JPH1016741A - Anti-skid control operation status detection device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To indirectly detect an operation state of an anti-skid control, thereby omitting signal wiring from an anti-skid control controller and simplifying the controller, thereby improving vehicle mountability and cost. Provided is an anti-skid control operation state detection device capable of reducing the amount of noise. A vertical behavior detecting means for detecting a vertical behavior of a vehicle, and a resonance of a high frequency vibration generated in the vehicle at the time of an anti-skid control operation from a vertical behavior signal of the vehicle detected by the vertical behavior detecting means. Judgment signal forming means b for extracting a frequency band component as a judgment signal, and anti-skid control for judging that the anti-skid control is activated when the judgment signal extracted by the judgment signal forming means b exceeds a predetermined threshold value. Operating state determining means c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting an operation state of an anti-skid control used as one of control signals in a damping force characteristic control of a shock absorber or the like.

[0002]

2. Description of the Related Art Conventionally, as an apparatus for detecting an anti-skid control operation state used in damping force characteristic control of a suspension, for example, Japanese Patent Application Laid-Open No. 3-1091 is disclosed.
Japanese Patent Application Publication No. 14, “Suspension and brake integrated control device” is known.

[0003] This "comprehensive control system for suspension and brake" includes a controller for controlling the damping force characteristic of the suspension and a controller for anti-skid control. When the anti-skid control is in operation, the suspension is controlled by the anti-skid control controller. A signal indicating that the anti-skid control operation is being performed is input to the damping force characteristic control controller of the above, and the damping force characteristic control controller is configured to control the suspension damping force characteristic to the software side based on the input signal. It was what was done. The anti-skid control operation state is detected using an anti-skid control operation start signal in the anti-skid control controller.

[0004]

However, in the prior art, as described above, the anti-skid control operation state is detected by using the anti-skid control operation start signal in the anti-skid control operation signal. It is necessary to connect the controller for damping force characteristics and the controller for damping force characteristics with wiring, and to communicate between both controllers. Therefore, it is inferior in the in-vehicle property, and both controllers are complicated and expensive. was there.

The present invention has been made in view of the above-mentioned conventional problems. By indirectly detecting the operating state of the anti-skid control, the omission of signal wiring from the anti-skid control controller and the elimination of the controller are realized. It is an object of the present invention to provide an anti-skid control operating state detecting device that can be simplified and thus can improve vehicle mountability and reduce costs.

[0006]

In order to achieve the above-mentioned object, an anti-skid control operating state detecting device according to the present invention comprises an up-down detecting device for detecting the up-down behavior of a vehicle as shown in FIG. Direction behavior detection means a, and a determination signal formation for extracting a resonance frequency band component of high-frequency vibration generated in the vehicle at the time of anti-skid control operation as a determination signal from the vertical behavior signal of the vehicle detected by the vertical behavior detection means a Means b; and anti-skid control operating state determining means c for determining that the anti-skid control is in operation when the determination signal extracted by the determination signal forming means b exceeds a predetermined threshold value. Means.

[0007]

According to the anti-skid control operation state detecting device of the present invention, as described above, the determination signal of the resonance frequency band component of the high-frequency vibration generated in the vehicle at the time of the anti-skid control operation is extracted from the vertical movement signal of the vehicle, The anti-skid control operation state can be detected based on this determination signal, thereby eliminating the need for signal wiring from the anti-skid control control unit.
The anti-skid control operation state is detected, and this can be used, for example, as one of the signals for controlling the damping force characteristic of the suspension. Therefore, for example, in a vehicle equipped with an anti-skid control device as standard equipment, even if an electronically controlled suspension system that uses the anti-skid control operation state signal as one of the suspension damping force characteristic control signals is set as an option, Since it can be installed independently without changing the structure of the control unit for skid control or adding signal wiring from the control unit for anti-skid control,
Option setting costs can be minimized.

[0008]

Embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 2 shows Embodiment 1 of the present invention.
FIG. 2 is an explanatory view showing a configuration of a vehicle suspension device provided with an anti-skid control operation state detection device of the present invention, which is interposed between a vehicle body and four wheels and is provided with four shock absorbers SA _FL , S
A _FR , SA _RL , SA _RR (Note that in describing the shock absorber, when these four are collectively referred to, and when describing their common configuration, they are simply indicated as SA. Indicates the wheel position.
_FL indicates front wheel left, _FR indicates front wheel right, _RL indicates rear wheel left, and _RR indicates rear wheel right. ) Is provided. Then, the acceleration G in the vertical direction is applied to the vehicle body at each wheel position on the sprung side.
(Spring-up vertical acceleration sensor (hereinafter referred to as sprung-up vertical G sensor) 1 for detecting (G _FL , G _FR , G _RL , G _RR ) 1
(1 _FL , 1 _FR , 1 _RL , 1 _RR ) are provided, and each of the front left and right wheels has a wheel speed W _{V- FL} ,
W _V-FR for detecting a wheel speed sensor 2 _FL, 2 _FR are provided,
Further, the rear differential wheel speed sensors 2 _RS for detecting a wheel speed W _V-RS of the rear wheel side is provided in, also, the brake switch 5 has been omitted in this view for detecting an operating state of the brake pedal is provided Have been.

Further, near the driver's seat, each sprung upper and lower G sensor 1 (1 _FL , 1 _FR , 1 _RL , 1 _RR ), and
A control unit 4 for controlling a damping force characteristic, which receives a signal from a brake switch 5 and outputs a drive control signal to a pulse motor 3 of each of the shock absorbers SA _FL , SA _FR , SA _RL , and SA _RR , and each wheel speed sensor 2 (2 _FL , 2 _FR ,
2 _RS ), and an anti-skid control unit 6 for controlling the brake fluid pressure on the wheel cylinder of each wheel is provided. In addition,
The description of the specific contents of the anti-skid control is omitted.

FIG. 3 is a system block diagram showing the above configuration. The control unit 4 for controlling damping force characteristics includes an interface circuit 4a, a CPU 4b, and a drive circuit 4c. The sprung vertical acceleration G (G _FL , G _FR , G _RL , G _RR ) signal from the upper and lower G sensor 1 (1 _FL , 1 _FR , 1 _RL , 1 _RR ),
Further, an ON-OFF signal from the brake switch 5 is input, and the damping force characteristic control unit 4 controls each of the shock absorbers SA (SA _FL , SA _FR , SA _RL , SA _RR ) based on these input signals. Damping force characteristic control is performed.

The damping force characteristic control control unit 4 includes the sprung upper and lower G sensors 1 (1 _FL , 1 _FL) .
1 _FR , 1 _RL , 1 _RR ), the sprung vertical acceleration G (G _FL ,
G _FR , G _RL , G _RR ) signals, a first signal processing circuit (FIG. 14) for obtaining a sprung vertical speed signal and a sprung unsprung relative speed signal at each wheel position, and an anti-skid control operation A judgment signal S _B for detecting a state
Is provided with a second signal processing circuit (FIG. 18). The details of these signal processing circuits 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 formed therein, and A compression-side damping valve 20 and an extension-side damping valve 12 for opening and closing 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 communication hole 3 in accordance with the direction of fluid flow.
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 in 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, and the second port 13, the vertical groove 23, and the fifth port 16. 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
, The pressure-side second flow path J that opens the pressure-side check valve 22 to reach the upper chamber A through the air passage, and the bypass flow that reaches the upper chamber A through the hollow portion 19, the second horizontal hole 25, and the third port 18. 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 a region fixed to the low damping force characteristic (hereinafter referred to as the extension side hard region 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).

In FIG. 7, the KK section, the LL section, the MM section, and the NN section in FIG. 8, 9 and 10 and the damping force characteristics at each position are shown in FIGS.

Next, among the control operations of the damping force characteristic control control unit 4, the first signal processing circuit for determining the sprung vertical speed Δx and the sprung-unsprung relative speed (Δx−Δx ₀ ). The configuration will be described based on the block diagram of FIG.

First, in B1, a phase delay compensation formula is used,
Each sprung vertical acceleration G (G _FL , G _FR , G _RL , G _FL , G _RL , G _L ) detected by each sprung vertical G sensor 1 (1 _FL , 1 _FR , 1 _RL , 1 _RR )
G _RR ) is converted into a sprung vertical speed signal at each tower position.

The general expression of the phase delay compensation can be expressed by the following transfer function expression (1). G _(S) = (AS + 1) / (BS + 1) (1) (A <B) Then, the frequency band (0.5 Hz to 3
Hz), has the same phase and gain characteristics as the case of integration (1 / S), and as a phase lag compensation equation for lowering the gain on the low frequency side (up to 0.05 Hz), the following transfer function equation (2 ) Is used.

G _(S) = (0.001 S + 1) / (10S + 1) × γ (2) where γ is a signal and gain characteristic when speed conversion is performed by integration (1 / S). And γ = 10 in the first embodiment of the present invention. As a result, as shown in the solid line gain characteristics in FIG. 15A and the solid line phase characteristics in FIG. 15B, the frequency band (0.5 Hz to 3 Hz) required for damping force characteristic control is obtained.
2), only the gain on the low frequency side is reduced without deteriorating the phase characteristics. Note that FIG.
Dotted lines (a) and (b) show the gain characteristic and phase characteristic of the sprung vertical velocity signal that has been velocity-converted by integration (1 / S). In B2, band-pass filter processing is performed to cut off components other than the target frequency band to be controlled. That is, the band-pass filter BPF is composed of a second-order high-pass filter HPF (0.3 Hz) and a second-order low-pass filter LPF (4 Hz), and has a sprung vertical velocity that targets a sprung resonance frequency band of the vehicle. Δx (Δx _FL , Δ
x _FR , Δx _RL , Δx _RR ) signal.

On the other hand, in B3, as shown in the following equation (3),
Using the transfer function Gu _(S) from each sprung vertical acceleration to the sprung-unsprung relative speed, the vertical acceleration G (G _FL , G _FR , G _RL ,
G _RR ) signal, the relative speed between sprung and unsprung at each tower position (Δx−Δx ₀ ) [(Δx−Δx ₀ ) _FL , (Δx−
Δx ₀ ) _FR , (Δx−Δx ₀ ) _RL , (Δx−Δx
₀ ) _{Find the RR} ] signal. Gu _(S) =-mss / (cs + k) (3) where m is a sprung mass, c is a damping coefficient of the suspension, and k is a spring constant of the suspension.

Next, of the damping force characteristic control operation of the shock absorber SA in the damping force characteristic control unit 4, the contents of the normal control by the basic control unit will be described with reference to the flowchart of FIG. In addition,
This normal 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 .

In step 101, the sprung vertical speed Δx
Is determined to be a positive value. If YES, the flow proceeds to step 102 to control each shock absorber SA to the extension-side hard region HS. If NO, the flow proceeds to step 103.

In step 103, the sprung vertical velocity Δx
Is determined to be a negative value. If YES, the routine proceeds to step 104, where each shock absorber SA is controlled to the pressure-side hard area SH, and if NO, the routine proceeds to step 105.

Step 105 is a processing step when NO is determined in steps 101 and 103, that is, when the value of the sprung vertical velocity Δx is 0,
At this time, each shock absorber SA is
To control.

Next, the operation of the damping force characteristic control will be described with reference to the time chart of FIG. The sprung vertical speed Δx is
When the value changes as shown in this figure, as shown in the figure, when the value of the sprung vertical velocity Δx is 0, the shock absorber SA is controlled to the soft area SS.

When the value of the sprung vertical speed Δx becomes a positive value, 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 characteristic, while the expansion side damping force characteristic (target The damping force characteristic position P _T ) is changed in proportion to the sprung vertical speed Δx based on the following equation (4). P _T = α · Δx · K (4) where α is a constant on the extension side, and K is a relative speed between the sprung and unsprung (Δx −Δx ₀ ).

When the value of the sprung vertical velocity Δx 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) is set. The characteristic position P _C ) is calculated based on the following equation (5).
It changes in proportion to the sprung vertical speed Δx. P _C = β · Δx · K (5) where β is a pressure-side constant.

Next, among the damping force characteristic control operations of the damping force characteristic control unit 4, mainly the switching operation state of the control region 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 sprung vertical speed Δx is reversed from a negative value (downward) to a positive value (upward). At this time, the relative speed (Δx−Δx ₀ ) is still a negative value (shock absorber SA).
Is a pressure stroke side), and at this time, the shock absorber SA is controlled to the extension side hard region HS based on the direction of the sprung vertical speed Δx,
Therefore, in this area, the shock absorber SA at that time is
The pressure stroke side, which is the stroke of, has soft characteristics.

In region b, the sprung vertical speed Δx remains a positive value (upward), and the relative speed (Δx−Δx ₀ ) changes from a negative value to a positive value (the stroke of the shock absorber SA is the extension stroke). Side), the shock absorber SA is controlled to the extension side hard area HS based on the direction of the sprung vertical speed Δx at this time, and the stroke of the shock absorber is also the extension stroke. Accordingly, in this region, the extension stroke, which is the stroke of the shock absorber SA at that time, has a hardware characteristic proportional to the value of the sprung vertical speed Δx.

The area c is a state in which the sprung vertical velocity Δx is reversed from a positive value (upward) to a negative value (downward). At this time, the relative velocity (Δx−Δx ₀ ) is still positive. (The stroke of the shock absorber SA is on the extension stroke side), and at this time, the sprung vertical velocity Δx
The shock absorber SA is controlled to the pressure side hard region SH based on the direction of the shock absorber SA. Therefore, in this region, the extension stroke which is the stroke of the shock absorber SA at that time has the soft characteristic.

In the area d, the sprung vertical speed Δx remains a negative value (downward), and the relative speed (Δx−Δx ₀ ) changes from a positive value to a negative value (the stroke of the shock absorber SA is the extension stroke). At this time, the shock absorber SA is controlled to the compression-side hard region SH based on the direction of the sprung vertical velocity Δx, and the stroke of the shock absorber is also the compression stroke. In this region, the pressure stroke side, which is the stroke of the shock absorber SA at that time, has a hard characteristic proportional to the value of the sprung vertical speed Δx.

As described above, in the first embodiment of the present invention, when the sprung vertical speed Δx and the relative speed (Δx−Δx ₀ ) have the same sign (region b, region d), the shock absorber at that time is used. Damping force characteristic control based on the skyhook theory, in which the stroke side of the SA is controlled to hard characteristics, and when the sign is different (region a, region c), the stroke side of the shock absorber SA at that time is controlled to soft characteristics. Will be performed. Further, in the first 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.

Next, among the control operation of the damping force characteristic control for the control unit 4, the configuration of the second signal processing circuit for obtaining a determination signal S _B for detecting the anti-skid control operation state, the block diagram of FIG. 18 , And a time chart of FIG.

Firstly, the C1 block diagram of FIG. 18, as shown in (b) of FIG. 21, the sprung mass vertical acceleration G _FR signal detected on right front spring vertical G sensors 1 _FR, cut-off frequency 100Hz , The resonance frequency band component signal of the high frequency vibration generated in the vehicle at the time of the anti-skid control operation is extracted, and in C2, the absolute value of the resonance frequency band component signal of the high frequency vibration is obtained. Then, in the following C3, the absolute value is processed by a low-pass filter LPF of 2 Hz, thereby obtaining FIG.
As shown in the (c), obtaining the averaged decision signal S _B.

That is, during the operation of the anti-skid control, high-frequency vibration is generated in the brake pipe by repeatedly reducing, maintaining, and re-increasing the brake fluid pressure. From the vertical acceleration G _FR signal of the vehicle body detected by the sprung vertical G sensor 1 _FR
Extracting a resonance frequency band component signal of high frequency vibrations, which by obtaining the absolute value processing and averaging processing judgment signal S _B, it is possible to indirectly detect the operating state of the anti-skid control.

FIG. 19 shows sprung vertical acceleration signals (front right FR, rear right RR) (a), brake fluid pressure (front right FR / RH, front left FR / L).
H, rear right RR) (b), and a time chart showing actual vehicle data in the anti-skid control operating state (c),
As shown in this figure, the operation state of the anti-skid control is O
When in the N state, the brake pipe vibrates at a high frequency due to a sudden change in the brake fluid pressure, and this vibration is transmitted to the vehicle body, and the vibration of the vehicle body is detected as a sprung vertical acceleration signal. It can be seen that the frequency of the sprung vertical acceleration signal is extremely changed as compared with.

Next, the one of the damping force characteristic control operation in the damping force characteristic control for the control unit 4, the braking control by the normal operation control and braking control unit by the basic control unit described above by the determination signal S _B The content of the switching control and the content of the braking control will be described based on the flowchart of FIG. 20 and the time chart of FIG.

First, in the flowchart of FIG.
In step 201, it is determined whether or not the signal from the brake switch 5 is ON. If YES (during operation of the brake pedal), the process proceeds to step 202.

[0042] determines whether In step 202, a determination signal S _B exceeds the predetermined determination threshold value S _T,
If YES (S _B > S _T ), since the anti-skid control is being operated, the braking control is performed in step 203.
To move the shock absorber SA to the compression side hard area SH.
On the side, up to a damping force characteristic of the compression phase position P _{C-ma x}
(See FIG. 13).

[0043] The determined at step 201 NO and (in the brake pedal not operated), or, when in the step 202 is judged NO (S _B ≦ S _T), in a state where braking is not performed Therefore, the process proceeds to step 204 for performing normal control, and normal control (skyhook control) is performed by the normal control unit. Thus, one control flow is completed, and thereafter, the above control flow is repeated.

That is, in the braking control, FIG.
As shown in FIG. 13 (c), the shock absorber SA is fixedly controlled to the maximum position PC _-max on the compression stroke side in the compression-side hard region SH, so that the compression stroke is controlled as shown in FIG. The damping force characteristic on the side is a hard characteristic, and the extension stroke side, which is the reverse stroke, has a soft characteristic (extension stroke side damping force <compression stroke side damping force). As shown, the center of the wheel load fluctuation is shifted in the increasing direction to increase the frictional force between the tire and the road surface (grip force of the tire), so that the braking performance is improved. As a result, the solid line in FIG. As shown in the figure, the conventional damper CONV (extension side damping force>
The braking distance can be shortened as compared with the case of the compression stroke side damping force). FIG. 24 is a diagram showing the stopping distance characteristics with respect to the input frequency. In comparison with the case of the conventional damper CONV (extending stroke side damping force> pressure stroke side damping force) shown by a polygonal line in the figure, a diamond-shaped point is shown. As shown by the polygonal line, the stopping distance can be shortened in a frequency band (input frequency: 1 to 8 Hz) of a sprung behavior that greatly affects wheel load fluctuation during braking.

As described above, in the anti-skid control operating state detecting device according to the first embodiment of the present invention,
The following effects can be obtained. When the vehicle is not braking, the ride performance and steering stability of the vehicle are ensured by controlling the damping force characteristics of the shock absorber SA based on the skyhook control theory. Can be shortened.

Since the anti-skid control operation state can be indirectly detected from the sprung vertical acceleration G signal of the vehicle, the anti-skid control control unit 6
Omission of signal wiring from the control units 4 and 6
Can be simplified, thereby improving vehicle mountability and reducing costs. Particularly, in a vehicle equipped with an anti-skid control device as standard, even if an electronically controlled suspension system that uses the anti-skid control operation state signal as one of the damping force characteristic control signals is optionally set, the anti-skid control Since the unit 6 can be installed independently without changing the structure of the unit 6 or adding a signal wiring from the control unit 6 for anti-skid control, the cost for setting options can be minimized.

(Second Embodiment of the Invention) The anti-skid control operation state detecting device of the second embodiment of the present invention is different from the anti-skid control operation state detecting device of the first embodiment of the present invention in the vertical direction of the vehicle. Since the place where the behavior is detected is different, and the other points are almost the same as those of the vehicle suspension system according to the first embodiment of the present invention, only the differences will be described.

FIG. 2 shows a vehicle suspension system having an anti-skid control operating state detecting device according to a second embodiment of the present invention.
As shown in FIG. 5, the unsprung vertical acceleration G (Ga _FL , Ga _FR , Ga _RL , Ga _RR ) is provided at each wheel position on the unsprung side of the vehicle in place of the sprung vertical G sensor 1. (Hereinafter, referred to as unsprung vertical G sensor) 8 (8 _FL , 8 _FR , 8 _RL , 8 _RR ) is provided.

FIG. 26 is a system block diagram. In the control unit 4 for controlling the damping force characteristics, the unsprung vertical sensors G ( _8FL , _8FR , _8RL , _8RR ) detected by the unsprung vertical sensors 8 are used. Directional acceleration Ga (Ga _FL , Ga _FR , G
A signal processing circuit for estimating the sprung vertical acceleration G (G _FL , G _FR , G _RL , G _RR ) at each wheel position from the a _RL , Ga _RR ) signal is provided.

That is, in this signal processing circuit, as shown in the block diagram of FIG. 27, each unsprung vertical G sensor uses a transfer function from the unsprung vertical acceleration to the sprung vertical acceleration (formula (6)). 8 (8 _FL , 8 _FR , 8 _RL , 8 _RR ) detected unsprung vertical acceleration Ga (Ga _FL , Ga _FR , Ga _RL ,
Ga _RR ) signal, the sprung vertical acceleration G (G _FL ,
G _FR , G _RL , G _RR ) signals are estimated. Then, the sprung vertical acceleration G (G _FL , G
_FR , G _RL , G _RR ) signals and the respective shock absorbers SA (SA _FL , S _FL) as in the first embodiment of the present invention.
A _FR , SA _RL , and SA _RR ) are controlled.

[0051] _{G (S) = (c ·} s + k) / (m · s 2 + c · s + k) ········ (6) Next, among the control operation of the damping force characteristic control for the control unit 4 , a configuration of a signal processing circuit for obtaining a determination signal S _B for detecting the anti-skid control operation state, FIG. 2
8 will be described.

Firstly, generating the C1, the unsprung vertical acceleration Ga _FR signal detected by the right front unsprung vertical G sensor, by treatment with a band-pass filter BPF cutoff frequency 100 Hz, the vehicle during anti-skid control operation Extract the resonance frequency band component signal of the high frequency vibration
In the following C2, the absolute value of the resonance frequency band component signal of the high-frequency vibration is obtained. In the following C3, the absolute value is set to 2 Hz.
Obtaining a determination signal S _B, averaged by treatment with a low-pass filter LPF.

[0053] That is, as a basis signal for generating a determination signal S _B to determine the anti-skid control operation state, instead of the sprung vertical acceleration G signal, point to use a unsprung vertical acceleration Ga signals The other processing method is the same as that of the first embodiment of the invention except for the difference.

Therefore, in the anti-skid control operation state detecting device according to the second embodiment of the present invention, the same effect as in the first embodiment of the present invention can be obtained.

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 control of switching the damping force characteristic control of the shock absorber from the normal control to the braking control is performed based on the detection of the anti-skid control operation state. Is optional, and an alarm or a lamp indicating the anti-skid control operation state may be displayed.

[0057] Further, in the embodiment of the invention, was used vertical acceleration signal detected by the sprung installed at right front position vertical G sensors 1 _FR or unsprung mass vertical G sensor 8 _FR, other wheel position It is also possible to use the acceleration signal detected by the upper and lower G sensors installed in the camera. However, it is desirable to use the detection signals of the upper and lower G sensors installed near the brake pipe as much as possible.

In the embodiment of the present invention, the operation state of the anti-skid control is confirmed by the brake switch 5, but this can be omitted.

In the embodiment of the present invention, the case where the vertical acceleration signal is used as the vertical motion signal in the vehicle for obtaining the judgment signal has been described, but the sprung or unsprung vertical speed signal is used. be able to.

In the embodiment of the present invention, when the damping force characteristic on one of the extension stroke and the compression stroke is variably controlled as the shock absorber, the damping force characteristic on the reverse stroke side becomes a soft characteristic. Although a structure having a fixed structure is used, the present invention can be applied to a structure having a structure in which the damping force characteristics of both the expansion stroke and the compression stroke are simultaneously changed.

In the embodiment of the present invention, the soft region SS is controlled only when the sprung vertical speed signal is 0. However, a predetermined dead zone centered on 0 is provided and the spring is controlled within this dead zone. By maintaining the damping force characteristic in the soft region SS while the up-down speed is changing, control hunting can be prevented.

[0062]

As described above, in the anti-skid control operating state detecting device of the present invention, as described above, the vertical behavior detecting means for detecting the vertical behavior of the vehicle,
Judgment signal forming means for extracting a resonance frequency band component of high-frequency vibration generated in the vehicle at the time of anti-skid control operation as a judgment signal from the vertical movement signal of the vehicle detected by the vertical movement detection means; Anti-skid control operation state determining means for determining that the anti-skid control is activated when the determination signal extracted in step (b) exceeds a predetermined threshold value. Therefore, it is possible to omit the signal wiring and simplify the controller, thereby obtaining the effect of improving the in-vehicle property and reducing the cost.

Further, for example, in a vehicle equipped with an anti-skid control device as standard, an electronically controlled suspension system using an anti-skid control operating state signal as one of suspension damping force characteristic control signals is optionally set. Can be installed independently without changing the structure of the control unit for anti-skid control or adding signal wiring from the control unit for anti-skid control, minimizing the cost of setting options. become.

[Brief description of the drawings]

FIG. 1 is a drawing corresponding to a claim showing an anti-skid control operation state detecting device of the present invention.

FIG. 2 is a configuration explanatory view showing a vehicle suspension device provided with the anti-skid control operation state detection device according to the first embodiment of the present invention.

FIG. 3 is a system block diagram illustrating a vehicle suspension device including the anti-skid control operation state detection device according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a shock absorber applied to a vehicle suspension equipped with the anti-skid control operation state detecting device according to the first embodiment of the present invention.

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.

FIG. 8 is a perspective view of the shock absorber shown in FIG.
It is -K sectional drawing.

FIG. 9 is a perspective view of the shock absorber shown in FIG.
It is an L sectional view and MM sectional view.

FIG. 10 is a sectional view taken along line NN of FIG. 5 showing a main part of the shock absorber.

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 first signal processing for obtaining a sprung vertical speed and a sprung unsprung relative speed signal from a sprung vertical acceleration in a vehicle suspension including the anti-skid control operating state detecting device according to the first embodiment of the present invention; It is a block diagram showing a circuit.

FIG. 15 is a diagram showing a gain characteristic (a) and a phase characteristic (b) of the sprung vertical velocity signal converted by using the phase lag compensation equation.

FIG. 16 is a flowchart illustrating a normal control operation of the damping force characteristic of the control unit in the vehicle suspension including the anti-skid control operation state detecting device according to the first embodiment of the present invention.

FIG. 17 is a time chart showing a normal control operation of the damping force characteristic of the control unit in the vehicle suspension including the anti-skid control operation state detecting device according to the first embodiment of the present invention.

FIG. 18 is a diagram illustrating a second example of determining the determination signal in the anti-skid control operation state detecting device according to the first embodiment of the present invention.
FIG. 3 is a block diagram illustrating a signal processing circuit.

FIG. 19 is a time chart showing actual vehicle data in a vehicle suspension provided with the anti-skid control operation state detecting device according to the first embodiment of the present invention.

FIG. 20 shows the contents of switching control between normal control by the normal control unit and braking control by the braking control unit in the vehicle suspension equipped with the anti-skid control operating state detecting device of the first embodiment of the present invention. It is a flowchart shown.

FIG. 21 shows the contents of switching control between normal control by the normal control unit and braking control by the braking control unit in the vehicle suspension equipped with the anti-skid control operation state detecting device according to the first embodiment of the present invention. It is a time chart shown.

FIG. 22 is a time chart illustrating wheel load characteristics in a vehicle suspension including the anti-skid control operation state detecting device according to the first embodiment of the present invention.

FIG. 23 is a time chart illustrating a braking distance characteristic of the vehicle suspension including the anti-skid control operation state detecting device according to the first embodiment of the present invention.

FIG. 24 is a characteristic diagram of a stopping distance with respect to an input frequency in a vehicle suspension including the anti-skid control operating state detecting device according to the first embodiment of the present invention.

FIG. 25 is a configuration explanatory view showing a vehicle suspension device provided with an anti-skid control operation state detection device according to a second embodiment of the present invention.

FIG. 26 is a system block diagram illustrating a vehicle suspension system including an anti-skid control operation state detection device according to a second embodiment of the present invention.

FIG. 27 is a block diagram illustrating a signal processing circuit that estimates a sprung vertical acceleration from a unsprung vertical acceleration in a vehicle suspension including the anti-skid control operating state detecting device according to the second embodiment of the present invention.

FIG. 28 is a block diagram illustrating a signal processing circuit for obtaining a determination signal in the anti-skid control operation state detection device according to the second embodiment of the present invention.

[Explanation of symbols]

 a vertical movement detecting means b determination signal forming means c anti-skid control operating state determining means

Claims (1)

[Claims] 1. A vertical behavior detecting means for detecting a vertical behavior of a vehicle, and a resonance of a high frequency vibration generated in the vehicle when an anti-skid control is activated from a vertical behavior signal of the vehicle detected by the vertical behavior detecting means. A judgment signal forming means for extracting a frequency band component as a judgment signal; and an anti-skid control operation for judging an anti-skid control operation when the judgment signal extracted by the judgment signal forming means exceeds a predetermined threshold value. An anti-skid control operation state detection device, comprising: a state determination unit.