Vehicle safety system

A vehicle safety system includes an obstacle detecting device for detecting an obstacle around a vehicle; a vehicle state detecting device for detecting states of a speed, acceleration, turning sideways, sudden braking, sudden revolving, sideslipping and the like of the vehicle; a dangerous degree determining device for determining a dangerous level of the obstacle with respect to the vehicle or dangerous level of the vehicle itself by receiving information from the obstacle detecting device and/or the vehicle state detecting device; a seat belt device for changing a shape, including an area of a belt, of a touching portion where the belt touches an occupant according to dangerous level information from the dangerous degree determining device; and an occupant identifying device for storing physical characteristics of the occupant sitting on a seat corresponding to the seat belt device. The seat belt device receives information from the occupant identifying device, and changes the shape of the touching portion according to the physical characteristics of the occupant on the seat. Thus, the vehicle safety system provides the occupant with a warning and more suitable protection by estimating a dangerous degree of the obstacle or problem.

BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT
 The invention relates to a vehicle safety system for recognizing an
 obstacle or problem around a vehicle or about the vehicle itself and
 estimating a dangerous degree of the obstacle and problem to thereby
 provide an occupant in the vehicle with a warning or protection.
 Recently, there has been developed a collision preventing device wherein an
 obstacle, such as a car, running in front of a vehicle is detected by a
 radar device or the like; a warning is given to a driver of the vehicle by
 estimating a collision of the obstacle with the vehicle; or a braking
 device is operated to lower a speed of the vehicle. As a device for
 providing the driver with the warning, a warning sound is generated, or a
 warning light is lighted or lighted on and off. However, the driver may
 fail to hear the warning sound, or overlook the warning light due to
 external disorders, such as a driver's driving state, driver's driving
 ability, a running state, a road surface state or an environment inside
 the vehicle. Or, even if the driver notices the warning, the driver may
 not properly respond due to the above stated situations.
 In such an emergency situation, the vehicle may cause a sudden spin or slip
 by a driver's evading action to thereby lead to a rolling or collision. In
 a conventional protecting device, such as a seat belt device and air bag,
 only when a collision of the vehicle with the obstacle occurs, the
 protecting device starts operating to protect the occupant, and does not
 start operating corresponding to an unstable running state of the vehicle.
 Japanese Patent Publication (KOKAI) No. 10-306392 discloses a system
 wherein in case a collision is foreseen and a possibility of the collision
 is determined to be high, a belt retreating mechanism of a seat belt
 device is automatically operated.
 The seat belt device is provided with a collision foreseeing sensor,
 wherein when the collision is foreseen, a tensile strength of a seat belt
 is made larger to apply a pre-tension thereto. In the device, an
 acceleration in a rolling direction is detected, and in case rolling of
 the vehicle or a damage of a driving ability of the vehicle is going to
 happen, the belt is strongly retracted to remove a slack to thereby fasten
 an occupant to a seat. As described above, a warning by physical notice
 allows the occupant to positively perceive a dangerous situation and at
 the same time protect the occupant.
 However, in the seat belt device disclosed in Japanese Patent Publication
 No. 10-306392, an area and shape of the belt can not be controlled. Also,
 a protection corresponding to physical characteristics of the occupant can
 not be provided.
 Japanese Patent Publication (KOKAI) No. 7-81520 also proposes a seat belt
 device, wherein an obstacle around a vehicle is detected; an obstacle
 degree that the obstacle causes a problem with respect to the vehicle is
 determined; and a seat belt is controlled according to the result thereof.
 More specifically, as the obstacle degree is higher, the tensile strength
 of the belt is made stronger to thereby allow the occupant to bodily sense
 the warning and to protect the occupant beforehand.
 However, the seat belt device disclosed in Japanese Patent Publication No.
 7-81520 does not control the area and shape of the belt, neither. Also,
 the protection corresponding to the physical characteristics of the
 occupant can not be provided.
 As a device where a binding or holding ability of a seat belt device is
 more securely made, there is proposed an inflatable seat belt device in
 Japanese Patent Publication (KOKAI) No. 5-112201. In the seat belt, a
 portion of the seat belt where an occupant shoulder touches is provided
 with a bag-shape portion. The bag-shape portion is expanded through
 injection of gas from a gas generating device at a time of an emergency to
 thereby receive a moving energy of the occupant with the wider area of the
 belt.
 However, in Japanese Patent Publication No. 5-112201, foreseeing of the
 collision and protection corresponding to the physical characteristics of
 the occupant are not considered.
 The above seat belt devices contribute to improvement in safety of the
 occupant. However, a safety system for providing the occupant with more
 appropriate protection is required.
 In view of the above, the present invention has been made and an object of
 the invention is to provide a vehicle safety system for recognizing an
 obstacle and problem around a vehicle or about the vehicle itself and
 estimating a dangerous degree of the obstacle and problem to thereby
 provide an occupant in the vehicle with a warning or more suitable
 protection.
 Further objects and advantages of the invention will be apparent from the
 following description of the invention.
 SUMMARY OF THE INVENTION
 In order to attain the above objects, a vehicle safety system according to
 a first aspect of the present invention includes an obstacle detecting
 device for detecting an obstacle around a vehicle; a vehicle state
 detecting device for detecting states, such as a speed, acceleration,
 rolling, sudden braking, sudden turning and side-slipping of the vehicle;
 a dangerous degree determining device for determining a dangerous level of
 the obstacle with respect to the vehicle and/or a dangerous level of the
 vehicle itself by receiving information from the obstacle detecting device
 and/or the vehicle state detecting device; and a seat belt device disposed
 in the vehicle and having a belt controlling device for changing an area
 and/or shape of a touching portion where the belt touches an occupant
 according to the dangerous level information from the dangerous degree
 determining device.
 Since the shape including the area of the touching portion where the belt
 touches the occupant is controlled according to the determined dangerous
 degree, a more appropriate protection can be provided to the occupant.
 The above vehicle safety system further includes an occupant identifying
 device wherein the physical characteristics of the occupant sitting on a
 seat corresponding to the seat belt device are detected or stored. Thus,
 the area and/or shape of the touching portion where the belt touches the
 occupant can be changed by receiving the information from the occupant
 identifying device, and according to the physical characteristics of the
 occupant sitting on the seat.
 Since the appropriate protection according to the physical characteristics
 of the occupant can be provided, the force and pressure transmitted to the
 occupant and the binding or holding state of the occupant by the belt can
 be more improved.
 More specifically, based on the special information of each occupant, such
 as a physical structure determined from a height and a weight of the
 occupant; strength of a skeletal structure determined from an age, sex and
 the like; and physical characteristics or patient's conditions requiring a
 special care at the time of a seat belt operation, a strong expansion of
 the seat belt is given to an occupant who is tolerable against a strong
 expansion force, and a weak expansion of the seat belt is given to an
 occupant who is not tolerable against the strong expansion force. Thus,
 more appropriate protection can be provided to the occupant without giving
 a burden to a body of the occupant.
 A vehicle safety system according to a second aspect of the present
 invention includes an obstacle detecting device for detecting an obstacle
 around a vehicle; a vehicle state detecting device for detecting states,
 such as a speed, acceleration, rolling, sudden braking, sudden turning and
 side-slipping of the vehicle; a dangerous degree determining device for
 determining a dangerous level of the obstacle with respect to the vehicle
 and/or a dangerous level of the vehicle itself by receiving information
 from the obstacle detecting device and/or the vehicle state detecting
 device; a seat belt device disposed in the vehicle and having a belt
 controlling device for changing a tensile strength of the belt according
 to a dangerous level information from the dangerous degree determining
 device; and an occupant identifying device for detecting or storing
 physical characteristics of the occupant sitting on a seat corresponding
 to the seat belt device. The belt controlling device changes the shape
 including an area of the touching portion of the belt touching the
 occupant by receiving the information from the occupant identifying device
 and according to the physical characteristics of the occupant sitting on
 the seat.
 According to the determined dangerous degree, an appropriate protection can
 be provided to the occupant. Also, according to the physical
 characteristics of the occupant, a strong tensile strength is given to an
 occupant who is tolerable to the strong seat belt tensile strength and a
 weak tensile strength is given to an occupant who is not tolerable against
 the strong seat belt tensile strength. Thus, a perfect protection can be
 provided to the occupant.
 In the vehicle safety system of the present invention, the vehicle state
 detecting device has a sensor for detecting at least one of accelerations
 in front-rear directions, left-right directions and upper-lower directions
 of the vehicle, and angular speeds around axes of the respective
 directions. It is preferable that the dangerous degree determining device
 determines (1) a normal running state, such as start, acceleration,
 turning and braking of the vehicle; (2) an unstable state, such as sudden
 braking, sudden turning and side-slipping of the vehicle; (3) a dangerous
 state which may cause a collision, rolling, spin or the like of the
 vehicle; and 4) an accident state where a collision or rolling of the
 vehicle occurs.
 The tensile strength of the seat belt and/or the shape including the area
 of the portion where the belt touches the occupant can be precisely
 controlled according to the emergency situation, by detecting a direction
 and amount of a load that the vehicle receives and classifying its
 dangerous level.
 Further, it is preferable to have a storing portion for tracking and
 recording a start and completion of the accident or problem determined by
 the dangerous degree determining device, so that the record can be used
 for examining the accident afterward.
 In the vehicle safety system of the invention, the belt controlling device
 of the seat belt device includes the seat belt having a bag-shape portion
 disposed in at least a part of the belt which touches the occupant and
 normally held in a belt-shape; and a belt expansion-contraction device for
 introducing a gas into the bag-shape portion to expand thereof and
 discharging the gas from the bag-shape portion to restore to the
 belt-shape.
 At this time, there is provided a gas pressure controlling device for
 controlling a pressure of the introduced gas.
 Further, an inner portion of the bag-shape portion of the seat belt device
 is partitioned into at least two divisions. The expansion-contraction
 device includes a device for expanding or contracting the respective
 divisions individually or in cooperation together; and a device for
 controlling a gas flow speed and a gas pressure when a gas is introduced
 into or discharged from the respective divisions.
 Further, the gas pressure controlling device includes a gas storing
 portion, wherein an inner pressure is normally held higher than a
 predetermined value, and when the pressure value becomes lower than the
 predetermined value, a gas is introduced from an exterior to increase the
 pressure therein and is stopped when the gas pressure becomes higher than
 the predetermined value.
 In case the bag-shape portion of the belt is expanded at a time of
 emergency, since the tensile strength and pressure of the belt and the
 shape including the area of the portion where the belt touches the
 occupant are changed, the strength and pressure to be applied to the
 occupant and a state for binding or holding the occupant can be set more
 desirably. Further, the seat belt device notifies the occupant of an
 accident or emergency situation through a sense of touch, sense of sight
 and sense of hearing of the occupant. Therefore, a driver can positively
 infer the emergency situation from them to thereby take a measure for
 avoiding the emergency situation. Also, the occupant can be protected from
 a braking movement of the vehicle accompanying the avoiding operation.
 In the present invention, the occupant identifying device includes an
 individual identifying device for identifying occupants sitting on
 respective seats; a data base for storing information about physical
 characteristics of the individuals registered beforehand; and a reading
 device for reading out, from the data base, the information about physical
 characteristics of the occupant identified by the individual identifying
 device.
 The seat belt device provided in each seat in the vehicle can be suitably
 controlled by identifying the occupant sitting on the seat and holding the
 physical characteristics of the occupant.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
 Hereunder, the present invention will be described with reference to the
 accompanying drawings.
 FIG. 1 is a drawing showing a structure of a vehicle safety system of an
 embodiment according to the present invention.
 A vehicle safety system 10 includes an obstacle detecting device 1, a
 vehicle state detecting device 2, an occupant identifying device 3, a
 dangerous degree determining device 4, a dangerous degree storing or
 registering device 5, and a seat belt device 6.
 Data from the obstacle detecting device 1, the vehicle state detecting
 device 2 and the occupant identifying device 3 is inputted into the
 dangerous degree determining device 4 formed of a CPU. The dangerous
 degree determining device 4 determines a dangerous degree based on the
 inputted obstacle information and vehicle state, and controls the seat
 belt device 6 to provide a warning or a protection suitable for physical
 structures and characteristics of an occupant identified by the occupant
 identifying device 3 according to a determined dangerous degree.
 Incidentally, in case the dangerous degree is determined, it may be
 determined based on only information from either the obstacle detecting
 device 1 or the vehicle state detecting device 2.
 The respective devices constituting the vehicle safety system according to
 the invention will be described in detail.
 The obstacle detecting device 1 detects an obstacle in front of a vehicle
 and measures a relative distance between the vehicle and the obstacle. As
 the obstacle detecting device 1, a radar device, a stereo camera device or
 the like may be used. A relative speed for a time is calculated from the
 measured relative distance. In case the relative speed is decreased, the
 vehicle is separated from the obstacle to indicate a condition leaving
 from the obstacle. On the other hand, in case the relative speed is
 increased, the vehicle approaches the obstacle to indicate a condition
 increasing the dangerous degree. The relative distance and the relative
 speed are inputted to the dangerous degree determining device 4 to
 determine possibility of a collision.
 FIG. 2 is a diagram showing relationships between the values detected by
 the obstacle detecting device and collision possibilities, wherein the
 ordinate represents the relative speed and the abscissa represents the
 relative distance.
 In case the relative speed is decreased, the area does not require a
 warning (hereinafter referred to as non-warning requirement area),
 practically regardless of the relative distance. More specifically, in
 case the obstacle and the vehicle are separated from each other, it is not
 required to take an emergency measure, such as sudden braking or sudden
 turning. However, in case the relative speed is positive (+) and the
 relative distance is extremely short, the vehicle is going to collide with
 the obstacle, which becomes a collision watch area. In other words, in
 case the vehicle and the obstacle approach each other very quickly, and
 further come extremely close to each other, there is a high collision
 possibility. Also, an area positioned between the non-warning requirement
 area and the collision watch area becomes a collision warning area since
 the collision can be prevented by providing the warning.
 FIG. 3 is a diagram showing movements of the vehicle detected by the
 vehicle state detecting device.
 The vehicle state detecting device 2 is a sensor for detecting
 accelerations in the front-rear directions, left-right directions or
 upper-lower directions of the vehicle, and angular speeds around axes of
 the respective directions. The rotation along an axis of the front-rear
 directions is called "roll"; the rotation along an axis of the left-right
 directions is called "pitch"; and the rotation along an axis of the
 upper-lower directions is called "yaw" (spin). Time sequence changes of
 the detected respective data are obtained, and compared with the data in
 the normal state thereof. Although the respective values at the normal
 state are smoothly varied, sudden acceleration changes take place at a
 time of emergency. For example, in case a sudden braking is carried out,
 the acceleration in the front direction is suddenly reduced. When the
 vehicle is rolling, the acceleration in a direction opposite to the
 rolling direction is detected by the roll sensor. Also, in case the
 vehicle is spinning at a curve, the angular speed of a yaw sensor becomes
 higher than a predetermined value, and the accelerations in the front-rear
 directions and in the left-right directions are synchronously increased or
 decreased. A rolling of the vehicle is detected by the angular speed and
 time of the roll sensor. The detected values are inputted to the dangerous
 degree determining device 4.
 The occupant identifying device 3 identifies occupants who sit on the
 respective seats in the vehicle to thereby take out information, such as
 physical structures and characteristics of the respective occupants. As
 the occupant identifying device, a fingerprint sensor provided at a buckle
 of a seat belt, ID card and the like can be used. The physical
 characteristics, such as height, weight, age and sex, of the occupants are
 stored in a data base beforehand. Thus, when an occupant or driver gets
 into the vehicle, the occupant is identified by reading a fingerprint of
 the occupant by the fingerprint sensor or inserting his ID card to thereby
 take out information corresponding to the occupant from the data base. The
 taken-out data is inputted to the dangerous degree determining device 4.
 FIG. 4 is a diagram showing a state where the fingerprint sensor is
 attached to the buckle of the seat belt.
 The fingerprint sensor 30 is integrally provided at a buckle 32 of a seat
 belt 31. The buckle 32 is supported by a left hand of the occupant when
 the seat belt 31 is put on, into which a tongue 33 of the seat belt held
 by a right hand is inserted. A side surface of the buckle 32 is provided
 with a groove 34 easily hold the buckle 32. A shallow depressed portion 35
 is formed on an upper surface of the buckle 32, on which a thumb can be
 placed. A detecting surface of the fingerprint sensor is positioned on the
 depressed portion 35. When four fingers except the thumb are inserted into
 the groove 34, the thumb is naturally placed on the depressed portion 35
 to thereby detect the fingerprint of the thumb.
 FIG. 5 is a block diagram of a computer constituting the occupant
 identifying device equipped with the fingerprint sensor as shown in FIG.
 4.
 The computer includes a central processing portion 80, a fingerprint input
 portion 90, an information input portion 100 and a storing portion 110.
 The information input portion 100 has an input device 101, such as a key
 board, with which physical characteristics, such as weights, heights and
 ages, of every occupant permitted by a car owner or his family are
 inputted. The inputted information is stored in a personal information
 data storing portion 111 of the storing portion 110. The fingerprint data
 of the occupants is registered in a fingerprint data storing portion 112
 through a separate fingerprint sensor 102.
 A seat belt device optimizing program 113 is stored in the storing portion
 110. The program controls a tensile strength of the seat belt device and
 an expansion degree of the bag-shape portion according to the occupant's
 physical characteristics stored in the personal information data storing
 portion 111.
 The fingerprint input portion 90 includes the fingerprint sensor 30 and a
 fingerprint checking device 91. The fingerprint read by the fingerprint
 sensor 30 is compared with the fingerprint data stored in the fingerprint
 data storing portion 112 by the fingerprint checking device 91 to
 determine whether the occupant is a registered person or not.
 Therefore, when the fingerprint of the occupant is read by the fingerprint
 sensor 30 of the fingerprint input portion 90, the fingerprint is compared
 with the fingerprint data stored in the fingerprint data storing portion
 112 by the fingerprint checking device 91. When the occupant is
 identified, the physical characteristics of the occupant are taken out
 from the personal information data storing portion 111. Then, the seat
 belt device 6 is suitably operated according to the physical
 characteristics by the seat belt device optimizing program 113. The
 process is controlled according to a controlling program 81 of the central
 processing device 80.
 FIG. 6 is a diagram showing a structure of the seat belt device of the
 embodiment.
 The seat belt device 6 is an inflatable seat belt, in which bag-shape
 portions 61 and 62 are provided to portions where a shoulder belt touches
 a temple portion (side of a head) and a chest portion of the occupant. A
 buckle 63 is provided to a lower end portion of the shoulder belt. The
 buckle is fixed to a seat. On the other hand, an upper end portion of the
 shoulder belt extending upwards beyond the chest portion and the temple
 portion of the occupant is deflected downwards by a deflector (not shown),
 and then fixed to a vehicle body.
 Pipes 64, 65 for supplying expansion gases are connected to the temple side
 bag-shape portion 61 and the chest side bag-shape portion 62,
 respectively, so that the bag-shape portions are expanded separately. The
 other ends of the pipes 64, 65 are connected to a tank 67 of an expansion
 gas, i.e. air, through a gas pressure controlling device 66. Incidentally,
 compressed air is supplied to the tank 67 from a compressor or the like
 loaded on the vehicle.
 FIG. 7(A) is a front view of a folded bag-shape portion of the shoulder
 belt; FIG. 7(B) is a front view of an exploded bag-shape portion; FIG.
 7(C) is a sectional view of the folded bag-shape portion; and FIG. 7(D) is
 a sectional view of the exploded bag shape portion.
 The bag-shape portion 60 is formed by closing outer circumferences of two
 cloth members of a hexagonal shape as shown in FIG. 7(B). These cloth
 members have non-elasticity and an air sealing ability. Two opposing
 corners 60a, 60b of the hexagon of the cloth members are folded between
 two cloths as shown in FIG. 7(C). In a normal folded state, the bag-shape
 portion has a belt shape as shown in FIG. 7(A). When the expansion gas,
 i.e. air, is supplied to the bag-shape portion, the folded corner portions
 60a, 60b open outward to expand the whole bag-shape portion as shown in
 FIG. 7(B).
 The expanded temple side bag-shape portion forms a space between the temple
 portion, i.e. side of a head, of the occupant and the car body to thereby
 reduce problems caused by hitting the temple portion against the car body
 when the vehicle is subjected to a side surface collision, rolling, sudden
 lateral movements or the like. Also, the expanded chest side bag-shape
 portion protects a chest portion of the occupant and at the same time
 reduces problems of the occupant caused by throwing out forward.
 Further, the respective bag-shape portions are provided with two step
 expanding functions, i.e. a first warning expansion step for letting the
 occupant know an emergency situation and a second full expansion step for
 protecting the occupant from the collision. More specifically, in the
 first warning expansion step, the chest side bag-shape portion is expanded
 on the order of a pressure which the occupant can sense to thereby warn
 the occupant about the emergency situation. In the full expansion step,
 i.e. the second step, both chest side bag-shape portion and the temple
 side bag-shape portion are fully expanded to thereby protect the chest
 portion and the temple portion of the occupant. The control of the
 expansions of the bag-shape portions is carried out by the gas pressure
 controlling device 66, such as a variable decompression valve or a
 three-way valve.
 FIG. 8 is a diagram showing changes of an inner pressure in the gas tank,
 wherein the ordinate represents the inner pressure of the gas tank, and
 the abscissa represents time.
 The inner pressure of the tank is maintained at the same pressure as the
 atmospheric pressure at an initial state when the vehicle is shipped from
 a factory or parts are replaced (A1). When the vehicle starts moving, the
 gas pressure controlling device 66 takes air into the gas tank 67 from an
 intake port 68 through a compressor or the like (A2) to thereby keep the
 pressure in the gas tank at an upper limit of increased pressure (A3, i.e.
 3 kgf/cm.sup.2). In case the warning expansion is carried out, a gas is
 supplied to the bag-shape portion until the pressure in the gas tank
 becomes slightly higher than a lower limit, i.e. 2 kgf/cm.sup.2, of
 increased pressure (A4). At this time, the bag-shape portion is expanded
 to the first step and the pressure in the gas tank is held in this value
 (A5). Next, in case the full expansion is carried out, the gas is supplied
 to the bag-shape portions until the pressure in the tank becomes slightly
 lower than a lower limit of reduced pressure (A6, i.e. 1 kgf/cm.sup.2). At
 this time, the bag-shape portions are expanded to the second step where
 the gas supplied at A6 is added to the gas supplied at A4. Thereafter, air
 is again taken in through the intake port (A7) to thereby hold the
 pressure in the gas tank at a predetermined value (A8).
 After the warning expansion, when the warning is suspended or cancelled,
 the gas in the bag-shape portion is discharged from an exhausting port 69
 through the gas pressure controlling device. Also, since the bag-shape
 portion has a function for memorizing the belt-shape (FIGS. 7(A) and
 7(C)), in case the air therein is discharged to reduce the pressure, the
 bag-shape portion returns to the original shape. Incidentally, it is
 sufficient that the pressure at the time of the full expansion in the
 belt-like bag-shape portion is in a range of 0.4 to 0.6 kgf/cm.sup.2.
 The bag-shape portion of the seat belt may be made of an expandable
 material having an airtight ability, such as rubber. In this case, it is
 not necessary to form the bag-shape portion in a folded state. The
 bag-shape portion is expanded from an ordinary state, and returned to the
 ordinary state when air is discharged therefrom.
 Next, a process of the dangerous degree determining device is explained.
 FIG. 9 is a flow chart showing a process of a dangerous degree determining
 device.
 First, at S10, an occupant getting in the vehicle is identified by the
 occupant identifying device to take out a personal information, such as
 the physical characteristics of the occupant. Then, at S11, an obstacle in
 front of the vehicle is detected by the obstacle detecting device to
 calculate a relative speed and a relative distance between the vehicle and
 the obstacle. At S12, a non-warning requirement area or not is determined
 from the relative speed and the relative distance based on a correlation
 drawing as shown in FIG. 2. In case it is determined that the vehicle is
 in the non-warning requirement area, the vehicle is supposed to be in a
 normal running state to thereby advance to S13 to initialize everything
 and then come to an end.
 In case it is determined at S12 that the vehicle is not in the non-warning
 requirement area, the process advances to S14, wherein a collision warning
 area or not is determined. In case the vehicle is determined to be in the
 collision warning area, the process advances to S15 to read values
 outputted from the respective sensors of the vehicle state detecting
 device. In case the values of all the sensors are less than their
 threshold values, the vehicle is supposed to be in a slightly unstable
 running state, and the process goes to S16 wherein the chest side
 bag-shape portion of the seat belt is subjected to the warning expansion
 to thereby call attention of an occupant.
 In case any one of the sensor values is higher than its threshold value at
 S15, the process advances to S17 to compare the roll sensor value and yaw
 sensor value with threshold values thereof. In case any one of the values
 is higher than its threshold, the process goes to S18 where it is
 determined that there is a high possibility of rolling sideways or spin of
 the vehicle, and then advances to S19 where the chest side and temple side
 bag-shape portions of the seat belt are expanded to thereby call the
 occupant's attention, and at the same time, safely fasten the occupant to
 the seat.
 At S17, in case both roll sensor value and yaw sensor value are less than
 their threshold values, the pitch sensor value is supposed to be higher
 than its threshold value. At S20, it is determined also to be in a
 dangerous situation such that there is a possibility of a forward
 revolution or sudden braking. At S21, the chest side bag-shape portion of
 the seat belt is expanded to thereby call the occupant's attention, and at
 the same time, reduces problems caused by throwing out of the occupant
 forward.
 At S14, in case it is determined that the vehicle is not in the collision
 warning area, the process advances to S22, that is the collision watch
 area. At S23, the roll sensor value and the yaw sensor value are compared
 with their threshold values. In case any one of the sensor values is
 higher than its threshold value, the vehicle senses a sudden acceleration
 in the left-right directions to thereby determine at S24 that there is a
 high possibility of a side collision or rolling sideways. At this time, at
 S25, the chest side bag-shape portion and temple side bag-shape portion of
 the seat belt are expanded to reduce problems caused by throwing out of
 the occupant forward or abutting of the occupant temple against a vehicle
 body.
 At S23, in case the roll sensor value or yaw sensor value is less than its
 threshold value, it is determined at S26 that there is a high possibility
 of a head-on collision. At this time, at S27, the chest side bag-shape
 portion of the seat belt is expanded to reduce problems caused by throwing
 of the occupant forwards.
 Incidentally, the expansions of the bag-shape portions are controlled by an
 expansion-contraction controlling device 71 according to the occupants
 physical characteristics read at S10. Further, the seat belt device 6
 includes a belt tensile strength controlling device 70 to thereby control
 the tensile strength of the belt according to the physical characteristics
 of the occupant.
 At the full expansion, generally, as the occupant has a larger physical
 condition or characteristic, the expanding degrees of the chest side
 bag-shape portion and the temple side bag-shape portion of the seat belt
 device become higher, so that the tensile strength of the belt is set at a
 higher value. The warning expansions of both bag-shape portions are set at
 values lower than those of the full expansions.
 The dangerous degree storing device 5 stores the relative speed and
 relative distance calculated at the obstacle detecting device 1, and
 values detected by the roll sensor, yaw sensor and pitch sensor of the
 vehicle state detecting device 2. The information can be used for
 examining the accidents or the like.
 As apparent from the above explanation, the present invention provides a
 vehicle safety system for recognizing an obstacle and problems around the
 vehicle or about vehicle itself and estimating the dangerous degrees to
 thereby provide an occupant with a warning and protection.
 While the invention has been explained with reference to the specific
 embodiments of the invention, the explanation is illustrative and the
 invention is limited only by the appended claims.