Method and system for determining driving environment

• US 6,686,869 B2
• Filed: 12/12/2002
• Issued: 02/03/2004
• Est. Priority Date: 12/18/2001
• Status: Expired due to Fees

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Inventors: Kim, Jee-Young
• Primary Examiner(s): Sotomayor, John B.
• Application Number:
  US10/318,604
• Publication Number:
  US 20030112174A1
• Time in Patent Office: 418 Days
• Field of Search: 342/70, 342/71, 342/72, 342/107, 342/113, 342/115
• US Class Current: 342/70
• CPC Class Codes: G01S 13/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S13/46
• 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 2013/93271 in the front of the vehicles
• CPC Class Codes: G01S 2013/93275 in the bumper area

Abstract

When a reflective wave reflected from a preceding object is received, the reflective wave being of an original radar beam scanned at a variable vertical angle, the vertical angle is detected, an absolute speed of the preceding object is calculated based on a vehicle speed and a relative speed calculated from the reflective wave, and accordingly a driving environment is determined based on the vertical angle and the absolute speed.

Claims

1. A method for determining vehicle driving environment, comprising:

scanning a radar beam from the vehicle at a variable vertical angle;

detecting a reflected wave from the radar beam being reflected from an object;

detecting the vertical angle of the radar beam when the reflected wave is detected;

calculating a relative speed of the object based on the reflected wave;

detecting a vehicle speed of the vehicle;

calculating an absolute speed of the object based on the relative speed and the vehicle speed;

comparing the vertical angle with a predetermined angle; and

comparing the absolute speed with a predetermined speed.

2. The method of claim 1, wherein:

the absolute speed of the object is calculated as a sum of the relative speed and the vehicle speed; and

the predetermined angle and the predetermined speed are respectively set to zero (0).

3. The method of claim 1 further comprising determining that an incline is in front of the vehicle or that the object is large, if the vertical angle is above the predetermined angle and the absolute speed is different from the predetermined speed.

4. The method of claim 1 further comprising determining that the object is stationary if the vertical angle is above the predetermined angle and the absolute speed is equal to the predetermined speed.

5. The method of claim 1 further comprising determining that a decline is in front of the vehicle if the vertical angle is below the predetermined angle and the absolute speed is different from the predetermined speed.

6. A vehicle driving environment determining system for detecting an object, the system comprising:

a radar for scanning a radar beam and detecting a reflected wave reflected from an object;

a mirror for adjusting a vertical angle of the scanned radar beam according to an angular position thereof;

a mirror angle detector for detecting the angular position of the mirror;

a stepper motor for adjusting the angular position of the mirror; and

an electronic control unit (ECU) programmed for;

calculating a relative speed of the object based on the reflected wave detected by the radar;

calculating an absolute speed of the object based on the relative speed and a vehicle speed of the vehicle;

detecting the vertical angle of the radar beam; and

comparing the vertical angle and the absolute speed with a predetermined angle and speed, respectively.

7. The system of claim 6, wherein:

the electronic control unit calculates the absolute speed of the vehicle as the sum of the relative speed and the vehicle speed; and

the predetermined angle and the predetermined speed are preset to 0.

8. The system of claim 6 wherein:

the radar, the stepper motor, the mirror angle detector, and the mirror are assembled as a module; and

the module is disposed at a bumper of the vehicle.

9. The system of claim 6, further comprising a vehicle speed detector.

10. A method for determining road grade from a vehicle, the method comprising:

projecting a radar from a vehicle toward an object, the object reflecting a radar wave back to the vehicle;

receiving the radar wave;

determining a first angle corresponding to the direction the radar was projected that resulted in the reflected radar wave;

calculating a relative speed of and a relative distance to the object based on the received radar wave;

determining a vehicle speed;

calculating an absolute speed of the object based on the vehicle speed and the relative speed;

comparing the absolute speed to zero speed;

comparing the first angle to a predetermined angle; and

determining a road grade, comprising;

concluding that either the road grade is positive, or that the object is large, if the first angle is above the predetermined angle and if the absolute speed is not zero speed;

concluding that the object is stationary if the first angle is above the predetermined angle and the absolute speed is zero speed; and

concluding that the road grade is negative if the first angle is below the predetermined angle and the absolute speed is not zero speed.

11. The method of claim 10, wherein the predetermined angle changes based on the relative distance.

12. The method of claim 10, wherein the projecting comprises scanning the radar horizontally and varying a vertical angle the radar is projected.

13. The method of claim 10, wherein the determining a road grade is only performed when the relative distance is in a predetermined range.

14. A system for determining road grade from a vehicle, the system comprising:

a radar for projecting from a vehicle and receiving reflected radar waves;

a rotatable mirror for varying an angle the radar is projected from the vehicle;

a mirror angle sensor for determining the angle;

a motor for rotating the mirror;

a vehicle speed sensor; and

at least one electronic control unit, said at least one electronic control unit being programmed with software for;

determining a first angle corresponding to the direction the radar was projected that resulted in the reflected radar wave;

calculating a relative speed of and a relative distance to the object based on the received radar wave;

determining a vehicle speed using the vehicle speed sensor;

calculating an absolute speed of the object based on the vehicle speed and the relative speed;

comparing the absolute speed to zero speed;

comparing the first angle to a predetermined angle; and

determining a road grade, comprising;

concluding that either the road grade is positive, or that the object is large, if the first angle is above the predetermined angle and if the absolute speed is not zero speed;

concluding that the object is stationary if the first angle is above the predetermined angle and the absolute speed is zero speed; and

concluding that the road grade is negative if the first angle is below the predetermined angle and the absolute speed is not zero speed.