Drive assist system for a vehicle and the method thereof

• US 5,808,561 A
• Filed: 03/17/1997
• Issued: 09/15/1998
• Est. Priority Date: 04/10/1996
• Status: Expired due to Fees

• Current Assignee: Fuji Jukogyo KK (Subaru Corp.)
• Original Assignee: Fuji Jukogyo KK (Subaru Corp.)
• Inventors: Arai, Kazumasa, Ikeda, Atsushi, Kinoshita, Masahiro
• Primary Examiner(s): Swarthout, Brent A.
• Assistant Examiner(s): TRIEU, VAN THANH
• Application Number:
  US08/819,386
• Time in Patent Office: 547 Days
• Field of Search: 340/435, 340/436, 340/438, 340/439, 340/903, 340/904, 340/905, 180/167, 180/168, 180/169, 180/170, 364/461, 348/148, 348/149, 701/301
• US Class Current: 340/903
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• CPC Class Codes: G01P 3/68 using optical means, i.e. using infrared, visible, or ultraviolet light G01P3/80 takes precedence ; by reflection of waves G01S17/58
• CPC Class Codes: G01S 11/12 using electromagnetic waves other than radio waves

Abstract

In a drive assist system of a vehicle having a function of detecting an inter-vehicle distance between vehicles and a warning is given to a driver for preventing a collision, disclosed are an apparatus for detecting a deceleration of a preceding vehicle based on a vehicle speed of the preceding vehicle, an apparatus for establishing a safe inter-vehicle distance between the vehicle and the preceding vehicle based on the deceleration of the preceding vehicle, and an apparatus for comparing the inter-vehicle distance with the safe inter-vehicle distance and for outputting a warning signal when the inter-vehicle distance is smaller than the safe inter-vehicle distance. Thus, when the deceleration of the preceding vehicle is small, the warning is not issued until the inter-vehicle distance becomes small, whereby the driver'"'"'s intention can be reflected on the drive assist system.

Claims

1. A drive assist system for a vehicle having inter-vehicle distance calculating means for detecting a preceding vehicle running ahead of the vehicle and for calculating an inter-vehicle distance between the vehicle and the preceding vehicle, vehicle speed calculating means for calculating a vehicle speed of the vehicle, preceding vehicle speed calculating means for calculating a vehicle speed of the preceding vehicle based on the inter-vehicle, distance and the vehicle speed of the vehicle and collision preventing means for preventing a collision of the vehicle with the preceding vehicle, said drive assist system comprising:

preceding vehicle deceleration calculating means for calculating a deceleration of the preceding vehicle based on the vehicle speed of the preceding vehicle;

leeway time calculating means responsive to said deceleration of the preceding vehicle for calculating a leeway time;

safe inter-vehicle distance establishing means responsive to said leeway time and the vehicle speed for establishing a safe inter-vehicle distance between the vehicle and the preceding vehicle at least based on a multiplication of said leeway time and the vehicle speed of the vehicle;

inter-vehicle distance comparing means for comparing the inter-vehicle distance with said safe inter-vehicle distance and for outputting a signal when the inter-vehicle distance is smaller than said safe inter-vehicle distance; and

outputting means responsive to said signal for outputting an operation signal so as to operate the collision preventing means.

2. A drive assist system for a vehicle having inter-vehicle distance calculating means for detecting a preceding vehicle running ahead of the vehicle and for calculating an inter-vehicle distance between the vehicle and the preceding vehicle, vehicle speed calculating means for calculating a vehicle speed of the vehicle, preceding vehicle speed calculating means for calculating a vehicle speed of the preceding vehicle based on the inter-vehicle distance and the vehicle speed of the vehicle, and collision preventing means for preventing a collision of the vehicle with the preceding vehicle, said drive assist system comprising:

preceding vehicle deceleration calculating means for calculating a deceleration of the preceding vehicle based on the vehicle speed of the preceding vehicle;

preceding vehicle deceleration judging means for making a judgment of whether or not said deceleration of the preceding vehicle is larger than a specified reference value;

leeway time calculating means responsive to said judgment for altering leeway time to increase when said deceleration is larger than said specified reference value;

safe inter-vehicle distance establishing means for establishing a safe inter-vehicle distance between the vehicle and the preceding vehicle at least based on a multiplication of said leeway time and the vehicle speed of the vehicle;

inter-vehicle distance comparing means for comparing the inter-vehicle distance with said safe inter-vehicle distance and for outputting a signal when the inter-vehicle distance is smaller than said safe inter-vehicle distance; and

outputting means responsive to said signal for outputting an operation signal so as to operate the collision preventing means.

3. A drive assist system for a vehicle having inter-vehicle distance calculating means for detecting a preceding vehicle running ahead of the vehicle and for calculating an inter-vehicle distance between the vehicle and the preceding vehicle, vehicle speed calculating means for calculating a vehicle speed of the vehicle, preceding vehicle speed calculating means for calculating a vehicle speed of the preceding vehicle based on the inter-vehicle distance and the vehicle speed of the vehicle, and collision preventing means for preventing a collision of the vehicle with the preceding-vehicle, said drive assist system comprising:

preceding vehicle deceleration calculating means for calculating a deceleration of the preceding vehicle based on the vehicle speed of the preceding vehicle;

preceding vehicle deceleration judging means for making a judgment of whether or not said deceleration of the preceding vehicle is larger than a specified reference value;

leeway time calculating means for calculating a leeway time based on said judgment;

safe inter-vehicle distance establishing means for establishing a safe inter-vehicle distance between the vehicle and the preceding vehicle at least based on a multiplication of said leeway time and the vehicle speed of the vehicle;

inter-vehicle distance comparing means for comparing the inter-vehicle distance with said safe inter-vehicle distance and for outputting a signal when the inter-vehicle distance is smaller than said safe inter-vehicle distance; and

outputting means responsive to said signal for outputting an operation signal so as to operate the collision preventing means.

4. A drive assist method for a vehicle having an inter-vehicle distance calculating apparatus for detecting a preceding vehicle running ahead of the vehicle and for calculating an inter-vehicle distance between the vehicle and the preceding vehicle, a vehicle speed calculating apparatus for calculating a vehicle speed of the vehicle, a preceding vehicle speed calculating apparatus for calculating a vehicle speed of the preceding vehicle based on the inter-vehicle distance and the vehicle speed of the vehicle, and a collision preventing apparatus for preventing a collision of the vehicle with the preceding vehicle, the method comprising the steps of:

calculating a deceleration of the preceding vehicle based on the vehicle speed of the preceding vehicle;

calculating a leeway time responsive to said deceleration of the preceding vehicle;

establishing a safe inter-vehicle distance between the vehicle and the preceding vehicle at least based on a multiplication of said leeway time and the vehicle speed of the vehicle;

comparing the inter-vehicle distance with said safe inter-vehicle distance;

outputting a signal when the inter-vehicle distance is smaller than said safe inter-vehicle distance; and

outputting an operation signal in accordance with said signal so as to operate the collision preventing apparatus.

5. A drive assist method for a vehicle having an inter-vehicle distance calculating apparatus for detecting a preceding vehicle running ahead of the vehicle and for calculating an inter-vehicle distance between the vehicle and the preceding vehicle, a vehicle speed calculating apparatus for calculating a vehicle speed of the vehicle, a preceding vehicle speed calculating apparatus for calculating a vehicle speed of the preceding vehicle based on the inter-vehicle distance and the vehicle speed of the vehicle, and a collision preventing apparatus for preventing a collision of the vehicle with the preceding vehicle, the method comprising the steps of:

calculating a deceleration of the preceding vehicle based on the vehicle speed of the preceding vehicle;

making a judgment of whether or not said deceleration of the preceding vehicle is larger than a specified reference value;

calculating a leeway time in accordance with said judgment;

establishing a safe inter-vehicle distance between the vehicle and the preceding vehicle at least based on a multiplication of said leeway time and the vehicle speed of the vehicle;

comparing the inter-vehicle distance with said safe inter-vehicle distance;

outputting a signal when the inter-vehicle distance is smaller than said safe inter-vehicle distance; and

outputting an operation signal in accordance with said signal so as to operate the collision preventing apparatus.