JP2000283758A - Vehicle attitude detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for detecting the attitude of a vehicle that can detect the pitch behavior of a vehicle by taking into account a slide element in the back and forth direction of the vehicle due to inclination of the vehicle and a bounce element due to passage on projections. SOLUTION: This device for detecting the attitude of a vehicle is provided with a means a1 for detecting the speed of a wheel on the front wheel side to detect the speed of at least one wheel on the front wheel side, a means a2 for detecting the speed of a wheel on the rear wheel side to detect the speed of at least one wheel on the rear wheel side, a means (b) for detecting the speed of a vehicle body to detect the speed of a vehicle body, and a means (c) for computing a pitch behavior to compute the pitch behavior of the vehicle on the basis of a value that is obtained by subtracting the speed of the vehicle detected, by the means (b) from the speed of the wheel on the front wheel side detected by the means a1 and that of the wheel on the rear wheel side detected by the means a2 respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle attitude detecting device used for controlling the attitude of a vehicle.

[0002]

2. Description of the Related Art As a vehicle attitude detecting apparatus as described above, for example, a "suspension control apparatus" described in Japanese Patent Application Laid-Open No. 6-270637 is known. This conventional device is configured to calculate a wheel speed, a pseudo wheel speed and a pseudo vehicle speed from a wheel speed signal detected by each wheel speed sensor, and to suppress and control a change in the attitude of the vehicle based on these calculated values. It was.

[0003]

However, the wheel speed sensor for detecting the wheel speed is provided by a sensor which is provided integrally with the tire and is provided with the number of teeth of a gear-shaped rotor which rotates integrally with the tire. Since the signal is detected as a signal and the number of detected pulse signals in a unit time is measured to measure the number of rotations of the tire, as shown in FIG. When the vehicle is tilted from a horizontal state, a value obtained by adding or subtracting a forward-backward sliding component generated by a sensor provided on the vehicle body rotating around the tire by the tilt angle θ is detected as a wheel speed signal. Therefore, a difference occurs between the wheel speed detection value and the vehicle speed.

[0004] The wheel speed WV is a value obtained by multiplying the radius r of the tire by the rotational angular acceleration ω of the tire. When the tire passes over unevenness on the road surface, the tire deforms as shown in FIG. And the diameter (radius r) of the tire changes (r ₁ → r
₂ ), the rotational angular acceleration ω of the tire changes (ω ₁ → ω ₂ ) due to such a bounce component, whereby a value WV ₂ different from the actual wheel speed WV is detected. Become. Therefore, there has been a problem that an accurate vehicle attitude cannot be detected from the wheel speed signal detected by the wheel speed sensor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and it is an object of the present invention to detect a pitch behavior of a vehicle in consideration of a sliding component in a vehicle longitudinal direction due to a tilt of the vehicle and a bounce component due to passing a projection. It is an object of the present invention to provide a vehicle posture detecting device capable of performing the above.

[0006]

According to a first aspect of the present invention, there is provided a vehicle attitude detecting device for detecting front wheel side wheel speed detecting means for detecting at least one wheel speed of a front wheel. A rear wheel speed detector a2 for detecting at least one wheel speed of a rear wheel, a vehicle speed detector b for detecting a vehicle speed, and a front wheel detected by the front wheel speed detector a1. Pitch behavior calculation means c for calculating the pitch behavior of the vehicle from a value obtained by subtracting the vehicle speed detected by the vehicle speed detection means b from the rear wheel speed detected by the rear wheel speed detection means a2. Means.

According to a second aspect of the present invention, in the vehicle attitude detecting apparatus according to the first aspect, the pitch behavior calculating means c includes the front wheel side wheel speed detecting means a.
A front-wheel-side bounce component calculation circuit for calculating a front-wheel-side bounce component including a forward-backward slide component due to the inclination of the vehicle by subtracting the vehicle-body speed detected by the vehicle-body-speed detection means b from the front-wheel-side wheel speed detected in 1; By subtracting the vehicle speed detected by the vehicle speed detecting means b from the rear wheel speed detected by the rear wheel speed detecting means a2, a rear wheel side bounce component including a forward-backward sliding component due to the inclination of the vehicle is calculated. A rear-wheel-side bounce component calculation circuit for calculating the front-wheel-side bounce component including the front-rear-side bounce component calculated by the front-wheel-side bounce-component calculation unit; And means for calculating a pitch behavior of the vehicle from a difference between the side bounce components.

According to a third aspect of the present invention, in the vehicle attitude detecting apparatus according to the first or second aspect, the vehicle speed detecting means is detected by the front wheel speed detecting means a1. The vehicle speed is determined from an average value of the front wheel speed and the rear wheel speed detected by the rear wheel speed detecting means a2.

[0009]

In the vehicle behavior calculation device according to the first aspect of the present invention,
As described above, the vehicle speed detected by the vehicle speed detecting means b from the front wheel speed detected by the front wheel speed detecting means a1 and the rear wheel speed detected by the rear wheel speed detecting means a2. Is subtracted to obtain a signal in which the longitudinal slide component and the bounce component due to the inclination of the vehicle are combined. By calculating the pitch behavior of the vehicle from both signals, the signal in the longitudinal direction of the vehicle due to the inclination of the vehicle is obtained. It is possible to detect the pitch behavior of the vehicle in consideration of the slide component and the bounce component due to the passage of the protrusion.

According to a second aspect of the present invention, there is provided the vehicle attitude detecting apparatus according to the first aspect, wherein the front wheel side includes a forward / backward slide component due to the inclination of the vehicle calculated by the front wheel side bounce component calculating means a1. The pitch behavior of the vehicle is obtained from the difference between the bounce component and the rear-wheel bounce component including the front-back slide component due to the inclination of the vehicle calculated by the rear-wheel bounce component calculation means a2. Based on the front-wheel-side bounce component and the rear-wheel-side bounce component in which the components are offset by the front and rear wheels, it is possible to detect the pitch behavior of the vehicle without error due to the vehicle longitudinal slide component.

According to a third aspect of the present invention, there is provided a vehicle attitude detecting apparatus according to the first or second aspect, further comprising at least one wheel speed detecting means a1, a2 for the front wheels and the rear wheels. The vehicle speed is obtained from the average value of the detected wheel speeds of the front and rear wheels.
This eliminates the need to provide a new vehicle speed sensor.

[0012]

Embodiments of the present invention will be described with reference to the drawings. FIG. 2 is a configuration explanatory view showing a vehicle suspension device to which the vehicle attitude detecting device according to the embodiment of the present invention is applied, and is interposed between a vehicle body and four wheels, and is provided with four shock absorbers SA _FL and SA. _FR , SA _RL , SA _RR (In addition, when explaining the shock absorber, these four
When referring to them collectively and when describing their common configuration, they are simply denoted by SA. Also, the lower right sign indicates the wheel position, _FL is the front left wheel, _FR is the front right wheel,
_RL indicates the rear wheel left, and _RR indicates the rear wheel right. ) Is provided. Each of the front left wheel and the front right wheel is provided with a wheel speed sensor 1 _FL , 1 _FR for detecting a wheel speed Wv _FL , Wv _FR , respectively. The signals from the speed sensors 1 _FL , 1 _FR are input and the respective shock absorbers SA _FL , SA _FR , S
A control unit 4 for outputting a drive control signal to the pulse motors 3 of A _RL and SA _RR is provided.

FIG. 3 is a system block diagram showing the above configuration. The control unit 4 includes an interface circuit 4a, a CPU 4b, and a drive circuit 4c. The interface circuit 4a includes the left and right wheel speed sensors 1 _FL, 1 wheel speed Wv _FL from _FR, Wv _FR signal is input, the control unit 4, based on these input signals the shock absorbers SA (SA _FL, SA _FR,
SA _RL , SA _RR ) is controlled.

The control unit 4 includes:
The wheel speed Wv from the left and right wheel speed sensors 1 _FL, 1 _{FR
The FL} and Wv _FR signals are input, and the control unit 4 is provided with a signal processing circuit for obtaining the control signal V based on these input signals. The details of this signal processing circuit (FIG. 14) will be described later.

FIG. 4 is a sectional view showing the structure of the shock absorber SA.
A is a cylinder 30, a piston 31 that defines the cylinder 30 in an upper chamber A and a lower chamber B, an outer cylinder 33 in which a reservoir chamber 32 is formed on the outer periphery of the cylinder 30, a lower chamber B and a reservoir chamber 32. Base 34 and piston 31
A guide member 35 for guiding the sliding of the piston rod 7 connected to the outer cylinder 33, a suspension spring 36 interposed between the outer cylinder 33 and the vehicle body, and a bump rubber 37.

FIG. 5 is an enlarged sectional view showing a part of the piston 31. As shown in FIG. 5, the piston 31 has through holes 31a and 31b, and A pressure-side damping valve 20 and an extension-side damping valve 12 that open and close the holes 31a and 31b, respectively, are provided. A stud 38 that penetrates the piston 31 is screwed and fixed to a bound stopper 41 screwed to the tip of the piston rod 7, and the stud 38 bypasses the through holes 31a and 31b. Communication for forming flow paths (extension-side second flow paths E, expansion-side third flow paths F, bypass flow paths G, and compression-side second flow paths J to be described later) that communicate the upper chamber A and the lower chamber B. A hole 39 is formed.
An adjuster 40 for changing the flow path cross-sectional area of the flow path is rotatably provided in 9. Also, stud 38
The communication hole 3 is formed on the outer periphery of the
An expansion-side check valve 17 and a compression-side check valve 22 that allow and shut off the flow on the flow path side formed by 9 are provided. Note that the adjuster 40 is provided with the pulse motor 3.
Is rotated through the control rod 70 (see FIG. 4). Also, studs 38
A first port 21, a second port 13, a third port 18, a fourth port 14, and a fifth port 16 are formed in this order from the top.

On the other hand, the adjuster 40 has a hollow portion 19, a first horizontal hole 24 and a second horizontal hole 25 communicating between the inside and the outside, and a vertical groove 23 formed in the outer peripheral portion. I have.

Therefore, between the upper chamber A and the lower chamber B, a through-hole 31 is formed as a flow path through which fluid can flow during the extension stroke.
b, the inside of the extension side damping valve 12 is opened to open the lower chamber B
, The second port 13, the vertical groove 23,
Via the second port 13, the vertical groove 23, and the fifth port 16 via the fourth port 14, the outer peripheral side of the extension side damping valve 12 is opened to open the outer peripheral side of the extension side damping valve 12 to reach the lower chamber B, Then, the extension side check valve 17 is opened to open the extension side third flow path F to the lower chamber B, and the bypass to the lower chamber B via the third port 18, the second horizontal hole 25, and the hollow portion 19. There are four flow paths G. In addition, as a flow path through which a fluid can flow during the pressure stroke, the pressure side first valve that opens the pressure side damping valve 20 through the through hole 31a
Channel H, hollow portion 19, first lateral hole 24, first port 21
And the bypass side flow to the upper chamber A via the hollow portion 19, the second horizontal hole 25, and the third port 18 by opening the pressure side check valve 22 to the upper chamber A via Road G
And three flow paths.

That is, the shock absorber SA is configured such that the damping force characteristic can be changed in multiple steps by rotating the adjuster 40 with the characteristics shown in FIG. 6 on both the extension side and the compression side. That is, as shown in FIG.
The state in which both pressure sides are soft (hereinafter, soft area SS
When the adjuster 40 is rotated counterclockwise from
When the damping force characteristic can be changed in multiple stages only on the extension side and the compression side is fixed to the low damping force characteristic (hereinafter referred to as the extension side hard area HS). Conversely, when the adjuster 40 is rotated clockwise, Only the compression side has a structure in which the damping force characteristic can be changed in multiple stages, and the extension side is a region fixed to the low damping force characteristic (hereinafter referred to as a compression side hard region SH).

Incidentally, in FIG. 7, when the adjuster 40 is arranged at the positions (1), (2) and (3),
The KK section, the LL section, the MM section, and the NN section in FIG. 5 are shown in FIGS. 8, 9, and 10, respectively, and the damping force characteristics at each position are shown in FIGS. ,
13.

Next, the control operation of the control unit 4
Of the left and right wheel speed sensors 1 _FL, 1_FRWheels from
Speed Wv_FL, Wv_FREach shock absorber based on the signal
Signal processing for obtaining control signal V for controlling damping force characteristics of bus SA
The configuration of the circuit will be described based on the block diagram of FIG.
You.

[0022] First, in B1, B2, and converts the wheel speed pulse signal from the front-wheel-side left and right wheel speed sensors 1 _FL, 1 _FR front side lateral wheel speeds Wv _FL, the Wv _FR signal. The following B3
So determined front-wheel-side left and right wheel speeds Wv _FL, the average value of Wv _FR signal _{(= (Wv FL + Wv FR} ) / 2).

At B4, the vehicle speed Sv is calculated from the average value of the front left and right wheel speeds. At B5, the front bounce speed Vgfb is obtained based on the front bounce behavior transfer function Gf (s) of the vehicle. Then, the rear bounce speed Vgrb is determined based on the rear bounce behavior transfer function Gr (s) of the vehicle.

At B6 following B5, the vehicle speed Sv is subtracted from the front bounce speed Vgfb to obtain
Front bounce speed VGF including forward and backward sliding components
B is obtained, and in B8 following B7, the body bounce speed Sv is subtracted from the rear bounce speed Vgrb to obtain a rear bounce speed VGR including a forward-backward sliding component.
B is required.

At B9 subsequent to B6 and B8, the pitch behavior transfer function Gp (s) of the vehicle is calculated from the difference between the front bounce speed VGFB including the forward and backward slide components and the rear bounce speed VGRB including the forward and backward slide components. Is used to determine the pitch speed Vgp of the vehicle. That is, the front bounce speed VGF including the front-back direction slide component
Rear bounce speed VGR including B and longitudinal slide components
By subtracting B, the pitch speed Vgp of the vehicle in a state in which the two front-to-back sliding components are cancelled is obtained. Then, in B10, the vehicle pitch speed Vgp is subjected to drift prevention and noise cut processing by a band-pass filter to obtain a vehicle pitch rate _VP signal.

[0026] In B11 following the B6, drift prevent front bounce rate VGFB vehicle band pass filter, by noise cut process, the front bounce rate V _BF signal of the vehicle is determined and also the B8
In B12 followed, the drift preventing rear bounce rate VGRB vehicle band pass filter, by noise cut process, the rear bounce rate V _BR signal of the vehicle is determined.

On the other hand, in B13 following B1 and B2,
The difference between the front left and right wheel speeds Wv _FL and Wv _FR signals (= W
v _FL −Wv _FR ), and in B14, the roll behavior transfer function Gr of the vehicle with respect to the front-wheel-side left / right wheel speed difference is calculated.
Based on (s), the roll speed Vgr of the vehicle is determined.

[0028] In subsequent B15, drift prevent roll speed Vgr vehicle bandpass filter, by noise cut process, roll rate V _R signal of the vehicle is determined.

At B16 following B10, B11, B12, and B15, the shock absorbers SA (SA _FL , SA _FR , SA _RL , S
A _RR ) damping force characteristic control control signal V (V _FL , V _FR , V
_RL , V _RR ). _{V FL = K BF · V BF} + K PF · V P -K RF · V R V FR = K BF · V BF + K PF · V P + K RF · V R V RL = K BR · V BR -K PR · V _{P -K RR · V R V RR} = K BR · V BR -K PR · V P + K RR · V R in addition, K _BF is the front-wheel-side bounce coefficient, K _BR is the rear-wheel-side bounce coefficient, K _PF is the front-wheel-side The pitch coefficient, K _PR is a rear wheel side pitch coefficient, K _RF is a front wheel side roll coefficient, and K _RR is a rear wheel side roll coefficient.

Next, the contents of the damping force characteristic control operation of the shock absorber SA in the control unit 4 will be described with reference to the flowchart of FIG. In addition,
This damping force characteristic control is performed by each of the shock absorbers SA _FL , S
This is performed for each of A _FR , SA _RL , and SA _RR .

[0031] At step 101, the control signal V is determined whether it exceeds the positive dead zone V _NC, each shock absorber SA proceeds to step 102 if YES and control the extension phase hard region HS, NO Then step 10
Proceed to 3.

[0032] At step 103, the control signal V is determined whether or not below the negative dead zone -V _NC, the shock absorbers proceeds to step 104 if YES SA
To the pressure side hard area SH, and if NO, the routine proceeds to step 105.

Step 105 is a process when NO is determined in steps 101 and 103, that is, when the value of the control signal V is within the range from the negative dead zone -V _NC to the positive dead zone V _NC. At this time, each shock absorber SA is controlled to the soft area SS.

Next, the operation of the damping force characteristic control will be described with reference to the time chart of FIG. When the control signal V changes as shown in this figure, as shown in the figure, the control signal V
Is within the range from the negative dead zone −V _NC to the positive dead zone V _NC , the shock absorber SA is controlled to the soft region SS.

When the value of the control signal V exceeds the positive dead zone V _NC , the compression side damping force characteristic is controlled to the expansion side hard region HS to fix the compression side damping force characteristic to the soft side while the expansion side damping force characteristic ( The target damping force characteristic position P _T ) is calculated based on the following equation:
It is changed in proportion to the control signal V. P _T = (V−V _NC ) / (V _H −V _NC ) × P _T-max where V _H is the extension-side proportional range, and P _T-max is the extension-side maximum damping force characteristic position. That is, the target damping force characteristic position _PT on the extension side is variably controlled to the hardware characteristic side in proportion to the value of the control signal V.

When the value of the control signal V becomes a negative value,
The compression side hard region SH is controlled to fix the extension side damping force characteristic to the soft characteristic, while the compression side damping force characteristic (target damping force characteristic position P _C ) is proportional to the control signal V based on the following equation. change. P _C = (V−V _NC ) / (V _H −V _NC ) × P _C-max where V _H is the compression side proportional range, and P _C-max is the compression side maximum damping force characteristic position. That is, the target damping force characteristic position P _C of the compression side in proportion to the control signal V value is variably controlled in the hard characteristics side.

Next, of the damping force characteristic control operations of the control unit 4, mainly the switching operation state of the control area of the shock absorber SA will be described with reference to the time chart of FIG.

In the time chart of FIG.
Is a state in which the control signal V based on the sprung vertical speed is reversed from a negative value (downward) to a positive value (upward). At this time, the relative speed is still a negative value (the stroke of the shock absorber SA is At this time, the shock absorber S is determined based on the direction of the control signal V.
A is controlled to the extension side hard region HS, and therefore, in this region, the pressure stroke side which is the stroke of the shock absorber SA at that time has the soft characteristic.

An area b is an area where the control signal V remains at a positive value (upward) and the relative speed is switched from a negative value to a positive value (the stroke of the shock absorber SA is on the extension stroke side). Therefore, at this time, the shock absorber SA is controlled to the extension side hard region HS based on the direction of the control signal V, and the stroke of the shock absorber is also the extension stroke. The extension stroke, which is the stroke of the absorber SA, has hardware characteristics proportional to the value of the control signal V.

Area c is a state where the control signal V is reversed from a positive value (upward) to a negative value (downward).
At this time, the relative speed is still a positive value (shock absorber S
Since the stroke A is the extension stroke side), at this time, the shock absorber SA is controlled to the compression-side hard region SH based on the direction of the control signal V. Therefore, in this region, The extension stroke side of the shock absorber SA has soft characteristics.

The region d is a region in which the control signal V remains a negative value (downward) and the relative speed changes from a positive value to a negative value (the stroke of the shock absorber SA is on the extension stroke side). At this time, the shock absorber SA is controlled to the compression-side hard area SH based on the direction of the control signal V, and the stroke of the shock absorber is also the compression stroke,
Therefore, in this area, the shock absorber SA at that time is
The pressure stroke side, which is the stroke of the above, has hardware characteristics proportional to the value of the control signal V.

As described above, in the embodiment of the present invention, when the control signal V based on the sprung vertical speed and the relative speed have the same sign (region b, region d), the stroke of the shock absorber SA at that time. Side is controlled to a hard characteristic, and when the sign is different (regions a and c), the stroke side of the shock absorber SA at that time is controlled to a soft characteristic, which is the same as the damping force characteristic control based on the skyhook theory. Control will be performed. Further, in the embodiment of the present invention, when the stroke of the shock absorber SA is switched, that is, when shifting from the area a to the area b and from the area c to the area d (from the soft characteristic to the hard characteristic),
Since the damping force characteristic position on the stroke side to be switched has already been switched to the hard characteristic side in the previous areas a and c, the switching from the soft characteristic to the hard characteristic is performed without time delay.

As described above, in the vehicle attitude detecting device according to the embodiment of the present invention, the difference value obtained by subtracting the rear bounce speed VGRB including the forward / backward sliding component from the front bounce speed VGFB including the forward / backward sliding component. From the above, based on the pitch behavior transfer function Gp (s) of the vehicle, the vehicle pitch speed Vgp is obtained,
The pitch speed Vgp of the vehicle in a state in which the front-rear-side and rear-wheel-side forward and backward slide components are cancelled can be obtained.
The effect is obtained that the vehicle attitude can be controlled and suppressed with high accuracy.

Further, the front left and right right and left wheel speed sensors 1_FL, 1
_FRLeft and right wheel speeds WV detected by _FL, WV_FRSignal flat
By calculating the vehicle speed Sv from the average value,
It is no longer necessary to provide a vehicle speed sensor in
It will be possible to minimize it.

Although the embodiments of the present invention have been described above, the specific configuration is not limited to the embodiments of the present invention, and even if there is a design change or the like within a range not departing from the gist of the present invention, the present invention is not limited thereto. Included in the invention.

For example, in the embodiment of the present invention, the vehicle speed Sv is obtained from the average value of the left and right wheel speed WV _FL and WV _FR signals detected by the front left and right wheel speed sensors 1 _FL and 1 _FR . However, a vehicle speed sensor that directly detects the vehicle speed from the transmission differential of the vehicle may be provided separately, and in this case, the detection accuracy of the vehicle behavior can be further improved.

In the embodiment of the present invention, when the damping force characteristic of one of the expansion stroke and the compression stroke is controlled to the hard characteristic side, the damping force characteristic of the other stroke side is set to the soft characteristic. Although an example using a shock absorber with a structure fixed to the characteristics has been shown, the present invention can be applied to a system using a shock absorber with a structure in which the damping force characteristics of the extension stroke and the compression stroke change in the same direction. it can.

[0048]

In order to achieve the above object, a vehicle attitude detecting device according to a first aspect of the present invention includes a front wheel side wheel speed detecting means for detecting a wheel speed of at least one front wheel, and a rear wheel side detecting device. Rear wheel speed detecting means for detecting at least one wheel speed, vehicle speed detecting means for detecting vehicle speed, front wheel speed detected by the front wheel speed detecting means, and rear wheel speed. Pitch behavior calculating means for calculating the pitch behavior of the vehicle from a value obtained by subtracting the vehicle speed detected by the vehicle speed detecting means from the rear wheel speed detected by the detecting means. By calculating the pitch behavior of the vehicle from both signals obtained by combining the forward / backward slide component and the bounce component due to the vehicle inclination, the vehicle forward / backward slide component due to the vehicle inclination and the projection passing Effect that it is possible to detect the pitch behavior of the vehicle in consideration of the bounce component with.

According to a second aspect of the present invention, in the vehicle attitude detecting apparatus according to the first aspect, the pitch behavior calculating means calculates a value based on the front wheel speed detected by the front wheel speed detecting means. A front-wheel-side bounce component calculation circuit that calculates a front-wheel-side bounce component including a front-back slide component due to the inclination of the vehicle by subtracting the vehicle-body speed detected by the vehicle-body speed detection unit; A rear-wheel-side bounce component calculation circuit for calculating a rear-wheel-side bounce component including a forward-backward slide component due to the inclination of the vehicle by subtracting the vehicle-body speed detected by the vehicle-body-speed detection means from the rear-wheel-side wheel speed; The front bounce component including the front-back slide component calculated by the side bounce component calculation unit and the front-back slide component calculated by the rear wheel bounce component calculation unit are included. The pitch component of the vehicle is calculated from the difference between the bounce components on the rear wheel side and the pitch behavior calculation circuit that calculates the pitch behavior of the vehicle. Based on the front-wheel-side bounce component and the rear-wheel-side bounce component, it is possible to detect the pitch behavior of the vehicle without error due to the vehicle longitudinal slide component.

According to a third aspect of the present invention, in the vehicle attitude detecting apparatus according to the first or second aspect, the vehicle body speed detecting means may include a front wheel side wheel speed detected by the front wheel side wheel speed detecting means. Since the vehicle speed is obtained from the average value of the wheel speed and the rear wheel speed detected by the rear wheel speed detecting device, it is not necessary to newly provide a vehicle speed sensor. Therefore, the number of sensors can be minimized.

[Brief description of the drawings]

FIG. 1 is a view corresponding to a claim showing a vehicle posture detecting device of the present invention.

FIG. 2 is a configuration explanatory view showing a vehicle suspension device to which the vehicle posture detection device according to the embodiment of the present invention is applied.

FIG. 3 is a system block diagram showing a vehicle suspension device to which the vehicle posture detection device according to the embodiment of the present invention is applied.

FIG. 4 is a sectional view showing a shock absorber of the vehicle suspension device.

FIG. 5 is an enlarged sectional view showing a main part of the shock absorber.

FIG. 6 is a damping force characteristic diagram corresponding to a piston speed of the shock absorber.

FIG. 7 is a damping force characteristic diagram corresponding to a step position of a pulse motor of the shock absorber.

8 is a sectional view showing a state in which the adjuster of the shock absorber is arranged at a position (1) in FIG. 7, (A) is a sectional view taken along the line KK of FIG. 5, and (B) is a sectional view of FIG. L-
FIG. 5C is an L-sectional view and an MM sectional view, and FIG.

9 is a sectional view showing a state in which the adjuster of the shock absorber is arranged at a position (2) in FIG. 7, (A) is a sectional view taken along line KK of FIG. 5, and (B) is a sectional view of FIG. L-
FIG. 5C is an L-sectional view and an MM sectional view, and FIG.

10 is a sectional view showing a state in which the shock absorber adjuster is arranged at a position (3) in FIG. 7, (A) is a sectional view taken along the line KK in FIG. 5, and (B) is a sectional view in FIG. L-
FIG. 5C is an L-sectional view and an MM sectional view, and FIG.

FIG. 11 is a damping force characteristic diagram when the shock absorber is on the extension side hard.

FIG. 12 is a damping force characteristic diagram of the shock absorber in a soft state on an extension side and a compression side.

FIG. 13 is a damping force characteristic diagram of the shock absorber in a pressure-side hard state.

FIG. 14 is a block diagram showing the contents of a signal processing circuit for obtaining a control signal in the control operation of the control unit according to the embodiment of the present invention.

FIG. 15 is a flowchart showing a damping force characteristic control operation of the control unit according to the embodiment of the present invention.

FIG. 16 is a time chart showing a damping force characteristic control operation of the control unit according to the embodiment of the present invention.

FIG. 17 is a diagram for explaining a forward-backward sliding component of a wheel speed signal when the vehicle is tilted.

FIG. 18 is a diagram for explaining a bounce component of a wheel speed signal when passing a protrusion.

[Explanation of symbols]

 a1 front wheel left wheel speed detecting means a2 front wheel right wheel speed detecting means b body speed detecting means c pitch behavior calculating means

Claims (3)

[Claims] 1. A front wheel speed detecting means for detecting a wheel speed of at least one wheel on a front wheel side; a rear wheel speed detecting means for detecting a wheel speed of at least one wheel on a rear wheel side; Vehicle body speed detecting means, a vehicle body detected by the vehicle body speed detecting means from a front wheel side wheel speed detected by the front wheel side wheel speed detecting means and a rear wheel side wheel speed detected by the rear wheel side wheel speed detecting means And a pitch behavior calculating means for calculating a pitch behavior of the vehicle from a value obtained by subtracting the speed. 2. A front / rear sliding component due to a lean of a vehicle, wherein the pitch behavior calculating means subtracts a vehicle speed detected by the vehicle speed detecting means from a front wheel speed detected by the front wheel speed detecting means. A front-wheel-side bounce component calculation circuit that calculates a front-wheel-side bounce component including: subtracting the vehicle speed detected by the vehicle-body speed detection unit from the rear-wheel-side wheel speed detected by the rear-wheel-side wheel speed detection unit A rear-wheel-side bounce component calculation circuit for calculating a rear-wheel-side bounce component including a front-rear slide component due to the inclination of the vehicle; And a pitch behavior calculation circuit for calculating a pitch behavior of the vehicle from a difference between the bounce components of the rear wheels including the front-back slide component calculated by the bounce component calculation means. And vehicle attitude detecting device according to claim 1, wherein the are. 3. The vehicle body speed detecting means calculates a vehicle body speed from an average value of front wheel side wheel speed detected by the front wheel side wheel speed detecting means and rear wheel side wheel speed detected by rear wheel side wheel speed detecting means. The vehicle attitude detecting device according to claim 1, wherein the vehicle attitude detecting device is configured to obtain a speed.