Position-detecting and steering control system for moving vehicle

• US 5,031,101 A
• Filed: 10/11/1989
• Issued: 07/09/1991
• Est. Priority Date: 10/18/1988
• Status: Expired due to Fees

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Kamimura, Kenji, Tsuzuki, Sadachika
• Primary Examiner(s): Black, Thomas G.
• Application Number:
  US07/420,063
• Time in Patent Office: 636 Days
• Field of Search: 364/424.02, 364/424.01, 364/443, 364/449, 318/568.12, 180/168, 356/1
• US Class Current: 701/23
• CPC Class Codes: G05D 1/0244 using reflecting strips
• CPC Class Codes: G05D 1/0246 using a video camera in combination with image processing means
• CPC Class Codes: G05D 1/027 comprising intertial navigation means, e.g. azimuth detector inertial navigation G01C21/16; inertial navigation combined with non-inertial navigation instruments G01C21/165

Abstract

A steering control system for a moving vehicle wherein a light beam emitted from the moving vehicle is scanned along the circumferential direction thereof, and the light beam reflected by light-reflecting means disposed at at least three reference points is received to detect a position of the moving vehicle comprising, an azimuth detection means for detecting azimuths of the respective light-reflecting means, a position calculation means for calculating the position of the moving vehicle based on the azimuths detected, and a means for stopping travel of the moving vehicle when a following beam signal has not been detected over a predetermined period of time after detecting a preceding beam signal from a particular light reflecting means. It may comprise an azimuth prediction means for predicting an azimuth of the light-reflecting means to be detected in the next scanning cycle and an azimuth presumption means for presuming the azimuth of the light-reflecting means which is not detected when the light-reflecting means is not detected in the predicted azimuth.

Claims

1. A steering control system for a moving vehicle wherein a light beam emitted form the moving vehicle is scanned around an axis on the moving vehicle along the circumferential direction thereof, and the light beam is reflected by light-reflecting means disposed at at least three reference points around a working area in which said vehicle is moving, the reflected light being received at said axis on the vehicle to detect a position of the moving vehicle, said system comprising:

azimuth detection means for detecting the azimuths of the respective light-reflecting means with respect to an advance direction of the moving vehicle on the basis of a beam receiving interval of the light reflected by the light-reflecting means;

azimuth prediction means for predicting an azimuth of each light-reflecting means to be detected in a next scanning cycle based on the azimuth detected by the azimuth detection means during a given scanning cycle;

position calculation means for calculating the position of the moving vehicle based on the detected azimuths;

said position calculation means being operative to calculate the position of the moving vehicle based on a detected azimuth only when the detected azimuth of a light-reflecting means is in the azimuth predicted in the azimuth prediction means;

azimuth presumption means for presuming the azimuth of a light-reflecting means which is not detected when the light-reflecting means is not detected in the predicted azimuth; and

means for stopping travel of the moving vehicle when a following beam signal has not been detected over a predetermined period of time after detecting a preceding beam signal from a particular light reflecting means.

2. The steering control system for the moving vehicle as claimed in claim 1 wherein a lapse of the predetermined period of time is detected by means of a count value of clock signal in a counter.

3. The steering control system for the moving vehicle as claimed in claim 1 wherein a lapse of the predetermined period of time is detected by means of a predetermined travel distance of the moving vehicle.

4. The steering control system for the moving vehicle as claimed in claim 1 wherein a lapse of the predetermined period of time is detected by a timer circuit including a time constant circuit composed of a resistor and a capacitor.

5. The position-detecting system for the moving vehicle as claimed in claim 1 wherein the predicted azimuth has a predetermined range which is set on the basis of at least one azimuth which has been detected lastly.

6. The position-detecting system for the moving vehicle as claimed in claim 1 wherein a single light beam is scanned around the moving vehicle in one direction, and said reference points are detected in fixed order.

7. A position-detecting system for a moving vehicle wherein a single light beam emitted from the moving vehicle is scanned around an axis on the moving vehicle along the circumferential direction thereof, and the light beam is reflected in a fixed order by light-reflecting means disposed at at least three spaced reference points around a working area in which said vehicle is moving, the reflected light being received at said axis on the vehicle to detect a position of the moving vehicle, said system comprising:

azimuth detection means for detecting azimuths of the respective light-reflecting means with respect to an advance direction of the moving vehicle on the basis of a beam receiving interval of the light reflected by the light-reflecting means;

azimuth prediction means for predicting an azimuth of the light-reflecting means to be detected in the next scanning cycle based on the azimuth detected by the azimuth detection means;

position calculation means for calculating the position of the moving vehicle based on a detected azimuth when the detected azimuth of the light-reflecting means is in the azimuth predicted in the azimuth prediction means; and

azimuth presumption means for presuming the azimuth of a light-reflecting means which is not detected when the light-reflecting means is not detected in the predicted azimuth.

8. The position-detecting system for the moving vehicle as claimed in claim 7 further comprising means for stopping the moving vehicle when no detection of the light-reflecting means in the predicted azimuth continuously occurs a prescribed number of times.

9. The position-detecting system for the moving vehicle as claimed in claim 7 further comprising first counting means for counting the number of first successive detection cycles in which a particular light-reflecting means has not been detected in a predicted azimuth therefor;

setting means for setting a first prescribed number of times; and

means for stopping the moving vehicle when the number of first successive detection cycles exceeds the first prescribed number of times.

10. The position-detecting system for the moving vehicle as claimed in claim 9 further comprising second counting means for counting the number of second successive detection cycles in which a plurality of light-reflecting expected to be serially detected have not been detected serially in the respective predicted azimuthes therefor;

setting means for setting a second prescribed number of times; and

means for stopping the moving vehicle when the number of second successive detection cycles exceeds the second prescribed number of times.

11. The position-detecting system for the moving vehicle as claimed in claim 10 wherein the first prescribed number of times is larger than the second prescribed number of times.

12. The position-detecting system for the moving vehicle as claimed in claim 7 wherein the predicted azimuth has a predetermined range which is set on the basis of at least one azimuth which has been detected lastly.

13. The position-detecting system for the moving vehicle as claimed in claim 7 further comprising a counting means for counting the number of successive detection cycles in which a plurality of light-reflecting expected to be serially detected have not been detected serially in the respective predicted azimuthes therefor;

setting means for setting a prescribed number of times; and

means for stopping the moving vehicle when said number of successive detection cycles exceeds said prescribed number of times.

14. A position-detecting system for a moving vehicle wherein a light beam emitted from the moving vehicle is scanned around the moving vehicle along the circumferential direction thereof, and the light beam reflected by light-reflecting means disposed at at least three reference points is received to detect a position of the moving vehicle comprising:

azimuth detection means for detecting azimuths of the respective light-reflecting means with respect to an advance direction of the moving vehicle on the basis of a beam receiving interval of the light reflected by the light-reflecting means;

azimuth prediction means for predicting an azimuth of the light-reflecting means to be detected in the next scanning cycle based on the azimuth having been detected by the azimuth detection means; and

a means for stopping the moving vehicle when no detection of the light-reflecting means in the predicted azimuth continuously, occurs a prescribed number of times.