JP2008273346A - Brake control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brake control device for a vehicle capable of ensuring the direction stability of the vehicle by restricting an increase in the braking liquid pressure of a turning inner side wheel while maintaining an increase characteristic of a vehicle deceleration degree relative to a braking operation amount to an approximately constant degree in a vehicle turning state in the brake control device for the vehicle provided with liquid pressure pipes of two systems. <P>SOLUTION: In the device, braking pressure (wheel cylinder pressure) is generated by adding auxiliary pressure adjusted by a hydraulic pump and a solenoid valve to master cylinder pressure from a time when a braking operation amount reaches a minute value (including "0"). An auxiliary pressure reference value is determined based on the braking operation amount. One or both of turning inner side wheels in which a ground-contact load is reduced are selected based on the turning state of the vehicle and the wheel state in the vehicle turning state, and an increase in the braking pressure is restricted as for the selected wheel. On the other hand, the auxiliary pressure to one or two liquid pressure pipes including the wheel other than the selected one is increasingly corrected to the auxiliary pressure reference value. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle brake control device.

Patent Document 1 includes a first hydraulic pipe including first and second wheel cylinders, and a second hydraulic pipe including third and fourth wheel cylinders, depending on the vehicle running state. A vehicle brake device is described in which the brake hydraulic pressure distribution of the two hydraulic pipes is adjusted to adjust the brake hydraulic pressure distribution of the wheels.
Japanese Patent Laid-Open No. 9-290731

  More specifically, in this apparatus, a hydraulic pump that generates an auxiliary hydraulic pressure added to the master cylinder pressure is provided in one of the two hydraulic pipings. At the time of a braking operation in a straight vehicle state, the master cylinder pressure itself is supplied to the two hydraulic pipes. On the other hand, at the time of a braking operation in a state where the steering operation angle is large (vehicle turning state), the hydraulic pump is operated and a braking hydraulic pressure larger than the master cylinder pressure is supplied to the one hydraulic piping. Thus, it is described that a larger braking force can be obtained during a braking operation in a vehicle turning state than in a braking operation in a vehicle straight traveling state.

  However, this means that the vehicle deceleration increase characteristic (the relationship between the braking operation amount and the vehicle deceleration) differs between the vehicle turning state and the vehicle straight traveling state. In general, it is considered preferable that the increase characteristic of the vehicle deceleration with respect to the braking operation amount is kept constant even if the brake hydraulic pressure distribution of the wheels is changed.

  In addition, at the time of a braking operation in a vehicle turning state, the ground contact load of the turning inner wheel decreases due to the load movement to the outside of the turning. As a result, since it is difficult to ensure the cornering force of the turning inner wheel, a state in which it is difficult to ensure the directional stability of the vehicle is likely to occur. In this case, in order to ensure the directional stability of the vehicle, the cornering force (lateral force) of the turning inner wheel is limited by limiting the increase of the brake fluid pressure of the turning inner wheel (and hence the increase of the braking force (front / rear force)). It is considered preferable to suppress a decrease in the limit value.

  The present invention has been made on the basis of such knowledge, and an object of the present invention is to maintain a vehicle deceleration increasing characteristic with respect to a braking operation amount substantially constant in a vehicle braking control device including two hydraulic pipings. On the other hand, an object of the present invention is to provide a vehicle that can ensure the directional stability of a vehicle by restricting an increase in the brake fluid pressure of a specific wheel.

  The vehicle braking control device according to the present invention includes four wheel braking devices that respectively apply braking torque corresponding to the braking hydraulic pressure supplied to the wheel cylinders of the four front, rear, left, and right wheels of the vehicle to the corresponding wheels, A first hydraulic pressure generating device (master cylinder) having two hydraulic pressure generating chambers each generating a hydraulic pressure amount corresponding to a braking operation amount by a driver of the vehicle, and of the two hydraulic pressure generating chambers, A first hydraulic pipe that hydraulically connects one of the four wheel braking devices corresponding to the left and right front wheels or two corresponding to the left front wheel and the right rear wheel; and the two hydraulic pressures A second hydraulic piping that hydraulically connects the other of the generation chambers to two of the four wheel braking devices corresponding to the left and right rear wheels or two corresponding to the right front wheel and the left rear wheel; Is provided. In other words, the vehicle braking control device may include a so-called “front and rear pipe” or a so-called “diagonal pipe (also referred to as X pipe)”.

  The vehicle brake control device according to the present invention generates an auxiliary hydraulic pressure that is added to the hydraulic pressure amount generated by the first hydraulic pressure generating device in each of the first and second hydraulic pressure pipes. A power-driven second hydraulic pressure generator (hydraulic pump), a braking operation amount detection means for detecting the braking operation amount, a state quantity acquisition means for acquiring a turning state quantity representing the turning motion of the vehicle, In the turning state of the vehicle, at least one of the turning inner front and rear wheels is selected as a selected wheel based on the acquired turning state amount, and the brake fluid supplied to the wheel braking device corresponding to the selected wheel A determination reference value of the braking operation amount used for the start determination of the pressure increase restriction control for changing the pressure below the hydraulic pressure in the corresponding hydraulic pressure pipe is determined based on the acquired turning state quantity, Detected braking operation A pressure increase limiting control means for starting and executing the pressure increase limiting control in response to the amount exceeding the determination reference value, and the first hydraulic pressure pipe based on the detected braking operation amount. A reference amount determining means for determining a first auxiliary hydraulic pressure reference amount and a second auxiliary hydraulic pressure reference amount in the second hydraulic piping; and the determined first and second auxiliary hydraulic pressure reference amounts; Based on the acquired turning state quantity, a first auxiliary hydraulic pressure target quantity in the first hydraulic pipe is determined to be equal to or greater than the first auxiliary hydraulic pressure reference quantity, and the second hydraulic pipe is used. The target amount determining means for determining the second auxiliary hydraulic pressure target amount at or above the second auxiliary hydraulic pressure reference amount and the auxiliary hydraulic pressure in each of the first and second hydraulic pipings is determined. Pressure adjusting means for adjusting the first auxiliary fluid pressure target amount and the second auxiliary hydraulic pressure target amount so as to coincide with each other It has to.

  According to this, when the braking operation amount exceeds the determination reference value during the braking operation in the vehicle turning state, the “pressure increase limiting control” is executed and the “selected wheel” (= any one of the front and rear wheels inside the turning). One or both) of the brake fluid pressure increase (thus increasing the braking force (front / rear force)) is limited. Therefore, a decrease in the limit value of the cornering force (lateral force) of the selected wheel is suppressed, and a sufficient cornering force of the selected wheel (= turning inner wheel) can be ensured. As a result, the directional stability of the vehicle is easily ensured.

  In addition, during the braking operation in the vehicle turning state, the braking hydraulic pressure of the first hydraulic pipe (master cylinder pressure + auxiliary in the first hydraulic pipe is based on the turning state amount acquired by the acquisition unit. (Hydraulic pressure) is adjusted to a value equal to or greater than the first reference hydraulic pressure (master cylinder pressure + first auxiliary hydraulic pressure reference amount), and the braking hydraulic pressure (master cylinder pressure + second hydraulic pressure) of the second hydraulic pressure pipe is adjusted. The auxiliary hydraulic pressure in the pressure pipe) is adjusted to a value equal to or higher than the second reference hydraulic pressure (master cylinder pressure + second auxiliary hydraulic pressure reference amount). That is, one or both of the brake hydraulic pressures of the first and second hydraulic pipes are increased and corrected with respect to the corresponding reference hydraulic pressure. Hereinafter, the control in which the braking hydraulic pressure of the hydraulic piping is increased and corrected from the reference hydraulic pressure in this way is also referred to as “auxiliary hydraulic pressure increase control”.

  As described above, the “auxiliary hydraulic pressure increase control” is performed on one or both of the braking hydraulic pressures of the first and second hydraulic pipings, thereby braking the wheels other than the selected wheels. Can increase. Due to the increase in the braking force of the wheels other than the selected wheel, a decrease in the braking force of the selected wheel due to the execution of the “pressure increase limiting control” for the selected wheel can be compensated. As a result, the increase characteristic of the vehicle deceleration with respect to the braking operation amount can be maintained substantially constant.

  In addition, by executing the “pressure increase limiting control” and the “auxiliary hydraulic pressure increase control”, the left / right difference in braking force (not only the left / right difference between the left and right front wheels and the left and right rear wheels, but also the left side located on the diagonal of the vehicle body) Including the left-right difference between the right wheel and the right wheel), and a turning outward yaw moment is generated. This also improves the directional stability of the vehicle.

  As described above, according to the vehicle braking control apparatus of the present invention, in the case of front and rear piping or diagonal piping, the vehicle deceleration increasing characteristic with respect to the braking operation amount is maintained substantially constant in the vehicle turning state. On the other hand, it is possible to restrict the increase in the brake fluid pressure of the turning inner wheel and ensure the directional stability of the vehicle.

  In the vehicle brake control device according to the present invention, the brake operation amount determination reference value is used as the determination reference value used for the start determination of the “pressure increase restriction control”. The determination reference value or the determination reference value of the brake fluid pressure corresponding to the selected wheel may be used. In this case, when the vehicle body deceleration exceeds the determination reference value, or when the brake fluid pressure corresponding to the selected wheel exceeds the determination reference value, “pressure increase limiting control” is started and executed. This is based on the fact that the vehicle body deceleration or the brake fluid pressure is a value corresponding to the amount of braking operation.

  Furthermore, the determination reference value of the turning state amount may be used as a determination reference value used for the start determination of “pressure increase restriction control”. In this case, when the turning state quantity exceeds the determination reference value, the “pressure increase limiting control” is started / executed.

  As described above, the case where the “pressure increase restriction control” and the “auxiliary fluid pressure increase control” are executed in the vehicle turning state has been described. However, the “pressure increase restriction control” does not depend on whether the vehicle is turning. And “auxiliary hydraulic pressure increase control” can be executed. In this case, at least one of the left and right rear wheels (based on the wheel state quantity) is selected as the selected wheel, and the slipperiness of the wheel is used as a determination reference value used for determining the start of the “pressure increase limiting control”. The wheel state quantity determination reference value representing That is, when the wheel state quantity exceeds the determination reference value, “pressure increase limiting control” is started and executed.

  In the vehicle brake control device according to the present invention, the determination reference value may be determined based on a vehicle body speed of the vehicle. In this case, the determination reference value may be set to a smaller value as the vehicle body speed increases. According to this, the higher the vehicle body speed, that is, the greater the degree to which the directional stability of the vehicle is required, the earlier the “pressure increase limiting control” can be started.

  In the vehicular braking control apparatus according to the present invention, when the braking state quantity at the start of braking acquired as the turning state quantity at the start of the braking operation by the driver is less than or equal to a predetermined value, the pressure increase restriction The control means is configured not to perform the pressure increase restriction control, and the target amount determination means uses the first and second auxiliary hydraulic pressure target amounts as the first and second auxiliary hydraulic pressure reference amounts. Preferably, each is configured to maintain an equal value. That is, when the amount of turning state is small at the start of the braking operation (in the case of a substantially straight traveling state), execution of “pressure increase limiting control” and “auxiliary hydraulic pressure increase control” is prohibited.

  The oversteer tendency of the vehicle (involved inside the turning) becomes prominent when the braking operation is started in a state where the turning state amount is large. In this case, the “pressure increase limiting control” and the “auxiliary hydraulic pressure increase control” are very effective. On the other hand, when the turning is started after the braking operation is started in the substantially straight traveling state, the oversteer tendency of the vehicle (involvement inside the turning) hardly occurs. In this case, the necessity of performing the “pressure increase limiting control” and the “auxiliary hydraulic pressure increase control” is low.

  The above configuration is based on such knowledge. According to this, when the turning is started after the braking operation is started in the substantially straight traveling state, the “pressure increase limiting control” and the “auxiliary hydraulic pressure increase control” are prohibited. Thereby, it is possible to suppress unnecessary execution of the “pressure increase limiting control” and the “auxiliary hydraulic pressure increase control”.

  Embodiments of a vehicle brake control device according to the present invention will be described below with reference to the drawings.

<Overall configuration of the device>
First, the overall configuration of the vehicle brake control device according to the embodiment will be described with reference to FIGS. 1 and 2. In FIGS. 1 and 2, the case where the brake piping is “front and rear piping” is mainly shown, and the case of “diagonal piping (also referred to as X piping)” is shown in parentheses. The same applies to other figures.

  The first pressure generating means (corresponding to the “first hydraulic pressure generating device”) is the master cylinder MC. The master cylinder MC has two hydraulic pressure generation chambers (not shown), and generates a braking pressure (hydraulic pressure) in response to the driver's operation (braking operation) of the brake pedal BP. That is, the braking pressure is generated using the power generated by the driver as a power source. Furthermore, in order to reduce the brake pedal operating force, the master cylinder MC can be provided with a vacuum booster VB (also referred to as a negative pressure booster or a brake booster).

  The second pressure generating means (corresponding to the “second hydraulic pressure generating device”) is a fluid pump HP # (also referred to as a hydraulic pump, hereinafter simply referred to as a pump) driven by an electric motor M, and is operated. The braking pressure is generated by a power source (for example, a power source) that is separate from the person's power. The pump HP # sucks a part of the fluid discharged from the master cylinder MC and discharges it to the wheel cylinder WC **.

  Here, “#” is a subscript indicating each system in the two systems of braking piping (hydraulic piping). When the brake pipe is a front and rear pipe, “f” represents the front wheel system, “r” represents the rear wheel system, and when the brake pipe is a diagonal pipe, “1” represents the first system and “2” represents the second system. Represents. The subscript “#” is the same in the following. “**” is a subscript meaning each wheel, “fl” represents the left front wheel, “fr” represents the right front wheel, “rl” represents the left rear wheel, and “rr” represents the right rear wheel. The subscript “**” is the same in the following.

  In this way, the pump HP # sucks the fluid from the pipe part LM # and discharges it to the pipe part LW **. For this reason, the movement of the fluid occurs, and an auxiliary braking pressure is generated with respect to the braking pressure generated by the master cylinder MC.

  The detection means BS detects the braking operation amount Bs by the driver's braking operation member (for example, the brake pedal BP). Specifically, the braking pressure (master cylinder pressure Pm #) in the master cylinder MC or two braking pipes (first and second hydraulic pipes) connected to the two hydraulic pressure generation chambers of the master cylinder MC, respectively. Is detected. Therefore, the master cylinder pressure Pm # can be used as the braking operation amount Bs. Further, the displacement (stroke) and operating force of the brake pedal BP can be detected, and these detected values (brake pedal stroke or brake pedal operating force) can be used as the braking operation amount Bs.

  The pressure adjusting means (corresponding to the “pressure adjusting means”) is, for example, a linear pressure adjusting valve LV # (also referred to as a linear solenoid valve or a linear control valve), and is generated by a second pressure generating means (pump / electric motor). The pressure is adjusted based on an auxiliary pressure target value SP # t described later. Then, the braking pressure generated by the second pressure generating means (pump / electric motor) is added to the braking pressure generated by the first pressure generating means (master cylinder MC) and applied to the wheel cylinder WC **. The number of rotations of the electric motor M is controlled to generate a necessary pressure, and the final pressure adjustment is performed by the linear solenoid valve LV #.

  The pressure increase limiting means, which is a means for limiting the increase in braking pressure, is a brake pressure Pw ** in the wheel cylinder so that the braking pressure Pw ** in the wheel cylinder changes below the braking pressure Ph # in the pump discharge side pipe. Adjust (limit). For example, an inlet valve IV ** (also referred to as a pressure increasing solenoid valve) and an outlet valve OV ** (also referred to as a pressure reducing solenoid valve) used for ABS control can be used.

《Brake control configuration》
Next, the configuration of the braking control by the vehicle braking control apparatus according to the embodiment will be described with reference to FIG.

<Calculation of auxiliary pressure reference value SP # o>
The reference value of the pressure (pressure added to the braking pressure) for assisting (assisting) the braking pressure generated by the first pressure generating means (master cylinder MC) is the operation amount of the braking member (brake pedal BP) of the driver. (Hereinafter referred to as braking operation amount Bs). The braking operation amount Bs is calculated based on the detection result of the braking operation amount detection means BS (using at least one of the brake pedal stroke sensor, the brake pedal operation force sensor, and the master cylinder pressure sensor PM #). The The braking pressure generated by the master cylinder MC is the same as the pressure in the piping part LM #.

  The purpose of the driver's braking operation is to decelerate the vehicle (vehicle body). The braking device presses the brake pad against the brake rotor by the braking pressure, and generates a braking force on the wheel by the frictional force at that time. For this reason, the target of braking control is pressure (pressure of fluid in the wheel cylinder). Therefore, it is desirable to use the master cylinder pressure Pm # that is the same physical quantity as the braking operation amount Bs.

  Since the method for determining the reference value of the auxiliary pressure (corresponding to the “auxiliary hydraulic pressure reference amount”, hereinafter simply referred to as the reference value SP # o) is slightly different depending on the type of the brake pipe, first the case of the front and rear pipes will be described. To do.

  Based on the vehicle reference specifications, the braking force distribution between the front and rear wheels (front / rear braking force distribution) is calculated based on the braking operation amount Bs of the driver. The standard specifications of the vehicle are values such as the vehicle weight Ms, the position of the center of gravity, the wheel base L, and the like, and are values that change depending on the occupant and the loading state, but assume a predetermined state (a predetermined number of passengers and loading amount). It is the value.

  The auxiliary pressure reference value SP # o (SPfo, SPro) is a so-called ideal braking force distribution (a distribution in which the braking force of the front and rear wheels becomes a braking force proportional to each load in consideration of load movement during braking), or It is calculated from the braking force distribution characteristic approximated to it.

  FIG. 4 is a table of auxiliary pressure reference values SPfo and SPro for the front and rear wheels with respect to the braking operation amount Bs. In this case, the auxiliary pressure reference value SP # o increases proportionally (linearly) from “0” as the braking operation amount Bs increases from “0”. The auxiliary pressure reference values SPfo and SPro for the front wheels and the rear wheels may be the same value or different.

  Further, as shown in FIG. 5, the auxiliary pressure reference value SPfo for the front wheels is set to increase from “0” with the characteristic of “convex downward” in accordance with the increase in the braking operation amount Bs from “0”. Get (see solid line). Alternatively, as indicated by a dashed line approximating the characteristic of “convex downward”, it is also set to increase from “0” by a plurality of straight lines whose inclination increases as the braking operation amount Bs increases from “0”. Can be done.

  On the other hand, the auxiliary pressure reference value SPro for the rear wheels can be set to increase from “0” with a “convex upward” characteristic in response to an increase in the braking operation amount Bs from “0” (see the solid line). . Alternatively, as indicated by a broken line approximating the characteristic of “convex upward”, it is also set to increase from “0” by a plurality of straight lines whose inclination decreases as the braking operation amount Bs increases from “0”. Can be done. Thus, the braking force distribution between the front and rear wheels can be made closer to the ideal braking force distribution.

  The auxiliary pressure can be set based on an estimated ground load of each wheel. In this case, the target value of the vehicle body deceleration is determined based on the braking operation amount Bs, and the total braking force for realizing this is calculated. The total braking force is distributed based on the ground contact load of each wheel. The ground load can be estimated based on the detection result of the longitudinal acceleration sensor GX, the vehicle body deceleration Gx obtained by differentiating the vehicle body speed Vx, and the vehicle reference specifications. Even in this case, the auxiliary pressure reference value SP # o is calculated based on the braking operation amount Bs.

  On the other hand, when the braking pipe is a diagonal pipe, unlike the front and rear pipes, the auxiliary pressure reference values SP1o and SP2o are calculated with the same characteristics in the first and second systems, as shown in FIG. In this case, as indicated by the solid line, the auxiliary pressure reference value SP # o is set so as to increase proportionally (linearly) from “0” in accordance with the increase in the braking operation amount Bs from “0”. Alternatively, as indicated by a broken line, it may be set to increase from “0” with a “convex downward” characteristic in accordance with an increase in the braking operation amount Bs from “0”.

  In setting the auxiliary pressure, an arbitrary amount of braking operation can be set as the starting point (starting point) for applying the auxiliary pressure. Here, it is desirable that a minute braking operation amount including “0” (“0” or a minute value in the vicinity of “0”) is used as a starting point for applying the auxiliary pressure. Although the operation characteristic of the brake pedal BP is changed by the application of the auxiliary pressure, a sense of discomfort to the driver can be suppressed by using a small amount of braking operation including “0” as the starting point of the application of the auxiliary pressure.

  Furthermore, when a vacuum booster is provided as a booster device (assistance device), the starting point (timing) of application of auxiliary pressure is the jump-in of the negative pressure booster (characteristic that the assist force of the booster device increases stepwise from zero, It is desirable to coincide with the point (timing) where the occurrence (also called jumping) occurs. When two types of boosting actions with different operating principles, ie, a boosting action due to negative pressure (assistance action) and a boosting action due to auxiliary pressure (assistance action) are combined, the boosting action (assistance action) starts to occur. By making the braking operation amount (starting point) the same, a sense of incongruity with respect to the braking operation can be suppressed. As described above, the means for determining the auxiliary pressure reference value SP # o corresponds to the “reference amount determining means”.

<Pressure correction calculation>
Next, the pressure correction calculation will be described. When the vehicle turns, load movement in the left-right direction occurs, and the ground contact load of the turning inner wheel decreases. In addition, load movement in the front-rear direction occurs during braking, and the ground load on the rear wheel decreases. For this reason, at the time of braking in a turning state, the ground load on the rear wheel inside the turning is particularly reduced, and it may be difficult to ensure the rear wheel cornering force.

  Therefore, the turning inner wheel where the ground load is reduced is selected, and the increase of the braking pressure is limited. That is, the wheel cylinder pressure of the selected wheel (selected wheel) is limited to a value lower than the braking pressure in the braking pipe including the selected wheel (corresponding to the “pressure increase limiting control”). On the other hand, when the pressure increase is limited, the total braking force acting on the vehicle body decreases. Therefore, in order to increase the braking force of the wheels other than the selected wheel, the auxiliary pressure for the brake pipe including the wheels other than the selected wheel is corrected to be increased more than the reference value SP # o (corresponding to the “auxiliary hydraulic pressure increase control”). ).

  Using the turning state amount Tc, the braking operation amount Sbs for starting the pressure increase restriction control is determined based on the characteristics of FIG. Here, the turning state amount Tc is calculated based on the detection result of the turning state amount detection means TC (for example, the lateral acceleration sensor GY). More specifically, the turning state amount Tc is a state amount representing the turning motion of the vehicle (corresponding to the “turning state amount”), the steering wheel operation angle, the steering wheel (front wheel) steering angle, and the lateral acceleration. And a value calculated based on at least one of yaw rate.

  When the turning state amount Tc is equal to or less than the predetermined value Tcp, the pressure increase restriction control of the turning inner wheel is not performed. When the turning state amount Tc becomes larger than the predetermined value Tcp, the braking operation amount (restriction start braking operation amount) Sbs for starting the pressure increase restriction control of the selected wheel (turning inner wheel) according to the turning state amount Tc is set. Is set. Specifically, the limit start braking operation amount Sbs is set to a smaller value as the turning state amount Tc is larger.

  The restriction start braking operation amount Sbs can be set to a different value when the selected wheel is the front wheel and when the selected wheel is the rear wheel. When the selected wheel is a rear wheel, it is more desirable to secure a cornering force. Therefore, the restriction start braking operation amount Sbs can be set to a lower value than when the selected wheel is a front wheel.

  When the vehicle body speed is high, more directional stability of the vehicle is desired. Therefore, the restriction start braking operation amount Sbs can be set according to the vehicle body speed Vx. Specifically, the limit start braking operation amount Sbs can be set to a smaller value as the vehicle body speed is higher. The vehicle body speed can be calculated using the detection value of the wheel speed sensor WS **.

  Since the vehicle body deceleration is a value that changes according to the braking operation amount Bs, the vehicle body deceleration (restriction start deceleration) Sgx that starts the pressure increase restriction control using the vehicle body deceleration Gx instead of the braking operation amount Bs. Can be calculated. The vehicle body deceleration Gx can be calculated using the detection value of the longitudinal acceleration sensor GX or the wheel speed sensor WS **.

  The upper limit value Zs ** of the pressure increasing gradient (increasing gradient) of the braking pressure Pw ** can be determined using the turning state amount Tc based on the characteristics of FIG. Thereby, the upper limit value Zs ** of the pressure increasing gradient (increasing gradient) is set to a smaller value as the turning state amount Tc is larger.

  When the vehicle body speed is high, more directional stability of the vehicle is desired. Therefore, the pressure increase gradient upper limit value Zs ** can be set according to the vehicle body speed Vx. Specifically, the pressure increase gradient upper limit value Zs ** is set to a smaller value as the vehicle body speed is higher. Further, when the selected wheel is a rear wheel, it is more desirable to secure a cornering force. Therefore, the pressure increase gradient upper limit value Zs ** can be set to a smaller value than when the selected wheel is a front wheel. .

  The pressure increase gradient upper limit value Zs ** is performed by controlling the open / close time of the pressure increase limiting means (for example, the inlet valve IV **) (so-called pulse pressure increase control). When the pressure increase restricting means is an ON / OFF solenoid valve, a pressure fluctuation accompanying opening / closing of the solenoid valve occurs. Therefore, at the time of pressure increase restriction control, the pressure increase gradient upper limit value Zs ** is set to “0 (maintenance of braking pressure)” to hold the solenoid valve (inlet valve) in the closed position and It is preferable to prevent kickback.

  As shown in FIG. 9, the limit pressure Ps ** of the braking pressure Pw ** of the selected wheel (turning inner wheel) can be set based on the turning state amount Tc. In this case, when the braking pressure Pw ** of the selected wheel reaches the limit pressure Ps **, the pressure increase limit control (that is, the pressure increase gradient limit or the pressure hold) is started.

  As the braking pressure Pw **, the detection result (actual wheel cylinder braking pressure Pw ** a) of the pressure sensor P ** provided in each wheel can be used. Further, the braking pressure Pw ** can be obtained using the detection result (actual braking pipe pressure Ph #) of the pressure sensor PH # provided in the brake pipe on the pump discharge side. The pressure sensors P ** and PH # can be omitted. In this case, the braking pressure Pw ** is estimated based on the behavior (transition) of the wheel speed, the operating state of the solenoid valve, and the like.

  The restriction start braking operation amount Sbs (or restriction start deceleration Sgx) shown in FIG. 7 and the pressure increase restriction pressure Ps ** shown in FIG. 9 are threshold values corresponding to the start of the pressure increase restriction control. That is, when the braking operation amount Bs, the vehicle body deceleration Gx, or the braking pressure Pw ** is a value corresponding to a region above the characteristic line (solid line or broken line) shown in the figure, the pressure increase limiting control is performed. Is executed. On the other hand, the pressure increase gradient upper limit value Zs ** in FIG. 8 is a value for limiting the pressure increase amount (pressure increase gradient) after the start of the pressure increase restriction control.

  Next, the increase correction from the reference value SP # o of the auxiliary pressure (that is, the auxiliary hydraulic pressure increase control) in the brake pipe including the wheels other than the selected wheel will be described with reference to FIG.

  The auxiliary pressure of the brake piping system including the selected wheel can be increased with respect to the reference value SP # o. When the turning state amount Tc is equal to or less than the predetermined value Tcw, the correction coefficient K # = 1 is set. That is, the auxiliary hydraulic pressure increase control is not performed. On the other hand, when the turning state amount Tc becomes larger than the predetermined value Tcw, the auxiliary pressure is increased from the reference value SP # o. Therefore, the correction coefficient K # is set to a value larger than “1” based on the turning state amount Tc. To do. Specifically, the correction coefficient K # is set to a larger value (> 1) as the turning state amount Tc is larger. Alternatively, the correction coefficient K # can be set to be changed stepwise from “1” to a predetermined value (> 1) in the turning state amount at which the pressure increase limiting control is started.

  In the case of front and rear piping, when the selected wheel is a turning inner front wheel, the auxiliary pressure of the front wheel system is increased. Further, in the case of diagonal piping, when the selected wheel is a turning inner rear wheel, the auxiliary pressure of the piping system including the turning outer front wheel is increased. That is, the auxiliary pressure of the brake piping system including the selected wheel can be increased with respect to the reference value SP # o. As a result, the relationship between the braking operation and the vehicle deceleration is kept constant, and a yaw moment is generated that stabilizes the vehicle due to the braking force difference between the left and right wheels. On the other hand, the auxiliary pressure of the brake piping system not including the selected wheel can be increased with respect to the reference value SP # o.

  The auxiliary pressure increase amount of the brake piping system including the selected wheel can be set higher than the auxiliary pressure increase amount of the brake piping system not including the selected wheel. In addition, the correction coefficient K # can be set based on the vehicle body speed Vx. Specifically, as the vehicle body speed Vx is higher, it is desired to ensure the directional stability of the vehicle. Therefore, the correction coefficient K # is set to a larger value (> 1).

  One of the braking pressure increase restriction (pressure increase restriction control) and the auxiliary pressure increase (auxiliary hydraulic pressure increase control) may be started first, but it is preferable that the braking pressure is started almost simultaneously.

  The turning state amount Tc is a state amount that changes every moment depending on the braking operation state. Instead of the turning state amount Tc, the turning state amount Tco at the start of the braking operation can be used. Also, the vehicle body speed Vx is a state quantity that changes every moment depending on the braking operation state, but the vehicle body speed Vxo at the start of braking can be used instead of the vehicle body speed Vx.

  Changes in the ground load due to turning and vehicle deceleration appear as slipperiness of the wheels. Therefore, instead of the turning state amount Tc, the pressure increase limiting control can be executed based on a value representing the slipperiness of the turning inner wheel (corresponding to the “wheel state amount”). As a value representing the slipperiness of the wheel (hereinafter, also referred to as a wheel state quantity Py **), for example, the wheel slip speed Sl ** obtained from the difference between the vehicle body speed and the wheel speed, or the wheel slip speed is represented by the vehicle body. The wheel slip ratio Sr ** divided by the speed can be used. Further, the degree of difference in wheel slip speed or wheel slip rate (for example, difference, ratio, etc.) between the wheels can be used as the wheel state quantity.

  The wheel state quantity Py ** is calculated using a known road surface μ gradient (see, for example, Japanese Patent Laid-Open No. 2001-133390, US6522968) and a wheel grip degree (see, for example, Japanese Patent Laid-Open No. 2003-312465, US6895317). You can also. When the wheel state quantity Py ** of the selected wheel (turning inner wheel) becomes larger than a predetermined value (when the turning inner wheel becomes slippery), the pressure increase restriction control (start of pressure increase restriction, In addition, the pressure increase gradient is limited and the pressure is maintained) based on the wheel state quantity Py **. In addition, the auxiliary pressure for the brake piping system including the wheels other than the selected wheel is increased from the reference value SP # o based on the wheel state quantity Py **.

  In the pressure increase restriction control, the turning state amount Tc itself or the wheel state amount Py ** itself can be used as a condition for starting the pressure increase restriction. That is, the pressure increase restriction control is started and executed when the turning state amount Tc becomes equal to or greater than the threshold value Tck during braking. Alternatively, the pressure increase limiting control is started / executed when the wheel state quantity Py ** becomes equal to or greater than the threshold value Pyk during braking. The threshold value Tck for the turning state amount and the threshold value Pyk for the wheel state amount can be fixed, but can also be set based on the vehicle body speed Vx (or the vehicle body speed Vxo at the start of braking). In this case, these threshold values are set to smaller values as the vehicle body speed Vx increases.

  As described above, in the pressure increase restriction control, the restriction start braking operation amount Sbs is based on any one of the turning state amount Tc (or the turning state amount Tco at the start of braking) and the wheel state amount Py **. Any one of the restriction start vehicle deceleration Sgx and the pressure increase restriction pressure Ps ** is set as the control start condition. Alternatively, any one of the turning start amount and the wheel state amount is set as a control start condition. Further, the pressure increase gradient upper limit value Zs ** is set based on any one of the turning state amount Tc (or the turning state amount Tco at the start of braking) and the wheel state amount Py **. The limit start braking operation amount Sbs, the limit start vehicle deceleration Sgx, the pressure increase limit pressure Ps **, the turning state amount threshold value Tck, the wheel state amount threshold value Pyk, and the pressure increase gradient upper limit value Zs ** are the vehicle body speed Vx. Can be set based on.

<Calculation of auxiliary pressure target value SP # t>
As described above, the auxiliary pressure in the piping system is increased by the auxiliary hydraulic pressure increase control in order to compensate for the pressure reduced by the pressure increase limiting control. A target value of the auxiliary pressure (corresponding to the “auxiliary hydraulic pressure target amount”, hereinafter simply referred to as target value SP # t) is calculated based on the reference value SP # o and the correction coefficient K # (correction value). Is done. The target value SP # t is set to a value that is increased and corrected with respect to the reference value SP # o so that the relationship between the braking operation and the vehicle deceleration is maintained constant.

  The relationship SP # t = K # · Fnc (Bs) is established. Here, K # is the correction coefficient described above for each brake piping system, and is calculated based on the turning state amount Tc (or the wheel state amount Py **) as described above (see FIG. 10). . Fnc (Bs) is a function or table representing the auxiliary pressure reference value SP # o with the braking operation amount Bs as an argument, and is set with characteristics as shown in FIGS. 4 to 6, for example. As described above, the means for determining the auxiliary pressure target value SP # t in this way corresponds to the “target amount determining means”.

<Drive means>
The driving means DRa adjusts the auxiliary pressure applied to the pressure generated by the first pressure generating means (master cylinder M) to adjust the wheel cylinder pressure Pw **, so that the second pressure generating means (electric motor / pump) And drive control of the pressure adjusting means (linear pressure regulating valve). That is, based on the auxiliary pressure target value SP # t calculated as described above, the rotation of the electric motor M and the opening / closing of the linear pressure regulating valve LV # (linear solenoid valve) are controlled.

  The drive means DRa controls the electric motor M based on the auxiliary pressure target value SP # t so that the rotation speed is equal to or higher than the rotation speed that can supply the auxiliary pressure target value SP # t. Based on the detection result of the detection means BS (for example, master cylinder pressure Pm #) and the auxiliary pressure target value SP # t, the pressure target value Ph # t of each piping system (or the wheel pressure target value Pw ** t). ) Is calculated, and based on these, the current value for driving the linear pressure regulating valve LV # is determined, and the linear pressure regulating valve LV # is controlled.

  When each piping system is provided with a pressure sensor PH # (or pressure sensor P ** for each wheel), the actual pressure (Ph # a or Pw ** a) detected by the pressure sensor is the pressure target. Feedback control is performed so as to match the value. The pressure sensors PH # and P ** can be omitted. In this case, the pressure can be estimated based on the behavior (transition) of the wheel speed, the operating state of the valves (linear pressure regulating valve, inlet valve, and outlet valve).

  The inlet valve and outlet valve drive means DRb drives and controls the inlet valve based on the characteristics shown in FIGS. 7 to 9 and FIG. 11 to limit the increase in the braking pressure. When the pressure increase restriction control in which the execution start is determined by the characteristics shown in FIG. 7 or FIG. 9 is permitted, the duty ratio Dt ** for driving the inlet valve is determined based on the characteristics of FIG.

  The duty ratio Dt ** is determined based on the pressure increase gradient upper limit value Zs ** determined with the characteristics shown in FIG. Here, the duty ratio Dt ** = 1 represents a state where power is always supplied. In this case, the inlet valve is maintained in the closed position, and the wheel cylinder pressure Pw ** is maintained at the current pressure. The duty ratio Dt ** = 0 represents a non-energized state. In this case, the inlet valve is maintained in the open position. By controlling the duty ratio Dt **, the pressure increasing gradient of the wheel cylinder pressure Pw ** is limited to the pressure increasing gradient upper limit value Zs ** or less. That is, the duty ratio Dt ** is determined based on the pressure increase gradient upper limit value Zs **, and the pressure increase limit control is achieved by pressure holding or so-called pulse pressure increase.

《Brake control based on ground load》
The contact load acting on each wheel is obtained, and based on these, the pressure increase limiting control and the auxiliary hydraulic pressure increase control can be performed. Hereinafter, the braking control based on the ground load will be described with reference to FIG.

  The ground load can be calculated based on the inertial force acting on the vehicle body. Since the result of the inertial force acting on the vehicle body appears as the longitudinal acceleration Gx and the lateral acceleration Gy, the ground load of each wheel is estimated using the longitudinal acceleration Gx and the lateral acceleration Gy as shown below. Can do.

Ground contact load of turning outer front wheel FZsf = FZfo + Xfnc (Gx) + Yfnc (Gy)
Ground contact load of turning front wheel FZuf = FZfo + Xfnc (Gx) -Yfnc (Gy)
Ground contact load of turning rear rear wheel FZsr = FZro-Xfnc (Gx) + Yfnc (Gy)
Ground contact load of turning inner rear wheel FZur = FZro-Xfnc (Gx) -Yfnc (Gy)

  Here, FZfo and FZro are static ground loads of the front and rear wheels, Xfnc (Gx) is a function representing load movement in the front-rear direction using Gx as an argument, and Yfnc (Gy) is a left-right direction using Gy as an argument. It is a function representing load movement. Xfnc (Gx) and Yfnc (Gy) can be obtained from vehicle specifications or can be obtained experimentally.

  The total braking force BFv necessary for decelerating the vehicle is calculated according to the relationship of BFv = Zfnc (Bs) based on the braking operation amount Bs. Here, Zfnc (Bs) is a function having Bs as an argument. The total braking force BFv can be set with a characteristic that is substantially proportional to the braking operation amount Bs.

  The required value Preq ** of each wheel braking pressure is calculated according to the relationship of Preq ** = Kb ** · BFv · (FZ ** / Ms) based on the total braking force BFv and the ground load FZ **. . Here, Kb ** is a conversion coefficient from braking force to braking pressure, and is a value obtained from a wheel radius, a brake effective diameter, a pad friction coefficient, a wheel cylinder pressure receiving area, and the like. Ms is a vehicle weight. As a result, the braking pressure requirement value Preq ** of each wheel is distributed according to the ground load, so that the braking load (ratio of the braking force to the ground load) of each wheel becomes uniform.

  Based on the required value Preq ** of each wheel, the required value Prequ for the turning inner wheel and the required value Preqs for the outer turning wheel are selected.

  Based on the deviation ΔPwu between the required value Prequ of the turning inner wheel and the actual pressure Pw ** a, the start condition of the pressure increase limiting control and the pressure increase gradient after the control start are determined, and the duty ratio Dt ** is determined. It is determined. Then, the inlet valve IV ** of the turning inner wheel is controlled based on the duty ratio Dt **. The start condition of the pressure increase limiting control, the pressure increase gradient after the control start, and the characteristic (table) for determining the duty ratio Dt ** are shown in FIG. 7 to FIG. 9 and FIG. It can be obtained by replacing “Tc” with “pressure deviation ΔPwu”.

  Similarly, a correction coefficient Kz # for performing auxiliary hydraulic pressure increase control is calculated based on the deviation ΔPws between the required value Preqs of the turning outer wheel and the actual pressure Pw ** a. The characteristic (table) for calculating the correction coefficient Kz # can be obtained by substituting “swing state quantity Tc” with “pressure deviation ΔPws” in FIG. It is also possible to calculate a target value (= Preqs−Pm #) of auxiliary pressure that can achieve the required value Preqs of the turning outer wheel, and set this as the target value SP # t.

  In the following, regarding the actions and effects obtained by the execution of the pressure increase limiting control and the auxiliary hydraulic pressure increase control described above, the type of brake pipe, the wheel subject to the pressure increase limiting control (= selected wheel), the auxiliary hydraulic pressure increase A description will be given for each combination of braking pipes to be controlled. It should be noted that for any of the following combinations, “the relationship between the braking operation and the vehicle deceleration can be maintained substantially constant, and the left / right difference in braking force (not only the left / right difference between the left and right front wheels and the left and right rear wheels (Including the left / right difference between the left wheel and the right wheel located on the diagonal line) produces an outward turning yaw moment that improves directional stability ”. Therefore, in the following, only additional actions and effects will be mentioned.

<For front and rear piping>
First, the case of front and rear piping will be described.

<When the selected wheel is the front front wheel only>
1. When the target of auxiliary hydraulic pressure increase control is only the front wheel system (when the system includes the selected wheel)
In this case, since the auxiliary pressure of the rear wheel system is not increased and corrected, the cornering force of the rear wheel can be secured, and the directional stability of the vehicle is improved.
2. When the target of auxiliary hydraulic pressure increase control is only the rear wheel system (when the system does not include the selected wheel)
In this case, the braking load on each wheel can be made substantially uniform by slightly increasing and correcting the auxiliary pressure of the rear wheel system.
3. When the target of auxiliary hydraulic pressure increase control is both the front wheel and rear wheel systems (in the case of systems including selected wheels)
In this case, the braking load of each wheel can be made substantially uniform by slightly increasing and correcting the auxiliary pressures of the wheels (three wheels) other than the selected wheel. Therefore, the cornering force of each wheel can be ensured uniformly.

<When the selected wheel is only the rear wheel on the inside>
1. When the target of auxiliary hydraulic pressure increase control is only the front wheel system (when the system does not include the selected wheel)
In this case, since the auxiliary pressure of the rear wheel system is not increased and corrected, the cornering force of the rear wheel can be secured. Moreover, the braking load of each wheel can be made substantially uniform by slightly increasing and correcting the auxiliary pressure of the front wheel system.
2. When the target of auxiliary hydraulic pressure increase control is both the front wheel and rear wheel systems (in the case of systems including selected wheels)
In this case, the braking load of each wheel can be made substantially uniform by slightly increasing and correcting the auxiliary pressures of the wheels (three wheels) other than the selected wheel. Therefore, the cornering force of each wheel can be ensured uniformly.

<When the selected wheel is the front and rear wheels inside the turn>
1. When the target of auxiliary hydraulic pressure increase control is only the front wheel system (when the system includes the selected wheel)
In this case, since the auxiliary pressure of the rear wheel system is not increased and corrected, the cornering force of the rear wheel can be secured, and the directional stability of the vehicle is improved.
2. When the target of auxiliary hydraulic pressure increase control is both the front wheel and rear wheel systems (in the case of systems including selected wheels)
In this case, the braking load of each wheel can be made substantially uniform by slightly increasing and correcting the auxiliary pressures of the wheels (two wheels) other than the selected wheel. Therefore, the cornering force of each wheel can be ensured uniformly.

<Diagonal piping>
Next, the case of diagonal piping will be described.

<When the selected wheel is the front front wheel only>
1. When the target of the auxiliary hydraulic pressure increase control is a system that does not include the selected wheel In this case, it is possible to increase and correct the auxiliary pressure of the turning outer front wheel where the ground contact load increases most.
2. When the target of auxiliary fluid pressure increase control is both the first and second systems (in the case of systems including selected wheels)
In this case, the braking load of each wheel can be made substantially uniform by slightly increasing and correcting the auxiliary pressures of the wheels (three wheels) other than the selected wheel. Therefore, the cornering force of each wheel can be ensured uniformly.

<When the selected wheel is only the rear wheel on the inside>
1. In the case where the target of the auxiliary hydraulic pressure increase control is a system including the selected wheel In this case, an increase in the braking pressure of the turning inner rear wheel where the ground contact load is reduced is limited, and a cornering force of the rear wheel can be secured. Furthermore, it is possible to increase and correct the auxiliary pressure of the turning front front wheel where the ground contact load increases most.
2. In the case where the target of the auxiliary hydraulic pressure increase control is a system that does not include the selected wheel. In this case, an increase in the braking pressure of the turning inner rear wheel that reduces the ground contact load is limited, and a cornering force of the rear wheel can be secured.
3. When the target of auxiliary fluid pressure increase control is both the first and second systems (in the case of systems including selected wheels)
In this case, an increase in the braking pressure of the turning inner rear wheel where the ground contact load is most reduced is limited, and a cornering force of the rear wheel can be secured. By slightly increasing and correcting the auxiliary pressures of the wheels other than the selected wheel (three wheels), the braking load on each wheel can be made substantially uniform. Therefore, the cornering force of each wheel can be ensured uniformly.

<When the selected wheel is the front and rear wheels inside the turn>
1. In the case where the target of the auxiliary hydraulic pressure increase control is a system including the turning outer front wheel In this case, the increase of the braking pressure of the turning inner rear wheel where the ground contact load is reduced is limited, and the cornering force of the rear wheel can be secured. Furthermore, it is possible to increase and correct the auxiliary pressure of the turning front front wheel where the ground load increases most.
2. When the target of the auxiliary hydraulic pressure increase control is both the first and second systems (in the case of the system including the selected wheel)
In this case, the auxiliary pressure of the turning outer wheel (two wheels) where the ground contact load increases can be increased and corrected. Further, an increase in the braking pressure of the turning inner wheel (two wheels) in which the ground load decreases is limited. And the braking load of each wheel can be made substantially uniform, and the cornering force of each wheel can be ensured uniformly.

  As described above, when the pressure increase is limited by selecting the rear wheel on the inside of the turn, the cornering force of the rear wheel can be secured and the directional stability of the vehicle can be maintained.

  Further, the decrease in the braking force accompanying the pressure increase limiting control is compensated by the braking force of the unselected wheel. Since this compensation can be shared by increasing and correcting the auxiliary pressures of both the piping systems, the braking load of each wheel (generation of braking force with respect to the ground load) can be made substantially uniform.

  Also, in the case of front and rear piping, the selected wheel is the turning inner rear wheel, and the auxiliary pressure of the front wheel system is increased and corrected, so that the cornering force of the rear wheel can be secured, and the turning of the vehicle by reducing the cornering force of the front wheel Inward entrainment can be suppressed.

  Also, in the case of front and rear piping, the selected wheel is the turning inner front and rear wheels, and the auxiliary pressure of the front wheel system is increased and corrected, so that the cornering force of the rear wheels can be secured, and the direction of the vehicle depends on the braking force difference between the left and right front wheels Stability can be improved.

  In the case of diagonal piping, the cornering force of the rear inner wheel can be secured and the grounding load can be secured by increasing and correcting the auxiliary pressure of the brake pipe including the rear inner wheel as the selected wheel as the inner rear wheel. The directional stability of the vehicle can be improved by increasing the braking force of the outer front wheel that is most increased.

  In the case of diagonal piping, the cornering force of the rear inner wheel can be secured by increasing and correcting the auxiliary pressure of both braking pipes with the selected wheel as the inner rear wheel, and the braking load on each wheel can be largely reduced. It can be uniform.

<When the selected wheel is the rear wheel>
As described above, the ground load varies due to turning, but load movement from the rear wheels to the front wheels also occurs due to braking (deceleration). For this reason, the cornering force of the rear wheels is reduced, and the vehicle may be fluttered even when braking in a straight line. This phenomenon is likely to occur when the vehicle speed is high. Therefore, at least one of the rear wheels can be a selected wheel, and pressure increase of the selected wheel can be limited.

  When the braking pipe is a front and rear pipe, the pressure increase restriction is performed by the inlet valves IVrl and IVrr. Then, the auxiliary pressure target value SPft of the front wheel system is increased and corrected with respect to the reference value SPfo. The conditions (control parameters) for the pressure increase limiting control and the auxiliary hydraulic pressure increase control are performed based on the wheel state quantity Py ** with the characteristics shown in FIGS. Further, a threshold value for the wheel state quantity is set, and when the wheel state quantity reaches this threshold value, the pressure increase limiting control can be started / executed. The control of the inlet valve is performed based on the duty ratio Dt ** determined using the table shown in FIG.

  When the brake pipe is a diagonal pipe, the pressure increase restriction is performed by the inlet valves IVrl and IVrr. Then, the auxiliary pressure target values SP1t and SP2t of both the first and second systems are increased and corrected with respect to the reference values SP1o and SP2o. The conditions (control parameters) for the pressure increase limiting control and the auxiliary hydraulic pressure increase control are performed based on the wheel state quantity Py ** with the characteristics shown in FIGS. Further, a threshold value for the wheel state quantity is set, and when the wheel state quantity reaches this threshold value, the pressure increase limiting control can be started / executed. The control of the inlet valve is performed based on the duty ratio Dt ** determined using the table shown in FIG.

  Further, since vehicle flutter during braking is more likely to occur as the vehicle body speed increases, as shown in FIG. 13, the start condition for the pressure increase restriction (the braking operation amount Sbs at which the pressure increase restriction is started, the pressure increase restriction is started). Vehicle deceleration Sgx, pressure Ps ** at which pressure increase restriction is started, or braking start wheel state quantity Pyj (wheel state quantity threshold) is set to vehicle body speed Vx (or vehicle body speed Vxo at the start of braking). ). As the vehicle body speed increases, the rear wheel braking pressure increase limit is started and executed at a lower braking pressure or a smaller braking operation amount, so that the cornering force of the rear wheel can be stably secured, and the vehicle Can be stably suppressed.

《Action ・ Effect》
Next, the operation and effect of the present invention will be described with reference to FIGS. 14 and 15. As shown in FIG. 14, the turning inner wheel (particularly the turning inner rear wheel) is selected, and the braking operation amount Bs is determined based on the turning state amount Tc or the like to the “value Sbs for starting the pressure increase restriction”. When it reaches (point Q), the pressure increase of the selected wheel is limited by the pressure increase limiting means (inlet valve).

  At this time, the braking pressure Pw ** of the selected wheel is maintained (see the characteristic line (1)) or increased with the pressure increase gradient limited (see the characteristic line (2)). Furthermore, holding and pressure increasing may be alternately performed as shown by the characteristic line (3) by combining holding and pressure increasing gradient restriction. When the inlet valve is duty-controlled and the pressure increase gradient is limited by opening / closing the inlet valve, kickback to the brake pedal occurs. On the other hand, such a kickback can be suppressed by including the holding period as in the characteristic lines (1) and (3).

  When the pressure increase restriction control is performed on the selected wheel, the auxiliary pressure is increased and corrected from the reference value (the auxiliary pressure when the pressure increase restriction means does not restrict the pressure increase during straight braking). That is, as shown in FIG. 15, when the braking operation amount Bs reaches the restriction start braking operation amount Sbs, the auxiliary hydraulic pressure increase control is started and executed. As a result, the braking pressure Pw ** increases in the non-selected wheels.

  The total braking force is reduced by the pressure increase limiting control for the selected wheel. This decrease in the total braking force can be compensated by the auxiliary hydraulic pressure increase control. Thereby, the increase characteristic of the vehicle deceleration with respect to the amount of braking operations can be maintained substantially constant.

  Further, since the turning inner wheel is selected as the target of the pressure increase restriction control, a braking force difference is generated between the left and right wheels by the pressure increase restriction control and the auxiliary hydraulic pressure increase control. As a result, an outward turning yaw moment is generated, and the directional stability of the vehicle is improved.

  FIG. 16 and FIG. 17 are time charts showing examples of the pressure increase restriction pattern of the pressure increase restriction control when the above embodiment is applied. In FIG. 16, the braking operation is started at time t0, and the pressure increase limiting control and the auxiliary hydraulic pressure increase control are started when the braking operation amount Bs reaches the limit start braking operation amount Sbs (= Bs1) at time t1. An example is shown in which a brake pedal return operation is performed during the execution of the pressure increase limiting control and the auxiliary hydraulic pressure increase control.

  The pressure Ph # of the piping system including the selected wheel is maintained at the auxiliary pressure reference value with the characteristics of ab-c1-d1-ef when this piping system is not subject to the auxiliary hydraulic pressure increase control. If this piping system is the target of the auxiliary hydraulic pressure increase control, it has a characteristic of ab-c2-d2-ef, and is a value larger than the auxiliary pressure reference value between times t1 and t2. It changes in. Time t2 corresponds to a point in time when the turning state amount Tc, which decreases as the vehicle decelerates, reaches a value Tcw (see FIG. 10).

  The pressure Ph # of the piping system including the wheels other than the selected wheel has the characteristics of rs-u2-v2-w-x, and the times t1 to t2 since this piping system is the target of the auxiliary hydraulic pressure increase control. During this period, the value is larger than the auxiliary pressure reference value.

  In the pressure increase limiting control, the braking pressure Pw ** of the selected wheel is ab-c3-d3- when the pressure increase gradient is limited (corresponding to the characteristic line (2) in FIG. 14). When it changes with the characteristic of ef and this pressure is maintained (corresponding to the characteristic line (1) in FIG. 14), it changes with the characteristic of ab-d4-ef. That is, in this case, the braking pressure Pw ** of the selected wheel is reduced (d3-e or d4-e) in accordance with the return operation of the brake pedal.

  On the other hand, the braking pressure Pw ** of the selected wheel may be held during the brake pedal return operation. In this case, the braking pressure Pw ** of the selected wheel changes with the characteristic of d3-g1 (g2) -e or d4-h1 (h2) -e. As a result, the opening / closing operation of the valve is limited as much as possible, so that the noise associated with the opening / closing operation of the valve can be suppressed.

  Thus, when the braking pressure Pw ** of the selected wheel is held during the brake pedal return operation, the inlet valve IV ** of the selected wheel can be held in the closed position. For example, in FIG. 14, when the return operation of the brake pedal is started at the braking operation amount Bs = Bsc, the inlet valve IV ** is held in the closed position, so that the braking pressure Pw ** of the selected wheel is at the point R. Corresponding pressure is maintained.

  When the state corresponding to the point S in FIG. 14 (the state corresponding to the point g1 (g2) or the point h1 (h2) in FIG. 16) is reached, the pressure Ph # of the piping system including the selected wheel is selected. Is equal to the braking pressure Pw **. Thereafter, since the check valve CV ** (see FIG. 2) is opened, the braking pressure Pw ** of the selected wheel decreases while taking the same value as the pressure Ph # that is still decreasing. After the decreasing pressure Ph # matches the braking pressure Pw ** of the selected wheel (that is, in the state where Ph # = Pw ** by opening the check valve CV **), the inlet valve IV ** The closed position is changed to the open position.

  Here, if the inlet valve IV ** is changed from the closed position to the open position in the state of Ph #> Pw ** during the return operation of the brake pedal, a kickback to the brake pedal occurs. On the other hand, as described above, the inlet valve IV ** is changed from the closed position to the open position after the check valve CV ** is opened (that is, in the state of Ph # = Pw **). Such kickback can be prevented from occurring.

  In FIG. 17, the braking operation is started at time t0, and when the braking operation amount Bs reaches the restriction start braking operation amount Sbs (= Bs1) at time t1, the pressure increase limiting control and the auxiliary hydraulic pressure increase control are started. Further, an example is shown in which the turning state amount Tc is sufficiently reduced by the deceleration of the vehicle before the brake pedal return operation is started during the execution of the pressure increase limiting control and the auxiliary hydraulic pressure increase control.

  As in FIG. 16, when the piping system including the selected wheel is not subject to the auxiliary hydraulic pressure increase control, the pressure Ph # changes while maintaining the auxiliary pressure reference value with the characteristic indicated by the broken line. When the piping system is the target of the auxiliary hydraulic pressure increase control, it changes with a value larger than the auxiliary pressure reference value between times t1 and t3 with the characteristic indicated by the alternate long and short dash line. Time t3 corresponds to a point in time when the turning state amount Tc, which decreases as the vehicle decelerates, reaches a value Tcw (see FIG. 10).

  The pressure Ph # of the piping system including the wheels other than the selected wheel is an auxiliary pressure reference between times t1 and t3 with the characteristics of HI-J because this piping system is the target of the auxiliary hydraulic pressure increase control. It changes at a value larger than the value.

  In this case, when the pressure increase gradient is limited in the pressure increase restriction control, the braking pressure Pw ** of the selected wheel may be changed with the characteristic of S-A-B-C-D-R-U. . That is, the braking pressure Pw ** of the selected wheel is returned toward the auxiliary pressure reference value (point D) from time t2 when the increase correction amount of the auxiliary pressure starts to decrease due to the decrease in the turning state amount Tc (increase). )

  Similarly, when the pressure is maintained in the pressure increase limiting control, the braking pressure Pw ** of the selected wheel may be changed with the characteristic of SA-E-D-R-U. That is, the braking pressure Pw ** of the selected wheel is returned toward the auxiliary pressure reference value (point D) from time t2 when the increase correction amount of the auxiliary pressure starts to decrease due to the decrease in the turning state amount Tc (increase). )

  On the other hand, after time t2, the braking pressure Pw ** of the selected wheel may be held. In this case, the braking pressure Pw ** of the selected wheel changes with the characteristics of C-F-U or E-G-U. As a result, the opening / closing operation of the valve is limited as much as possible, so that the noise associated with the opening / closing operation of the valve can be suppressed. In this case as well, the inlet valve IV ** in the closed position is the same as described above after the decreasing pressure Ph # matches the braking pressure Pw ** of the selected wheel (that is, the check valve CV ** is opened). Thus, in the state of Ph # = Pw **, after the time t4 or after the time t5), the closed position is changed to the open position.

  Unlike the brake control device, in which the driver's braking operation and brake torque adjustment, which are called brake-by-wire, are mechanically separated, the brake control in which the master cylinder and the wheel cylinder are connected via fluid In the device (hereinafter also referred to as “hydraulic communication type braking control device”), the operating characteristics of the brake pedal (relationship between the brake pedal stroke and the operating force) are the rigidity of the brake caliper, brake pad, brake piping, etc. Depends on. Therefore, in the hydraulic communication type braking control device, it is desirable to adjust the braking torque while maintaining the communication between the master cylinder and the wheel cylinder as much as possible.

  Here, in the present embodiment, which is a hydraulic communication type braking control device, start / execution of the pressure increase restriction control is performed by opening / closing the inlet valve (with communication / blocking of the master cylinder and the wheel cylinder). The auxiliary hydraulic pressure increase control is executed while maintaining communication between the master cylinder and the wheel cylinder. For this reason, the change of the brake pedal operation characteristic can be suppressed to the minimum.

  The present invention is not limited to the above embodiment, and various modifications can be employed within the scope of the present invention. For example, in the above embodiment, the braking pressure increase limit (pressure increase limit control) and the auxiliary pressure increase (auxiliary hydraulic pressure increase control) are started simultaneously. Here, when the auxiliary pressure of the brake pipe including the selected wheel is increased and corrected, if the pressure increase restriction control (change to the closed position of the inlet valve) is delayed, the brake pressure of the selected wheel temporarily increases. Things can happen. Therefore, the pressure increase limiting control can be started first, and then the auxiliary hydraulic pressure increase control can be started.

  Further, the oversteer tendency during braking (involvement of the inside of the turning circle) becomes prominent when braking is started when the amount of turning state is large (for example, when the lateral acceleration Gy is 0.6 G or more). Conversely, when turning after starting braking, an oversteer tendency is unlikely to occur. Therefore, the pressure increase limiting control and the auxiliary hydraulic pressure increase control can be performed only when braking is started after the vehicle turns (during turning braking).

  The determination of whether or not it is during turning braking can be executed based on the amount of turning state at the time when braking is started. That is, this determination can be performed based on the turning state amount at the time when the braking operation amount reaches a minute predetermined value. When the turning state amount at the start of braking is larger than a predetermined value, the pressure increase restriction control and the auxiliary hydraulic pressure increase control are executed. When the turning state amount at the time of braking is less than the predetermined value, the pressure increase restriction control, And the auxiliary hydraulic pressure increase control is not performed.

  For example, when braking is performed from a straight traveling state and then slaloming is performed, the communication with the wheel cylinder is blocked by the inlet valve, so that the brake pedal operation characteristics change every moment. However, when the amount of turning state at the start of braking is less than or equal to a predetermined value, the operation characteristic fluctuation can be prevented by prohibiting execution of the pressure increase limiting control and the auxiliary hydraulic pressure increase control.

  In addition, in the above embodiment, the correction value of the auxiliary pressure is used as a correction coefficient, and the auxiliary pressure is adjusted by multiplying the correction value by the reference value. It is also possible to adjust the auxiliary pressure by calculating (correcting pressure) and increasing or decreasing it with respect to the reference value.

It is a figure showing the whole brake control device composition for vehicles concerning an embodiment of the present invention. It is the figure which showed the detail of the brake fluid pressure circuit in the whole structure shown in FIG. It is a functional block diagram when the apparatus shown in FIG. 1 performs braking control. 6 is a graph showing a table that defines the relationship between the braking operation amount and the auxiliary pressure reference value, which is referred to by the apparatus shown in FIG. 1 in the case of front and rear piping. 6 is a graph showing another table that defines the relationship between the braking operation amount and the auxiliary pressure reference value, which is referred to by the apparatus shown in FIG. 1 in the case of front and rear piping. 6 is a graph showing a table that defines the relationship between the braking operation amount and the auxiliary pressure reference value, which is referred to by the apparatus shown in FIG. 1 in the case of diagonal piping. It is the graph which showed the table which prescribes | regulates the relationship between the turning state quantity and the restriction | limiting start braking operation quantity which the apparatus shown in FIG. 1 refers. It is the graph which showed the table which prescribes | regulates the relationship between the turning state quantity and the pressure increase gradient upper limit which the apparatus shown in FIG. 1 refers. It is the graph which showed the table which prescribes | regulates the relationship between the turning state quantity and the pressure increase limitation pressure which the apparatus shown in FIG. 1 refers. It is the graph which showed the table which prescribes | regulates the relationship between a turning state quantity and a correction coefficient which the apparatus shown in FIG. 1 refers. It is the graph which showed the table which prescribes | regulates the relationship between the pressure increase gradient upper limit and the duty ratio of an inlet valve drive current which the apparatus shown in FIG. 1 refers. It is a functional block diagram at the time of performing braking control based on the ground load of each wheel. It is the graph which showed the table which prescribes | regulates the relationship between a vehicle speed and a restriction | limiting start braking operation amount (pressure increase restriction pressure). It is the graph which showed an example of the change of the braking pressure of a selection wheel when braking control is performed by the device shown in FIG. 3 is a graph showing an example of a change in braking pressure of a non-selected wheel when braking control is executed by the device shown in FIG. 1. 3 is a time chart showing an example of a change pattern of each physical quantity when braking control is executed by the device shown in FIG. 1. 6 is a time chart showing another example of a change pattern of each physical quantity when braking control is executed by the device shown in FIG. 1.

Explanation of symbols

  MC ... Master cylinder, VB ... Vacuum booster, HP # ... Pump, M ... Motor, PM # ... Master cylinder pressure sensor, LV # ... Linear solenoid valve, WC ** ... Wheel cylinder, IV ** ... Inlet valve, CV * * Check valve

Claims (7)

Four wheel braking devices that respectively apply braking torque corresponding to the braking hydraulic pressure supplied to the wheel cylinders of the four front, rear, left, and right wheels of the vehicle to the corresponding wheels;
A first hydraulic pressure generating device having two hydraulic pressure generating chambers each generating a hydraulic pressure amount corresponding to a braking operation amount by a driver of the vehicle;
A first hydraulically connecting one of the two hydraulic pressure generating chambers to two of the four wheel braking devices corresponding to the left and right front wheels or two corresponding to the left front wheel and the right rear wheel. Hydraulic piping,
A second hydraulically connecting the other of the two hydraulic pressure generating chambers to two of the four wheel braking devices corresponding to the left and right rear wheels or two corresponding to the right front wheel and the left rear wheel. Hydraulic piping of
A power-driven second hydraulic pressure generator for generating an auxiliary hydraulic pressure to be added to the hydraulic pressure amount generated by the first hydraulic pressure generator in each of the first and second hydraulic pressure pipes; ,
Braking operation amount detection means for detecting the braking operation amount;
State quantity acquisition means for acquiring a turning state quantity representing the turning motion of the vehicle;
In the turning state of the vehicle, at least one of the turning inner front and rear wheels is selected as a selected wheel based on the acquired turning state amount, and the brake fluid supplied to the wheel braking device corresponding to the selected wheel A determination reference value of the braking operation amount used for the start determination of the pressure increase restriction control for changing the pressure below the hydraulic pressure in the corresponding hydraulic pressure pipe is determined based on the acquired turning state quantity, A pressure increase limiting control means for starting and executing the pressure increase limiting control in response to the detected braking operation amount exceeding the determination reference value;
A reference amount determination for determining a first auxiliary hydraulic pressure reference amount in the first hydraulic piping and a second auxiliary hydraulic pressure reference amount in the second hydraulic piping based on the detected braking operation amount. Means,
Based on the determined first and second auxiliary hydraulic pressure reference amounts and the acquired turning state amount, the first auxiliary hydraulic pressure target amount in the first hydraulic pipe is determined as the first auxiliary amount. A target amount determining means that determines a hydraulic pressure reference amount or more and determines a second auxiliary hydraulic pressure target amount in the second hydraulic pipe more than the second auxiliary hydraulic pressure reference amount;
Pressure adjusting means for adjusting the auxiliary hydraulic pressure in each of the first and second hydraulic pipes so as to coincide with the determined first and second auxiliary hydraulic pressure target amounts, respectively;
A vehicle braking control apparatus comprising: Four wheel braking devices that respectively apply braking torque corresponding to the braking hydraulic pressure supplied to the wheel cylinders of the four front, rear, left, and right wheels of the vehicle to the corresponding wheels;
A first hydraulic pressure generating device having two hydraulic pressure generating chambers each generating a hydraulic pressure amount corresponding to a braking operation amount by a driver of the vehicle;
A first hydraulically connecting one of the two hydraulic pressure generating chambers to two of the four wheel braking devices corresponding to the left and right front wheels or two corresponding to the left front wheel and the right rear wheel. Hydraulic piping,
A second hydraulically connecting the other of the two hydraulic pressure generating chambers to two of the four wheel braking devices corresponding to the left and right rear wheels or two corresponding to the right front wheel and the left rear wheel. Hydraulic piping of
A power-driven second hydraulic pressure generator for generating an auxiliary hydraulic pressure to be added to the hydraulic pressure amount generated by the first hydraulic pressure generator in each of the first and second hydraulic pressure pipes; ,
Braking operation amount detection means for detecting the braking operation amount;
Vehicle body deceleration detecting means for detecting the vehicle body deceleration of the vehicle;
State quantity acquisition means for acquiring a turning state quantity representing the turning motion of the vehicle;
In the turning state of the vehicle, at least one of the turning inner front and rear wheels is selected as a selected wheel based on the acquired turning state amount, and the braking fluid supplied to the wheel braking device corresponding to the selected wheel A determination reference value of the vehicle body deceleration used for the start determination of the pressure increase restriction control for changing the pressure below the hydraulic pressure in the corresponding hydraulic pressure pipe is determined based on the acquired turning state quantity, A pressure increase limiting control means for starting and executing the pressure increase limiting control in response to the detected vehicle body deceleration exceeding the determination reference value;
A reference amount determination for determining a first auxiliary hydraulic pressure reference amount in the first hydraulic piping and a second auxiliary hydraulic pressure reference amount in the second hydraulic piping based on the detected braking operation amount. Means,
Based on the determined first and second auxiliary hydraulic pressure reference amounts and the acquired turning state amount, the first auxiliary hydraulic pressure target amount in the first hydraulic pipe is determined as the first auxiliary amount. A target amount determining means that determines a hydraulic pressure reference amount or more and determines a second auxiliary hydraulic pressure target amount in the second hydraulic pipe more than the second auxiliary hydraulic pressure reference amount;
Pressure adjusting means for adjusting the auxiliary hydraulic pressure in each of the first and second hydraulic pipes so as to coincide with the determined first and second auxiliary hydraulic pressure target amounts, respectively;
A vehicle braking control apparatus comprising: Four wheel braking devices that respectively apply braking torque corresponding to the braking hydraulic pressure supplied to the wheel cylinders of the four front, rear, left, and right wheels of the vehicle to the corresponding wheels;
A first hydraulic pressure generating device having two hydraulic pressure generating chambers each generating a hydraulic pressure amount corresponding to a braking operation amount by a driver of the vehicle;
A first hydraulically connecting one of the two hydraulic pressure generating chambers to two of the four wheel braking devices corresponding to the left and right front wheels or two corresponding to the left front wheel and the right rear wheel. Hydraulic piping,
A second hydraulically connecting the other of the two hydraulic pressure generating chambers to two of the four wheel braking devices corresponding to the left and right rear wheels or two corresponding to the right front wheel and the left rear wheel. Hydraulic piping of
A power-driven second hydraulic pressure generator for generating an auxiliary hydraulic pressure to be added to the hydraulic pressure amount generated by the first hydraulic pressure generator in each of the first and second hydraulic pressure pipes; ,
Braking operation amount detection means for detecting the braking operation amount;
Braking fluid pressure acquisition means for detecting or estimating the braking fluid pressure supplied to the wheel cylinder of each wheel;
State quantity acquisition means for acquiring a turning state quantity representing the turning motion of the vehicle;
In the turning state of the vehicle, at least one of the turning inner front and rear wheels is selected as a selected wheel based on the acquired turning state amount, and the brake fluid supplied to the wheel braking device corresponding to the selected wheel Based on the acquired turning state amount, a determination reference value of the brake hydraulic pressure corresponding to the selected wheel used for the start determination of the pressure increase restriction control for causing the pressure to change below the hydraulic pressure in the corresponding hydraulic pressure pipe. A pressure increase limiting control means for starting and executing the pressure increase limiting control in response to the acquired braking hydraulic pressure corresponding to the selected wheel exceeding the determination reference value;
A reference amount determination for determining a first auxiliary hydraulic pressure reference amount in the first hydraulic piping and a second auxiliary hydraulic pressure reference amount in the second hydraulic piping based on the detected braking operation amount. Means,
Based on the determined first and second auxiliary hydraulic pressure reference amounts and the acquired turning state amount, the first auxiliary hydraulic pressure target amount in the first hydraulic pipe is determined as the first auxiliary amount. A target amount determining means that determines a hydraulic pressure reference amount or more and determines a second auxiliary hydraulic pressure target amount in the second hydraulic pipe more than the second auxiliary hydraulic pressure reference amount;
Pressure adjusting means for adjusting the auxiliary hydraulic pressure in each of the first and second hydraulic pipes so as to coincide with the determined first and second auxiliary hydraulic pressure target amounts, respectively;
A vehicle braking control apparatus comprising: Four wheel braking devices that respectively apply braking torque corresponding to the braking hydraulic pressure supplied to the wheel cylinders of the four front, rear, left, and right wheels of the vehicle to the corresponding wheels;
A first hydraulic pressure generating device having two hydraulic pressure generating chambers each generating a hydraulic pressure amount corresponding to a braking operation amount by a driver of the vehicle;
A first hydraulically connecting one of the two hydraulic pressure generating chambers to two of the four wheel braking devices corresponding to the left and right front wheels or two corresponding to the left front wheel and the right rear wheel. Hydraulic piping,
A second hydraulically connecting the other of the two hydraulic pressure generating chambers to two of the four wheel braking devices corresponding to the left and right rear wheels or two corresponding to the right front wheel and the left rear wheel. Hydraulic piping of
A power-driven second hydraulic pressure generator for generating an auxiliary hydraulic pressure to be added to the hydraulic pressure amount generated by the first hydraulic pressure generator in each of the first and second hydraulic pressure pipes; ,
Braking operation amount detection means for detecting the braking operation amount;
State quantity acquisition means for acquiring a turning state quantity representing the turning motion of the vehicle;
In the turning state of the vehicle, at least one of the turning inner front and rear wheels is selected as a selected wheel based on the acquired turning state amount, and the brake fluid supplied to the wheel braking device corresponding to the selected wheel A determination reference value of the turning state amount used for the start determination of the pressure increase restriction control for causing the pressure to change below the hydraulic pressure in the corresponding hydraulic pipe is determined, and the acquired turning state amount is the determination reference A pressure increase limiting control means for starting and executing the pressure increase limiting control in response to exceeding the value;
A reference amount determination for determining a first auxiliary hydraulic pressure reference amount in the first hydraulic piping and a second auxiliary hydraulic pressure reference amount in the second hydraulic piping based on the detected braking operation amount. Means,
Based on the determined first and second auxiliary hydraulic pressure reference amounts and the acquired turning state amount, the first auxiliary hydraulic pressure target amount in the first hydraulic pipe is determined as the first auxiliary amount. A target amount determining means that determines a hydraulic pressure reference amount or more and determines a second auxiliary hydraulic pressure target amount in the second hydraulic pipe more than the second auxiliary hydraulic pressure reference amount;
Pressure adjusting means for adjusting the auxiliary hydraulic pressure in each of the first and second hydraulic pipes so as to coincide with the determined first and second auxiliary hydraulic pressure target amounts, respectively;
A vehicle braking control apparatus comprising: Four wheel braking devices that respectively apply braking torque corresponding to the braking hydraulic pressure supplied to the wheel cylinders of the four front, rear, left, and right wheels of the vehicle to the corresponding wheels;
A first hydraulic pressure generating device having two hydraulic pressure generating chambers each generating a hydraulic pressure amount corresponding to a braking operation amount by a driver of the vehicle;
A first hydraulically connecting one of the two hydraulic pressure generating chambers to two of the four wheel braking devices corresponding to the left and right front wheels or two corresponding to the left front wheel and the right rear wheel. Hydraulic piping,
A second hydraulically connecting the other of the two hydraulic pressure generating chambers to two of the four wheel braking devices corresponding to the left and right rear wheels or two corresponding to the right front wheel and the left rear wheel. Hydraulic piping of
A power-driven second hydraulic pressure generator for generating an auxiliary hydraulic pressure to be added to the hydraulic pressure amount generated by the first hydraulic pressure generator in each of the first and second hydraulic pressure pipes; ,
Braking operation amount detection means for detecting the braking operation amount;
State quantity acquisition means for acquiring a wheel state quantity representing the slipperiness of the wheel;
While increasing at least one of the left and right rear wheels as a selected wheel and increasing the braking hydraulic pressure supplied to the wheel braking device corresponding to the selected wheel below the hydraulic pressure in the corresponding hydraulic piping A determination reference value of the wheel state quantity used for start determination of the restriction control is determined, and the pressure increase restriction control is started and executed in response to the acquired wheel state quantity exceeding the determination reference value. A pressure increase limiting control means,
A reference amount determination for determining a first auxiliary hydraulic pressure reference amount in the first hydraulic piping and a second auxiliary hydraulic pressure reference amount in the second hydraulic piping based on the detected braking operation amount. Means,
Based on the determined first and second auxiliary hydraulic pressure reference amounts and the obtained wheel state amount, the first auxiliary hydraulic pressure target amount in the first hydraulic pipe is determined as the first auxiliary amount. A target amount determining means that determines a hydraulic pressure reference amount or more and determines a second auxiliary hydraulic pressure target amount in the second hydraulic pipe more than the second auxiliary hydraulic pressure reference amount;
Pressure adjusting means for adjusting the auxiliary hydraulic pressure in each of the first and second hydraulic pipes so as to coincide with the determined first and second auxiliary hydraulic pressure target amounts, respectively;
A vehicle braking control apparatus comprising: The vehicle brake control device according to any one of claims 1 to 5,
The pressure increase restriction control means includes
A vehicle brake control device configured to determine the determination reference value based on a vehicle body speed of the vehicle. The vehicle brake control device according to any one of claims 1 to 4,
When the turning state amount at the start of braking acquired as the turning state amount at the start of the braking operation by the driver is less than or equal to a predetermined value,
The pressure increase restriction control means is configured not to perform the pressure increase restriction control, and the target amount determination means determines the first and second auxiliary hydraulic pressure target amounts as the first and second auxiliary liquids. A vehicle brake control device configured to maintain a value equal to the pressure reference amount.

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