Optronic system for the measurement of vehicle traffic

• US 6,750,787 B2
• Filed: 03/13/2001
• Issued: 06/15/2004
• Est. Priority Date: 03/17/2000
• Status: Expired due to Fees

• Current Assignee: Herbert A. Hutchinson
• Original Assignee: Herbert A. Hutchinson
• Inventors: Hutchinson, Herbert A.
• Primary Examiner(s): Wu, Daniel J.
• Assistant Examiner(s): TANG, SON M
• Application Number:
  US09/805,691
• Publication Number:
  US 20020000921A1
• Time in Patent Office: 1,190 Days
• Field of Search: 340/933, 340/934, 340/935, 340/936, 340/942, 340/330, 701/117, 701/118, 701/119
• US Class Current: 340/942
• CPC Class Codes: G08B 13/183 by interruption of a radiation beam or barrier
• CPC Class Codes: G08G 1/04 using optical or ultrasonic detectors
• CPC Class Codes: G08G 1/056 with provision for distinguishing direction of travel

Abstract

The present invention is a vehicle traffic measurement system designed to accurately count and record the number of vehicles passing through a selected location, to more accurately determine and record the velocity at which the individual vehicles travel through that location, and to accurately determine and record in which relative direction the vehicles are traveling as they pass that location. The basic physical principle is of a moving object interrupting two parallel light beams a known reference distance apart, and information extracted from the interruptions sensed and electronically processed into count, direction, and velocity being recorded for subsequent data analysis.

Claims

1. An apparatus for measuring the speed, direction of travel and cumulative count of one or more moving vehicles in a stream of traffic comprising:

a. a beam emitter unit comprising at least two visible wavelength laser beam emitters wherein said laser beam emitters are mounted to generate two visible wavelength laser beams coplanar and parallel to each other and having a lateral separation distance between said laser beams of approximately one foot; and

b. a beam sensor unit comprising;

i. at least two laser beam sensors wherein said laser beam sensors are mounted to receive and distinguish the on/off status of said laser beams; and

ii. a beam status discriminator and a timer means for electronically pausing said beam status discriminator and electrical processing for a one second period after said status of said laser beams is interrupted off;

wherein said beam emitter unit and said beam sensor unit are each positioned to emanate said laser beams between about 4-8 inches above the surface of a roadway.

2. An apparatus according to claim 1 wherein said beam emitter unit comprises:

a. a first visible wavelength laser beam emitter;

b. a second visible wavelength laser beam emitter; and

c. a third visible wavelength laser beam emitter means for aligning said visible wavelength laser beams between said beam emitter unit and said beam sensor control unit.

3. A method of cumulatively counting a plurality of moving vehicles in a stream of traffic comprising the steps of:

providing an apparatus of claim 1;

interrupting either of two said visible wavelength laser beams generated across a roadway and sensed by said apparatus of claim 1 and electronically recording the sensed laser beam interruption;

processing the sequence and timing of the electronic events corresponding to said laser beam interruption via an electronic computer processor chip into a cumulative count of said moving vehicles; and

producing an electronic data readout in chronological sequence from said apparatus.

4. A method of determining the speed and direction of travel of one or more moving vehicles in a stream of traffic comprising the steps of:

providing an apparatus of claim 1;

interrupting a first visible wavelength laser beam generated by said apparatus of claim 1 and electronically recording said first laser beam interruption;

interrupting a second visible wavelength laser beam generated by said apparatus of claim 1 and electronically recording said second laser beam interruption;

processing the electronic events corresponding to the sequence of and the time interval between said first and second laser beam interruptions via an electronic computer processor chip into the vehicle direction of travel and vehicle speed; and

producing an electronic data readout in chronological sequence from said apparatus.