JP4051153B2 - Seat belt tensioning device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a seat belt tensioning device that tensions a seat belt that restrains and protects an occupant of a vehicle to a seat under a certain condition to improve occupant protection.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in order to protect an occupant from a vehicle accident, a seat belt tensioning device has been proposed in which a seat belt is tightened (tension) at the moment of a vehicle collision so as to restrain the occupant to the seat (for example, Japanese Patent Laid-Open No. Sho-sho) 49-61822, Japanese Utility Model Laid-Open No. 6-35061).
[0003]
[Problems to be solved by the invention]
However, if the occupant is not wearing the seat belt correctly, the automatic tension of the seat belt may cause a malfunction. For example, if a seat belt is hung on the occupant's neck, the neck may be damaged. Further, when the possibility of a collision is increased by a collision prediction function or the like, it is conceivable that the seat belt is wound up or tensioned in advance. When such a safety mechanism is introduced, if the occupant puts his / her hand in the inner pocket of the outerwear, it is conceivable that his / her hand is caught between the seat belts and the avoidance of danger by operating the steering wheel is prevented.
[0004]
Accordingly, an object of the present invention is to provide a seat belt tensioning device that tensions a seat belt after confirming safety when the tension of the seat belt is automatically started.
[0005]
It is another object of the present invention to provide a seat belt retractor that winds up a seat belt after confirming safety when the seat belt retracts automatically.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a seat belt tensioning device that enhances occupant restraint by tensioning or winding a seat belt that restrains an occupant seated in a vehicle seat under certain conditions. Whether the seatbelt is tensioned or retracted by looking at the seatbelt wearing state even when the above condition is satisfied, and the wearing state monitoring means (61) for monitoring the seatbelt wearing state Determination means (50a) for determining whether or not.
[0007]
By adopting such a configuration, it is possible to avoid automatic tension or winding of the seat belt when the seat belt is not correctly worn or when it is not preferable to restrain the occupant. .
[0008]
Preferably, the use state of the seat belt of the occupant determines whether it is appropriate to obtain image data in a seated state by the imaging device and to perform tension or winding of the seat belt by analysis of the image data. By performing image data analysis, it is possible to discriminate and learn various states.
[0009]
Preferably, the analysis of the image data is performed by a pattern recognition technique such as a pattern matching method.
[0010]
Preferably, the imaging device is provided on the vehicle interior roof in front of the occupant, but is not limited thereto.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0012]
FIG. 1 schematically shows the inside of the passenger compartment. In the figure, reference numeral 12 denotes a seat attached to the floor in the passenger compartment, and 13 denotes a seat belt retractor attached to the side wall of the vehicle, and an electric retractor mechanism (not shown) for retracting the seat belt 15 by a motor. Built in. Reference numeral 64 denotes a retractor mechanism drive circuit that operates the electric retractor mechanism in response to a command from the control unit 50b, and reference numeral 14 denotes a through member that is attached to the side wall of the vehicle and folds back the seat belt. Reference numeral 16 denotes a tongue plate for inserting the seat belt, and reference numeral 18 denotes a buckle that can be connected to the tongue plate. A buckle switch S for detecting the connection between the tongue plate and the buckle is built in the buckle 18. 19 is an anchor plate for holding one end of the seat belt 15, 20 is an explosive or gas expansion tension device, and 65 is a tension device drive circuit that operates the tension device 20 in response to a command from the control unit 50b. 13 to 19 correspond to seat belt devices.
[0013]
Reference numeral 61 denotes a small image pickup device that is provided with a CCD element or the like provided in a roof portion or the like in front of the passenger compartment in order to photograph a passenger. 50a is a determination unit that analyzes captured image data to determine the seat belt wearing state, 62 is an acceleration sensor that detects a change in the speed of the vehicle, 63 is a front by a detection mechanism such as laser radar, ultrasonic radar, or electromagnetic wave radar. The inter-vehicle distance sensor 50b that measures the inter-vehicle distance from the vehicle determines whether or not the seat belt is worn by the buckle switch S. Further, the collision and the approach of the vehicle ahead are determined based on the outputs of the acceleration sensor 62 and the inter-vehicle distance sensor 63, and when the seat belt is normally worn, the drive circuit 64 or 65 is operated to operate the seat belt. It is a control unit that performs a steep or moderate tension. Sudden tension is performed by the tension mechanism 20. The gentle tension is performed by an electric retractor in the winding device 13.
[0014]
FIG. 2 is a block diagram illustrating an outline of the microcomputer system 50 constituting the determination unit 50a and the control unit 50b. The microcomputer system 50 includes a ROM 51 that stores control programs, control data, pattern matching data, and the like, a RAM 52 that stores programs, data, various flag data, and image data, a CPU 53 that performs arithmetic processing, an input / output interface 54, an image input The interface 55, the data bus 56, and the like are included.
[0015]
The input / output interface 54 converts the acceleration signal supplied from the acceleration sensor 62 and the inter-vehicle distance signal supplied from the inter-vehicle distance sensor, writes the data into a predetermined area of the RAM 52 by the DMA operation, and outputs the closing signal from the buckle switch S. In response, a seat belt wearing flag is set, and a signal output from the CPU is supplied to the drive circuits 64 and 65 as a seat belt tension signal and a seat belt retracting signal, respectively. The image input interface 55 writes the frame data periodically sent from the imaging device 61 into the image data area of the RAM 52 by the DMA operation.
[0016]
The microcomputer system 50 can be constituted by a so-called microcontroller having a one-chip configuration.
[0017]
FIG. 3 is a flowchart for explaining the operation of the determination unit 50a. The image input interface 55 writes the image data corresponding to one frame transferred from the imaging device 61 to the image data processing area of the RAM 50, and sets the image capture flag in the flag area (flag register) of the RAM 52 to ON. The CPU 53 executes a main program (not shown) to periodically monitor the flag register, and when it knows that image data has been written, it executes a belt attachment state determination routine. In the embodiment, the belt wearing state is determined by pattern recognition. However, other methods may be used.
[0018]
First, the CPU 53 performs a contour extraction process on the sample image, and extracts contours (shapes) of the passenger's head, neck, shoulders, chest, arms, waist, crotch, and the like. Also, the contour (shape) of the seat belt is extracted (S22). Next, the contour image of the passenger and the seat belt is normalized and compared with a plurality of seat belt wearing reference patterns previously stored in the ROM 51. Then, the reference pattern that most closely approximates the shape pattern of the sample is determined (S24). The plurality of reference patterns include a plurality of normal wearing state patterns, a plurality of abnormal wearing state patterns, for example, where the belt is in the vicinity of the passenger's neck, and the arm is restrained by the belt (inside the belt Are available). The CPU 53 determines whether or not the reference pattern that approximates the shape pattern of the sample is a safe wearing state of the seat belt (S26).
[0019]
When the color imaging device 61 is used, it is possible to add the color of the seat belt to the pattern determination condition. In addition, a mark (mark, pattern, color coding) for easily discriminating the presence and fastening state of the seat belt is attached to the belt, and this mark is stored in advance in the ROM database to perform partial pattern matching. You may be able to do it. By tracking this mark, it becomes possible to know the extended state of the belt.
[0020]
Pattern recognition is not limited to the above-described pattern matching method for the contour of an image. For example, feature parameters indicating features corresponding to seat belt wearing conditions such as lateral, diagonal (lower right / lower, lower left / lower) direction of the seat belt pattern, distortion of seat belt extension, etc. are extracted. Thus, the appropriateness of the belt wearing state may be determined.
[0021]
If it is determined to be safe (S26; Yes), a belt tension permission flag for allowing belt tension is set to ON in the flag register. If it is determined that it is not safe (S26; No), the belt tension permission flag in the flag register is set to OFF (S30). Since the CPU 53 has finished the image processing, it sets the image capture flag to OFF to enable detection of writing of the next image data, and returns to the main program.
[0022]
FIG. 4 is a flowchart for explaining a seat belt tensioning process. When the acceleration signal supplied from the acceleration sensor 62 exceeds the noise removal threshold level, the input / output interface 54 writes the signal value into the RAM 52 and sets the acceleration reading flag of the flag register to ON. In addition, an interrupt signal is supplied to the CPU 53.
[0023]
The CPU 53 performs an interrupt process. The CPU 53 jumps to the address of the flag register, determines that the acceleration reading flag of the flag register is on, and reads the acceleration signal value (S42). If the signal value requires data processing, the signal processing is performed to calculate the estimated acceleration (or impact force) (S44).
[0024]
It is determined whether or not the acceleration (or impact force) exceeds a reference value for determining a collision (S46). When the collision is not determined (S46; non-collision), the acceleration reading flag is set to OFF and the process returns to the process before the interruption.
[0025]
When it is determined that there is a collision (S46; collision), the flag register is referenced to determine whether or not the belt tension permission flag is on (permitted) (S48). If the belt tension permission flag is off (S48; not permitted), the belt is not tensioned, the acceleration reading flag is set to off, and the process returns to the process before interruption.
[0026]
When the belt tension permission flag is ON (S48; permission), the CPU 53 supplies a seat belt tension signal to the drive circuit (seat belt tension circuit) 65 via the input / output interface 54, and ignites the explosive of the belt tension device 20. Equally, the passenger is quickly restrained to the seat (S50). Thereafter, the acceleration reading flag is set to OFF, and the process returns to the process before the interruption. Therefore, belt tension is performed when the seat belt is properly worn.
[0027]
FIG. 5 is a flowchart for explaining a seat belt winding process. The input / output interface 54 writes the value of the inter-vehicle distance signal supplied from the inter-vehicle distance sensor 63 into the RAM 52 and sets the inter-vehicle distance reading flag in the flag register to ON. In addition, an interrupt signal is supplied to the CPU 53.
[0028]
The CPU 53 jumps to the address of the flag register in response to the interrupt signal and performs interrupt processing. It is determined that the inter-vehicle distance reading flag in the flag register is turned on, and the inter-vehicle distance signal value is read from a predetermined area of the RAM 52 (S52). Note that when both the inter-vehicle distance reading flag and the acceleration reading flag are on, the belt tension processing is prioritized. If data processing is required for the signal value, signal processing is performed to calculate the estimated inter-vehicle distance (S54).
[0029]
It is determined whether or not the inter-vehicle distance is equal to or less than a predetermined safe distance from the preceding vehicle (S56). When it is determined that the distance is a safe distance (S56; non-approaching), the inter-vehicle distance reading flag is set to OFF, and the process returns to the process before interruption.
[0030]
When it is determined that the distance is less than the safe distance (S56; approach), it is determined whether or not the belt tension permission flag is on (permitted) with reference to the flag register (S58). When the belt tension permission flag is off (S58; not permitted), the inter-vehicle distance reading flag is set to off without performing belt winding, and the process returns to the process before interruption.
[0031]
When the belt tension permission flag is ON (S58; permission), the CPU 53 supplies the seat belt winding signal to the drive circuit (seat belt winding circuit) 64 via the input / output interface 54, and the belt winding device 13 Driving power is supplied to the motor of the belt winding mechanism of the belt, the belt is wound up, and the passenger is restrained on the seat (S50). Thereafter, the inter-vehicle distance reading flag is set to OFF, and the process returns to the process before interruption. Therefore, the seed belt is wound when the seat belt is properly worn.
[0032]
【The invention's effect】
As described above, in the seat belt tensioning device of the present invention, the seat belt is tensioned or wound by determining the wearing state of the passenger's seat belt, which is preferable in terms of passenger safety.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating an overall configuration of the present invention.
FIG. 2 is a block diagram illustrating a configuration example of a microcomputer system that constitutes a determination unit 50a and a control unit 50b.
FIG. 3 is a flowchart for explaining a control algorithm for determining a belt mounting state;
FIG. 4 is a flowchart for explaining an algorithm for belt tension processing;
FIG. 5 is a flowchart illustrating an algorithm of a belt winding process.
[Explanation of symbols]
15 Seat belt 13 Seat belt retractor 20 Tension device (cylinder)
50a determination unit 50b control unit 62 acceleration sensor 63 inter-vehicle distance sensor 64 take-up motor drive circuit 65 tension device drive circuit

Claims (3)

A seat belt tensioning device that tensions or winds up a seat belt that restrains an occupant seated in a vehicle seat under a certain condition and increases the restraint of the occupant,
Wearing state monitoring means for photographing a passenger's seat belt wearing state;
Even when the predetermined condition is satisfied, a pattern of the occupant and the seat belt is further extracted from the photographed image of the occupant's seat belt wearing state, and based on the state of both patterns, the seat belt Judgment means for deciding whether to take tension or winding,
Seat belt tensioning device. The seatbelt device according to claim 1, wherein the wearing state monitoring unit is an imaging device that images a passenger wearing the seatbelt . The discriminating means compares the pattern obtained by performing contour extraction processing and normalization processing on the image from the imaging device with reference patterns of various seat belt wearing states that are held in advance, and approximates the pattern. The seat belt device according to claim 2, wherein the seat belt device is discriminated .

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