METHOD AND APPARATUS FOR DIGITALLY DETERMINING THE SPEED OF A MOVING OBJECT

• US 3,689,921 A
• Filed: 04/24/1970
• Issued: 09/05/1972
• Est. Priority Date: 04/24/1970
• Status: Expired due to Term

• Current Assignee: Kustom Signals Incorporated (MPD Incorporated)
• Original Assignee: Fred M. Berry
• Inventors: Fred, M. Berry
• Primary Examiner(s): T. H. Tubbesing
• Application Number:
  US05/031,609
• Time in Patent Office: 865 Days
• Field of Search: 343/5DP,8
• US Class Current: 342/115
• CPC Class Codes: G01S 13/585 processing the video signal in order to evaluate or display the velocity value

Abstract

A digital display Doppler radar unit has a crystal control time base and a means for correlating received Doppler signals, indicative of speed, with the time base. A digital counter counts the cycles of the received Doppler signal and compares the count with an amount (either 0 or more) previously stored. Circuit means are provided to validate the received Doppler signals only after a preselected number of valid comparisons are made and the speed corresponding to the valid received Doppler signals are displayed and/or a speed alarm sounded.

Claims

1. A Doppler radar device for determining the speed of a moving object, said device comprising:

means for producing a continuously running time base, means for receiving a Doppler signal, means for correlating said received Doppler signal with said time base, means for counting cycles of said correlated Doppler signal, said correlating means and said Doppler signal counting means cooperating to count said cycles of said Doppler signal in a preselected time increment, said time increment relating to said time base, and means for displaying the number of Doppler signal cycles in units indicative of the speed of said moving object.

2. The invention as in claim 1 including means for comparing a plurality of total counts of said Doppler signal prior to displaying a number as being indicative of the speed of said moving object.

3. The invention as in claim 2 including means for blanking said display means when a preselected number of counts did not compare.

4. The invention as in claim 3 including means for resetting said counting means to zero after each comparison.

5. The invention as in claim 2 wherein said comparing means includes means for requiring a preselected number of comparisons prior to said indicating of said count total as being a valid speed, said preselected number being sufficient to substantially eliminate noise and/or reflections as having an effect on said displayed speed.

6. The invention as in claim 1 wherein said correlating means includes a gate circuit interconnected with said time base and said receiving means, said gate circuit utilizing the first cycle of said Doppler signal to synchronize said received signal with said time base.

7. The invention as in claim 6 including means for establishing a time period corresponding to said time base, wherein said counting means includes a digital counter operable to count said cycles of said Doppler signal after said first cycle within said time period, said displaying means operable to display the number of counted Doppler signal cycles within said time period and to indicate same as the speed of said moving object.

8. The invention as in claim 7 including means for comparing a plurality of total counts of said Doppler signal prior to displaying a number as being indicative of the speed of said moving object.

9. The invention as in claim 7 wherein said comparing means includes a means for requiring a preselected number of comparisons prior to indicating said count total as valid, said preselected number being sufficient to substantially eliminate noise and/or reflections as having an effect on said displayed speed.

10. The invention as in claim 1 wherein said time base is established by an oscillator having a preselected precise frequency, a time increment counter, said correlating means including a gate circuit interconnected with said receiving means and said time increment counter, said gate circuit operable to synChronize the start of a time period counted by said time increment counter with said received Doppler signal, said time increment counter being operable to count said oscillator output cycles for the establishment of said timing period.

11. The invention as in claim 10 wherein said counting means includes a digital counter interconnected with said gate circuit and said time increment counter, said digital counter operable to count said synchronized Doppler signal cycles within said timing period.

12. The invention as in claim 11 including a storage register, a comparator circuit, said comparator circuit operable to compare the count in said digital counter with the count in said storage register, and means for requiring a preselected number of valid comparisons before said count in said storage register will be displayed in units indicative of the speed of said moving object.

13. The invention as in claim 12 including means for presetting a particular speed count, and means for giving an indication when said validated speed count is equal to or exceeds said preset speed count.

14. The invention as in claim 13 including means for precluding the change of said displayed speed after said indicating means has indicated a speed count equal to or in excess of said preset speed count.

15. The invention as in claim 12 including means for sounding a violation warning tone when said validated speed count is equal to or exceeds said preset speed count.

16. A Doppler radar device for determining the speed of a moving object, said device comprising a time base, means for receiving a Doppler signal, a gate circuit interconnected with said time base and said receiving means, said gate circuit utilizing the first cycle of said Doppler signal to synchronize said received signal with said time base, means for establishing a time period corresponding to said time base, a counter, said counter operable to count the cycles of said Doppler signal after said first cycle within said time period, and means for displaying the number of counted Doppler signal cycles within said time period in units indicative of the speed of said moving object.

17. The invention as in claim 16 including means for comparing a plurality of total counts of said Doppler signal prior to displaying a number as being indicative of the speed of said moving object.

18. The invention as in claim 17 wherein said comparing means includes a means for requiring a preselected number of comparisons prior to indicating said count total as valid, said preselected number being sufficient to substantially eliminate noise and/or reflections from having an effect on said displayed speed.

19. The invention as in claim 18 wherein said time base is derived from a continuously running oscillator having a precise frequency, and wherein said means for establishing a time period includes a time increment counter, said time increment counter starting said time period after said first cycle and ending said time period within a preselected time, said time increment counter having means associated therewith for producing a plurality of sequentially occurring pulses immediately prior to the end of said time period.

20. A Doppler radar device for determining the speed of a moving vehicle, said device comprising:

means for producing a continuously running time base said producing means including a precise high frequency reference signal having countable periods, a counter connected with said reference signal and operable to count a preselected number of said periods, said counted periods thereby corresponding to a precise time increment for said time base, means for receiving a Doppler signal, means for correlating said received Doppler signal with said time base, means for counting the cycles of said correlated Doppler signal, and means for displaying the number of Doppler cycles in units indicative of the speed of said moving vehicle.

21. A method for determining the speed of a moving object, said method comprising the steps of digitally producing a precise time base, receiving a Doppler signal, digitally correlating said received Doppler signal with said time base, counting the cycles of said correlated Doppler signals, and displaying the number of counted correlated cycles of said Doppler signals in terms of speed of said moving object.

22. The method as in claim 21 including the steps of establishing a timing period and performing said counting step within said timing period.

23. The method as in claim 22 including comparing a plurality of total counts of said Doppler signal received within said time period prior to displaying a number as being indicative of a valid speed of said moving object.

24. The method as in claim 23 including the step of requiring a preselected number of comparisons prior to indicating said count total as valid, said preselected number being sufficient to substantially eliminate noise as having an effect on said displayed speed.

25. The invention as in claim 24 including the steps of presetting a preselected speed count on a device, and indicating a validated speed count that is equal to or in excess of said preset speed count as a violation.

26. The invention as in claim 25 including the step of sounding an audible warning tone when said validated speed count exceeds said preset speed count.

27. The invention as in claim 25 including the step of precluding the changing of said validated displayed speed count that is equal to or in excess of said preset speed count.

28. The method as in claim 23 including the step of blanking said display means when a preselected number of counts did not compare during said comparison step.

29. The method as in claim 23 including the step of resetting said counting step to a zero count after each comparison step.

30. The method as in claim 23 including the step of changing said time period to correspond to counts at the transition.