Radar sensor and method for distance and cruise control

• US 7,554,485 B2
• Filed: 07/07/2005
• Issued: 06/30/2009
• Est. Priority Date: 09/28/2004
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Jordan, Ruediger
• Primary Examiner(s): Tarcza; Thomas H
• Assistant Examiner(s): GALT, CASSI J
• Application Number:
  US11/664,025
• Publication Number:
  US 20080106459A1
• Time in Patent Office: 1,454 Days
• Field of Search: 342 70- 72, 342/90, 342/192, 342/196, 342 94- 97, 701117-119, 701300-302
• US Class Current: 342/90
• CPC Class Codes: G01S 13/58 Velocity or trajectory determination systems; Sense-of-movement determination systems
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 17/58 Velocity or trajectory determination systems; Sense-of-movement determination systems
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 2013/93185 Controlling the brakes
• CPC Class Codes: G01S 2013/9319 Controlling the accelerator
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G01S 2013/9321 Velocity regulation, e.g. cruise control
• CPC Class Codes: G01S 2013/9325 for inter-vehicle distance regulation, e.g. navigating in platoons
• CPC Class Codes: G01S 7/411 Identification of targets based on measurements of radar reflectivity G01S7/415 takes precedence
• CPC Class Codes: G01S 7/4802 using analysis of echo signal for target characterisation; Target signature; Target cross-section

Abstract

A radar sensor and a corresponding method for distance and cruise control of a vehicle are described; using this sensor and method, objects in front of the vehicle in the direction of travel are detected and at least the variables: distance, relative velocity, and azimuth angle of the detected objects are ascertained with regard to the vehicle, the change over time of the reflection point of the radar beam on the object and classification of the detected object being determined as a function of the change over time of the reflection point.

Claims

1. A radar sensor for distance and cruise control of a motor vehicle, comprising:

an arrangement configured to detect objects in front of the vehicle in a direction of travel and to ascertain at least a distance, a relative velocity, an azimuth angle of a recognized object with regard to the vehicle, and a position of a reflection point of a radar beam on the object,

the arrangement further configured to ascertain a positional change in time of the reflection point of the radar beam on the object, and to ascertain a classification of the object as a function of the positional change in time of the reflection point.

2. The radar sensor as recited in claim 1, wherein the arrangement is further configured to ascertain a spatial extent of a change in the reflection point over a predetermined period of time.

3. The radar sensor as recited in claim 2, wherein the arrangement is further configured to ascertain the spatial extent based on changes over time in an ascertained azimuth angle of the reflection point.

4. The radar sensor as recited in claim 1, wherein the arrangement is further configured to calculate an instantaneous position of the object in advance from a previously ascertained object position and a previously ascertained relative velocity of the object, and to ascertain a spatial change of the reflection point from a deviation between the instantaneous object position and the object position calculated in advance.

5. The radar sensor as recited in claim 4, wherein the arrangement is further configured to compare an instantaneous position of the object with the instantaneous position of the object calculated in advance and to use a resulting difference from the comparison for object classification.

6. The radar sensor as recited in claim 1, wherein the arrangement is further configured to analyze a number of reflection points on the object for classification of the object.

7. The radar sensor as recited in claim 1, wherein the arrangement is further configured to assign the object to one of the following object classes:

passenger vehicle, truck, two-wheeled vehicle, manhole cover, guard rail, or other objects as part of the object classification.

8. A method for distance and cruise control of a vehicle comprising:

detecting an object in front of the vehicle in a direction of travel using a radar sensor;

ascertaining at least a distance, a relative velocity, an azimuth angle of the recognized objects with regard to the vehicle; and

a position of a reflection point of a radar beam on the object;

ascertaining a positional change over time in the reflection point of the radar beam on the object; and

ascertaining a classification of the detected object as a function of the positional change over time of the reflection point.

9. The method as recited in claim 8, wherein a spatial extent of the change of the reflection point is detected over a predetermined period of time.

10. The method as recited in claim 9, wherein the spatial extent is ascertained based on changes over time of ascertained azimuth angle of the reflection point.

11. The method as recited in claim 9, wherein an instantaneous position of the object is calculated in advance from a previously ascertained object position and a previously ascertained relative velocity of the object, and the spatial extent of the change of the reflection point is ascertained from a deviation in a instantaneous object position and the instantaneous calculated in advance.

12. The method as recited in claim 11, wherein the deviation in the instantaneous measured object position and the instantaneous position calculated in advance is compared and a resulting difference from the comparison is used for object classification.

13. The method as recited in claim 8, wherein a number of reflection points on the object is analyzed for classification of the object.

14. The method as recited in claim 10, wherein the object is assigned to one of the following object classes:

passenger vehicles, trucks, two-wheeled vehicles, manhole covers, guard rails, or other objects as part of an object classification.

15. The method as recited in claim 11, wherein a deviation in the instantaneous object position and the instantaneous object position calculated in advance undergoes Kalman filtering.

16. The method as recited in claim 15, wherein at least one of a Kalman filter deviation and the ascertained object class is used for more accurate advance calculation of a future position of the object from the instantaneously ascertained object position and the instantaneously ascertained relative velocity of the object.