Device, and associated method, for determining distances between moving objects

• US 5,617,199 A
• Filed: 04/26/1995
• Issued: 04/01/1997
• Est. Priority Date: 04/26/1995
• Status: Expired due to Term

• Current Assignee: Kama-Tech (HK) Limited
• Original Assignee: Laser Technology Incorporated (Laser Technology)
• Inventors: Dunne, Jeremy G.
• Primary Examiner(s): Buczinski, Stephen C.
• Application Number:
  US08/429,110
• Time in Patent Office: 706 Days
• Field of Search: 356/3.01-5.15, 356/28, 356/28.5, 180/169
• US Class Current: 356/5.01
• CPC Class Codes: B60Q 9/008 for anti-collision purposes
• CPC Class Codes: G01S 17/10 using transmission of interrupted, pulse-modulated waves determination of distance by phase measurements G01S17/32
• CPC Class Codes: G01S 17/46 Indirect determination of position data
• CPC Class Codes: G01S 17/58 Velocity or trajectory determination systems; Sense-of-movement determination systems
• CPC Class Codes: G08G 1/0175 by photographing vehicles, e.g. when violating traffic rules

Abstract

A device, and an associated method, for determining separation distances separating motor vehicles travelling along a roadway. A separation distance separating the motor vehicles is calculated responsive to targeting the vehicles with a laser range finder and determining the speeds of the vehicles. From this information, the separation distances separating the motor vehicles can be calculated. If the separation distance separating the motor vehicles is less than a minimum distance, then the calculated separation distance can be utilized by traffic enforcement officials to take appropriate enforcement actions.

Claims

1. A device for determining a value that is representative of a separation distance that separates first and second moving objects, said device comprising:

a range determiner positioned at a remote position remote from the first and second moving objects, said range determiner for determining a first range between the remote position and the first moving object wherein said first range is determined at a first time, and for determining a second range between the remote position and the second moving object wherein said second range is determined at a second time;

a speed determiner for determining values of speed of at least one of the first moving object and the second moving object; and

calculating circuitry operative responsive to the first range and the second range determined by said range determiner, the values of speed determined by said speed determiner, and an elapsed time interval between the first time and the second time at which the determinations of the first range and the second range are determined by said range determiner, said calculating circuitry for calculating values representative of the separation distance that separates the first and second moving objects.

2. The device of claim 1 wherein said calculating circuitry comprises processing circuitry having algorithms executable therein for calculating the separation distance separating the first and second moving objects.

3. The device of claim 1 further comprising an indicator coupled to said separation distance calculating circuitry, said indicator for indicating the separation distance calculated by said separation distance calculating circuitry in human perceptible form.

4. The device of claim 1 wherein the first and second moving objects comprise first and second motor vehicles, said device further comprising a memory element for storing data therein representative of permitted separation distances between the first and second moving vehicles travelling at at least one speed.

5. The device of claim 4 wherein the data stored in said memory element comprises data representative of permitted separation distances between the first and second moving vehicles travelling at a plurality of different speeds.

6. The device of claim 4 wherein the data stored in said memory element comprises data representative of permitted separation distances in a plurality of different jurisdictions between the first and second moving vehicles.

7. The device of claim 4 further comprising a comparator coupled to receive the data stored in said memory element and coupled to receive the separation distance calculated by said calculating circuitry, said comparator for comparing values of the data with values of the separation distance and for generating an annunciation signal when the value of the separation distance is less than the value of the data.

8. A device for determining a value representative of a separation distance separating first and second moving objects, said device comprising:

a laser range finder positioned at a remote position remote from the first and second moving objects, said laser range finder for determining a first range between the remote position and the first moving object and for determining a second range between the remote position and the second moving object;

a speed determiner for determining values of speed of at least one of the first moving object and the second moving object; and

calculating circuitry operative responsive to the first range and the second range calculated by said laser range finder, the speeds determined by said speed determiner, and an elapsed time between determinations of the first range and the second range determined by said laser range finder, said calculating circuitry for calculating values representative of the separation distance separating the first and second moving objects.

9. The device of claim 8 wherein said laser range finder further comprises processing circuitry coupled to said laser range finder, said processing circuitry having algorithms executable therein for calculating the first range and the second range.

10. The device of claim 8 wherein said speed determiner comprises processing circuitry coupled to said laser range finder determiner, said processing circuitry having algorithms executable therein for calculating the values of speed of the at least one of the first moving object and the second moving object.

11. The device of claim 9 wherein said processing circuitry is further operative to determine the elapsed time between the determinations of the first range and the second range.

12. A method for determining a value representative of a separation distance separating first and second moving objects, said method comprising the steps of:

determining a first range between a measuring position located remote from both the first and the second moving objects and the first moving object, said first range being determined at a first time;

determining a second range between the measuring position and the second moving object, said second range being determined at a second time;

determining values of speed of at least one of the first moving object and the second moving object; and

calculating the value representative of the separation distance separating the first and second moving objects based upon said first range, said second range, a time interval that exists between said first time and said second time, and said values of speed of at least one of the first moving object and the second moving object.

13. The method of claim 12 comprising the further step of indicating in human perceptible form the value representative of the separation distance calculated during said step of calculating.

14. The method of claim 12 wherein the first and second moving objects comprise first and second motor vehicles and wherein the method comprises the further step of storing data representative of permitted separation distances between the first and second moving vehicles travelling at at least one speed.

15. The method of claim 14 comprising the further steps of:

comparing the data stored during said step of storing with the value representative of the separation distance calculated during said step of calculating; and

generating an annunciation signal when the value representative of the separation distance is of a value less than a value of the data.

16. In a laser range finder and speed detector for determining ranges between a measuring position and a least first and second moving objects and for determining speeds of the at least first and second moving objects, an improvement of a circuit for determining values representative of a separation distance separating the first and second moving objects, said circuit comprising:

separation distance calculating circuitry operative responsive to the ranges between the measuring position and the first and second moving objects, the speed of at least one of the first and second moving objects, and an elapsed time between times at which the ranges between the measuring position and the first and second moving objects, said separation distance calculating circuitry for calculating the values representative of the separation distance separating the first and second moving objects.