Method and system to obtain the traffic situation through fixed data-acquisition device

The invention relates to a method for detecting a traffic situation by stationary on Installation locations along a road network installed Data acquisition devices (detectors), the data on the state of traffic on Installation site of the respective detector according to a set measuring behavior identify and derived information set according to a Message response to a control center for traffic monitoring for further Evaluating forward.

From EP 0029201 B1 is an interactive dynamic route guidance system , in which specially equipped vehicles with a traffic computer communicate. The two-way communication takes place via beacons with a Infrared transmitting / receiving device are fitted and important at all Nodes of the road network are established. The also each having a corresponding transmitting / receiving device equipped vehicles get about these beacons from the traffic computer, among other current information about the temporally shortest routes to a desired destination point. The Main source of the traffic computer are in the traffic stream to mitbewegende, "mitschwimmende" sample vehicles. These transmit the Traffic computer in particular their travel times between major Transport nodes and waiting times at traffic signals. These Information from the traffic control center then for route guidance and used traffic management, for example by appropriate transfer traffic regulation to the to leading vehicles and an Control device are outputted on a display in the vehicle.

From generic US 5,317,311 discloses a system for traffic monitoring with fixed installed detectors known. The detectors whose sensor eg on Bridges are mounted on the lanes of a highway that measure Average speed of passing vehicles and set the number of in a unit of time passing vehicles fixed. This information means a data transmission channel (eg telephone line) to a central unit for the transmitted traffic monitoring. In the case of this system, from the Detectors reported average speeds of corresponding transmitted transmission facilities of the center to vehicles with corresponding Receiving devices are fitted and these data on a display a map section according to the locations of the respective detectors Show graphically. In this way, the road users can currently over problematic areas of the road network are informed. The measuring behavior of Detectors is usually adjusted so that a constant scanning of the Traffic situation occurs. Unlike in EP 0029201 disclosed Traffic monitoring are in the generic system, the relevant determined data for traffic monitoring not of sample vehicles and Detection stations (beacons) passed, in turn, a data forwarding to Make headquarters but there is here a data determination by the stationary installed sensors the detectors instead itself. The acquired data of the detectors however received no gaps in the traffic monitoring center. Rather sees the practical implementation of the described in US 5,317,311 System a restricted reporting behavior before the detectors. This is That only received therein information on the traffic situation detection center are when the detected by the detectors in each case over a certain period Average speed of the vehicles passing a predetermined Threshold below. Such a threshold may for example at about 50 km / h are. Thus, the load on the communication channel for the Data transmission are significantly reduced. However, this is bought so that this system only actionable intelligence on phases of the traffic can provide, in which a very high volume of traffic, so a traffic jam situation or a jam similar situation exists. Whether as an average traffic load or completely free road conditions; can under the given Restriction of reporting behavior of the detectors are not based on the detected data be decided. This would only be possible in the known system, if the Restriction on reporting behavior would be repealed, which in accordance with a sudden rise of the communication effort between the detectors and the traffic situation detection center would have to be bought.

Object of the present invention is therefore to provide a method of the generic educate kind such that with the least possible amount of communication between the fixed installed detectors and the traffic situation detection center a comprehensive, therefore was not limited to traffic jams observing the is traffic situation allows higher information gain. In addition to a System for carrying out this method are given.

This object is achieved in terms of the method with the characterizing Features of claim 1. Advantageous developments of this method result from the dependent claims 2 to 12. An inventive system for Implementing this method has the features specified in claim 13 Characteristics leaves and by the characterizing features of the dependent claims 14 and 15 advantageously it more precise.

The present invention provides that, in contrast to that of the US 5,317,311 known system is not just determined average speeds on the Road users will be passed, but that the from the primary of Detectors determined data and possibly other information by appropriate Evaluations to be transmitted to the road users Traffic information is obtained. These evaluations are made particularly in the derivative of current and / or historical traffic information and / or in the preparation of traffic forecasts and / or in the identification of Events that characterize the traffic state. In contrast to the previously known methods of traffic detection by fixed installed Detectors, the invention provides that the central detectors at least a portion of the results of the evaluation made by it of obtained from the detectors data transmitted. Each of the data acquisition Detectors involved, by presenting these results transmitted to her Measuring behavior and / or their reporting behavior in the sense of a learning system, ie new one. This means that the detectors of the of the central station to Road users who use the service headquarters in claim directed, Traffic information gain insights that enable them, their behavior to make when entering data in an optimal manner possible. This can either the measuring behavior of the sensor (eg: Should ever be measured or can be switched off temporarily? What kind of averaging over which periods to be formed) or the signaling behavior (eg: dependency the disclosure of information on the presence of certain events or proposing certain temporal distances between individual data transmissions), or both affect. Optimization under this context is to be understood that the Central at any time with the information required about the objective Traffic is supplied, whereby the cost of data transmission, so particularly the burden of communication channels is kept small as possible.

In an advantageous development of the invention provides that the headquarters of the results transmitted to the evaluation based on the installation places a Group of detectors, or even based on the location of individual detectors are selected. This selection can be carried out advantageously in the central office. In many Cases it proves to be even more convenient, the triage of results make by filtering in the respective detector itself. This can example, take place in the same manner as in currently known digital Radio receivers (RDS / TMC Radio Data System / Traffic Message Channel). A particularly expedient embodiment of the invention includes that the central station from time to time a currently valid hydrograph for traffic-related variables (eg, determines the average speed of road users) and the respective Detector to which this transition line is true, submitted to the respective to cause the detector to only detected deviations of the detected thereafter announce respective variables of the hydrograph currently valid at the headquarters. In this way, the detected measured variables can be despite temporal changes in a dramatic reduction of the information to be transmitted to the central information volume achieve. This procedure is based on the consideration that a Data transmission from a detector to the control panel is totally unnecessary, as long as the "model-like ideas", the headquarters of the current traffic situation has at the respective measuring point, do not differ significantly from reality. This can be monitored by the respective detector even when the Ideas headquarters, ie the transition line of the respective measured variable knows. For the Transmission of a transition line to a detector, a transfer of assets in be provided by points of a function curve as a result. However, it is often expedient standardized for typical developments of the traffic situation Hydrographs traffic-related variables to be determined. Therefore, the invention provides in a prior further that a plurality of such standardized hydrographs in the Detectors will be saved and the control panel to the detector a given hydrograph characterized in each case specifies that only one code is transmitted, the respective one of the stored load curves is clearly assigned. The various load curves be advantageous depending on classified weather conditions (eg dry weather, rain, ice / snow) and / or traffic-related Events (eg roadworks, occurrence of Major events, such as fairs or football matches, etc.) determined. As part of the present invention, it is advantageously also possible to replace each of the Installation predicted traffic condition at the respective detector to transmit to influence its measuring and / or reporting behavior. These Procedure is similar to the process variant in which the detectors hydrographs be defined as the basis in both cases, future expectations of Central be placed. The inventive method also offers the possibility Assumptions about the current traffic situation at an installation of the forward headquarters at the respective detector for checking to ensure that the detector in the case of significant deviations of the actual traffic condition of These assumptions can be sent to the Centre a corresponding data communication.

There are known solutions for detecting a traffic situation in which the Data acquisition devices, a locally recognizable from the traffic condition have dependent signaling behavior, that is exceeding or falling below certain thresholds to individual messages or to periodic reports can lead to the control panel. Such solutions, however, are less sensitive to local Special features (eg at road sections with inclines or curves), for Characteristics of the measured values ​​which are certain to user-related phenomena in a Distance from the data acquisition device indicate (eg Traffic disturbances upstream of the measuring point), for temporary external (eg weather-related) effects and for distinguishing features different caused, but symptomatically similar traffic situations (for example, traffic jams to structural bottlenecks and "immigrant overload congestion"). The said Characteristics and influences make themselves but by characteristic movements or jumps of the working point in the fundamental diagram relating to of speed, traffic flow (vehicles per hour) and traffic density represents (vehicles per length), noticeable. The inventive The method can be achieved in that the data acquisition means according to "Know what they have to pay" going through a learning phase, when data capture the traffic situation and forward them to the headquarters. At the beginning of Learning phase, the entire periphery of the acquired measurement data transmitted and in the Central are evaluated. The evaluations can be prepared by conventional statistical methods, or based on the training of neural networks also be carried out by fuzzy methods. By the reception of Results of this evaluation, the data acquisition devices in the situation added to recognize features in the traffic situation, the messages to be must lead Central. In this learning process, in the long term experience are collected, the data acquisition devices are, as recipients of historical traffic information. The knowledge of historical traffic information allows user-relevant detectors, leading indicators, ie for to recognize assessment of the traffic situation and significant events in the Centre forward. By contrast, knowledge of current Traffic information to help avoid the transmission of redundant measurement data. Information that a data acquisition device to that effect available will be provided, to include not only reports of traffic delays or Fault resolution, the invention also from sources outside the can originate method and be verified by the respective detector, but also centrally side created forecasts that known in advance external Influences such as weather conditions or construction plans into account, and the respective detector for the detection of deviations and their message can be used to headquarters. Users Relevant deviations are both unexpected conditions disorders as well as a missed expected Disorders. The forwarded for review to a detector traffic information does not necessarily refer to the centrally detected and completed current state limit, but may well also forecasts include for a period which is short compared with a daily curve. It is particularly expedient if the central characteristics that to a fault upstream of an installation location of a detector or a impending congestion at the installation point (leading indicators), determined and each detector transmits.

The invention will be explained in more detail with reference to FIGS. Show it:<dl tsize="6" compact="compact"><dt>Fig. 1</dt><dd>a schematic overview of the functions of The inventive method and</dd><dt>FIG. 2</dt><dd>a schematic of a system according to the invention Traffic monitoring.</dd></dl>

In the FIG. 1 shows the essential functions of the method according to the invention are for the two main components "traffic monitoring center" and "Data detectors" shown. The information flow is indicated by arrows symbolized. Since the data acquisition devices preferably at bridges that the observed roadways are excited to be fixed, they are Means designated in FIG. 1 as a bridge units. By a suitable sensor are measured data (z. B. the current speeds of passing vehicles) is determined and subjected to a pre-processing. These Pre-processing, for example, in the determination of an arithmetic Average value for a given observation period exist. It is conceivable, also to subject the captured raw data compression. The bridge unit can on user-relevant events (event detection), previously of the Traffic monitoring center that is referred to in FIG. 1 as "central" have been defined, and react like the "Sensor knowledge" (measured values ​​of a certain period to the present) with the "system of knowledge" (current Traffic information, traffic forecasts and historical information about the Form of load curves), and reports deviations from the immediate either Importance for the assessment of the current traffic conditions are or supplement or correct "system of knowledge". The exchange of information between the Office for traffic monitoring and the bridge units is via the two function blocks "communication" by the conditions of a "Communication Interface". The based in the central office, on the evaluation delivered by the bridge units information related function block data analysis is generally known as "traffic model" in the presentation referred been.

In FIG. 2 is an exemplary embodiment of a system for carrying out the Method of the invention shown in schematic form. With the Numeral 1 denotes a center for traffic monitoring, with a electronic data processing system 2, and a communication unit 3 is equipped. Over a communication channel 9, which for example in the form of Telephone lines can be designed, but preferably over a mobile network, So implemented wirelessly, the center 1 via the communication unit 3 can with a plurality of detectors 8 occur in communication. The detectors 8 are road-installed on bridges on motorway routes as and are to set up to detect the data relevant to a traffic monitoring and forwarded to the Centre. 1 To this end, the detectors 8, of which in the Fig. 2 a total of three are shown, each with a communication unit 4, a electronic data processing device 5 and a sensor 6 for Data Acquisition and equipped with an electrical power supply. 7 The Power supply unit 7 is preferably as battery-backed solar cell unit educated. preferably for the sensor 6 per se known sensors used as active or passive infrared sensors or microwave sensors are formed. Particularly advantageous is the simultaneous use of sensors with different measurement principles within the same detector 8. About Communication unit 4, the detectors 8 in a position not only the relevant Data for the traffic situation detection to the control center 1 via the communication channel 9 to transmit, but they can also be at least part of the Central 1 radiated results of the evaluation data over the communication channel 9, which is designed as a bidirectional communication channel is received. this puts the detectors 8 due to a corresponding programming Data processing device 5 in the situation, their measuring behavior and / or their Reporting behavior in the sense of a self-learning system on the basis of the Central set 1 results obtained, ie the previous setting if necessary to change. In a preferred embodiment of the invention are not specifically mentioned in the Memory unit shown the data processing unit 5 of the detectors 8 are each standardized hydrographs for traffic-related variables stored and a unique code to identify. The center 1 is thus in a position, based a transmitted code of each detector 8 a specific hydrograph pretending that without a large number of individual values ​​that the profile of the transition line characterize, to be respectively transferred. The data processing device 5 is designed to the effect of their programming as a comparator that they significant differences in the currently detected values ​​of a measured variable of a by can detect the center 1 given hydrograph. Thereby, it is possible to To optimize reporting behavior of the respective detector 8 so that only Data transfers take place over the communication channel 9 to the control center 1, if such significant deviations. During the remaining Time, such a data transmission can be prevented. In an expedient Embodiment of the invention, the detectors 8 each with a filter for Triage of results received from the central office 1 and only for a group are determined by detectors 8 a or provided. Thereby, it is possible in principle, the activities of a single detector 8 or a group installed for example along a certain stretch of a highway Detectors 8 targeted by influencing Center. 1 This means that the even the radiated detectors 8 because of their observation of the Central 1 can recognize traffic information to road users, whether the center 1 one with the current traffic situation at the installation of the detectors 8 matching impression has on the traffic situation. If this is not the case, can be immediately triggered a data transfer to the control center 1 to to effect a corresponding correction.

The method and the system for its implementation allow the extent of a realistic traffic monitoring required data transfer operations over the previously known Possibilities drastically lower. This is possible due to the surprisingly simple Measure that 1 of the employed detectors 8 of knowledge of the Central can be continuously observed by at least a part of 1 of the Central transmitted to the road users results of traffic monitoring or will also receive targeted individual information and evaluated accordingly.