EP0958563B1 - Method for determining the traffic situation, detector and control centre - Google Patents

Abstract

Optimisation of the signalling behaviour of a detector for a system for determining the traffic situation, and thus optimisation of the energy used by said detector and of the telecommunication resources expended relative to the transmission of traffic data, is made possible by a method for determining the traffic situation which uses a control centre and stationary detectors located in several points within a road network. The detectors each gather traffic data at their respective locations and transmit traffic data to the control centre according to a predefinable signalling behaviour state. Several signalling behaviour states are provided for for each detector, which states are selected at least in accordance with traffic data and define the signalling behaviour of the detector.

Description

The invention relates to a method for traffic situation detection, a detector and a headquarters.

In addition to mobile devices arranged in vehicles, the traffic situation is recorded Detectors also stationary roads with heavy traffic at certain positions arranged detectors used. These are for example on bridges, masts etc. arranged. Such stationary detectors are supplied with energy expediently by solar energy, deviating from solar elements on the detector is recorded, with a battery to enable the detector as a rule broadcasting even in low sunlight, for example at night, is provided. However, that is for sending data from the stationary detector on a control center that can be used by mobile radio etc. due to the sun's radiation in the Limited over a day; an enlargement of the solar elements to increase the maximum absorbable solar energy is the cost of larger solar elements, the space requirement and the visual conspicuity. Thus, a stationary one Do not send the detector in any short time intervals. Moreover, shortening the transmission time interval and / or the amount of data transmitted, that is Transmission power is also available due to random fluctuations standing solar energy, in particular through cloud cover or precipitation, limited. Furthermore, there are costs associated with communication via mobile radio, etc.

US-A-5,317,311 discloses a stationary detector for measuring the Speed of passing vehicles. If these vehicles for one time is less than a predetermined speed, a Message sent to a central office. The specified time may vary Traffic density can be varied. A change in this predetermined time leads however, not to change the reporting behavior, but only change one Variable of the criterion according to which a reportable event is selected. If a certain result is found according to the criterion, a message from Sent detector to the control center, but not the reporting behavior of the detector changed.

The object of the invention is therefore to optimize the use of the limited Available energy for information to a control center with a detector current relevant traffic data. This task is accomplished through the objects of the independent claims solved.

The reporting behavior which can be predetermined according to the invention enables the Detector on fluctuating requirements for different reasons Transmission of traffic data from the detector to a central office. The decision Depending on the reporting behavior of the detector, of traffic data measured by this detector in the detector or in the Headquarter done. Thus the reporting behavior to the current local Adaptable traffic situation at the detector. Furthermore, the decision on the Reporting behavior state of a detector can also be hit due to measured by one or more other detectors, from these to the control center Transmitted traffic data, data about this traffic data or commands from the control center to the detector to decide on its reporting behavior is to be transmitted; this is especially the future to be expected Traffic condition at the location of the detector to decide on the future Reporting behavior of this detector can be used.

The measured traffic data, which in the decision about the future Reporting behavior state of a detector are included the vehicle speed of a detector is particularly expedient passing vehicles because the speed of the traffic situation is relatively good correlated and good for direct decision or through a traffic model Reporting behavior state of a detector is suitable. In addition, the Decision to bring a detector into a certain state, also from the Number of detectors by this or at least one other detector within one Detect the time unit of detected vehicles because the number is also used Traffic situation and thus the requirement for the transmission of data from the detector a central office correlates. The speed, number and possibly speed variance from a vehicle passing through a detector is especially to the local one Appropriate decision in the detector to change its status.

In addition to a choice of reporting behavior, a different choice is one Detection behavior state of a detector, in particular the time interval between two recordings of the traffic situation (especially speed and Number of vehicles) by a detector.

It is also expedient in the detector and / or in the control center via the to the Decide central data to be transmitted, in particular on the Determine the length of a transmission of data from the detector to a control center Parameters.

In addition to the speeds and the number of passes by a detector Vehicles is also the history on this detector for the decision about his reporting behavior state suitable. In particular, the decision about the reporting behavior status of fluctuations, especially the variance, from on a detector detected vehicle speeds and / or the detected Number of vehicles at one or more times in the past be taken into account.

For a decision to change from a reporting behavior state to one other signaling behavior status can in particular be at least one threshold value Vehicle speeds and / or vehicle variance are defined at the Data are transmitted to the head office if the value is undershot and / or exceeded, however, at greater or lesser intervals than in the previous one Meldeverhaltszustand.

Historical traffic data is expediently stored in the detector and / or the control center stored, which in particular to define the criteria, in particular Speeds and / or speed fluctuations can be used can, based on which criteria about the state of a detector to be selected is decided. In particular, this can be a learning process to optimize the Decision on the change in the reporting behavior carried out become.

For deciding on the future reporting behavior of a detector in particular, traffic-independent parameters are also taken into account. So can the days of the week and / or weather data and / or the state of charge of the Battery of a detector in addition to pure traffic data are taken into account; she can also be taken into account when building a historical database and to determine criteria for deciding on the Reporting behavior state of a detector in the control center and / or in a detector.

A parameter evaluation is possible in the detector and / or in the control center. It is useful to evaluate local parameters such as local traffic data and other local data (local precipitation, temperature, state of charge, etc.) one detector each through this detector. The evaluation of temporal Changes to traffic data are possible in the detector; it is preferably done in the main office.

The transmission of traffic data and / or instructions from a detector A control center and / or from a control center to a detector is advantageously carried out by Mobile radio, in particular GSM, in order to make stationary independent lines possible To create detectors.

A detector according to the invention expediently has a program for Execution of the method according to one of the method claims. A preferred embodiment of the detector relates to a sensor for weather data, in particular the temperature at the detector, which determines the local decision about the Reporting behavior state of the detector optimized.

A control center for acquiring traffic data also expediently has one Program for carrying out the method according to one of the method claims on. As an alternative or in addition to decision-making processes in the detector own decision-making processes about the Status of one or more detectors. For Decisions of the head office and a detector about the future The status of the detector's response behavior is expediently a priority control vorgeseshen. Which decision has priority can vary Depend on parameters. In particular, current events at the detector can Define the priority of its decision over the decision of the head office. Furthermore, a traffic situation detected by one or more detectors, which is not yet detected on a special detector, in the control center to a Decision on the future reporting behavior status of this particular Lead detector, which is then transmitted to the detector and priority over one local decision of the detector. So the priority of decisions of the detector or the control center in particular depending on the topicality of the Acquisition of traffic data at the detector and / or the importance of acquired or calculated traffic data on the traffic situation, which for a detector of Meaning.

Fig. 1

schematisch zwei stationäre Detektoren zur Verkehrslageerfassung an einer Straße mit Fahrzeugen und eine Zentrale,

Fig. 2

schematisch als Blockschaltbild die Kommunikation zwischen einer Zentrale und einem stationären Detektor (= Erfassungseinheit) und

Fig. 3

als Petri-Netz beispielhaft Zustandsübergänge des Meldeverhaltens-Zustands eines Detektors.

Further features and advantages of the invention result from the description of an embodiment with reference to the drawing. It shows

Fig. 1

schematically two stationary detectors for traffic situation detection on a street with vehicles and a control center,

Fig. 2

schematically as a block diagram the communication between a control center and a stationary detector (= detection unit) and

Fig. 3

as a Petri network, for example, state transitions of the reporting behavior state of a detector.

FIG. 1 shows vehicles 2, 3, 4, 5 traveling on a road 1 of a traffic network, 6, 7, of which in particular their speeds when passing a Detector 8 or 9 and the number of vehicles that have a detector 8 or 9 happen within a unit of time, detected and according to the specifiable Reporting behavior status of a detector at certain time intervals or / and Formats through a mobile radio network 10 or 11 to a traffic detection center 12 be transmitted.

In addition to stationary detectors 8, 9, mobile detectors (not shown here) can also be used capture 2 to 7 traffic data in vehicles and transmit them to the control center, which they use to inform 13 about the current or future traffic situation can use.

A stationary detector 8 is in each case at a specific point in the traffic network attached stationary. It can in particular on a bridge, over a Tunnel entrance, be mounted on a mast, a hill or the like. Because stationary Detectors can be attached to various points in the transport network for which there is no suitable energy and communication supply, stationary detectors 8 are generally designed to be self-sufficient. In particular can an independent energy supply, for example through a solar element and a battery and an independent communication device, in particular Mobile radio or the like. Have.

The detector 8 for example by solar energy and / or a battery Available energy limits the transmit energy that can be emitted by detector 8. Thus, a detector cannot be in any short time intervals and / or any number Send data.

If a detector now transmits at certain fixed time intervals, be within current events, such as traffic data, which lie within a time interval Accident, etc., only delayed to a control center, which Can not provide road users with current information. Furthermore, the one Detector available energy through external influences, such as cloud cover, Rainfall etc., limited.

Therefore, the reporting behavior, especially the time interval in which a Detector reports traffic data to a central, depending on different Influences, adjusted. The decision to adapt can be made at the headquarters 12 and / or in the detector 8. For conflicting decisions by headquarters 12 and the detector 8, fixed priority rules can be provided. For example can, if a center sends a message from a detector only every five hours required, but the detector due to the lack of passing Vehicles suspected an accident in front of the detector, contrary to the decision of Central decision for immediate reporting and / or future reporting send in short time intervals. Furthermore, reporting behavior states can only be temporary, so that a relapse into a certain reporting behavior state, which also depend on factors such as day of the week, time, temperature etc. can, is provided.

Figure 2 shows schematically the communication between a center 12 and one (referred to as a detection unit) detector 8. The detector detects a Sensor system 14 traffic data at its position; this can in particular the Speed of a vehicle passing through it; furthermore a detector from directly obtained data, such as single vehicle speeds, too mean vehicle speeds in certain time intervals, the variance average or individual vehicle speeds in the same or different Time intervals, the number of vehicles in intervals and / or the change determine the number of vehicles per time interval. In addition to immediately Data obtained, such as individual vehicle speeds, may become such derived data monitored by a local agent 15. This can in particular a special subroutine in the sequence control of a detector 8 be or can also be a separate circuit or sequence control in the detector 8. For example, a local agent can control the variance of vehicle speeds, another local agent keep track of the number of vehicles per unit of time etc. On the other hand, in the present example, an "attentive state machine" monitors 16 only standard data, i.e. speeds and possibly also derived data Sizes such as speed variance, number variance etc. A local agent 15 shares the attentive state machine 16 here if something relevant happened, such as the absence of vehicles, the lowering of the per time unit 8 vehicles passing the detector to zero. In such a Case, the attentive state machine 16 is communicated via the communication 17, 18 Mobile radio etc. inform a central office 12. This can be done through the Traffic situation detection 19 and processing 20 determine that it is a relevant event, for example through a special radio broadcast (13) etc. Inform road users. The control center 12 can also receive data from approach other detection units 8. These can be special current events or routinely collected traffic data or derived quantities.

The decision at the headquarters about a change of the current one Reporting behavior state of a stationary detector 8 can be based on it transmitted traffic data and derived data as well as on the basis of others Detectors 9 transmitted traffic data and derived data and / or on the basis of other factors such as day of the week, time, precipitation, a historical Database etc. If the control center 12 decides that the Reporting behavior state of a detector 8 is to be changed, it transmits this to him Mobile radio etc. from their communication unit 18 to the communication unit 17 a detector 8, whereupon this decides whether it is in the commanded new Status of reporting behavior goes.

FIG. 3 shows a very simple example of the reporting behavior states of a detector 8, which here only has four reporting behavior states 31, 32, 33, 34.

The reporting behavior state 31 can be characterized, for example, that a message from the traffic detector 8 to a central station 12 follows every ten minutes, the message being the average speed passing by the detector 8 Vehicles in the past ten minutes, the variance in the speeds of the Vehicles which the detector 8 has detected in the last ten minutes and which Number of vehicles that passed detector 8 in the past ten minutes include.

In state 32, the detector reports the average speed of it every minute passing vehicles in the last minute, the speed variance in the first to sixth intervals of ten seconds each in the last minute and the number of vehicles in the last minute. In state 33 the Detector every five hours speed and number of vehicles in the last five hours. In state 34, the detector 8 transmits all to the control center 12 five hours the speed in the past five hours, for each of the last five Hours the variance of the speeds of the vehicles in that hour and the Number of vehicles in the past five hours.

The reporting behavior state 33 of a detector 8 is in particular at times suitable, where nothing relevant happens regularly, for example on weekdays from midnight to 5 a.m. State 31 is particularly closed Suitable times when an observation of the traffic situation is necessary, however an accident, etc. has not necessarily already occurred. The decision 41 Transitioning from state 31 to state 32 can be made, for example if a detector detects that there are currently no more vehicles on it drive past so that an accident upstream in front of the detector is suspected. In addition to a current message to the control center 12, the detector 8 can then decide independently to go to state 32. Such one Decision 41 can also be made by a central office. If again Vehicles pass the detector 8 or vehicles again with the usual The detector 8 or the control center can drive past the speed 8 decide to transition from state 32 to state 31 again (42).

The decision to change from state 31 to state 32, therefore, more often can report, for example, for a detector 9 from a center 12 and be transmitted to it when the center 12 determined by the detector 8 Traffic data etc. recorded, such as fluctuations in Vehicle speeds, fluctuations in the number of vehicles, etc.

If unusual vehicle speeds occur, Vehicle fluctuations etc. in state 33, the center and / or a detector 8 decide (43) to change from state 33 to state 31, i.e. more often report until a decision to return from state 31 to state 33 etc. is hit (44) because a certain amount of time has passed or has passed Vehicle speeds or vehicle speed variances in again move a common area.

The same can be said for transitions between states 33, 32 and 34 or be provided between 31 and 34.

The detector 8 has a sequence control with a program for execution of the inventive method, a memory for this program and for recorded traffic data, a processor for processing the stored Program, a transmitting and receiving device for transmitting Traffic data to a central office or for receiving traffic data and / or Commands to change the reporting behavior status from the control center, one Detection unit for capturing traffic data, in particular for measuring traffic speeds passing through the detector. The different Reporting behavior states can be stored in a memory in the detector and from the Processor in the detector based on a decision in the detector or one Decision to be changed at headquarters.

The detector can in particular have sensors for weather data, such as temperature, precipitation, etc. The communication between the detector and the control center is expediently carried out via a mobile radio device on the detector.
A control center 12 also has a program for performing the method according to the invention, a memory for the program and for determined and / or calculated traffic data or traffic situation data, a processor for executing the program, a transceiver for receiving traffic data from a detector and possibly Information about the current reporting behavior status of the detector and for sending traffic data and / or commands for changing the reporting behavior status to a detector. A control center expediently communicates with a plurality of detectors 8, 9 and possibly also with mobile detectors in vehicles 2 to 7.

In addition to the status of a detector 8, the Measurement behavior state of the detector can be selected. This can also be from the detector and / or the central office can be determined. In particular, the frequency of Measurements, the type of measurements, the accuracy of measurements etc. become. In the case of energy-intensive measurements in particular, their frequency can be reduced to be changed. The measurement behavior state can be based on that of the detector or Traffic situation determined by the control center at the detector or at other points in the Transport network can be selected. Furthermore, other data, such as the state of charge the battery of a detector, the current incoming solar energy, the temperature, Precipitation etc. for the decision about the state of measurement behavior be taken into account.

Claims (20)

1. Method of recording traffic situations, with a control centre and stationary detectors at a number of locations in a traffic network, each of the detectors recording traffic data at its location and transmitting traffic data to the control centre in dependence on a predeterminable report function status, a detector having several report function statuses, which are selected at least in dependence on traffic data and which define the report function of the detector.
2. Method as in Claim 1,
   characterised in that
   a decision is made on the report function status of a detector in dependence on traffic data measured by that detector.
3. Method as in one of the preceding Claims,
   characterised in that
   the decision on the report function status of a detector is made in dependence on traffic data measured and transmitted to the control centre by one or more detectors, data on this traffic data, or commands from the control centre, being transmitted to the former detector.
4. Method as in one of the preceding Claims,
   characterised in that
   the measured traffic data include the vehicle speed of the vehicles passing by a detector.
5. Method for recording traffic situations as in one of the preceding Claims,
   characterised in that
   the decision to put a detector on to a specific status depends on the number of vehicles detected, within a unit of time, at this detector and/or at at least one other detector.
6. Method as in one of the preceding Claims,
   characterised in that
   the decision in favour of a specific report function status includes the adjustment of the time interval between each two reports from the detector to the control centre.
7. Method as in one of the preceding Claims,
   characterised in that
   the decision to put a detector on to a specific report function status and/or record function status is made on the basis of the variance of vehicle speeds of vehicles passing by a detector.
8. Method as in one of the preceding Claims,
   characterised in that,
   where data fall below a threshold value for vehicle speeds and/or vehicle speed variance, they are transmitted to the control centre regularly at longer or shorter intervals.
9. Method as in one of the preceding Claims,
   characterised in that
   historical traffic data - particularly data on vehicle speeds and/or the number of vehicles and/or vehicle speed variances at certain times of day and/or days of the week - are stored in memory.
10. Method as in Claim 9,
    characterised in that,
    on the basis of the historical traffic data, the criteria are defined - particularly speed threshold values and/or speed variance threshold values and/or the number of vehicles per unit of time - on the basis of which criteria a decision is made on the status to be selected for a detector.
11. Method as in Claim 9 or 10,
    characterised in that
    traffic data are stored for specific days of the week and/or times of day.
12. Method as in one of Claims 9 to 11,
    characterised in that
    weather data are taken into consideration, particularly data on temperatures and/or humidity and/or precipitation and/or insolation.
13. Method as in one of the preceding Claims,
    characterised in that
    the charge condition of the battery of a detector is taken into consideration.
14. Method as in one of the preceding Claims,
    characterised in that
    the evaluation of local traffic data and other data at a detector is carried out in each case by that detector.
15. Method as in one of the preceding Claims,
    characterised in that
    the evaluation of time-related changes in data, particularly traffic data, is carried out by the control centre.
16. Method as in one of the preceding Claims,
    characterised in that
    the transmission of data, particularly traffic data, and/or of instructions between a detector and the control centre, is carried out by mobile radio communication.
17. Detector for recording traffic data, particularly the speeds of the vehicles with which it is concerned,
    with a program for implementing the method as in one of the preceding Claims,
    with a memory for the program,
    with a processor to process the program,
    with a transmitter / receiver unit for the transmission of traffic data and/or of instructions between the detector and a control centre,
    with a detector unit for recording traffic data, particularly vehicle speeds,
    there being a number of statuses for the report function of the detector to the control centre, these being selected on the basis of traffic data.
18. Detector as in Claim 17,
    characterised in that
    there are measuring probes at the detector for weather data, particularly temperatures, precipitation and/or insolation.
19. Detector as in Claim 17 or 18,
    characterised in that
    there is a mobile radio device for the transmission of data.
20. Detector as in one of Claims 17 to 19,
    characterised in that
    it has a solar element and a battery.

Images