APPARATUS AND METHOD FOR DETERMINING A VEHICLE FEATURE

• US 20140333469A1
• Filed: 04/30/2014
• Published: 11/13/2014
• Est. Priority Date: 05/13/2013
• Status: Active Grant

• Current Assignee: Kapsch TrafficCom AG (Datax Handelsgmbh)
• Original Assignee: Kapsch TrafficCom AG (Datax Handelsgmbh)
• Inventors: Nagy, Oliver
• Granted Patent: US 9,684,064 B2
• Time in Patent Office: Days
• US Class Current: 342/59
• CPC Class Codes: G01S 13/06 Systems determining position data of a target
• CPC Class Codes: G01S 13/50 Systems of measurement based on relative movement of target
• CPC Class Codes: G01S 13/92 for velocity measurement
• CPC Class Codes: G01S 7/41 using analysis of echo signal for target characterisation; Target signature; Target cross-section
• CPC Class Codes: G08G 1/01 Detecting movement of traffic to be counted or controlled G08G1/07 - G08G1/14 take precedence
• CPC Class Codes: G08G 1/0116 from roadside infrastructure, e.g. beacons
• CPC Class Codes: G08G 1/017 identifying vehicles G08G1/015, G08G1/054 take precedence
• CPC Class Codes: G08G 1/052 with provision for determining speed or overspeed speed measuring in general G01P

Abstract

Techniques are disclosed for determining characteristic feature(s) of a vehicle travelling on a roadway, comprising: a detector, which is directed towards the roadway and is configured to measure the movement vector of the vehicle at a current location and time, a tracking unit, connected to the detector, for calculating a target location of the vehicle at a target time on the basis of current location and time and movement vector, a first radar sensor, connected to the detector, for transmitting a radar beam directed towards the current location, receiving a reflected radar beam, and determining a frequency spectrum thereof, a second radar sensor, connected to the tracking unit, for transmitting a radar beam directed towards the target location at the target time, receiving a reflected radar beam and determining a frequency spectrum thereof, and an evaluation unit for generating characteristic feature(s) of the vehicle from the determined frequency spectra.

Claims

1. An apparatus for determining a characteristic feature of a vehicle travelling on a roadway, comprising:

a detector, which is directed towards the roadway and which is configured to measure a movement vector of the vehicle at a current location at a current time;

a tracking unit, connected to the detector, for calculating a target location of the vehicle at a target time using the current location, current time and movement vector;

a first radar sensor, connected to the detector, for transmitting a first radar beam directed towards the current location, receiving a first reflected radar beam and determining a first frequency spectrum of the first reflected radar beam;

a second radar sensor, connected to the tracking unit, for transmitting a second radar beam, directed towards the target location, at the target time, receiving a second reflected radar beam, and determining a second frequency spectrum of the second reflected radar beam; and

an evaluation unit for generating the characteristic feature of the vehicle from the determined frequency spectra, wherein the determined frequency spectra constitute the characteristic feature of the vehicle.

2. The apparatus according to claim 1, wherein a direction of the second radar beam of the second radar sensor can be controlled.

3. The apparatus according to claim 2, wherein the second radar sensor has a radar antenna with a controllable direction characteristic in form of a phase-controlled antenna array.

4. The apparatus according to claim 2, wherein the tracking unit is configured to calculate at least one further target location/time pair, wherein the second radar sensor is configured to determine at least one further frequency spectrum, and wherein the evaluation unit is configured to generate the characteristic feature from the determined frequency spectra and the determined at least one further frequency spectrum.

5. The apparatus according to claim 2, wherein the first and second radar sensors are formed by a common radar sensor, of which the direction can be controlled.

6. The apparatus according to claim 1, wherein the detector is formed by the first radar sensor, which measures a speed of the movement vector in a direction of travel of the roadway.

7. The apparatus according to claim 6, wherein the detector uses a Doppler evaluation of the first reflected radar beam for measuring the speed of the movement vector.

8. The apparatus according to claim 1, further comprising:

a database for receiving characteristic reference features of reference vehicles of known vehicle class, wherein the evaluation unit is further configured to compare the generated characteristic feature with the reference features, and, in response to determining a match, to output the vehicle class of the matching reference vehicle.

9. A system comprising at least two apparatuses according to claim 1, wherein the at least two apparatuses are mounted at a distance from one another on a gantry spanning the roadway.

10. The system of claim 9, wherein at least two of the at least two apparatuses are directed towards different lanes of the roadway.

11. A method for determining a characteristic feature of a vehicle travelling on a roadway, said method comprising:

transmitting a first radar beam, directed towards a current location, at a current time, receiving a first reflected radar beam and determining a first frequency spectrum of the first reflected radar beam, with simultaneous, prior or subsequent measurement of a movement vector of the vehicle at the current location and calculation of a target location of the vehicle at a target time using the current location, current time and movement vector;

transmitting a second radar beam, directed towards the target location, at the target time, receiving a second reflected radar beam, and determining a second frequency spectrum of the second reflected radar beam; and

generating the characteristic feature of the vehicle from the determined frequency spectra, wherein the determined frequency spectra constitute the characteristic feature of the vehicle.

12. The method according to claim 11, wherein the frequency spectra form the characteristic feature as a surface over a frequency/time plane.

13. The method according to claim 11, wherein at least one further target location/time pair is calculated, and at least one further frequency spectrum is determined, wherein the characteristic feature is generated from the determined frequency spectra and the determined at least one further frequency spectrum.

14. The method according to claim 13, wherein, for the calculation of each further target location/time pair, a further movement vector is measured.

15. The method according to claim 11, wherein a speed of the movement vector in a direction of travel of the roadway is measured using a Doppler evaluation of the first reflected radar beam.

16. The method according to claim 11, wherein the current location/time pair is determined by detecting the current time of a part of the vehicle at a predefined current location, and wherein the vehicle part is detected by comparing the frequency spectrum of the first reflected radar beam with a reference frequency spectrum determined with an empty roadway.

17. The method according to claim 11, further comprising:

classifying the vehicle, wherein the generated characteristic feature is compared with reference features of reference vehicles of known vehicle class, and, in in response to determining a match, the vehicle class of the matching reference vehicle is output.