JP2002274306A - Rollover prevention device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve safety in driving a vehicle by alarming danger of rollover of the vehicle at an optimal timing while applying generality to hardware. SOLUTION: A roll angel θ is calculated from heights HL and HR of left/right of the vehicle (S1 and S2), a moving average is set to a average roll angle θave (S3), and a roll angular speed ωis calculated from the change rate of the average roll angle θave (S4). Thresholds θ1 -θ3 determining the danger of the vehicle rollover are set based on parameters expressing variably set vehicle characteristics (S5). When the absolute value of the average roll angle θave is larger than a prescribed value ω0 (S6), a roll emergency degree according to the roll angle θ is determined (S7-S11). When the absolute value of the average roll angle θave is larger than an addition value between the thresholds θ1 -θ3 and correction values Δθ1 -Δθ3 according to a roll emergency degree, an alarm lamp or an alarm is operated to alarm that there is the danger of rollover the vehicle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for warning the danger of a vehicle rollover at an optimal timing and improving the safety of the vehicle operation.

[0002]

2. Description of the Related Art When a vehicle makes a sharp turn or enters a corner at an overspeed, the vehicle may roll excessively and roll over. Further, in a vehicle such as a truck that transports luggage, since the center of gravity is increased by loading luggage, the roll angle becomes larger than in other vehicles, and the danger of rollover increases.

As a device for informing a driver of a roll angle of a vehicle, for example, a vehicle tilt display device (hereinafter referred to as a tilt display device) disclosed in Japanese Patent Application Laid-Open No. 5-96985 is known. In such an inclination display device, the inclination angles of the vehicle in the front-rear direction and the left-right direction are detected, the inclination state of the vehicle is displayed by a picture or the like, and an alarm is issued when the inclination angle becomes a predetermined value or more. For this reason, the driver can grasp the inclination state of the vehicle at a glance, and can prevent the vehicle from rolling over.

[0004]

However, the alarm generation control is based on a characteristic unique to a vehicle (hereinafter referred to as "vehicle characteristic").
Therefore, there is a problem as described below. That is, it is known that buses, trucks, tractors, trailers, and the like include various vehicles having different numbers of front-rear shafts, total vehicle length, and total vehicle weight, and have various vehicle characteristics. For this reason, to perform alarm generation control suitable for vehicle characteristics, it is necessary to use hardware optimized for each vehicle, which is truly low in versatility.

[0005] Vehicle characteristics include a load capacity, a load height, and a load height.
It is also known that it changes dynamically according to the vehicle operation state such as the presence or absence of trailer towing. For this reason, in the prior art, an alarm is not always issued at an appropriate timing,
If the warning is delayed, time for the danger avoidance operation cannot be secured, and there is still a danger of the vehicle rolling over. Accordingly, the present invention has been made in view of the conventional problems as described above, and allows a parameter indicating a vehicle characteristic to be variably set, so that versatility is given to hardware and vehicle rollover can be performed at an optimal timing. It is an object of the present invention to provide a vehicle rollover prevention device that can warn of danger and improves safety in vehicle operation.

[0006]

According to the present invention, a roll angle detecting means for detecting a roll angle of a vehicle, a roll angular velocity detecting means for detecting a roll angular velocity of a vehicle, and a detected roll angle are provided. An urgency determining means for determining an urgency corresponding to the angular velocity; a parameter setting means for variably setting a parameter indicating a vehicle characteristic; and a risk of a vehicle rollover corresponding to the urgency based on the set parameter. Threshold setting means for setting a threshold for determining whether the vehicle is in danger of overturning when the absolute value of the detected roll angle is larger than a threshold set in accordance with the urgency Means for issuing a warning to the driver when the danger determining means determines that there is a danger of vehicle rollover, and a rollover prevention device for the vehicle. Characterized by being configured to.

According to this configuration, as the current roll angular velocity increases, it is considered that the roll angle reaches the dangerous angle in a short time, so first the urgency corresponding to the roll angular velocity is determined. Further, a threshold value for determining a risk of vehicle rollover corresponding to the degree of urgency is set based on a parameter indicating a vehicle characteristic variably set. Then, when the absolute value of the roll angle is larger than a threshold value set in accordance with the degree of urgency, it is determined that there is a risk of vehicle rollover, and a warning is issued to the driver.

[0008] Since the threshold value for judging the danger of vehicle rollover is set based on variably set parameters indicating vehicle characteristics, it is possible to cope with various vehicles having different vehicle characteristics with one piece of hardware. . For this reason, versatility is given to the rollover prevention device, hardware can be shared, and transfer to another vehicle is possible. Further, by appropriately setting the parameters indicating the vehicle characteristics, a warning can be issued at an optimal timing suitable for the vehicle.

According to the second aspect of the present invention, a roll angle detecting means for detecting a roll angle of the vehicle, a roll change state detecting means for detecting a roll change state of the vehicle, and a roll change state based on the detected roll angle and roll change state. A roll angle estimating means for estimating a roll angle of the vehicle after a lapse of a predetermined time; an urgency determining means for determining an urgency according to the estimated roll angle; and variably setting parameters indicating vehicle characteristics. Parameter setting means, based on the set parameters, threshold setting means for setting a threshold for determining the risk of vehicle rollover corresponding to the urgency, the absolute value of the detected roll angle, the urgency Danger determining means for determining that there is a danger of vehicle overturn when the threshold value is larger than a threshold value set correspondingly; And when it is determined, characterized in that to constitute a rollover prevention system for a vehicle includes a warning generating means for issuing a warning to the driver, the.

According to this configuration, the roll angle of the vehicle after the lapse of the predetermined time is estimated based on the current roll angle and the roll change state, and the urgency corresponding to the estimated roll angle is determined. Further, a threshold value for determining a risk of vehicle rollover corresponding to the degree of urgency is set based on a parameter indicating a vehicle characteristic variably set. When the current absolute value of the roll angle is larger than a threshold value set in accordance with the degree of urgency, it is determined that there is a risk of vehicle rollover, and a warning is issued to the driver.

[0011] The threshold value for determining the risk of vehicle rollover is set based on a variably set parameter indicating vehicle characteristics, so that one hardware can be used for various vehicles having different vehicle characteristics. . For this reason, versatility is given to the rollover prevention device, hardware can be shared, and transfer to another vehicle is possible. In addition, by appropriately setting parameters indicating vehicle characteristics, a warning can be issued at an optimal timing suitable for the vehicle. Furthermore, since the urgency is determined based on the estimated roll angle, a warning is issued at more optimal timing before the actual roll angle becomes the rollover danger angle. For this reason, the driver can perform the danger avoidance operation with a margin, and the safety in vehicle operation is further improved.

According to a third aspect of the present invention, the roll change state detecting means detects a roll angular velocity or a roll angular acceleration as a roll state of the vehicle. According to this configuration, the roll angle of the vehicle after the lapse of the predetermined time is predicted based on the current roll angle and the roll angular velocity or the roll angular acceleration. For this reason, the roll state of the vehicle is predicted with high accuracy by a simple calculation formula, and a warning is issued at an appropriate timing.

According to a fourth aspect of the present invention, the parameter setting means sets a fixed characteristic peculiar to the vehicle and a variable characteristic dynamically changing according to the vehicle operating state. According to this configuration, in addition to the fixed characteristics unique to the vehicle, the variable characteristics that change according to the vehicle operation state are also taken into account, so that a warning is issued at a more optimal timing suitable for the vehicle.

According to a fifth aspect of the present invention, a vehicle height detecting means for detecting a vehicle height on the left and right sides of the vehicle, a roll angle calculating means for calculating a roll angle based on the detected vehicle height, and a calculated roll angle Moving average calculating means for calculating a moving average of the angle, wherein the roll angle detecting means sets a moving average of the calculated roll angles as a roll angle.

According to this configuration, the roll angle is calculated based on the vehicle height on the left and right sides of the vehicle, the moving average of the roll angles is calculated, and the moving average of the roll angles is used as the roll angle of the vehicle. For this reason, for example, even if a fine vibration due to unevenness of the road surface is detected, it is smoothed by calculating the moving average, thereby preventing an inappropriate warning from being issued.

In the invention according to claim 6, when the danger determining means determines that there is a danger of the vehicle rolling over,
A vehicle deceleration means for decelerating the vehicle is provided. According to such a configuration, when it is determined that there is a risk of the vehicle rolling over, the vehicle is decelerated, so that the centrifugal force acting on the vehicle is reduced, and the roll angle is reduced. For this reason, even if the danger avoidance operation by the driver is delayed, the danger of the vehicle rolling over is reduced.

According to a seventh aspect of the present invention, the vehicle deceleration means is at least one of a brake operation means for operating a brake of the vehicle and a fuel reduction means for reducing the fuel supplied to the engine. And According to such a configuration, the vehicle is decelerated by operating the brake of the vehicle or reducing the fuel supplied to the engine. Therefore, for example, only by transmitting a control command to the brake controller and / or the engine controller, the vehicle can be decelerated, and the control content is prevented from becoming complicated.

In the invention according to claim 8, when the danger determining means determines that there is a danger of the vehicle rolling over,
A roll angle limiting means for mechanically limiting a roll angle of the vehicle is provided. According to this configuration, when it is determined that there is a risk of the vehicle rolling over, the roll angle of the vehicle is mechanically limited. For this reason, the roll angle of the vehicle is reliably prevented from exceeding the critical angle.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the attached drawings. FIG. 1 shows an embodiment in which a vehicle rollover prevention device (hereinafter, referred to as “rollover prevention device”) according to the present invention is applied to a semi-tractor (hereinafter, referred to as “tractor”).

The left and right side frames 10L, 10R and the rear shaft 12 are interposed and connected by a suspension mechanism 14 using a leaf spring or an air spring.
Left and right side frames 10L, the 10R near the side frames 10L, through the distance (interval) between the 10R and the rear shaft 12, the vehicle height sensor 16L for detecting the vehicle height H _L and H _R of the vehicle right and left, 16R ( Vehicle height detecting means). In the vicinity of the driver's seat, a roll indicator 18 that displays the roll state of the vehicle in a pictorial diagram, an alarm timing selection switch 20, and an alarm 22 such as a buzzer (alarm generating means)
And are arranged.

As shown in the drawing, the roll indicator 18 has a pointer 18b, which indicates the roll state of the vehicle, mounted in an annular zone 18a so as to be swingably controllable. At the lower part of the zone 18a, a danger zone 18c indicating that the roll angle is excessive and there is a danger of the vehicle rolling over is displayed in red. Further, the roll indicator 18 is provided with a warning light (warning generating means) warning the driver that there is a risk of the vehicle rolling over. The alarm timing selection switch 20 is a switch for setting a timing at which an alarm is to be output according to the driver's preference. As shown in FIG. And delay C can be selected. That is, when the normal B is selected, the roll angle considered dangerous for the vehicle is selected as the roll angle at which the alarm is generated. On the other hand, when early A or late C is selected, a roll angle larger or smaller by a predetermined angle than a roll angle regarded as dangerous for the vehicle is selected as a roll angle at which an alarm is issued.

Further, as a feature of the present invention, for example, a parameter setting switch 24 (parameter setting means) including a plurality of dip switches is provided in order to variably set parameters indicating vehicle characteristics. The parameter setting switch 24 sets a fixed characteristic unique to the vehicle and a variable characteristic that dynamically changes according to the vehicle operation state. As the fixed characteristics, for example, the number of axes on the front axis (one or two axes), the number of axes on the rear axis (one or two axes), and the overall length of the vehicle (short, medium, or long) are set.
On the other hand, as the variable characteristics, for example, the presence / absence of trailer towing (single vehicle or connection), the loading status (empty, semi-loaded or constant load), and the loading height (low, middle or high) are set. The presence or absence of trailer traction may be determined from the output of a coupler switch (not shown) provided on the coupler.

The outputs of the vehicle height sensors 16L and 16R, the alarm timing selection switch 20 and the parameter setting switch 24 are respectively input to an electronic control unit (hereinafter referred to as "control unit") 26 incorporating a microcomputer. Then, processing described later is executed based on these input signals, and control of the roll indicator 18 and the alarm 22 is performed. When the roll angle of the vehicle is likely to be excessive, the engine speed is reduced to lower the turning speed to make the roll angle somewhat smaller.
8 and a brake command are transmitted to the brake controller 30.

Note that the control unit 26
Roll angle detecting means, roll angular velocity detecting means, urgency determining means, threshold setting means, danger determining means, warning generating means, roll change state detecting means, roll angle estimating means, roll angle calculating means, moving average calculating means, vehicle Deceleration means,
The brake operating means and the fuel reducing means are realized by software.

FIG. 2 shows a functional configuration of the control unit 26. The control unit 26 includes a roll angle calculation unit 26a, a roll angular velocity calculation unit 26b, a roll urgency determination unit 26c, a threshold setting unit 26d, a rollover danger determination unit 26e, an indicator control unit 26f, and an alarm device control. 26g and a deceleration control unit 26h.

The roll angle calculator 26a calculates the current roll angle θ [rad] based on signals from the vehicle height sensors 16L and 16R. Roll angular velocity calculator 2
In step 6b, the current roll angular velocity ω [rad / sec] is calculated based on the change rate of the roll angle θ. The roll urgency determining unit 26c determines the roll urgency based on the roll angle θ and the roll angular velocity ω. here,
The “roll urgency” is a scale indicating the magnitude of the risk of vehicle rollover. In the present embodiment, at least three levels of urgency “large”, urgency “medium”, and urgency “small” are used. Is determined.

In the threshold setting section 26d, thresholds θ _{1 to} θ ₃ (details will be described later) for determining the risk of vehicle rollover are set based on the setting state of the parameter setting switch 24. In the rollover risk judging section 26e, a roll urgency, based on the setting state of the roll angle theta, the threshold theta ₁ through? ₃ and warning timing selection switch 20, whether the vehicle is at risk of rollover is determined . Indicator control unit 26f
Then, the roll indicator 18 is controlled based on the roll angle θ and the determination result of the rollover danger. In the alarm control unit 26g, the alarm 22 is controlled based on the determination result of the rollover danger. The deceleration control unit 26h reduces the fuel supply amount via the engine controller 28 and activates the brake via the brake controller 30 to reduce the vehicle speed based on the determination result of the rollover danger. Then, as the vehicle speed decreases, the turning speed decreases and the roll angle θ decreases, and the danger of vehicle rollover can be reduced to some extent.

FIGS. 3 and 4 show the control unit 2.
6 shows an embodiment of control contents repeatedly executed at predetermined time intervals. In step 1 (abbreviated as “S1” in the figure, the same applies hereinafter), the vehicle height sensors 16L, 16L are provided at predetermined sampling intervals (for example, several msec to several hundred msec).
The vehicle heights H _L and H _{R on the} left and right sides of the vehicle are detected from _R.

In step 2, the current roll angle θ is calculated based on the detected vehicle heights H _L and H _R. When the vehicle makes a left turn, as shown in FIG. 5, the vehicle height H _L on the left side of the vehicle becomes larger than the vehicle height H _R on the right side of the vehicle (H
_L > H _R ). Here, assuming that the mounting interval between the vehicle height sensors 16L and 16R is L, the roll angle θ of the vehicle is θ ≒ tan ⁻¹
It is calculated by the calculation formula ((H _L -H _R ) / L).
The roll angle θ calculated here is a relative angle indicating the inclination of the vehicle with respect to the rear shaft. Note that the processing in step 2 corresponds to the roll angle calculation means.

Here, the roll angle θ of the vehicle may be calculated by the following formula.

[0031]

(Equation 1) Alternatively, the following expression may be used as a more accurate operation expression.

[0032]

(Equation 2) In step 3, the average roll angle θ _ave is calculated.
That is, the roll angle θ is calculated in the step 2, the vehicle height sensors 16L, since a roll angle at the moment of detecting the vehicle height H _L and H _R from 16R, for example, to detect fine vibration due to the unevenness of the road surface I will. Therefore, by calculating a moving average of several to several tens of roll angles θ and using the calculated average as the average roll angle θ _ave , unnecessary sensitivity that causes a malfunction can be eliminated. Step 3
Corresponds to the moving average calculation means. Also,
A series of processes in Steps 1 to 3 correspond to a roll angle detection unit.

In step 4, the roll angular velocity ω of the vehicle is calculated based on the rate of change of the average roll angle _θave . That is, the roll angular velocity ω is calculated by applying the least square method to several to several tens of average roll angles θ _ave . The processing in step 4 corresponds to the roll angular velocity detecting means. In step 5, based on the setting state of the parameter setting switch 24, threshold values θ _{1 to} θ ₃ that determine the risk of vehicle rollover corresponding to each roll urgency are set. Here, as the thresholds θ _{1 to} θ ₃ , for example, values obtained through experiments and the like are used in consideration of the magnitude of the risk of vehicle rollover. Note that the processing in step 5 corresponds to a threshold setting unit.

[0034] In step 6, the absolute value of the average roll angle theta _ave is whether greater than a predetermined value theta ₀ is determined.
Here, the predetermined value θ ₀ is a threshold value at which the processing is not performed when the number of rolls is small, and is set to, for example, a value at which the risk of the vehicle rolling over is extremely low. Then, the absolute value of the average roll angle theta _ave proceeds to step 7 is larger than the predetermined value theta ₀ (Yes), the absolute value of the average roll angle theta _ave finishes processing if ₀ or less than the predetermined value theta (N
o).

[0035] In step 7, the absolute value of the roll angular velocity omega is whether greater than a predetermined value omega ₂ is determined. Here, the predetermined value ω ₂ is a threshold value defining an area where the degree of roll urgency is large. For example, if the current roll angular velocity is ω, a roll angle at which there is a risk of vehicle rollover after a predetermined time has elapsed. It is set to a value estimated to be θ.
Then, if the absolute value of the roll angular velocity omega is greater than the predetermined value omega ₂ proceeds to step 8 (Yes), the roll urgency is judged to be large. On the other hand, the absolute value of the roll angular velocity omega proceeds to step 9 if ₂ or less than the predetermined value omega (N
o).

[0036] In step 9, the absolute value of the roll angular velocity omega is whether or not ₁ or more and predetermined value omega ₂ below a predetermined value omega is determined. Here, the predetermined value ω ₁ is a threshold value that defines an area where the roll urgency is small. For example, if the current roll angular velocity is ω, after a lapse of a predetermined time, the roll angle at which there is a risk of vehicle rollover It is set to a value that is estimated not to be θ. Then, step 10 if the absolute value is a predetermined value omega ₁ or more and predetermined value omega ₂ than the roll angular velocity omega
(Yes), it is determined that the roll urgency is medium. On the other hand, if the absolute value of the roll angular velocity ω is less than ω ₁ (if the absolute value of the roll angular velocity ω is larger than the predetermined value ω ₂ , the determination is made in step 7), the process proceeds to step 11 (No), and the roll urgency is set. Is determined to be small.

Note that in steps 7 to 11
A series of processing corresponds to the urgency determination means according to claim 1.
You. Step 12 where the roll urgency is determined to be large
Then, the average roll angle θ_{av e}Is the threshold θ_ThreeAnd correction
Value Δθ_ThreeIt is determined whether or not the sum is larger than. This
Here, the correction value Δθ_ThreeIs the alarm timing selection switch 2
Change the alarm generation timing according to the setting state of 0
For example, early A, normal B or late C are selected.
When selected, a negative predetermined value, 0 or a positive predetermined value, respectively.
(A correction value Δθ described later)_TwoAnd Δθ₁But the same
Mr). And the average roll angle θ_aveIs the threshold θ_Three
And correction value Δθ_ThreeIf it is larger than the addition value of step 15
To (Yes), the average roll angle θ_aveIs the absolute value of
Threshold θ_ThreeAnd correction value Δθ_ThreeIf the value is less than or equal to
(No).

When the roll urgency is determined to be medium,
In step 13, the average roll angle θ_{av e}The absolute value of
θ_TwoAnd correction value Δθ_TwoIs greater than the sum of
It is. And the average roll angle θ_aveIs the threshold θ_Two
And correction value Δθ_TwoIf it is larger than the addition value of step 15
To (Yes), the average roll angle θ_aveIs the absolute value of
Threshold θ_TwoAnd correction value Δθ_TwoIf the value is less than or equal to
(No).

If the roll urgency is determined to be small,
In Step 14, the average roll angle θ_{av e}The absolute value of
θ₁And correction value Δθ₁Is greater than the sum of
It is. And the average roll angle θ_aveIs the threshold θ₁
And correction value Δθ₁If it is larger than the addition value of step 15
To (Yes), the average roll angle θ_aveIs the absolute value of
Threshold θ₁And correction value Δθ₁If the value is less than or equal to
(No).

Note that a series of processes in steps 12 to 14 correspond to danger determining means. In step 15, it is determined that there is a danger of the vehicle rolling over, and the warning lamp attached to the roll indicator 18 is turned on. In step 16, the alarm 22 is activated to notify the driver of the risk of the vehicle rolling over by voice. Note that the process of activating the warning light and the alarm 22 in Steps 15 and 16 corresponds to the warning generating means.

In step 17, the average roll angle θ _ave
Is larger than the sum of the threshold values θ _{1 to} θ ₃ corresponding to the roll urgency and the increment Δθ. Here, the increment Δθ is a correction value for determining whether or not to execute the deceleration control in order to reduce the danger of the vehicle rollover to some extent, and is set to a predetermined value having a positive value, for example. Is done. The increment Δθ may be changed according to the roll urgency.

In step 18, a fuel supply amount reduction command or a brake operation command is transmitted to the engine controller 28 and / or the brake controller 30, and deceleration control for reducing the vehicle speed is performed. Step 1
The processing in 8 corresponds to the vehicle deceleration means, the brake operation means, and the fuel reduction means. Step 1 described above
According to the process of step 18, based on the detected vehicle height H _L and H _R at predetermined sampling intervals, the roll angle θ of the vehicle is calculated. Then, a moving average of several to several tens of roll angles θ is calculated, and this is average roll angle θ.
_ave . For this reason, for example, even when a fine vibration due to unevenness of the road surface is detected, the moving average is calculated and smoothed, so that unnecessary sensitivity that causes a malfunction can be eliminated.

The average roll angle θ_aveWhere the absolute value of
Constant value θ₀When it is larger, it depends on the roll acceleration ω
Roll urgency is determined. Roll emergency, vehicle rollover
Is a measure of the magnitude of the risk of
Accuracy of rollover danger judgment by dividing the judgment process of
Can be improved. And for each roll urgency
In order to determine the risk of vehicle rollover, the average roll angle θ
_aveIs the threshold θ₁~ Θ _ThreeAnd correction value Δθ₁~ Δθ_ThreeWith
It is determined whether the value is greater than the sum.
The warning light attached to the roll indicator 18 and
The control of the alarm 22 is performed.

At this time, the threshold values θ _{1 to} θ ₃ for judging the danger of the vehicle rolling over are variably set according to the setting state of the parameter setting switch 20, so that various fixed characteristics differ with one hardware. Of vehicles. For this reason, versatility is given to the rollover prevention device, hardware can be shared, and for example, transfer to another vehicle becomes possible. In addition, since a variable characteristic that changes according to the vehicle operation state is also taken into account, a warning can be issued at an optimal timing suitable for the vehicle.

And, through such actions and effects,
Optimizing the timing while adding versatility to the hardware
Warning of danger of vehicle overturning,
Performance can be improved. In addition, for the driver
Even if a warning is issued, the average roll angle θ
_aveWhen the absolute value of
The deceleration control is executed to perform the deceleration control. This causes a warning
Driver does not perform danger avoidance operations
Roll angle decreases through deceleration even when
And reduce the risk of vehicle rollover to some extent
You.

FIG. 6 shows another embodiment of the control contents repeatedly executed at predetermined time intervals in the control unit 26. The description of the same control contents as those shown in FIGS. 3 and 4 is omitted. In step 21 in which the absolute value of the average roll angle θ _ave is determined to be larger than the predetermined value θ ₀ , the roll angle after the lapse of a predetermined time t [sec] (hereinafter referred to as “estimated roll angle”)
θ ′ is calculated. Here, the predetermined time t is a time corresponding to the roll angular velocity ω, and is set, for example, to decrease as the roll angular velocity ω increases. The estimated roll angle θ ′ is, for example, θ ′ based on the average roll angle θ _ave and the roll angular velocity ω representing the roll change state.
= Θ _ave + ω × t.

Further, instead of the roll angular velocity ω, a roll angular acceleration α [rad / sec ² ] representing a roll change state is used, and for example, an arithmetic expression of θ ′ = θ _ave + (α × t ² ) / 2 is used. The calculation may be performed. In this case, by using the roll angular acceleration α, the change state of the roll angular velocity ω can be grasped, and the estimation accuracy can be further improved.
Note that the processing in step 21 corresponds to the roll angle estimating means. The processing for calculating the roll angular velocity ω or the roll angular acceleration α corresponds to the roll change state detecting means.

[0048] At step 22, the estimated roll angle theta 'absolute value of a predetermined value theta' or not ₂ greater than is determined.
Here, the predetermined value θ ′ ₂ is a threshold value that defines an area where the degree of roll urgency is large, and is set, for example, to a value that increases the risk of the vehicle rolling over. If the absolute value of the estimated roll angle θ ′ is larger than the predetermined value θ ′ ₂ , the process proceeds to step 23 (Yes), and it is determined that the roll urgency is large.
On the other hand, if the absolute value of the estimated roll angle θ ′ is equal to or smaller than the predetermined value θ ′ ₂ , the process proceeds to step 24 (No).

[0049] At step 24, the estimated roll angle theta 'absolute value of a predetermined value theta' whether it is ₁ or more and predetermined value theta _'2 or less is determined. Here, the predetermined value θ ′ ₁ is a threshold value that defines an area in which the roll urgency is small, and is set, for example, to a value in which the danger of vehicle rollover is small. The estimated roll angle theta 'absolute value of the predetermined value theta' is determined to be advanced in (Yes), during a roll urgency to step 25 if ₁ or more and predetermined value theta _'2 or less. On the other hand, if the absolute value of the estimated roll angle θ ′ is less than the predetermined value θ ′ ₁ (if the absolute value of the estimated roll angle θ ′ is larger than the predetermined value θ ′ ₂ , the determination is made in step 22), and the process proceeds to step 26. Advance (N
o), it is determined that the roll urgency is small.

The series of processing in steps 22 to 26 corresponds to the urgency determining means according to the second aspect. According to the processing of steps 21 to 26 described above, the estimated roll angle θ ′ after the lapse of the predetermined time t is calculated based on the current roll angular velocity ω. Then, based on the calculated estimated roll angle θ ′, it is determined whether the roll urgency is large, medium or small. For this reason, a warning is issued at a more optimal timing before the actual roll angle becomes the rollover danger angle, and the driver can perform the danger avoidance operation with plenty of time and improve the safety of vehicle operation. It can be further improved.

The vehicle height sensors 16L and 16R may detect the vehicle height of the front shaft on the left and right sides of the vehicle.
In this case, since the roll of the vehicle is started from the front shaft to which the steered wheels are connected, the roll state is predicted earlier. Then, the warning can be given to the driver with a margin, so that the safety can be further improved. When it is determined that the danger of the vehicle rolling over is large, as shown in FIG. 7, the auxiliary wheels 32L and 32R (roll angle limiting means) mounted on the left and right sides of the vehicle are operated to set the roll angle θ. It may be mechanically limited so that the roll angle θ is equal to or less than the limit value.

[0052]

As described above, according to the first or second aspect of the present invention, while giving versatility to hardware, a warning is issued at an optimal timing suitable for vehicle characteristics, Safety in vehicle operation can be improved. According to the third aspect of the present invention, the roll state of the vehicle is predicted with high accuracy by a simple arithmetic expression, and a warning can be issued at an appropriate timing.

According to the fourth aspect of the present invention, since a variable characteristic that changes in accordance with the operating state of the vehicle is taken into consideration, a warning can be issued at a more optimal timing suitable for the vehicle. According to the fifth aspect of the invention, for example, even if a fine vibration due to unevenness of the road surface is detected, it is smoothed by calculating a moving average, and it is possible to prevent an inappropriate warning from being issued.

According to the sixth aspect of the present invention, the roll angle becomes smaller due to the deceleration of the vehicle, so that the danger of the vehicle rolling over can be reduced even if the danger avoidance operation by the driver is delayed. According to the seventh aspect of the invention, for example, the vehicle can be decelerated only by transmitting a control command to the brake controller and / or the engine controller, thereby preventing the control content from becoming complicated.

According to the eighth aspect of the present invention, the roll angle of the vehicle is reliably prevented from exceeding the critical angle, so that it is possible to effectively prevent the vehicle from rolling over.

[Brief description of the drawings]

FIG. 1 is a configuration diagram in which a rollover prevention device according to the present invention is applied to a tractor.

FIG. 2 is an explanatory diagram of each function realized by a control unit.

FIG. 3 is a flowchart showing an example of control contents.

FIG. 4 is a flowchart showing an example of control contents.

FIG. 5 is an explanatory diagram showing a calculation method of a roll angle.

FIG. 6 is a flowchart showing another example of control contents.

FIG. 7 is an explanatory view of an auxiliary wheel for setting a roll angle to a limit value or less.

[Explanation of symbols]

 16L, 16R Vehicle height sensor 18 Roll indicator 22 Alarm 24 Parameter setting switch 26 Control unit 26a Roll angle calculation unit 26b Roll angular speed calculation unit 26c Roll urgency determination unit 26d Threshold setting unit 26e Rollover danger determination unit 26f Indicator control unit 26g Alarm control unit 26h Deceleration control unit 28 Engine controller 30 Brake controller 32L, 32R Auxiliary wheel

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) F02D 29/02 F02D 29/02 K 311 311F F-term (Reference) 3D046 AA04 BB01 BB17 GG02 HH21 HH27 JJ01 MM34 3G093 BA04 BA07 BA24 DB00 DB21 EA05 EB04 FA11 FB02

Claims (8)

[Claims] 1. A roll angle detecting means for detecting a roll angle of a vehicle, a roll angular velocity detecting means for detecting a roll angular velocity of a vehicle, an urgency determining means for determining an urgency corresponding to the detected roll angular velocity, Parameter setting means for variably setting parameters indicating vehicle characteristics; and threshold setting means for setting a threshold for determining a risk of vehicle rollover corresponding to the degree of urgency based on the set parameters. When the absolute value of the roll angle is larger than a threshold value set in accordance with the degree of urgency, there is a danger determining means for determining that there is a danger of a vehicle rollover, and there is a danger of a vehicle rollover by the danger determination means. And a warning issuing means for issuing a warning to the driver when it is determined that: 2. A roll angle detection means for detecting a roll angle of a vehicle, a roll change state detection means for detecting a roll change state of a vehicle, and a roll angle and a roll change state detected.
Roll angle estimating means for estimating the roll angle of the vehicle after a predetermined time has elapsed; urgency determining means for judging the urgency according to the estimated roll angle; parameter setting for variably setting parameters indicating vehicle characteristics Means, a threshold setting means for setting a threshold for determining a risk of vehicle rollover corresponding to the urgency based on the set parameters, and an absolute value of the detected roll angle corresponds to the urgency. Danger determining means for determining that there is a danger of a vehicle rollover when the danger of the vehicle rollover is determined by the danger determining means; A rollover prevention device for a vehicle, comprising: warning generation means for generating a warning. 3. The apparatus according to claim 2, wherein said roll change state detecting means detects a roll angular velocity or a roll angular acceleration as a roll state of the vehicle. 4. The apparatus according to claim 1, wherein said parameter setting means sets a fixed characteristic peculiar to the vehicle and a variable characteristic dynamically changing according to a vehicle operation state. The rollover prevention device for a vehicle according to any one of the preceding claims. 5. A vehicle height detecting means for detecting a vehicle height on the left and right sides of the vehicle; a roll angle calculating means for calculating a roll angle based on the detected vehicle height; and a moving average of the calculated roll angles. A moving average calculating unit that performs a moving average calculation, wherein the roll angle detecting unit sets a moving average of the calculated roll angles as a roll angle.
The vehicle rollover prevention device according to claim 4. 6. A vehicle deceleration means for decelerating a vehicle when the danger determination means determines that there is a danger of vehicle rollover. The rollover prevention device for a vehicle according to any one of the first to third aspects. 7. The vehicle deceleration means according to claim 6, wherein said vehicle deceleration means is at least one of a brake operation means for operating a brake of the vehicle and a fuel reduction means for reducing fuel supplied to an engine. Vehicle rollover prevention device. 8. A roll angle limiting means for mechanically limiting a roll angle of the vehicle when the danger determining means determines that there is a danger of rollover of the vehicle. The rollover prevention device for a vehicle according to claim 7.