Occupant restraint system and occupant restraint method

An occupant restraint system, comprising:

• a seat belt tension application device that adjusts tension applied to a seat belt to restrain an occupant with the seat belt;
• a longitudinal acceleration detector that detects a longitudinal acceleration occurring in a vehicle along a longitudinal direction;
• a lateral acceleration detector that detects a lateral acceleration occurring in the vehicle along a lateral direction;
• and
• a control device that controls the tension applied by the seat belt tension application device based upon a longitudinal acceleration detection value detected by the longitudinal acceleration detector and a lateral acceleration detection value detected by the lateral acceleration detector, wherein:
• an XY two-dimensional map, with a deceleration (negative acceleration) of the vehicle occurring along the longitudinal direction set on a +Y axis, an acceleration of the vehicle manifesting along the longitudinal direction set on a −Y axis, an acceleration of the vehicle to a right set on a +X axis and an acceleration of the vehicle manifesting to a left set on a −X axis, is provided;
• a first operation decision-making threshold line, which forms one of a semi-elliptic shape and a polygonal shape, intersects the +X axis at A, intersects the −X axis at −A and intersects the +Y axis at +B satisfying B<A, is set in a first quadrant and a second quadrant of the map;
• and
• the control device engages the seat belt tension application device to apply the tension to the seat belt if a point on the map determined in conformance to the longitudinal acceleration detection value and the lateral acceleration detection value obtained as the vehicle decelerates is outside a range enclosed by the first operation decision-making threshold line and the X axis.

An occupant restraint system, comprising:

• a seat belt tension application device that adjusts tension applied to a seat belt to restrain an occupant with the seat belt;
• a longitudinal acceleration detector that detects a longitudinal acceleration occurring in a vehicle along a longitudinal direction;
• a lateral acceleration detector that detects a lateral acceleration occurring in the vehicle along a lateral direction;
• and
• a control device that controls the tension applied by the seat belt tension application device based upon a longitudinal acceleration detection value detected by the longitudinal acceleration detector and a lateral acceleration detection value detected by the lateral acceleration detector, wherein:
• an XY two-dimensional map, with a deceleration (negative acceleration) of the vehicle occurring along the longitudinal direction set on a +Y axis, an acceleration of the vehicle occurring along the longitudinal direction set on a −Y axis, an acceleration of the vehicle to a right set on a +X axis and an acceleration of the vehicle to a left set on a −X axis, is provided;
• an operation decision-making threshold line, which forms a substantial semi-elliptic shape achieved by connecting a plurality of quadratic curves at a plurality of inflection points intersects the +X axis at A, intersects the −X axis at −A and intersects the +Y axis at +B satisfying B<A, is set in a first quadrant and a second quadrant of the map;
• and
• the control device engages the seat belt tension application device to apply the tension to the seat belt if a point on the map determined in conformance to the longitudinal acceleration detection value and the lateral acceleration detection value obtained as the vehicle decelerates is outside a range enclosed by the semi-elliptic operation decision-making threshold line and the X axis.

An occupant restraint system, comprising:

• a seat belt tension application device that adjusts tension applied to a seat belt to restrain an occupant with the seat belt;
• a longitudinal acceleration detector that detects a longitudinal acceleration occurring in a vehicle along a longitudinal direction;
• a lateral acceleration detector that detects a lateral acceleration occurring in the vehicle along a lateral direction;
• and
• a control device that controls the tension applied by the seat belt tension application device based upon a longitudinal acceleration detection value detected by the longitudinal acceleration detector and a lateral acceleration detection value detected by the lateral acceleration detector, wherein:
• an XY two-dimensional map, with a deceleration (negative acceleration) of the vehicle occurring along the longitudinal direction set on a +Y axis, an acceleration of the vehicle occurring along the longitudinal direction set on a −Y axis, an acceleration of the vehicle to a right set on a +X axis and an acceleration of the vehicle to a left set on a −X axis, is provided;
• an operation decision-making threshold line, which forms a polygonal shape achieved by connecting a plurality of sides at, at least, one inflection point intersects the +X axis at A, intersects the −X axis at −A and intersects the +Y axis at +B satisfying B<A, is set in a first quadrant and a second quadrant of the map;
• and
• the control device engages the seat belt tension application device to apply the tension to the seat belt if a point on the map determined in conformance to the longitudinal acceleration detection value and the lateral acceleration detection value obtained as the vehicle decelerates is outside a range enclosed by the polygonal operation decision-making threshold line and the X axis.

An occupant restraint system, comprising:

• a seat belt tension application means for adjusting tension applied to a seat belt to restrain an occupant with the seat belt;
• a longitudinal acceleration detection means for detecting a longitudinal acceleration occurring in a vehicle along a longitudinal direction;
• a lateral acceleration detection means for detecting a lateral acceleration occurring in the vehicle along a lateral direction;
• and
• a control means for controlling the tension applied by the seat belt tension application means based upon a longitudinal acceleration detection value detected by the longitudinal acceleration detection means and a lateral acceleration detection value detected by the lateral acceleration detection means, wherein:
• a two-dimensional map, with a deceleration (negative acceleration) occurring in the vehicle along the longitudinal direction set on a +side of one of two axes orthogonally intersecting each other in a two-dimensional coordinate system, an acceleration of the vehicle occurring along the longitudinal direction set on a −side of the one axis, an acceleration of the vehicle to a right set on a +side of the other axis in the two-dimensional coordinate system and an acceleration of the vehicle to a left set on a −side of the other axis, is provided;
• an operation decision-making threshold line connecting an intersecting point +A at which the other axis is intersected on the +side, an intersecting point −A at which the other axis is intersected on the −side and an intersecting point +B satisfying B<A at which the one axis is intersected on the +side is set in a first quadrant and a second quadrant of the map;
• and
• the control means engages the seat belt tension application means to apply the tension to the seat belt if a point on the map determined in conformance to the longitudinal acceleration detection value and the lateral acceleration detection value obtained as the vehicle decelerates is outside a range enclosed by the operation decision-making threshold line and the other axis.

An occupant restraint method achieved by using a two-dimensional map, with a deceleration (negative acceleration) of a vehicle occurring along a longitudinal direction set on a +side of one of two axes orthogonally intersecting each other in a two-dimensional coordinate system, an acceleration of the vehicle occurring along the longitudinal direction set on a −side of the one axis, an acceleration of the vehicle to a right set on a +side of the other axis in the two-dimensional coordinate system and an acceleration of the vehicle to a left set on a −side of the other axis, in which a semi-elliptic or polygonal decision-making threshold line intersecting the other axis on the +side at A, intersecting the other axis on the −side at −A and intersecting the one axis on the +side at +B satisfying B<A is set, comprising:

• detecting an acceleration of the vehicle occurring along the longitudinal direction;
• detecting an acceleration of the vehicle occurring along the lateral direction;
• and
• applying tension to a seat belt so as to restrain an occupant when a point on the map determined in conformance to a longitudinal acceleration detection value and a lateral acceleration detection value obtained as the vehicle decelerates is outside a range enclosed by the operation decision-making threshold line and the other axis.