JP2005104298A - Occupant protecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an occupant protecting device capable of protecting an occupant sufficiently by actuating an occupant protector properly even if the accident having occurred is in complicated rollover form or such as having a secondary factor. <P>SOLUTION: The occupant protecting device includes the occupant protector to be actuated for protecting the occupant when a vehicle has made rollover, and is equipped with a rollover angle sensor (rollover angular velocity sensing means) 1 to sense the rollover angular velocity at the time the vehicle has made rollover and a rollover judging module (rollover judging means) 4 to judge whether the rollover possibility exists and the rollover form of the vehicle on the basis of the rollover angular velocity sensed by the sensor 1 and the rollover angle determined from the rollover angular velocity, wherein the occupant protector is actuated when the sensor 1 has sensed a rollover angular velocity equal to or exceeding a certain value decided any arbitrarily. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an occupant protection device that operates an occupant protection device to protect an occupant from an impact when the vehicle rolls over.

  Conventionally, when a vehicle rolls over, an occupant protection device that activates occupant protection devices such as a curtain airbag, a seat belt pretensioner, and an active rollover to protect the occupant from the impact caused by the rollover of the vehicle is known. (For example, refer to Patent Document 1).

  In this conventional occupant protection device, whether or not a rollover has occurred is determined based on whether or not the actual rotation angular velocity of the vehicle is greater than a predefined rollover determination rotation angle for determining rollover. When it is determined, only the occupant protection device on the rollover side is controlled to operate.

Then, after the occupant protection device arranged on the rollover side is activated, whether the actual rotation angular velocity of the vehicle is larger than the rotation determination rotational angular velocity for determining the predetermined rolling is determined. The presence or absence of occurrence is determined, and when it is determined that the vehicle rolls, an occupant protection device arranged on the non-rollover side is further activated.
Japanese Patent Laid-Open No. 2002-200962

  By the way, in the above-mentioned occupant protection device, first, whether or not rollover has occurred is determined and only the rollover-side occupant protection device is operated, and then whether or not rolling has occurred is determined and the non-rollover-side occupant protection device is operated. ing. For this reason, in the case of a rollover that rotates multiple times or an accident with a secondary factor that touches the surrounding obstacles after the vehicle suddenly rolls over, the operation of the occupant protection device on the non-rollover side is delayed, impacting the occupant There was a risk that it could not be adequately protected from.

  The present invention has been made in view of the above problems, and even if it is a complicated roll-up form that rotates a plurality of times or an accident that has secondary factors such as contact with surrounding obstacles, an occupant protection device It is an object of the present invention to provide an occupant protection device capable of sufficiently operating the occupant and sufficiently protecting the occupant.

  In order to solve the above-described problem, the occupant protection device according to claim 1 includes an occupant protection device that operates when the vehicle rolls over to protect the occupant, and detects the rollover angular velocity when the vehicle rolls over. A rollover angular velocity comprising angular velocity detection means, rollover angular velocity detected by the rollover angular velocity detection means, and the rollover determination means for judging whether or not the vehicle rolls over and on the basis of the rollover angle obtained from the rollover angular velocity. The occupant protection device is activated when the detection means detects a rollover angular velocity equal to or greater than a predetermined value.

  According to the first aspect of the present invention, the occupant protection device is activated when the rollover angular velocity detection means detects a rollover angular velocity that is not less than a predetermined value. It becomes possible to operate reliably.

  And even if it is an accident etc. which have a complicated rollover form or a secondary factor, the operation | movement of a passenger | crew protective device is no longer delayed and a passenger | crew can be protected reliably.

  According to a second aspect of the present invention, in the occupant protection device according to the first aspect, the occupant protection device disposed on the rollover side and the non-rollover side when the rollover determination means determines that the rollover mode maintains the rollover angular velocity. It is characterized by operating.

  According to the invention of claim 2, in addition to the effect of claim 1, when the rollover judging means judges that the rollover form in which the rollover angular velocity is sustained, the occupant protection device arranged on the rollover side and the non-rollover side operates. The vehicle state can be grasped more accurately, and the occupant protection device can be actuated quickly. And a passenger | crew can fully be protected from the impact of rollover.

  The invention according to claim 3 is the occupant protection device according to claim 1 or 2, wherein when the rollover determining means determines that the rollover mode does not maintain the rollover angular velocity, only the occupant protection device disposed on the rollover side is provided. It is characterized by operating.

  The invention according to claim 3 is the occupant protection device according to claim 1 or 2, wherein only the occupant protection device arranged on the rollover side operates when the rollover judging means judges that the rollover mode does not maintain the rollover angular velocity. As a result, the occupant protection device is not operated unnecessarily. And it can prevent that the passenger | crew protective device which act | operated unnecessary touches a passenger | crew, or repairs the passenger | crew protective device which act | operated unnecessary.

  According to a fourth aspect of the present invention, in the occupant protection device according to any one of the first to third aspects, the rollover judging means is obtained from the rollover angular velocity detected by the rollover angular velocity detecting means and the rollover angular velocity. It is characterized by having rolling determination means for determining whether or not the rollover angular velocity is persistent based on the rollover angle and for determining whether or not the vehicle is capable of rolling based on the presence or absence of the rollover angular velocity. Yes.

  According to the fourth aspect of the invention, in addition to the effects of the first to third aspects, the rollover judging means includes the rolling judgment means for judging whether or not the rollover angular velocity is persistent and whether or not the rollover is possible. It is possible to more accurately determine the rollover mode of the vehicle based on the angular velocity, and it is possible to improve the accuracy of determining the possibility of rolling.

  According to a fifth aspect of the present invention, in the occupant protection device according to any one of the first to fourth aspects, the rollover judging means is configured when the vehicle rolls over based on the rollover angular speed detected by the rollover angular speed detecting means. It has energy calculating means for calculating kinetic energy and potential energy, and determines whether or not the vehicle rolls over and rolls over based on the kinetic energy and potential energy calculated by the energy calculating means, and this roll judging means When the vehicle is determined to be in a rollover mode in which kinetic energy is maintained, the occupant protection device arranged on the rollover side and the non-rollover side is actuated.

  According to the invention of claim 5, in addition to the effects of claims 1 to 4, when the rollover judging means judges that the rollover mode has sustained kinetic energy, the occupant protection device disposed on the rollover side and the non-rollover side is activated. Therefore, even in an accident with a complicated rollover form or a secondary factor, the state of the vehicle can be accurately grasped, and the operation of the occupant protection device is not delayed, so that the occupant is reliably protected. be able to.

  In the occupant protection device according to claim 5, when the rollover judging means judges that the rollover mode does not maintain kinetic energy, only the occupant protection device arranged on the rollover side is operated. It is characterized by that.

  According to the sixth aspect of the invention, in addition to the effect of the fifth aspect, only the occupant protection device arranged on the rollover side operates when the rollover judging means judges that the rollover mode does not maintain kinetic energy. The tool is not operated unnecessarily. And it can prevent that the passenger | crew protective device which act | operated unnecessary touches a passenger | crew, or repairs the passenger | crew protective device which act | operated unnecessary.

  According to a seventh aspect of the present invention, in the occupant protection device according to the fifth or sixth aspect, the rollover judging means determines whether or not the kinetic energy is persistent based on the kinetic energy and the potential energy calculated by the energy calculating means. It is characterized by having a rolling determination means for determining whether or not the vehicle is capable of rolling based on the determination of whether or not the kinetic energy is persistent.

  According to the seventh aspect of the invention, in addition to the effect of the fifth or sixth aspect, the rollover judging means includes the rolling judgment means for judging the presence / absence of kinetic energy and the possibility of rolling. It is possible to more accurately determine the rollover mode of the vehicle based on energy, and it is possible to improve the accuracy of determining the possibility of rolling.

  According to an eighth aspect of the present invention, in the occupant protection device according to any one of the first to seventh aspects of the present invention, the occupant protection device includes a protective device control means for controlling the operation of the occupant protective device.

  According to the eighth aspect of the invention, in addition to the effects of the first to seventh aspects, since the protective device control means for controlling the operation of the occupant protection device is provided, the occupant protection device can be controlled accurately and easily. Can do. And when a vehicle rolls over, a passenger | crew can fully be protected according to the rollover form.

  According to the present invention, it is possible to provide an occupant protection device that can sufficiently protect an occupant by accurately operating an occupant protection device even in an accident having a complicated rollover form or a secondary factor. Can do.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 shows the overall configuration of an occupant protection device to which the present invention is applied. This occupant protection device has occupant protection devices such as curtain airbags, seat belt pretensioners, and active roll bars, and determines whether or not the vehicle rolls over. The protective equipment is operated to protect the occupant from the impact generated when the vehicle rolls over.

  Then, as shown in FIG. 1, a rollover angle sensor (rollover angular velocity detection means) 1, a rollover G sensor 2, an EEPROM 3, a rollover determination module (rollover determination means) 4, an inclination sensor 5, an occupant protection device operating unit (protection device control) Means) 6 and the like.

  The rollover angle sensor 1 detects an angular velocity (rollover angular velocity) of the rollover (rotation) of the vehicle around an axis extending through the center of gravity of the vehicle and extending in the front-rear direction of the vehicle. The output signal (angular velocity signal) from the rollover angle sensor 1 is filtered by a high frequency noise removal filter (LPF: Low Pass Filter) 7, then AD converted by an A / D converter 8, and input to the rollover determination module 4. The

  The lateral G sensor 2 detects acceleration (lateral G) in the vehicle width direction of the vehicle. The output signal from the lateral G sensor (lateral G signal) is filtered by a high frequency noise removal filter (LPF: Low Pass Filter) 9, then AD converted by an A / D converter 10, and input to the rollover determination module 4. The

  The EEPROM 3 stores vehicle structure parameters described later in advance. The vehicle structure parameters stored in the EEPROM 3 are input to the rollover determination module 4.

  The rollover determination module 4 includes an angle calculation device 11, an energy calculation device 12, a threshold value correction device 13, and a vehicle state determination device 14.

  The angle detection device 11 integrates the angular velocity signal obtained from the rollover angle sensor 1 to obtain the rollover angle, and an output signal (angle signal) from the angle detection device 11 is input to the vehicle state determination device 14. .

  The energy calculation measure 12 includes a kinetic energy calculation device 15 and a potential energy calculation device 16, and based on the angular velocity signal obtained from the rollover angle sensor 1 and the vehicle structure parameter obtained from the EEPROM 3, respectively, Is calculated. The output signals (kinetic energy signal, potential energy signal) from the kinetic energy calculation device 15 and the potential energy calculation device 16 are input to the vehicle state determination device 14.

  The threshold correction device 13 includes a deceleration G determination device 17 and a corrector 18, and when the deceleration G determination device 17 determines that the vehicle lateral deceleration G has suddenly changed, as will be described later. The corrector 18 corrects the rollover threshold line for rollover determination or the rolling threshold line for roll determination. An output signal (correction signal) from the corrector 18 is input to the vehicle state determination device 14.

  The vehicle state determination device 14 includes a rollover determination unit 19 and a roll determination unit (rolling determination unit) 20. The vehicle state determination unit 14 determines whether or not the vehicle rolls over, whether the vehicle rolls over, and whether the vehicle rolls. Judgment. An output signal (rollover determination signal) from the vehicle state determination device 14 is input to an AND circuit 23 described later.

  The rollover judging unit 19 is preliminarily determined in advance from an angular velocity signal obtained from the rollover angle sensor 1, an angle signal calculated from the angle detection device 11, and a kinetic energy signal and a potential energy signal calculated from the energy calculation device 12. Set the rollover threshold line.

  Then, the rollover determination unit 19 compares the rollover threshold line with the actual rollover angular velocity or kinetic energy of the vehicle, and determines the presence or absence of the rollover possibility and the rollover mode of the vehicle.

  Further, the rolling determination unit 20 uses the angular velocity signal obtained from the rollover angle sensor 1 and the angle signal calculated from the angle calculation device 12 or the kinetic energy signal and the potential energy signal calculated from the energy calculation device 12. A predetermined rolling threshold line is set in advance.

  The rolling determination unit 20 compares the rolling threshold line with the actual rollover angular velocity or kinetic energy of the vehicle, determines whether the rollover angular velocity is persistent, and determines whether the kinetic energy is persistent. judge.

  Furthermore, in this rolling determination part 20, while determining the presence or absence of a rolling possibility based on the presence or absence of the rollover angular velocity, the presence or absence of a rolling possibility is determined based on the presence or absence of the persistence of kinetic energy. .

  The tilt sensor 5 determines the tilt state of the vehicle and outputs an ON signal when the vehicle is tilting. The output signal from the tilt sensor 5 is filtered by a high frequency noise removal filter (LPF: Low Pass Filter) 21, converted into a tilt signal by the tilt determination block 22, and input to the AND circuit 23.

  The AND circuit 23 outputs an operation signal to the occupant protection device operation unit 6 when an AND condition between the rollover determination signal from the vehicle state determination device 14 and the vehicle inclination signal from the inclination determination block 22 is satisfied.

  The occupant protection device actuating unit 6 is configured to detect occupant protection devices such as a curtain airbag, a seat belt pretensioner, and an active roll bar disposed on the vehicle based on the rollover determination signal and the vehicle tilt signal input from the AND circuit 23. Among them, the one arranged at an appropriate site is operated.

  Next, a specific method for determining whether or not there is a possibility of rollover in the rollover determination module 4 will be described.

  The rollover of the vehicle when the two wheels on one side of the vehicle are fixed shafts (the friction coefficient between the wheels and the road surface is infinite) is considered based on the vehicle rollover model of FIG.

In FIG. 2, OG is the position of the center of gravity of the vehicle S, H is the height of the center of gravity of the vehicle S, L is the distance from the wheel contact surface to the position of the center of gravity, W is the tread width, M is the vehicle weight, and g is the gravitational acceleration (9.8 m / SEC ² ).

  Further, Φ is a rollover angle obtained from an integral value (∫Φdt) of the angular velocity signal (deg / sec) obtained from the rollover angle sensor 1, and ΦO is an angle obtained by subtracting SSA (Static Stability Angle) from 90 ° (90 -Arctan ((W / 2) / H)).

  SSA indicates the rollover angle Φ when the position of the center of gravity (OG) of the vehicle S is the highest, and is represented by arctan ((W / 2) / H).

  The judgment of the possibility of rollover is based on the rollover angle Φ that indicates the current rollover state of the vehicle and the rollover acceleration Φ ′ that is an index of kinetic energy that indicates how much rotation can be sustained against gravity. It is done.

  If the rollover angle in a horizontal state (the vehicle is on a flat road surface) is 0 °, the vehicle starts to roll over, and the rollover angle becomes 0 ° to SSA (position where the center of gravity (OG) is the highest). Until then, gravity works to suppress rollover. When the rollover angle exceeds SSA, gravity works in a direction to accelerate rollover. Thus, it is considered that the vehicle basically rolls over if the roll angle of the vehicle exceeds SSA.

  Further, since this rollover motion rotates around a fixed axis, energy loss due to friction with the road surface can be almost ignored. Therefore, since there is no exchange of energy other than gravity, the state of the vehicle can be expressed by the equation of potential energy and kinetic energy.

The position energy X of the current center of gravity that moves as the vehicle rolls over is obtained by the following equation (1).
X = Mg (Lsin [ΦO + Φ] −H) (1)
Further, the kinetic energy Y accompanying the rollover of the vehicle is obtained by the following equation (2).
Y = 1/2 (IO + ML ² ) ω ² (2)
Here, IO is the moment of inertia around the center of gravity, and ω is a value obtained by replacing the angular velocity signal (deg / sec) obtained from the rollover angle sensor 1 in units of rad / sec.

  Among the parameters necessary for the calculation by the above formulas (1) and (2), the moment of inertia IO around the center of gravity, the vehicle weight M, the distance L from the wheel contact surface to the center of gravity position, and the center of gravity height H of the vehicle are as follows. The value is determined in advance and is different for each vehicle.

  Therefore, different values for each vehicle are stored in the EEPROM 3 as vehicle structure parameters. The energy calculation device 12 calculates kinetic energy and potential energy associated with rotation of the vehicle that is rolling over by using these vehicle structure parameters.

  Then, the rollover determination unit 19 determines whether or not the calculated kinetic energy and potential energy are necessary for rollover of the vehicle, thereby determining whether the vehicle is likely to rollover.

The energy required for the vehicle to roll over is obtained by the following equation (3).
1/2 (IO + ML ² ) ω ² + Mg (Lsin [ΦO + Φ] −H) = Mg (L−H) (3)
This is derived from the law of conservation of energy 1/2 (IO + ML ² ) ω ² + Mg (Lsin [ΦO + Φ]) = MgL
Is obtained by subtracting the horizontal position energy MgH so that the position energy when the vehicle is horizontal becomes zero.

  Here, the height of the center of gravity from the ground is represented as h [Φ] = LSin [ΦO + Φ]. The highest point of the center of gravity (OG) is h [SSA] = L when Φ = SSA, and the vehicle is horizontal. The height of the center of gravity at that time is h [0] = H.

In the above formula (3), 1/2 (IO + ML ² ) ω ² is the kinetic energy Y accompanying the rotation of the vehicle, and Mg (Lsin [ΦO + Φ] −H) is the potential energy of the center of gravity that moves with the rotation of the vehicle. X. When each is replaced by X and Y, the following equation (4) is obtained.
Y = −X + Mg (L−H) (4)
Therefore, when the above equation (4) is plotted on a graph with the potential energy (Nm ^1/2 ) as the X axis and the kinetic energy (Nm ^1/2 ) and the rollover angular velocity (dig / sec) as the Y axis, FIG. Thus, a rollover threshold line A that is a reference for vehicle rollover determination is obtained.

  Even when the above formula (4) is plotted on a graph in which the rollover angle (deg) is the X axis and the rollover angular velocity (dig / sec) is the Y axis, the rollover threshold line A serving as a reference for the rollover determination is obtained. Can be obtained.

  In a state where the friction coefficient between the wheel and the road surface is considered to be infinite, in principle, when the kinetic energy accompanying the rotation of the vehicle and the positional energy of the center of gravity moving by the rotation exceed this rollover threshold line A Alternatively, when the rollover angular velocity and rollover angle of the vehicle exceed the rollover threshold line A, it can be determined that the vehicle rolls over (CASEα and CASEβ in FIG. 3).

  On the other hand, when the kinetic energy associated with the rotation of the vehicle and the positional energy of the center of gravity moved by the rotation do not exceed the rollover threshold line A, or the rollover angular velocity and rollover angle of the vehicle do not exceed the rollover threshold line A Then, it can be determined that the vehicle does not roll over (CASEγ and CASEδ in FIG. 3).

  Note that Mg (LH) is a fixed value determined by the vehicle structure parameter, and by reading the vehicle structure parameter stored in the EEPROM 3, the rollover threshold line A for rollover determination in the vehicle is determined. .

  However, when the rollover angle sensor 1 detects a rollover angular velocity equal to or greater than a predetermined value indicated by the roll threshold line B in FIG. 3, that is, when the rollover angular velocity of the vehicle exceeds the roll threshold line B (FIG. 3, CASEα) determines that the rollover determination unit 19 has the possibility of rollover regardless of the kinetic energy and position energy of the vehicle.

  Then, when a rollover determination signal is output from the vehicle state determination device 14 and an AND condition with the vehicle inclination signal from the inclination determination block 22 is satisfied in the AND circuit, the occupant protection device is operated by the occupant protection device operation unit 6.

  As a result, it is possible to accurately operate the occupant protection device even when the vehicle rolls over at a high rotational speed, and the vehicle condition can be accurately determined even in an accident with a complicated rollover configuration or secondary factors. Can grasp. Then, the operation of the occupant protection device is not delayed, and the occupant can be reliably protected.

  Further, since the operation of the occupant protection device is controlled by the occupant protection device operation unit 6, the occupant protection device can be controlled accurately and easily. And when a vehicle rolls over, it becomes possible to actuate a suitable passenger protective device according to the roll-over form, and to protect a passenger | crew reliably.

  Next, a specific method for determining whether or not a vehicle rolls over and whether or not it rolls will be described.

  First, a predetermined roll angular velocity or kinetic energy value is set in advance (indicated by a rolling threshold line B in FIG. 3).

  In a state where the friction coefficient between the wheel and the road surface is considered to be infinite, in principle, when the kinetic energy accompanying the rotation of the vehicle or the rollover angular velocity of the vehicle exceeds this rolling threshold line B, the kinetic energy In addition, it is determined that the rollover configuration is such that the rollover angular velocity is sustained, and it can be determined that the vehicle rolls (CASEα in FIG. 3).

  As described above, when it is determined that the tumbling configuration in which the kinetic energy and the rollover angular velocity are sustained, the vehicle state determination device 14 outputs a rollover determination signal having the possibility of rolling, and the AND circuit determines the inclination determination block 22. When the AND condition with the vehicle inclination signal from is established, the occupant protection device is operated by the occupant protection device operation unit 6. At this time, the occupant protection devices arranged on the rollover side and the non-rollover side of the vehicle are activated.

  Thereby, the state of the vehicle can be grasped more accurately, and the occupant protection device can be operated quickly. And it becomes possible to fully protect a passenger | crew from the impact of rollover.

  On the other hand, if the kinetic energy accompanying the rotation of the vehicle or the rollover angular velocity of the vehicle does not exceed this rolling threshold line B, it is determined that the kinetic energy and the rollover angular velocity are in a rollover mode that does not last, and it is determined that the vehicle does not roll. (CASEβ in FIG. 3).

  As described above, when it is determined that the tumbling configuration does not maintain the kinetic energy and the rollover angular velocity, the vehicle state determination device 14 outputs a rollover determination signal having no possibility of rolling, and the AND circuit determines the inclination. When the AND condition with the vehicle tilt signal from the block 22 is established, the occupant protection device is operated by the occupant protection device operation unit 6. At this time, only the occupant protection device arranged on the rollover side of the vehicle operates.

  As a result, the passenger protective equipment is not operated unnecessarily. And it can prevent that the passenger | crew protective device which act | operated unnecessary touches a passenger | crew, or repairs the passenger | crew protective device which act | operated unnecessary.

  The above has considered the case where the two wheels on one side of the vehicle are fixed shafts (the friction coefficient between the axle and the road surface is infinite), but the wheels slip sideways and the friction coefficient between the wheels and the road surface is zero. The same idea holds for cases.

In this case, the current position energy X of the center of gravity that moves as the vehicle rolls over is obtained by the above equation (1) as described above. On the other hand, the kinetic energy associated with the rollover of the vehicle is obtained by the following equation (5).
Y = 1/2 (ML ² cos [ΦO + Φ] ² + IO) ω ² (5)
Further, the energy required for the vehicle to roll over is obtained by the following equation (6) from the above equation (5).
1/2 (ML ² cos [ΦO + Φ] ² + IO) ω ² + Mg (Lsin [ΦO + Φ] −H) = Mg (L−H) (6)
In the above formula (6), ½ (ML ² cos [ΦO + Φ] ² + IO) ω ² is the kinetic energy Y associated with the rotation of the vehicle, and Mg (Lsin [ΦO + Φ] −H) is associated with the rotation of the vehicle. This is the potential energy X of the moving center of gravity.

Therefore, the above formula (6) is expressed on the graph with the potential energy (Nm ^1/2 ) and rollover angle (deg) as the X axis and the kinetic energy (Nm ^1/2 ) and rollover angular velocity (dig / sec) as the Y axis. When plotted, the rollover threshold line A of Y = −X + Mg (L−H) is obtained as described above.

  Even in a state where the friction coefficient between the wheel and the road surface is considered to be zero, in principle, the kinetic energy accompanying the rotation of the vehicle and the positional energy of the center of gravity moving by the rotation exceed the rollover threshold line A. It can be determined that the vehicle rolls over.

  In addition, the determination of the possibility of rolling in a state where the friction coefficient between the wheel and the road surface is considered to be zero is the same as the state where the friction coefficient between the wheel and the road surface is considered to be infinite. Can think.

  As described above, in a state where the friction coefficient between the wheel and the road surface is considered to be infinite or a state where the friction coefficient between the wheel and the road surface is considered to be zero, in principle, the vehicle stored in the EEPROM 3 Whether the vehicle can roll over can be determined using the rollover threshold line A determined based on the structure parameter, and whether the vehicle can roll can be determined using the rolling threshold line B. it can.

  However, in reality, the vehicle weight, the height of the center of gravity, and the like may be slightly changed according to the number of passengers, the load state of the luggage, and the like. In such a case, the rollover threshold line A and the rolling threshold line B may be set in consideration of worst conditions such as the maximum number of occupants and the maximum load weight in advance and taking into account the margin as the amount of energy.

  Furthermore, in actuality, the friction coefficient varies depending on the road surface on which the vehicle travels, and this point needs to be taken into consideration. The friction coefficient between the wheel and the road surface depending on the road surface condition can be indirectly determined from the lateral acceleration (lateral G) acting on the vehicle.

  Therefore, when the vehicle state determination device 14 determines whether or not the vehicle rolls over and rolls over, it depends on the lateral G signal input from the lateral G sensor 2, that is, the occurrence state of the lateral G applied to the vehicle. A correction for increasing or decreasing the equal energy margin is added to each of the threshold lines A and B. Then, the rollover threshold line A ′ and the rolling threshold line B ′ (indicated by broken lines in FIG. 3) are used to determine whether the vehicle can roll over and whether or not it can roll.

  In addition, when correction is applied to the threshold lines A and B determined by the potential energy and the kinetic energy as described above, the ratio of the amount of energy corrected by the positional energy and the kinetic energy should be equal. Therefore, it is possible to easily correct each threshold line A and B by storing information (correction coefficient) such as what percentage margin is increased or decreased according to the occurrence state of the lateral G applied to the vehicle. It becomes.

  The information such as the correction coefficient may be stored in the EEPROM 3 or the like together with the vehicle structure parameters described above by obtaining an optimum margin amount according to the occurrence state of the lateral G in advance through experiments or the like.

  Further, in the vehicle rollover mode, the friction coefficient between the wheel and the road surface may change abruptly, and such a change in the friction coefficient needs to be reflected in the vehicle rollover determination and rolling determination.

  Therefore, when the vehicle state determination device 14 determines whether or not the vehicle rolls and rolls, the deceleration G determination device 17 determines that the vehicle lateral deceleration G has suddenly changed. The corrector 18 corrects the threshold lines A and B according to the degree of change, and uses the corrected threshold lines to determine the possibility of rollover and the possibility of rolling of the vehicle.

  When a specific example is given and explained, the friction coefficient between the wheel and the road surface suddenly increases at the time of the so-called trip system rollover such as the case where the wheel rolls over while sliding, as shown in FIG. Along with this, a large deceleration G may occur.

  On the other hand, as shown in FIG. 5A, the friction coefficient between the wheel and the road surface changes suddenly during the so-called turnover rollover such as when the vehicle rolls over because it travels at a high speed on a sharp curve. There is nothing wrong.

  Also, as shown in FIG. 6 (a), the coefficient of friction between the wheel and the road surface also occurs during a so-called fallover rollover such as when one wheel of a wheel rides on an obstacle or the like, or when the wheel is removed from the side of the road. Does not change rapidly.

  FIG. 4 (b) shows how the vehicle lateral deceleration G occurs when the trip system rolls over, and FIG. 4 (c) shows how the roll angle is generated. As shown in FIGS. 4B and 4C, the rollover angle of the vehicle is small at the point where a large deceleration G occurs during the rollover of the trip system. However, at this point, the vehicle has a sufficient amount of energy to roll over.

Since the rollover angle of the vehicle at the time when the friction coefficient μ between the wheel and the road surface changes abruptly, the vehicle lateral deceleration G at this time is approximately expressed by the following equation (7).
Yhg (vehicle deceleration G) = μRz / M≈μMg / M = μg (7)
Note that Rz is a vertical resistance force and Rz = Mgcos θ, but is almost represented by Mg because the rollover angle θ is very small. For this reason, the friction coefficient μ between the wheel and the road surface is expressed by the following formula (8).
μ = Yhg / g (g: 9.8 m / sec ² ) (8)
On the other hand, FIG. 5B shows how the vehicle lateral deceleration G occurs when the rollover system rolls over, and FIG. 5C shows how the rollover angle occurs when the vehicle rolls over in the fallover system. FIG. 6 (b) shows how the deceleration G is generated, and FIG. 6 (c) shows how the rollover angle is generated.

  As shown in FIGS. 5 (b), 5 (c) and 6 (b), (c), there is no large deceleration G during the rollover of the turnover system and the fallover system. It is considered that the friction coefficient does not increase rapidly. In these cases, the threshold lines A and B may be used without correction.

  In FIGS. 5 (b) and 6 (b), a large deceleration G occurs at time P. At this time, the vehicle has already overturned (the rollover angle is 90 ° or more). This is the impact when the side touches the road surface.

  From the above, in the vehicle state determination device 14, when the deceleration G determination device 17 determines that the vehicle lateral deceleration G has suddenly changed based on the lateral G signal input from the lateral G sensor 2, the wheel It is determined that the coefficient of friction between the road surface and the road surface has changed abruptly, and the use of the threshold lines A and B corrected by the corrector 18 determines the possibility of rollover and whether or not there is a possibility of rolling.

  Here, the correction of each of the threshold lines A and B depends on the degree of change in the deceleration G, that is, the degree of change in the friction coefficient between the wheel and the road surface, as shown in FIGS. 7A and 7B, for example. It is only necessary to divide the level.

  In addition, it is actually necessary to consider the suspension characteristics that are different for each vehicle. In this regard, an equal energy margin as a suspension correction coefficient is added to each of the threshold lines A and B described above. Correction may be performed.

  The suspension correction coefficient, that is, the equi-energy margin amount, includes the inertia moment IO around the center of gravity of the vehicle, the vehicle weight M, the distance L from the wheel contact surface to the center of gravity, the tread width W, the center of gravity height H of the vehicle, and the like. The vehicle structure parameter may be stored in the EEPROM 3 as one of the vehicle structure parameters.

1 is a block diagram showing an overall configuration of an occupant protection device according to the present invention. It is explanatory drawing which shows the rollover model of a vehicle at the time of using 2 wheels on one side of a vehicle as a fixed axis. It is a figure showing the threshold value of vehicle rollover judgment and the threshold value of vehicle rolling judgment in the graph which made the potential energy and rollover angle X-axis, and the kinetic energy and rollover angular velocity were Y-axis. (A) It is explanatory drawing which shows the rolling type of a trip type | system | group. (B) It is a graph which shows the generation | occurrence | production condition of the vehicle lateral direction deceleration G at the time of the roll-over of a trip type | system | group. (C) It is a graph which shows the generation | occurrence | production condition of the rollover angle of the vehicle at the time of the roll of a trip type | system | group. (A) It is explanatory drawing which shows the rollover type of a turnover type | system | group. (B) It is a graph which shows the generation | occurrence | production condition of the vehicle lateral direction deceleration G at the time of rollover of a turnover type | system | group. (C) It is a graph which shows the generation | occurrence | production condition of the rollover angle of the vehicle at the time of a rollover type rollover. (A) It is explanatory drawing which shows the rollover type of a fallover type | system | group. (B) It is a graph which shows the generation | occurrence | production condition of the vehicle lateral direction deceleration G at the time of rollover of a fallover type | system | group. (C) It is a graph which shows the generation | occurrence | production state of the rollover angle of the vehicle at the time of fallover type rollover. (A) It is a table | surface which shows the example of the grade of the correction | amendment of a threshold line. (B) It is the figure which represented on the graph the example of the grade of the correction | amendment of a threshold line.

Explanation of symbols

1 Rollover angular velocity detection means (rollover angle sensor)
4 rollover judging means (rollover judging module)

Claims (8)

An occupant protection device having an occupant protection device that operates when a vehicle rolls over to protect the occupant,
A rollover angular velocity detection means for detecting a rollover angular velocity at the time of the rollover of the vehicle, a rollover angular velocity detected by the rollover angular velocity detection means, and the presence / absence of the rollover possibility of the vehicle based on the rollover angle obtained from the rollover angular velocity, and A rollover judging means for judging the rollover form;
An occupant protection device that activates an occupant protection device when the rollover angular velocity detection means detects a rollover angular velocity that is not less than a predetermined value.   2. The occupant protection device according to claim 1, wherein the occupant protection device disposed on the rollover side and the non-rollover side is actuated when the rollover determination unit determines that the rollover mode maintains the rollover angular velocity. Occupant protection device.   3. The occupant protection device according to claim 1, wherein, when the rollover determining means determines that the rollover mode does not maintain the rollover angular velocity, only the occupant protection device arranged on the rollover side is operated. Crew protection device.   The occupant protection device according to any one of claims 1 to 3, wherein the rollover judging means is a rollover angular velocity based on a rollover angular velocity detected by the rollover angular velocity detecting means and a rollover angle obtained from the rollover angular velocity. An occupant protection device comprising a rolling determination means for determining whether or not the vehicle is capable of rolling based on whether or not the rolling angular velocity is persistent. 5. The occupant protection device according to claim 1, wherein the rollover determination unit calculates kinetic energy and potential energy when the vehicle rolls over based on the rollover angular velocity detected by the rollover angular velocity detection unit. And having energy calculation means for calculating, and determining the presence or absence of rollover and the rollover form of the vehicle based on the kinetic energy and the potential energy calculated by the energy calculation means,
An occupant protection device that activates the occupant protection device disposed on the rollover side and the non-rollover side when the rollover determination means determines that the tumbling mode maintains kinetic energy.   6. The occupant protection device according to claim 5, wherein, when the rollover determining means determines that the rollover mode does not maintain kinetic energy, only the occupant protection device disposed on the rollover side is operated. apparatus.   The occupant protection device according to claim 5 or 6, wherein the rollover judging means judges whether or not the kinetic energy is persistent based on the kinetic energy and the potential energy calculated by the energy calculating means, and the kinetic energy. An occupant protection device comprising a rolling determination means for determining whether or not the vehicle is capable of rolling based on whether or not the vehicle is persistent.   The occupant protection device according to any one of claims 1 to 7, further comprising protective device control means for controlling an operation of the occupant protective device.

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