Driver emulative vehicle control system

• US 5,684,697 A
• Filed: 06/26/1995
• Issued: 11/04/1997
• Est. Priority Date: 06/26/1995
• Status: Expired due to Fees

• Current Assignee: Charles H. Mullen
• Original Assignee: Charles H. Mullen
• Inventors: Mullen, Charles H.
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): WALDER, STEPHEN JOSEPH
• Application Number:
  US08/494,972
• Time in Patent Office: 862 Days
• Field of Search: 364/426.01, 364/424.027, 364/424.033, 364/426.016, 364/426.041, 364/426.044
• US Class Current: 701/28
• CPC Class Codes: G05D 1/0246 using a video camera in combination with image processing means
• CPC Class Codes: G05D 1/0263 using magnetic strips
• CPC Class Codes: G05D 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30

Abstract

A driver emulative vehicle control system for use with a vehicle. The vehicle control system includes a video camera which transduces the field of view into a plurality of scan lines each comprising a plurality of pixels. A digitizer serves to digitize the frames from the video camera. A computer inputs the digitized frames and processes the same to control the steering, acceleration, deceleration, and braking of the vehicle. More particularly, the processing means includes addressing means, steering control processing means, and speed control processing means. The addressing means serves to map the digitized frames into a mapping memory which is read by the steering control processing means and the speed control processing means. With reference to a lane stripe or stripes in the field of view, the steering control processing means determines the location of the vehicle and generates a steering control signal corresponding thereto. A steering control means receives the steering control signals and controls the steering shaft of the vehicle in accordance therewith. The speed control processing means determines the presence and location of a leading vehicle in the lane and generates speed control signals corresponding thereto. A speed control means serves to receive the speed control signals and to control the throttle control and/or brake of the vehicle.

Methods for automatically controlling the steering as well as the acceleration, deceleration and braking of a vehicle are also disclosed.

Claims

1. A driver emulative vehicle control system for use with a vehicle, the vehicle to be driven in a lane defined by a first lane stripe and a second lane stripe and of the type having a steering shaft, a throttle control, a brake, and a turn signal, said vehicle control system comprising:

a) a video camera which transduces light variations in a prescribed field in front of the vehicle into frames of electrical variations, each of said frames comprising a plurality of scan lines, said scan lines each comprising a plurality of pixels;

b) a digitizer electrically connected with said video camera and operative to digitize said frames of electrical variations;

c) a computer electrically connected with said digitizer, said computer operative to receive said digitized frames and having processing means, said processing means including;

i) addressing means operative to create an image in a mapping memory such that each pixel of each frame is addressed by a scan line number and a pixel number;

ii) steering control processing means operative to read said mapping memory, to determine for each frame the location of the first lane stripe with respect to the vehicle, and to generate steering control signals corresponding to the determined locations of the first lane stripe; and

iii) speed control processing means operative to read said mapping memory, to determine for each frame the presence and location with respect to the vehicle of a leading vehicle in the lane, and to generate speed control signals corresponding to the determined locations of the leading vehicle;

d) steering control means operative to receive said steering control signals and to control the steering shaft of the vehicle in accordance with said steering control signal; and

e) speed control means operative to receive said speed control signals and to control at least one of the throttle control and the brake of the vehicle.

2. The vehicle control system of claim 1 wherein said steering control means comprises a motor operative in response to said steering control signals to turn the steering shaft of the vehicle.

3. The vehicle control system of claim 2 wherein said steering control means further includes an electromagnetic clutch fixedly mounted on the steering shaft, a driven gear rotatably mounted on the steering shaft, and a drive gear mounted for rotation by said motor and intermeshed with said driven gear, wherein said electromagnetic clutch is selectively energizeable and de-energizeable, and wherein, when said electromagnetic clutch is energized, said electromagnetic clutch engages said driven gear and, when said electromagnetic clutch is de-energized, said electromagnetic clutch disengages from said driven gear.

4. The vehicle control system of claim 3 wherein said electromagnetic clutch is de-energized by actuation of the vehicle turn signal.

5. The vehicle control system of claim 1 wherein said speed control means includes brake control means operative to control the actuation of the vehicle'"'"'s brake.

6. The vehicle control system of claim 5 wherein said brake control means includes a servo actuator interconnected with a brake pedal and operative to control the position of the brake pedal.

7. The vehicle control system of claim 5 wherein said speed control means further includes means for controlling the throttle control of the vehicle.

8. The vehicle control system of claim 1 wherein said speed control means includes means for controlling the throttle control of the vehicle.

9. The vehicle control system of claim 1 wherein said steering control processing means is operative to determine the location of the first lane stripe with respect to the vehicle by first determining whether a first sensing pixel is present on a first reference scan line and, if said first sensing pixel is present, determining the distance between said first sensing pixel and a first reference pixel, and, if no first sensing pixel is present on said first reference scan line, locating a second sensing pixel on a second reference scan line and determining the distance between said second sensing pixel and a second reference pixel.

10. The vehicle control system of claim 1 wherein said speed control processing means is operative to determine a following distance for each frame corresponding to the distance between the vehicle and the leading vehicle, and is further operative to determine a closing rate between the vehicle and the leading vehicle as a function of the difference between the determined following distances of consecutive frames.

11. The vehicle control system of claim 10 wherein the speed control processing means is operative to generate a braking signal proportional to a prescribed value, said prescribed value corresponding to the instantaneous following distance and the instantaneous closing rate of the vehicle.

12. The vehicle control system of claim 1 wherein said speed control processing means includes means for determining the speed of the vehicle and is operative to determine a following distance corresponding to the distance between the vehicle and the leading vehicle, said speed control processing means operative to generate a brake signal when a prescribed relationship between the speed of the vehicle and the following distance is within a prescribed braking region, said speed control processing means operative to generate a decelerate signal when said prescribed relationship is within a prescribed decelerating region, said speed control processing means operative to generate an accelerate signal when said prescribed relationship is within a prescribed accelerating region.

13. A method for automatically controlling the steering of a vehicle in a lane, said method comprising:

a) inputting a video image comprising a plurality of scan lines, each of the scan lines comprising a plurality of pixels;

b) digitizing the video image;

c) counting and addressing each of the scan lines and pixels of the video image into a mapping memory;

d) determining whether a first reference scan line is intersecting a solid lane stripe;

e) if the first reference scan line is not intersecting a lane stripe, determining the scan line representing the portion of the video image closest to the vehicle which does intersect a solid lane stripe and identifying a first sensing pixel;

f) if the reference scan line is intersecting a solid lane stripe, identifying the first sensing pixel on the reference scan line;

g) determining the number of pixels between the first sensing pixel and a center pixel;

h) calculating a deviation from the center of the lane as a function of the number of pixels between the first sensing pixel and the center pixel; and

i) generating a deviation signal corresponding to the calculated deviation.

14. A method for automatically controlling the acceleration, deceleration, and braking of a vehicle, said method comprising the steps of:

a) inputting a video image comprising a plurality of scan lines;

b) digitizing the video image;

c) addressing the scan lines of the video image into a mapping memory;

d) determining whether a leading vehicle is present in the video image;

e) identifying a nearest scan line which intersects the leading vehicle;

f) determining the actual following distance between the vehicle and the leading vehicle corresponding to the number of the nearest scan line which detects the leading vehicle by reference to a look-up file;

g) if the actual following distance exceeds a prescribed maximum following distance, setting the actual following distance equal to the prescribed maximum following distance;

h) calculating an instantaneous closing rate as equal to the difference between a previous following distance and a current following distance divided by the time between respective video images;

i) determining an appropriate action as a function of the calculated closing rate; and

j) generating a control signal corresponding to the determined appropriate action to at least one of a vehicle cruise control module and a brake actuator.

15. The method of claim 14 wherein said step of determining an appropriate action as a function of the calculated closing rate further includes determining the appropriate action as a function of a vehicle speed and a speed limit.

16. A vehicle control system for use with a vehicle having a steering mechanism and a brake, comprising:

a) video means for inputting frames of a field of view;

b) a computer for receiving and processing said frames, said computer including;

i) addressing means for addressing said frames;

ii) steering control processing means for generating steering control signals corresponding to the location of the vehicle in a lane; and

iii) speed control processing means for generating speed control signals corresponding to the location of a leading vehicle;

c) steering control means for controlling the steering mechanism of the vehicle in accordance with the steering control signals; and

d) speed control means for controlling the speed and brake of the vehicle in accordance with the speed control signals.

17. A driver emulative vehicle control system for use with a vehicle, the vehicle to be driven in a lane defined by a first lane stripe and a second lane stripe and of the type having a steering shaft and a turn signal, said vehicle control system comprising:

a) a video camera which transduces light variations in a prescribed field in front of the vehicle into frames of electrical variations, each of said frames comprising a plurality of scan lines, said scan lines each comprising a plurality of pixels;

b) a digitizer electrically connected with said video camera and operative to digitize said frames of electrical variations;

c) a computer electrically connected with said digitizer, said computer operative to receive said digitized frames and having processing means, said processing means including;

i) addressing means operative to create an image in a mapping memory such that each pixel of each frame is addressed by a scan line number and a pixel number; and

ii) steering control processing means operative to read said mapping memory, to determine for each frame the location of the first lane stripe with respect to the vehicle, and to generate steering control signals corresponding to the determined locations of the first lane stripe; and

d) steering control means operative to receive said steering control signals and to control the steering shaft of the vehicle in accordance with said steering control signal.

18. The vehicle control system of claim 17 wherein said steering control means comprises a motor operative in response to said steering control signals to turn the steering shaft of the vehicle.

19. The vehicle control system of claim 18 wherein said steering control means further includes an electromagnetic clutch fixedly mounted on the steering shaft, a driven gear rotatably mounted on the steering shaft, and a drive gear mounted for rotation by said motor and intermeshed with said driven gear, wherein said electromagnetic clutch is selectively energizeable and de-energizeable, and wherein, when said electromagnetic clutch is energized, said electromagnetic clutch engages said driven gear and, when said electromagnetic clutch is de-energized, said electromagnetic clutch disengages from said driven gear.

20. The vehicle control system of claim 19 wherein said electromagnetic clutch is de-energized by actuation of the vehicle turn signal.

21. The vehicle control system of claim 17 wherein said steering control processing means is operative to determine the location of the first lane stripe with respect to the vehicle by first determining whether a first sensing pixel is present on a first reference scan line and, if said first sensing pixel is present, determining the distance between said first sensing pixel and a first reference pixel, and, if no first sensing pixel is present on said first reference scan line, locating a second sensing pixel on a second reference scan line and determining the distance between said second sensing pixel and a second reference pixel.

22. A driver emulative vehicle control system for use with a vehicle, the vehicle to be driven in a lane and of the type having a throttle control and a brake, said vehicle control system comprising:

a) a video camera which transduces light variations in a prescribed field in front of the vehicle into frames of electrical variations, each of said frames comprising a plurality of scan lines;

b) a digitizer electrically connected with said video camera and operative to digitize said frames of electrical variations;

c) a computer electrically connected with said digitizer, said computer operative to receive said digitized frames and having processing means, said processing means including;

i) addressing means operative to create an image in a mapping memory such that each scan line of each frame is addressed; and

ii) speed control processing means operative to read said mapping memory, to determine for each frame the presence and location with respect to the vehicle of a leading vehicle in the lane, and to generate speed control signals corresponding to the determined locations of the leading vehicle; and

d) speed control means operative to receive said speed control signals and to control at least one of the throttle control and the brake of the vehicle.

23. The vehicle control system of claim 22 wherein said speed control means includes brake control means operative to control the actuation of the vehicle'"'"'s brake.

24. The vehicle control system of claim 23 wherein said brake control means includes a servo actuator interconnected with a brake pedal and operative to control the position of the brake pedal.

25. The vehicle control system of claim 23 wherein said speed control means further includes means for controlling the throttle control of the vehicle.

26. The vehicle control system of claim 22 wherein said speed control means includes means for controlling the throttle control of the vehicle.

27. The vehicle control system of claim 22 wherein said speed control processing means is operative to determine a following distance for each frame corresponding to the distance between the vehicle and the leading vehicle, and is further operative to determine a closing rate between the vehicle and the leading vehicle as a function of the difference between the determined following distances of consecutive frames.

28. The vehicle control system of claim 27 wherein the speed control processing means is operative to generate a braking signal proportional to a prescribed value, said prescribed value corresponding to the instantaneous following distance and the instantaneous closing rate of the vehicle.

29. The vehicle control system of claim 22 wherein said speed control processing means includes means for determining the speed of the vehicle and is operative to determine a following distance corresponding to the distance between the vehicle and the leading vehicle, said speed control processing means operative to generate a brake signal when a prescribed relationship between the speed of the vehicle and the following distance is within a prescribed braking region, said speed control processing means operative to generate a decelerate signal when said prescribed relationship is within a prescribed decelerating region, said speed control processing means operative to generate an accelerate signal when said prescribed relationship is within a prescribed accelerating region.