Curve approaching mode controller

• US 6,424,904 B1
• Filed: 09/19/2000
• Issued: 07/23/2002
• Est. Priority Date: 09/22/1999
• Status: Expired due to Fees

• Current Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Original Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Inventors: Takahashi, Akira, Matsuura, Munenori
• Primary Examiner(s): Zanelli, Michael J.
• Application Number:
  US09/664,736
• Time in Patent Office: 672 Days
• Field of Search: 701/70, 701/72, 701/45, 701/207, 701/93, 340/438, 340/441
• US Class Current: 701/70
• CPC Class Codes: B60K 31/0083 responsive to centrifugal force acting on vehicle due to the path it is following
• CPC Class Codes: B60W 2520/125 Lateral acceleration
• CPC Class Codes: G01C 21/34 Route searching; Route guidance
• CPC Class Codes: G01C 21/3697 Output of additional, non-guidance related information, e.g. low fuel level G01C21/3679 takes precedence

Abstract

A curve approaching mode controller is capable of continuing vehicle control operations for the longest possible time even if curve information is not available from a navigation system. The navigation system provides curve information about a curve on a road stretching ahead of a vehicle. A control unit estimates a curve approaching mode in which the vehicle will approach the curve on the basis of the curve information and, when necessary, gives a warning and executes a decelerating control operation. If only insufficient curve information is available from the navigation system, a road attribute calculating and storing unit stores the normal node information received immediately before receiving the insufficient node information (curve information) without updating the same, and informs a warning speed calculating and storing unit of a fact that the node information is insufficient. A warning speed calculating and storing unit calculates a warning speed that serves as a reference for warning on the basis of the normal node information received immediately before receiving the insufficient node information, taking a distance traveled by the vehicle after the insufficient node information has been received.

Claims

1. A curve approaching mode controller comprising:

a curve information retrieving unit for retrieving curve information about a curve in a road stretching ahead of a vehicle; and

a control unit for estimating a curve approaching mode in which the vehicle will approach the curve on the basis of the curve information retrieved by the curve information retrieving unit and executing predetermined control operations;

wherein the control unit estimates, when the curve information retrieved by the curve information retrieving unit is insufficient for curve approaching mode estimation, a curve approaching mode in which the vehicle will approach the curve on the basis of curve information provided before the curve information becomes insufficient.

2. The curve approaching mode controller according to claim 1, wherein the control unit completes a curve approaching mode estimating operation in a predetermined time period when the curve information is insufficient.

3. The curve approaching mode controller according to claim 1, wherein the control unit completes a curve approaching mode estimating operation while the vehicle travels a predetermined distance when the curve information is insufficient.

4. The curve approaching mode controller according to claim 1, wherein the control unit includes a storage unit for storing the curve information provided by the curve information retrieving unit, and a warning speed calculating unit for calculating a warning speed as a reference data for the curve approaching mode estimating operation on the basis of the curve information stored in the storage unit;

the storage unit holds the stored curve information without updating the same when the curve information retrieving unit provides insufficient curve information insufficient for a curve approaching mode estimation, and gives notice that the insufficient curve information is provided to the warning speed calculating unit; and

the warning speed calculating unit calculates the warning speed upon the reception of the notice on the basis of the curve information previously stored in the storage unit.

5. The curve approaching mode controller according to claim 4, wherein the control unit further includes a warning command output unit for deciding whether a warning should be given on the basis of a running speed at which the vehicle is running at present and a warning speed calculated by the warning speed calculating unit, and giving a control signal to a warning device according to the result of decision.

6. The curve approaching mode controller according to claim 4, wherein the control unit further includes a deceleration command output unit for deciding whether forced deceleration is necessary on the basis of a running speed at which the vehicle is running at present and a warning speed calculated by the warning speed calculating unit, and giving a control signal to a decelerating device according to the result of decision.

7. The curve approaching mode controller according to claim 4, wherein the control unit further includes:

a warning command output unit for deciding whether a warning should be given on the basis of a running speed at which the vehicle is running at present and a warning speed calculated by the warning speed calculating unit, and giving a control signal according to the result of decision to a warning device and a deceleration command output unit for monitoring operations of the vehicle after the warning command output unit has decided that a warning should be given, and giving a control signal to a decelerating device when the driver does not execute a proper decelerating operation in a predetermined time.

8. The curve approaching mode controller according to claim 5, further comprising a road shape recognizing device for recognizing a shape of the road stretching ahead of the vehicle on the basis of image information about the road;

wherein the control unit decides whether a curve corresponding to the curve information exists actually on the road on the basis of the result of a road shape recognizing operation of the road shape recognizing device, and controls the warning command output unit according to the result of decision.

9. The curve approaching mode controller according to claim 7, further comprising a road shape recognizing device for recognizing a shape of the road stretching ahead of the vehicle on the basis of image information about the road;

wherein the control unit decides whether a curve corresponding to the curve information exists actually on the road on the basis of the result of a road shape recognizing operation of the road shape recognizing device, and controls the warning command output unit according to the result of decision.

10. The curve approaching mode controller according to claim 6, further comprising a road shape recognizing device for recognizing a shape of the road stretching ahead of the vehicle on the basis of image information about the road;

wherein the control unit decides whether a curve corresponding to the curve information exists actually on the road on the basis of the result of a road shape recognizing operation of the road shape recognizing device, and controls the decelerating command output unit according to the result of decision.

11. The curve approaching mode controller according to claim 7, further comprising a road shape recognizing device for recognizing a shape of the road stretching ahead of the vehicle on the basis of image information about the road;

wherein the control unit decides whether a curve corresponding to the curve information exists actually on the road on the basis of the result of a road shape recognizing operation of the road shape recognizing device, and controls the decelerating command output unit according to the result of decision.

12. The curve approaching mode controller according to claim 1, wherein the curve information retrieving unit is a navigation system holding road map data.