EP0911779A2 - Method and device for monitoring road traffic over a large surface area - Google Patents

Abstract

A satellite or aircraft (3) using radar and infra red methods is used to monitor a road network (1). Information is relayed to a ground station (6) and is processed to determine traffic flow data. The movement of specific vehicles (2) can be monitored and any abnormal conditions determined.

Description

The invention relates to a method and an apparatus for large-area traffic monitoring of one of vehicles trafficable traffic network. This can be particularly act as a road network, but is possible also the traffic situation monitoring of a rail network or one Shipping network.

The published patent application WO 96/13733 describes a method for Ship traffic monitoring at sea with detection of oil spills and icebergs and possible collision risks between ships or between a ship and icebergs. This process eliminates oil spills and Icebergs on the sea surface using satellite-based SAR (Synthetic Aperture Radar) microwave sensors observed and recognized. At the same time there is a positioning device on every ship attached, which the current position of the determined ship and the corresponding position information to the satellite that transmits to the given one Time in the visibility area of this positioning device lies. The satellites then transmit the data the location and size of a detected oil spill and detected icebergs as well as those received from the ships current ship position data to an earth-fixed evaluation center. The evaluation center evaluates this data for identification the source of oil pollution and to identify potential Risk of collision between ships or between one Ship and icebergs and may issue a warning via the satellites to the affected ships.

To determine the position of vehicles, it is known under Exploitation of a satellite-based navigation system, e.g. of the GPS (Global Positioning System), and to do this install a suitable receiver in the vehicle that receives positioning signals transmitted from satellites and evaluates for vehicle position determination, see e.g. the Publication DE 196 21 917 A1.

For monitoring traffic conditions, especially in road traffic Infrastructure-based systems are frequently used today which traffic situation data with measuring devices arranged on the track side, such as induction loops etc., collected and sent to a central office are forwarded to where they are based on special algorithms Incidents are examined. This requires a considerable amount Effort for the infrastructure along the traffic route network, because the measuring devices in one for the desired accuracy of the traffic situation monitoring sufficiently small distance along each Traffic route must be attached. This is also the procedure very inflexible regarding changes in the traffic network.

In the case of a device disclosed in DE 41 28 312 A1, Infrastructure-based traffic monitoring systems are video cameras for traffic monitoring at traffic junctions or positioned at other critical points in the transport network. The pictures taken with it are from an associated one Image processing system using an appropriate one Pattern recognition method specific to the existence of the vehicle type from movements to the number of vehicles analyzed to be able to determine the type of installation for each vehicle type of the respective video camera.

Another currently practiced method is the traffic situation data manually collected by, for example, surveillance personnel with vehicles on the road network is or with helicopters known as susceptible to failure of the traffic network and overflows Reports radio or the like to a control center. This method requires confirmation of malfunction reports, after which the fault message e.g. is broadcast on the radio. The relative With this method, a long delay leads to the fact that often a announced fault no longer exists or one disturbance that has already occurred does not yet reach the road users has been announced.

More recently, traffic monitoring has been used as another method the use of specially equipped, proposed test vehicles moving in traffic, those for the determination of those encountered by the test vehicle in question local traffic flow and for the corresponding reporting Traffic flow data are set up. By using a correspondingly large number of these test vehicles, also "floating Cars ", should then from the individual local traffic flow data a realistic picture of the extensive traffic situation of the road network. This kind of random Traffic situation monitoring is, however, in principle not guarantee that the traffic is everywhere and too every point in the traffic network is precisely recorded and required also a corresponding effort for the special Equipment of the variety of test vehicles.

The invention is therefore a technical problem of providing a method and a device of the aforementioned Kind based on those with comparatively little Reliable large-area traffic situation monitoring can be effected.

The invention solves this problem by providing a Method with the features of claim 1 and a device with the features of claim 7.

In the method according to claim 1, images of the to be monitored Area in which the traffic network is located remotely through missiles, especially satellites or airplanes, added. The captured images are automated Image processing to localize traffic routes of the route network in the respective picture and for the detection of vehicles subjected to localized traffic routes. Based on recognized vehicle is then based on the current traffic situation closed.

Advantageously, no track-side is used for this method Infrastructure and no special equipment in the Vehicles needed. There are also satellites and planes with to those who take long-distance pictures of the Earth's surface can already be made known. Even automated Image processing techniques for the evaluation of such Images are already common. The image processing therefore needs only with regard to the location of the traffic routes of interest and detection of the vehicles located thereon to become what for the professional without much additional effort possible on the basis of a conventional image processing system is. The method can therefore be relatively inexpensive realize. Another advantage is the speed with which covers the traffic situation across the board, i.e. at all points in the traffic network, and at all times can be reliably determined. The process can be quick and simply expanded to new areas of the traffic network become.

In a method developed according to claim 2, the localization the traffic routes in the pictures taken below Using a conventional map matching method overlaid vector maps, which makes the interested Have traffic routes reliably determined.

In a further developed method according to claim 3 Area to be monitored Images using various imaging Radiations added. Depending on the weather conditions may be better at times with one type of radiation Images other than those obtained with a different type of radiation. From the pictures can then be the most suitable for each Evaluation can be selected, making the traffic situation monitoring largely independent of the weather conditions is possible with constant reliability.

In a method further developed according to claim 4 the traffic situation monitoring is an estimate dependent on the traffic situation the travel times between a predeterminable starting point and a predeterminable destination by the estimate based on the recognized according to the procedure and located on the traffic network Vehicles is made.

In a further developed method according to claim 5 area to be monitored repeatedly at predefinable time intervals Pictures taken. Based on the successively recorded The recognition of vehicles then becomes the creation or movement of a respective traffic disruption, i.e. it can monitor the dynamics of a particular traffic disruption become.

In a further developed method according to claim 6 the pure recognition of the place where there is a vehicle located on the traffic network, the spatial location of the detected vehicle. From abnormal vehicle positions, e.g. from the presence of one or more transverse or upturned Vehicles, then a traffic disruption e.g. in Form of a traffic accident closed.

The device according to claim 7 is suitable for performing the The method according to the invention, for which it uses one or more missiles with an image capturing system for capturing images the earth 's surface and for sending corresponding image data and has an, preferably earth-fixed, evaluation center. The evaluation center includes a suitably designed image processing system for the localization of the traffic routes of the road network and to identify the vehicles on it. Furthermore the evaluation center has the necessary conventional ones Means to based on the recognized, located on the traffic network Close vehicles to the traffic situation. On the other hand the device does not require any track-side or vehicle-side Means for traffic monitoring.

A device developed according to claim 8 includes a Travel time estimation device in such a way that it is specifically for Carrying out the method according to claim 4 is suitable.

An advantageous embodiment of the invention is in the Drawing shown and is described below.

The single figure shows a schematic block diagram of a Device for large-area traffic situation monitoring one of Vehicle traffic network.

In the figure is a fragmentary and highly schematic Part of a traffic network in the form of a road network 1 shown, which is used by vehicles 2, the Traffic situation is monitored over a large area. For this, distant pictures are taken of the surface area of the earth in which the Traffic route network 1 to be monitored is located by one or preferably made of several satellites 3. Every satellite is there for that 3 equipped with a corresponding image recording system. The images can be, for example, by means of radar or infrared radiation or other suitable magnetic Radiation. As an alternative to satellites the pictures of airplanes, especially airships, or other missiles are included. The satellites 3 are selected so that the entire area in which there are traffic routes of the traffic route network to be monitored (1), is recorded nationwide.

The data transmission paths 5 are of a conventional type Satellite 3 with an earth-fixed evaluation center 6 in data exchange connection. Send over these data transmission links 5 the satellites 3 send the data of the recorded images to the evaluation center 6. The evaluation center 6 has an automated Image processing system 7, which is designed so that it the traffic routes of the to locate the monitored route network and the localized ones Vehicles can recognize traffic routes. Such image processing systems with which from distant images Such a path localization from satellites or aircraft and high-resolution detection of comparatively small ones Objects on the surface of the earth, such as vehicles, is possible are known per se and therefore do not require any further details in the present case Explanation. In particular, can be used to localize traffic routes of the route network in the long-distance photographs a conventional one So-called "map matching method" with superimposed vector maps be applied.

The evaluation center 6 is thus available at the respective monitoring time about knowledge of the position practically everyone is currently on the monitored traffic network existing vehicles, which makes it able to get out of it in a conventional manner reliably to the current traffic situation close. The evaluation center 6 then sends corresponding Traffic situation information e.g. via radio or a radio network from those equipped with appropriate receivers Vehicles 2 received in the usual way and displayed to the driver or can be used for other purposes. For example can the transmitted traffic situation information on the vehicle side existing navigation aid for route planning or route finding support.

The traffic situation monitoring even under the most varied weather conditions to ensure, preferably at least made two sets of distant photographs, each of which Sentence covers the entire surveillance area and that on each different types of imaging radiation, such as radar radiation, Infrared radiation etc. The evaluation center 6 can then the distant images of that type of radiation that at provides the best picture quality in the current weather conditions, select for further evaluation.

The evaluation center 6 preferably uses the image processing long-distance photography not just the position of everyone, vehicle located on the traffic network, but also determined its spatial location at the relevant location, i.e. the evaluation center 6 recognizes through its image processing system 7 whether the vehicle is in its normal position along the road located or standing across the road or tilted is. The evaluation center concludes from such abnormal vehicle positions 6 to a traffic disruption blocking traffic there, such as. a traffic accident. In the figure is one such situation schematized on the basis of a particular one Traffic route section 1a symbolizes transverse vehicle 2a, behind it is a symbolically reproduced one Traffic jam formed from a variety of vehicles 2b Has.

Expediently, the distant images are monitored by the large area of the traffic network 1 in predetermined Repeated intervals. A further evaluation of the Information obtained from the image processing system 7 about the Position and location of vehicles 2 on traffic network 1 executing computer unit of the evaluation center 6 is then to do so suitably designed so that it is based on the positions and locations of the individual pictures taken in succession recognized vehicles not only the origin, but also the Movement, i.e. recognizes the dynamics of a particular traffic disruption. This enables e.g. Predictions about the development of recognized Traffic jams.

Furthermore, the evaluating computer unit of the evaluation center 6 a travel time estimation device implemented in hardware or software include with the travel times of one Starting location, e.g. a location A shown in the figure, to a predeterminable Destination, e.g. a location B shown in the figure, under Based on the determined current traffic situation estimated can be. For example, in estimating travel time from the starting location A to the destination B shown the shortest route between these two locations A, B traffic jam, symbolized by the traffic jam Vehicle 2a and the vehicles 2b behind it are taken into account become. Suitable, the traffic situation between the starting point and travel time estimation algorithms taking into account destination are known per se, so that this is not the case here needs to be received.

As from the above description of an advantageous embodiment the process of the invention makes it clear and the device according to the invention a comprehensive traffic situation monitoring for a large area of a traffic network with quick and reliable detection of traffic disruptions and all further applications, such as travel time forecasts and navigation aid procedures. Except the special design of the image processing system with regard to Localization of traffic routes and detection of those on them Vehicles is made up of common components and processes Made use of, so that the inventive method and Device according to the invention put into practice relatively simply can be. Even in the case of a very large one to be monitored A single, suitably equipped evaluation center is sufficient, with the imaging satellites or Aircraft in communication connection. Other side or subordinate evaluation centers are not absolutely necessary.

Claims (8)

Method for large-area traffic situation monitoring of a traffic route network (1) that can be driven by vehicles (2),
characterized in that Long-distance images are taken from the area to be monitored from missiles, the images taken are subjected to an image processing operation for localizing the traffic routes of the road network (1) and for recognizing vehicles (2) located thereon and the traffic situation is determined based on the vehicles detected. The method of claim 1, further
characterized in that
A map matching method with superimposed vector maps is used to localize the traffic routes. The method of claim 1 or 2, further
characterized in that
pictures of the area to be monitored are recorded by means of various imaging radiation, in particular by means of radar and infrared radiation. Method according to one of claims 1 to 3, further
characterized in that
Travel times between a predeterminable starting point (A) and a predeterminable destination (B) are estimated on the basis of the recognized vehicles (2). Method according to one of claims 1 to 4, further
characterized in that repeated images of the area to be monitored are taken at predefinable time intervals and on the basis of the vehicles (2) recognized in the successively recorded images, the occurrence or movement of a respective traffic disturbance is recognized. Method according to one of claims 1 to 5, further
characterized in that
the position of the recognized vehicles on the traffic routes is determined by the image processing process and an abnormal vehicle position is used to infer a traffic disruption, in particular a traffic accident. Device for large-area traffic situation monitoring of a traffic route network accessible by vehicles, with one or more missiles (3) which are equipped with an image recording system (4) for taking images of the part of the surface of the earth in which the traffic route network (1) is located, and an evaluation center (6) which receives image-related data from the missile (s) (3) and which uses them to assess the traffic situation,
characterized in that the evaluation center (6) contains an image processing system (7), to which the missile (s) transmit the image data of the captured images and which locates the traffic routes of the route network (1) and the vehicles (2) located on them in the captured images. recognizes and draws conclusions about the traffic situation on the basis of the vehicles recognized by the image processing system. The device of claim 7, further
characterized in that
the evaluation center (6) contains a travel time estimation device which estimates travel times between a predeterminable starting point (A) and a predefinable destination (B) on the basis of the recognized vehicles (2) on the traffic routes of the route network (1).

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