Patent US5311173 - Navigation system and method using map data

United States Patent m

Komura et al.

Hi]

[45]

US005311173A

Patent Number:
Date of Patent:

5,311,173 May 10, 1994

[54] NAVIGATION SYSTEM AND METHOD USING MAP DATA

[75] Inventors: Fuminobu Komura, Yokohama;

Yoshikazu Hirayama, Katsuta;
Koichi Homma, Yokohama; Makoto
Kato, Kawasaki; Takanori Shibata,
Hitachi; Yoji Matsuoka, Mito; Akira
Kagami, Kawasaki; Michitaka
Kosaka, Sagamihara, all of Japan

[73] Assignee: Hitachi, Ltd., Tokyo, Japan

[21] Appl. No.: 758,302

[22] Filed: Aug. 28, 1991

Related U.S. Application Data

[63] Continuation of Ser. No. 407,359, Sep. 14, 1989.

[30] Foreign Application Priority Data

Sep. 16, 1988 [JP] Japan 63-229965

[51] Int. Cl.s G08G 1/123

[52] U.S. Q 340/995; 73/178 R;

340/988; 364/449

[58] Field of Search 340/995, 990, 988;

73/178 R; 364/449, 444

[56] References Cited

U.S. PATENT DOCUMENTS

3,947,807 3/1976 Tyler et al 340/989

4,758,959 7/1988 Thoone et al 340/990

4,774,672 9/1988 Tsunoda et al 340/995

4,786,908 11/1988 Runnalls 364/449

4,812,845 3/1989 Yamada et al 340/995

4,887,081 12/1989 Iihoshi et al 340/990

4,964,052 10/1990 Ohe 364/449

4,970,652 11/1990 Nagashima 340/995

5,016,007 5/1991 Iihoshi et al 340/995

5,170,165 12/1992 Iihoshi et al 340/995

FOREIGN PATENT DOCUMENTS

166547 1/1986 European Pat. Off. .

270911 6/1988 European Pat. Off. .

2341162 2/1975 Fed. Rep. of Germany .

3439000 4/1986 Fed. Rep. of Germany .

61- 243318 10/1986 Japan .

62- 166210 5/1987 Japan .

63- 066414 3/1988 Japan .
1-140015 6/1989 Japan .
1-162110 6/1989 Japan .

OTHER PUBLICATIONS

"Nikkei Electronics", Nov. 16, 1987, pp. 119-130.
"Nikkei Electronics", Sep. 21, 1987, pp. 88-89.
SAE Technical Paper Series, Feb. 1987, "The Utility of
Low Cost Vehicle Navigation Systems for Fleet Manu-
agement Applications", S. K. Honey et al, pp. 67-71.

Primary Examiner—Brent A. Swarthout

Attorney, Agent, or Firm—Fay, Sharpe, Beall, Fagan,

Minnich & McKee

In a navigation system which has sensors for detecting a running distance, an azimuth, etc. of a vehicle, and a memory for storing map data; a probability density of a position of the vehicle is calculated on the basis of the sensor outputs and the map data for each of quantization units with which a probability computation determined by detection accuracies of the sensors and quantization of the map data can be executed. In addition, a final stage calculation of DP matching between trajectory data obtained from the on-board sensor data from a start point of the vehicle until a current time and a candidate route estimated from the road map data is iteratively executed, whereby a plurality of estimative vehicular positions and uncertainties (costs) corresponding to the respective estimative positions are iteratively evaluated, and a correct vehicular position is estimated by selecting at least one estimative vehicular position of low uncertainty (cost).

35 Claims, 11 Drawing Sheets

CALCULATOR