JPH05112113A - Electric control device for suspension device - Google Patents

Abstract

PURPOSE:To get accurate suspension characteristics during braking period by controlling the suspension characteristics so as to be shifted to a harder side as the estimated braking oil pressure to wheel cylinders becomes high according to the state of non-operation or operation of an anti-lock control device when a brake pedal is pressed down. CONSTITUTION:When a brake pedal 12 is pressed down and an anti-lock control device 15 is not operated, a brake micro-computer 16 calculates the deceleration from the signals of rotational speed sensors 17a to 17d of wheels W1 to W4, and estimates the first estimated braking oil pressure on the basis of the calculated deceleration, and controls the braking oil pressure to wheel cylinders 13a to 13d. Furthermore, a suspension micro-computer 24 receives the first braking oil pressure, and estimates the second estimated braking oil pressure on the basis of the braking oil pressure changing control time, and controls the suspension characteristics of shock absorbers 21a to 21d. Consequently, it is possible to estimate the braking oil pressure accurately and to control the suspension characteristics.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle suspension system, and more particularly to an electric control system for a suspension system which controls the suspension characteristics of the suspension system during braking to prevent the vehicle body from nose diving.

[0002]

2. Description of the Related Art Conventionally, an apparatus of this type has been disclosed in, for example, Japanese Patent Laid-Open No.
As disclosed in Japanese Patent Laid-Open No.-212215, a hydraulic pressure is generated according to the amount of depression of the brake pedal, and the generated hydraulic pressure is supplied to the shock absorber so that as the amount of depression of the brake pedal increases. The damping force is controlled to be large.
As a result, as the amount of depression of the brake pedal increases, the suspension characteristic of the suspension device is set to the hard side, and the nose dive of the vehicle body during braking of the vehicle can be prevented.

[0003]

However, when the above-mentioned conventional device is applied to a vehicle equipped with an anti-lock control device, when the wheels are likely to lock, the anti-lock control device operates and the wheel cylinder is locked. The lock of the wheel is avoided by increasing / decreasing the brake hydraulic pressure supplied to the wheel. Therefore, in this type of vehicle, the brake hydraulic pressure supplied to the wheel cylinders changes independently of the amount of depression of the brake pedal when the anti-lock control device is activated, so the suspension characteristics during braking of the vehicle can be accurately determined. Cannot control.

The present invention has been made to solve the above problems, and its purpose is to accurately estimate the brake hydraulic pressure supplied to the wheel cylinders even if the antilock control device is activated, and An object of the present invention is to provide an electric control device for a suspension device that accurately controls the suspension characteristics during braking.

[0005]

In order to achieve the above object, the structural feature of the present invention is that a brake that applies a brake oil pressure corresponding to the depression amount of a brake pedal to a wheel cylinder to apply a braking force to the wheel. A hydraulic device and an anti-lock control device that operates when the wheels are likely to lock due to the application of the braking force and increases / decreases the brake hydraulic pressure supplied to the wheel cylinders to avoid locking the wheels. An electric control device for a suspension device for controlling suspension characteristics of a suspension device, a deceleration detecting means for detecting a wheel deceleration, and an anti-lock control at the time of depressing a brake pedal. Based on the detected deceleration when the device is inactive, the wheel cylinder is supplied with And a first brake oil pressure estimating means for estimating the brake oil pressure, and the brake oil pressure increasing / decreasing control time by the antilock control means when the antilock control device is in an operating state when the brake pedal is depressed. Second brake oil pressure estimating means for estimating the brake oil pressure supplied to the wheel cylinder,
Suspension characteristic control means for controlling the suspension device according to the estimated brake hydraulic pressure by the first and second brake hydraulic pressure estimation means and controlling the suspension characteristic of the suspension device to the hard side as the estimated brake hydraulic pressure increases. It consists of.

[0006]

In the present invention constructed as described above, when the brake pedal is depressed, the first brake oil pressure estimating means is detected by the deceleration detecting means if the antilock control device is in the inoperative state. The brake hydraulic pressure applied to the wheel cylinders is estimated based on the deceleration.
In this case, since the wheels are not locked, the brake hydraulic pressure supplied to the wheel cylinders and the deceleration of the wheels are in a proportional relationship, and the estimated brake hydraulic pressure is accurate. When the antilock control device is in the operating state, the second brake hydraulic pressure estimating means estimates the brake hydraulic pressure based on the increase / decrease control time of the brake hydraulic pressure by the antilock control means. In this case, the anti-lock control means controls the brake hydraulic pressure supplied to the wheel cylinders to increase or decrease, that is, the brake hydraulic pressure is increased or decreased, and the brake hydraulic pressure is applied to these pressure increase control time and pressure decrease control time. Therefore, in this case as well,
The estimated brake hydraulic pressure is accurate.
Then, the suspension characteristic control means controls the suspension device based on the estimated brake hydraulic pressure,
Since the suspension characteristic of the suspension device is controlled to the hard side as the brake hydraulic pressure increases, the suspension characteristic is controlled to the hard side as the brake hydraulic pressure supplied to the wheel cylinder increases.

[0007]

As can be understood from the above description of the operation, according to the present invention, the case where the antilock control device is operating and the case where the antilock control device is not operating are divided, and the wheel cylinder corresponding to each case is applied. Since the brake hydraulic pressure is estimated according to the change mode of the brake hydraulic pressure, the brake hydraulic pressure is accurately estimated, and the suspension characteristic of the suspension device is controlled according to the estimated brake hydraulic pressure. The suspension characteristics are also accurately controlled, and the nose dive of the vehicle body during vehicle braking is accurately prevented.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows a vehicle equipped with a brake device 10 and a suspension device 20.

The brake device 10 is provided with a master cylinder 11, and the cylinder 11 supplies a brake hydraulic pressure corresponding to the depression amount of a brake pedal 12 to a wheel cylinder 13.
a to 13d. Each wheel cylinder 13a-1
3d is a disk rotor 1 that rotates integrally with each wheel W1 to W4
By applying a frictional force according to the brake hydraulic pressure to the wheels 4a to 14d, the wheels W1 to W4 are braked. An anti-lock hydraulic control device 15 having a built-in actuator 15a is interposed between the master cylinder 11 and the wheel cylinders 13a to 13d. The hydraulic control device 15 is controlled by a brake microcomputer 16 to control each wheel. The brake hydraulic pressure to the cylinders 13a to 13d is increased, reduced or held to avoid locking the wheels W1 to W4.

The brake microcomputer 16 is R
Program consisting of OM, RAM, CPU, input / output interface (hereinafter referred to as I / O), etc., and stored in the ROM after the ignition switch (not shown) is turned on (corresponding to the flowcharts shown in FIGS. 2 and 3)
Is repeatedly executed every predetermined time, and the actuator 15
control a. Wheel speed sensors 17a to 17d and a brake switch 18 are connected to the microcomputer 16. The wheel speed sensors 17a to 17d are provided corresponding to the wheels W1 to W4, respectively, and are connected to the disk rotor 14
The rotational speeds of a to 14d are detected, and detection signals representing the wheel speeds V (1) to V (4) of the wheels W1 to W4 are output. The brake switch 18 is provided in the vicinity of the brake pedal 12, is normally in an off state, and is turned on when the pedal 12 is depressed.

The suspension device 20 has wheels W1 to W4.
Is provided with shock absorbers 21a to 21d. The damping forces of these shock absorbers 21a to 21d are normally set on the hard side.
Piezoelectric actuators 2 built in 1a to 21d respectively
When a voltage is applied to 2a to 22d, it can be switched to the soft side. Piezoelectric sensors 23a to 23d are provided in the shock absorbers 21a to 21d, respectively. The piezoelectric sensors 23a to 23d detect the axial force applied to the shock absorbers 21a to 21d from the traveling road surface, and the voltage signals E (1) to E (4) that change with a large amplitude as the road surface condition deteriorates (the road surface becomes rough). ) Is output.

These piezoelectric actuators 22a to 22
A suspension microcomputer 24 is connected to the d and the piezoelectric sensors 23a to 23d. The microcomputer 24 includes a ROM, a RAM, a CPU,
After the ignition switch is turned on, the program (corresponding to the flow charts shown in FIGS. 4 and 5) made of I / O and the like is repeatedly executed at predetermined time intervals to control the piezoelectric actuators 22a to 22d. .. Also, a table is provided in the ROM, and the table stores the correction values E _AM for the estimated brake oil pressures P (1) to P (4) shown in the characteristic diagram of FIG. 6 in the form of a map. There is.

Next, the operation of the embodiment configured as described above will be described. When the ignition switch is turned on,
The brake microcomputer 16 executes a program corresponding to the flowchart of FIG. 2 every predetermined time.
Execution of this program begins at step 30,
In step 31, the wheel speeds V (1) to V (4) are read from the wheel speed sensors 17a to 17d, respectively, and in step 32
At, the decelerations α (1) to α (4) of the wheels W1 to W2 are calculated by differentiating the wheel speeds V (1) to V (4). Next, in step 33, the signal from the brake switch 18 is read, and the brake pedal 12 is read based on the signal.
It is determined whether or not is depressed. If the brake pedal 12 is not depressed, "NO" in step 33, that is, the brake switch 18
Is determined to be off, and in step 34, each wheel W
The estimated brake oil pressures P (1) to P (4) corresponding to 1 to W4 are set to "0". After the processing of step 34, the estimated brake oil pressures P (1) to P (4) are transferred to the suspension microcomputer 24 in step 40, and the execution of this program ends in step 41. In this case, in the microcomputer 24, the registers provided in the input / output interface (I / O) are
The transferred estimated estimated brake oil pressures P (1) to P (4) are stored.

On the other hand, when the brake pedal 12 is being depressed, "YES" in the above step 33.
That is, it is determined that the brake switch 18 is in the ON state, and the antilock control process is executed in step 35. This anti-lock control processing is known, and each wheel W1 to W4 is determined based on the read wheel speeds V (1) to V (4) and the calculated wheel decelerations α (1) to α (4). It is determined whether or not the lock is likely to occur. If the wheels W1 to W4 are not in a state in which they are likely to lock, brake hydraulic pressure corresponding to the depression operation of the brake pedal 12 is supplied to the wheel cylinders 13a to 13d. When the wheels W1 to W4 are likely to lock, the microcomputer 16 controls the actuator 15a to operate the antilock hydraulic control device 15 to increase the brake hydraulic pressure supplied to the wheel cylinders 13a to 13d.
By controlling the pressure reduction and holding, the lock of each wheel W1 to W4 is avoided.

After this antilock control processing, the microcomputer 16 executes the processing of steps 36, 38 and 39 to set the variable i (specify each wheel W1 to W4 by 1 to 4) from "1" to "4". The "estimated brake oil pressure calculation routine" is repeatedly executed in step 37 while increasing the value by 1 "to calculate the estimated brake oil pressures P (1) to P (4) corresponding to the wheels W1 to W4. After processing this routine,
Similar to the case described above, the estimated brake oil pressures P (1) to P (4) calculated in step 40 are transferred to the suspension microcomputer 24, and the execution of this program ends in step 41.

The details of the "estimated brake hydraulic pressure calculation routine" are shown in FIG. 3, and it is judged at step 51 whether or not the antilock hydraulic pressure control device 15 is in the operation permission state, and at step 52. It is determined whether the device 15 is in the operating state. The determination of the operation permission state is performed by determining the wheel speed sensors 17a to 17d and the actuator 15
It is to determine whether or not antilock control is impossible due to a failure such as a. Further, the determination of the operating state in step 52 is performed by whether the unlock control in step 35 operates the antilock hydraulic control device 15 to control the increase, decrease, or retention of the brake hydraulic pressure to the wheel cylinders 13a to 13d. It is to determine whether or not. In this case, if the anti-lock control is impossible, or if the anti-lock hydraulic control device 15 is operating even if the same control is possible, “NO” in step 51,
Alternatively, in step 52, the determination is “NO” and the program proceeds to step 53.

In step 53, it is determined whether the variable i is 2 or less. Since this variable i represents each wheel W1 to W4 by 1 to 4, respectively, when the variable i is 2 or less, that is, when the variable i designates the front wheels W1 and W2, “YES” in step 53. , The estimated brake hydraulic pressure P (i) is calculated by executing the calculation of the following expression 1 in step 54. Also, the variable i is 3
In the above case, that is, when the variable i specifies the rear wheels W3 and W4, it is determined to be "NO" in step 53, and the estimated brake hydraulic pressure P ( i) is calculated.

[0018]

[Equation 1] P (i) = K _F · W · α (i) / 4

[0019]

[Number 2] _{P (i) = K R ·} W · α (i) / 4 Here, in the equations 1 and 2, the coefficient K _F, K _R is the front wheel hydraulic pressure conversion coefficient and the rear wheel hydraulic pressure conversion coefficient predetermined And the value W
Is the predetermined vehicle weight (Kg) and the value α (i)
Is the wheel deceleration calculated by the process of step 32. In this way, when the wheels W1 to W4 are not locked or are unlikely to be locked, the wheel cylinders 1
The brake hydraulic pressures for 3a to 13d are wheel deceleration α
Since it is proportional to (1) to α (4), the estimated brake hydraulic pressure P (i) (P (1) to P (4)) calculated by the equations 1 and 2 is in the non-operating state of the antilock hydraulic control device 15. In this case, each brake hydraulic pressure to the wheel cylinders 13a to 13d is accurately represented.

After the processing of steps 54 and 55, at step 56, the initial brake oil pressure P designated by the variable i is set.
₀ (i) is set to the calculated estimated brake oil pressure P (i), and the processing of this "estimated brake oil pressure calculation routine" ends at step 59.

On the other hand, when the anti-lock control is possible and the wheels W1 to W4 are about to be locked, the anti-lock hydraulic control device 15 is operated by the anti-lock control process of the step 35, so that the steps 51, 52
Both are determined to be “YES” in steps 57 and 58.
The process of is executed. In step 57, the variable i
The pressure increase accumulation time T _U (i) and the pressure decrease accumulation time T _D (i) designated by are measured. The pressure increase cumulative time T _U (i) and the pressure decrease cumulative time T _D (i) are controlled by the brake hydraulic pressure to the wheel cylinders 13a to 13d while the antilock hydraulic control device 15 is operating. Each of the two times T _U (i) and T _D (i) is measured by accumulating the pressure increasing and pressure reducing control times of step 35 by the microcomputer 16. It

In step 58, the measured pressure increase cumulative time T _U (i) and pressure decrease cumulative time T _D (i) and the initial brake hydraulic pressure P ₀ (i) set in step 56 are set. Based on this, the estimated brake hydraulic pressure P (i) in the operating state of the anti-lock hydraulic control device 15 is calculated by executing the calculation of the following Expression 3.

[0023]

[Equation 3] P (i) = K _U · T _U (i) −K _D · T _D (i) + P ₀ (i) The coefficients K _U and K _D in the above Equation 3 are anti-lock hydraulic control. When the device 15 controls the brake hydraulic pressure to the wheel cylinders 13a to 13d to increase and decrease pressure, it is a predetermined constant that represents the rate of change of the increased and decreased brake hydraulic pressure with respect to time. As a result, when the unlock hydraulic control device 15 changes from the non-operating state to the operating state,
The estimated brake hydraulic pressure P (i) in the operating state is obtained by adding the increase and decrease amounts by the pressure increasing and pressure reducing control to the estimated brake hydraulic pressure (initial brake hydraulic pressure P ₀ (i)) in the non-operating state. ) Is calculated. in this way,
At the time of sudden braking in which each wheel W1 to W4 is likely to lock, and each brake hydraulic pressure for each wheel cylinder 13a to 13d is not proportional to the wheel deceleration α (1) to α (4), By executing the calculation, the brake hydraulic pressure can be accurately estimated.

On the other hand, the suspension microcomputer 24 also repeatedly executes the program corresponding to the flowchart of FIG. 4 every predetermined time in parallel with the program processing of the brake microcomputer 16.
In this program, the execution is started in step 60, and steps 62 to 71 are performed by increasing the variable i by "1" from "1" to "4" by the processing of steps 61, 70 and 71. The circulation process is repeatedly executed, and then, in step 72, the execution of this program ends. Note that in this case as well, the variable i is 1
4 to designate each wheel W1 to W4.

This circulation process controls each damping force of the shock absorbers 21a to 21d for each circulation, and in the same circulation process, in step 62 thereof,
First, the estimated brake oil pressures P (1) to P (4) transferred from the brake microcomputer 16 and stored in the input / output interface, where the estimated brake oil pressure P (i) designated by the variable i is the CPU Read in.
Then, in step 63, a table in the ROM is referred to based on the read estimated brake hydraulic pressure P (i), and a correction value E _AM corresponding to the hydraulic pressure P (i) is derived.
In this case, the correction value E _AM is set to a value substantially proportional to the estimated brake oil pressure P (i) as shown in FIG.

After the processing of step 63, step 64
At, the reference value E _REF is calculated by executing the calculation of the following Expression 4 based on the predetermined value E ₀ and the correction value E _AM .

[0027]

[Equation 4] E _REF = E ₀ + E _AM As a result of executing the operation of this Equation 4, the reference value E _REF is the predetermined value E.
_It is set to a value larger than ₀ by a correction value E _AM (approximately proportional to the estimated brake oil pressure P (i)), and as shown in FIG. 7A, the brake pedal 12 is depressed and the brake switch 18 is operated. When it is turned on, it gradually increases, and when the depression of the pedal 12 is released and the brake switch 18 is turned off, it rapidly changes to the predetermined value E ₀ . Further, by the processing of steps 65 and 66, the upper limit of the calculated reference value E _REF is limited to the maximum value E _MAX (see FIG. 7).
(See (A)).

Next, of the voltage signals E (1) to E (4) output from the piezoelectric sensors 23a to 23d, the one designated by the variable i is newly read, and at step 68, this new reading is performed. Of the following equation 5 based on each data representing the read voltage signal E (i) _n and the voltage signals E (i) _n-3 , E (i) _n-2 , E (i) _n-1 read in the past. Execution (filtering process)
As a result, the voltage signal E (i) is smoothed.

[0029]

## EQU00005 ## E (i) = {E (i) _n-3 + E (i) _n-2 + E (i) _n-1 + E (i) _n } / 4 After smoothing of this voltage signal E (i) In step 69, the damping force of the shock absorbers 21a to 21d designated by the variable i is controlled by executing the "switching control routine" using the same voltage signal E (i).

The "switching control routine" is shown in detail in FIG. 5, and its execution is started in step 80, and in step 81, the absolute value | E of the voltage signal E (i).
(i) | and the reference value E _REF are compared. In this case, the absolute value | E (i) | If less than the reference value E _REF, it is determined as "NO" in step 81, the process of step 82 to 86 is executed. On the other hand, the shock absorber 21a-
Since the damping force of 21d is normally set to the hard state, the damping force is in the hard state at least in the initial stage, and "NO", that is, the shock absorbers 21a to 21d in step 84 of steps 82 to 86. The damping force of is determined to be in the hard state. Then, in step 86, the first measurement time T ₁ (i) is initialized to “0”, and in step 91, this “switching control routine” is executed.
The processing of is executed. In this state, no voltage is applied to the piezoelectric actuators 22a to 22d, and the damping forces of the shock absorbers 21a to 21d are set to the hard state.

In such a state, when the vehicle travels on a road with poor road surface conditions and the absolute value | E (i) | of the voltage signal E (i) becomes equal to or greater than the reference value E _REF , "YES" in step 81. "
And is determined, "1" is added to the first measurement time T ₁ (i) at step 87, step 88 wherein the first measurement time T in ₁ (i) and the first delay time which is predetermined T _D1 is compared. In this case, since the absolute value | E (i) | has become equal to or greater than the reference value E _REF , the first measurement time T ₁ (i) is the first
It is smaller than the delay time T _D1 and is determined as “NO” in step 88, the second measurement time T ₂ (i) is initialized to “0” in step 90, and the “switching control routine” is performed in step 91. Execution ends. As long as the absolute value | E (i) | is equal to or greater than the reference value E _REF , the processing of steps 81, 87, 88 and 90 is executed in this routine, so that the damping force of the shock absorbers 21a to 21d is Maintained in a hard state.

Further, the absolute value | E (i) | is the reference value E _REF.
If the above state continues for the first delay time T _D1 or more, the first measurement time value T ₁ (i) becomes the first measurement time value T ₁ (i) by the processing of step 87.
The delay time T _D1 or more is exceeded, and “YES” in step 88.
Then, the process of step 89 is executed. In step 89, a voltage is applied to the piezoelectric actuators 22a-22d designated by the variable i. As a result, the corresponding shock absorber 21a
The damping force of ~ 21d is switched to the soft state. After that, in this "switching control routine",
The processing of steps 81 and 87 to 90 continues to be executed.

On the other hand, when the vehicle starts to run on a good road and the absolute value | E (i) | of the voltage signal E (i) becomes less than the reference value E _REF again, it is judged "NO" in step 81, The processes of steps 82 to 86 are executed, and the process of step 82 increases the second measurement time T ₂ (i) by “1”. Immediately after the absolute value | E (i) | becomes less than the reference value E _REF , “NO” in step 83, that is, the second measurement time T ₂ (i) is smaller than the second delay time T _D2. Is determined,
The program proceeds to step 86. Further, this state continues, and the second measurement time value T ₂ (i) becomes the first delay time T
_When it becomes _D2 or more, it is determined in step 83 that “YES”, that is, the second measurement time T ₂ (i) is not less than the second delay time T _D2 , and the processing after step 84 is executed. In this case, since the damping force of the shock absorbers 21a to 21d designated by the variable i is in the soft state, it is judged "YES" at step 84 and the piezoelectric actuators 22a to 22a designated by the variable i at step 85 are determined. The voltage applied to 22d is released. as a result,
The damping force of the corresponding shock absorbers 21a to 21d is returned to the hard state.

In this way, the shock absorber 21
The damping forces of a to 21d are the voltage signals E input from the piezoelectric sensors 23a to 23d, as shown in FIGS.
According to the comparison between (1) to E (4) and the reference value E _REF , the switching is controlled by hardware or software with the first and second delay times T _D1 and T _D2 . On the other hand, the reference value E _REF increases as the estimated brake oil pressures P (1) to P (4) increase, so the shock absorber 21a increases as the oil pressures P (1) to P (4) increase. It becomes difficult to switch the damping force of 21d to the soft side. In other words, this means that the damping forces of the shock absorbers 21a to 21d are controlled to the hard side as the estimated brake oil pressures P (1) to P (4) increase. Therefore, according to the above-described embodiment, the brake oil pressure P supplied to the wheel cylinders 13a to 13d estimated accurately as described above is supplied.
(1) to P (4) allow the nose dive of the vehicle to be accurately controlled.

In the above embodiment, the suspension characteristic of the suspension device 20 is controlled by switching the damping force of the shock absorbers 21a to 21d between soft and hard, but the damping force is continuously controlled. When using a possible shock absorber, the estimated brake hydraulic pressure P (1)
The damping force may be set larger as P (4) increases. In addition, the suspension device 2
In a vehicle provided with a device capable of changing a spring constant such as an air spring device in 0, the suspension characteristic is controlled by changing the spring constant instead of or in addition to the damping force of the shock absorber. You can In this case, the spring constant is increased as the estimated brake oil pressures P (1) to P (4) increase, so that the suspension characteristics of the suspension device are increased as the oil pressures P (1) to P (4) increase. It should be controlled on the hardware side.

[Brief description of drawings]

FIG. 1 is an overall schematic view of a vehicle showing an embodiment of the present invention.

FIG. 2 is a flowchart showing a program executed by the brake microcomputer shown in FIG.

FIG. 3 is a flowchart showing details of an estimated brake hydraulic pressure calculation routine of FIG.

FIG. 4 is a flowchart showing a program executed by the suspension microcomputer of FIG.

5 is a flowchart showing details of the switching control routine of FIG.

FIG. 6 is a change characteristic diagram of a correction value with respect to an estimated brake hydraulic pressure.

7A is a time chart for explaining a change in a reference value E _REF , and FIGS. 7B and 7C are time charts for explaining a switching state of a shock absorber.

[Explanation of symbols]

W1 to W4 ... Wheels, 10 ... Brake device, 11 ... Master cylinder, 12 ... Brake pedal, 13 ... Wheel cylinder, 15 ... Anti-lock hydraulic control device, 16 ... Brake microcomputer, 17a-17d ... Wheel speed sensor, 18 ... Brake switch, 20 ... Suspension device, 21a-21d ... Shock absorber, 24 ... Suspension microcomputer.

Claims (1)

[Claims] 1. A brake hydraulic device for supplying a brake hydraulic pressure to a wheel cylinder in accordance with a depression amount of a brake pedal to apply a braking force to a wheel, and an operation when the wheel is likely to lock due to the application of the braking force. Is applied to a vehicle equipped with an anti-lock control device for avoiding locking of the wheels by increasing / decreasing the brake hydraulic pressure supplied to the wheel cylinder and controlling the suspension characteristics of the suspension device. The control device includes deceleration detecting means for detecting the deceleration of the wheel, and the wheel cylinder based on the detected deceleration when the brake pedal is depressed and the antilock control device is in the inoperative state. First brake oil pressure estimating means for estimating the brake oil pressure supplied to the brake, A second brake hydraulic pressure that estimates the brake hydraulic pressure supplied to the wheel cylinders based on the increase / decrease control time of the brake hydraulic pressure by the antilock control means when the antilock control device is in the operating state when the pedal is depressed. A suspension that controls the suspension device according to the estimating means and the estimated brake hydraulic pressure by the first and second brake hydraulic pressure estimating means, and controls the suspension characteristics of the suspension device toward the hard side as the estimated brake hydraulic pressure increases. An electric control device for a suspension device comprising a characteristic control means.