Method and apparatus for determining the speed and location of a vehicle

• US 6,266,627 B1
• Filed: 07/16/1999
• Issued: 07/24/2001
• Est. Priority Date: 04/01/1996
• Status: Expired due to Term

• Current Assignee: Gatsometer B.V. (Sensys Gatso Group AB)
• Original Assignee: Tom Gatsonides
• Inventors: Gatsonides, Tom
• Primary Examiner(s): Shah, Kamini
• Assistant Examiner(s): Bui, Bryan
• Application Number:
  US09/155,624
• Time in Patent Office: 739 Days
• Field of Search: 702/142-143, 702/149-150, 702/159, 701/117, 701/119, 342/104-109, 342/128, 342/133, 340/933, 340/936, 340/937
• US Class Current: 702/143
• CPC Class Codes: G01S 13/582 adapted for simultaneous range and velocity measurements
• CPC Class Codes: G01S 13/92 for velocity measurement
• CPC Class Codes: G08G 1/054 photographing overspeeding vehicles

Abstract

Disclosed is a method and apparatus for measuring the speed of a vehicle by transmitting a wave beam directed at the vehicle, receiving a part of the wave beam reflected by the vehicle, comparing the reflected beam part with the transmitted wave beam and deriving from this comparison the speed of the vehicle, wherein during the speed measurement the position of the vehicle is also determined. A vehicle committing an offense can thus be identified unambiguously in a recording which is made after detection of the speeding offense. The speed of the vehicle can be determined from a difference in wavelength detected during the comparison between the reflected beam part and the transmitted wave beam, while the position of the vehicle is determined from a time lag detected during the comparison between the moment of transmitting and the moment of receiving the reflected beam part.

Claims

1. A method for measuring the speed of a vehicle comprising the steps of

transmitting a wave beam directed at the vehicle,

receiving a part of the wave beam reflected by the vehicle,

comparing the reflected beam part with the transmitted wave beam,

deriving from this comparison both the speed and the position of the vehicle,

comparing the measured speed with a maximum allowed speed, and

generating a warning signal when a speeding offense is determined,

wherein the position of the vehicle is determined from a time lag detected during the comparison between the moment of transmitting and the moment of receiving the reflected beam part, and the speed of the vehicle is derived when the position of the vehicle is determined to be within a desired traffic lane to correspond to a defined time that is compared within a measuring window.

2. The method as claimed in claim 1, wherein said warning signal is used to activate a camera for making a record, and the measured speed and distance of the vehicle are included in the recording.

3. The method as claimed in claim 1, wherein the speed of the vehicle is determined from a difference in wavelength detected during the comparison between the reflected beam part and the transmitted wave beam.

4. The method as claimed in claim 3, wherein the vehicle is within the desired traffic lane when the detected time lag is within the measuring window defined by a lower and/or an upper threshold value(s).

5. The method as claimed in claim 1, wherein the wave beam is transmitted in pulse form.

6. The method as claimed in claim 1, wherein during the speed measurement the direction of travel of the vehicle is also determined.

7. An apparatus for measuring the speed of a vehicle comprising

means for generating and transmitting a directed wave beam,

means for receiving a part of the wave beam reflected by a vehicle,

means for comparing the reflected beam part with the transmitted beam and deriving both speed and the position of the vehicle from this comparison,

means for comparing the measured speed with a maximum allowed speed, and

means generating a warning signal when a speeding offense is determined,

wherein the position determining means derives the position of the vehicle from a measured time lag, and the speed determining means derives the speed of the vehicle when the position of the vehicle is determined to be within a desired traffic lane to correspond to a defined time that is compared within a measuring window.

8. The speed measuring apparatus as claimed in claim 7, further including a camera controlled by the speed measuring apparatus for making a recording when the speeding offense is determined, and arranged for showing the measured speed and position of the vehicle.

9. The speed measuring apparatus as claimed in claim 7, wherein the comparing means compares the wavelength of the reflected beam part with that of the transmitted beam, in order to derive the speed of the vehicle from a detected difference in wavelength.

10. The speed measuring apparatus as claimed in claim 9, wherein the comparing means compares the detected time lag with a lower and/or an upper threshold value defining the measuring window that corresponds to the desired traffic lane and ignores reflected beams which are received outside said measuring window.

11. The speed measuring apparatus as claimed in claim 9, wherein the comparing means derives the direction of travel of the vehicle from the detected difference in wavelength.

12. The speed measuring apparatus as claimed in claim 7, wherein the beam generating and transmitting means generates and transmits a wave beam in the form of a pulse.

13. The speed measuring apparatus as claimed in claim 7, wherein the beam generating and transmitting means includes an antenna provided with slots for transmitting the wave beam at an acute angle to the direction of movement of the vehicle.