Method and apparatus for detecting vehicle wheels

• US 8,884,812 B2
• Filed: 06/05/2012
• Issued: 11/11/2014
• Est. Priority Date: 06/21/2011
• Status: Expired due to Fees

• Current Assignee: Kapsch TrafficCom AG (Datax Handelsgmbh)
• Original Assignee: Kapsch TrafficCom AG (Datax Handelsgmbh)
• Inventors: Nagy, Oliver
• Primary Examiner(s): BYTHROW, PETER M
• Application Number:
  US13/489,322
• Publication Number:
  US 20120326914A1
• Time in Patent Office: 889 Days
• Field of Search: 342 70- 72, 342/175
• US Class Current: 342/70
• CPC Class Codes: G01S 13/58 Velocity or trajectory determination systems; Sense-of-movement determination systems
• CPC Class Codes: G01S 13/91 for traffic control G01S13/93 takes precedence
• CPC Class Codes: G01S 7/415 Identification of targets based on measurements of movement associated with the target
• CPC Class Codes: G08G 1/0116 from roadside infrastructure, e.g. beacons

Abstract

Method for detecting wheels of a vehicle that is traveling on a roadway in a travel direction and the wheels of which are at least partially exposed laterally. The method including: emitting an electromagnetic measurement beam lobe with a known temporal progression of frequency from the side of the roadway onto an area of the roadway and at a slant with respect to the travel direction, receiving the measurement beam lobe reflected by a passing vehicle and recording the temporal progression, relative to the known progression, of all of its frequencies, and during the passage of a vehicle, detecting a frequency spread appearing in the recorded progression and exceeding a predetermined spread magnitude, as a wheel.

Claims

1. A method for detecting a wheel of a vehicle that is traveling on a roadway in a travel direction, the wheels of which are at least partially exposed laterally, the method comprising:

emitting, from a Doppler lidar or radar device, an electromagnetic measurement beam lobe having a known temporal progression of frequency, from the side of the roadway onto an area above the roadway and at a slant with respect to the travel direction;

receiving the measurement beam lobe reflected by a passing vehicle and recording the temporal progression, relative to the known progression, of all of its frequencies appearing at the same time as a reception frequency mixture in the device; and

during the passage of the vehicle, detecting, in an evaluation unit, a frequency spread appearing in the recorded temporal progression of the reception frequency mixture and exceeding a predetermined threshold value, as a wheel.

2. The method according to claim 1, wherein the predetermined threshold value is determined in a previous step from a frequency spread that occurs during the passage of a wheel-less part of the vehicle.

3. An apparatus for detecting a wheel of a vehicle that is traveling on a roadway in a travel direction, the wheels of which are at least partially exposed laterally, comprising:

at least one Doppler lidar or radar device that is configured to emit an electromagnetic measurement beam lobe with a known temporal progression of frequency onto a target and record the temporal progression, relative to the known progression, of all frequencies occurring at the same time from the measurement beam lobe reflected by the target, as a reception frequency mixture,

wherein the measurement beam lobe is oriented from a side of the roadway onto an area above the roadway and at a slant with respect to the travel direction, and

a downstream evaluation unit configured to detect a frequency spread appearing in the recorded temporal progression of the reception frequency mixture during the passage of the vehicle and exceeding a predetermined threshold value, as a wheel.

4. The apparatus according to claim 3 comprising a Doppler radar device, wherein the Doppler radar device is constituted by a roadside WLAN, WAVE, or DSRC radio beacon.