Warning device for distance between cars
First Claim
1. An automotive car-to-car distance alarm device adapted to measure a distance between a user'"'"'s own automobile and an object existing ahead of the own automobile, judge the presence or absence of danger based on distance data thus obtained, and issue an alarm on the case where it is judged to be dangerous, characterized by comprising:
- distance measuring means for emitting a light beam in a prescribed plurality of directions and measuring a distance to an object in the plurality of directions;
first discriminating means for comparing a change of the distance measured in the first and the second measurement in the same direction by said distance measuring means with a distance of travel of the own automobile and discriminating whether an object existing in that direction is a moving object or a fixed object;
second discriminating means for, when said first discriminating means has judged the presence of not less than a prescribed number of fixed objects ahead of the own automobile, regressing distance data thereof to find the standard deviation and comparing the obtained standard deviation with a prescribed value thereby discriminating whether or not the fixed objects are exclusively nonobstacles incapable of obstructing the travel of the own automobile;
danger deciding means for deciding the presence or absence of danger by a prescribed formula of decision, depending on the kind of object discriminated by said first discriminating means or said second discriminating means; and
alarm issuing means for issuing a prescribed alarm when said danger deciding means has judged the presence of danger.
1 Assignment
0 Petitions
Accused Products
Abstract
A warning device for a distance between cars, for measuring a distance between a car and an object in front of the car, judging the possibility of danger on the basis of distance data thus obtained, and generating an alarm in the case where it is judged to be dangerous. The warning device provides a first alarm (a rear-end collision alarm) generated in a condition of alert which necessitates deceleration or braking, and a second alarm (an alarm for a distance between cars) generated in a condition of alert which does not necessitate deceleration nor braking, the first and second alarms, respectively, being judged by separate formulae for determining. Accordingly, it is possible to positively generate an alarm when deceleration or braking is necessitated. Further, the warning device discriminates a kind of an object being measured (a moving body, obstruction, guardrail or the like) to judge danger according to the kind of the discriminated object. Accordingly, it is possible to improve reliability of an alarm and, in particular, to reduce incorrect alarms such as by a guardrail.
23 Citations
11 Claims
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1. An automotive car-to-car distance alarm device adapted to measure a distance between a user'"'"'s own automobile and an object existing ahead of the own automobile, judge the presence or absence of danger based on distance data thus obtained, and issue an alarm on the case where it is judged to be dangerous, characterized by comprising:
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distance measuring means for emitting a light beam in a prescribed plurality of directions and measuring a distance to an object in the plurality of directions; first discriminating means for comparing a change of the distance measured in the first and the second measurement in the same direction by said distance measuring means with a distance of travel of the own automobile and discriminating whether an object existing in that direction is a moving object or a fixed object; second discriminating means for, when said first discriminating means has judged the presence of not less than a prescribed number of fixed objects ahead of the own automobile, regressing distance data thereof to find the standard deviation and comparing the obtained standard deviation with a prescribed value thereby discriminating whether or not the fixed objects are exclusively nonobstacles incapable of obstructing the travel of the own automobile; danger deciding means for deciding the presence or absence of danger by a prescribed formula of decision, depending on the kind of object discriminated by said first discriminating means or said second discriminating means; and alarm issuing means for issuing a prescribed alarm when said danger deciding means has judged the presence of danger. - View Dependent Claims (2, 3, 4)
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5. An automotive car-to-car distance alarm device adapted to measure a distance between a user'"'"'s own automobile and an object existing ahead of the own automobile, judge the presence or absence of danger based on distance data thus obtained, and issue an alarm on the case where it is judged to be dangerous, characterized by comprising:
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distance measuring means for emitting a light beam in a prescribed plurality of directions and measuring a distance to an object in the plurality of directions; first discriminating means for comparing a change of the distance measured in the first and the second measurement in the same direction by said distance measuring means with a distance of travel of the own, automobile and discriminating whether an object existing in that direction is a moving object or a fixed object; second discriminating means for, when said first discriminating means has judged the presence of not less than a prescribed number of fixed objects ahead of the own automobile, regressing distance data thereof to find the standard deviation and comparing the obtained standard deviation with a prescribed value thereby discriminating whether or not the fixed objects are exclusively nonobstacles incapable of obstructing the travel of the own automobile; danger deciding means provided with a first alarm to be issued when it is in such a state as urges alert and necessitates deceleration or application of brakes and a second alarm to be issued when it is in such a state as deserves alert and yet falls short of necessitating deceleration or application of brakes and adapted to selectively judge the question whether the first alarm is issued, the second alarm is issued, or neither of the alarms is issued in accordance with a first formula of decision formed of one or more formulas of decision taking into account a safety car-to-car distance and a second formula of decision taking into account a difference of speed between the own car and the object, depending on the kind of object discriminated by said first discriminating means or said second discriminating means; and alarm issuing means for issuing an alarm in accordance with the result of the decision by said danger deciding means. - View Dependent Claims (6, 7, 8, 9, 10, 11)
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Specification