WO2005122104A1

WO2005122104A1 - System for the photographic monitoring of traffic by means of a video camera

Info

Publication number: WO2005122104A1
Application number: PCT/DE2005/001064
Authority: WO
Inventors: Egbert Neumann; Andreas Behrens; Bernhard Dohmann
Original assignee: Robot Visual Systems Gmbh
Priority date: 2004-06-14
Filing date: 2005-06-13
Publication date: 2005-12-22
Also published as: DE102004028944A1; CH697368B1

Abstract

Disclosed is a traffic monitoring system, such as a photographic red light monitoring system (2) or a speedometer, comprising a single-picture camera which takes at least one instantaneous shot of a vehicle driving in the detection range or measuring range. The inventive traffic monitoring system is provided with a video camera (7) that continuously records the traffic situation in the detection range or measuring range and a ring memory (8) in which the generated video sequences are stored for a predetermined period of time and are fed to a computer unit (9) when called up. The called-up video sequences are assigned to the instantaneous shots and are stored in the computer unit (9),.

Description

Arrangement for photographic traffic surveillance with video camera

The invention relates to an arrangement for monitoring speed or red light violations with a single image camera, as is known as the red light monitoring system “TraffiPhot” or speed measuring devices “SpeedoPhot” and “MULTANOVA 6F” from Robot Foto & Electronic GmbH known on the market.

Hardly any other traffic offense has such a high risk potential as the red light violation. Effective and reliable red light monitoring is therefore of permanent interest as a preventive measure to raise awareness among road users. While a mature, reliable and robust, but also affordable technology and a fully automated mode of operation are important for the operator, it is of primary interest for traffic education that violations, the registration of which the driver usually detects through the perception of the flashing light, actually do are punished and punishable violations are not contestable.

The company ROBOT Foto & Electronic GmbH sells a photographic red light monitoring system (brochure "TraffiPhot III") under the brand "TraffiPhot", which enables simultaneous monitoring of several lanes with different traffic light phases and separate red start signs. The system consists of a weatherproof outer housing, which is mounted on a tubular steel pole next to the road, an inner part with a photo part (camera), control and operating part, loop detector and flashing device that can be inserted into the outer housing. The entire inner part can be removed quickly and easily without loosening the cable connections and alternately inserted into other installed outer housings. This means that only a single inner part is required to focus on the monitoring of different intersections. The system is triggered by passing an induction loop during the red phase. All vehicles that pass the induction loop during the red phase and after a pre-set delay time are registered by two photos, the first photo is to show the crossing of the stop line during the red light phase and the second photo is to prove the continuation of the journey into the intersection area and a perfect one Allow driver identification. The triggering of the first photo is triggered by driving over the induction loop, the second after a set time interval or by an additional induction loop in the intersection area, which means that the vehicles are always recorded in the most favorable shooting position for the camera, so that optimum driver identification is ensured. At the top of the image, information is exposed on the photo in two lines of data, which serve to prove the red light violation.

The red light system described fulfills the current requirements of the market for such surveillance systems, however braking or accelerating processes, temporary stopping or changing lanes of the vehicles mean that not all photos can be evaluated. In addition, no statements can be made reliably about the current traffic situation in the intersection area from the static photos. In legal disputes regarding red light violations, those affected often state that due to the traffic situation, an entry into the area where there is a risk of intersection was necessary.

Although not all red light violations can be punished with this red light monitoring system or the punishment can be challenged under certain circumstances, this system has proven itself in practice due to its many advantages. It is clear to the person skilled in the art that the disadvantage described also adheres to similar systems which take two snapshots of the vehicle in question with a signal generator other than an induction loop (e.g. a piezoelectric sensor) or with a camera other than a wet film camera (e.g. a digital camera) ,

Other solutions that help determine the state of the art are described below.

DE 195 17 536 A1 discloses a device for traffic monitoring with a video camera, which can be used, inter alia, for red light monitoring at traffic light crossings. The video camera, which is aligned with the traffic light crossing, is connected to a timer that generates continuous time information that is electronically superimposed on each frame of the video tape. Each individual picture documents the time, the traffic situation at the traffic lights and the Illuminate the respective traffic light phase. Driving in a vehicle at red is documented by the fact that the first frame of the video tape, which shows the red light lighting up, is the time base. If a vehicle then enters the intersection at red via the stop line, the single image that shows the current position of the vehicle front above the stop line delivers the second point in time. The exact time value of the red light violation results directly from the calculated time difference.

To avoid the video runtime during the yellow and green phases, the video camera is connected to a control unit of the traffic light system. This causes the video camera to be switched on at the same time as the red phase begins. After the red phase has ended, the video camera continues to run for a second and is then switched off. This gives you a video tape on which the red phases are recorded one after the other. The red phases are separated from each other by the gap of one second and the time jump from the end of one red phase to the beginning of the following red phase. The video tape is stored on a storage medium, e.g. a CD-ROM or a floppy disk is saved and electronically evaluated. Compared to red light monitoring systems of the type described in the introduction, this device has the advantage that clear evidence of a red light violation is always possible, but it requires an order of magnitude greater storage capacity and requires more effort for the evaluation of the stored information

DE 92 14 498 U1 also describes a red light monitoring system which, instead of conventional recording devices which only produce two snapshots per vehicle, provides a high-resolution camera which records television images over a period of time, the evaluation of which then takes place in a locally remote control center. Assuming the above example of 5 seconds for the recording duration and a recording sequence of 25 per second for television pictures, 125 pictures per picture must be saved and then also evaluated.

DE 198 02 81 1 proposes to significantly increase the recording sequence compared to DE 92 14 498 by using a video camera, in particular a CCD camera. DE 44 34 131 A1 shows an arrangement for detecting and locating vehicles in a predetermined zone, in particular a multi-lane roadway, the application of which can also take place in red light monitoring systems. A difference to the previously described solutions of the prior art is that in addition to the video camera with which all lanes of a lane are observed, there are other cameras in the same number as the lane has lanes. With the video camera, among other things, the vehicle coordinates are determined and the time interval up to the point in time at which the image of the vehicle registration number is to be recorded. To record the vehicle license plate, the other cameras (single image cameras) are provided, each of which illuminates an area only slightly larger than a lane width. Since the video camera works as a measuring device, very high demands are placed on it. Taking into account the minimum distance between two vehicles and the maximum vehicle speed, the minimum time between two measurements is less than 200 ms per lane. If there are only two lanes, more than 10 images must be recorded and saved. Since the recording by the respective additional camera is not sufficient for evidence, an evaluation of the video sequences would also have to take place with this solution.

GB 22 66 398 describes a vehicle observation arrangement which provides two images of a vehicle. The arrangement includes a detector that detects the presence of a vehicle and sends a signal to a first and a second video camera. The first video camera takes a telephoto image and the second video camera a wide-angle image of the vehicle. This creates a picture at the same time that clearly shows the vehicle registration number and a picture of the vehicle in its surroundings, which allows a conclusion to be drawn about its position. This document shows that the term video camera is not only used for cameras that record video sequences, i.e. image sequences, but basically for cameras that have an optoelectronic recording medium. In the abstract of JP 1 12 61 990 A, a traffic observation device with two television cameras is disclosed. The cameras are housed together with the red, yellow and green lights in the traffic light housing. One of the cameras records the intersection area and the other the lights of the traffic lights opposite. The image information from both cameras is put together in the video images displayed on a monitor.

The same requirements that are placed on the evidence that documents a red light violation are also placed on those that are supposed to prove that the speed has been exceeded.

Traffic speed measuring devices, in which only single shots are taken, also have the disadvantage, regardless of the measuring principle, as described at the beginning with the red light monitoring system "TraffiPhot", that the evidential value of single shots can be contested can possibly lead to a supposed violation not being punishable.

A traffic speed measuring device in which a single picture is taken of the appropriate vehicle is e.g. the Speedophot radar measuring device, which is in widespread use, or the MULTANOVA 6F radar measuring device from Robot Foto & Electronic GmbH.

The radar antenna, which in today's devices of this type is transmitter and receiver in one, and a camera are usually adjusted to one another and to the housing in a common housing, which can also be a measuring vehicle, so that the housing is only positioned relative to the road must become. When a vehicle enters the radar cone (measuring range) determined by the radar antenna of the radar measuring device, the permanent radar signal emitted by the radar antenna is reflected by the vehicle and experiences a frequency shift. The signal reflected back into the radar antenna is mixed with parts of the transmitted basic signal and the frequency difference is formed. which, as the so-called Doppler frequency, is proportional to the speed of the moving vehicle. To rule out erroneous measurement results, the measured value acquisition and verification of the measured values are subject to strict criteria. The recording of the vehicle is only triggered if these criteria are met, the determined speed value is assigned to the photographed vehicle and is shown in the recording.

The invention has for its object to improve a traffic monitoring system, such as a red light monitoring system or a traffic speed measuring device with a single image camera, so that to increase legal certainty the documented traffic violation can be proven beyond any doubt.

This object is achieved for an arrangement for photographic red light monitoring with the features of main claim 1 and for an arrangement for speed measurement with the features of main claim 2.

The invention will be explained in more detail using an exemplary embodiment with reference to drawings. This shows:

1 shows an example of a road intersection with a traffic light and an arrangement according to the invention positioned therefor. FIG. 2 shows a block diagram for an arrangement according to the invention

1 shows an arrangement 1 according to the invention consisting of a photographic red light monitoring system 2, which is connected in terms of signal technology to at least one signal transmitter 4 located in or on the road surface and a traffic light 5, and a video unit 3 aligned with a road intersection.

The red light monitoring system 2 does not differ in construction and in its mode of operation from conventionally known systems of the type described, for example, as the "TraffiPhot" red light monitoring system in the description of the prior art Technology were recognized. The camera (referred to below as a single image camera for better distinction) of the red light monitoring system 2, with which, in a known manner, two images of the vehicle in question are taken on wet film or a digital storage medium for each injury, detects the lanes to be monitored, here 2 lanes for incoming traffic in the direction of travel marked 6. At least the same object area is captured by the video unit 3, but as shown it is preferably larger, in order to capture the traffic situation more comprehensively. The video unit 3 consists of a video camera 7 and a ring memory 8 and, like the red light monitoring system 2, is connected to a computer unit 9 for signal and data transmission.

The operation of the arrangement will be described with reference to the block diagram shown in Fig. 2. The red light monitoring system 2 receives a signal from the traffic light 5 each time it switches to the individual signal phases. Only when a vehicle runs through a signal transmitter 4, for example an induction loop, located in the road surface during the red phase, does a signal passed from this signal transmitter 4 to the red light monitoring system 2 trigger the single image camera of the red light monitoring system 2. The single image camera is triggered a second time, if the vehicle passes another signal transmitter 4 arranged downstream in the direction of travel, or after an adjustable period of time. Relevant data such as date, time, red start time for the respective signal phase, duration of the previous signal phase (yellow phase), image serial number and code number are shown in the two recordings. The image information and data storage for each picture takes place either on a wet film or on an electronic storage medium. Regardless of the recording medium, the image information and data belonging to a recording are referred to below as a data record. Up to this point, an arrangement according to the invention does not differ from the known prior art. It is essential to the invention that a video sequence is assigned to these two data sets, which is used for detection in the event that the two data sets do not provide any unequivocal evidence of the red light violation. In order to obtain these video sequences, the video unit 3, the video camera 7 and the ring memory 8 are all present. The video camera 7 continuously records images of the current traffic situation and stores them in the electronic ring memory 8 for a predetermined time. The recording time could also be limited to the duration of the red phase and possibly part of the yellow phase. However, this would require an additional signal connection. The stored video sequences are overwritten again after the predetermined time. If, for example, the predetermined time period is 10 s, only the video sequences 10 s are stored in the ring memory 8 and can accordingly also only be called up for the past 10 s in each case.

After the second data record has been recorded (with the second recording), the red light monitoring system 2 sends a control pulse to the computer unit 9, which then requests the video sequence of the traffic situation just completed, which is stored in the ring memory 8. This video sequence is then assigned and stored in the computer unit 9 to the last two data records last recorded by the red light monitoring system 2, each of which represents a snapshot within this video sequence.

Thus, a video sequence also belongs to the two usual photos that prove the red light violation. The duration of the video sequence, given here as 10 s in the example, is advantageously set so that the traffic situation and the behavior of the traffic offender is not only recorded over the duration between the two recordings, but also immediately before the violation. As before, only the two data sets are evaluated for determination, evidence and punishment, so that effort and routine "stay the same". Only if these two data sets do not prove the red light violation beyond doubt, or the traffic offender questions the violation, will the associated video sequence evaluated.

In addition, an arrangement according to the invention has the advantage that it can in principle be created by upgrading conventional photographic red light systems with a corresponding video unit 3. There are no special requirements for the video camera 7, so that commercially available video cameras can be used here. With little technical effort, a new arrangement is created without interfering with tried and tested technology, which provides legally reliable evidence for the red light violation.

Instead of a red light monitoring system described in detail above, a traffic monitoring device according to the invention can also be a speed measuring device. The speed measuring device comprises a measuring system which emits measuring radiation, which receives radiation reflected from a vehicle located in the measuring range and determines the speed of the vehicle, as well as a camera oriented in the direction of the measuring radiation, which takes a single image of the vehicle.

The measuring system is connected to a video unit, the optical axis of which is oriented in the same direction as the camera axis, and detects at least the same object area as the camera. Like the exemplary embodiment described for a red light monitoring system, the video unit consists of a video camera and a ring memory and, like the measuring system and the camera, is connected to a computer unit for signal and data transmission. While a vehicle is in the measuring range, the video camera continuously records images of the current traffic situation and stores them in the electronic ring memory for a predetermined time. The stored video sequences are overwritten again after the predetermined time. After triggering the camera, a control pulse is sent to the computer unit, which then requests the video sequence of the just completed traffic situation stored in the ring buffer. This video sequence is then assigned and stored in the computer unit to the data records created as a result of the measurement and the individual image recording which represents the instantaneous recording within this video sequence.

Thus, the usual photo, in which data such as speed, date and time are shown, also includes a video sequence.

It will be apparent to those skilled in the art of this invention that the invention is not limited to the details of the embodiments exemplified above, but that the present invention is in other specific forms may be embodied without departing from the scope of the invention as defined by the appended claims.

Claims

claims

1 . Arrangement for photographic red light monitoring with a single image camera, which takes two snapshots of a vehicle entering the intersection during the red light phase of a traffic light, whereby a first snapshot is triggered when the vehicle passes the stop line and a second snapshot of the driver identification later in time serves, characterized in that a video unit (3) with a video camera (7) and a ring memory (8) is provided, the video camera (7) being oriented in the same direction as the single-image camera, capturing at least the same object field and at least over the duration of the red light phase in the recording state is that there is a data connection between the video camera (7) and the ring buffer (8) via which the video sequences recorded by the video camera (7) are fed to the ring buffer (8), which stores the video sequences via a predetermined Duration stores, so that in each case the video sequences can be called up, which were stored immediately before the call over the predetermined time period and a computer unit (9) is available, which gives the call signal to the ring memory (8) and the called video sequence via a signal and data connection assigns the last two snapshots and stores them permanently.

2. Arrangement for measuring the speed of a vehicle with a single image camera, which, while the vehicle is in the measuring range, creates a snapshot of the vehicle, characterized in that a video unit with a video camera and a ring buffer is present, the video camera being in the same direction as the single-image camera is aligned, at least the same object field is detected and there is at least the duration of the measurement phase in the recording state that there is a data connection between the video camera and the ring buffer, via which the video sequences recorded by the video camera are fed to the ring buffer, which stores the video sequences over a stores a predetermined period of time, so that the video sequences can be called up in each case, which were stored immediately before the call over the predetermined time period and a computer unit is present which gives the call signal to the ring memory via a signal and data connection and assigns the called video sequence to the last snapshot and saves permanently.