Track map generator

• US 6,420,997 B1
• Filed: 06/08/2001
• Issued: 07/16/2002
• Est. Priority Date: 06/08/2000
• Status: Expired due to Fees

• Current Assignee: Automotive Systems Laboratory, Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Automotive Systems Laboratory, Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Cong, Shan
• Primary Examiner(s): Sotomayor, John B.
• Application Number:
  US09/877,493
• Publication Number:
  US 20020044081A1
• Time in Patent Office: 403 Days
• Field of Search: 342/70, 342/71, 342/72, 701/48, 701/33, 701/36, 701/93, 701/96, 701/117, 701/200, 701/301, 340/901, 340/436, 180/167, 180/170
• US Class Current: 342/70
• CPC Class Codes: G01S 13/723 by using numerical data
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/9322 using additional data, e.g. driver condition, road state or weather data
• CPC Class Codes: G01S 2013/9329 cooperating with reflectors or transponders

Abstract

A radar system (14, 20, 22) generates a plurality of data points (x, y) representative of the position of a tracked object (48), and a representation of an associated path (50, 60) is formed therefrom. At least one quality measure, and at least one heading measure, of said representation, is calculated corresponding to at least one map coordinate (44). The quality and heading measures are stored in memory as a track map. Data from other tracked objects (58) is used to update the track map (38), resulting a plurality of heading values at associated map coordinates (44) that are representative of a path (42) followed by the tracked objects (48, 58).

Claims

1. A method of generating a track map, comprising:

a. reading a first plurality of first data points, wherein each first data point of said first plurality of first data points is representative of a position of first tracked object;

b. generating a first representation of a path of said first tracked object, from said first plurality of first data points;

c. calculating at least one quality measure of said representation, wherein said at least one quality measure corresponds to at least one map coordinate;

d. calculating at least one heading measure from said representation, wherein said at least one heading measure corresponds to said at least one map coordinate; and

e. storing said at least one quality measure and said at least one heading measures in a memory.

2. A method of generating a track map as recited in claim 1, wherein said first representation of said path is a mathematical representation selected from a linear fit of said first plurality of first data points, a curve fit of said first plurality of first data points, a Kalman smoothing of said first plurality of first data points, and an autoregression of said first plurality of first data points.

3. A method of generating a track map as recited in claim 1, wherein said at least one quality measure is responsive to a measure of fit by said representation of said first plurality of first data points.

4. A method of generating a track map as recited in claim 1, further comprising:

a. reading a first plurality of second data points, wherein each second data point of said first plurality of second data points is representative of a velocity of first tracked object, and said first plurality of second data points correspond in time to said first plurality of first data points; and

b. calculating a first plurality of headings of said first tracked object from said first plurality of second data points, wherein said at least one quality measure is responsive to a heading error, wherein said heading error is responsive to a difference between at least one heading calculated from said first representation and at least one heading of said first plurality of headings.

5. A method of generating a track map as recited in claim 1, further comprising:

a. reading a first plurality of third data points, wherein each third data point of said first plurality of third data points is representative of a heading of first tracked object so that said first plurality of third data points are a first plurality of headings, said first plurality of third data points correspond in time to said first plurality of first data points, wherein said heading error is responsive to a difference between at least one heading calculated from said first representation and at least one heading of said first plurality of headings.

6. A method of generating a track map as recited in claim 1, further comprising modifying at least one stored quality measure responsive to at least one quality measure.

7. A method of generating a track map as recited in claim 1, further comprising modifying at least one stored heading measure responsive to at least one quality measure.