ROAD CURVATURE ESTIMATION SYSTEM

• US 20080183419A1
• Filed: 04/01/2008
• Published: 07/31/2008
• Est. Priority Date: 07/15/2002
• Status: Active Grant

• Current Assignee: TK Holdings Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Automotive Systems Laboratory, Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: CONG, Shan, HONG, Lang, SHEN, Shi
• Granted Patent: US 7,626,533 B2
• Time in Patent Office: Days
• US Class Current: 702/155
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: B60K 31/0066 responsive to vehicle path curvature
• CPC Class Codes: B60K 31/0083 responsive to centrifugal force acting on vehicle due to the path it is following
• CPC Class Codes: B60T 2210/24 Curve radius
• CPC Class Codes: B60T 2260/08 Coordination of integrated systems
• CPC Class Codes: B60W 2050/0052 Filtering, filters
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2552/20 Road profile, i.e. the change in elevation or curvature of a plurality of continuous road segments
• CPC Class Codes: B60W 2552/30 Road curve radius
• CPC Class Codes: B60W 2554/4041 Position
• CPC Class Codes: B60W 2554/4042 Longitudinal speed
• CPC Class Codes: B60W 2554/4043 Lateral speed
• CPC Class Codes: B60W 2554/803 Relative lateral speed
• CPC Class Codes: B60W 2554/804 Relative longitudinal speed
• CPC Class Codes: G01C 21/26 specially adapted for navigation in a road network
• CPC Class Codes: G01S 13/58 Velocity or trajectory determination systems; Sense-of-movement determination systems
• CPC Class Codes: G01S 13/723 by using numerical data
• CPC Class Codes: G01S 13/86 Combinations of radar systems with non-radar systems, e.g. sonar, direction finder
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G01S 2013/9325 : for inter-vehicle distance regulation, e.g. navigating in platoons
• CPC Class Codes: G01S 2013/93271 : in the front of the vehicles
• CPC Class Codes: G01S 7/411 : Identification of targets based on measurements of radar reflectivity G01S7/415 takes precedence

Abstract

A processor operatively coupled to a speed sensor adapted to generate a measure of a longitudinal speed of a vehicle on a roadway, and to a source of a measure of yaw rate of the vehicle, provides for selecting a most likely roadway model of a plurality of different roadway models and for outputting a corresponding associated at least one curvature parameter as an estimate of curvature of the roadway, wherein the processor incorporates a plurality of curvature estimators associated with the corresponding plurality of different roadway models.

Claims

1. A road curvature estimation system, comprising:

a. a speed sensor adapted to measure a longitudinal speed of a vehicle on a roadway and to generate a measure of longitudinal speed responsive thereto;

b. a source of a measure of yaw rate of said vehicle; and

c. a processor operatively coupled to said speed sensor and to said source of said measure of yaw rate, wherein said processor comprises a plurality of curvature estimators associated with a corresponding plurality of different roadway models, each said curvature estimator is adapted to estimate at least one associated curvature parameter of a corresponding said different roadway model, said processor provides for selecting a most likely of said different roadway models as a most likely roadway model, and said processor provides for outputting said at least one curvature parameter of said most likely roadway model as an estimate of curvature of said roadway.

2. A road curvature estimation system as recited in claim 1, wherein said processor comprises an interacting multiple model algorithm incorporating a mode jump process characterized by a Markov chain.

3. A road curvature estimation system as recited in claim 2, wherein said interacting multiple model algorithm comprises:

a. a mode-conditioned filter initialization process;

b. a mode-conditioned state propagation process;

c. a combination of mode-conditioned state and covariance propagations;

d. a mode-conditioned update process;

e. a probability evaluation and update process; and

f. process to output state and covariance estimates.

4. A road curvature estimation system as recited in claim 1, wherein said plurality of different roadway models comprise at least two roadway models selected form a straight road model, a quadratic road model, and a clothoid road model.