VEHICLE OPTICAL GUIDANCE SYSTEM

• US 3,708,668 A
• Filed: 06/01/1971
• Issued: 01/02/1973
• Est. Priority Date: 06/01/1971
• Status: Expired due to Term

• Current Assignee: James W. Tilley
• Original Assignee: James W. Tilley
• Inventors: Tilley, James W.
• Primary Examiner(s): Borchelt, Archie R.
• Assistant Examiner(s): Nelms, D. C.
• Application Number:
  US05/148,584
• Time in Patent Office: 581 Days
• Field of Search: 250/202,220,208 180/97,98
• US Class Current: 250/202
• CPC Class Codes: G05D 1/0244 using reflecting strips

Abstract

A guidance system for a motor vehicle having a steering system including a plurality of photoelectric elements viewing an elongated strip transversely of the broken center line of a road; electronic circuitry including position-registers for receiving the input signal generated by the photoelectric elements and for producing output position signals corresponding to the new and old positions of the vehicle relative to the line; a comparator circuit for comparing the position signals to produce a control signal; and a control mechanism responsive to the control signal to restore the direction of the motor vehicle to a true course relative to the center line.

Claims

1. A guidance system for a vehicle adapted to travel on a road having a visible, broken directional line, comprising:

a. photoelectric means adapted to sense said directional line and to produce an electrical input signal corresponding to an interruption in the broken line viewed by said photoelectric means, b. first registering means adapted to be actuated by said input signal to produce a first output signal corresponding to the position of the vehicle relative to the broken line, c. second registering means adapted to be actuated by said input signal to produce a second output signal corresponding to the next previously produced first output signal to register the immediate past position of the vehicle relative to the broken line, d. means for comparing said first and second output signals to produce a control signal, and e. control means responsive to said control signal for maintaining said vehicle on a true course relative to said broken line.

2. The invention according to claim 1 in which said photoelectric means comprises a plurality of photoelectric elements mounted on the vehicle to view contiguous areas of the road disposed transversely of the directional line, so that only one element at a time views said directional line.

3. The invention according to claim 2 in which each photoelectric element comprises a view photoelectric element and further comprises a compensating photoelectric element operatively connected to each view photoelectric element to view the surface of the road not including a broken line, so that an input signal is produced only by the difference in light viewed by a view photoelectric element and its corresponding compensating photoelectric element.

4. The invention according to claim 2 in which said first registering means comprises a first register unit for each photoelectric element and said second registering means comprises a second register unit for each photoelectric element, said first register unit being adapted to receive the input signal from a corresponding photoelectric element, each second register unit being adapted to receive an output signal from a corresponding first register unit upon actuation by an input signal subsequent to the actuation of said corresponding first register unit by a previously produced input signal.

5. The invention according to claim 4 further comprising timing means responsive to said input signals for actuating said first and second register units.

6. The invention according to claim 5 in which said timing means is energized by an input signal to first actuate said second register units to receive any output signal from said corresponding first register units, and subsequently to actuate said first register units to receive any input signals from a corresponding photoelectric element.

7. The invention according to claim 2 in which said photoelectric means further comprises an amplifier and a monostable multivibrator connected in series with each of said photoelectric elements to produce said input signal when said photoelectric element views an interruption in said broken line, each of said monostable multivibrators being connected to said first registering means and to said second registering means.

8. The invention according to claim 7 in which said monostable multivibrator is turned on by a predetermined voltage generated by a photoelectric element viewing an interruption in said broken directional line, said monostable multivibrator remaining turned on for a period of time greater than the combined time for actuating said first registering means and said second registering means.

9. The invention according to claim 1 in which said comparing means comprises amplifier means for adding and comparing said first and second output signals.

10. The invention according to claim 9 in which said amplifier means comprises a first operational amplifier for receiving said first output signal, a second operational amplifier for amplifying said first output signal, a third operational amplifier for receiving and adding said second output signal and the output signal from said first amplifier, and a fourth operational amplifier for receiving and adding the output signals from said second and third amplifiers.