Vehicle distance data processor

• US 5,600,561 A
• Filed: 02/09/1995
• Issued: 02/04/1997
• Est. Priority Date: 02/10/1994
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Okamura, Shigekazu
• Primary Examiner(s): ZANELLI, MICHAEL J
• Application Number:
  US08/385,882
• Time in Patent Office: 726 Days
• Field of Search: 364/460, 364/461, 180/167, 180/168, 180/169, 342/70, 342/71, 342/72, 342/107, 342/109, 342/114, 342/118, 342/145, 340/903, 340/904, 356/3, 356/4.01, 356/4.07
• US Class Current: 701/300
• CPC Class Codes: G01S 17/08 for measuring distance only indirect measurement G01S17/46; active triangulation systems G01S17/48
• CPC Class Codes: G01S 17/66 Tracking systems using electromagnetic waves other than radio waves

Abstract

A vehicle distance data processor precisely correlates or matches points of detection in a time serial manner to thereby accurately determine distances of a subject vehicle to a plurality of other vehicles or obstacles lying ahead as well as relative velocity vector data indicative of a velocity vector of each of the other vehicles or obstacles relative to the subject vehicle. Currently obtained coordinate data is correlated or matched with previously obtained coordinate data by means of a matching element 5A on the basis of coordinate data obtained by a distance data converting element 3A, reflection strength data obtained by a distance data/reflection-strength data input element 2A, and predicted coordinate data obtained by a coordinate data predicting element 4A.

Claims

1. A vehicle distance data processor comprising:

distance measuring means which generates electromagnetic waves in a plurality of directions and receives electromagnetic waves reflected from objects to provide reflection strength data regarding the strengths of the reflected electromagnetic waves and distances to the objects;

distance data converting means for converting distance data obtained by said distance measuring means into coordinate data of the positions of the points of detection;

predicting means for predicting coordinate data of each currently obtained detection point based on the coordinate data of each previously obtained detection point and relative velocity vector data related to each detection point;

matching means for matching each previously obtained detection point and each currently obtained detection point in a time serial manner, based on the predicted coordinate data obtained by said predicting means, the strength of the reflected electromagnetic waves of each previously obtained detection point, and the coordinate data of each currently obtained detection point and the strength of reflected electromagnetic waves thereat;

relative velocity computing means which computes the relative velocity vector data based on the detection points which have been matched with their respective points by said matching means, with the computed relative velocity vector data being used in said predicting means; and

candidate vehicle data computing means for obtaining candidate vehicle data by computation of a currently obtained detection point based on the coordinate data of each currently obtained detection point and relative velocity vector data, to obtain coordinate data and velocity vector data of said currently obtained detection point.

2. A vehicle distance data processor according to claim 1 further comprising reflection strength order determining means for ordering the detection points based on the strengths of reflected electromagnetic waves obtained by said distance measuring means, wherein said matching means matches each previously obtained detection point and each currently obtained detection point in a time serial manner, based on the predicted coordinate data predicted from each previously obtained detection point, the strength of reflected electromagnetic waves at each previously obtained detection point, and the order of the detection points arranged according to the reflection strengths thereof, the coordinate data of each currently obtained detection point, the strength of reflected electromagnetic waves at each currently obtained detection point, and the order of the detection points according to the reflection strengths thereof.

3. A vehicle distance data processor according to claim 1 further comprising object determining means for determining the type of an object at each detection point based on distance data of a distance to each of the detection points and reflection strengths obtained by said distance measuring means, wherein said matching means matches each currently obtained detection point and each previously obtained detection point in a time serial manner, based on the predicted coordinate data predicted from each previously obtained detection point, results of previous determinations obtained by said object determining means, coordinate data of each currently obtained detection point, and current determinations obtained by said object determining means.

4. A vehicle distance data processor according to claim 3 further comprising strength predicting means for predicting the strength of reflected electromagnetic waves at each currently obtained detection point, based on the strength of reflected electromagnetic waves at each currently obtained detection point and relative velocity vector data related to each detection point, wherein said matching means matches each previously obtained detection point and each currently obtained detection point in a time serial manner, based on the predicted coordinate data predicted from each previously obtained detection point, the predicted strength of reflected electromagnetic waves obtained by said reflection strength predicting means, the coordinate data of each currently obtained detection point, and the reflection strengths thereat.

5. A vehicle distance data processor according to claim 1 further comprising grouping means which arranges coordinate data into groups of closely located detection points to obtain representative coordinate data and a representative strength of reflected magnetic waves of the group, wherein the representative coordinate data and the representative strength of reflection are used as the coordinate data and the reflection strength, respectively, of each detection point.

6. A vehicle distance data processor as claimed in claim 1, wherein the matching means determines matching between the currently obtained detection points and the previously obtained detection points by comparing the coordinate data of the currently obtained detection points to the predicted coordinate data obtained by said predicting means, and comparing the strength of the reflected electromagnetic waves of each previously obtained detection point to the strengths of reflected electromagnetic waves of the currently obtained detection points.