Safe distance algorithm for adaptive cruise control

• US 20030004633A1
• Filed: 08/12/2002
• Published: 01/02/2003
• Est. Priority Date: 03/14/2001
• Status: Active Grant

• Current Assignee: Valeo Radar Systems, Inc. (Valeo SE)
• Original Assignee: Delbert Lippert, H. Barteld Van Rees, John Michael Firda, Mark E. Russell, Michael Joseph Delcheccolo, Walter Gordon Woodington
• Inventors: Woodington, Walter Gordon, Firda, John Michael, Russell, Mark E., Delcheccolo, Michael Joseph, Van Rees, H. Barteld, Lippert, Delbert
• Granted Patent: US 6,708,100 B2
• Time in Patent Office: Days
• US Class Current: 701/96
• CPC Class Codes: G01S 13/584 adapted for simultaneous range and velocity measurements
• CPC Class Codes: G01S 2013/9321 Velocity regulation, e.g. cruise control
• CPC Class Codes: H01Q 1/3233 particular used as part of a sensor or in a security system, e.g. for automotive radar, navigation systems
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• CPC Class Codes: H01Q 3/40 with phasing matrix

Abstract

In accordance with the present invention, an adaptive cruise control system includes a radio frequency (RF) transmit receive (TR) sensor module (or more simply “sensor”) disposed such that a detection zone is deployed in front of a vehicle. The sensor includes a sensor antenna system which comprises a transmit antenna for emitting or transmitting an RF signal and a receive antenna for receiving portions of the transmitted RF signal which are intercepted by one or more objects within a field of view of the transmit antenna and reflected back toward the receive antenna. With this particular arrangement, a detection system that detects objects in a region about a front of a vehicle is provided. If the system determines that the vehicle is approaching an object or that an object is approaching the vehicle, then the sensor initiates steps that are carried out in accordance with a set of rules that control an accelerator of the vehicle. The accelerator is adjusted to maintain a safe trailing distance behind the detected object.

Claims

1. A method of providing adaptive cruise control comprising the steps of:

determining the speed of an object;

calculating a trailing distance between a vehicle and the object; and

adjusting the speed of the vehicle to maintain said trailing distance between the object and the vehicle.

2. The method of claim 1 wherein said step of calculating a trailing distance comprises the steps of:

determining a travel distance; and

adjusting said travel distance to account for a weight of said vehicle.

3. The method of claim 2 wherein said step of determining a travel distance comprises determining, from the speed of the object, the distance traveled by said object in a predetermined period of time.

4. The method of claim 3 wherein said predetermined period of time comprises approximately three seconds.

5. The method of claim 1 wherein said step of determining comprises the steps of:

transmitting a first RF signal;

receiving a second RF signal;

comparing said second RF signal with said first RF signal to determine a frequency difference, wherein said frequency difference is proportional to a distance between said object and said vehicle.

7. The method of claim 5 wherein said second RF signal comprises a reflection of said first RF signal.

8. The method of claim 5 wherein said first RF signal comprises a Frequency Modulated Continuous Wave (FMCW) signal.

9. The method of claim 1 wherein said vehicle is selected from the group comprising an automobile, a motorcycle, a truck, an aircraft, a marine vehicle, and an agricultural vehicle.

10. The method of claim 1 further comprising the step of upgrading said sensor.

11. The method of claim 1 further comprising the step of changing a coverage zone provided by said sensor

13. The adaptive cruise control system of claim 12 wherein said trailing distance comprises a travel distance which is adjusted to account for a weight of the vehicle.

14. The adaptive cruise control system of claim 13 wherein said travel distance comprises the distance traveled by said object in a predetermined period of time.

15. The adaptive cruise control system of claim 14 wherein said predetermined period of time comprises approximately three seconds.

16. The adaptive cruise control system of claim 12 wherein said the speed of the object is determined by comparing the second RF signal with said first RF signal to determine a frequency difference, wherein said frequency difference is proportional to a distance between said object and said vehicle.

17. The adaptive cruise control system of claim 12 wherein said sensor decreases the speed of the vehicle when a distance between the vehicle and the object is less than said trailing distance.

18. The adaptive cruise control system of claim 12 wherein said second RF signal comprises a reflection of said first RF signal.

19. The adaptive cruise control system of claim 12 wherein said first RF signal comprises a Frequency Modulated Continuous Wave (FMCW) signal.

20. The adaptive cruise control system of claim 12 wherein said vehicle is selected from the group comprising an automobile, a motorcycle, a truck, an aircraft, a marine vehicle, and an agricultural vehicle.

21. The adaptive cruise control system of claim 12 wherein said sensor is upgradeable.

22. The adaptive cruise control system of claim 12 wherein said sensor is capable of providing different coverage zones.

6. Method of clam 1 wherein said step of adjusting comprises decreasing the speed of the vehicle when a distance between the object and the vehicle is less than said trailing distance.

12. An adaptive cruise control system comprising:

a sensor for providing detection coverage in a predetermined coverage zone in front of a vehicle, the sensor comprising;

a transmit antenna for transmitting a first RF signal;

a receive antenna for receiving a second RF signal; and

a receiver circuit, coupled to said received antenna; and

an interface coupling said receiver circuit to an accelerator of the vehicle, and wherein said sensor determines the speed of an object in front of the vehicle, calculates a safe trailing distance behind the object in front of said vehicle, and adjusts the accelerator of the vehicle to maintain said safe trailing distance.