Distance measuring system

• US 4,268,167 A
• Filed: 01/08/1979
• Issued: 05/19/1981
• Est. Priority Date: 01/08/1979
• Status: Expired due to Term

• Current Assignee: Robert J. Alderman
• Original Assignee: Robert J. Alderman
• Inventors: Alderman, Robert J.
• Primary Examiner(s): Buczinski, Stephen C.
• Application Number:
  US06/001,582
• Time in Patent Office: 862 Days
• Field of Search: 356/1, 356/4, 343/112 D
• US Class Current: 356/3.09
• CPC Class Codes: G01S 11/02 using radio waves G01S19/00 takes precedence
• CPC Class Codes: G01S 11/04 using angle measurements
• CPC Class Codes: G01S 11/12 using electromagnetic waves other than radio waves

Abstract

System for measuring the distance between a central location and any number of remote locations. Two parallel beams of radiation emanate outwardly from the central location, and the beams are rotated at a known angular velocity. The time required for each of the two beams of radiation to sweep past a given point at a remote location is a function of the distance which separates the remote location from the central location, and that time can be determined at the remote location to indicate the separation distance. The beams of radiation may be parallel beams, or alternatively the beams may diverge at a known fixed angle that does not originate at the point of rotation.

Claims

1. System for determining the distance between a first location and a second location, comprising:

means at said first location for providing a pair of separate beams of radiation which have a predetermined angular relation to each other and which traverse said second location at a predetermined angular velocity;

said beams of radiation rotating about an axis of rotation at said first location; and

said beams diverging at a fixed angle in relation to a point of divergence which is not coincident with said axis of rotation;

means at said second location for detecting the presence of said beams of radiation; and

means at said second location responsive to said detecting means to provide a signal corresponding to the elapsed time between detection of said separate beams as said pair of beams traverses the second location.

2. The system as in claim 1, wherein said beams of radiation rotate about an axis substantially perpendicular to a plane occupied by said first and second locations.

3. The system as in claim 1, wherein said beams rotate about said axis in unison and at a constant velocity.

4. The system as in claim 1, wherein said detecting means is operative to indicate the presence of each of said beams only in response to the detected presence of said radiation at a predetermined threshold intensity, so that said elapsed time is determined by the time for said detection means to be traversed by said threshold intensity of each beam of said pair of beams.

5. The system as in claim 4, wherein said means at said first location is operative to provide said pair of beams having substantially equal intensity.

6. The system as in claim 1, wherein said beams of radiation rotate about said axis in unison and at a constant angular velocity.

7. The system as in claim 1, wherein said beams of radiation rotate about said axis at a known angular acceleration for a certain angular displacement.

8. System for determining the distance between a first location and a second location, comprising:

means at said frst location for providing a pair of separate beams of radiation which have a predetermined angular relation to each other and which traverse said second location at a predetermined angular velocity;

means at said first location operative in response to the actual angular velocity of said beams of radiation to transmit a control signal which is a function of said angular velocity;

means at said second location for detecting the presence of said beams of radiation;

means at said second location responsive to said detecting means to provide a signal corresponding to the elapsed time between detection of said separate beams as said pair of beams traverses the second location;

said means at said second location comprising clock means for producing clock pulses at a predetermined repetition rate;

said clock means being operative in response to said control signal to adjust the repetition rate of clock pulses so that said number of clock pulses counted during said traverse is unaffected by variations in said angular velocity;

means responsive to said timing signals and selectably operative to count said timing signals;

said counting means being responsive to said detecting means to count said timing signals only during the time in which said beams accomplish a predetermined traverse of said second location, so that the number of said timing signals counted by said counting means during said traverse corresponds to said distance between said first location and said second location; and

said means for providing timing signals is responsive to the angular velocity of said beams of radiation to provide said timing signals at an adjustable repetition rate determined by said angular velocity.