Safe distance algorithm for adaptive cruise control

• US 20020072843A1
• Filed: 08/16/2001
• Published: 06/13/2002
• Est. Priority Date: 08/16/2000
• Status: Active Grant

• Current Assignee: Valeo Radar Systems, Inc. (Valeo SE)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Woodington, Walter Gordon, Russell, Mark E., Delcheccolo, Michael Joseph, Firda, John Michael, Lippert, Delbert, Rees, H. Barteld Van
• Granted Patent: US 6,748,312 B2
• Time in Patent Office: Days
• US Class Current: 701/96
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: B60Q 9/008 for anti-collision purposes
• CPC Class Codes: B60T 2201/08 Lane monitoring; Lane Keeping Systems
• CPC Class Codes: B60T 2201/081 using distance control
• CPC Class Codes: B60T 2201/088 using transmission control
• CPC Class Codes: B60W 2530/10 Weight
• CPC Class Codes: B60W 2554/4043 Lateral speed
• CPC Class Codes: B60W 2554/803 Relative lateral speed
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle
• CPC Class Codes: G01S 13/04 Systems determining presence of a target based on relative movement of target G01S13/56
• CPC Class Codes: G01S 13/282 using a frequency modulated carrier wave G01S13/286 takes precedence
• CPC Class Codes: G01S 13/343 using sawtooth modulation
• CPC Class Codes: G01S 13/346 using noise modulation
• CPC Class Codes: G01S 13/48 using multiple beams at emission or reception
• CPC Class Codes: G01S 13/584 adapted for simultaneous range and velocity measurements
• CPC Class Codes: G01S 13/726 Multiple target tracking
• CPC Class Codes: G01S 13/87 Combinations of radar systems, e.g. primary radar and secondary radar
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/0245 Radar with phased array antenna
• CPC Class Codes: G01S 2013/9315 Monitoring blind spots
• CPC Class Codes: G01S 2013/9321 : Velocity regulation, e.g. cruise control
• CPC Class Codes: G01S 2013/93271 : in the front of the vehicles
• CPC Class Codes: G01S 2013/93272 : in the back of the vehicles
• CPC Class Codes: G01S 2013/93274 : on the side of the vehicles
• CPC Class Codes: G01S 2013/93275 : in the bumper area
• CPC Class Codes: G01S 7/023 : Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques auxiliary means for detecting or identifying radar signals or the like G01S7/021; means for anti-jamming G01S7/36
• CPC Class Codes: G01S 7/0232 : Avoidance by frequency multiplex
• CPC Class Codes: G01S 7/032 : Constructional details for solid-state radar subsystems
• CPC Class Codes: G01S 7/038 : Feedthrough nulling circuits
• CPC Class Codes: G01S 7/06 : Cathode-ray tube displays or other two dimensional or three-dimensional displays
• CPC Class Codes: G01S 7/288 : Coherent receivers
• CPC Class Codes: G01S 7/352 : Receivers
• CPC Class Codes: G01S 7/354 : Extracting wanted echo-signals Doppler systems G01S13/50
• CPC Class Codes: G01S 7/356 : involving particularities of FFT processing
• CPC Class Codes: G01S 7/4004 : of parts of a radar system
• CPC Class Codes: G01S 7/4008 : of transmitters
• CPC Class Codes: G01S 7/4021 : of receivers
• 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 1/3258 : using the gutter of the vehicle; Means for clamping a whip aerial on the edge of a part of the vehicle
• CPC Class Codes: H01Q 1/3283 : side-mounted antennas, e.g. bumper-mounted, door-mounted mounted on windscreens H01Q1/1271
• CPC Class Codes: H01Q 1/38 : formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 1/42 : Housings not intimately mechanically associated with radiating elements, e.g. radome
• CPC Class Codes: H01Q 13/10 : Resonant slot antennas
• CPC Class Codes: H01Q 13/18 : the slot being backed by, or formed in boundary wall of, a resonant cavity longitudinally slotted cylinder H01Q13/12 ; Open cavity antennas
• CPC Class Codes: H01Q 21/0043 : Slotted waveguides combination with horns H01Q13/0233
• CPC Class Codes: H01Q 21/0075 : Stripline fed arrays H01Q21/065 takes precedence
• CPC Class Codes: H01Q 21/0087 : Apparatus or processes specially adapted for manufacturing antenna arrays manufacturing waveguides H01P11/00
• CPC Class Codes: H01Q 21/065 : Patch antenna array
• 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 3/24 : varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching
• 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.