Collision warning system

• US 5,459,460 A
• Filed: 06/15/1993
• Issued: 10/17/1995
• Est. Priority Date: 12/11/1992
• Status: Expired due to Fees

• Current Assignee: Kansei Company
• Original Assignee: Kansei Company
• Inventors: Nishino, Jun
• Primary Examiner(s): Hofsass, Jeffery A.
• Application Number:
  US08/076,633
• Time in Patent Office: 854 Days
• Field of Search: 340/903, 340/438, 340/436, 340/435, 364/424.01, 364/424.04, 364/461, 180/170
• US Class Current: 340/903
• CPC Class Codes: B60Q 9/008 for anti-collision purposes
• CPC Class Codes: G01P 7/00 Measuring speed by integrating acceleration measuring travelled distance by double integration of acceleration G01C21/16
• CPC Class Codes: G01S 17/931 of land vehicles

Abstract

A collision warning system is mounted on a vehicle to issue an alarm when the vehicle approaches near an obstacle running in front of the vehicle. The system detects a speed (Vf) of the vehicle; a distance (R) between the vehicle and the obstacle; a speed (Va) of the obstacle using both the speed (Vf) of the vehicle and the distance (R). The collision warning system issues an alarm to a driver if the following relationship exists between the vehicle and the obstacle:

Vf×Td+(Vf-Va).sup.2 /2α≧R

wherein:

Td: a fixed time period, and

α: a braking performance of the vehicle.

Claims

1. A collision warning system mounted on a vehicle to issue an alarm when the vehicle approaches near an obstacle, said system comprising:

means for detecting the speed (Vf) of the vehicle;

means for measuring the distance (R) between the vehicle and the obstacle;

means for deriving a speed (Va) of the obstacle using both said speed (Vf) and said distance (R);

means for determining whether the following relationship exists between the vehicle and the obstacle;

space="preserve" listing-type="equation">Vf×

Td+(Vf-Va).sup.2 /2α

≧

R

wherein;

Vf;

said speed of the vehicle,

Td;

a time period,

Va;

said speed of the obstacle,

α

;

a braking performance of the vehicle,

R;

said distance between the vehicle and the obstacle;

and

means for issuing an alarm to the driver when said relationship exists.

2. A collision warning system as claimed in claim 1, further comprising means for setting said time period (Td) to zero when a brake pedal of the vehicle is depressed a given amount.

3. A collision warning system as claimed in claim 1, wherein said means for detecting said speed (Vf) of the vehicle is a vehicle speed sensor mounted on the vehicle.

4. A collision warning system as claimed in claim 3, wherein said means for measuring said distance (R) comprises a laser beam emitting device mounted on the vehicle.

5. A collision warning system as claimed in claim 4, wherein said means for deriving uses the following equation for the derivation of said speed (Va) of the obstacle:

space="preserve" listing-type="equation">Va=Vf-dR/dt

wherein;

Va;

said speed of the obstacle,

Vf;

said speed of the vehicle,

dR/dt;

relative speed between the vehicle and the obstacle.

6. A collision warning system as claimed in claim 1, wherein said time period (Td) is the time period which elapses from the time when a driver notices the issuance of the alarm to the time the driver actuates the brake pedal.

7. A collision warning system mounted on a vehicle to issue an alarm when the vehicle approaches near an obstacle in front of the vehicle, said system comprising:

means for setting a time period (Td) which elapses from a time when a driver notices a danger to a time when the driver actuates a brake pedal of the vehicle;

means for detecting the speed (Vf) of the vehicle;

laser beam emitting means for measuring the distance (R) between the vehicle and the obstacle;

means for deriving the speed (Va) of the obstacle using the following equation;

space="preserve" listing-type="equation">Va=Vf-dR/dt

wherein;

Va;

said speed of the obstacle,

Vf;

said speed of the vehicle,

dR/dt;

relative speed between the vehicle and the obstacle,

means for determining whether the following relationship exists between the vehicle and the obstacle;

space="preserve" listing-type="equation">Vf×

Td+(Vf-Va).sup.2 /2α

≧

R

wherein;

Vf;

said speed of the vehicle,

Td;

said time period,

Va;

said speed of the obstacle,

α

;

braking performance of the vehicle,

R;

said distance between the vehicle and the obstacle; and

alarm means for giving an alarm to the driver when the relationship exists.

8. A collision warning system mounted on a vehicle to issue an alarm when the vehicle approaches near an obstacle in front of the vehicle, said system comprising:

first means for setting a time period (Td) which elapses from a time when a driver notices a danger to a time when the driver actuates a brake pedal of the vehicle;

second means for detecting the speed (Vf) of the vehicle;

third means for measuring a distance (R) between the vehicle and the obstacle;

fourth means for deriving the speed (Va) of the obstacle using the following equation;

space="preserve" listing-type="equation">Va=Vf-dR/dt

wherein;

Va;

said speed of the obstacle,

Vf;

said speed of the vehicle,

dR/dt;

relative speed between the vehicle and the obstacle,

fifth means for determining whether the following relationship exists between the vehicle and the obstacle;

space="preserve" listing-type="equation">Vf×

Td+(Vf-Va).sup.2 /2α

≧

R

wherein;

Vf;

said speed of the vehicle,

Td;

said time period,

Va;

said speed of the obstacle,

α

;

braking performance of the vehicle,

R;

said distance between the vehicle and the obstacle;

sixth means for giving an alarm to the driver when said relationship exists; and

seventh means for setting said time period (Td) to zero when the brake pedal has been depressed before said fifth means determines whether said relationship exists.