JP4733453B2 - Brake hydraulic pressure control device for vehicles - Google Patents

Description

  The present invention relates to a vehicle brake fluid pressure control device, and more particularly to a vehicle brake fluid pressure control device that controls driving of a pump for supplying brake fluid pressure.

  2. Description of the Related Art Conventionally, vehicle brake hydraulic pressure control devices that perform antilock brake control, traction control, electronically controlled braking force distribution, and the like are known. These vehicle brake fluid pressure control devices supply the brake fluid pressure (auxiliary pressure) to the wheel cylinders by driving the pump. However, in recent years, due to the demand for a more comfortable driving environment, the drive noise of the pump (For example, refer to Patent Document 1 and Patent Document 2).

  In Patent Document 1, during traction control, noise is reduced by operating the pump drive motor at 40 to 60% of the nominal speed. Further, in Patent Document 2, when the electronically controlled braking force distribution is performed under a predetermined condition, that is, when the vehicle is not in a high-speed running state or a turning state and is not a low μ road, the start of the pump operation is delayed. By doing so, noise is reduced.

That is, in these conventional techniques, noise is reduced by slowing the drive of the pump or delaying the operation within a range where each function can be sufficiently and sufficiently exhibited.
Japanese translation of PCT publication No. 6-505939 (claim 1st claim, page 3, upper right column, 2nd to 3rd lines) JP 2001-39286 A (Claim 1, paragraph 0050, FIG. 6)

  By the way, in addition to anti-lock brake control and traction control, side slip suppression control that suppresses side slip and spin of the vehicle while turning and stabilizes the behavior of the vehicle is added, and vehicle behavior stabilization that comprehensively controls these Control is also known. In this vehicle behavior stabilization control, conventionally, when the deviation between the target hydraulic pressure and the estimated hydraulic pressure exceeds a threshold value, it is determined that rapid pressure increase is necessary, and the motor is driven with high output. However, in this determination method, a situation in which the deviation between the target hydraulic pressure and the estimated hydraulic pressure frequently exceeds a threshold value occurs frequently, so there are many opportunities to drive the motor at a high speed, and as a result, the noise caused by the driving is sufficient. Could not be reduced.

  Therefore, the present invention pays attention to the fact that the hydraulic pressure required for stabilization differs depending on the state of the turning motion when performing the vehicle behavior stabilization control, and sets and controls the drive condition of the pump according to the state of the turning motion. Thus, it is an object to reduce driving noise of the pump.

In order to solve the above-mentioned problem, the invention according to claim 1 of the present invention is unstable by the behavior determining means for determining whether or not the behavior of the turning vehicle corresponds to an unstable state, and the behavior determining means. And a pump drive control means for driving and controlling a pump for increasing the brake fluid pressure when determined to correspond to the state, the brake fluid pressure for the hydraulic brake of each wheel is stabilized so as to stabilize the behavior of the vehicle. A vehicle brake hydraulic pressure control device for controlling supply, comprising a turning state determining means for determining a state of a turning motion of the vehicle, wherein the pump drive control means is responsive to a determination result of the turning state determining means. The pump is driven and controlled with different outputs, and the turning state determination means has an oversteer state determination means for determining an oversteer state of the turning motion of the vehicle. The pump drive control means is configured to drive and control the pump at a lower output compared to a case where the oversteer state is not determined by the oversteer state determination means, compared to a case where the oversteer state is determined. The target hydraulic pressure setting means for setting the target hydraulic pressure of the brake hydraulic pressure in each wheel, and the deviation between the target hydraulic pressure set by the target pressure setting means and the actual hydraulic pressure of the brake hydraulic pressure in each wheel is calculated. A hydraulic pressure deviation calculating means for performing the operation when the pump drive control means determines that an oversteer state is detected and the maximum value among the deviations calculated by the hydraulic pressure deviation calculating means is greater than a predetermined value. maximum always the pump while being driven at 100% duty ratio so that the high output of the deviation calculated by said liquid pressure deviation calculating means If There smaller than a predetermined value, even during oversteer control, to drive control the pump at low output as compared to the case where and the maximum value when it is determined that the oversteer state is determined to be greater than the predetermined value It is characterized by.

According to such a brake fluid pressure control device for a vehicle, the drive state of the pump is optimized and the noise is reduced by controlling the drive of the pump with a different output (number of rotations) according to the determination result of the turning state determination means. can do.
Further, when it is not determined that the oversteer state is in the turning motion, the pump is driven and controlled at a lower output than when the oversteer state is determined. In other words, the oversteer state is a state in which the vehicle turns more than the rudder angle, and rapid pressure increase is required in preparation for the operation of the vehicle behavior stabilization control. On the other hand, since the boost request is not so high except in the oversteer state, noise can be reduced by lowering the pump drive.

Further, when the maximum value among the deviations calculated by the hydraulic pressure deviation calculating means is smaller than a predetermined value, the output is lower than when the state is opposed to the oversteer state and the maximum value is determined to be larger than the predetermined value. To control the drive of the pump. Thereby, even in the oversteer state, it is possible to suppress the driving of the pump according to the height of the boosting request and to reduce the noise.

Invention according to claim 2, calculates the vehicle brake hydraulic pressure control apparatus according to claim 1, and the actual turning amount detecting means for detecting an actual turning amount of the vehicle, the target turning amount of the vehicle target A turning amount calculating means; and a turning amount deviation calculating means for calculating a deviation between the detected actual turning amount and the calculated target turning amount; and the turning state determining means includes the calculated deviation. And the state of the turning motion can be determined based on whether or not the absolute value of the actual turning amount exceeds the absolute value of the target turning amount.

  According to such a brake fluid pressure control device for a vehicle, the vehicle turns based on the magnitude of the deviation between the actual turning amount and the target turning amount and whether the absolute value of the actual turning amount exceeds the absolute value of the target turning amount. Determine the state of exercise. Specifically, when the deviation satisfies a predetermined condition and the absolute value of the actual turning amount exceeds the absolute value of the target turning amount, it is determined that the vehicle is in an oversteer state. Thereby, the oversteer state can be accurately determined.

  ADVANTAGE OF THE INVENTION According to this invention, the drive noise of a pump at the time of performing vehicle behavior stabilization control can be reduced, and merchantability can be improved.

Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
In the drawings to be referred to, FIG. 1 is a configuration diagram of a vehicle including a vehicle brake hydraulic pressure control device according to the present embodiment, and FIG. 2 is a brake hydraulic pressure circuit diagram of the vehicle brake hydraulic pressure control device. .

  As shown in FIG. 1, the vehicle CR is equipped with the vehicle brake fluid pressure control device 10 according to the present embodiment, and the wheel speed of the wheel T connected to the vehicle brake fluid pressure control device 10 is mounted on the vehicle CR. The wheel speed sensor 31 for detecting the steering angle, the steering angle sensor 32 for detecting the steering angle of the steering ST, the lateral G sensor 33 for detecting the centrifugal force (acceleration) applied in the lateral direction of the vehicle CR, and the yaw rate when the vehicle CR is turning. A yaw rate sensor 34 (actual turning amount detecting means) for detecting, and a master pressure sensor 35 for detecting brake fluid pressure (hereinafter referred to as master cylinder pressure) generated in the master cylinder M (see FIG. 2) are provided. . One wheel speed sensor 31 is provided for each of the wheels T (T1, T2, T3, T4). Thus, in the vehicle brake hydraulic pressure control device 10, all four wheels T are provided. It is possible to obtain the wheel speed.

  The vehicle brake fluid pressure control device 10 is for appropriately controlling the braking force (brake fluid pressure) applied to each wheel T of the vehicle CR. As shown in FIG. 1, an oil passage and various parts are provided. The hydraulic unit 11 and the control device 12 for appropriately controlling various components in the hydraulic unit 11 are mainly provided. The brake hydraulic pressure output from the hydraulic pressure unit 11 is supplied to the wheel cylinders H provided on the wheels T via pipes, and is supplied to the wheels T via the wheel cylinders H. Brake hydraulic pressure is applied to the provided wheel brakes FL, FR, RL, RR.

  With reference to the brake hydraulic circuit diagram of FIG. 2, functions of various parts provided in the hydraulic unit 11 will be briefly described. In FIG. 2, a solid line connecting various components in the hydraulic unit 11 indicates a flow path (oil path) formed in the hydraulic unit 11.

  As shown in FIG. 2, the hydraulic pressure unit 11 is disposed between the master cylinder M that generates brake hydraulic pressure corresponding to the pedaling force applied by the driver to the brake pedal BP and the wheel brakes FL, FR, RL, RR. Has been. The two output ports M1, M2 of the master cylinder M are connected to the inlet port 12a of the hydraulic unit 11, and the outlet port 12b of the hydraulic unit 11 is connected to each wheel brake FL, FR, RL, RR. . In the normal state, the oil pressure path of the brake pedal BP is transmitted to the wheel brakes FL, FR, RL, and RR because the oil passage communicates from the inlet port 12a to the outlet port 12b in the hydraulic unit 11. It has become so.

  Here, the oil path starting from the output port M1 of the master cylinder M leads to the wheel brake FL on the left side of the front wheel and the wheel brake RR on the right side of the rear wheel, and the oil path starting from the output port M2 is set to the wheel brake FR on the right side of the front wheel. And the rear wheel brake RL on the left side. Hereinafter, the oil passage starting from the output port M1 is referred to as “first system”, and the oil passage starting from the output port M2 is referred to as “second system”.

  The hydraulic unit 11 is provided with two control valve means V corresponding to each wheel brake FL, RR in the first system, and similarly corresponding to each wheel brake RL, FR in the second system. Two control valve means V are provided. Further, the hydraulic unit 11 is provided with a reservoir 3, a pump 4, a damper 5, an orifice 5a, a regulator R, a suction valve 7, and a storage chamber 7a in each of the first system and the second system. A common electric motor 9 for driving the first system pump 4 and the second system pump 4 is provided. In the present embodiment, the master pressure sensor 35 that detects the master cylinder pressure described above is provided only in the second system.

  In the following, the oil passage from the output ports M1, M2 of the master cylinder M to each regulator R is referred to as “output hydraulic pressure passage A”, and the oil passage from the first system regulator R to the wheel brakes FL, RR and The oil passages from the second system regulator R to the wheel brakes RL and FR are respectively referred to as “wheel hydraulic pressure passage B”. In addition, an oil path from the output hydraulic pressure path A to the pump 4 is referred to as “suction hydraulic pressure path C”, an oil path from the pump 4 to the wheel hydraulic pressure path B is referred to as “discharge hydraulic pressure path D”, and The oil passage from the wheel fluid pressure passage B to the suction fluid pressure passage C is referred to as “open passage E”.

  The control valve means V opens the wheel hydraulic pressure path B while blocking the open path E, and the pressure reducing condition that blocks the wheel hydraulic pressure path B and opens the open path E, and blocks the wheel hydraulic pressure path B. However, it has a function of switching the holding state that shuts off the open path E, and includes an inlet valve 1, an outlet valve 2, and a check valve 1a.

  The inlet valve 1 is a normally open electromagnetic valve provided in the wheel hydraulic pressure path B. The inlet valve 1 is normally open, thereby allowing brake fluid pressure to be transmitted from the master cylinder M to the wheel brakes FL, FR, RL, RR. Further, the inlet valve 1 is closed by the control device 12 shown in FIG. 1 when the wheel is about to be locked, so that the brake hydraulic pressure transmitted from the brake pedal BP to the wheel brakes FL, FR, RL, RR. Shut off.

  The outlet valve 2 is a normally closed electromagnetic valve interposed between the wheel hydraulic pressure path B and the open path E. The outlet valve 2 is normally closed, but when the wheel is about to be locked, the outlet valve 2 is opened by the control device 12 shown in FIG. 1 so as to act on each wheel brake FL, FR, RL, RR. The hydraulic pressure is released to each reservoir 3.

  The check valve 1a is connected to each inlet valve 1 in parallel. This check valve 1a is a valve that only allows the brake fluid to flow from each wheel brake FL, FR, RL, RR side to the master cylinder M side, and when the input from the brake pedal BP is released, Even when the valve 1 is closed, the brake fluid is allowed to flow from each wheel brake FL, FR, RL, RR side to the master cylinder M side.

  The reservoir 3 is provided in the release path E and has a function of absorbing brake fluid pressure that is released when each outlet valve 2 is opened. Further, between the reservoir 3 and the pump 4, a check valve 3a that allows only the inflow of brake fluid from the reservoir 3 side to the pump 4 side is interposed.

  The pump 4 is interposed between the suction hydraulic pressure path C leading to the output hydraulic pressure path A and the discharge hydraulic pressure path D leading to the wheel hydraulic pressure path B, and sucks the brake fluid stored in the reservoir 3. And has a function of discharging to the discharge hydraulic pressure path D. As a result, the pressure state of the output hydraulic pressure path A and the wheel hydraulic pressure path B reduced by the absorption of the brake hydraulic pressure by the reservoir 3 is recovered. Further, in this pump 4, a cut valve 6 which will be described later blocks inflow of brake fluid from the output hydraulic pressure path A to the wheel hydraulic pressure path B, and a suction valve 7 which will be described later opens the suction hydraulic pressure path C. The brake fluid stored in the master cylinder M, the output hydraulic pressure path A, the suction hydraulic pressure path C, and the storage chamber 7a is sucked and discharged to the discharge hydraulic pressure path D. This makes it possible to apply brake fluid pressure to each wheel brake FL, FR, RL, RR during non-pedal operation.

  The damper 5 and the orifice 5a attenuate the pulsation of the pressure of the brake fluid discharged from the pump 4 and the pulsation generated by the operation of the regulator R described later by the cooperative action.

  The regulator R has a function of switching between a state where the brake fluid is allowed to flow from the output hydraulic pressure passage A to the wheel hydraulic pressure passage B and a state where the brake fluid is blocked, and a brake fluid flow from the output hydraulic pressure passage A to the wheel hydraulic pressure passage B. It has a function of adjusting the brake fluid pressure in the wheel fluid pressure passage B and the discharge fluid pressure passage D to a set value or less when the inflow is cut off, and the cut valve 6, the check valve 6a and the relief valve 6b are provided. It is prepared for.

  The cut valve 6 is a normally open electromagnetic valve interposed between the output hydraulic pressure path A leading to the master cylinder M and the wheel hydraulic pressure path B leading to each wheel brake FL, FR, RL, RR. The state in which the inflow of the brake fluid from the output hydraulic pressure path A to the wheel hydraulic pressure path B is permitted and the state in which the brake fluid is blocked are switched. The cut valve 6 is normally open, thereby allowing the brake fluid pressure to be transmitted from the master cylinder M to the wheel brakes FL, FR, RL, RR. Further, the cut valve 6 is a control device when the pump 4 is operated when the pedal is not operated, in other words, when the brake fluid pressure is applied to the wheel brakes FL, FR, RL, and RR when the pedal is not operated. It is blocked by 12 control.

  The check valve 6a is connected to each cut valve 6 in parallel. The check valve 6a is a valve that only allows the brake fluid to flow from the output hydraulic pressure path A to the wheel hydraulic pressure path B. When the cut valves 6 are closed, the check valve 6a receives an input from the brake pedal BP. Even if it exists, inflow of the brake fluid from the output hydraulic pressure path A to the wheel hydraulic pressure path B is permitted.

  The relief valve 6b is connected in parallel to each cut valve 6, and opens when the brake fluid pressure in the wheel fluid pressure passage B and the discharge fluid pressure passage D becomes equal to or higher than a set value. The cut valve 6 and the relief valve 6b can also be realized by a linear solenoid valve capable of adjusting the valve opening pressure by controlling energization to the solenoid, for example. If linear solenoid valves are employed as the cut valve 6 and the relief valve 6b in this way, the hydraulic pressure applied from the wheel hydraulic pressure path B to the regulator R, and the force for closing the valve controlled by energizing the solenoid, Therefore, the hydraulic pressure in the wheel hydraulic pressure passage B can be adjusted to be appropriately opened to the output hydraulic pressure passage A.

  The suction valve 7 is a normally closed electromagnetic valve provided in the suction fluid pressure passage C, and switches between a state in which the suction fluid pressure passage C is opened and a state in which the suction fluid pressure passage C is shut off. The suction valve 7 is in a non-pedal operation, and when the cut valve 6 is in a state of blocking the inflow of brake fluid from the output hydraulic pressure path A to the wheel hydraulic pressure path B, in other words, in the non-pedal operation. When the brake fluid pressure is applied to the wheel brakes FL, FR, RL, RR, it is opened (opened) by the control of the control device 12.

  The storage chamber 7 a is the suction fluid pressure path C and is provided between the pump 4 and the suction valve 7. The storage chamber 7a stores brake fluid, and the capacity of the brake fluid stored in the suction fluid pressure path C is thereby substantially increased.

  As shown in FIG. 1, the control device 12 includes a CPU, a RAM, a ROM, an input / output circuit, and the like, and includes a wheel speed sensor 31, a steering angle sensor 32, a lateral G sensor 33, a yaw rate sensor 34, and a master pressure sensor 35. Various arithmetic processes are performed based on the input from the computer and programs and data stored in the ROM, and control is executed.

FIG. 3 is a block diagram of the control device according to the present embodiment.
As shown in FIG. 3, the control device 12 controls the driving of the pump 4 and the electromagnetic valve in the hydraulic unit 11 based on the detection signals of the sensors 31 to 35 during the side slip suppression control during the turning of the vehicle CR. Is. The control device 12 includes a vehicle body speed estimation unit 121, a vehicle body behavior determination unit 122, a turning state determination unit 123, a target hydraulic pressure calculation unit 124, a brake hydraulic pressure estimation unit 125, a hydraulic pressure deviation calculation unit 126, The pump rotation number determination unit 127, the pump drive unit 128, and the valve drive unit 129 are included.

The vehicle body speed estimation unit 121 is based on the wheel speed V _W detected by the wheel speed sensor 31 (only one is shown in the figure) provided on each of the four wheels T and the actual yaw rate YR detected by the yaw rate sensor 34. V _V is calculated. Then, the vehicle body speed estimation unit 121 outputs the calculated vehicle body speed V _V to the vehicle body behavior determination unit 122. The vehicle body speed V _V can be calculated by a conventionally known method, and may be obtained from an average value of four wheel speeds V _W or may be obtained from an average value of driven wheels. Good.

The vehicle body behavior determination unit 122 receives the vehicle body speed V _V input from the vehicle body speed estimation unit 121, the steering angle θ from the steering angle sensor 32, the lateral acceleration G _Y from the lateral G sensor 33, and the actual yaw rate YR from the yaw rate sensor 34. Is detected, and it is determined whether or not the behavior of the vehicle satisfies a stability condition corresponding to the traveling state, and includes a target turning amount calculation unit 122A and a turning amount deviation calculation unit 122B. The target turning amount calculation unit 122A calculates a target yaw rate YR _NOM by performing a limit process using a lateral acceleration G _Y on a value obtained by searching a map (not shown) from the vehicle body speed V _V and the steering angle θ. Here, the target yaw rate YR _NOM is a yaw rate that should be in the neutral steering state. Further, the turning amount deviation calculation unit 122B calculates a yaw rate deviation ΔYR = YR _NOM −YR that is a difference between the actual yaw rate YR detected by the yaw rate sensor 34 and the target yaw rate YR _NOM . The yaw rate deviation ΔYR represents a “deviation” from the neutral steering state of the vehicle CR. Then, when the absolute value | ΔYR | of the yaw rate deviation ΔYR is equal to or greater than a predetermined value, the vehicle body behavior determination unit 122 determines that the vehicle state is unstable, and turns the turning state determination unit 123 and the target hydraulic pressure calculation unit 124. Output a signal. The target yaw rate corresponds to the target turning amount of [Claims], and the actual yaw rate corresponds to the actual turning amount of [Claims].

The turning state determination unit 123 determines whether the turning state of the vehicle is oversteer or understeer using the yaw rate deviation ΔYR calculated by the turning amount deviation calculation unit 122B. In the present embodiment, the oversteer determination unit 123A (In the figure, expressed as “OS determination unit”). The oversteer determination unit 123A determines whether the magnitude of the yaw rate deviation ΔYR and the absolute value | YR | of the actual yaw rate YR exceed the absolute value | YR _NOM | of the target yaw rate YR _NOM (| YR |> | YR _NOM |). Based on this, it is determined whether or not the turning state of the vehicle CR is oversteer. Here, a method for determining whether or not oversteering will be described with reference to FIG. FIG. 4 is a time chart showing an oversteer determination method at the time of vehicle turning, in which (a) is an actual yaw rate and a target yaw rate, (b) is a yaw rate deviation, (c) is an actual yaw rate code, and (d) is a yaw rate deviation. Reference numeral (e) indicates an oversteer determination result.

First, as necessary information, the yaw rate deviation ΔYR, the code of the actual yaw rate YR, and the yaw rate deviation ΔYR code are obtained.
As shown in FIG. 4A, when the vehicle CR starts turning in accordance with the driver's operation, the target yaw rate YR _NOM draws a waveform suitable for the steering. On the other hand, when the front or rear wheel T is not skidding, the actual yaw rate matches the target yaw rate YR _NOM. However, for example, when the front wheel is skidding, the absolute value of the actual yaw rate YR is the target yaw rate YR. _When the absolute value of the actual yaw rate YR is smaller than the absolute value of _NOM (for example, | YR | <| YR _NOM | between t1-t2, t3-t4, and t7-t8) and the rear wheel is skidding. It becomes larger than the absolute value of the target yaw rate YR _NOM (for example, | YR |> | YR _NOM | between t2-t3, t4-t5, t6-t7, and t8-t9).
When this is represented by the yaw rate deviation ΔYR calculated by the turning amount deviation calculation unit 122B, it is as shown in FIG. In this yaw rate deviation ΔYR, a threshold value L1 for oversteer determination is set. The change in the sign of the actual yaw rate YR shown in FIG. 4C indicates that the actual turning direction of the vehicle CR has changed. On the other hand, the yaw rate deviation code shown in FIG. 4D is switched every time the relationship between the magnitudes of the target yaw rate YR _NOM and the actual yaw rate YR is changed, that is, the sideslip rate of the front wheels and the sideslip rate of the rear wheels are changed. Each time the code is changed.

Then, as shown in FIG. 4 (e), the actual yaw rate code (FIG. 4 (c)) and the yaw rate deviation code (FIG. 4 (d)) are different signs, and the absolute value of the yaw rate deviation ΔYR is When the absolute value is equal to or greater than the absolute value of the threshold value L1 (| ΔYR | ≧ | L1 |), it is determined that oversteering occurs. In short, when the absolute value of the actual yaw rate YR is larger than the target yaw rate YR _NOM (| YR |> | YR _NOM |, see FIG. 4A), the absolute value of the yaw rate deviation ΔYR is equal to or larger than the absolute value of the threshold value L1. (| ΔYR | ≧ | L1 |) is determined to be oversteer.

As shown in FIG. 3, the target hydraulic pressure calculation unit 124 calculates the target hydraulic pressure _PT of each wheel brake FL, RL, FR, RR based on the yaw rate deviation ΔYR calculated by the vehicle body behavior determination unit 122. To do. The calculation method may be performed by a conventionally known method, and is not particularly limited. At this time, if the absolute value of the actual yaw rate YR is larger than the absolute value of the target yaw rate YR _NOM (| YR |> | YR _NOM |), a predetermined brake fluid is applied to the front outer wheel so as to decrease the actual yaw rate YR. Supply pressure. On the other hand, when the absolute value of the actual yaw rate YR is smaller than the absolute value of the target yaw rate YR _NOM (| YR | <| YR _NOM |), a predetermined brake fluid pressure is applied to the rear inner ring so as to increase the actual yaw rate YR. To supply.

The brake fluid pressure estimation unit 125 estimates the brake fluid pressure P _W in the wheel cylinder H based on the master cylinder pressure P _M detected from the master pressure sensor 35. This calculation method may be performed by a conventionally known method, and is not particularly limited. For example, the drive time of each inlet valve 1, outlet valve 2, cut valve 6, and suction valve 7 of the hydraulic unit 11 is acquired, and the number of revolutions of the motor 9 is detected to detect each inlet valve 1 and outlet valve 1. The time during which the valve 2 is opened and the amount of increase in the brake fluid pressure by driving the motor 9 are calculated. The brake fluid pressure P _W of each wheel can be estimated based on the release time, the pressure increase, and the master cylinder pressure P _M. The brake fluid pressure P _W in the wheel cylinder H may be detected by a pressure sensor.

The hydraulic pressure deviation calculation unit 126 calculates the target hydraulic pressure _PT output from the target hydraulic pressure calculation unit 124 and the hydraulic pressure deviation ΔP between the brake hydraulic pressure P _W of each wheel T output from the brake hydraulic pressure estimation unit 125. calculate. The hydraulic pressure deviation calculation unit 126 calculates the hydraulic pressure deviation ΔP for all four wheels T, and outputs the maximum hydraulic pressure deviation ΔP _MAX to the pump rotation speed determination unit 127.

The pump rotation speed determination unit 127 determines the rotation speed of the pump 4 from the signal input from the turning state determination unit 123 and the hydraulic pressure deviation ΔP _MAX input from the hydraulic pressure deviation calculation unit 126. The number of rotations of the pump 4 can be appropriately selected from three types of 0 rotation, low rotation, and high rotation.

  Here, the control flow of the hydraulic pressure deviation calculation unit 126 and the pump rotation speed determination unit 127 will be described with reference to FIGS. 5, 6, and 7. In the drawings to be referred to, FIG. 5 is a control flowchart of the hydraulic pressure deviation calculation unit and the pump rotation speed determination unit. FIG. 6 is a time chart for determining the target rotational speed during oversteering, where (a) is the brake fluid pressure estimated as the target fluid pressure, (b) is the fluid pressure deviation, and (c) is the oversteer. Determination, (d) shows the target rotational speed. FIG. 7 is a time chart for determining the target rotational speed at times other than oversteering, where (a) is the brake fluid pressure estimated as the target fluid pressure, (b) is the fluid pressure deviation, and (c) is the oversteer determination. , (D) shows the target rotational speed.

First, in the hydraulic pressure deviation calculation unit 126 (see FIG. 3), as shown in FIG. 5, whether or not the corresponding wheel T to be controlled is under vehicle behavior control, that is, the brake hydraulic pressure of the wheel T is increased or decreased. It is determined whether or not (step S1). If it is determined that the vehicle wheel T is under vehicle behavior control (Yes in step S1), the hydraulic pressure deviation ΔP (ΔP _MAX ) is saved (stored) in a RAM or the like which is not shown (step S2). ) It is determined whether or not the same processing has been completed for all four wheels T (step S3). If the four wheels have not been completed (No in step S3), the process returns to step S1 and the same process is repeated. In step S2, if the currently calculated hydraulic pressure deviation ΔP is smaller than the previous value, the previous value is saved as the maximum hydraulic pressure deviation ΔP _MAX , and if larger than the previous value, the current value is saved. Is saved as the maximum hydraulic pressure deviation ΔP _MAX . On the other hand, if the target wheel T is not being controlled by the vehicle behavior (No in step S1), the process proceeds to step S3, and the same processing as described above is performed.

When the process of the four-wheel component is determined to be finished (Yes in step S3), and whether it is oversteer (in oversteer control), and determines whether the liquid pressure deviation [Delta] P _MAX is the threshold value or more (step S4 ). If Yes in step S4, the pump rotation speed is set to “high rotation” (step S5), and the process ends. On the other hand, in the case of No in step S4, the pump rotation speed is set to “low rotation” (step S6), and the process ends.

That is, as shown in FIG. 6A, when the difference between the target hydraulic pressure P _T and the brake hydraulic pressure P _W is increased, and the hydraulic pressure deviation ΔP (FIG. 6B) is equal to or larger than a predetermined threshold L2. (T11-t12) and when the oversteer control mode (FIG. 6C) is under control (when oversteer is oversteered by the oversteer determination unit 123A), it is assumed that rapid boosting is required. (FIG. 6D) is set to “high rotation”. On the other hand, even when the oversteer control mode is under control (FIG. 6C), when the hydraulic pressure deviation ΔP (FIG. 6B) is less than the threshold (after t12), the pressure increase is not so rapid. As a thing, the target rotation speed (FIG. 6D) is set to “low rotation”. When the hydraulic pressure deviation ΔP is “0” (before t11 or after t13), the target rotational speed is also “0”. Incidentally, even if the hydraulic pressure deviation ΔP does not completely become “0”, it may be set so that the target rotation speed is set to “0” when it has a certain range and becomes equal to or less than a predetermined threshold value. .

  On the other hand, as shown in FIG. 7, when the oversteer control mode is not under control (FIG. 7C), the target rotational speed (FIG. 7D) is equal to the hydraulic pressure deviation ΔP (FIG. 7B). ) Is set to 'low rotation' regardless. When the hydraulic pressure deviation ΔP is “0” (before t14 or after t16), the target rotational speed is set to “0” as in the case where the oversteer control mode is being controlled.

As shown in FIG. 3, the pump drive unit 128 uses a conventionally known method so that the rotational speed of the pump 4 (see FIG. 2) matches the rotational speed determined by the pump rotational speed determination unit 127. A pulse signal for driving is output to the motor 9 of the hydraulic unit 11. Specifically, when the rotation speed of the pump 4 is determined to be “high rotation”, the duty ratio is set to, for example, 100% output by PWM control. On the other hand, when “low rotation” is determined, the duty ratio is set to 50%, for example. Thereby, according to this duty ratio, the rotation speed (output) of the motor 9 (see FIG. 2) of the hydraulic unit 11 changes, and the rotation speed (output) of the pump 4 also changes .

The valve drive unit 129 is conventionally known so that the brake hydraulic pressure P _W of the wheel cylinder H of each wheel brake FL, FR, RL, RR matches the target hydraulic pressure _PT calculated by the target hydraulic pressure calculation unit 124. A pulse signal for operating each inlet valve 1 and outlet valve 2, the cut valve 6, and the intake valve 7 in the hydraulic unit 11 is output to the hydraulic unit 11 by the method. For example, as the pulse signal ΔP between the brake hydraulic pressure P _W and the target hydraulic pressure P _T of the current wheel cylinder H increases, more pulses are output. The current brake fluid pressure of the wheel cylinder H may be measured by a sensor or estimated by calculation.

According to the above, the following effects can be obtained in the present embodiment.
According to the vehicle brake hydraulic pressure control device 10 according to the present embodiment, when the vehicle CR is in an oversteer state and the hydraulic pressure deviation ΔP _MAX is equal to or greater than the threshold value L2, the rotational speed of the pump 4 is increased ( High output), it is possible to accurately respond to a quick boost request. On the other hand, in cases other than the above, since the rotational speed of the pump 4 is lowered (low output), noise accompanying the driving of the pump 4 and the motor 9 can be reduced. Thereby, the merchantability of the vehicle CR can be improved.

As mentioned above, although embodiment of this invention was described, this invention is not limited to above-described embodiment, It can implement by changing suitably.
For example, in the present embodiment, the pump 4 is set to a low output except when “oversteered and the hydraulic pressure deviation ΔP _MAX is greater than or equal to the threshold L2”. However, the present invention is not limited to this. Alternatively, only the “when in the oversteer state” may be set to a high output, and otherwise it may be set to a low output.

It is a lineblock diagram of vehicles provided with a brake fluid pressure control device for vehicles concerning this embodiment. It is a brake fluid pressure circuit diagram of a brake fluid pressure control device for vehicles. It is a block block diagram of the control apparatus which concerns on this embodiment. It is a time chart which shows the oversteer judgment method at the time of vehicle turning, (a) is an actual yaw rate and a target yaw rate, (b) is a yaw rate deviation, (c) is an actual yaw rate code, (d) is a yaw rate deviation code, (e ) Indicates an oversteer determination result. It is a control flowchart of a hydraulic pressure deviation calculation part and a pump rotation speed determination part. It is a time chart at the time of determining the target number of rotations at the time of oversteering, (a) is brake fluid pressure estimated as target fluid pressure, (b) is fluid pressure deviation, (c) is oversteer judgment, (d) is Indicates the target speed. It is a time chart at the time of determining the target number of revolutions other than at the time of oversteering, (a) is brake fluid pressure estimated as target fluid pressure, (b) is fluid pressure deviation, (c) is oversteer judgment, (d) Indicates the target rotational speed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 4 Pump 10 Brake hydraulic control apparatus for vehicles 11 Hydraulic pressure unit 12 Control apparatus 121 Vehicle body speed estimation part 122 Car body behavior determination part 122A Target turning amount calculation part 122B Turning amount deviation calculation part 123 Turning state determination part 123A Oversteer determination part 124 Target Fluid pressure calculation unit 125 Brake fluid pressure estimation unit 126 Fluid pressure deviation calculation unit 127 Pump rotation speed determination unit 128 Pump drive unit CR vehicle T wheel

Claims (2)

Behavior determination means for determining whether or not the behavior of the vehicle during turning corresponds to an unstable state;
A pump drive control means for driving and controlling a pump for increasing the brake fluid pressure when it is determined by the behavior determination means to be in an unstable state;
A brake fluid pressure control device for a vehicle that controls supply of brake fluid pressure to a hydraulic brake of each wheel so as to stabilize the behavior of the vehicle,
A turning state determining means for determining the state of the turning motion of the vehicle;
The pump drive control means is configured to drive and control the pump with different outputs according to the determination result of the turning state determination means,
The turning state determination means includes oversteer state determination means for determining an oversteer state of the turning motion of the vehicle,
The pump drive control means is configured to drive and control the pump at a lower output than the oversteer state when the oversteer state determination means does not determine the oversteer state,
Furthermore, target hydraulic pressure setting means for setting a target hydraulic pressure of the brake hydraulic pressure in each wheel,
Hydraulic pressure deviation calculating means for calculating a deviation between the target hydraulic pressure set by the target pressure setting means and the actual hydraulic pressure of the brake hydraulic pressure in each wheel;
The pump drive control means has a duty ratio of 100 so that when the oversteer state is determined and the maximum value of the deviations calculated by the hydraulic pressure deviation calculation means is greater than a predetermined value, the pump has a high output. When the maximum value among the deviations calculated by the hydraulic pressure deviation calculating means is smaller than a predetermined value, even when oversteer control is being performed, if the oversteer state is determined and the maximum value is A vehicular brake hydraulic pressure control device that controls driving of the pump at a lower output than when determined to be larger than a predetermined value. An actual turning amount detecting means for detecting an actual turning amount of the vehicle;
A target turning amount calculating means for calculating a target turning amount of the vehicle;
A turning amount deviation calculating means for calculating a deviation between the detected actual turning amount and the calculated target turning amount;
The turning state determination means determines the state of the turning motion based on the calculated magnitude of deviation and whether or not the absolute value of the actual turning amount exceeds the absolute value of the target turning amount. The brake fluid pressure control device for a vehicle according to claim 1.

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