JP3223736B2 - Anti-skid control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle anti-skid control device.

[0002]

2. Description of the Related Art An anti-skid system (ABS) for controlling brake fluid pressure of a vehicle is effective in avoiding wheel lock during braking on a low μ road or the like.
As an actuator and control in such a system, an actuator having two solenoid valves per channel (so-called three-mode ABS in which each mode of pressure reduction, holding, and pressure increase is performed by a combination of valve opening and closing).
Is known. In addition, there is a type in which one 3-position valve is provided as one solenoid valve per channel. Although a number of ABS device configurations have been proposed as described above, with the spread of anti-skid devices, a more inexpensive system is desired.

[0003] Under such circumstances, the conventional anti-skid control device of the type having two two-position valves per channel (one per channel in the case of a three-position valve) requires one per channel. A type having two 2-position valves has also been proposed.

[0004]

However, in such a type, the hydraulic pressure cannot be maintained, and the pressure is constantly increased or decreased.
As shown in FIG. 8, since the actuator has non-linear characteristics, the brake fluid pressure is not maintained at a desired fluid pressure, and becomes lower than the target fluid pressure, or conversely becomes higher. There is a problem. Here, FIG. 18 shows that in the control of the brake fluid pressure (wheel cylinder (W / C) pressure) Pw / c, as shown in FIG. 18, even if the control amount corresponds to the same Δt period, the change amount is, for example, ΔP1, ΔP2, Δ
It is a consideration diagram (master cylinder pressure PM / C is constant) which is different from each other like P3 and ΔP4 and indicates that the actuator exhibits nonlinear characteristics.

[0005] On the other hand, in the ABS control, for example, with respect to a gradual change in the lock hydraulic pressure due to the movement of the load, it is an important element for improving controllability to gradually change and maintain the hydraulic pressure. However, in order to solve such a problem, Japanese Patent Application Laid-Open No. 62-64656 (Document 1) attempts to provide a hold mode by turning on / off a switch in hardware.

However, in such a conventional anti-skid control device, it is necessary to newly add a switch means as hardware, which leads to an increase in cost / size. If such an actuator having a complicated structure, resulting in an increase in size and causing an increase in cost is used for the corresponding channel, the cost and weight of the system mounted on the vehicle will increase accordingly. Furthermore, there is a problem in that necessary measures must be taken for fail-safe of a newly added part.

Therefore, as a solution to the above-described problem, the present applicant has previously proposed an improved anti-skid control device according to Japanese Patent Application No. 6-279242. According to this, anti-skid control can be realized in which the cost / size increase can be avoided and the holding mode can be effectively achieved even with one solenoid valve per channel.

According to the device according to the above proposal, in the case of an anti-skid device controlled by one solenoid valve per channel utilizing the slow pressure increase effect of the throttle, in response to a pressure increase / decrease command by the anti-skid control, the solenoid valve is controlled. Estimating the amount of pressure increase (or pressure reduction) at the time of pressure increase (or pressure reduction) in accordance with the off / on of the drive pulse of, and estimating the amount of pressure reduction (or pressure increase) at the time of subsequent pressure reduction (or pressure increase) By providing the drive pulse / duty ratio calculation means for calculating the duty ratio of the solenoid valve drive pulse while estimating the hydraulic pressure for each cycle, it is possible to control the hydraulic pressure to an arbitrary value while constantly estimating the hydraulic pressure. Therefore, the holding mode can be achieved without adding new hardware (hence, without increasing the size / cost). Therefore, it is possible to easily change and maintain the liquid pressure gently with respect to the gradual fluctuation of the lock liquid pressure due to the load movement, and there is no problem in the ABS control.

[0009] According to the above-mentioned proposal, the ABS control can be more effectively realized as compared with the conventional one. However, further improvements can be made in consideration of the following points. Have been found by the present inventor.

In the above-mentioned proposal, two methods, ie, a gradual increase and a sudden decrease
Since the anti-skid control device having only the mode is intended to be able to control to an arbitrary fluid pressure, etc., there is a method of controlling the W / C pressure by increasing the pressure and then reducing the pressure. It does not matter whether the system is used to control the W / C pressure by reducing the pressure and then increasing the pressure to increase the pressure. It is. Thus, for example,
In the case where the pressure is maintained, the pressure increase and the pressure reduction are only performed in combination. Actually, as shown in FIG. 15 or FIG. 16, even when the same target W / C pressure is controlled, the pressure is increased. Although there are two cases, that is, the case where the pressure is reduced after that and the case where the pressure is increased after the pressure is reduced, the order is not a problem.

FIG. 15 exemplarily shows a case where the current W / C pressure is controlled to the target W / C pressure in a manner of reducing the pressure after increasing the pressure. FIG. 3 exemplarily shows a case where the current W / C pressure is controlled to a target W / C pressure in a manner of increasing the pressure after reducing the pressure. Further, in the drawing, Pw / cM1 and Pw / cM2 function as estimated intermediate values (see below) applied when control is performed in the respective patterns.

By the way, as shown in FIG. 17, depending on the traveling conditions and road surface conditions, for example, if the control is performed in such a way that the pressure is always increased and then reduced, it is necessary to maintain the W / C pressure on a low μ road or the like. In some cases, the fluctuation range of the hydraulic pressure becomes large, the slip of the wheel gradually increases, and it may be difficult to secure a sufficient tire lateral force. The figure shows the wheel speed Vw, the pseudo vehicle body speed Vi, and the wheel cylinder pressure P under ABS control.
w / c, which indicates the transition and change of the solenoid valve drive pulse (solenoid valve drive pulse) Isol, respectively.
In the case of the control by the thick line waveform portion of the drive pulse Isol waveform in the lower part of the figure, the wheel cylinder pressure P
The control of w / c changes in a state like a bold line, while
The thick line portion (hatched portion) for the wheel speed Vw is
This represents a decline in wheel speed. Conversely, when the control is performed in such a manner that the pressure is always increased after the pressure is reduced, the fluctuation range of the hydraulic pressure becomes large, which may affect the behavior of the wheels.
FIG. 16 shows an example in which the pattern in which the pressure is reduced after the pressure increase has a larger variation in hydraulic pressure than the pattern in which the pressure is increased after the pressure reduction.

[0013] Therefore, in view of these aspects, the control according to the above proposal has room for improvement.

The present invention realizes a further improved anti-skid control which can further improve the control based on the above considerations and can make the control appropriate in terms of hydraulic pressure fluctuation. It is to try.

[0015]

According to the present invention, the following anti-skid control device is provided. That is, an anti-skid device that outputs a drive pulse to an electromagnetic valve disposed for each wheel to perform pressure reduction and gentle pressure increase control of wheel cylinder pressure,
In response to the pressure increase / decrease command by the anti-skid control, by estimating the pressure increase amount at the time of pressure increase and estimating the pressure decrease amount at the time of subsequent pressure decrease, the hydraulic pressure is output to the solenoid valve while estimating the fluid pressure for each cycle. A first drive pulse / duty calculating means for calculating the duty of the first drive pulse; and estimating the amount of pressure reduction at the time of pressure reduction and estimating the amount of pressure increase at the time of pressure increase in response to a pressure increase / decrease command by anti-skid control. By doing so, the second drive pulse / duty calculation means for calculating the duty of the second drive pulse output to the solenoid valve while estimating the hydraulic pressure for each cycle, and the pulse / duty calculation by these drive pulse / duty calculation means An anti-slip device comprising: a selection unit that selects one of a first drive pulse and a second drive pulse in accordance with a hydraulic pressure fluctuation width when the duty is controlled. A head controller.

Here, the selecting means determines the larger one of the current wheel cylinder pressure and the difference between the target wheel cylinder pressure and the temporary wheel cylinder pressure generated by the drive pulse for increasing / decreasing the hydraulic pressure. It is characterized by comparing the fluctuation range of the hydraulic pressure between the case where the pressure is reduced after the pressure is increased and the case where the pressure is increased after the pressure is reduced, and selecting the generation mode of the drive pulse so as to be small.

Further, the electromagnetic valve is a two-position valve, and the anti-skid control device is characterized in that, when the electromagnetic valve is in anti-skid control, the brake fluid of the wheel cylinder is drained at the valve opening position, In the closed position, the solenoid valve is driven and controlled by a supplied pulse signal so as to block the drainage of the brake fluid, and the path from the master cylinder to the wheel cylinder includes a difference between the upstream side and the downstream side. An anti-skid control device, which is a valve driven by pressure, and which has a valve for slowly increasing pressure in anti-skid control by a throttle.

[0018]

According to the above-described structure, the advantages of the anti-skid control device according to the above proposal can be secured, cost / size can be avoided, and the holding mode can be effectively achieved even with one solenoid valve per channel. Anti-skid control can be realized, and two operations of the first drive pulse / duty operation means and the second drive pulse / duty operation means as the drive pulse / duty operation means of the solenoid valve are performed. Means and means for selecting the drive pulse output, while making it possible to control the fluid pressure to an arbitrary fluid pressure while constantly estimating the fluid pressure, and to cause unnecessary behavior of the wheels due to a large fluid pressure fluctuation. It is also possible to prevent unnecessary sinking of the wheel speed, thereby making it possible to realize finer control. Also, depending on the adjustment of the pulse output cycle, etc.,
More linear hydraulic pressure control can be performed, and more advanced control can be realized in an inexpensive system with one solenoid valve per channel.

Further, the selecting means determines the larger of the current wheel cylinder pressure and the difference between the target wheel cylinder pressure and the temporary wheel cylinder pressure generated by the drive pulse for increasing or decreasing the pressure. Since the range of fluctuation is compared with the range of hydraulic pressure fluctuation between the case where pressure is reduced after pressure increase and the case where pressure is increased after pressure reduction, it is configured as means for selecting the generation mode of the drive pulse so as to be small. In the case of the configuration, it is appropriately achieved that the method of controlling the hydraulic pressure is selected so that the fluctuation range of the hydraulic pressure becomes smaller, and the duty is selected so as to obtain the optimum amount of pressure increase and decrease. And become more effective.

In addition, the anti-skid control device of the present invention can be implemented as a configuration in which the electromagnetic valve is a two-position valve, and similarly, the above can be realized. In addition, a solenoid that is driven and controlled by a pulse signal supplied so that the electromagnetic valve drains brake fluid from the wheel cylinder at the valve open position during anti-skid control and shuts off the brake fluid at the valve closed position. A valve, a route from the master cylinder to the wheel cylinder includes:
The anti-skid control device according to the present invention can be implemented as a valve that is driven by a differential pressure between the upstream side and the downstream side, and has a valve that slowly increases pressure in anti-skid control by a throttle. It is possible to realize. Preferably, a wheel speed calculating means for calculating a wheel speed from an output from a wheel speed sensor, a vehicle speed estimating means for estimating a vehicle speed from the wheel speed, and a wheel acceleration calculating means for calculating a wheel acceleration from the wheel speed The present invention can be implemented by including means for calculating the amount of pressure increase / decrease from the wheel speed, wheel acceleration, and the estimated vehicle speed, and drive pulse output means for outputting a drive pulse.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of one embodiment of the present invention.
In this embodiment, the vehicle to be applied is a four-channel anti-skid system (4ch ABS) that can independently control the left and right brake fluid pressures (brake fluid pressure) for both front and rear wheels.

In the drawing, 1 is a brake pedal, 2 is a booster as a brake booster, 3 is a reservoir, 4 is a master cylinder (M / C), and 10 and 2 respectively.
0 indicates left and right front wheels of the vehicle, and 30 and 40 indicate left and right rear wheels, respectively. Each wheel 10, 20, 30, 40 includes a wheel cylinder (W / C) 11, 21, 31, 41, and an actuator for avoiding wheel lock is provided between the master cylinder 4 and the wheel cylinder. Provided.

In the illustrated example, channels for each wheel are provided with inlet valves 12, 22, 32, 42 and outlet valves 13, 23, 33, 43, and reservoirs 8, 9 and a pump 6 driven by a motor 5 are provided. , 7 as elements, and an anti-skid device for piping and connecting them to form an ABS hydraulic circuit as shown in the figure. From the master cylinder 4 to the wheel cylinders 11 to 4
1, in the front-wheel (front) brake system, the master cylinder fluid path connects this to the inlet valves 12 and 22 individually, and the fluid path on each wheel cylinder side is connected from the inlet valves 12 and 22. To the wheel cylinders 11 and 21 of the front wheels 10 and 20 respectively. Similarly, for the rear wheel (rear) brake system, the master cylinder fluid path is connected to the inlet valves 32 and 4.
2 are connected individually, and the rear wheels 30, 40 are connected from the inlet valves 32, 42 through the liquid passages on the respective wheel cylinder sides.
Of each wheel cylinder 31, 41.

Each of the wheel cylinder fluid passages connected to each of the front wheel wheel cylinders 11 and 21 branches in the middle thereof, and these branch fluid passages are connected to the front wheel reservoir 8 via outlet valves 13 and 23, respectively. Through the master pump 6 to the master cylinder fluid path on the upstream side. Similarly, the wheel cylinder fluid passages connected to the wheel cylinders 31 and 41 of the rear wheels also branch from the middle, respectively, and these branch fluid passages are connected to the outlet valves 33 and 43.
Through the rear wheel pump 7 and to the master cylinder fluid path on the upstream side.

Each of the inlet valves 12, 22, 32, 4
Here, reference numeral 2 denotes an inlet valve which is driven by a differential pressure between the upstream side (master cylinder side) and the downstream side (each wheel cylinder side), and creates a gradual pressure increase by a throttle. In addition, each of the outlet valves 13, 23, 33, 43 is a two-position solenoid valve for ON / OFF control here. One such outlet valve is provided for each channel and is normally (in a state where the solenoid is not energized) at the first position shown in the drawing and is connected between the valve input / output ports, and accordingly, the corresponding reservoirs 8, 9 And a two-port two-position solenoid valve that takes a second position to connect the input and output ports when switching, and thus a position to connect the wheel cylinders to the corresponding reservoirs 8, 9. This is used to reduce the wheel cylinder pressure by conducting the brake fluid of the corresponding wheel cylinder to the reservoir during anti-skid control. In the control of this embodiment, the inlet valves (mechanical) 12, 22, 3
2 and 42 are master cylinder 4 and wheel cylinder 1
By performing a duty control (described later) as drive control for the outlet valves 13, 23, 33, and 43, the wheel cylinders 11 of the corresponding wheels are respectively inserted in the corresponding channels. , 21, 31, and 41, the brake fluid pressure (brake fluid pressure P) is individually controlled.

In the case of the illustrated example, the inlet valves 12, 2
Reference numerals 2, 32, and 42 assume positions where the throttle is not actuated in a state where no differential pressure is generated between the upstream side and the downstream side. In addition, the outlet valves 13, 23, 33, 43 maintain the illustrated closed position when OFF. In such a state, when the hydraulic pressure from the master cylinder 4 is supplied to each wheel cylinder by depressing the brake pedal 1, the master cylinder pressure is transmitted as it is through the master cylinder liquid path, each inlet valve, and the wheel cylinder liquid path. So,
The brake fluid pressure can be increased to the master cylinder fluid pressure, which is the original pressure, and each wheel is individually braked to perform normal braking.

At the time of such braking, when the outlet valves 13, 23, 33, 43 of the respective channels are operated so as to open and close, the branch fluid paths to the corresponding reservoirs 8, 9 are opened at the valve opening positions. The brake fluid of the corresponding wheel cylinder is guided to the reservoir and drained. Also,
During the period in which the valve is in the closed position, the communication with the reservoir is cut off to cut off the brake fluid pressure. Thus, by such opening / closing drive control of the outlet valve, a reduced pressure state is established in which the brake fluid pressure is released to the corresponding reservoir and reduced.

The brake fluid accumulated in the reservoirs 8 and 9 due to the reduced pressure is supplied to pumps 6 and 7 driven by the motor 5.
With this, it is returned upstream of the inlet valves 12, 22, 32, 42. Then, the returned brake fluid is used for pressure increase. Outlet valve 13,23,3
When the pressure in the corresponding fluid passage on the wheel cylinder side becomes lower than the fluid passage on the master cylinder side due to the pressure reduction due to the operation of 3, 43, the inlet valves 12, 22, 32, 42 operate due to the differential pressure generated between the upstream side and the downstream side. Thus, the communication between the master cylinder 4 and the corresponding wheel cylinder is switched to a communication with a throttle, and the wheel cylinder pressure is gradually increased.

Each of the outlet valves 13, 23, 33, 43 of the anti-skid device and the pump driving motor 5
Is controlled by an output signal of the controller 50. The controller 50 has wheel speed sensors 51, 52, 53, 54 for detecting wheel speeds, which are disposed on the respective wheels 10, 20, 30, 40.
Input signals from The controller 5
0, in the present embodiment, the brake switch (SW) 55
Is also input.

The controller 50 includes an input detection circuit, an arithmetic processing circuit, a storage program for storing a control program such as anti-skid control executed by the arithmetic processing circuit, a calculation result, etc., and outlet valves 13 and 23. ,
33, 43 and an output circuit for supplying a control signal to the motor 5.

In this embodiment, the gradual pressure-increasing effect of the throttles at the inlet valves 12, 22, 32, 42 for each channel, which is a mechanical valve mechanism driven by a differential pressure, is used. This is an anti-skid device in which the hydraulic pressure of the wheel to be controlled is controlled by outlet valves 13, 23, 33, and 43, which are one electromagnetic valve per channel. When braking, the controller 50 controls the wheel based on input information. The anti-skid control is executed by controlling the drive of the outlet valves 13, 23, 33, 43 in order to prevent the brake lock of the above. In the case of the ABS control of the four-channel four-sensor system as in this example, basically, when the wheel speed information is obtained for each of the four front, rear, left and right wheels, the vehicle speed is estimated from the wheel speed, and the wheel acceleration is used. If so, calculate the wheel acceleration from the wheel speed for each wheel,
By obtaining a target pressure increase / decrease amount from the wheel speed, the wheel acceleration, and the vehicle body speed and controlling the wheel cylinder hydraulic pressure of the corresponding wheel, it is possible to perform control to avoid wheel lock during braking.

Further, as described above, the controller 50 is configured to use one outlet valve 13, 23, 33, 43 of one 2-position valve per channel.
Even if the ABS has only the slow pressure increase mode and the pressure reduction mode and controls the solenoid valve based on the pulse signal, it also achieves the pressure reduction and pressure increase as well as the holding mode that holds the brake fluid pressure at the desired pressure In the arithmetic processing circuit, the outlet valves 13, 23, 3
The processing for calculating the duty of the drive pulse for the third and the fourth 43 is also executed, and the drive control of those is performed.

Furthermore, in this case, the controller 50
Is to be able to estimate the fluid pressure and control it to any fluid pressure,
When the duty of the drive pulse is calculated while estimating the hydraulic pressure, it also has the following function in addition to this.

That is, the calculated pulse duty when controlling the hydraulic pressure in a pattern of increasing the pressure and then reducing the pressure, and the calculated pulse / duty when controlling the hydraulic pressure in a pattern of reducing the pressure and then increasing the pressure. In the case of the duty, the case where the case where the hydraulic pressure fluctuation width becomes smaller is selected and determined, and the outlet valves 13, 23, and 23 as the electromagnetic valves are determined according to the drive pulse generation method thus selected. Control for performing drive control on 33 and 43 is also performed.

FIG. 2 is a block diagram showing an example of the outline of the function of the embodiment system shown in FIG. 1 for such ABS control. As shown
Wheel speed calculating means a for calculating a wheel speed from an output from a wheel speed sensor provided for each wheel to be controlled, vehicle speed estimating means b for estimating a vehicle speed from the wheel speed, and wheel acceleration calculating for calculating a wheel acceleration from the wheel speed Means c, a pressure-increase / decrease amount calculating means d for calculating a pressure-increase / decrease amount from the estimated vehicle speed and the wheel speed, and a drive pulse output means f for outputting a drive pulse.
, A second drive pulse / duty calculator k, and a drive pulse / duty selector m.

First drive pulse / duty operation means h
In response to the pressure increase / decrease command by the anti-skid control, the pressure increase amount at the time of pressure increase according to the OFF / ON of the solenoid valve drive pulse and the pressure decrease amount at the time of the subsequent pressure decrease are estimated. The second drive pulse / duty calculation means k calculates the duty of the solenoid valve drive pulse while estimating the hydraulic pressure of the solenoid valve. The duty of the solenoid valve drive pulse is calculated while estimating the hydraulic pressure in each cycle by estimating the amount of pressure reduction during pressure reduction according to the ON / OFF of the pulse and estimating the amount of pressure increase during subsequent pressure increase. Drive pulse / duty calculating means,
The drive pulse / duty selection means m is configured to increase or decrease the output method of the solenoid valve drive pulse after the pressure is increased or decreased, depending on the fluid pressure fluctuation width when the control is performed with both the pulse duties. This is a selection unit that functions as a drive pulse generation method selection unit that selects whether to reduce the pressure.

Here, the parts of the wheel speed calculating means a, the vehicle speed estimating means b, the wheel acceleration calculating means c, the pressure increasing / decreasing amount calculating means d, and the driving pulse output means f are provided by a known normal anti-skid control. In contrast to the anti-skid control system, the anti-skid control device according to the present invention further includes first and second drive pulse / duty operation means h and k and drive pulse / duty selection means. m is provided,
In addition, the anti-skid actuator g of the 1ch1 electromagnetic valve is combined. The first and second drive pulse / duty operation means h and k are configured to include a pressure increase estimator and a pressure decrease estimator, respectively. The drive pulse output means f is obtained by the drive pulse / duty operation means. And outputs a drive pulse according to any one of the pulse duties selected by the drive pulse duty selection means m to the anti-skid actuator g, and outputs a braking fluid pressure P,
Therefore, the wheel cylinder pressure is controlled.

Preferably, the driving pulse / duty selecting means m as the driving pulse generating method selecting means includes ABS
During control execution, the current wheel cylinder pressure (W / C pressure),
The larger of the difference between the target wheel cylinder pressure (W / C pressure) and the temporary wheel cylinder pressure (W / C pressure) generated by the drive pulse for increasing / decreasing the pressure was set as the hydraulic pressure fluctuation range, and the pressure was increased. The method of generating a drive pulse is selected so as to reduce the fluctuation range of the hydraulic pressure when the pressure is reduced later and when the pressure is increased after the pressure is reduced.

In the present embodiment, the wheel speed calculating means a, the vehicle speed estimating means b, the wheel acceleration calculating means c, and the pressure increasing / decreasing amount calculating means d are one of the wheel speed sensors 51 to 54 and the controller 50 shown in FIG. It is comprised including a part. The controller 50 also comprises drive pulse / duty calculation means h and k, drive pulse / duty selection means m and drive pulse output means f, and the anti-skid actuator g further comprises outlet valves 13 and 23 as solenoid valves. , 33, and 34, between the master cylinder 4 and the wheel cylinders 11, 21, 31, and 41 by the ABS hydraulic circuit shown in FIG.

FIGS. 3 to 6, 9 and 10 show the anti-skid control including the above-described first and second drive pulse duty calculation processing and drive pulse duty selection processing executed by the controller 50. It is a flowchart of an example of a program. This process is performed by a periodic interrupt at a fixed time interval by an operating system (not shown). 7 and 8, and FIG.
12 is a characteristic diagram showing an example of an actuator model used for estimating the pressure increase amount and the pressure decrease amount, respectively, and the characteristic data can be stored in the storage circuit of the controller 50 in advance. 13 and FIG.
FIG. 4 is a diagram provided for explaining the control contents.

Hereinafter, description will be made with reference to these figures.
The control programs shown in FIGS. 3 and 4 include reading the wheel speed, calculating the wheel acceleration, calculating the pseudo vehicle speed, calculating the target pressure increase / decrease amount, the solenoid valve / drive pulse / first duty calculation routine, the solenoid valve / drive pulse / Second Duty Calculation Routine, Drive Pulse / Duty Selection, and Drive Pulse Output Processes (Steps S100 to S10
7).

In FIG. 3, first, in step S100, each wheel speed Vwi (i = 1 to 4) is read based on signals from the wheel speed sensors 51 to 54. Next, in step S101, a wheel acceleration Vwd is calculated from the wheel speed Vwi. In the present embodiment, for example, it is determined from the speed difference between 30 msec.

In the following step S102, the pseudo vehicle speed V
Calculate i. In the present embodiment, Vi is calculated by a method used in normal ABS. That is, here
A filter is applied to the wheel speed Vw of each wheel, and a value Vwfi (i = 1 to 4) closer to the vehicle speed is calculated for each wheel.
Depending on conditions such as when braking is not performed, Vwf (referred to as the vehicle speed intermediate value) closest to the vehicle speed is calculated by selecting the largest one from each Vwfi, and the pseudo vehicle speed Vi is further determined based on this Vwf. I will ask.

Next, in step S103, for each wheel,
The target pressure increase / decrease amount ΔP ^* is calculated. In the present embodiment, the anti-skid control is, for example, PD control. Briefly, a target pressure increase / decrease amount ΔP ^* is calculated from the wheel speed Vw, the pseudo vehicle body speed Vi, and the wheel acceleration Vwd of each wheel obtained in steps S100 to S103 according to the following equation 1.

ΔP ^* = kp × (Vw ^* −Vw) + kd × (Vwd ^* −Vwd) 1

Here, kp and kd are control gains (proportional control gain and differential control gain), respectively, and are changed according to the running state. Vw ^* is a target value of the wheel speed, and is obtained by, for example, Vw ^* = Vi × α (α is a target slip ratio). Vwd ^* is a target value of the wheel acceleration, and is obtained, for example, as Vwd ^* = 1.2 g + β (β is changed by the road surface μ judgment).

Then, as described above, the target pressure increase / decrease amount ΔP ^*
Is calculated, the calculated value ΔP ^* is used here (FIG. 6).
In step S209 and step S309 in FIG. 10), in each of subsequent steps S104 and S105, a solenoid valve is provided for driving pulse output processing to the solenoid valves provided in each channel as the outlet valves 13 to 43 (step S107). In addition to calculating the drive pulse duty, one of those calculated in step S106 is selected and determined, and based on this, a drive pulse is output each time step S107 is executed, thereby performing the outlet valve duty control. .

In step S104 (FIG. 4), the solenoid valve driving pulse when the fluid pressure is controlled in a pattern of first increasing pressure and then decreasing pressure (of course, in the case of full pressure reduction (see below), only pressure reduction is performed)・ Calculate the duty. FIGS. 5 and 6 show an example of such a solenoid valve drive pulse / first duty calculation routine.

In FIG. 5, first, a master cylinder pressure is estimated in step S200. In the present embodiment, the M / C pressure is raised at a certain slope by the on signal of the brake SW 55, for example, the maximum M / C pressure is set to 16 MPa,
/ C pressure. Here, in order to further improve the accuracy, the M / C pressure may be corrected according to the deceleration during the ABS operation. Next, in step S201, the W / C pressure (Pw / ci) is estimated. In the present embodiment, it is assumed that the W / C pressure is estimated from the previous pulse duty calculated by the method described later (see the next step and subsequent steps).

Then, in step S202 and thereafter, the solenoid valve drive pulse duty is calculated. More specifically, first, an initial value of the pulse duty DT is set in step S202. In this program example, DT
= 0. Note that DT represents a time during which the outlet valve is closed during a pulse output period T, for example, T = 50 msec, and is defined as, for example, DT = 10 msec. Therefore, in this case, when the initial value is set, that is, when DT = 0, the full pressure reduction (the open position is taken during the entire period of T = 50 msec). Also, DT ≠
When it is 0, for example, in the case of DT = 10 msec, this means that during the period T = 50 msec, the outlet valve is in the closed position for 10 msec, and is in the open position for 40 msec.

Next, in step S203, the value DT is set to 0.
It is determined whether or not. Here, when DT = 0, since the pressure is full as described above, the process proceeds to step S204, and the pressure increase amount is set to zero, that is, ΔPinc = 0. Then, the process proceeds to step S206. On the other hand, if DT ≠ 0, pressure increase is also performed, so the process proceeds to step S205, and the pressure increase amount is estimated.

The contents of this processing are as follows. That is,
In step S205, the pressure increase amount ΔPinc is calculated from the M / C pressure, the current W / C pressure, and the duty DT using, for example, an actuator model (characteristic) as shown in FIG. The value ΔPinc is applied to the calculation in the next step S206 and a later-described step S209. In this example, for example, based on the characteristic when DT = 5 msec, the actuator model (characteristic) is determined. Holding
The pressure increase amount ΔPinc at the time of DT = 5 msec is calculated from the M / C pressure and the current W / C pressure, for example, DT = 10 msec.
In this case, the model is simplified by, for example, doubling it.

Next, at step S206, the W / C pressure Pw
/ Ci and the pressure increase amount ΔPi estimated in step S205
nc, the W / C pressure Pw / ciM (referred to as an estimated intermediate value) after pressure increase is estimated (for example, the estimated intermediate value Pw in FIG. 14).
/ CiM1). That is,

## EQU00002 ## The W / C pressure after the pressure increase is calculated from the W / C pressure after the pressure increase Pw / ciM = Pw / ci + .DELTA.Pinc ... 2.

Next, in step S207, the decompression time DTD is calculated by subtracting the duty DT from the pulse output period T from the following equation (3).

DTD = T−DT 3

Then, in step S208, the pressure reduction amount is estimated. In the present embodiment, the estimated intermediate value Pw / ciM estimated in step S206 and the decompression time D obtained above are calculated using, for example, an actuator model (characteristic) as shown in FIG.
The pressure reduction amount ΔPdec is calculated from TD. Calculated value ΔPde
c together with the pressure increase amount ΔPinc in the next step S
209 is applied to the calculation. Here, as shown in FIG. 8, the pressure reduction side is the same as the pressure increase side (step S205, FIG. 7), for example, based on the characteristics when the pressure reduction time DTD = 5 msec. For example, when DTD = 10 msec, it is doubled. In this way, the model is simplified.

When the estimated pressure increase amount and the estimated pressure decrease amount are obtained as described above, it is determined whether or not the current duty DT is appropriate in the next step S209 and thereafter (FIG. 6). First, in step S209, step S1 is performed.
03 and the target pressure increase amount [Delta] P ^* calculated in (3), the estimated increase respectively determined in step S205, S208 pressure amount Δ
ΔPn which is the difference between the total change amount between Pinc and the estimated pressure reduction amount ΔPdec (that is, ΔPinc−ΔPdec)
To

４Pn = ΔP ^* − (ΔPinc−ΔPdec) 4

Next, at step S210, the difference value Δ
The sign of Pn is determined. As a result of this determination, ΔPn ≦ 0
Is not satisfied, that is, if ΔPn is positive, it means that the current duty DT has not increased or decreased to the target amount of increase or decrease in pressure (there is a large amount of decrease in pressure).
The program proceeds to step 11 to check whether DT <T. As a result, if DT <T, that is, if the pressure-increasing time has not reached the pulse output period T and the pressure-increasing amount can still be increased, the process proceeds to step S212, where the duty is incremented and the step S203 is performed. Returning to the upstream of (FIG. 5), the duty after the increment is applied, and the estimation is performed again according to the above-described processing. In this case, steps S203 → S205 → S206
The process of → S207 → S208 → S209 is repeated, and in that process, the determination in step S210 and, if applicable, further in step S211 are performed.

Here, at step S212, 1
Is incremented (DT = DT + 1), but if the basis of the actuator model (characteristic) applied in step S205 is DT = 5 msec (FIG. 7), the increment is set to 5 in this increment processing (this Regarding the point, a later-described step S21
The same applies to the case of the decrement processing in No. 4).

Thus, if DT <T, DT is incremented. If DT = T, DT cannot be increased any more, so DT = T (full pressure increase, ie, DTD = 0)
Is determined. In the case where the present calculation routine is ended in this way, when the drive pulse output process according to the process is executed in step S107 (FIG. 4), the cycle T = 5.
The outlet valve will be in the closed position over the entire period of 0 msec.

When the difference value ΔPn is calculated in step S209 and the process proceeds to step S210, the difference
When Pn is negative or zero, it can be determined that the target increase / decrease amount can be sufficiently achieved with the current duty, so that the process proceeds to step S213 and thereafter, and this calculation routine ends.

In this program example, the previous ΔPn−1
Value (the target pressure increase / decrease amount ΔP ^* and the estimated pressure increase amount ΔPi obtained above)
nc and the total change amount between the estimated pressure reduction amount ΔPdec) and the current ΔPn (current value), and the smaller one is selected. That is, in step S213, | ΔPn |
If ≧ | ΔPn−1 |, the value DT is decremented in step S214 so as to select the previous duty. In this way, the previous duty is selected as the difference value according to the above equation 4 with respect to the target amount ΔP ^* required for the anti-skid control (step S103) so that | ΔPn | ≧ | ΔPn-1 | The target amount ΔP ^*
This is because it can be controlled to a value close to. Therefore, when the duty DT is set in this manner, since the decrement process is performed, the pulse duty DT corresponding to the immediately preceding duty is determined according to the selection in step S106.
When applied to the process of step S107 (FIG. 4), as a result, a drive pulse is output in accordance therewith and duty control is performed, and hydraulic pressure control in accordance with the target amount ΔP ^* is performed in anti-skid control. Will be

Conversely, in the case of | ΔPn | <| ΔPn−1 | (this means that, contrary to the above, the difference value calculated by the equation 4 is smaller in the current calculation value) Is
Since the pulse duty DT can be controlled to a value closer to the target amount ΔP ^* by performing the duty control with the current duty than by setting the pulse duty DT to a value equivalent to the previous previous duty, it is necessary to select the current duty. This routine ends without performing the decrement of step S214, and proceeds to step S105 (FIG. 4). Here, also in this case, the pulse duty DT that can be controlled to a value closer to the target is set as described above, and this is determined by the selection in step S106 (FIG. 4).
If applied to the processing of step 107, as a result, appropriate outlet valve duty control will be executed,
In the anti-skid control, it is possible to perform the hydraulic control in accordance with the target amount ΔP ^* .

As described above, in the above-described solenoid valve drive pulse / first duty calculation routine, the drive pulse / duty is calculated when the hydraulic pressure is controlled by reducing the pressure after increasing the pressure. The pulse duty is calculated so as to obtain an appropriate pressure increase / decrease amount.

FIG. 13 shows an example in which outlet valve duty control is performed with the pulse duty calculated in the first duty calculation routine. To explain, the current W / C pressure is now Pw / c.
o, and the current time is to. When DT = 0 (n = 0 at this time), the pressure is reduced until time t + T during the period T. In this case, the difference ΔPn between the target pressure increase / decrease amount ΔP ^* and the total change amount between the estimated pressure increase amount ΔPinc and the estimated pressure decrease amount ΔPdec is ΔPo = ΔP ^* + ΔPdec (o). Since ΔPo> 0 and DT <T, (FIG. 6, Step S
210, 211), DT is incremented (step S212), and estimation is performed again. Repeat this,
For example, when DT = n-1, first, the pressure increase amount ΔPinc
(N-1) is estimated, an estimated intermediate value Pw / cMn-1 is calculated, and [Delta] Pn-1 is obtained. At this time, the estimated final W / C pressure is set to Pw / cn-1. At this time, ΔPn
Since DT> T when -1> 0, the estimation is performed again. Similarly, when DT = n, Pw / cMn and ΔPn are obtained. At this time, ΔPn ≧ 0 for the first time, and as described above, in the next step (step S213), DT = n
| ΔPn | in case of | and | ΔPn- in case of DT = n-1
By comparing the magnitudes of 1 |, it is determined which one can be selected to control the value closer to the target. In the case of the example of FIG. 13, as shown in the figure, since | ΔPn | ≦ | ΔPn−1 |
= N is selected. In this case, the outlet valve duty control is executed according to the selection as described above.

Referring back to FIG. 4, in step S105 following step S104, the hydraulic pressure is controlled in a pattern of firstly reducing the pressure and then increasing the pressure (of course, when the pressure is full, only the pressure is increased). Calculate the solenoid valve drive pulse duty. The solenoid valve drive pulse
FIGS. 9 and 10 (steps S300 to S314) show an example of the second duty calculation routine.

The basic concept of this routine is the same as that of the arithmetic processing shown in FIGS. 5 and 6, and as can be understood from comparison with FIGS.
The only difference is that the estimation order of pressure increase and decrease is reversed. Therefore, the contents of the description of the drive pulse / duty calculation process (solenoid valve drive pulse / first duty calculation routine) described with reference to FIGS. 5, 6, 7 and 8 and FIG. By estimating the pressure reduction amount ΔPdec at the time of pressure reduction and estimating the pressure increase amount ΔPinc at the time of pressure increase according to the processes and procedures shown in FIGS.
This is applicable to the case of this routine in which the duty of the drive pulse of the outlet valve is calculated while estimating the hydraulic pressure in each cycle T, and the description can be replaced with the corresponding description, and the details thereof will be repeated. Although the description is omitted, the correspondence and the like are shown as follows.

Steps S300 and S301 in FIG. 9 and step S302 in which the pulse duty initial value DTD (decompression time) = 0 are performed in step S20, respectively.
0, S201, and S203, a step S303 of determining whether DTD = 0, a step S304 of ΔPdec = 0, and a step S3 of estimating the pressure reduction amount ΔPdec.
05 is performed in steps S203 and S20, respectively.
4, corresponding to the procedure of S205. Here, step S3
The actuator model (characteristic) used in FIG. 11 is the same as FIG. 8 (the horizontal axis parameter data is Pw / c) according to FIG.
Apply i). W / C pressure Pw / ciM =
Pw / ci-ΔPdec calculation step S306, DT
= T-DTD calculation step S307 and pressure increase amount ΔP
The process of step S308 for inc estimation corresponds to the procedure of steps S206, S207, and S208, respectively. Here, the value calculated in step S306 is the W / C pressure Pw / ciM after pressure reduction (estimated intermediate value, for example, FIG.
(See the estimated intermediate value Pw / ciM2), and the actuator model (characteristic) used in step S308.
Also, FIG. 12 (horizontal axis parameter data is Pw / ciM (W / C pressure estimated intermediate value after decompression)) according to FIG. 7 is applied.

Further, in step S309 of FIG. 10, ΔPn
The processing of step S310 for determining whether ≧ 0, the step S311 for determining whether DTD <T, and the step S312 of the increment processing are performed in step S20, respectively.
9, S210, S211 and S212, and the processing of the determination step S313 and the step S314 of the decrement processing are performed in steps S213 and S213, respectively.
214.

Also in the case of the solenoid valve drive pulse / second duty calculation routine in steps S300 to S314, similarly to the case of the solenoid valve drive pulse / first duty calculation routine, there can be used a control which can be controlled to a value close to the target. The pulse duty calculation is performed so as to be calculated. Thus, in the selection process of step S106 (FIG. 4), whether the fact that which of the pressure increase after pressure reduction or decompression after pressure increase is chosen, both, in case so by the target pressure increase amount [Delta] P ^* The duty is calculated so that the increase / decrease amount is obtained.

Referring back to FIG. 4, after each of the above-described calculation routines (steps S104 and S105), the flow advances to the next step S106 to determine which of the pulse duty calculated above is to be selected. The content of the processing here is, depending on the hydraulic pressure fluctuation width when controlled with both the pulse duties described above, the method of outputting the drive pulse to the outlet valve, a method of increasing the pressure after reducing or increasing the pressure It is a matter of deciding whether to adopt a method of reducing pressure later.

In the present embodiment, specifically, as shown in FIG. 14, the current W / C pressure Pw / ci and the target W
/ C pressure value “Pw / ci + ΔP ^* ” and a temporary W / C pressure Pw / ciM generated by a drive pulse for increasing / decreasing pressure
(Estimated intermediate value) (Pw / c shown in FIG. 14)
i−Pw / ciM | and | (Pw / ci + ΔP ^* ) − Pw
/ CiM |) is taken as the hydraulic pressure fluctuation range, and the driving pulse generation is performed so that the fluctuation range is reduced by comparing the hydraulic pressure fluctuation widths when the pressure is increased and then reduced and then increased. Choose a method. In the example of FIG. 14, | Pw / ci−Pw / ciM1 | is a description of the current W / C pressure in the pattern (FIGS. 15 and 16) in which the pressure is reduced after the pressure increase and the calculation routine of step S104. Difference from estimated intermediate value Pw / ciM1, | Pw / ci + ΔP ^* −P
w / ciM1 | (... [2]) is the estimated intermediate value Pw /
It is the difference between ciM1 and the target W / C pressure, and | Pw /
ci-Pw / ciM2 | (... [1]) is the current W / in the pattern (FIGS. 15 and 16) in which the pressure is increased after the pressure is reduced.
The difference between the C pressure and the estimated intermediate value Pw / ciM2 mentioned in the calculation routine of step S105, | Pw / ci + ΔP ^*
-Pw / ciM2 | is a difference between the estimated intermediate value Pw / ciM2 and the target W / C pressure. In the illustrated example, in the case of a pattern in which the pressure is increased after the pressure is reduced, | Pw / ci in [1] of FIG.
-Pw / ciM2 | is defined as a hydraulic pressure fluctuation width (comparison hydraulic pressure fluctuation width), and in the case of a pattern in which pressure is reduced after pressure increase, | Pw / ci + ΔP ^* -Pw / ciM1 |
Is the hydraulic pressure fluctuation width (comparable hydraulic pressure fluctuation width),
These [1] and [2] are compared.

In other words, in this case, the maximum width of the change in hydraulic pressure that can occur is | P
w / ci + ΔP ^* −Pw / ciM | is the fluctuation range of the hydraulic pressure, and | Pw / ci−Pw
/ CiM | is the range of fluctuation of the hydraulic pressure.

In the case of | Pw / ci−Pw / ciM |> | Pw / ci + ΔP ^* −Pw / ciM |, a pattern in which the pressure is reduced after the pressure is increased (that is, a pattern in which the fluctuation range of the hydraulic pressure becomes smaller) is used. Select,

In the case of | Pw / ci−Pw / ciM | ≦ | Pw / ci + ΔP ^* −Pw / ciM |, a pattern in which the pressure is increased after the pressure is reduced (that is, a pattern in which the fluctuation range of the hydraulic pressure becomes smaller) is selected. Things.
In the present example, the processing of step S106 can be realized by utilizing the calculated values handled in the processing of steps S104 and S105.

Then, after the processing of step S106, the process proceeds to the output processing of step S107, and the driving pulse according to the above selection is output. As described above, the method of controlling the hydraulic pressure is selected so that the fluctuation range of the hydraulic pressure becomes smaller, and the duty is selected so as to obtain the optimal pressure increase / decrease amount. It will be executed according to.

According to the control of the present embodiment, since the hydraulic pressure control can be performed as described above, similar to the case of the previously proposed anti-skid control device by the present applicant, wheel lock avoidance is avoided. In the case of realizing brake hydraulic pressure control, it is possible to improve the device configuration and control, and it is also possible to realize ABS control by making this more appropriate in terms of hydraulic pressure fluctuation. In this control, basically, it is possible to control to an arbitrary hydraulic pressure while always estimating the hydraulic pressure, while being in the two modes of the gradual pressure increasing mode and the pressure decreasing mode,
Therefore, in maintaining the hydraulic pressure, even if a switch means such as the conventional one is not added, the size / cost is not increased, and one outlet valve as a solenoid valve is sufficient for one channel. Thus, a holding mode in which holding can be performed at an arbitrary hydraulic pressure can be achieved. Therefore, even if a gradual change or holding of the hydraulic pressure is required even with a gradual change of the lock hydraulic pressure due to the load movement, the lock hydraulic pressure can be easily responded to. With the duty control of the drive pulse for one solenoid valve per channel, so-called three-mode ABS control including the holding mode is also possible, and effective ABS control is realized.

Further, in the present embodiment, in addition to the above, in the anti-skid device controlled by one solenoid valve per channel utilizing the slow pressure increasing effect of such a throttle, first consider FIGS. In addition, regarding the drive pulse duty calculation, on the other hand, with respect to the target pressure increase / decrease amount ΔP ^* which is the pressure increase / decrease command by the anti-skid control, the turning off / on of the outlet valve drive pulse is performed. Estimation of the pressure increase amount ΔPinc at the time of pressure increase according to the ON state and the pressure decrease amount ΔPde at the time of subsequent pressure decrease
By performing the estimation of c, the calculation is performed while estimating the hydraulic pressure for each cycle T (step S104).
On the other hand, in response to the pressure increase / decrease command by the anti-skid control, the pressure reduction amount ΔPdec at the time of pressure reduction according to the ON / OFF of the outlet valve drive pulse and the pressure increase amount ΔPinc at the time of subsequent pressure increase are estimated. While performing the calculation while estimating the hydraulic pressure for each cycle T (step S1).
05), after reducing the output method of the outlet valve drive pulse according to the range of hydraulic pressure fluctuation that would occur when controlling with both pulse duties obtained by such calculation. An appropriate selection can be made as to whether to increase the pressure or to decrease the pressure after the increase (Step S10).
6).

In this way, it is possible to control the hydraulic pressure to an arbitrary pressure while always estimating the hydraulic pressure. Therefore, it is possible to maintain the hydraulic pressure in the above-described two-mode control at an arbitrary hydraulic pressure, and to achieve a smooth ABS control. Of course, in this case, it is also possible to selectively switch between controlling by a pattern of increasing pressure after increasing pressure or controlling by increasing the pressure after decreasing pressure, to the more advantageous one in terms of the fluid pressure fluctuation range. Thus, the occurrence of unnecessary behavior of the wheels due to an increase in hydraulic pressure fluctuation can be further reduced. Then, it is possible to prevent unnecessary sinking of the wheel speed as shown in FIG. 17, for example. FIG.
The transition of the thin line portion of the wheel speed Vw indicates a more desirable state without such sinking, and the W / C pressure Pw /
c, the corresponding thin line portion of the drive pulse Isol (upper stage) corresponds to this. In the driving pulse output waveform in the upper part of the figure, it can be seen that the pulse output method has changed before and after the point in the middle of the hydraulic pressure holding mode.

Further, depending on the adjustment of the pulse output period T and the like, more linear hydraulic pressure control can be performed, and more sophisticated control can be performed in an inexpensive anti-skid system having one solenoid valve per channel.

In the case of the configuration of Document 1 described above, it is necessary to add a new switch means as hardware, which leads to an increase in cost / size and a fail-safe operation for the newly added portion. However, in the case of the present embodiment, it is needless to say that there is no need to take a fail-safe countermeasure due to the addition of such a switch means as in the case of the previous proposal. .

The present invention is not limited to the above embodiments and the like. For example, in the above, 4 channels AB
Although S is taken as an example, it goes without saying that the present invention can be similarly applied to three-channel ABS. Also, for example, AB with an inlet valve and an outlet valve
A preferred example of the S actuator is shown in FIG.
It is not limited to the illustrated one.

[0079]

According to the present invention, when the brake fluid pressure control for avoiding the wheel lock is realized, the apparatus configuration and the control are further improved, and the cost / size increase can be avoided. With one solenoid valve, anti-skid control that can also effectively achieve the holding mode can be realized, and the first drive pulse / duty calculation means and the second drive pulse / duty calculation means as the solenoid valve drive pulse / duty calculation means Two driving pulse / duty calculating means and two driving pulse / duty calculating means, and selecting means for selecting the first driving pulse and the second driving pulse, so that the liquid pressure can be controlled to an arbitrary value while always estimating the liquid pressure. In addition, the occurrence of unnecessary behavior of the wheels due to large fluctuations in the hydraulic pressure is reduced, and unnecessary sinking of the wheel speed can be prevented. Is possible to realize fine control of, it is possible to realize a more improved anti-skid control.
Further, by adjusting the pulse output cycle and the like, more linear hydraulic pressure control can be performed, and more advanced control can be realized in an inexpensive system with one solenoid valve per channel.

Further, the selecting means determines the larger one of the current wheel cylinder pressure and the difference between the target wheel cylinder pressure and the temporary wheel cylinder pressure generated by the drive pulse for increasing / decreasing the hydraulic pressure. Since the range of fluctuation is compared with the range of hydraulic pressure fluctuation between the case where pressure is reduced after pressure increase and the case where pressure is increased after pressure reduction, it is configured as means for selecting the generation mode of the drive pulse so as to be small. In the case of the configuration, it is appropriately achieved that the method of controlling the hydraulic pressure is selected so that the fluctuation range of the hydraulic pressure becomes smaller, and the duty is selected so as to obtain the optimum amount of pressure increase and decrease. And make it more effective.

Further, the present invention can be implemented as a configuration in which the electromagnetic valve is a two-position valve, and the above can be similarly realized. In addition, a solenoid that is driven and controlled by a pulse signal supplied so that the electromagnetic valve drains brake fluid from the wheel cylinder at the valve open position during anti-skid control and shuts off the brake fluid at the valve closed position. A valve that is a valve that is driven by a differential pressure between the upstream side and the downstream side, and that has a valve that slowly increases pressure in anti-skid control by a throttle in a path from the master cylinder to the wheel cylinder. The present invention can be implemented, and the same can be realized similarly. Preferably, a wheel speed calculating means for calculating a wheel speed from an output from a wheel speed sensor, a vehicle speed estimating means for estimating a vehicle speed from the wheel speed, and a wheel acceleration calculating means for calculating a wheel acceleration from the wheel speed The present invention can be implemented by including means for calculating the amount of pressure increase / decrease from the wheel speed, wheel acceleration, and the estimated vehicle speed, and drive pulse output means for outputting a drive pulse. In this case as well, the above can be realized similarly.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a functional block diagram illustrating an example of a basic configuration of control contents in the same example.

FIG. 3 is a flowchart showing a part of an example of a control program executed by the controller of the example.

FIG. 4 is a flowchart showing another part.

FIG. 5 shows an example of a solenoid / valve drive pulse / first duty calculation routine in the same program.
It is a flowchart which shows a part.

FIG. 6 is a flowchart showing another part.

FIG. 7 is a view showing an example of an actuator model used for estimating a pressure increase amount applicable to the routine.

FIG. 8 is a diagram showing an example of an actuator model used for estimating a reduced pressure amount, which is applicable to the same routine.

FIG. 9 shows an example of a solenoid / valve drive pulse / second duty calculation routine in the same program.
It is a flowchart which shows a part.

FIG. 10 is a flowchart showing another part.

FIG. 11 is a diagram showing an example of an actuator model used for estimating a reduced pressure amount, which can be applied to the same routine.

FIG. 12 is a diagram showing an example of an actuator model used for estimating a pressure increase amount applicable to the routine.

FIG. 13 is a diagram provided for explanation of control contents.

FIG. 14 is also a diagram for explaining the contents of control, and is a diagram showing an example of selection of a driving pulse generation method according to a hydraulic pressure fluctuation width.

FIG. 15 is a consideration diagram for describing two patterns in a case where control is performed to a target hydraulic pressure.

FIG. 16 is a consideration diagram showing an example of drive pulses corresponding to two patterns of hydraulic pressure control and the state of hydraulic pressure fluctuation in each case.

FIG. 17 is a timing chart illustrating the state of the ABS control.

FIG. 18 is a diagram illustrating that an actuator exhibits nonlinear characteristics.

[Explanation of symbols]

Reference Signs List 1 brake pedal 2 booster 3 reservoir 4 master cylinder 5 motor 6,7 pump 8,9 reservoir 10,20 left and right front wheels 11,21,31,41 wheel cylinder 12,22,32,42 inlet valves (mechanical) 13,23 , 33, 43 Outlet valves (electromagnetic valves) 30, 40 Left and right rear wheels 50 Controller 51, 52, 53, 54 Wheel speed sensor 55 Brake switch (SW)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-175355 (JP, A) JP-A-62-295761 (JP, A) JP-A-5-246317 (JP, A) JP-A-1- 131902 (JP, A) JP-A-8-133301 (JP, A) JP-A-8-133050 (JP, A) JP-A-8-34329 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60T 8/58 B60T 8/36

Claims (3)

(57) [Claims] 1. An anti-skid device that outputs a drive pulse to an electromagnetic valve disposed for each wheel to perform pressure reduction and gradual pressure increase control of a wheel cylinder pressure. estimation and subsequent decompression when the pressure reduction amount of the estimation of the pressure increase amount by performing a first for computing the duty of the first drive pulse to be output to the solenoid valve while estimating the fluid pressure in each cycle a drive pulse duty arithmetic means, to decrease pressure command by the anti-skid control, by performing estimation of pressure increase amount estimation and subsequent pressure increase in the pressure reduction amount of vacuum at the time, the hydraulic pressure for each cycle pulse by the second second driving pulse duty arithmetic means, these driving pulse duty arithmetic means for calculating the duty of the drive pulses to be output to the solenoid valve while estimating the
Depending on the hydraulic pressure change width in the case of control by duty, first
Selection means for selecting either one of the drive pulse and the second drive pulse of the current wheel cylinder.
Pressure, and target wheel cylinder pressure and pressure increase / decrease drive
Temporary wheel cylinder pressure difference caused by pulse
The larger of the two is used as the fluid pressure fluctuation range.
Pressure fluctuation range between when the pressure is increased and after the pressure is reduced
Compare the drive pulse generation state
An anti-skid control device, comprising: a selection unit for selecting a mode . Wherein said solenoid valve is a two position valve, the anti-skid control apparatus according to claim 1 Symbol mounting, characterized in that. 3. The method according to claim 2, wherein the solenoid valve is configured to perform anti-skid control.
A solenoid valve that is driven and controlled by a pulse signal supplied so as to drain the brake fluid from the wheel cylinder at the valve open position and shut off the brake fluid at the valve closed position. the path leading to a valve that is driven by a differential pressure between the upstream side and the downstream side, according to claim 1 or claim, having a valve for gradual pressure increase in the anti-skid control by the diaphragm, it is characterized by 2 Symbol mounting of anti-skid control apparatus.