JPH10309920A - Vehicle rolling angle suppressing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a vehicle from being unable to revert to its original posture by itself, by preliminary detecting that the vehicle is getting into a state where it is unable to revert to its original posture by itself. SOLUTION: An inclination sensor 18 detects an inclination, and a rolling sensor 20 detects an angular velocity of rolling rotary motion. An ECU 22 determines, based on an inclination and an angular velocity thus detected, whether or not the state of a vehicle 10 after a predetermined period will be one in which it is unable to revert to its original posture by itself. If determining that the vehicle state after the predetermined period will be such a state, the ECU 20 actuates a gas generator 46L so that a suspension 16L on the rolling side is elongated. The gas that the actuated generator 46L produces is supplied to the chamber in the suspension 16L to thus enlarge the chamber or elongate the suspension 16L.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle roll angle reduction device, and more particularly, to a vehicle roll angle reduction device that selectively extends a pair of suspensions to reduce a vehicle roll angle.

[0002]

2. Description of the Related Art Conventionally, a pair of left and right air springs each having one end connected to an axle with wheels mounted on the left and right sides and the other end connected to a frame of a vehicle body, a high-pressure air tank,
A low-pressure vacuum tank, a first connection path provided on the pair of left and right air springs for connecting the pair of left and right air springs via the air tank, and a second connection for connecting each of the pair of left and right air springs to the vacuum tank. A tilt angle reduction device including a pair of left and right switching valves for switching between the paths, a sensor for detecting the length of a pair of left and right air springs, and a CPU for controlling the switching valve based on the length detected by the sensor has been proposed. Yes (Min. Sho 59-468)
No. 55 (see Japanese Utility Model Application Laid-Open No. 60-1575091).

When the CPU of the inclination angle reducing device detects that the vehicle is greatly inclined from the length inspected by the sensor, that is, when it detects that the inclination angle of the vehicle is equal to or greater than a predetermined angle, the CPU of the inclination angle reducing device detects the inclination of the vehicle. The switching valve is controlled such that the second connection path is formed in the air spring on the side opposite to the direction. As a result, the air in the air spring on the side opposite to the inclination direction is discharged to the vacuum tank, and the air spring is contracted to reduce the inclination angle of the vehicle.

A pair of left and right air bellows, a high-pressure air tank, and an air tank and a pair of left and right air bellows are connected at one end to an axle having wheels mounted on the left and right sides and the other end to a frame of the vehicle body, respectively. Air pipe,
A pair of left and right air bellows provided on each side of a pair of left and right air bellows, and a pair of left and right open / close valves for opening and closing an air pipe, and a pair of air bellows provided on a pair of right and left air bellows are operated when the vehicle is inclined by a predetermined angle, and are compressed by the inclination. A leveling valve operation prevention device provided with an opening mechanism for opening an on-off valve provided on the air bellows side has been proposed (Invention Association Open Technical Report (Publication No. 87-3812)). In this device, when the vehicle is tilted by a predetermined angle, the opening mechanism operates, and the release valve on the side of the tilt direction is opened. As a result, the air in the air tank flows into the air bellows on the tilt direction side, and the air bellows extends, thereby reducing the tilt angle of the vehicle.

[0005]

By the way, when the inclination angle reducing device detects that the inclination angle of the vehicle is equal to or more than a predetermined angle, the air in the air spring opposite to the inclination direction is supplied to the vacuum tank. Emissions reduce the angle of inclination of the vehicle. Therefore, when the inclination angle is small,
Does not reduce the angle of inclination of the vehicle.

[0006] Further, the leveling valve operation preventing device includes:
Since the opening mechanism does not operate unless the vehicle is tilted by a predetermined angle, the tilt angle of the vehicle is not reduced when the tilt angle is small, as in the above-described tilt angle reducing device.

However, in the case where the turning movement of the vehicle in the rolling direction is large, the inclination angle of the vehicle becomes a predetermined angle or more as in the above-described inclination angle reduction device, and the air spring in the air spring on the opposite side to the inclination direction is provided. Even when the air is discharged to the vacuum tank, the force in the direction in which the tilt angle of the vehicle increases due to the above-described pivoting motion is reduced by the force in the direction in which the tilt angle of the vehicle caused by discharging the air in the air spring to the vacuum tank is reduced. In some cases, the force is smaller, the inclination angle of the vehicle is not reduced, and the vehicle cannot return to its own position. The same applies to the leveling valve operation prevention device.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to judge early that a vehicle cannot return to its original state and to prevent the vehicle from returning to its original state. It is an object to provide a possible vehicle roll angle reduction device.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, according to the present invention, each of a pair of wheels mounted on a vehicle with a vehicle front-rear shaft interposed therebetween is mounted and extended and contracted. A pair of suspensions for absorbing wheel vibrations, elongating means for selectively elongating the pair of suspensions, and a roll angle of the vehicle, and a detecting means for detecting a physical quantity representing a magnitude of a rolling motion in a rolling direction; Determining means for determining, based on the roll angle and the physical quantity detected by the detecting means, whether or not the state of the vehicle after a predetermined time is in a state in which self-return is not possible; Control means for controlling the extending means so that the suspension in the rolling direction is extended when it is determined that the state of the vehicle is in a state in which self-return is impossible. To have.

[0010] The detecting means according to the present invention detects the roll angle of the vehicle and a physical quantity representing the magnitude of the motion of rotating in the rolling direction. Note that the physical quantity includes an angular velocity, an angular acceleration, and the like of the motion rotating in the rolling direction. The roll angle and the physical quantity take a predetermined direction positively.

The determining means determines whether or not the state of the vehicle after a predetermined time is in a state where self-return is impossible based on the roll angle and the physical quantity detected by the detecting means. The state in which self-return is impossible is a state in which the vehicle cannot return to the original horizontal state without external force other than the force currently acting on the vehicle, that is, a state in which the roll angle increases.

Here, whether or not the state of the vehicle after a predetermined time is a state in which self-return is impossible can be determined as follows.

For example, it is determined whether or not the position of the center of gravity of the vehicle located after a predetermined time is located at a position where self-return is impossible. That is, as shown in FIG. 4, the rotation center (wheel position) O of the rolling motion in the rolling direction when the vehicle is in a horizontal state.
And the inclination angle θ ₀ of the straight line L passing through the position G of the center of gravity of the vehicle located after a predetermined time with respect to the horizontal plane in a direction perpendicular to the vehicle longitudinal axis is stored in advance. This inclination angle θ ₀ ,
The predetermined time t, the detected roll angle θ, and the angular velocity ω
, The inclination angle θt of the straight line L after a predetermined time
(= Θ ₀ + θ + ωt). Obtained tilt angle θt
Is greater than or equal to a predetermined value.

Here, the predetermined value is a value having the same sign (±) as the obtained inclination angle θt, and its absolute value is a value within 90 ° or less and close to 90 ° (in addition to 90 °, 80 °, 7
0 °).

If the inclination angle .theta.t in each of the absolute values is equal to or greater than the predetermined value, it is determined that the vehicle's own weight acts in the direction in which the inclination angle .theta.t increases, and the vehicle cannot return by itself. can do.

Further, the rolling moment and the weight of the vehicle are stored in advance, and the detected roll angle and angular velocity (or angular acceleration) and the rotational motion equation of the vehicle (momentum and self-weight to rotate by inertia) are used. Estimating the inclination angle θt when the angular velocity becomes 0, based on the equation that the momentum for stopping the rotation is equal to), and the inclination angle θt when taking the absolute value is equal to or more than the predetermined value. It is determined whether or not. If the inclination angle θt is equal to or larger than the predetermined value, it can be determined that the vehicle's own weight acts in a direction in which the inclination angle increases, and the vehicle cannot return to its own position.

Furthermore, roll angle and angular velocity (or angular acceleration)
(Refer to FIG. 9 (FIG. 9 shows a region of the roll angle and the angular acceleration)), a region R1 in which the inclination angle θt when the angular velocity is 0 is equal to or larger than the predetermined value is obtained. It is determined whether or not a position determined from the detected roll angle and angular velocity (or angular acceleration) is within the region R1.If the position is within the region R1, the inclination angle θt at which the angular velocity becomes 0 is determined. Is greater than or equal to the predetermined value, the weight of the vehicle acts in a direction in which the inclination angle increases,
It can be determined that the vehicle cannot return by itself.

The control means controls the extending means so that the suspension in the rolling direction is extended when the determining means determines that the state of the vehicle after a predetermined time is in a state in which self-return is impossible.

As described above, since it is determined whether or not the state of the vehicle after a predetermined time is in a state where self-return is impossible, it is possible to determine whether the vehicle is in a state where self-recovery is not possible early. Can be determined.

Therefore, when it is determined that the state of the vehicle after a predetermined time is in a state where self-return is impossible, the suspension in the rolling direction is extended, so that the roll angle of the vehicle can be reduced, and the suspension can be reduced. It is possible to prevent a situation where the roll angle of the vehicle is not reduced even when the vehicle is extended.

Here, the suspension may be configured to include a shock absorber and a closed space that is provided between the shock absorber and the vehicle body and that is expandable and contractible and contains gas.

In this case, the extension means may forcibly extend the suspension by forcibly supplying gas to the space.

The suspension may include a shock absorber and a first coil spring wound coaxially with the shock absorber.

In this case, the extension means is provided for extending the second coil spring and the second coil spring which are fixed at one end to the shock absorber, wound coaxially with the first coil spring, and contracted in advance. It may be constituted by a blocking means for blocking and a releasing means for releasing the blocking by the blocking means.

Here, the suspension is provided with an increasing / decreasing means for increasing / decreasing a resistance at the time of expansion / contraction, and the control means, when it is determined that the state of the vehicle after a predetermined time is in a state in which self-return is impossible, rolling is performed. The extension means may be controlled so that the shock absorber on the direction side is extended, and the increasing / decreasing means may be controlled so that the resistance is reduced. Thereby, the extension force for extending the suspension can be used efficiently.

[0026]

Embodiments of the present invention will be described below in detail with reference to the drawings.

As shown in FIG. 1, the vehicle roll angle reducing device of this embodiment includes wheels 12L, 12R mounted on a vehicle 10.
A pair of suspensions 16L, 16R and a pair of suspensions are arranged side by side with the axle 14 (see FIG. 2) and connect the axle 14 and the body 24 (see FIG. 2) and expand and contract to absorb the vibration of the vehicle 10. 16L, 1
A gas is forcibly supplied to a chamber chamber 38 (see FIG. 2) of each of the 6Rs 6R, and a pair of suspensions 16L,
A gas generator 46L for forcibly extending each of the 16Rs;
46R. The gas generators 46L, 46L
R corresponds to the extension means of the present invention.

Further, the vehicle roll angle reduction device of the present embodiment
An inclination sensor (clinometer) 18 for detecting a roll angle θ of the vehicle 10, that is, an inclination angle θ with respect to a horizontal plane in a direction perpendicular to the vehicle longitudinal axis (perpendicular to the paper surface of FIG. 1). As shown in FIG. 5, the inclination angle θ is positive when the vehicle is inclined leftward in the traveling direction.

Further, the vehicle roll angle reducing device of the present embodiment
The vehicle 10 is provided with a rolling sensor (gyro-type using a piezoelectric element or the like) 20 for detecting a physical quantity representing the magnitude of the rotational motion in the rolling direction (rotational motion about the longitudinal axis of the vehicle), in this embodiment, an angular velocity ω. I have. This angular velocity ω is
As shown in (1), the direction in which the vehicle turns left in the traveling direction is positive.

Here, the same processing is performed for the case where the inclination angle θ and the angular velocity ω are positive and negative, respectively. Therefore, the case where the inclination angle θ and the angular velocity ω are positive will be described below as an example.

Incidentally, the inclination sensor 18 and the rolling sensor 20 constitute the detecting means of the present invention. Further, instead of the rolling sensor 20, the angular acceleration may be directly detected by using a sensor.

Further, the vehicle roll angle reduction device of the present embodiment
The ECU 22 is connected to the inclination sensor 18, the rolling sensor 20, and the gas generators 46L, 46R, and controls the gas generators 46L, 46R. The ECU 22 includes a CPU, a ROM, and the like (not shown). In this ROM, a program corresponding to a control routine described later and a rotational motion equation of the vehicle described later are stored in advance.

The ECU 22 corresponds to the control means of the present invention. Next, the suspensions 16L and 16R and the gas generators 46L and 46R will be described. Since they have the same configuration, only the suspension 16L and the gas generator 46L will be described, and the suspension 16R and the gas generator 46R will be described. Description is omitted.

As shown in FIG. 2, the suspension 16R includes a connecting member 34 for connecting to the body 24 of the vehicle 10. One end of a piston rod 36 is connected to the connecting member 34. The other end of the piston rod 36 is housed in a shock absorber 42 connected to the axle 14.

The shock absorber 42 is divided into an inner cylinder 41 and an outer cylinder 43 centering on the piston rod 36. The inner cylinder 41 has an upper chamber 42UR and a lower chamber 42D separated by a rotary valve 44 provided at the tip of the piston rod 36.
It is divided into R. The upper chamber 42UR and the lower chamber 42
DR contains oil, and the oil can move between the upper chamber 42UR and the lower chamber 42DR via an orifice (small hole) provided in the rotary valve 44. A motor M for increasing or decreasing the opening area of the orifice of the rotary valve 44 is disposed above the piston rod 36 via a mechanism inside the piston rod 36, and the motor M is connected to the ECU 22.

A valve 45 provided with an orifice 47 is provided below the inner cylinder 41, and a high-pressure gas 43B is accommodated in the outer cylinder 43. The oil accommodated in the lower chamber 42DR is , Can be moved to the outer cylinder 43 through an orifice 47 provided in the valve 45, and conversely,
The oil 43A stored in the outer cylinder 43 can move to the lower chamber 42DR via an orifice provided in the valve 45.

A chamber 38 is provided between the connecting member 34 and the shock absorber 42, and the chamber chamber 3
A high-pressure gas is stored in 8. Chamber room 38
Is connected to a gas generator 46R. The gas generator 46R contains a gas generating agent in the gas generating agent chamber 52, is connected to the gas generating agent chamber 52, and is connected to the ECU 22.
And an ignition device 58 connected to the ignition device. In addition, the gas generating agent chamber 52 and the chamber chamber 38 are communicated via a predetermined communication port.

Next, the operation of the present embodiment will be described. First, the operation of the suspension 16R will be described.

For example, when the wheel 12R runs on a convex road surface, the upward vibration of the wheel 12R is transmitted to the shock absorber 42, and the shock absorber 42 is supported by the piston rod 36 and rises (see arrow U). .

When the shock absorber 42 rises, the volume of the chamber 38 decreases and the internal pressure rises by the rise of the shock absorber 42. This increase in the internal pressure becomes the air spring force. Therefore, the upward vibration of the wheel 12R is absorbed by the spring force caused by the increase in the internal pressure of the chamber 38.

At this time, the rotary valve 44 provided at the tip of the piston rod 36 is connected to the shock absorber 42
Attempt to move downward relative to. As a result, part of the oil in the lower chamber 42DR in the inner cylinder 41 attempts to move to the upper chamber 42UR (see arrow A) via the orifice provided in the rotary valve 44, and the oil in the inner cylinder 41 Another part of the oil in the lower chamber 42DR is the inner cylinder 4
1 Attempts to move to the outer cylinder 43 via the orifice 47 of the valve 45 provided at the lower part (see arrow B). As described above, the movement of the oil in the lower chamber 42DR in the inner cylinder 41 suppresses the sudden rise of the shock absorber 42. A force acts to lower the shock absorber 42 by a spring force caused by an increase in the internal pressure of the chamber 38, but the lower chamber 42DR in the inner cylinder 41 responds to this force.
The movement of the oil inside (the movement direction is the opposite direction to the above-mentioned direction) serves as a resistance, thereby preventing the shock absorber 42 from being repeatedly raised and lowered.

FIG. 3 shows a control routine repeatedly executed by the ECU 22 at predetermined time intervals.
In step 2, the inclination angle θ and the angular velocity ω are read, and in step 64, the state of the vehicle 10 after a predetermined time is calculated.

That is, as described above, since the rotational motion equation of the vehicle is stored in advance, the vehicle 10 has a rotational motion equation based on the detected inclination angle θ and angular velocity ω and the rotational motion equation of the vehicle. As the state after the predetermined time, the inclination angle θt (see FIG. 4) of the straight line L passing through the rotation center (wheel position) O and the center of gravity G of the rolling motion in the rolling direction when the angular velocity ω becomes 0 with respect to the horizontal plane is estimated. I do.

Here, the equation of rotational motion of the vehicle will be described. This rotational motion equation is obtained from equation (1),
The left side shows the momentum to rotate by inertia, and the right side shows the momentum to stop rotation by its own weight.

[0045]

(Equation 1) Here, I is the rolling moment, M is the vehicle weight, g is the gravitational acceleration, D is the distance from the rotation center (wheel position) O of the rotation in the rolling direction to the center of gravity G, and θ is the inclination angle.

The rolling moment I is obtained as follows. That is, as shown in FIG. 7, the rolling moment Ii of the mass mi at a position at a distance ri from the rotation center (wheel position) O of the rotation in the rolling direction is:

[0047]

## EQU2 ## Ii = mi × ri (2), and the rolling moment I of the entire vehicle is

[0048]

## EQU3 ## I = Σ (mi × ri) (3), which is a constant that varies depending on the vehicle.

In step 66, it is determined whether or not the state of the vehicle 10 after a predetermined time is a state in which self-recovery is not possible. That is,
It is determined whether or not the inclination angle θt when the angular velocity ω becomes 0 is equal to or more than the predetermined value. When the inclination angle θt when the angular velocity ω is 0 is equal to or more than the predetermined value, the inclination angle θ is determined.
When t is the above-mentioned predetermined value, the angular velocity ω is equal to or greater than 0, and the weight of the vehicle acts in the direction in which the inclination angle increases, and it can be determined that the vehicle cannot self-return. Step 66 corresponds to a determination unit.

If it is determined that the state of the vehicle 10 after the predetermined time is not a state in which self-return is not possible, the flow returns to step 62 and the above processing (steps 62 to 66) is repeated.

On the other hand, if it is determined that the state of the vehicle 10 after a predetermined period of time is a state in which self-return is not possible, it is possible to determine that the inclination angle θt will be further increased if the vehicle 10 is left as it is. Therefore, it is necessary to reduce the inclination angle. In addition,
The rolling direction (inclination direction) may be rightward or leftward with respect to the traveling direction of the vehicle.
At 8, the inclination direction is determined. Note that the inclination direction can be determined based on whether the inclination angle θ and the angular velocity ω are positive or negative. That is,
When the inclination angle θ and the angular velocity ω are positive, the inclination direction can be determined to be left, and when the inclination angle θ and the angular velocity ω are negative, the inclination direction can be determined to be right.

If it is determined that the tilt direction is left, a left shock absorber reaction force is generated in step 70, and if it is determined that the tilt direction is right, step 7 is performed.
2, a right shock absorber reaction force is generated.

That is, for example, when a left-side shock absorber reaction force is generated, an ignition current is supplied to the ignition device 58 of the gas generator 46L, and the rotary valve 4
4 so that the opening area of the orifice 4 is maximized.
Control.

When the ignition current is supplied to the ignition device 58, the ignition device 58 is ignited, and the gas generating agent explodes to generate gas. The gas thus generated is supplied to the chamber 38 through the communication port, and the internal pressure of the chamber 38 increases. This increase in internal pressure becomes an air spring force, and attempts to push the shock absorber 42 downward.

At this time, since the opening area of the orifice of the rotary valve 44 is maximized by controlling the motor M,
The oil stored in the upper chamber 42UR of the inner cylinder 41 easily flows through the orifice of the rotary valve 44 to the lower chamber 42D.
You can move to R. Thus, the air spring force due to the increase in the internal pressure of the chamber 38 can be used to the maximum.

On the other hand, the axle 14 is connected to the lower part of the shock absorber 42, and the axle 14 cannot be fixed and moved downward. Therefore, as described above, when a force is generated to push the shock absorber 42 downward, the force acts as a reaction force and pushes the body 24 upward.

Therefore, as shown in FIG. 5, the side of the vehicle 10 in the direction of inclination (left side) is at the position of the vehicle 100 (indicated by a dotted line).
Is pushed up. As a result, the inclination angle decreases, and the inclination of the vehicle 10 can be reduced.

As described above, in this embodiment, since the state of the vehicle after a predetermined time is estimated, it is possible to early estimate that the vehicle will be in a state in which it cannot return to its original state. If the position is a position where self-return is impossible, a shock absorber reaction force in the inclined direction is generated, so that it is possible to prevent the vehicle from being unable to self-return.

In the embodiment described above, an air suspension is described as an example, but the present invention is not limited to this, and a coil suspension may be used.

That is, as shown in FIG. 6, the coil suspension has a shock absorber 42. The shock absorber 42 is connected to the connecting member 14A. The connecting member 14A is connected to a steering knuckle (not shown) connected to the wheels.

The coil suspension has a coil spring 80 wound coaxially with the shock absorber 42. The coil spring 80 is wound between the upper coil spring seat 33 connected to the body 24 and the lower coil spring seat 31 fixed to the shock absorber 42.

Further, the coil suspension includes a coil spring 82 compressed in advance, a stopper 86 for stopping the extension of the coil spring 82, and an actuator 84 for releasing the stopper 86. The coil spring 8
2, by the stopper 86 and the actuator 84,
This constitutes the extension means of the present invention.

As described above, when it is determined that the state of the vehicle 10 after a predetermined time is a state in which self-return is impossible, the actuator 84 in the tilt direction is driven. This releases the stopper 86 (breaks or retracts).
Then, the coil spring 82 is about to extend above the upper coil spring seat 33, and the inclined side of the vehicle 10 is pushed up to the position of the vehicle 100 (indicated by a dotted line). Thereby, the inclination angle of the vehicle 10 can be reduced.

In the above-described embodiment, the inclination angle θt at which the angular velocity becomes 0 is determined based on the rotational motion equation, the detected roll angle, and the angular velocity (or angular acceleration).
Is estimated, and it is determined whether or not the estimated inclination angle is equal to or larger than the predetermined value. However, the present invention is not limited to this, and may be obtained as follows.

Using a sensor for detecting angular acceleration, as shown in FIG. 9, in a region defined by the roll angle θ and the angular acceleration (dω / dt), the angular velocity of a straight line passing through the center of rotation and the position of the center of gravity with respect to the horizontal plane A first region R1 in which the inclination angle when ω is 0 is equal to or more than the predetermined value, and a second region in which the inclination angle when the angular velocity ω of the straight line with respect to the horizontal plane is 0 is less than the predetermined value. R2 is obtained. The boundary between the first region R1 and the second region R2 is a self-return limit value.

Then, it is determined whether or not the position determined from the detected roll angle θ and the angular acceleration (dω / dt) is within the first region R1.

The detected roll angle θ and the angular acceleration (dω /
dt) as shown in FIG.
In the case of the position, there is an angular acceleration larger than the self-return limit value, and it is determined that the obtained position is within the first region R1. In this case, the straight line L when the angular velocity ω becomes 0
Since the inclination angle of the vehicle with respect to the horizontal plane is equal to or greater than the predetermined value, it can be determined that the vehicle's own weight acts in the direction in which the inclination angle increases, and the vehicle cannot return by itself.
The detected roll angle θ and angular acceleration (dω / dt)
If the position determined from is the position in state 2, state 2
Since the rolling angle is relatively large but the angular acceleration is small, it is determined that the obtained position is within the second region R2. In this case, since the inclination angle of the straight line L with respect to the horizontal plane when the angular velocity becomes 0 is less than the predetermined value,
It can be determined that the vehicle can return by itself.

In the above description, the sensor for detecting the angular acceleration is used, but the determination may be made as described above using a rolling sensor.

When the vehicle is horizontal, the inclination angle θ ₀ between the straight line L and the horizontal plane perpendicular to the vehicle longitudinal axis is stored in advance.

The vehicle 10 is determined based on the previously stored tilt angle θ ₀ , the detected tilt angle θ, and the angular velocity ω.
The wheel position O and the predetermined time t
Of a straight line L passing through the position G of the center of gravity of the vehicle located behind,
Tilt angle θt with respect to the horizontal plane in the direction perpendicular to the vehicle longitudinal axis
(= Θ ₀ + θ + ωt).

Then, it is determined whether or not the inclination angle θt at each of the absolute values is equal to or larger than the predetermined value. If the obtained inclination angle θt is equal to or larger than the predetermined value, the inclination angle θ
It can be determined that the vehicle's own weight acts in the direction in which t increases, and the vehicle cannot return to its own state.

[0072]

As described above, according to the present invention, since it is determined whether or not the state of the vehicle after a predetermined time is in a state in which self-return is impossible, the vehicle is in a state in which self-return is not possible. It is possible to determine at an early stage whether or not the vehicle state after a predetermined time is in a state in which self-recovery is impossible, so that the suspension in the rolling direction is extended, thereby reducing the roll angle of the vehicle. Therefore, it is possible to prevent a situation in which the roll angle of the vehicle is not reduced even if the suspension is extended.

[Brief description of the drawings]

FIG. 1 is a block diagram of a vehicle roll angle reduction device.

FIG. 2 is a view showing a suspension.

FIG. 3 is a flowchart illustrating a control routine of the vehicle roll angle reduction device.

FIG. 4 shows the inclination angle of a straight line passing through the rotation center (wheel position) of the rotational motion in the rolling direction and the position of the center of gravity of the vehicle located after a predetermined time with respect to a horizontal plane in a direction perpendicular to the vehicle longitudinal axis. FIG.

FIG. 5 is a diagram showing a state before and after the inclination angle of the vehicle is reduced.

FIG. 6 is a view showing another example of a suspension.

FIG. 7 is a diagram showing the mass at a position at a predetermined distance from the rotation center (wheel position) of the motion rotating in the rolling direction.

FIG. 8 is an explanatory diagram illustrating a rotational motion equation.

FIG. 9 is a diagram that defines an area where the vehicle can self-return and an area where the vehicle cannot return in the area of the roll angle and the angular velocity.

[Explanation of symbols]

 16L, 16R Suspension 18 Tilt sensor (detection means) 20 Rolling sensor (detection means) 22 ECU (control means) 42 Shock absorber 46R, 46L Gas generator (extension means)

Claims (1)

[Claims] 1. A pair of suspensions which are mounted corresponding to a pair of wheels mounted on a vehicle with a vehicle longitudinal axis interposed therebetween and which expand and contract to absorb vibration of each wheel, and a pair of the suspensions are selected. Based on the roll angle of the vehicle, and a roll angle of the vehicle, and a detection unit that detects a physical quantity representing the magnitude of the motion that rotates in the rolling direction. Determining means for determining whether the state of the vehicle after a predetermined time is a state in which self-return is not possible; and determining that the state of the vehicle after the predetermined time is a state in which self-recovery is not possible Control means for controlling the extending means so that the suspension in the rolling direction is extended.