JPH11190628A - Detection device for inclination angle of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an accurate detection of an inclination angle of a vehicle by fixing it to be a specified value when a vehicle behavior detected by a vehicle behavior detection means exceeds a specified value. SOLUTION: Vehicle behavior detection means comprises a sprung upward/ downward acceleration sensor (upward/downward G sensor) 1FL, 1FR, 1RL, 1RR, a forward/rearward acceleration/deceleration speed sensor (forward/rearward G sensor) 2, an a lateral acceleration sensor (lateral G sensor) 8. Acceleration signals from the sensors 1FL, 1FR, 1RL, 1RR, 2, 8 are input to a control unit 4 serving as computation means to perform operation of an inclination of a vehicle. When each signal value exceeds a specified value, operation of computation is carried out with the inclination thereof fixed. Accordingly, it is possible to prevent the detection of inclination angle exceeding a limit inclination angle of the vehicle, leading to an accurate measurement of inclination angle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle inclination angle detecting device for detecting an inclination angle of a vehicle generated according to a running state of the vehicle.

[0002]

2. Description of the Related Art Conventionally, a vehicle inclination angle detecting device for detecting an inclination angle of a vehicle generated according to a running state of the vehicle includes:
For example, a "vehicle body inclination angle calculating device" described in Japanese Patent Application Laid-Open No. H8-2234 is known. This conventional vehicle inclination angle detecting device detects acceleration (longitudinal acceleration, lateral acceleration) acting on the vehicle body detected by acceleration detecting means (longitudinal acceleration sensor, lateral acceleration sensor) and wheel vertical rigidity detecting means. The configuration is such that the inclination angle (pitch angle, roll angle) of the vehicle body is calculated based on the vertical rigidity of the wheels.

[0003]

However, the conventional apparatus has the following problems since it is configured as described above. That is, since the pitch angle and the roll angle are obtained by calculating from the detection values of the longitudinal acceleration sensor and the lateral acceleration sensor, when the detection values of the longitudinal acceleration and the lateral acceleration increase, the calculation result becomes The pitch angle and roll angle will also increase,
Since the range of expansion and contraction of the shock absorber is limited, the actual pitch angle and roll angle of the vehicle never exceed a certain fixed angle, and therefore, it is not possible to accurately detect the pitch angle and the roll angle. .

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a vehicle inclination angle detecting device capable of accurately detecting the inclination angle of a vehicle. .

[0005]

In order to achieve the above object, a vehicle inclination angle detecting apparatus according to a first aspect of the present invention detects a vehicle behavior as shown in a claim correspondence diagram of FIG. A vehicle inclination angle calculating device that calculates a vehicle inclination angle from the vehicle behavior detected by the vehicle behavior detecting means a;
The vehicle inclination angle calculating means b is provided with the vehicle behavior detecting means a.
When the vehicle behavior detected in step (1) is equal to or more than a predetermined value, the means is configured to fix the inclination angle of the vehicle to a predetermined value. According to a second aspect of the present invention, in the vehicle tilt angle detecting device according to the first aspect, the vehicle behavior detecting means a for detecting the behavior of the vehicle includes a longitudinal acceleration detecting means for detecting a longitudinal acceleration of the vehicle. The inclination angle calculating means b
The means comprises a vehicle pitch angle calculating means for calculating the pitch angle of the vehicle. According to a third aspect of the present invention, in the vehicle tilt angle detecting device according to the first aspect, the vehicle behavior detecting means a for detecting the behavior of the vehicle includes a lateral acceleration detecting means for detecting a lateral acceleration of the vehicle. The inclination angle calculating means b is a means constituted by a vehicle roll angle calculating means for calculating a roll angle of the vehicle. According to a fourth aspect of the present invention, in the vehicle inclination angle detecting device according to the first aspect, the vehicle behavior detecting means for detecting the behavior of the vehicle includes a longitudinal acceleration detecting means for detecting a longitudinal acceleration of the vehicle and a lateral acceleration of the vehicle. Means for detecting a lateral acceleration detecting means for detecting the vehicle, wherein the vehicle inclination angle calculating means comprises a vehicle pitch angle calculating means for calculating a pitch angle of the vehicle and a vehicle roll angle calculating means for calculating a roll angle of the vehicle. And According to a fifth aspect of the present invention, there is provided a vehicle inclination angle detecting device according to any one of the first to fourth aspects, wherein the longitudinal acceleration detecting means or the lateral acceleration detecting means constituting the vehicle behavior detecting means a is detected by a wheel speed detecting means. Means are configured to detect the longitudinal acceleration of the vehicle or the lateral acceleration of the vehicle from the speed.

[0006]

In the vehicle inclination angle detecting device according to the first aspect of the present invention, the vehicle inclination angle calculating means b calculates the vehicle inclination angle from the vehicle behavior detected by the vehicle behavior detecting means a. When the vehicle behavior detected by the vehicle behavior detecting means a is equal to or greater than a predetermined value, a process for fixing the inclination angle of the vehicle to a predetermined value is performed. As a result, it is possible to prevent the detection of the inclination angle exceeding the actual inclination angle of the vehicle, so that the inclination angle of the vehicle can be accurately detected. Further, in the vehicle inclination angle detection device according to the second aspect, since the pitch angle of the vehicle generated at the time of vehicle braking can be accurately detected, the suspension and the anti-skid control device can be accurately controlled. Further, in the vehicle inclination angle detecting device according to the third aspect, since the roll angle of the vehicle generated during the steering of the vehicle can be accurately detected, the suspension and the anti-skid control device can be accurately controlled. Further, in the vehicle inclination angle detecting device according to the fourth aspect, since the pitch angle and the roll angle of the vehicle generated during braking and steering of the vehicle can be accurately detected, the suspension and the anti-skid control device can be accurately controlled. can do. In the vehicle inclination angle detecting device according to the fifth aspect, it is not necessary to separately provide an acceleration sensor in a vehicle equipped with an anti-skid control device.

[0007]

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 a perspective view showing a cab portion in a configuration explanatory view showing an example in which the vehicle inclination angle detecting device of FIG. 1 is applied to a cab inclination angle detecting device of a cab-over type vehicle. As shown in FIG. And four shock absorbers SA _FL , SA _FR , S
A _RL , SA _RR (In describing the shock absorber, when these four are collectively referred to, and when describing the common configuration thereof, they are simply indicated as SA. The lower right symbol indicates the installation position. _FL indicates front left, _FR indicates front right, _RL indicates rear left, and _RR indicates rear right.) In the vicinity of the shock absorber SA, air springs 36 are provided between the cab 5 and the chassis 6, respectively. Note that the shock absorber SA and the air spring 36 are not shown on the right side of the right and left sides.

[0008] Each of the shock absorbers SA _FL and S _FL
A _FR, SA _RL, the cab 5 of the vicinity of the SA _RR, cab (sprung) side of the vertical acceleration GUD (GUD _FL, GU
A sprung vertical acceleration sensor (hereinafter referred to as a vertical G sensor) 1 _FL , 1 _FR , 1 _RL , 1 _RR that detects D _FR , GUD _RL , GUD _RR ) (positive value upward and negative value downward) Provided,
The upper and lower G sensors 1 are located near the driver's seat.
(1 _FL , 1 _FR , 1 _RL , 1 _RR ), and the pulse motor 3 of each shock absorber SA based on signals from the longitudinal acceleration sensor 2 and the lateral acceleration sensor 8 described later.
Is provided with a control unit 4 for outputting a drive control signal.

FIG. 3 is a side view showing the entire cab-over type vehicle. As shown in FIG. 3, a chassis 6 at an intermediate position between a front wheel and a rear wheel has a longitudinal acceleration / deceleration GFB ( A front-rear acceleration / deceleration sensor (hereinafter referred to as a front-rear G sensor) 2 for detecting a positive value in the acceleration direction and a negative value in the deceleration direction is provided, and the front left and right shock absorbers SA _FL and SA _FR are also provided. A chassis 6 at a nearby position is provided with a lateral acceleration sensor (hereinafter referred to as a lateral G sensor) 8 for detecting a lateral acceleration GLR of the vehicle.

[0010] that shows the above structure a system block diagram of FIG. 4, the control unit 4 includes an interface circuit 4a, CPU 4b, a drive circuit 4c, the interface circuit 4a, each vertical G sensors 1 _FL , 1 _FR , 1 _RL , 1 _RR from cab (spring up) side vertical acceleration GUD (GUD _FL , GUD _FR , GUD _RL , GUD _RR )
Signal, a longitudinal acceleration GFB signal from the longitudinal G sensor 2,
Further, a lateral acceleration GLR signal from the lateral G sensor 8 is input.

As shown in FIG. 15, a cab (spring) detected by the upper and lower G sensors 1 (1 _FL , 1 _FR , 1 _RL , 1 _RR ) according to the inclination of the cab 5 in the pitch direction is provided in the interface circuit 4a. Vertical acceleration GUD (G
_{UD FL, GUD FR, GUD RL} , GUD RR) signal in the front-rear direction acceleration component GudFB (GudFB _FL contained, GudFB _FR, GudF
B _RL , GudFB _RR ) and the longitudinal acceleration / deceleration components GudFB (GudFB _FL , GudFB _FR , GudFB _RL , GudF R).
B _RR ), a signal processing circuit for _obtaining a vertical acceleration G (G _FL , G _FR , G _RL , G _RR ) signal of the cab 5 in the absolute space in which the cab 5 is rolled in the absolute space, as shown in FIG. The vertical G sensor 1 (1 _FL , 1 _FR , 1
_RL , 1 _RR ), the lateral acceleration components GudLR (GudLR _FL , GudL) included in the vertical acceleration GUD (GUD _FL , GUD _FR , GUD _RL , GUD _RR ) signal on the cab (spring-up) side detected.
R _FR , GudLR _RL , GudLR _RR ) and the lateral acceleration / deceleration components GudLR (GudLR _FL , GudLR _FR , GudLR _RL ,
Cab 5 in absolute space where GudLR _RR was canceled
Signal processing circuit for _obtaining the vertical acceleration G (G _FL , G _FR , G _RL , G _RR ) signal of the cab 5 and the vertical acceleration G (G _FL , G _FR , G _RL , G _RR ) of the cab 5 in the absolute space. , Cab 5 at each shock absorber SA position (spring up)
And a signal processing circuit for determining the relative velocity (Δx−Δx ₀ ) between the cab 5 and the chassis 6 (between the sprung and unsprung). The details of these signal processing circuits will be described later.

FIG. 5 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 piston rod 7 and a bump rubber 37 are provided.

FIG. 6 is an enlarged sectional view showing a part of the piston 31. As shown in FIG. 6, 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. 5). 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 leading to the lower chamber B, and a bypass reaching 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. 7 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. 8, the KK section, the LL section, the MM section, and the NN section in FIG. 6 when the adjuster 40 is arranged at the position of, respectively. 9, 10 and 11, and the damping force characteristics at each position are shown in FIGS. 12, 13 and 14.

Next, during the control operation of the control unit 4, the cab (spring-up) side detected by the upper and lower G sensors 1 ( _1FL , _1FR , _1RL , _1RR ) due to the inclination of the cab 5 in the pitch direction. Vertical acceleration GUD (GUD _FL , GUD _FR ,
The longitudinal acceleration / deceleration components GudFB (GudFB _FL , GudFB _FR , GudFB _RL , GudFB _RR ) included in the GUD _RL and GUD _RR signals are obtained, and the longitudinal acceleration / deceleration components GudFB (GudFB) are obtained.
_FL , GudFB _FR , GudFB _RL , GudFB _RR ) cancel the vertical acceleration G (G _FL ,
The details of the signal processing circuit for _{obtaining the} (G _FR , G _RL , G _RR ) signal will be described based on the block diagram of FIG. 15 and the operation explanatory diagram of FIG.

First, in the block diagram of FIG.
, The longitudinal acceleration / deceleration G detected by the longitudinal G sensor 2
From the FB signal, the pitch angle θp of the cab 5 at the time of acceleration and deceleration of the vehicle is obtained based on the following equations (1) and (2) (see FIG. 17).

During acceleration θp = Kf · GFB−Kf · GFBmin-f (1) where GFBmin−f <GFB and when GFB> GFBmax−f, θp = θpmax− f Kf is a constant at the time of acceleration, GFBmin-f is a dead zone on the acceleration side, GFBmax-f is the maximum value of the acceleration GFB signal, θpmax-f
Is the maximum value of the pitch angle θp in the scat direction.

That is, the maximum value θpmax-f of the pitch angle in the scat direction is set to the maximum value of the pitch angle θp in the scat direction of the cab 5 calculated in advance from the limit value of the expansion and contraction range of each shock absorber SA and the like. , The acceleration G
The maximum value GFBmax-f of the FB signal is set to an acceleration value at which the pitch angle θp of the cab 5 in the scat direction becomes the previously calculated maximum value θpmax-f.

When decelerating, θp = Kb · GFB−Kb · GFBmin-b (2) where GFBmin-b <GFB and when GFB> GFBmax-b, θp = θpmax- b Kb is a constant at the time of acceleration, GFBmin-b is the dead zone on the deceleration side, GFBmax-b is the maximum value of the deceleration GFB signal, θpmax-b
Is the maximum value of the pitch angle θp in the north dive direction. That is, the maximum value θpma of the nose dive direction pitch angle θp
x-b is set to the maximum value of the nose diving direction pitch angle θp of the cab 5 calculated in advance from the limit value of the expansion and contraction range of each shock absorber SA, and the deceleration GFB
The maximum value GFBmax-b of the signal is the maximum value θpmax-b of the nose dive direction pitch angle θp of the cab 5 calculated in advance.
Is set to the deceleration value when

In the following C2, the vertical G sensor 1 (1 _FL , 1 _FL ) is tilted in the pitch direction of the cab 5 based on the following equation (3).
_FR, 1 _RL, 1 _RR) detected by the cab (vertical acceleration GUD of the sprung) side _{(GUD FL, GUD FR, GUD} RL, GUD RR)
The longitudinal acceleration / deceleration component GudFB (GudF
B _FL , GudFB _FR , GudFB _RL , GudFB _RR ) (FIG. 1)
6).

GudFB = GFB · sin θp ≒ GFB · θp (3) In the following C3, the upper and lower G sensors 1 (1
Cab detected on _FL , _1FR , _1RL , _1RR )
GUD _FL , GUD _FR , GUD _RL , G
UD _RR) wherein in the signal before and after the obtained by the C2 direction acceleration component _{GudFB (GudFB FL, GudFB FR,} GudFB RL, G
A vertical acceleration G (G _FL , G _FR , G _RL , G _RR ) signal of the cab 5 in the absolute space where udFB _RR is canceled is obtained (see FIG. 16).

G = GUD · (1 / cos θp) + | GudFB · cos θp | ≒ GUD + | GudFB | ≒ GUD + GFB · θp (4) Next, in the control operation of the control unit 4, the upper and lower G sensors 1 ( _1FL ,
1 _FR , 1 _RL , 1 _RR ) The vertical acceleration GUD (GUD _FL , GUD _FR , GUD _RL , GU) on the cab (spring) side detected by
D _RR ) signal contained in the lateral acceleration component GudLR (GudLR)
_FL , GudLR _FR , GudLR _RL , GudLR _RR )
The longitudinal acceleration / deceleration component GudLR (GudLR _FL , GudLR _FR ,
GudLR _RL , GudLR _RR ) cancels the vertical acceleration G (G _FL , G _FR , G _RL , G
_RR ) signal processing circuit for _{obtaining the} signal, and the vertical acceleration G (G _FL , G _FR , G _RL , G _RR ) of the cab 5 in the absolute space.
From above, the sprung vertical speed Δx at each shock absorber SA position and the sprung-unsprung relative speed (Δx−Δx
₀ ) will be described with reference to the block diagram of FIG. 18 and the operation explanatory diagram of FIG.

First, in the block diagram of FIG.
Then, from the lateral acceleration GLR signal detected by the lateral G sensor 8, the roll angles θr of the cab 5 when the vehicle rolls to the right and to the left are calculated based on the following equations (5) and (6). (See FIG. 20).

When turning right θr = Kr · GLR−Kr · GLRmin-r (5) where GLRmin-r <GLR, and when GLR> GLRmax-r, θr = θrmax-r where Kr is a constant when turning right, GLRmin-r is a dead zone on the right turning side, GLRmax-r is the maximum value of the lateral acceleration GLR signal, θ
rmax-r is the maximum value of the rightward roll angle θr. That is,
The maximum value of the rightward roll angle θrmax-r is set to the maximum value of the rightward roll angle θr of the cab 5 calculated in advance from the limit value of the expansion and contraction range of each shock absorber SA and the lateral acceleration. GLR signal maximum value GLRmax-r
Is set to the lateral acceleration value when the rightward roll angle θr of the cab 5 reaches the previously calculated maximum value θrmax-r.

When turning left θr = Kl · GLR-Kl · GLRmin-l (6) where GLRmin-l <GLR and GLR> GLRmax-l, θr = θrmax Kl is a constant when turning left, GLRmin-1 is the dead zone on the left turn side, GLRmax-1 is the maximum value of the leftward roll speed GLR signal, and θrmax-1 is the maximum value of the leftward roll angle. That is, the maximum value of the leftward roll angle θrmax-1 is set to the maximum value of the leftward roll angle θr of the cab 5 calculated in advance from the limit value of the expansion and contraction range of each shock absorber SA and the like, and Maximum value GLRma of direction acceleration GLR signal
x-l is set to a lateral acceleration value when the leftward roll angle θr of the cab 5 reaches the previously calculated maximum value θrmax-1.

In D2, the upper and lower G sensors 1 (1 _FL , 1 _FL ) are determined by the inclination of the cab 5 in the roll direction based on the following equation (7).
_FR, 1 _RL, 1 _RR) detected by the cab (vertical acceleration GUD of the sprung) side _{(GUD FL, GUD FR, GUD} RL, GUD RR)
The lateral acceleration component GudLR (GudLR _FL , G
udLR _FR , GudFB _RL , GudFB _RR ) are obtained (see FIG. 18).

GudLR = GLR · sin θr ≒ GLR · θr (7) In the following D3, based on the following equation (8), the upper and lower G sensors 1 (1
Cab detected on _FL , _1FR , _1RL , _1RR )
GUD _FL , GUD _FR , GUD _RL , G
The lateral acceleration component GudLR (GudLR _FL , GudLR _FR , GudFB _RL , GudFB) determined in the above D2 included in the UD _RR signal.
_RR ) in the absolute space in which the vertical acceleration G (G _FL , G _FR , G _RS ) signal of the cab 5 in the absolute space is obtained (FIG. 1).
8).

G = GUD · (1 / cos θr) + | GudLR · cos θr | ≒ GUD + | GudLR | ≒ GUD + GLR · θr (8) Next, in the control operation of the control unit 4, the vertical acceleration G (G _FL ,
G _FR , G _RL , G _RR ), the vertical speed Δx of the cab 5 (spring) at each shock absorber SA position,
The configuration of a signal processing circuit for obtaining the relative speed (Δx−Δx ₀ ) between the cab 5 and the chassis 6 (between the sprung and the unsprung) will be described with reference to the block diagram of FIG.

First, in B1, a phase delay compensation equation is used,
The vertical acceleration G (G _FL , G _FR , G F, G 2) of the cab 5 in the absolute space at each shock absorber SA position obtained by the signal processing circuit of FIG. 15 and / or FIG.
G _RL , G _RR ) is converted into a vertical speed signal of each shock absorber SA position. The general expression of the phase delay compensation can be expressed by the following transfer function expression (9).

G _(S) = ((AS + 1) / (BS + 1)) (9) (A <B) Then, a frequency band (0.5 Hz to 3) required for damping force characteristic control.
Hz), it 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 (10 ) Is used.

G _(S) = (0.001 S + 1) / (10S + 1) × γ (10) where γ is a signal and gain characteristic when speed conversion is performed by integration (1 / S). And γ = 10 in the embodiment of the present invention. As a result, as shown in the solid line gain characteristics in FIG. 22A and the solid line phase characteristics in FIG. 22B, 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, a band-pass filter process for cutting off components other than the target frequency band to be controlled is performed. That is, the band-pass filter BPF includes a second-order high-pass filter HPF (0.8 Hz) and a second-order low-pass filter LPF (1.2 Hz). Direction speed Δx
(Δx _FL , Δx _FR , Δx _RL , Δx _RR ) signals are obtained.

On the other hand, in B3, as shown in the following equation (11),
Using the transfer function Gu _(S) from the vertical acceleration of the cab 5 in each absolute space to the relative speed between sprung and unsprung,
Vertical acceleration G of the cab 5 in each absolute space
From the (G _FL , G _FR , G _RL , G _RR ) signal, the relative speed (Δx−Δ) between the sprung and unsprung positions of each shock absorber SA is determined.
x ₀ ) [(Δx−Δx ₀ ) _FL , (Δx−Δx ₀ ) _FR ,
(Δx−Δx ₀ ) _RL , (Δx−Δx ₀ ) _RR ] signal is obtained. Gu _(S) =-ms / (cs + k) (11) where m is a sprung mass, c is a damping coefficient of the suspension, and k is a spring constant of the suspension.

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

In step 101, it is determined whether or not the sprung vertical speed Δx is a positive value. If YES, the routine proceeds to step 102, in which each shock absorber SA is controlled to the extension side hard area HS, and NO If so, step 103
Proceed to.

At step 103, it is determined whether or not the sprung vertical speed Δx is 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, Step 105 if any
Proceed to.

Step 105 is a processing step when NO is determined in steps 101 and 103, that is, when the value of the sprung vertical speed Δx is 0. In this case, each shock absorber SA To the soft area SS.

Next, the contents of the control operation of the damping force characteristic of the shock absorber SA in the control unit 4 will be described with reference to the time chart of FIG.

When the sprung vertical speed Δx changes as shown in this figure, as shown in the figure, when the value of the sprung vertical speed Δx is 0, the shock absorber S
A is controlled to the soft area SS.

Further, when the value of the sprung vertical speed Δx becomes a positive value, the expansion-side hard region HS is controlled to fix the compression-side damping force characteristic to the soft characteristic, while the expansion-side signal forming the control signal is controlled. Damping force characteristics (target damping force characteristic position P
_T ) is changed in proportion to the sprung vertical speed Δx based on the following equation (12). P _T = α · Δx · Ku (12) where α is a constant on the extension side, and Ku is a relative speed between the sprung and unsprung (Δx −Δx ₀ ).

When the value of the sprung vertical speed 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 constituting the control signal is controlled. force characteristic (target damping force characteristic position P _C)
Is changed in proportion to the sprung vertical speed Δx based on the following equation (13). P _C = β · Δx · Ku (13) where β is a pressure-side constant.

Next, among the damping force characteristic control operations of the 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 (the shock absorber SA). (The stroke is the pressure stroke side)
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 region, the compression stroke side, which is the stroke of the shock absorber SA at that time, has soft characteristics. Become.

The area b is the sprung vertical velocity Δx
Is a positive value (upward), and the sprung-unsprung relative speed (Δx−Δx ₀ ) is in a region where the value 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 sprung vertical speed Δx, and the stroke of the shock absorber is also the extension stroke. The extension stroke side, which is the stroke of the shock absorber SA at that time, has hardware characteristics proportional to the value of the sprung vertical speed Δx.

The area c is the sprung vertical velocity Δx
Is reversed from a positive value (upward) to a negative value (downward), but at this time, the sprung-unsprung relative speed (Δx−Δx ₀ ) is still a positive value (stroke of the shock absorber SA). In this case, the shock absorber SA is controlled to the compression-side hard region SH based on the direction of the sprung vertical velocity Δx. Therefore, in this region, The extension stroke side of the shock absorber SA has soft characteristics.

The area d is the sprung vertical velocity Δx
Is a negative value (downward), and the sprung-unsprung relative speed (Δx−Δx ₀ ) is an area where the value 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 in the compression-side hard region SH based on the direction of the sprung vertical speed Δx, and the stroke of the shock absorber is also the compression stroke. The pressure stroke side, which is the SA stroke, is the sprung vertical speed Δx.
Becomes a hard characteristic proportional to the value of.

As described above, according to the embodiment of the present invention, when the sprung vertical speed Δx and the sprung-unsprung relative speed (Δx−Δx ₀ ) have the same sign (region b, region d)
Is a skyhook control theory that controls the stroke side of the shock absorber SA at that time to a hard characteristic, and controls the stroke side of the shock absorber SA to a soft characteristic at a different sign (regions a and c). Is performed based only on the sprung vertical speed Δx signal. Further, in the embodiment of the present invention, the shock absorber S
At the time when the process of A is switched, that is, when shifting from the region a to the region b and from the region c to the region d (from the soft characteristic to the hard characteristic), the damping force characteristic position on the switching side is changed to the previous region a, c, the switching from the soft characteristic to the hard characteristic is performed without a time delay because the switching to the hardware characteristic has already been performed. As a result, a high control response can be obtained and the hardware characteristic can be switched from the soft characteristic to the hard characteristic. The switching to is performed without driving the pulse motor 3, thereby improving the durability of the pulse motor 3 and saving power consumption.

Next, in the damping force characteristic control operation of the shock absorber SA in the control unit 4, the cab (spring-up) side detected by the upper and lower G sensors 1 ( _1FL , _1FR , _1RL , _1RR ). Vertical acceleration GUD (GUD
The contents of the correction control of the _FL , GUD _FR , GUD _RL , and GUD _RR ) signals will be described with reference to FIGS.

(A) When the vehicle is traveling straight ahead at a constant speed When the vehicle is traveling straight ahead at a constant speed, the values of the pitch angle θp and the roll angle θr of the cab 5 are 0. According to (8), the upper and lower G sensor 1 (1 _FL , 1 _FL )
_FR, 1 _RL, 1 _RR) detected by the cab (vertical acceleration GUD of the sprung) side _{(GUD FL, GUD FR, GUD} RL, GUD RR)
The value of the signal is used as is.

(B) Vehicle acceleration / deceleration Vehicle (cab) generated by acceleration or deceleration of the vehicle
In the state where the vehicle is inclined in the front-rear (pitch) direction with respect to the traveling road surface due to the change in attitude (scut, dive) in the pitch direction of 5, the detection direction of the vertical G sensor 1 with respect to the traveling road surface is also inclined in the front-back direction with respect to the traveling road surface. When acceleration / deceleration in the front-rear direction due to acceleration or deceleration acts on the vehicle in this inclined state, the component force of the front-rear acceleration / deceleration acting in parallel to the traveling road surface is changed by the vertical G sensor 1.
, The vertical acceleration signal drifts by the component of the longitudinal acceleration / deceleration, thereby impairing the riding comfort and steering stability of the vehicle.

However, in the embodiment of the present invention, the value of the longitudinal acceleration / deceleration GFB signal detected by the longitudinal G sensor 2 due to the acceleration / deceleration of the vehicle is adjusted to a predetermined dead zone (the acceleration dead zone G).
When FBmin-f and the deceleration side dead zone GFBmin-b) are exceeded, the pitch angle θp of the cab 5 is detected by the equations (1) and (2), and the pitch direction inclination of the cab 5 is calculated by the equation (4). the vertical G sensor _{1 (1 FL, 1 FR,} 1 RL, 1 RR) detected cab (sprung) at the side of the vertical acceleration GUD
_{(GUD FL, GUD FR, GUD} RL, GUD RR) signal in the front-rear direction acceleration component GudFB (GudFB _FL contained, GudFB _FR, Gud
FB _RL , GudFB _RR ), the vertical acceleration G (G _FL , G _FR , G _RL , G _RR ) of the cab 5 in the absolute space in which the absolute space is canceled.
A signal is required.

Therefore, even when the vehicle is accelerated or decelerated, the drift of the sprung vertical acceleration signal is prevented, whereby the damping force characteristic control of the shock absorber SA is performed under substantially the same conditions as when the vehicle is traveling straight at a constant speed. become.

(C) Turning of the vehicle Even when the vehicle (cab) 5 is tilted in the lateral direction with respect to the running road surface due to the lateral attitude change (roll) of the vehicle (cab) 5 generated during the turning of the vehicle, the vehicle can be moved up and down with respect to the running road surface. Since the detection direction of the G sensor 1 is also inclined in the lateral direction with respect to the traveling road surface, the same problem as the above (b) occurs, which results in impairing the riding comfort and steering stability of the vehicle.

However, in the embodiment of the present invention, the value of the lateral acceleration / deceleration GLR signal detected by the lateral G sensor 8 due to the turning of the vehicle is set to a predetermined dead zone (right turning side dead zone GLRmi).
Beyond the range of n-r, left turn dead zone GLRmin-1),
Formula (5), (6) the roll angle θr of the cab 5 is detected by, according to the equation (8), and down by the roll direction inclination of the cab 5 G sensor _{1 (1 FL, 1 FR,} 1 RL, 1 RR ) The vertical acceleration GUD (GUD
_FL , GUD _FR , GUD _RL , GUD _RR ) The lateral acceleration / deceleration components GudLR (GudLR _FL , GudRL _FR , GudLR _RL , G
The vertical acceleration G (G _FL , G _FR , G _RL , G _RR ) signal of the cab 5 in the absolute space where udLR _RR is canceled is obtained.

Therefore, the drift of the sprung vertical acceleration signal is prevented even when the vehicle is turning, whereby the damping force characteristic control of the shock absorber SA is performed under substantially the same conditions as when the vehicle is traveling straight at a constant speed. Become.

As described above, the value of the longitudinal acceleration / deceleration GFB signal detected by the longitudinal G sensor 2 due to the acceleration / deceleration of the vehicle is a predetermined dead zone (acceleration-side dead zone GFBmin-f, deceleration-side dead zone GFBmin-b). , Or the lateral acceleration / deceleration G detected by the lateral G sensor 8 due to the turning of the vehicle.
When the value of the LR signal is within a predetermined dead band (right turning side dead band GLRmin-
r, when it is within the range of GLRmin-1),
Vertical acceleration GUD (GUD _FL , UD) on the cab (spring-side) side detected by the vertical G sensor 1 (1 _FL , 1 _FR , 1 _RL , 1 _RR )
GUD _FR , GUD _RL , and GUD _RR ) signals are not corrected (see FIGS. 18 and 20).

This is because the structure of the suspension is
It has a predetermined frictional resistance and generates at least a predetermined damping force in the shock absorber SA. In particular, in a suspension having an anti-suscut, anti-dive, and anti-roll control mechanism, a certain range of acceleration is Since the inclination of the cab 5 does not occur, the correction control is not performed for the detected acceleration within the range, so that a more accurate control signal can be obtained and the damping force characteristic control effect can be enhanced.

As described above, the value of the longitudinal acceleration / deceleration GFB signal detected by the longitudinal G sensor 2 due to the acceleration / deceleration of the vehicle is the maximum value calculated in advance from the limit value of the expansion / contraction range of each shock absorber SA. Value (maximum acceleration value GFBmax-
f, when the deceleration side maximum value GFBmax-b) is exceeded or the value of the lateral acceleration / deceleration GLR signal detected by the lateral G sensor 8 due to the turning of the vehicle is determined from the limit value of the expansion / contraction range of each shock absorber SA, etc. When the maximum value exceeds a pre-calculated maximum value (right-turning-side maximum value GLRmax-r, left-turning-side maximum value GLRmax-1), the pitch angle θp or the roll angle θr is changed to the pitch angle θp.
Are fixed to the maximum values (θpmax-f, θpmax-b) or the maximum values (θrmax-r, θrmax-1) of the roll angle θr, respectively, and processing is performed so that no more values are detected ( 18 and 20).

This is because the actual range of the pitch angle θ in the vehicle is limited because the range of expansion and contraction of the shock absorber is limited.
p and the roll angle θr do not exceed a certain fixed angle. Therefore, when each of the above-mentioned maximum values is exceeded, by fixing to the maximum value corresponding to the detected value at that time,
The detection of a pitch angle and a roll angle that are far from reality is prevented, whereby a more accurate control signal can be obtained and the damping force characteristic control effect can be enhanced.

As described above, the vehicle inclination angle detecting device according to the first embodiment of the present invention has an effect that the inclination angle of the vehicle can be accurately detected from the detected acceleration value of the vehicle. can get.

Further, in the cab suspension control device to which the vehicle inclination angle detecting device according to the first embodiment of the present invention is applied, the inclination and the longitudinal acceleration / deceleration or lateral acceleration of the cab 5 generated when the vehicle accelerates / decelerates and turns. Therefore, it is possible to prevent the controllability of the damping force characteristic of the shock absorber SA from deteriorating, thereby improving the ride comfort and the steering stability of the vehicle.

Further, since the longitudinal G sensor 2 and the lateral G sensor 8 are provided on the side of the chassis 6 where inclination due to longitudinal acceleration / deceleration and lateral acceleration of the vehicle is small, errors in detected acceleration due to inclination of the sensor are extremely small. Therefore, an effect that control accuracy can be improved can be obtained. (Embodiment 2) Next, a vehicle inclination angle detection apparatus according to Embodiment 2 of the invention will be described. Embodiment 2 of the present invention shows an embodiment in which the vehicle inclination angle detecting device is applied to a vehicle suspension device in a normal vehicle. In the description of the second embodiment of the present invention, the same components as those in the first embodiment of the present invention are denoted by the same reference numerals, and the description thereof will be omitted. Only the differences will be described.

FIG. 27 is a structural explanatory view showing a vehicle suspension system to which the vehicle inclination angle detecting device according to the second embodiment of the present invention is applied. As shown in FIG. Interposed, four shock absorbers SA _FL , SA
_FR , SA _RL and SA _RR are provided. Further, the vehicle body in the vicinity of each of the shock absorbers SA _FL , SA _FR , SA _RL , and SA _RR is provided with a sprung vertical acceleration GUD (GUD _FL , GUD _FL) .
_{UD FR, GUD RL, GUD RR} ) ( positive value upward, negative value) sprung mass vertical acceleration sensor (hereinafter for detecting the downward vertical referred G _{sensor) 1 FL, 1 FR, 1} RL, 1 RR is Provided,
Further, the vehicle body includes a longitudinal acceleration / deceleration sensor (hereinafter, referred to as a longitudinal G sensor) 2 for detecting the longitudinal acceleration / deceleration GFB (a positive value in the acceleration direction and a negative value in the deceleration direction) of the vehicle. A lateral acceleration sensor (hereinafter, referred to as a lateral G sensor) 8 for detecting the lateral acceleration GLR is provided, and the upper and lower G sensors 1 ( _1FL , _1FR , _1FR , 1 _RL , 1 _RR ), a control unit 4 that outputs a drive control signal to the pulse motor 3 of each shock absorber SA based on signals from the longitudinal acceleration sensor 2 and the lateral acceleration sensor 8.

As in the first embodiment of the present invention, the upper and lower G sensors 1 (1 _FL , 1 _FR , 1 _RL , 1 _RR ) are provided in the interface circuit 4a of the control unit 4 according to the inclination of the vehicle body in the pitch direction. GUD _FL , GUD _FR , GUD _RL , GUD _RR
The longitudinal acceleration / deceleration component GudFB (GudF
_{B FL, GudFB FR, GudFB RL} , with obtaining the GudFB _RR), front-rear direction acceleration component GudFB (GudFB _FL, GudFB
The vertical acceleration G (G _FL , G _FR , G _RL , G) of the vehicle body in the absolute space in which _FR , GudFB _RL , GudFB _RR is canceled.
_RR ) A signal processing circuit for _{obtaining a} signal and a vertical G sensor 1 (1 _FL , 1 _FR , 1 _RL , 1 _RR ) depending on the roll inclination of the vehicle body.
Vertical acceleration GUD (GUD _FL , G
Lateral acceleration component GudLR (GudLR _FL , GudLR _FR , GudLR _RL , GudLR _RR ) included in the UD _FR , GUD _RL , GUD _RR signal
And the lateral acceleration / deceleration component GudLR (GudLR).
_FL , GudLR _FR , GudLR _RL , GudLR _RR ), the vertical acceleration G (G _FL ,
G _FR , G _RL , G _RR ) signal processing circuit for _obtaining signals, and vertical acceleration G (G _FL , G _FR , G) of the vehicle body in absolute space
_RL , G _RR ), and a signal processing circuit for obtaining the vertical speed Δx on the sprung at each shock absorber SA position and the relative speed between the sprung and unsprung (Δx−Δx ₀ ) are provided. . FIGS. 28 and 29 are explanatory diagrams of the operation of these signal processing circuits. The contents of these signal processing circuits are substantially the same as those of the first embodiment of the present invention shown in FIGS. Detailed description is omitted.

With the above-described configuration, the same effects as those of the first embodiment can be obtained in a normal vehicle.

(Third Embodiment of the Invention) A vehicle inclination angle detecting apparatus according to a third embodiment of the present invention obtains a longitudinal acceleration signal and a lateral acceleration signal of a vehicle from a wheel speed signal detected by a wheel speed sensor. This will be described below with reference to FIGS. In the description of the third embodiment of the present invention, the same components as those of the first and second embodiments of the present invention are denoted by the same reference numerals, and the description thereof will be omitted. Only the differences will be described.

FIG. 30 is a structural explanatory view showing a vehicle suspension system to which the vehicle inclination angle detecting device according to the third embodiment of the present invention is applied. As shown in FIG. Instead of the lateral G sensor, a wheel speed sensor 9 ( _9FL , _9FR , _9RL , _9RR ) for detecting the wheel speed Ws is provided.

FIG. 31 shows the wheel speeds Ws (Ws _FL , Ws
s _FR , Ws _RL , Ws _RR ) signal, the longitudinal acceleration Gud
It is a block diagram showing a signal processing circuit for obtaining FB. First, at E1, four wheel speeds Ws _FL , Ws _FR , W
An average value of s _RL and Ws _RR is obtained, and in E2, after a noise removal process is performed by a low-pass filter LPF (30 Hz), a differentiation process is performed in (E3 ₎ ((Ws _(n) −Ws _(n−1) ).
/ Tn) to determine the longitudinal acceleration GFB of the vehicle. Note that Tn is a sampling time.

FIG. 32 shows the wheel speeds Ws (Ws _FL , Ws
s _FR , Ws _RL , Ws _RR ) A signal processing circuit for obtaining the lateral acceleration GLR from the signals.
1, in F2, the wheel speed Ws _FR signals of the wheel speed Ws _FL signal and right front wheels of front left wheel, after the noise removal processing by the low pass filter LPF (30 Hz), respectively, both the wheel speed signals Ws _FL in F3, Ws _{From RL} ,
Calculating a lateral acceleration GLR of the vehicle (GLR = (Ws _FL ² -W
s _RL ² ) / 2W). W is the tread of the vehicle.

As described above, in the third embodiment of the present invention,
By obtaining the longitudinal acceleration GFB signal and the lateral acceleration GLR signal of the vehicle from the wheel speed signal detected by the wheel speed sensor 9, in a vehicle equipped with an anti-skid control device, a longitudinal G sensor and a lateral G sensor are separately provided. There is no need to provide a sensor, so that the system cost can be reduced.

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 first embodiment of the invention, an example has been shown in which the cab pitch angle detecting means and the roll angle detecting means are obtained by calculation from longitudinal acceleration / deceleration signals or lateral acceleration signals. Alternatively, by obtaining data of the actual vehicle and performing linear interpolation, a corresponding map as shown in FIGS. 25 and 26 is created, and this map is used, or a function is obtained in advance,
This may be used.

In the first embodiment of the present invention, the case in which the air spring 36 is provided is shown. Instead of the air spring 36, as shown in FIG.
May be used.

[0077]

As described above, the first aspect of the present invention is as follows.
In the vehicle inclination angle detection device described above, as described above, the vehicle inclination angle calculation unit is configured to set the vehicle inclination angle to a predetermined value when the vehicle behavior detected by the vehicle behavior detection unit is equal to or greater than a predetermined value. Is fixed, the inclination angle exceeding the actual inclination angle of the vehicle is prevented from being detected, and the effect that the inclination angle of the vehicle can be accurately detected is obtained. can get. Further, in the vehicle inclination angle detecting device according to the second aspect, the vehicle behavior detecting means for detecting the behavior of the vehicle is constituted by a longitudinal acceleration detecting means for detecting a longitudinal acceleration of the vehicle, and the vehicle inclination angle calculating means is provided. Is constituted by vehicle pitch angle calculating means for calculating the pitch angle of the vehicle, the pitch angle of the vehicle generated at the time of vehicle braking can be accurately detected, so that the suspension and the anti-skid control device are accurately controlled. Will be able to do it. Further, in the vehicle inclination angle detecting device according to claim 3, the vehicle behavior detecting means for detecting the behavior of the vehicle includes:
The vehicle inclination angle calculating means for calculating a vehicle roll angle is constituted by a lateral acceleration detecting means for detecting a lateral acceleration of the vehicle, and the vehicle inclination angle calculating means is constituted by a vehicle roll angle calculating means for calculating a roll angle of the vehicle. Since the roll angle can be accurately detected, the suspension and the anti-skid control device can be accurately controlled. Further, in the vehicle inclination angle detecting device according to the fourth aspect, the vehicle behavior detecting means includes a longitudinal acceleration detecting means for detecting a longitudinal acceleration of the vehicle and a lateral acceleration detecting means for detecting a lateral acceleration of the vehicle. The vehicle inclination angle calculating means includes a vehicle pitch angle calculating means for calculating a pitch angle of the vehicle and a vehicle roll angle calculating means for calculating a roll angle of the vehicle. Since the pitch angle and the roll angle of the vehicle can be accurately detected, the suspension and the anti-skid control device can be accurately controlled. Further, in the vehicle inclination angle detecting device according to the fifth aspect, the longitudinal acceleration detecting unit and / or the lateral acceleration detecting unit constituting the vehicle behavior detecting unit may detect the vehicle speed from the wheel speed detected by the wheel speed detecting unit. By detecting the longitudinal acceleration and / or the lateral acceleration of the vehicle, the vehicle equipped with the anti-skid control device does not require an additional acceleration sensor, so that the system cost can be reduced. Become.

[Brief description of the drawings]

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

FIG. 2 is a perspective view showing a cab portion of a cab-over type vehicle in a configuration explanatory view showing a cab suspension control device according to Embodiment 1 of the present invention.

FIG. 3 is a side view showing the entire cab-over type vehicle in the configuration explanatory view showing the cab suspension control device according to the first embodiment of the present invention.

FIG. 4 is a system block diagram showing a cab suspension control device according to the first embodiment of the present invention.

FIG. 5 is a sectional view showing a shock absorber applied to the first embodiment of the invention.

FIG. 6 is an enlarged sectional view showing a main part of the shock absorber.

FIG. 7 is a damping force characteristic diagram corresponding to a piston speed of the shock absorber.

FIG. 8 is a damping force characteristic diagram corresponding to a step position of a pulse motor of the shock absorber.

FIG. 9 is a view K of FIG. 6 showing a main part of the shock absorber;
It is -K sectional drawing.

FIG. 10 is a sectional view taken along line LL and line MM of FIG. 6 showing a main part of the shock absorber.

FIG. 11 is a view showing a main part of the shock absorber;
It is -N sectional drawing.

FIG. 12 is a damping force characteristic diagram when the shock absorber is on the extension side hard.

FIG. 13 is a damping force characteristic diagram of the shock absorber in the soft state on the extension side / compression side.

FIG. 14 is a damping force characteristic diagram of the shock absorber in a pressure-side hard state.

FIG. 15 is a block diagram showing a signal processing circuit for obtaining a vertical acceleration signal of a cab in an absolute space in which a longitudinal acceleration / deceleration component is canceled.

FIG. 16 is an operation explanatory diagram of the signal processing circuit of FIG. 15;

FIG. 17 is a diagram showing the relationship between the longitudinal acceleration / deceleration of the vehicle and the pitch angle of the vehicle.

FIG. 18 is a block diagram showing a signal processing circuit for obtaining a vertical acceleration signal of a cab in an absolute space in which a lateral acceleration component has been canceled.

FIG. 19 is a diagram illustrating the operation of the signal processing circuit of FIG. 18;

FIG. 20 is a diagram illustrating a relationship between a lateral acceleration of a vehicle and a roll angle of the vehicle.

FIG. 21 is a diagram showing the vertical speed of the cab (spring-up) and the distance between the cab and the chassis (spring-up) according to the first embodiment of the invention;
It is a block diagram which shows the signal processing circuit which calculates | requires the relative speed (during unsprung).

FIG. 22 is a diagram showing a gain characteristic (a) and a phase characteristic (b) of a cab (spring-up) vertical speed signal obtained by the signal processing circuit of FIG. 21;

FIG. 23 is a flowchart showing the details of the damping force characteristic control operation of the control unit.

FIG. 24 is a time chart showing the details of the damping force characteristic control operation of the control unit.

FIG. 25 is a map showing the relationship between the longitudinal acceleration / deceleration of the vehicle and the pitch angle of the vehicle.

FIG. 26 is a map showing the relationship between the lateral acceleration of the vehicle and the roll angle of the vehicle.

FIG. 27 is a configuration explanatory view showing a vehicle suspension device to which the vehicle inclination angle detection device according to the second embodiment of the present invention is applied.

FIG. 28 is an operation explanatory diagram of a signal processing circuit for obtaining a vertical acceleration signal on a spring in an absolute space in which a longitudinal acceleration / deceleration component is canceled according to the second embodiment of the present invention;

FIG. 29 is an operation explanatory diagram of a signal processing circuit for obtaining a vertical acceleration signal on a spring in an absolute space in which a lateral acceleration / deceleration component is canceled according to the second embodiment of the present invention;

FIG. 30 is a configuration explanatory view showing a vehicle suspension device to which the vehicle inclination angle detection device according to the third embodiment of the invention is applied.

FIG. 31 is a block diagram showing a signal processing circuit for obtaining a longitudinal acceleration from a wheel speed signal.

FIG. 32 is a block diagram showing a signal processing circuit for obtaining a lateral acceleration from a wheel speed signal.

FIG. 33 is a sectional view showing an applied shock absorber when a suspension spring is used instead of an air spring.

[Explanation of symbols]

 a Both behavior detecting means b Vehicle inclination angle calculating means

Claims (5)

[Claims] 1. A vehicle inclination detecting apparatus comprising: vehicle behavior detecting means for detecting the behavior of a vehicle; and vehicle inclination angle calculating means for calculating a vehicle inclination angle from the vehicle behavior detected by the vehicle behavior detecting means. Wherein the vehicle inclination angle calculation means is configured to fix the inclination angle of the vehicle to a predetermined value when the vehicle behavior detected by the vehicle behavior detection means is equal to or greater than a predetermined value. Vehicle inclination angle detecting device. 2. The vehicle behavior detecting means for detecting the behavior of the vehicle includes longitudinal acceleration detecting means for detecting longitudinal acceleration of the vehicle, and the vehicle inclination angle calculating means calculates a pitch angle of the vehicle. 2. The vehicle inclination angle detecting device according to claim 1, comprising a vehicle pitch angle calculating means. 3. The vehicle behavior detecting means for detecting the behavior of the vehicle comprises a lateral acceleration detecting means for detecting a lateral acceleration of the vehicle, and the vehicle tilt angle calculating means calculates a roll angle of the vehicle. 2. The vehicle inclination angle detecting device according to claim 1, comprising a vehicle roll angle calculating means. 4. The vehicle behavior detecting means for detecting the behavior of the vehicle includes longitudinal acceleration detecting means for detecting longitudinal acceleration of the vehicle and lateral acceleration detecting means for detecting lateral acceleration of the vehicle. Vehicle inclination angle calculating means,
2. The vehicle inclination angle detecting device according to claim 1, comprising a vehicle pitch angle calculating means for calculating a pitch angle of the vehicle and a vehicle roll angle calculating means for calculating a roll angle of the vehicle. 5. A longitudinal acceleration detecting means and / or a lateral acceleration detecting means constituting said vehicle behavior detecting means, wherein the longitudinal acceleration of the vehicle and / or the lateral acceleration of the vehicle are determined based on the wheel speed detected by the wheel speed detecting means. 3. The apparatus according to claim 2, wherein the directional acceleration is detected.
The vehicle inclination angle detection device according to any one of claims 1 to 4.