mode is set, while the holding mode is set, while the pressure reducing mode is set, Since the determination in S14 is NO, it is determined in S16 whether or not the time corresponding to the count value of the timer counter CT has reached time C (threshold value C). Before reaching the threshold value C, the count value of the timer counter CT is increased in S13. When the threshold value C is reached, the determination in S16 is YES, and the count value of the timer counter CT is reset to a value corresponding to the time B (threshold value B) in S17.

The hunting level is detected using this timer, and is detected during the control of the hydraulic control actuator 118.
In the flowchart of FIG. 8, in S28, it is determined whether or not the change gradient (change amount with respect to time) of the target hydraulic pressure Pref is equal to or greater than the set gradient dPs. If it is equal to or greater than the set gradient dPs, the hunting level CH is set to 0 in S29. In this case, the adaptive current ΔI is set to 0 as will be described later.
When the change gradient of the target hydraulic pressure Pref is smaller than the set gradient dPs, S30 and subsequent steps are executed. In S30 to 37, the hunting level CH is counted, and in S38 and after, it is determined whether or not the reset condition for the hunting level CH is satisfied.

In S30 and 31, it is determined whether or not the count value of the timer counter CT is substantially 0. If it is approximately 0, the value of the hunting level CH at that time is stored. In S32, it is determined whether or not the time (elapsed time) corresponding to the count value of the timer counter CT has reached time (threshold value) A. Before reaching the threshold value A, it is determined in S33 whether or not the actual brake cylinder hydraulic pressure Pw has exceeded the pressure reduction threshold value Pthd (whether or not the holding mode has been switched to the pressure reduction mode). When switched to the decompression mode, the hunting level CH is counted up by 1 in S34. However, if the decompression mode is not set before the threshold A is reached, the count value is increased. There is no.
After reaching the threshold value A, S33 and S34 are not executed, and it is determined in S35 whether or not the count value of the timer counter CT has reached a value corresponding to the threshold value B. Before reaching the time corresponding to the threshold value B, whether or not the actual brake cylinder hydraulic pressure Pw has become smaller than the pressure increase threshold value Pthu (switched from the holding mode to the pressure increase mode) in S36. Is determined and the determination in S36 is YES, the count value of the hunting level CH is incremented by 1 in S37. When the pressure increasing mode is not set, the count value is not counted up.
As described above, in the present hydraulic brake system, the threshold value is changed when the holding mode is switched to the depressurization mode before the elapsed time after switching from the holding mode to the pressure increasing mode reaches the threshold value A. When the holding mode is switched to the pressure increasing mode before reaching B, the hunting level CH is counted up. Also, the count is incremented when the pressure increasing mode is switched to the holding mode before the threshold A is reached.

When the threshold value B is reached, S38 and subsequent steps are executed. In S38, it is determined whether or not the current hunting level CH is the same as the hunting level CH stored in S31. If they are the same, the hunting level CH has never been counted up before the threshold value B is reached, and it can be seen that the hydraulic pressure change interval is large. In this case, in S39, it is determined whether or not the count value of the timer counter CT is substantially a value corresponding to the threshold value B. If it is a value corresponding to the threshold value B, in S40, The brake cylinder hydraulic pressure is detected by the brake cylinder hydraulic pressure sensor 166. Next, in S41, 42, the brake cylinder hydraulic pressure is detected when it is substantially the threshold value C, and the hydraulic pressure when the threshold value B is substantially reached and the threshold value C when the threshold value C is substantially reached in S43. It is determined whether or not the absolute value of the difference from the hydraulic pressure (the amount of change in hydraulic pressure during the time from the threshold value B to the threshold value C) is smaller than the set amount α. If the absolute value of the change amount of the hydraulic pressure in the time period from the threshold value B to the threshold value C (within the set time) is smaller than the set amount α, it is assumed that the reset condition is satisfied in {| ΔPw | <α}. The count value of the hunting level CH is set to 0 in S44. It is considered that the change in the brake cylinder hydraulic pressure was small and the detection of the tendency to hunting was wrong.
Thus, when the hunting level CH is 1 or more, the hydraulic pressure change interval is short and it can be assumed that there is a hunting tendency. However, when a hunting tendency is detected, a response delay is detected. Whether or not has occurred is detected. If a response delay is detected, the hunting level CH is set to 0, assuming that the reset condition is satisfied.
In the present hydraulic brake system, a vibration state detection device is configured by a portion that stores, executes, and the like a hunting detection program represented by the flowchart of FIG. 8 of the brake ECU 148. The vibration state detection device is also a dead-zone-use vibration state detection unit and a sensor value-based vibration state detection unit.
The method for counting the hunting level is not limited to the method in the present hydraulic brake system. If the actual brake cylinder hydraulic pressure does not exceed the depressurization threshold before reaching the threshold B, the hunting level can be reset.

<Change of rules (first rule) for determining supply current amount>
The adaptive current ΔI is determined according to the hunting level. For example, as shown in FIG. 12, when the hunting level CH is large, the absolute value of ΔI is made larger than when it is small. When the hunting level CH is large, the adaptive current ΔI is a negative and large value than when it is small. By reducing the feedforward current, the operation start timing of the pressure-increasing linear control valve 112 is delayed.
When the hunting level CH is detected in the manner shown in FIG. 11, the hunting level CH does not become a negative value, but when a response delay is detected, the hunting level CH is set to (−1). If counted, the hunting level CH may be a negative value. However, since the response delay is not related to the implementation of the present invention, the description thereof is omitted.

As shown in FIG. 12, when the hunting level CH is between 0 and +1, the appropriate current (correction value) ΔI is set to 0. A dead zone is provided in the hunting level CH (responsiveness level) for changing the current, and it is possible to avoid changing the supply current when it is unnecessary.
Further, a lower limit (negative) is determined for the adaptive current ΔI. Even if the hunting level CH becomes larger than the set value m, the adaptive current ΔI is not made smaller than the lower limit value. The feedforward current is prevented from becoming too small.
The adaptive current ΔI is determined according to the flowchart of FIG.
In S51, it is determined whether or not the hunting level CH is greater than a set value n. n is a hunting level CH representing the upper limit value of the dead zone, and is 1 in the present hydraulic brake system. It is determined whether it belongs to the dead zone of the hunting level CH. If it is larger than the set value n and does not belong to the dead zone, the adaptive current ΔI is expressed by the equation ΔI = −Δ · (H−n) in S52.
As required. Here, Δ is a reference unit for determining the adaptive current, and a value obtained by multiplying Δ by (H−n) is the adaptive current ΔI. In S53, it is determined whether or not the adaptive current ΔI is smaller than the lower limit value Limit (negative value). If smaller, the adaptive current ΔI is set to the lower limit value Limit in S55.

If the hunting level CH is smaller than the set value n, that is, if it belongs to the dead zone, the adaptive current ΔI is set to 0 in S55.
As described above, in the hydraulic brake system, the magnitude of the adaptive current ΔI is changed according to the hunting level CH. The rule is changed depending on whether the hunting level CH is greater than the set value n or less than the set value n. The rule for determining the supply current amount (feed forward current) to the pressure-increasing linear control valve 112 corresponds to the first rule, and the first rule is changed based on the hunting level CH.
The amount of current supplied to the pressure-reducing linear control valve 116 is similarly determined and changed in the same manner.
In the present hydraulic brake system, the first rule changing unit is configured by a part for storing, executing, etc. the adaptive current determination program represented by the flowchart of FIG. 10 of the brake ECU 148. The first rule change unit is also a current amount determination rule change unit.

In the present hydraulic brake system, the feedforward current is changed (the rule for determining the feedforward current is changed) by setting the value of the adaptive current ΔI to a value corresponding to the hunting level CH. However, it is also possible to change the feedforward current (change the feedforward current determination rule) by changing the feedforward control gain.
In the hydraulic brake system, the feedforward current is changed and the feedback current is not changed. However, the feedback current can also be changed. For example, the feedback control gain can be changed.

<Determination of vibration caused by reverse input>
In this way, the adaptive current ΔI is determined according to the hunting level CH. When the hunting level CH is large, the current at the start of operation (Iadj-ap + ΔI) to the pressure-increasing linear control valve 112 is greater than the actual braking. Even if the cylinder hydraulic pressure (differential pressure before and after) is the same, it is reduced. Therefore, it becomes possible to improve the hunting tendency.
However, if the hunting tendency is not improved even if the adaptive current ΔI is set to the lower limit value Limit and the supply current to the pressure-increasing linear control valve 112 is reduced, the cause of the hunting tendency is the control side (hydraulic pressure control actuator 118) and not the hydraulic brakes 22 and 26 (output side). For example, the vibration caused by the eccentric mounting of the drum of the drum brake 26, the unevenness of the disc rotor of the disc brake 22, the adhering of foreign matter or rust to the drum or disc, etc. Even if the current supplied to 118 is reduced, it is difficult to be affected and the hunting tendency is hardly improved. Thus, the vibration caused by the output side (hydraulic brake side) is referred to as the vibration caused by the reverse input.
That is, if the adaptive current ΔI is set to the lower limit value Limit, it is considered that most vibrations caused by the control side are suppressed. On the other hand, if the hunting tendency does not improve (for example, the hunting level count-up speed does not slow down) even if the adaptive current ΔI is reduced until it reaches the lower limit value Limit, the vibration is caused by the cause on the output side. Conceivable. In the present hydraulic brake system, the fact that the adaptive current ΔI is set to the lower limit value Limit corresponds to the fact that the content of the current amount determination rule has been changed to the set content.

A flowchart showing the reverse input determination program is shown in FIG. This program is executed at predetermined time intervals.
In S80, it is determined whether or not the adaptive current ΔI (negative value) is less than or equal to the lower limit value Limit (negative value). If it is larger than the lower limit value Limit, the reverse input flag is turned OFF in S81. As shown in FIG. 12, when the hunting level CH is equal to or higher than the set value m, the adaptive current ΔI is set to the lower limit value Limit, and while the hunting level CH is smaller than the set value m, the determination in S80 is NO. S80 and 81 are repeatedly executed.
When the hunting level CH becomes the set value m or more and the adaptive current ΔI becomes the lower limit value Limit or less, the determination in S80 is YES, and in S82, it is determined whether or not the first set time has elapsed. If the first set time has not elapsed, in S83, the hunting level CH, the count value of the timer, etc. are read and stored.
S80 to 83 are executed until the elapsed time after the adaptive current ΔI becomes lower than the lower limit value Limit reaches the first set time, and the hunting level CH is read, but the first set time is reached. If so, it is determined in S84 whether or not the hunting tendency has improved. For example, when the count-up speed of the hunting level CH becomes slower than the count-up speed before the adaptive current ΔI reaches the lower limit value Limit, the hunting level CH is not counted up at all during the first set time. It is determined that the situation has improved.
If it is determined that the hunting tendency has improved, it is considered that the input is not reverse input, and thus the reverse input flag is turned OFF in S81.
On the other hand, if the hunting tendency does not improve, it is considered that the vibration is caused by reverse input, and therefore the reverse input flag is turned ON in S85.

The count-up speed of the hunting level CH before the adaptive current ΔI reaches the lower limit value Limit can be obtained from, for example, the sum of the hunting level CH and the count value of the timer until the lower limit value Limit is reached. The count-up speed of the hunting level CH is acquired in advance and stored.
Further, when comparing the count-up speeds before and after the adaptive current ΔI reaches the lower limit value Limit, the average count-up speeds may be compared with each other or the times with the shortest change intervals may be compared. Any method is acceptable.
Further, the first set time is set to a length capable of detecting a hunting tendency in order to compare the count-up speeds. For example, the first set time can be set to be longer than the time during which the wheel makes one rotation. In the case of vibration caused by reverse input, the brake cylinder hydraulic pressure vibrates with the change in the case where the wheel makes one revolution as one cycle, so if the vibration for the time required for one revolution is detected, the count-up speed is acquired. (To obtain a hunting tendency).
The first set time may be a fixed value or a variable value. For example, it can be determined based on the count-up speed before the adaptive current ΔI reaches the lower limit value Limit. If the hunting level is not counted up during the first set time, the length can be determined so that the count-up speed is slower than before the adaptive current ΔI reaches the lower limit Limit.

  In this hydraulic brake system, the dead band width ΔB is increased when vibration due to reverse input is detected. The dead band width ΔB represents the content of the rule (second rule) for determining the pressure increasing mode, the holding mode, and the pressure reducing mode, and the content of the second rule is changed by changing the dead band width ΔB. Will be. If the dead band width ΔB is increased, the operation interval time of the hydraulic pressure control actuator 118 can be extended. In the following examples, specific modes for increasing the dead zone width ΔB will be described.

<Dead band width change 1>
In the first embodiment, the dead zone width is gradually increased until the vibration state reaches the stable side setting state.
The stable side set state refers to a state in which the increase amount of the hunting level during the second set time is smaller than the threshold value β. The threshold value β can be set to a small value such as 1 or 2, for example, and the second set time is a length of time during which a hunting tendency can be acquired and is the same length as the first set time. Can do. Further, it may be a fixed value or a variable value.
FIG. 14 is a flowchart showing the dead zone change program. The dead band changing program is executed every predetermined control cycle time.
In S90, it is determined whether or not the reverse input flag is ON. If it is OFF, S91 and subsequent steps are not executed.
If the reverse input flag is ON, initial setting is performed in S91 and S92. In S91, it is determined whether or not the initial setting has been completed. If the initial setting has not been completed, the dead band width ΔB at that time is increased by ΔBH, and the hunting level CH at that time is read and set to CH (0). The
ΔB ← ΔB + ΔBH
n ← 0
CH (0) ← CH
The dead band width {dead band width when determining the control mode} used in the control is actually changed, and the changed dead band width is stored.
ΔBH is a unit amount when the dead zone width ΔB is gradually increased in order to obtain an appropriate dead zone width, and is a smaller value than the dead zone width ΔB.

In S93, it is determined whether or not the elapsed time from when the dead band width ΔB is increased by ΔBH has reached the second set time. The determination is NO before the second set time has elapsed.
Next, when this routine is executed, since the initial setting is completed, S90, 91, and 93 are repeatedly executed. In the meantime, when the second set time elapses, the determination in S93 is YES, and in S94, the hunting level CH is read and set to the current value.
n ← n + 1
CH (n) ← CH
When S94 is first executed, n = 1 and the current value is CH (1).
In S95, it is determined whether or not a value obtained by subtracting the previous value CH (0) from the current value CH (1) is smaller than the threshold value β.
CH (1) −CH (0) <β
If the increase amount of the hunting level CH until the second set time elapses is equal to or greater than the threshold value β, the stable side set state has not been reached. In S96, the dead band width ΔB is further increased by ΔBH. (ΔB ← ΔB + ΔBH), and a timer (a timer for detecting that the second set time has elapsed) used in this program is reset.

Next, when this routine is executed, S90, 91 and 93 are similarly executed. If the second set time elapses while S90 to 93 are repeatedly executed, the determination in S93 is YES, and whether the value obtained by subtracting the previous value from the current value is smaller than the threshold value β in S94 and 95. It is determined whether or not {CH (2) −CH (1) <β}. If the increase amount of the hunting level CH until the second set time elapses is equal to or greater than the threshold value β, the dead band width ΔB is increased by the set amount ΔBH and the timer is reset in S96 and 97. .
Thereafter, the dead band width ΔB is gradually increased by ΔBH until the increase amount of the hunting level CH until the second set time elapses becomes smaller than the threshold value β.
S90, 91, 93 or S90, 91, 93 to 97 are repeatedly executed. Over time, the amount of increase in the hunting level within the second set time becomes smaller than the threshold value β, and the expression CH (n) −CH (n−1) <β
Is satisfied, the determination in S95 is YES, and the initial value is cleared in S98.
At the present time, the dead zone width ΔB (the current value and the dead zone width obtained in the immediately preceding S96) is stored. Since the vibration state acquired by executing the hunting level detection program has reached the stable side setting state, the dead band width ΔB is not gradually increased thereafter. The dead band width ΔB obtained in S96 is the changed (increased) dead band width (current value).
In addition, if the hunting level is reset before the second set time elapses, the current value of the hunting level is 0. Therefore, the value obtained by subtracting the previous value from the current value is smaller than 0. Value and the determination in S95 is YES.
Thus, when the hunting tendency is suppressed, the determination in S84 of the reverse input determination program is YES, and in S81, the reverse input flag is turned OFF.
Further, the determination in S90 is NO in the dead band changing program, and S91 and subsequent steps are not executed. By executing this program, the dead band width ΔB is not further increased.

For example, as shown in FIG. 1, when the dead band width ΔB is increased by ΔBH, the pressure increase threshold value Pthu is
Pthu = Pref− (ΔB + ΔBH) / 2
The decompression threshold value Pthd is
Pthd = Pref + (ΔB + ΔBH) / 2
It is said.
Thus, the pressure increase threshold value Pthu is reduced and the pressure reduction threshold value Pthd is increased, so that the brake cylinder hydraulic pressure Pw is unlikely to exceed the pressure increase threshold value Pthu and the pressure reduction threshold value Pthd.
However, if the hunting tendency is not improved sufficiently, it is further increased by ΔBH. The pressure increase threshold Pthu is
Pthu = Pref− (ΔB + ΔBH) / 2−ΔBH / 2
The decompression threshold value Pthd is
Pthd = Pref + (ΔB + ΔBH) / 2 + ΔBH / 2
It is said.
When the dead zone width ΔB is increased twice to improve the hunting tendency, the dead zone width is changed (stored) to a value larger by 2 × ΔBH than the dead zone width ΔB before the change. Thereafter, the hydraulic pressure control actuator 118 is controlled based on the changed dead band width.
In this embodiment, since the dead band width ΔB is gradually increased so that the vibration state reaches the stable side set state, the changed dead band width can be set to an appropriate size.

Thus, by increasing the dead zone width, the increase amount of the hunting level CH within the second set time is made smaller than the threshold value β, and the stable side set state is set. When the count-up value of the hunting level CH within the second set time is smaller than the threshold value β (0 or 1), it can be considered that the hunting tendency is small, and the adaptive current ΔI is It can be considered that the hunting tendency has been improved before the lower limit Limit is reached (when it is determined that the hunting tendency is caused by reverse input).
Strictly speaking, even if the dead zone width is increased, the actual vibration state of the brake cylinder hydraulic pressure is not improved, but the vibration state (hunting tendency) represented by the hunting level has been improved. The control hunting at 118 can be considered improved. That is, it cannot be improved by changing the first rule, but improved by changing the second rule.
As described above, in the present embodiment, the second rule changing unit is configured by the part that stores the flowchart of FIG. The second rule changing unit is also a dead zone changing unit, a dead zone gradually increasing unit, and a non-improvement changing unit.

The dead band width ΔB can be increased by a predetermined set value ΔBs (ΔB ← ΔB + ΔBs) regardless of whether the hunting tendency is improved or not.
Further, after the dead band width ΔB is increased, the adaptive current ΔI can be returned to zero. When the hunting level CH is reset, the adaptive current ΔI is set to 0. However, even if the hunting level CH is not reset, the adaptive current ΔI can be set to 0.
Furthermore, the stable set frequency (second set time, threshold value β) may be a variable value. For example, by increasing the dead band width ΔB, the hunting tendency can be set to a value considered to be improved from the hunting tendency before the adaptive current ΔI reaches the lower limit Limit. For example, the second set time and the threshold value β can be determined so that the adaptive current ΔI becomes a value smaller than the count-up speed of the hunting level before reaching the lower limit value Limit.

<Dead band width change 2>
In the first embodiment, when it is considered that the vibration state is caused by reverse input, the dead band width is gradually increased until the hunting tendency is reduced (until improved). In the case where it is considered that the vibration state is caused by the reverse input, the hunting level CH is cleared and the reverse input level CHR (= CH) is detected during the third set time, and the reverse input level CHR is detected. The dead band width after the change to a size according to the is determined. The relationship between the reverse input level CHR and the increase amount ΔBHR of the dead band width ΔB is tabulated in advance, and the increase amount ΔBHR of the dead band width ΔB is obtained using the table, and the changed dead band width ΔB (ΔB = ΔB + ΔBHR) is acquired. As shown in FIG. 16, in the second embodiment, the increase amount ΔBHR of the dead band width ΔB increases linearly as the reverse input level CHR increases.
The counting method of the reverse input level CHR is the same as the counting method of the hunting level CH.

An example of the dead band changing program in that case is shown in the flowchart of FIG.
In S121, it is determined whether or not the reverse input flag is ON. If it is ON, initial setting is performed in S122 and 123. In S122, it is determined whether or not the initial setting has been completed. If the initial setting has not been completed, the hunting level CH is set to 0 (cleared) and the hunting level CH is set to the reverse input level CHR in S123.
In S124, it is determined whether or not the third set time has elapsed since S123 was executed. Before the third set time elapses, the process returns to the execution of S121. However, since the initial setting has been completed here, S121, 122, and 124 are repeatedly executed. Until the third set time elapses, the reverse input level CHR is counted in the execution of the hunting level detection routine represented by the flowchart of FIG.
When the third set time has elapsed, the determination in S124 is YES, the reverse input level CHR is acquired in S125, the dead band width increase amount ΔBHR is acquired in S126 according to the table of FIG. Dead band width is acquired.
ΔB = ΔB + ΔBHR
Thereafter, in S128, the reverse input level CHR is cleared and the reverse input level CHR is set to the hunting level CH.

As described above, in this embodiment, the dead band width change amount ΔBHR is set to a larger value as the reverse input level CHR counted after it is determined that the vibration is caused by the reverse input, and therefore the dead band width ΔBHR. Can be changed to an appropriate value.
The third set time is a time during which the magnitude of the reverse input level CHR can be acquired, is a time used when creating the table of FIG. 16, and is a predetermined fixed value. Although the length of the third setting time is not limited, the time required for changing the dead band width can be shortened when the third setting time is shorter. The third set time can be the same length as at least one of the first set time and the second set time.
When the hunting level CH is set to 0, the adaptive current ΔI is set to 0. Therefore, the determination in S81 is NO and the reverse input flag is turned OFF.
In addition, when the dead band width ΔB is increased, the hunting tendency is improved compared to before the adaptive current ΔI reaches the lower limit value Limit, so the determination in S84 is YES and the reverse input flag is turned OFF. Thereafter, the dead zone width ΔB is not changed.
In the present embodiment, the vibration state corresponding dead band changing unit is configured by the part of the brake ECU 148 that stores the flowchart of FIG.

  In this embodiment, the hunting level CH is cleared and the reverse input level CHR is newly counted up. However, it is not essential to do so, and the hunting level CH increases within the third set time. It is also possible to acquire the amount and create a table that is a relationship between the increase amount and the increase amount of the dead band.

<Dead band width change 3>
In the third embodiment, two execution units (CPUs) 202 and 204 are provided in the brake ECU 200 as shown in FIG.
In the execution unit 202, the linear control valve control program represented by the flowchart of FIG. 6 is executed, the hunting level detection program represented by the flowchart of FIG. 8, the timer control program represented by the flowchart of FIG. The adaptive current determination program represented by the flowchart of FIG. 10 and the reverse input determination program of FIG. 13 are executed.
In the other execution unit 204, the provisional dead band width ΔBQ is set, the provisional pressure increase threshold value PQthu and the provisional pressure reduction threshold value PQthd are acquired, and the actual brake cylinder fluid pressure Pw (the detected value of the brake cylinder fluid pressure sensor 166). The number of times that the pressure has become smaller than the temporary pressure increase threshold value PQthu and the number of times that has become larger than the temporary pressure decrease threshold value PQthd are counted, and the temporary hunting level CHQ is obtained.
Even if the actual brake cylinder hydraulic pressure Pw is smaller than the temporary pressure increase threshold value PQthu or larger than the temporary pressure decrease threshold value PQthd, the pressure increase mode and the pressure decrease mode are not set. The valve 112 and the pressure-reducing linear control valve 116 are not operated. The provisional hunting level CHQ when the dead band width is assumed to be ΔBQ is acquired.
In this embodiment, the dead band width ΔBQ is acquired such that the temporary hunting level CHQ is equal to or less than the set value n, and “acquisition of the dead band after change” starts before it is determined that the input is reverse. Will be.

In the execution unit 204, the temporary dead band acquisition program represented by the flowchart in FIG. 18 is executed at predetermined time intervals.
In S151, it is determined whether or not the provisional dead band acquisition flag is ON. When S151 is first executed, the provisional dead band width ΔBQ after the change is not obtained, so that the determination is NO, and it is determined in S152 whether the fourth set time has elapsed.
The fourth set time is a time during which the temporary hunting level is detected and the temporary hunting tendency can be evaluated based on the temporary hunting level, and can be the same length as at least one of the first to third set times. Further, it may be a variable value or a fixed value.
Before the fourth set time elapses, in S153, a program similar to the hunting level detection program shown in the flowchart of FIG. 8 is executed to obtain the temporary hunting level CHR (shown in the flowchart of FIG. 9). The same applies to the timer control program to be executed). However, in this embodiment, in S33, it is determined whether or not the actual brake cylinder hydraulic pressure Pw (detected value by the brake cylinder hydraulic pressure sensor 166) has become larger than the temporary pressure reduction threshold value PQthd. The temporary decompression threshold value PQthd is expressed by the equation PQthd = Pref + ΔBQ / 2
According to the acquired size.
In S14 and S36, it is determined whether or not the actual brake cylinder hydraulic pressure Pw has become smaller than the temporary pressure increase threshold value PQthu.
According to the acquired size.

Before the fourth set time elapses, S151 to 153 are repeatedly executed, and the temporary hunting level CHQ is counted.
When the fourth set time has elapsed, the determination in S152 is YES, and in S154, the change amount ΔCHR (count-up value) of the temporary hunting level CHR within the fourth set time is acquired and is smaller than the threshold value γ. It is determined whether or not. When S154 is executed first, since the previous temporary hunting level CHR is 0, the value acquired in S153 is obtained.
The threshold value γ can be set to a small value of 1 or 2, for example, and a state in which the count-up amount of the temporary hunting level within the fourth set time is smaller than the threshold value γ is set to the temporarily stable setting state.
If the count value ΔCHR of the temporary hunting level within the fourth set time is equal to or larger than the threshold value γ, it is estimated that the hunting tendency is large even if the temporary dead band width ΔBQ is used. The dead band width ΔBQ is increased (ΔBQ ← ΔBQ + ΔBHQ). In S156, the timer for counting the fourth set time is reset and the temporary hunting level CHR is stored.
Next, when this routine is executed, the determinations in S151 and 152 are NO, so in S153, the temporary hunting level CHQ is detected based on the increased temporary dead band width (ΔBQ ← ΔBQ + ΔBHQ). .
Then, when S151 to 153 are repeatedly executed and the fourth set time has elapsed, the determination of S152 is YES, the temporary hunting level CHR is acquired in S154, and the change amount ΔCHR from the value stored in the previous S156 is reduced. It is determined whether it is smaller than the threshold value γ.
ΔCHR = CHR (n) −CHR (n−1) <γ
When the count-up amount ΔCHR during the fourth set time is equal to or greater than the threshold value γ, the temporary dead band width ΔBQ is further increased by ΔBHQ, and the temporary hunting level is counted.
While the count-up amount ΔCHR within the fourth set time is equal to or greater than the threshold value γ, S151 to 153 or S151, 152, and 154 to 156 are repeatedly executed. The temporary hunting level CHR is detected while the temporary dead band width ΔB is gradually increased by ΔBHR.
When the count-up amount ΔCHR within the fourth set time becomes smaller than the threshold value γ, the determination in S154 becomes YES, and in S157 and 158, the temporary dead band width ΔBQ is acquired and stored, and the temporary dead band width acquired flag is obtained. Is set.
Thereafter, since the determination in S151 is YES, S152 and subsequent steps are not executed.

On the other hand, in the execution unit 202, a dead zone width changing program represented by the flowchart of FIG. 19 is executed.
In S160, it is determined whether or not the reverse input flag is ON. If it is ON, it is determined in S161 whether or not the provisional dead band acquired flag is ON. If it is OFF, S160 and 161 are repeatedly executed and waited for being turned ON (waiting for the provisional dead band width ΔBQ that can reduce the hunting tendency). If it is ON, the determination in S161 is YES, and in S162, the temporary dead band width ΔBQ is read and set as the changed dead band width ΔB.
ΔB ← ΔBQ
In S163, the provisional dead band width acquired flag is reset.

In the execution unit 204, the determination in S151 is NO, so S152 and 153 are executed. However, since the dead band width ΔB is increased, the determination in S154 is YES, and the temporary dead band width ΔBQ is the dead band width at that time. It is considered that the size is substantially the same as ΔB (ΔBQ≈ΔB). In S158, the acquired flag is turned ON, and thereafter, S151 is repeatedly executed.
On the other hand, in the execution unit 202, it is considered that the reverse input flag is turned OFF by increasing the dead zone width ΔB, so that the determination in S160 is NO and it is considered that S161 and subsequent steps are not executed. .
As described above, in this embodiment, after the determination that the input is reverse, the changed dead band width (appropriate dead band width) is not acquired, but in parallel with the control of the hydraulic control actuator 118. To be acquired. Therefore, when it is determined that the hunting tendency is caused by reverse input, the dead zone width can be immediately changed to an appropriate size.
In the present embodiment, the provisional dead band width setting unit and the provisional dead band width gradually increasing unit are configured by the part that stores S155 of FIG. A temporary vibration state detection unit is configured.

<Decision of dead zone>
In the present embodiment, when the increase gradient of the target hydraulic pressure Pref is large, the pressure increase threshold value Pthu is increased (the difference between the target hydraulic pressure Pref and the pressure increase threshold value Pthu is reduced), and the target hydraulic pressure Pref. When the decrease gradient is small, the depressurization threshold Pthd is decreased (the difference between the target hydraulic pressure Pref and the depressurization threshold Pthd is small). When the increase gradient of the target hydraulic pressure Pref is large, the pressure increase mode is continuously set (it is difficult to switch to the holding mode), and when the decrease gradient of the target hydraulic pressure Pref is large, the pressure decrease mode is reduced. The mode is continuously set (it is difficult to switch to the holding mode).
If it is determined that the vibration is caused by reverse input, the dead zone width ΔB is increased. Therefore, even if the pressure increasing mode is set, it is easy to switch from the pressure increasing mode to the holding mode, and even if the pressure reducing mode is set, it is easy to switch from the pressure reducing mode to the holding mode.
Therefore, when the increase gradient dPref of the target hydraulic pressure Pref is large, the pressure increase threshold value Pthu is set to a value larger than the pressure increase threshold value Pthu determined by the dead zone width ΔB at that time, and when the decrease gradient dPref is large. The value is smaller than the pressure reduction threshold value determined by the dead band width ΔB at that time. In either case, in this embodiment, the dead zone width ΔB is reduced.
Further, the dead zone width ΔB is gradually decreased while the holding mode is set. If the dead zone width ΔB is too large with respect to the actual fluctuation range of the brake cylinder hydraulic pressure, it is reduced to an appropriate value.

The dead zone determination program represented by the flowchart of FIG. 20 is executed at predetermined time intervals.
In S180, it is determined whether or not the dead band width ΔB stored at that time is larger than the default value. That is, the vibration state resulting from the reverse input of the dead band width ΔB is detected, and it is determined whether or not it has been changed to a value larger than the default value. If the value is the same as the default value, S181 and subsequent steps are not executed. This is because if it is the default value, there is little need to adjust the dead zone. On the other hand, if it is larger than the default value, S181 and subsequent steps are executed.
In S181, 182, and 183, whether the increase gradient dPref of the target hydraulic pressure Pref is larger than the set value ΔPsu (dPref> ΔPsu), and whether the decrease gradient (negative value) is smaller than the set value ΔPsd (negative value). (DPref <ΔPsd) and whether or not the holding mode is set is determined.
When the increase gradient dPref is larger than the set value ΔPsu, in S184, as shown in the following equation, the pressure reduction threshold value Pthd is determined by the target hydraulic pressure Pref and the dead band width ΔB at that time. The pressure increase threshold value Pthu is set to a larger value (+ ΔBx / 2).
Pthu = Pref− (ΔB−ΔBx) / 2 = Pref−ΔB / 2 + ΔBx / 2
Pthd = Pref + ΔB / 2
The dead zone is asymmetric with respect to the target hydraulic pressure Pref, that is, the dead zone width (Pref−Pthu) on the pressure increase threshold side is made narrower than the dead zone width (Pthd−Pref) on the pressure reduction threshold side. The pressure threshold value Pthu is determined such that the dead band width on the pressure increase threshold value side becomes smaller than ΔB / 2. Accordingly, it is possible to prevent the holding mode from being easily set by increasing the dead band width ΔB during the pressure increase control.
The setting gradient ΔPsu may be the same as or different from the dPs used in S28 of the hunting level detection program.
On the other hand, when the decreasing gradient dPref is smaller than the set value ΔPsd, the depressurization threshold value Pthd is decreased in S185.
Pthu = Pref−ΔB / 2
Pthd = Pref + (ΔB−ΔBx) / 2
The depressurization threshold value Pthd is determined to be a value at which the dead band width on the depressurization threshold side becomes smaller than ΔB / 2. At the time of pressure reduction control, it is possible to prevent the holding mode from being easily set by increasing the dead zone width ΔB.

As shown in FIG. 22, for example, when the pressure increase gradient dPref is larger than the set gradient ΔPsu at the beginning of the brake operation, the pressure increase threshold value Pthu is increased. Therefore, it becomes difficult to switch to the holding mode, and it is possible to quickly approach the target hydraulic pressure.
In addition, when the depressurization gradient dPref is smaller than the set gradient ΔPsd when the brake operation is released, the depressurization threshold value is decreased, so that it is difficult to switch to the holding mode and the target hydraulic pressure can be quickly approached.

If the holding mode is set, the dead zone width is gradually reduced in S186. The execution of S186 is represented by the flowchart of FIG.
In S188 and 189 in the flowchart of FIG. 21, it is determined whether or not the determined flag and the searching flag are ON. First, when S188 and 189 are executed, since both flags are OFF, in S190, the dead band width ΔB determined at that time is set as the temporary dead band width ΔBQ and is reduced by ΔBH.
ΔBQ ← ΔB
ΔBQ ← ΔBQ−ΔBH
In S191, the pressure increase threshold value Pthu and the pressure decrease threshold value Pthd are obtained based on the target hydraulic pressure Pref and the temporary dead band width ΔBQ.
Pthu = Pref−ΔBQ / 2 = Pref− (ΔB−ΔBH) / 2
Pthd = Pref + ΔBQ / 2 = Pref + (ΔB−ΔBH) / 2
In S192, it is determined whether or not the actual brake cylinder hydraulic pressure Pw is smaller than the pressure increase threshold value Pthu or larger than the pressure decrease threshold value Pthd. Since the provisional dead band width ΔBQ set here is virtual, even if the actual brake cylinder hydraulic pressure exceeds the pressure increase threshold value Pthu and the pressure decrease threshold value Pthd, the pressure increase mode and the pressure decrease mode are set. There is no.
If the dead zone width ΔB is larger than the actual change in the hydraulic pressure Pw of the brake cylinder, the determination is considered to be NO. Then, in S193, it is determined whether or not the fifth set time has elapsed. If it is before the fifth set time has elapsed, a searching flag is set in S194.
Thereafter, S188, 189, 191 to 194 are repeatedly executed, and during the fifth set time, whether or not the actual brake cylinder hydraulic pressure Pw becomes smaller than the pressure increase threshold value Pthu, or becomes larger than the pressure reduction threshold value Pthd. It is determined whether or not.
The fifth set time can be a time longer than the time required for the wheel to make one rotation, and can be the same length as one of the first to fourth set times. Further, the fifth set time may be a fixed value or a variable value.
If the actual brake cylinder hydraulic pressure Pw does not exceed the pressure increase threshold value Pthu and the pressure reduction threshold value Pthd before the fifth set time has elapsed, the temporary dead zone width reduced in S190 in S195. ΔBQ is set as the dead band width ΔB (actually, the dead band width is changed), and the dead band width ΔB used in the control is reduced. Further, the provisional dead band width ΔBQ is further reduced by ΔBH.
Then, the pressure increase threshold value Pthu and the pressure reduction threshold value Pthd are obtained based on the further reduced dead zone width ΔBQ, and whether or not the actual brake cylinder hydraulic pressure Pw becomes smaller than the pressure increase threshold value Pthu. It is detected whether or not the threshold value Pthd has been exceeded.

If the actual brake cylinder hydraulic pressure Pw does not exceed the pressure increase threshold value Pthu and the pressure reduction threshold value Pthd before the fifth set time has elapsed, the determination in S193 is YES, and in S195, The temporary dead band width ΔBQ at the time is set as the dead band width ΔB, and the temporary dead band width ΔBQ is decreased.
Hereinafter, S188, 189, 191 to 194 or S188, 189, 191 to 193, and 195 are repeatedly executed until the actual brake cylinder hydraulic pressure exceeds the pressure increase threshold value Pthu and the pressure reduction threshold value thd. The dead band width ΔB is gradually decreased and the temporary dead band width ΔBQ is gradually decreased.
If the actual brake cylinder hydraulic pressure Pw exceeds the pressure increase threshold value Pthu and the pressure decrease threshold value Pthd while the fifth set time has elapsed, the determination in S192 is YES, and the determination is made in S196 and 197. The completed flag is set and the searching flag is reset.
Henceforth, since determination of S188 becomes YES, S189 and subsequent steps are not executed.
The changed dead band width ΔB is the dead band width ΔB (current value) acquired in the immediately preceding execution of S195, and the current value of the dead band width acquired in S195 is stored. The changed dead band width is not determined to be the current temporary dead band width ΔBQ, but is determined to be the current dead band width ΔB. This is because if the current provisional dead band width ΔBQ is adopted, it cannot be maintained. That is, the dead zone width ΔB is gradually decreased and changed to the value within a range in which the holding control is maintained.
As shown in FIG. 22, the dead zone width ΔB is gradually decreased (−ΔBH) while the holding mode is set, and the dead zone width is reduced by the actual brake cylinder hydraulic pressure Pw by the pressure increase threshold value Pthu. The size does not exceed the threshold value Pthd (the previous size when exceeded). The dead zone width can be reduced to an appropriate size, and it is possible to favorably avoid delays in pressure increase and pressure reduction.

  In the present embodiment, a part that stores S181 and 182 of the dead band width determination program that appears in the flowchart of FIG. 20 of the brake ECU 148, a part that executes the pressure-increasing side dead band width determination unit, and a part that stores S182 and 185, The decompression-side dead band width determination unit is configured by the portion to be executed.

In this embodiment, when the increase gradient dPref of the target hydraulic pressure Pref is larger than the set gradient ΔPsu, and when the decrease gradient dPref is smaller than the set gradient ΔPsd, the dead band width ΔB is reduced, but the dead band width ΔB is It is not essential to make it smaller. For example, when the increase gradient dPref is greater than the set gradient ΔPsu, the pressure-reduction dead zone width can be increased by the amount that the pressure-reduction dead zone width is reduced.
The dead zone is adjusted both when the increase gradient dPref of the target hydraulic pressure Pref is larger than the set gradient ΔPsu and when the decrease gradient dPref is smaller than the set gradient ΔPsd. It is also possible to adjust only in the case of.

<Prohibition / permission of changing dead band width>
In this embodiment, when there is a request to quickly change the brake cylinder hydraulic pressure, the change of the dead zone width ΔB is prohibited, and when smooth braking feeling is desired, when reduction of operating noise is desired. Allowed.
For example, when the increase gradient of the target hydraulic pressure determined based on the driver's intention is large, and when the operation speed of the brake pedal 50 is large, it is desirable to satisfy the braking request promptly, so that the operation speed is prohibited. When the vehicle travel speed is less than or equal to the set speed, it is desirable to suppress the vibration of the hydraulic pressure control actuator 118 and the like. An example of that case is shown in the flowcharts of FIGS.
The prohibition flag ON / OFF program shown in the flowchart of FIG. 23A is executed at predetermined time intervals.
In S201, whether or not the stroke changing speed (the changing speed of the detection value of the stroke sensor 160) is smaller than the set speed ΔSth, whether or not the increasing gradient dPref of the target hydraulic pressure Pref is smaller than the set gradient ΔPsa, and the traveling speed of the vehicle It is determined whether v is smaller than the set speed vth. If all three conditions are satisfied, the prohibition flag is turned OFF in S202. If all three conditions are not satisfied, the prohibition flag is turned ON in S202.
The target hydraulic pressure setting gradient ΔPsa can be set to a value smaller than the setting gradient ΔPsu used in the fourth embodiment and the setting gradient dPs used in S28 of the flowchart of FIG.
Further, the set speed ΔSth of the stroke can be a value that is considered to be a gentle operation by the driver, and the set speed vth of the vehicle speed is a speed at which the operation sound is worried (almost upper limit value). be able to.

The dead zone changing program represented by the flowchart of FIG. 23 (b) is executed at predetermined time intervals.
In S211, it is determined whether the reverse input flag is ON. If it is ON, it is determined in S212 whether the prohibition flag is ON.
If the prohibition flag is OFF, the dead zone width is changed in S213, and if it is ON, S213 is not executed. In S213, the dead zone width is changed in the same manner as in any of the first to fourth embodiments.
In this embodiment, the brake ECU 148 stores the prohibition flag ON / OFF program represented by the flowchart of FIG. 23 (a) and the dead band changing program S211 and 212 represented by the flowchart of FIG. 23 (b). The change prohibition unit is configured by the part to be executed.

Note that the hunting level CH is set to 0 when the increase gradient dPref of the target hydraulic pressure Pref is large (S29 is executed when the determination of S28 is YES). In some cases, it may be considered to be implemented.
Moreover, although the case where the prohibition flag is turned off has been described when all three conditions are satisfied, the flag may be turned off when one or more of the three conditions are satisfied. it can.
In addition to the above three conditions, the deviation between the target hydraulic pressure Pref and the actual brake cylinder hydraulic pressure Pw is smaller than the set value, the master cylinder hydraulic pressure Pmc is smaller than the set value, and the stroke is smaller than the set value. The prohibition flag can be turned off when one or more of the above conditions are satisfied.
In addition, the prohibition flag can be turned ON when antilock control, traction control, or vehicle stability control is performed.
Furthermore, when the prohibition flag is ON, the change of the first rule (decrease of the adaptive current ΔI) can be prohibited. That is, it becomes possible to prohibit the change of at least one of the first rule and the second rule.

<Change of holding valve control rules>
In the present embodiment, the content of the second rule is not the dead band width but the control rule of the holding valve 103. During normal braking (braking performed when the driver operates the brake pedal 50 and slip control such as antilock control is not performed), vibration due to reverse input is detected. If not, the holding valves 103FL, FR, RL, RR are all opened, but if vibration due to reverse input is detected, the left and right rear wheel holding valves 103RL, RR are closed. State.
In the disc brake 32 and the drum brake 36, the drum brake 36 is more likely to cause pulsation of the brake cylinder hydraulic pressure. It is also known that the fluctuation range of the brake cylinder hydraulic pressure is large.
Since the brake cylinder hydraulic pressure sensor 166 is provided in the common passage 102, if the brake cylinder 46 of the drum brake 36 is cut off from the common passage 102, vibration of the detection value of the brake cylinder hydraulic pressure sensor 166 is suppressed. The

In the present embodiment, the holding valve control program represented by the flowchart of FIG. 24 is executed at predetermined time intervals. In S221, it is determined whether or not there is a normal braking request for the hydraulic brake 26. If there is a normal braking request, it is determined in S222 whether the reverse input flag is ON. If the reverse input flag is OFF, the holding valves 103RL and RR for the left and right rear wheels are opened in S223. If the reverse input flag is ON, in S224, the left and right rear wheel holding valves 103RL, RR are closed.
Thus, when the reverse input flag is ON and there is a normal braking request for the hydraulic brake 26, the holding valves 103RL and RR are closed. Therefore, it is possible to favorably avoid the occurrence of control hunting.
In the present embodiment, the electromagnetic valve control rule changing unit is configured by the part for storing the rear wheel holding valve control program represented by the flowchart of FIG. The brake cylinder shut-off unit is configured by the part, the part to be executed, and the like.
In the flowchart of FIG. 24, when there is no normal braking request for the hydraulic brake 26, the holding valves 103RL and RR are controlled in accordance with the execution of another program.

  In the above embodiment, hunting due to reverse input is estimated to be caused by the drum brake 26 of the rear wheels 16 and 18, and the holding valves 103RL and RR of the rear wheels 16 and 18 are closed. However, the holding valves 103FL, FR, RL, and RR are closed in order, and the hunting state is detected each time, and the hydraulic brakes 22 and 26 that cause reverse input can be specified.

<Hydraulic brake circuit>
Further, the hydraulic brake circuit is not limited to that shown in FIG. Any circuit including a hydraulic control mechanism corresponding to the pressure-increasing linear control valve 112 or the pressure-decreasing linear control valve 116 can be implemented in the same manner.
<Hydraulic brake circuit 1>
For example, a hydraulic brake circuit can be shown in FIG. In this hydraulic brake circuit, the pressure-reducing linear control valve 116 is not provided. When reducing the hydraulic pressure of the common hydraulic pressure 102, one or more of the pressure reducing valves 106FL, FR, RL, RR are opened. In the open state of the holding valves 103FL, FR, RL, RR, the hydraulic pressure in the common passage 102 can be controlled to be reduced by controlling the pressure reducing valve 106. The present invention can be applied to control of the pressure-increasing linear control valve 112 of the hydraulic brake circuit of FIG.

<Hydraulic brake circuit 2>
The hydraulic brake circuit may be as shown in FIG. In this hydraulic brake circuit, the point that the brake cylinders 32 and 36 are connected to the common passage 102 is the same, but the master cylinder is a master cylinder 260 with a hydro booster. The master cylinder 260 with a hydro booster includes a power piston 262 linked to the brake pedal 50, and a pressure piston 263 linked to the power piston 262, and includes a booster chamber 264 and a pressure piston 263 behind the power piston 262. A booster passage 266 and a master passage 268 are connected to the front pressurizing chamber 265 and connected to the common passage 102, respectively.
The pressure-increasing linear control valve 112 and the pressure-reducing linear control valve 116 have the same structure as the pressure-increasing linear control valve 112 and the pressure-reducing linear control valve 116 shown in FIG. 3, and the present invention can be applied to these controls. it can.

<Hydraulic brake circuit 3>
The hydraulic brake circuit may be as shown in FIG.
In the present hydraulic brake circuit, a pressure-increasing linear control valve 290 is provided between the power hydraulic pressure source 54 and each brake cylinder 32FL, FR, 36RL, RR, and the brake cylinders 32FL, FR, the reservoir 94, and the like. Between them, a normally closed pressure-reducing linear control valve 292 is provided, and between the brake cylinders 36RL, RR and the reservoir 94, a normally-open pressure reducing linear control valve 294 is provided. The hydraulic pressure control actuator 296 is configured by the pressure-increasing linear control valve 290 and the pressure-decreasing linear control valves 292, 294, etc. In this embodiment, the hydraulic pressure control actuators 296FL, FR, RL, RR are respectively provided for each wheel. Will be provided.
A brake cylinder hydraulic pressure sensor 300 is provided corresponding to each brake cylinder 32FL, FR, 36RL, RR.
The differential pressure before and after each of the pressure increasing linear control valves 290 can be obtained as the difference between the detected value of the brake cylinder hydraulic pressure sensor 300 and the detected value of the accumulator pressure sensor 164.
In this embodiment, the pressure-increasing linear control valve 290 and the pressure-reducing linear control valve 292 have the same structures as those of the pressure-increasing linear control valve 112 and the pressure-reducing linear control valve 116 shown in FIG. Can be applied. Further, since the decompression linear control valve 294 is a normally open valve, the rules for determining the amount of supply current are different, but the other points are the same, and therefore the present invention can be applied.
In the present embodiment, since the hydraulic control actuators 296FL, FR, RL, RR are provided for each wheel, the present invention can be applied to each of these hydraulic control actuators 296FL, FR, RL, RR. It is possible to change the first rule and the second rule independently of each other.

<Hydraulic brake circuit 4>
A hydraulic brake circuit may be as shown in FIG. In this embodiment, left and right communication valves 332 and 334 are provided between the left and right front wheel brake cylinders 32FL and FR and between the left and right rear wheel brake cylinders 36RL and RR, respectively. The left and right communication valves 332 and 334 are normally open electromagnetic on-off valves. In the case of an abnormality in the electrical system of the hydraulic brake system, no current is supplied to the coils of all the solenoid valves, so that the state shown in FIG. When the driver operates the brake pedal 50 in this state, fluid pressure is generated in the pressurizing chambers 64a and 64b of the master cylinder 52, but the left and right communication valves 332 and 334 are in an open state. Pressure can be supplied to the four brake cylinders 32,36.

<Hydraulic brake circuit 5>
A hydraulic brake circuit may be as shown in FIG. In this embodiment, a hydraulic pressure generator 340 is provided. The hydraulic pressure generator 340 includes: (a) a manual-based hydraulic pressure generation state in which the pressurizing pistons 342 and 343 are advanced by operating the brake pedal 50 to generate hydraulic pressure in the pressurizing chambers 344 and 346; The hydraulic pressure of the power hydraulic pressure source 54 controlled by the hydraulic pressure control actuator 348 is transferred to the rear hydraulic pressure chamber 350 behind the intermediate piston 349 and the intermediate hydraulic pressure chamber 352 between the intermediate piston 349 and the pressurizing piston 343. A power hydraulic pressure generation state in which a hydraulic pressure is generated by being supplied; and (c) a stroke simulator state in which the spring 356 is expanded and contracted by the advance of the input piston 354 accompanying the operation of the brake pedal 50 and a reaction force is applied. Can be taken.
When the hydraulic brake system is normal, the control valve 358 is closed. The movement of the intermediate piston 349 is blocked, and the stroke simulator state is set. When hydraulic pressure is supplied to the rear hydraulic pressure chamber 350 and the intermediate hydraulic pressure chamber 352, the pressurizing pistons 342 and 343 are advanced in the stroke simulator state, and the pressurizing chambers 344 and 346 include the intermediate hydraulic pressure chamber 352. The hydraulic pressure corresponding to the hydraulic pressure is generated, and the power hydraulic pressure is generated.
When the electric system is abnormal, the control valve 358 is opened. By operating the brake pedal 50, the input piston 354 is advanced, and the intermediate piston 349 is advanced. Since the movement of the intermediate piston 349 prevents the expansion and contraction of the spring 356, the input piston 354 and the intermediate piston 349 are moved together. When the intermediate piston 349 comes into contact with the pressure piston 342, the pressure pistons 342 and 344 are advanced. The pressurizing chambers 344 and 346 are brought into a manual-based hydraulic pressure generation state in which a hydraulic pressure having a magnitude corresponding to the operating force is generated.
The hydraulic pressure in the pressurizing chambers 344 and 346 is supplied to the brake cylinders 32 and 36 through the master passages 360 and 362.

The hydraulic control actuator 348 includes a pressure-increasing linear control valve 382 and a pressure-decreasing linear control valve 384, and controls the hydraulic pressure in the rear hydraulic pressure chamber 350 and the hydraulic pressure in the intermediate hydraulic pressure chamber 352 in the power hydraulic pressure generation state. Thus, the hydraulic pressure in the pressurizing chambers 344 and 346 is controlled, and the hydraulic pressure in the brake cylinders 32 and 36 is controlled.
The pressure-increasing linear control valve 382 and the pressure-decreasing linear control valve 384 have the same structure as the pressure-increasing linear control valve 112 and the pressure-decreasing linear control valve 116 in FIG. 3, and the present invention can be applied to these controls. it can.

As described above, a plurality of examples have been described, but the present invention can be implemented in a mode in which two or more of the examples are appropriately combined.
Further, the present invention can be applied to various hydraulic brake circuits.
Further, in each of the above embodiments, the hydraulic pressure of the power hydraulic pressure source is controlled by the control of the electromagnetic control valve. However, it can be controlled by the control of the pump motor ( Drive source control hydraulic pressure control device). In that case, the present invention can be applied in the control of the current supplied to the electric motor.
Further, the brake may be an electric brake, and in this case, the present invention can be applied in the control of the drive electric motor.
In addition to the above-described embodiments, the present invention can be carried out in various modifications and improvements based on the knowledge of those skilled in the art.

  22: Disc brake 26: Drum brake 32, 36: Brake cylinder 50: Brake pedal 54: Powered hydraulic pressure source 102: Common passage 103: Holding valve 112: Boosting linear control valve 116: Decreasing linear control valve 118: Hydraulic pressure Control actuator 148: Brake ECU 164: Accumulator pressure sensor 166: Brake cylinder hydraulic pressure sensor 180: Feed forward control unit 182: Feedback control unit 200: Brake ECU 202, 204: Execution unit 290: Boosting linear control valve 292: Normally closed Pressure reducing linear control valve 294: normally open pressure reducing linear control valve 348: pressure increasing linear control valve 384: pressure reducing linear control valve

Claims (11)

A brake force control device including a brake force control mechanism capable of controlling a brake force of a brake that suppresses rotation of a vehicle wheel, and controlling the brake force control mechanism according to a plurality of rules, thereby bringing the brake force close to a target value Because
A vibration state detection device for detecting a state of vibration of the brake force;
A first rule changing unit that changes the content of a first rule that is at least one of the plurality of rules based on a vibration state detected by the vibration state detection device;
Even if the first rule is changed by the first rule changing unit, if the vibration state detected by the vibration state detection device does not improve, at least one of the rules excluding the first rule from the plurality of rules. And a second rule changing unit that changes the content of the second rule, which is one rule. The brake force control device controls the current supplied to the brake force control mechanism according to at least the first rule and the second rule, so that the brake force is a dead band determined by the target value and the dead band width. A current-control-use braking force control unit that holds the braking force when inside, and increases or decreases the braking force when the braking force is outside the dead zone;
Current that changes the content of the rule that determines the amount of current supplied to the brake force control mechanism when the first rule change unit increases or decreases the brake force as the first rule The amount determination rule changing unit is included, and the second rule changing unit includes a dead band width changing unit that changes the dead band width representing the content of the rule for determining the dead band as the second rule. Brake force control device.   The vibration state detection device includes a dead band use vibration state detection unit that detects the vibration state based on a frequency at which the braking force changes from the inside to the outside of the dead band, and the second rule changing unit includes the second rule changing unit, The frequency of the vibration state detected by the dead-zone use vibration state detection unit after the content of the first rule is changed to the setting content by the first rule changing unit before the vibration state is changed to the setting content. The brake force control device according to claim 2, further comprising an unimproved change unit that changes the dead zone width when the frequency of the vibration state detected by the detection device does not become lower than the frequency.   The dead band width changing unit includes a dead band width gradually increasing unit that gradually increases the dead band width until the frequency of the vibration state detected by the dead band using vibration state detecting unit reaches a stable setting frequency, and the dead band width gradually increasing unit. The brake force control device according to claim 3, wherein the dead band width gradually increased by step S is used as the dead band width after change.   The dead band width changing unit includes a temporary dead band width setting unit that temporarily sets the dead band width, and the dead band using vibration state detecting unit includes the temporary dead band width and the braking force set by the temporary dead band width setting unit. A provisional dead band use vibration state estimation unit that estimates the vibration state based on the provisional dead band width setting unit, wherein the provisional dead band use vibration state detection unit estimates the frequency of the provisional vibration state as a provisional stable side set frequency. The brake force control device according to claim 3, further comprising a provisional dead band width gradually increasing portion that gradually increases the provisional dead band width.   The temporary dead band use vibration state detection unit is set by the brake force and the temporary dead band width setting unit when a current supplied to the brake force control mechanism is controlled by the current control use brake force control unit. The brake force control device according to claim 5, further comprising a temporary vibration state detection unit that temporarily detects the vibration state based on the provisional dead band width.   The dead zone width changing unit includes a vibration state corresponding dead band width changing unit that changes the dead band width to a size according to a vibration state detected by the vibration state detection device. The brake force control device described in 1.   The brake force control device includes a dead zone determining unit that determines the dead zone based on the target value and the dead zone width changed by the dead zone width changing unit, and the dead zone determining unit includes (i) the target value When the increase gradient is larger than the set increase gradient, the increase-side dead band width that is the absolute value of the difference between the target value and the switching threshold value for switching from increase control to hold control is changed from the target value and decrease control to hold control. An increase request dead band determining unit that determines to be smaller than a decrease side dead band width that is an absolute value of a difference between the switching threshold value to be switched, and (ii) when the decrease gradient of the target value is larger than a set decrease gradient, The braking force according to any one of claims 2 to 7, including at least one of a reduction request dead zone width determination unit that determines the reduction side dead zone width to be smaller than the increase side dead zone width. Control device.   The brake force control device changes at least one of the first rule and the second rule corresponding to at least one of the first rule changing unit and the second rule changing unit. 2. A change prohibiting unit that prohibits when the increase gradient of the target value is larger than a set gradient and at least one of a case where a deviation obtained by subtracting an actual braking force from the target value is larger than a set deviation. Or the braking force control device according to any one of 8 to 8; The brake is a hydraulic brake that is provided corresponding to a wheel of the vehicle and is operated by a hydraulic pressure of a brake cylinder;
The hydraulic pressure control mechanism as the brake force control mechanism includes (i) (a) a power source that is actuated by supplying current, and a power type hydraulic pressure source that is driven by the drive source; and (b) the drive A drive source control hydraulic pressure control device including a drive source current control unit that controls an output hydraulic pressure of the power hydraulic pressure source by controlling a supply current to the source; and (ii) (c) a high pressure operation A hydraulic pressure source capable of outputting liquid, (d) one or more electromagnetic hydraulic pressure control valves capable of controlling the hydraulic pressure of the hydraulic pressure source, and (e) controlling a supply current to the electromagnetic hydraulic pressure control valve. The brake force control device according to any one of claims 1 to 9, including at least one of a solenoid valve control utilization fluid pressure control device including a solenoid valve current control unit that controls an output fluid pressure by doing so. The brakes are respectively provided corresponding to a plurality of wheels of the vehicle, and each is a hydraulic brake operated by a hydraulic pressure of a brake cylinder,
The brake cylinders of these multiple hydraulic brakes are each connected to a common passage,
The common cylinder is provided with a brake cylinder hydraulic pressure detecting device for detecting the brake cylinder hydraulic pressure as the brake force,
The hydraulic control mechanism as the brake force control mechanism includes an electromagnetic control valve provided between the common passage and each of the plurality of brake cylinders,
The vibration state detection device includes a sensor value-based vibration state detection unit that detects the vibration state using a detection value by the brake cylinder hydraulic pressure detection device,
The plurality of electromagnetic controls when the second rule change unit does not improve the vibration state detected by the sensor value-based vibration state detection unit after the first rule is changed by the first rule change unit. Including a solenoid valve control rule changing unit for changing the contents of the valve control rules,
The brake force control device closes an electromagnetic control valve corresponding to at least one brake cylinder determined by a vibration state of hydraulic pressure among the plurality of brake cylinders according to the rule changed by the electromagnetic valve control rule changing unit. The brake force control device according to any one of claims 1 to 10, further comprising: a brake cylinder blocking portion that blocks the at least one brake cylinder from the common passage.

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