Method for detecting traffic infractions in a traffic light zone through rear end measurement by a radar device

• US 9,341,711 B2
• Filed: 03/14/2014
• Issued: 05/17/2016
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Jenoptik Robot GmbH (Jenoptik AG)
• Original Assignee: Jenoptik Robot GmbH (Jenoptik AG)
• Inventors: Blanke, Oliver
• Primary Examiner(s): BYTHROW, PETER M
• Application Number:
  US14/211,071
• Publication Number:
  US 20140266858A1
• Time in Patent Office: 795 Days
• Field of Search: 342/52, 342/55, 342/66, 342 70- 72, 342/109, 342/175, 340/907, 340/917, 340/936, 340/937, 701117-119
• US Class Current: 1/1
• CPC Class Codes: G01S 13/867 Combination of radar systems with cameras
• CPC Class Codes: G01S 13/91 for traffic control G01S13/93 takes precedence
• CPC Class Codes: G08G 1/0175 by photographing vehicles, e.g. when violating traffic rules

Abstract

A method for detecting a traffic violation in a traffic light zone through rear end measurement by a FMCW radar device (1). A specific position (sP₁) assigned to the front of a vehicle (3) and the radial velocity are derived from the measurement signal obtained at a first measurement time (t₁), and a first anticipated position (eP₁) for the front of the vehicle is calculated by the distance-time rule at the second measurement time (t₂) by means of the time period between the first measurement time (t₁) and the second measurement time (t₂). Through repeated calculation of an anticipated position for the front of the vehicle at further measurement times, an anticipated time when the front of the vehicle crosses a stop line (5) defining the traffic light zone is predicted iteratively with the determined vehicle velocity.

Claims

1. Method for detecting traffic infractions by vehicles in a traffic light zone defined by a stop line by rear-end measurement comprising the following steps:

setting up a FMCW radar device next to a roadway with a roadway edge and a stop line defining a traffic light zone, which FMCW radar device emits a radar beam forming a radar lobe with a radar axis,

aligning the FMCW radar device such that a monitored trafficway covered by the radar lobe completely covers the stop line and the radar axis forms an acute horizontal setup angle with the roadway edge,

determining a perpendicular distance of the stop line from the FMCW radar device,

emitting a radar beam and receiving a measurement signal in each instance at n measurement times (t_n), n≧

3, between which there is a known constant time period, which measurement signal is caused by reflection at a vehicle measured by the radar beam,

deriving a radial velocity and a plurality of radial distances and object angles from the measurement signal at a first measurement time, wherein the measurement signal at the first measurement time is caused only by reflection at a front right-hand corner of a front of the vehicle,

calculating a specific radial distance and a specific object angle from the plurality of radial distances and object angles for determining a specific position of the front of the vehicle at the first measurement time,

calculating by means of the distance-time rule a first anticipated position for the front of the vehicle at the second measurement time from the specific position determined at the first measurement time, the time period between the measurement times and the radial velocity derived at the first measurement time,

calculating an n−

1st anticipated position for the front of the vehicle in each instance by the distance-time rule at an nth measurement time in each instance from an n−

2nd anticipated position, the time period between the measurement times and the radial velocity derived at the n−

1st measurement time, where n≧

3,

calculating by the distance-time rule an anticipated time at which the front of the measured vehicle will cross the stop line from the n−

1st anticipated position determined at the nth measurement time and the radial velocity derived at the nth measurement time so that the calculated anticipated time iteratively approaches the real time at which the front of the measured vehicle actually crosses the stop line, and

triggering a camera to produce at least one evidentiary photograph when the calculated anticipated time is outside of a green-light phase of a traffic light associated with the stop line and the vehicle is located at at least one photograph line having a known distance from the stop line.

2. Method according to claim 1, wherein it is assumed for determining the anticipated positions that the vehicle moves perpendicularly toward the stop line.

3. Method according to claim 1, wherein the respective specific positions are also determined at the further measurement times and a course of travel described by the vehicle is determined therefrom, and it is assumed that the vehicle moves along the determined course of travel toward the stop line.

4. Method according to claim 1, wherein the method is carried out in an analogous manner simultaneously for determining anticipated times for more than one vehicle when more than one vehicle passes through the monitored trafficway at the same time.