Method and system for controlling traffic flow at a traffic signal system

Abstract

Method for controlling traffic flow at a traffic signal system, wherein the method comprises: - Displaying traffic signals by the traffic signal system, - Detecting vehicle occupancy on at least one monitored lane (LS1, LS2), wherein, in the event of a defined vehicle occupancy, the method further comprises: - Sending information to at least one first vehicle (V1, V2), which informs the first vehicle (V1, V2) about a type of first auxiliary light signal (LED1) to be displayed to at least one second vehicle (V3, V4, V5, V6, V7, V8; Bus1), - Displaying the first auxiliary light signal (LED1) from the first vehicle (V1, V2) to the at least one second vehicle (V3, V4, V5, V6, V7, V8), wherein the first auxiliary light signal (LED1) is to be displayed to the at least one second vehicle (Vehicle 3, Vehicle 4, Vehicle 5, Vehicle 6, Vehicle 7, Vehicle 8; Bus 1) orders a behavior, and system for controlling a traffic flow.

Description

The invention relates to a method for controlling a traffic flow at a traffic signal installation and to an installation designed for this purpose.Light signal systems (LSA) are often used to control intersections. As a primary task, these have to keep the waiting and loss times for the road users low by a skillful release time distribution.The prior art in light signal systems (LSA) is that the release times for the road users are switched either by means of fixed time control or a traffic-dependent control.Fixed time timings always switch predefined, fixed release times (green times). The fixed timing control acts completely rigidly and cannot react to changes in the traffic flow.By contrast, this is possible for the traffic-dependent control on the basis of detection technology for detecting the traffic flow. Traffic dependent controllers may respond to changes in traffic flow to some extent and adjust their enable times.The release times can be shortened or extended to a certain extent in the traffic-dependent control. In addition, additional phases with release time windows can also be switched; a phase change is also possible. It is also common to switch bus and lane enable time preemption (APNV). This is generally indicated to the APNV by means of special signal transmitters on the LSA. The possibilities for redistributing release times are nevertheless limited, since the control for the traffic conditions typically present at an intersection has been planned in advance. Also, if the demands and traffic conditions at an intersection fundamentally change, traffic dependent control cannot easily compensate for this. Examples of this are an increased traffic demand in a driving relationship due to bypass traffic which necessitates the establishment of a new signal phase, or else the requirement for a preemption for the bus.In these cases, the traffic light system must be re-scheduled and adjusted. This includes the control sequence itself in which changes such as the insertion of an additional signal phase must be programmed in. In addition, technical measures must often also be taken on the installation, such as, for example, the installation of additional signal transmitters (red-yellow-green signals) or communication units (for example, bus radio). Overall, these adaptations are cost-intensive and planning-intensive and require a longer temporal lead with structural interventions.In summary, it can therefore be stated that conventional light signal systems and their controls can react to basic changes in the traffic flow only with limited flexibility. The requirement, for example, of an additional signal phase due to bypass traffic or an APNV preemption, is generally not easily able to be mapped for a short time by the light signal system.During the adaptation work, the traffic light system must also be taken out of operation, connected with restrictions for the traffic flow. Whenever a new adjustment becomes necessary, all the operations must be repeated.DE 10 2021 120 530 A1 relates to a method for operating a motor vehicle, wherein the motor vehicle has a communication device for receiving traffic light information which is transmitted by a traffic light and relates to the traffic light switching of the traffic light, and a vehicle lamp arrangement which has at least one vehicle lamp and is assigned to the rear or to the front or to the sides of the vehicle, wherein each vehicle lamp is used to implement an operating light function which relates to the operation of the motor vehicle, wherein at least some information item of the traffic light information item and / or derivation information item which is derived therefrom and is independent of the motor vehicle is displayed to a further traffic participant by means of the vehicle lamp arrangement.DE 10 2014 226 886 A1 discloses a method for controlling the traffic flow, in which the information about the time until a traffic light is switched to another traffic light phase is used to give the driver of a vehicle a speed recommendation for driving to the traffic light.In DE 10 2012 214 164 B3, position data of a vehicle in entry roads to a traffic signal system are recorded by a computing unit. From the position data and the permissible speed interval or time window of the vehicle, parameters of a shift schedule in the light signal system are calculated.DE 10 2015 016 349 A1 discloses an apparatus for a driver assistance system for a vehicle having: a control device which is designed to determine information about a position of a controllable road sign; the control device is furthermore designed to determine information about a position of the vehicle and is furthermore designed to determine information about at least one expected passing time at which the vehicle passes the controllable road sign.DE 10 2007 056 225 A1 discloses a method for controlling a traffic flow at an intersection of a first road with a second road or at an intersection of a second road with a first road, comprising the following steps: detecting vehicles in a predetermined environment around the intersection; determining a prediction for an occupancy of a predetermined area on the first road in a predetermined direction after the intersection from positions of the detected vehicles; deriving a behavioral recommendation for a driver of a vehicle, which is located in front of the intersection in the direction of travel and wishes to enter the predetermined area, from the prediction; signaling the behavioral recommendation to the driver.DE 10 2015 215 605 A1 relates to a method for controlling at least one traffic control system of a road network, wherein data of a vehicle are received, wherein the data contain a location position of the vehicle, and wherein the data are taken into account for controlling the traffic control system of the road network.DE 10 2008 037 883 A1 discloses a traffic light installation for generating meta information on the basis of input information about the environment of the traffic light installation. The traffic light system has: a control unit for generating the meta information on the basis of the input information; a communication unit for transmitting the meta information to adjacent vehicles; wherein the meta information is designed for generating a constant traffic flow.The object of the present invention is to provide a method and a system which do not have the above-mentioned disadvantages, which in particular make it possible to avoid basic changes to a traffic signal system when the traffic situation is changed and at the same time still meet a need for adaptation.As a solution, a method and a plant according to the independent claims are proposed. Further advantageous embodiments of the invention are evident from the dependent claims and the following description.The invention relates to a method for controlling a traffic flow at a traffic signal installation, the method comprising,displaying light signals, preferably having a signal phase, by the light signal system,detecting a vehicle occupancy on at least one monitored lane, wherein the method further comprises:sending information to a first vehicle informing the first vehicle of a type of a first additional light signal to be displayed to at least one second vehicle,displaying the first additional light signal from the first vehicle for the at least one second vehicle, also referred to as guided vehicle or guided vehicle, wherein the first additional light signal arranges behavior for the at least one second vehicle, wherein the first additional light signal indicates priority over other vehicles for the at least one second vehicle.The invention achieves in its general or specific embodiments one or more of the following advantages:The method can react flexibly and briefly to basic changes in the traffic flow.The traffic signal system does not have to be re-scheduled and technically extended for this purpose. No adaptation of the LSA control logic is necessary and no technical components such as, for example, signal generators have to be retrofitted to the installation. Such cost- and time-consuming adaptations are dispensed with.The traffic signal system therefore does not have to be taken out of operation at any time; there are no restrictions on the traffic flow.The first vehicle is capable of receiving the information informing the first vehicle of a kind of a first supplementary light signal to be displayed thereby. This is referred to as a "communicative vehicle", wherein the communicative vehicle may have still further communication functionalities. The first vehicle is in particular capable of receiving information from the traffic signal system or from a control device which is part of the system according to the invention. The first vehicle preferably contains a mobile or permanently installed receiving unit, preferably a mobile or permanently installed transmitting and receiving unit.In the method, the first vehicle, and optionally also further vehicles, can be a cooperatively automated vehicle (CAV, abbreviated: Cooperative Automated Vehicles), which is discussed in more detail below. The method can advantageously use the potentials of CAVs for control interventions. Non-communicative vehicles can also be taken into account within the scope of the method, i.e. not all vehicles involved in the method need to be communicative vehicles.The at least one second vehicle may, but need not, be a communicative vehicle.A control device mentioned above may be installed at any location. It does not have to be installed in the vicinity of the traffic light system or at an intersection. The use of a central control device is also possible, which can maintain a radio connection to all communicative vehicles, in particular CAV, in a traffic network.For the first vehicle, which performs a control and signaling task, no special signals have to be installed or special phases have to be set up on the LSA side.The method of the present invention is fully compatible with existing LSA control methods. This includes all common methods, such as a classic fixed time control or a traffic-dependent control.Even in the case of the combination of the method according to the invention with a traffic-dependent control, no adaptation has to be carried out to the control logic thereof. This is because these controls always have a fixed release time window after the release start. After the expiration of this fixed release time window, additional release time can then be switched if necessary. The method according to the invention is preferably used in the area of a fixed release time window and not in the optional extension area. That is, the first auxiliary light signal is preferably displayed during the duration of the fixed enable time window. The novel method is thus completely compatible with traffic-dependent control without the control logic thereof having to be adapted.The first vehicle takes over, by displaying the first additional light signal, parts of the control and signaling task which, in the classic case of the light signal system, would arrive with its control method to be adapted and the additional signal transmitters. Changes to the traffic signal system can thus be omitted, while ensuring the functional adaptation at the intersection at the same time.In a preferred embodiment, the first vehicle is a cooperative automated vehicle (CAV for short). This is understood to mean a vehicle which is capable of communication with the light signal system and / or a mentioned control device (which is not part of the vehicle) and / or a mentioned detector.The first additional light signal can be represented by a display element, which is also referred to as an external human-machine interface (eH for short). The invention thus enables a linking of one or more CAVs, including eMI, to conventional light signal systems to form an overall system.The first vehicle may be an automated vehicle that moves in road traffic without driver intervention. In this case, the first vehicle can use externally available information, such as information from a traffic signal system, for example signal images of a traffic signal system sent by V2X communication. The first vehicle can thus, for example, optimize its approach to the traffic light system and avoid stops.In one variant of the invention, a signal can be transmitted from the vehicle to the traffic signal system. The traffic light system can react to the first vehicle, depending on which information it sends, for example speed information. The preferred features of the first vehicle may also be present in other vehicles mentioned in this specification.The light signal system preferably has a transmitting and receiving unit, also referred to as a roadside unit (RSU for short). It can send information about this, e.g. by means of data messages, and preferably also receive it. Information can preferably be sent to and / or received from: at least one vehicle, a control device and / or a detector, which are mentioned below.Information is preferably selected from the state, such as the signal image (red-yellow-green signals) currently also displayed visually, or the current signal phase. This information can in turn be received by vehicles which are designed as communicative vehicles which preferably have a transmitting and receiving unit installed in the vehicle or carry it with it in a mobile manner.Information such as the mentioned items can be sent directly from the traffic signal installation, as mentioned, to an already mentioned control device or to road users.The first vehicle can receive commands from the control device in which time period a signaling with the first additional light signal is to be carried out.The first vehicle can receive commands from the control device in which time it should stand at a specific position, preferably a specific position.The light signal system preferably remains unchanged in its signal display during the display of the first additional light signal. The light signal system preferably switches its previous release times with the existing control method and signals them with the existing signal transmitters. The first vehicle provides a first auxiliary light signal in addition to signals from the traffic light system.The additional light signal is preferably assigned a temporal signal phase. The additional light signal is preferably assigned an enable time if it is an enable signal or a non-enable time if it is a stop signal.Vehicles that are communicative vehicles may preferably send information to the traffic light system, such as current position or speed data. This results in, for example, a bidirectional communication from and with the light signal system. As a radio standard, e.g. WLAN-802 is used. 11p (V2X communication).Individual aspects of the method according to the invention are discussed in more detail below:Light signals displayed by the traffic light system instruct vehicles to behave, for example, stop or drive. Light signals are, for example, a green signal or a red signal, with or without direction indication.The traffic signal system is preferably located at an intersection, a circular traffic, a ramp or a junction.The display of light signals by the light signal system is preferably at least a display of a light signal for the at least one first vehicle and for the at least one second vehicle. The display of light signals by the light signal system is preferably a display of a light signal for the lane in which the at least one first vehicle is located and for the at least one first vehicle and for the lane in which the at least one second vehicle is located. Particularly preferably, light signals are displayed to all vehicles which are located in the region of the light signal system, particularly preferably for vehicles in all lanes which are located in the region of the light signal system.A signal phase is preferably assigned to a light signal of the light signal system, which is a time phase in which the signal is displayed. In the case of a green signal, the signal phase is also referred to as the release time window. The signal phase is preferably a permanently set signal phase, preferably a signal phase within the framework of a fixed time control. After the end of the permanently set signal phase, which is also referred to as the first signal phase, an additional signal phase can then be present if necessary, which is referred to as the second signal phase.In a particular embodiment, a light signal of the light signal system is displayed with an associated signal phase for the at least one first vehicle and for the at least one second vehicle, and the first additional light signal is displayed by the at least one first vehicle during this signal phase, preferably an above-mentioned permanently set signal phase.The at least one monitored lane is a lane in which traffic is regulated by the traffic signal system. The at least one monitored lane is preferably a lane at an intersection, a circular traffic, an approach or a merging, particularly preferably a lane which has a stop line in the traffic signal system.One, several or all lanes can be monitored, the traffic of which is regulated by the traffic signal system.The detection of a vehicle occupancy on the at least one monitored lane is preferably carried out with a detector. The detector can preferably send information, such as the vehicle occupancy or type of a vehicle in the at least one monitored lane, to the already mentioned control device. The detector may include an image recognition means, for example, to identify a type of vehicle.A possible detector is preferably selected from the following, these examples being non-limiting:an optical detector, preferably a camera,a wireless detector which can preferably detect radio waves. Specific examples are detectors capable of V2X or Car2X communication,an inductive detector, for example an inductive loop.The first vehicle can be located in any lane, specific variants are still mentioned. The first vehicle may be located on a monitored lane itself. The first vehicle is preferably located on a stop line at the traffic light system.The information informing the first vehicle of a type of a first additional light signal to be displayed to at least one second vehicle may also include information instructing the first vehicle to behave, for example, not to continue driving or stop, or to drive.The at least one second vehicle is preferably a vehicle which is located on a stop line at the traffic signal system. In the case of a plurality of second vehicles, one of these is preferably located on a stop line.The at least one second vehicle is preferably a vehicle that is located in a different lane than the first vehicle.The commanded behavior may be selected from, without limitation and by way of example: a driving permission (such as to drive the bid), a driving prohibition (such as to stop or not to start), the bid to slow or speed, or a warning signal. In addition, an allowed or offered direction of travel or a prohibited direction of travel can be added, for example, an allowed or allowed direction of travel can be added in the case of a travel permission, or a prohibited direction of travel in the case of a travel prohibition.A display element for the first additional light signal can be selected from: lamps or projectors, for example an LED light strip, an LED matrix display, a laser projector, without limitation and by way of example.The first auxiliary light signal may include one or more colors, one or more symbols, and / or one or more fonts. The first additional light signal is preferably a green signal or a red signal.The first additional light signal can have a direction indicator, it can in particular be a green signal or a red signal combined with a direction indicator.The first additional light signal is preferably arranged in an outer side of the first vehicle, particularly preferably on the front of the first vehicle.A second additional light signal, which is still mentioned, is preferably arranged in an outer side of the first vehicle, particularly preferably at the rear of the first vehicle.Specific embodiments of the method are described below. Advantages of these embodiments are explained in more detail in the exemplary embodiments.In one specific embodiment of the method, the detection of a vehicle occupancy is a detection of a number of vehicles and / or of a type of vehicle in the at least one monitored lane, the defined vehicle occupancy being an exceeding of a defined number of vehicles and / or the presence of a defined type of vehicle in the monitored lane. In this embodiment, when the vehicle occupancy is high, the traffic flow can be controlled in such a way that vehicles drain off from the monitored lane and back-jams are avoided, or defined vehicles, e.g. buses or rescue vehicles, can be given priority.In one specific embodiment of the method, the at least one second vehicle is located in the monitored lane. In this embodiment, priority can be given to the at least one second vehicle, for example, if the monitored lane is occupied high by vehicles, or conversely a secondary rank can be arranged if the lane is occupied low and priority is to be given to other lanes.In one specific embodiment of the method, the first additional light signal indicates priority to the at least one second vehicle over other vehicles that are located on a travel path in the opposite travel direction.In one embodiment of the method, the first vehicle is a oncoming vehicle for the at least one second vehicle. Preferably, the first vehicle is located on a stop line. In this embodiment, the first auxiliary light signal can be very well shown visible to the second vehicle because it is in oncoming traffic, preferably opposite at an intersection.In one embodiment of the method, the information informs the first vehicle about its priority or priority over the at least one second vehicle. In this embodiment, the first vehicle is directly informed and the vehicle or driver knows the behavior while other vehicles are arranged the behavior by the first supplementary light signal.In one embodiment of the method, the method further comprises: displaying a second additional light signal from the first vehicle to a third vehicle that is located behind the first vehicle as viewed in the direction of travel of the first vehicle, wherein the second additional light signal indicates priority or priority to the third vehicle over the at least one second vehicle. The at least one second vehicle may be referred to as a "second vehicle.". In this embodiment, vehicles can be informed of a behavior by the second additional light signal which deviates from the behavior arranged by the light signal system. In this case, the first and second supplementary light signals have a higher priority.In one embodiment of the method, the monitored lane is a turn lane and, during a turn process of a vehicle located on the turn lane, a lane is crossed in the opposite direction. In this embodiment, for example (in a right hand traffic system) traffic on a left turn lane can be derived particularly well if it is heavily occupied.In one embodiment of the method, the first additional light signal permits an obligatory deflection.In one embodiment of the method, the defined type of vehicle is a bus, a roadway, a rescue vehicle, a fire vehicle or a police vehicle. These are vehicles which can preferably be given priority by the first additional light signal.In a further aspect, the invention relates to a system for controlling a traffic flow, comprisinga light signal system configured to display light signals in a direction of travel and in a direction of opposite travel,a detector for detecting a vehicle occupancy on at least one monitored lanea control device which can receive signals from the detector and is configured to transmit information directly or indirectly to a first vehicle which is capable of receiving such information when a defined vehicle occupancy is present in the at least one monitored lane, wherein the information informs the first vehicle about a type of a first additional light signal which is to be displayed to at least one second vehicle, wherein the control device is further configured to control a display of a first additional light signal on the first vehicle for the at least one second vehicle, wherein the first additional light signal assigns a behavior to the at least one second vehicle, wherein the first additional light signal indicates priority over other vehicles to the at least one second vehicle.With regard to the design of the plant, reference can be made in full to the methods and explanations described above. In the method, explanations have already been given, for example, on the detector and the control device. The system can be designed in such a way that any method described is carried out therewith. The plant can be designed such that any object described above can be present therein. Conversely, the method may utilize any feature described in the apparatus generally or in specific embodiments.In one embodiment of the system, the control device is furthermore configured to control a display of a second additional light signal from the first vehicle to a third vehicle which is located behind the first vehicle as seen in the direction of travel of the first vehicle, wherein the second additional light signal indicates priority or priority to the third vehicle over the at least one second vehicle.The control device is preferably connected to the traffic light system in such a way that information can be transmitted from the traffic light system to the control device. Preferably, the light signal system can transmit information about displayed light signals to the control device. This can be information about light signals that have / will be displayed currently, in the past and / or in the future. Alternatively or additionally, the light signal system can receive information on time periods of displayed light signals to the control device. This can be information about time periods of light signals that have / are currently displayed, in the past and / or in the future.The connection between the control device and the traffic light system can be wired or wireless.In one embodiment of the system, at least one time from which a light signal change by the light signal system takes place is stored in the control device or can be transmitted to the control device. The light signal change is preferably a change to an enable (preferably green signal), wherein the time is then referred to as the start of the enable time. With this embodiment, even more accurate control is possible. The control device can transmit the time to one or more vehicles, in particular the first vehicle and the at least one second vehicle. The vehicle / s can adapt their driving behavior on the basis of the information obtained before reaching the traffic signal system, in particular a stop line.In one embodiment of the system, the control device is configured to transmit the time to the first vehicle during its travel.The control device is preferably connected to the detector in such a way that information can be transmitted from the detector to the control device. The detector can preferably transmit information about a vehicle occupancy in the at least one monitored lane to the control device. This can be information about a vehicle occupancy that was / will be detected currently, in the past and / or in the future. Alternatively or additionally, the detector can be information about time periods of a vehicle occupancy to the control device.The connection between the control device and the detector can be wired or wireless.The control device and the at least one first vehicle are configured such that information can be transmitted from the control device to the first vehicle, and preferably also vice versa. The connection between the controller and the first vehicle is wireless.The invention is explained in more detail below with reference to exemplary embodiments. The figures show: FIG. 1 shows an exemplary embodiment of a method according to the invention in the application of an additionally required left-turn phase; FIG. 2 shows an exemplary embodiment of a method according to the invention in the case of a preemption for a bus; FIG. 3 shows simulation results for the embodiment "left turn phase"; FIG. 4 shows simulation results for the embodiment "Busbevorrechtigung".FIG. 1 shows the exemplary embodiment of an additionally required left-turn phase: an intersection consists of the arms 1, 2, 3, 4. each entry has two lanes, of which a separate lane for left-turn drivers and a combined lane for straight drivers and right-turn drivers.In the existing control, incoming traffic streams have simultaneously an enable, i.e. the signal groups SG1 and SG3 or SG2 and SG4 always show green simultaneously. This expresses itself in the two phases P 1 and P 2.During the release time, the traffic streams from the approaches 1- 4 can travel in all three possible relations, i.e. straight, left or right.Vehicles turning left must always take care of the progress of oncoming traffic before they can turn because of this regulation. One speaks of the so-called passed left turn.Many vehicles turning left, e.g., because of bypass traffic, and many vehicles driving straight ahead or turning right from the opposite direction at the same time, may backlog the vehicles turning left. In this case, an additional left turn phase with left turn signal generators would be necessary to provide additional clearance time and to release the backlog for the left turning vehicles.This is included by an autonomous intersection control device AKS in combination with a cooperatively automated vehicle (CAV) Fzg 1 and Fzg 2. Display elements B 1, B 2, which are also referred to as eMI (external human-machine interface), are implemented for the two left-turn driving relations FR 1 and FR 2. First additional light signals LED 1, LED 2 are displayed with display elements B 1, B 2, as will be explained below.The vehicles Fzg 1 and Fzg 2, which are "first vehicles" within the meaning of the invention, are CAVs with eMI. The vehicles Fzg 1 and Fzg 2 both wish to travel straight ahead and are ideally located at the first position behind the stop line H in each case during the red phase of the signal groups SG 2 and SG 4.At the time when the signal groups SG2 and SG4 switch to green (release time start), the vehicles Fzg1 and Fzg2 receive a command from the control device AKS by radio transmission, e.g. by V2X communication or mobile radio connection:The command of the control device AKS to the vehicles Fzg 1 and Fzg 2 contains the duration for which they should remain at their current position and which signaling is to be displayed via their display elements B 1, B 2. The first additional light signals LED 1 are represented by display elements B 1, here LED light bands. For example, 15 s can be specified as the stationary duration, and for example, the change of a first additional light signal LED 1 of the LED light band B 1 from deactivated to a green color (gray color in FIG. 1 ) in the vehicle front region of the vehicles Fzg 1 and Fzg 2 can be specified as signaling.During this duration, the vehicles Fzg 1 and Fzg 2 block the back-up of vehicles behind them, which are in the same lane. This makes it possible to ensure a safe left turn for the driving relations FR 1 and FR 2 during this time period, which the vehicles Fzg 1 and Fzg 2 display to the other vehicles via their green-lighting LED light band B with the first additional light signal LED 1 in the front area.The detectors D monitor the lanes FS 1, FS 2, FS 3 and FS 4, which are left-turn lanes. Each of the tracks is assigned a detector in this example, in this case a camera in each case. In the illustrated situation phase P 2, in which SG 2 and SG 4 show green at the same time, for example, only the lanes FS 1 and FS 2 are monitored, but all lanes FS 1, FS 2, FS 3 and FS 4 can also be monitored.The left-turning vehicles Fzg 3, Fzg 4, Fzg 5, Fzg 6, Fzg 7 and Fzg 8 in the monitored lanes FS 1 and FS 2 are second vehicles within the meaning of the method according to the invention. The vehicle drivers of the vehicles turning left on the driving relations FR 1 and FR 2 recognize this situation such that the vehicles Fzg 1 and Fzg 2 are stationary and thus grant them the forward travel, signaled by the green light band as the first additional light signal LED 1. They can thus turn without danger, comparable to a green-pointing signal transmitter for left-hand turners (green arrow) installed fixedly on the LSA. FIG. 1 shows the time at which the vehicles Fzg3, Fzg4, Fzg5, Fzg6, Fzg7 and Fzg8 have already executed the left-hand turn process and have already left all or part of the monitored lanes FS 1 and FS 2. At a point in time before, before the left turn operation started, Fzg3, Fzg4, Fzg5 were in the monitored lane FS 1 and the vehicles Fzg6, Fzg7 and Fzg8 were in the monitored lane FS 2.During this period, the signal generators SG 2 and SG 4 permanently show green. In order to resolve the presumed contradiction for the vehicles Fzg 9 and Fzg 10 waiting behind Fzg 1 and Fzg 2 (green signal generators of the LSA and nevertheless stand), a signal is also emitted to the traffic behind by displaying the lighting-up of the display elements B 2, here a red LED light band, which generate a second additional light signal LED 2 in the rear region of the vehicle of Fzg 1 and Fzg 2.After the dwell time transmitted by the control device AKS has expired, the first additional light signal LED 1 and the second additional light signal LED 2 of Fzg 1 and Fzg 2 cancel out again, i.e. green and red light colors are no longer displayed. The signal groups SG 2 and SG 4 still show green, the vehicles Fzg 1 and Fzg 2 are moving and travel over the stop lines.The following vehicles Fzg 9 and Fzg 10 (and other vehicles behind) are no longer stopped by Fzg 1 and Fzg 2, and can normally travel the intersection in accordance with the signal groups SG 2 and SG 4 until they change to red.The control sequence of the light signal system proper is thus unchanged, but the CAVs Fzg 1 and Fzg 2 with the first additional light signal LED 1 and the second additional light signal LED 2 have provided for an additional, secure release phase for the vehicles turning left (Fzg 3, Fzg 4, Fzg 5, Fzg 6, Fzg 7, Fzg 8 and others not designated by reference numerals) by the implementation of the commands of the control unit AKS.In addition to this example and sequence at this intersection, one or more of the following specific embodiments can be applied for the method and the device:The control device AKS always knows the time of a release time start on a signal group. For this purpose, it does not have to be connected, but can be connected unidirectionally to the traffic signal system LSA (information flow from LSA to AKS). The release time start can be stored in the control device AKS, for example, statically from historical records. The ACS can likewise independently ascertain or train the start of the release time, for example from the optical observation of the signal groups by means of camera technology. This could also be done, for example, by the CAVs themselves, since these are generally equipped with camera technology. If the LSA sends its signal times, for example by radio communication, for example by V2X messages, the AKS could likewise receive and use them. However, a wired data transmission from the LSA to the AKS is also possible in the same way, which would mean a technical adaptation of the LSA in this individual case.If a plurality of lanes per driving relationship are present at a more complex intersection, for example a plurality of straight lanes, one Fzg1or Fzg2is included per lane. Display elements B1 and B2 are advantageous in order to block the traffic flow to the rear and to emit signaling with the display elements B1 and B2.Should a Fzg1 or Fzg2 be included. If display elements B1 and B2 at the beginning of a release time are not located directly behind the stop line as the first vehicle, this Fzg1 or Fzg2 can, even after the start of a release time, first advance as far as the stop line and only then take over the control and signaling task. Other vehicles before the Fzg 1 or Fzg 2 would initially flow off during the time elapsed since the start of the release time, and the separate left-turn phase generated by the Fzg 1 or Fzg 2 would only begin later.An additional signal phase generated by an Fzg 1 or Fzg 2 does not necessarily have to stand at the beginning of a signal phase switched by the light signal system. It may also be in the middle or at the end.In addition to a green or red LED light band B 1, B 2, another eMI for signaling is also possible. For example, a green arrow which is modeled on that of an LSA signal transmitter (left-turn arrow) or else a character and / or letter sequence such as "<<bitte turn<<".Another application is the establishment of a preemption for the bus. Ideally, a bus should strike a green signal when it arrives at an intersection and be able to pass without delay. For this purpose, special phases with additional signal generators are often set up on an LSA. The bus generally reports itself to the LSA by radio for the preemption, this switches the signal for the bus to green and holds it until the bus has passed. After passing, the bus sends a de-notification to the LSA by radio and the normal phase sequence continues. This case too can be mapped by means of the described method and the device comprising the control unit AKS and the Fzg 1, without having to carry out changes to the light signal system. The conversion is shown in FIG. 2:The intersection structure is identical to the previous implementation case with regard to the lanes, signal groups, phase sequence, turning options and priority regulations. The same reference numerals have the same meaning as in FIG. 1.A bus 1 now wishes to turn to the left on the driving relationship FR 1. For this purpose, he must take note of the signal pattern of the signal group SG 4 and the vehicle current simultaneously enabled by the signal group SG 2. In the worst case, this can initially mean waiting at a red SG 4. After the change from SG 4 to green, further waiting is possible by the priority authorisation of the oncoming traffic. In order to speed up the bus 1 and to avoid this situation, a technical adaptation of the LSA would actually be necessary for this purpose.This is now implemented by the control device AKS in combination with a CAV including eMI for the left-turn driving relation FR1.The vehicle Fzg 1 is a CAV having the display elements B 1 and B 2, which are eMI. The vehicle Fzg 1 would like to travel straight ahead and during the red phase of the signal groups SG 2 are ideally located at the first position behind the stop line H.At the time when the signal groups SG2 and SG4 switch to green (release time start), the vehicle Fzg1 receives a command from the control device AKS by radio transmission, for example by V2X communication or mobile radio connection.The command of the control device AKS to the vehicle Fzg 1 contains the duration for which it should remain at its current position and which signaling is to be displayed via its display element B 1. For example, 15 s can be preset as the dwell time, as signaling of the first additional light signal LED 1, for example by changing an LED light band B 1 (gray color in FIG. 2 ) in the vehicle front region from deactivated to a green color.During this duration of standstill, the vehicle Fzg1 blocks the rear of vehicles standing behind it, for example the vehicle Fzg10. This makes possible a reliable left turn for the driving relationship FR1 and thus the bus 1 during this time period. This indicates the vehicle Fzg 1 to the other vehicles and to the bus 1 via its green-lighting LED light band with the first additional light signal LED 1 in the front area.The bus 1 and all other vehicles on the driving relationship FR 1 can thus turn without danger, comparable to a bus signal permanently installed on the LSA and a signal transmitter for left-hand turners pointing in green (green arrow).During this period, the signal generators SG 2 and SG 4 permanently show green. The driving relations FR 2 and FR 3 may travel the intersection according to the signaling by the LSA and are not affected by Fzg 1. In order to resolve the presumed contradiction for the vehicles waiting behind Fzg 1, such as Fzg 10, a second additional light signal LED 2 can be emitted by Fzg 1, for example again using the second display element B 2, through an LED light band in the rear region of the vehicle that illuminates red.After the duration of the standstill transmitted by the control device AKS has expired, the eMI of Fzg1 is extinguished again, i.e. green or red light colors are no longer displayed. The signal group SG 2 still shows green, the vehicle Fzg 1 is moving and passes over the stop line.The following vehicles are no longer stopped by Fzg 1 and can normally travel the intersection according to the signal group SG 2 until it changes to red.The control sequence of the light signal system proper is thus unchanged, but the Fzg1, CAV with eMI, by the implementation of the command of the control unit, has ensured an additional, secure release phase for the left-turning bus.This implementation can be extended in a functional manner if the bus 1 itself is also cooperative and communication with the control device AKS takes place by radio transmission, for example by V2X communication or mobile radio connection:Since the control device AKS knows the time of the release time start at the signal group SG4, it can also transmit this to the bus 1. Depending on its current position, bus 1 can thus adapt its own speed such that it arrives at SG 4, for example, exactly at the time of the release time start. Thus, a hold can be entirely avoided. Possible back-jams at the start of release time can also be taken into account in this case, which would mean a somewhat delayed arrival time.If the bus 1 additionally continuously transmits its position to the control device AKS, this can derive from this when the bus 1 has passed the crossing and bus preemption can be aborted. The dwell time of Fzg1 can thus be dynamized and possibly shortened. Once bus preemption is completed, Fzg1 may continue earlier and restore its eMI to a neutral state.In order to subject the method according to the invention to a practical test, a simulation study was carried out with the microscopic simulation tool SUMO. For this purpose, the two application cases (left-turn phase and bus pre-emption) were modeled at an intersection in accordance with FIGS. 1 and 2 and loaded with traffic. Optimized fixed timing had to regulate the traffic supplemented by the novel method with CAVs including eMI. As a comparison reference, the same crossing was mapped once again with the exactly identical, optimized fixed time control, but now without the addition of the novel method. The modeling and simulation have the following properties:In the four node entrances, vehicles having a uniform distribution are emitted. On the combined straight and right turn lanes, 300 Fzg / hr each are on the way. In the case of the "left-turn phase", 250 Fzg / h are respectively on the left-turn lanes. In the case of application "bus preemption" (FIG. 2 ), 200 Fzg / h each are on the way on the left-turn lanes, supplemented by 15 buses / h coming from the southern crossing entrance.The signal groups each have an enable time of 35 s. In the case of applying the novel method, the CAVs, including eMI thereof, use 15 s to convert the command of the control unit into an additional phase.The ideal case with respect to CAVs is depicted including eMI. That is to say that the first vehicle which is at red behind the stop line is always a CAV including eMI and can immediately implement the commands of the control unit.The simulation time was set to 3600s.The results of the simulation study are shown in FIGS. 3 and 4. FIG. 3 illustrates how the novel method reduces the mean travel times for the road users in the "left-turn phase" application. In the reference case of optimized fixed time control, mean travel times of 198 s occur. This is because there is not sufficient left turn release time available. To solve this problem, an additional left-turn phase is necessary. This is provided by the application of the new method with CAVs including eMI, i.e. as a supplement to optimized fixed time control. As a result, the average travel time could be reduced to 105 sec. The novel method thus fulfils the intended purpose of reducing the mean waiting time for the left-hand turners.FIG. 4 illustrates how the novel method has an effect on the average travel times (left) and the average waiting times of the buses (right) in the case of "bus preemption". No appreciable differences occur in the mean travel times between the reference case of optimized fixed time control and the supplementation by the novel method with CAVs, including eMI. This illustrates the values of 123 s or 117 s. The reason for this is that the average traffic demand of the left-hand turners at 200 Fzg / h is lower than in the first scenario "left-hand turn phase". The optimized fixed time control can sufficiently operate the left-hand turners even without the addition of the novel method. However, it looks different in the medium waiting times of the buses. The reference control here causes an average waiting time of 89 s per bus. If the optimized fixed time control is now supplemented by the novel method with CAVs including eMI, the mean waiting time can be completely reduced to 0 s in this ideal case. In this ideal case, the buses always arrive at the crossing at the start of the release time. The buses no longer lose time when passing the crossing and the novel method thus fulfils the intended purpose of bus preemption.

Claims

Method for controlling a traffic flow at a traffic signal installation (LSA), wherein the method comprises, - displaying traffic signals by the traffic signal installation (LSA), - detecting a vehicle occupancy on at least one monitored lane (FS1, FS2), wherein, if a defined vehicle occupancy is present, the method further comprises: - transmitting information to at least one first vehicle (Fzg1, Fzg2) which informs the first vehicle (Fzg1, Fzg2) about a type of a first additional light signal (LED1) which informs at least one second vehicle (Fzg3, Fzg4, Fzg5, Fzg6, Fzg7, Fzg8; Bus 1) to be displayed, - displaying the first additional light signal (LED 1) from the first vehicle (Fzg 1, Fzg 2) for the at least one second vehicle (Fzg 3, Fzg 4, Fzg 5, Fzg 6, Fzg 7, Fzg 8; Bus 1), wherein the first additional light signal (LED 1) instructs the at least one second vehicle (Fzg 3, Fzg 4, Fzg 5, Fzg 6, Fzg 7, Fzg 8; Bus 1) a behavior, wherein the first additional light signal (LED 1) instructs the at least one second vehicle (Fzg 3, Fzg 4, Fzg 5, Fzg 6, Fzg 7, Fzg 8; Bus1) indicates priority over other vehicles.Method according to Claim 1, wherein the detection of a vehicle occupancy is a detection of a number of vehicles and / or of a type of vehicle in the at least one monitored lane (FS1, FS2), wherein the defined vehicle occupancy is an exceeding of a defined number of vehicles and / or the presence of a defined type of vehicle in the monitored lane (FS1, FS2).Method according to one of the preceding claims, wherein the at least one second vehicle (Fzg3, Fzg4, Fzg5, Fzg6, Fzg7, Fzg8) is located on the monitored lane (FS1, FS2).Method according to one of the preceding claims, wherein the other vehicles are located on a travel path in a direction opposite to one another.Method according to one of the preceding claims, wherein the first vehicle (Fzg1, Fzg2) is a oncoming traffic vehicle for the at least one second vehicle (Fzg3, Fzg4, Fzg5, Fzg6, Fzg7, Fzg8; Bus1).Method according to one of the preceding claims, wherein the information informs the first vehicle (Fzg1, Fzg2) about its priority or priority over the at least one second vehicle (Fzg3, Fzg4, Fzg5, Fzg6, Fzg7, Fzg8; Bus1).Method according to one of Claims 5 or 6, comprising the display of a second additional light signal (LED2) from the first vehicle (Fzg1, Fzg2) to a third vehicle (Fzg9, Fzg10) which is situated behind the first vehicle (Fzg1, Fzg2) as seen in the direction of travel of the first vehicle, wherein the second additional light signal (LED2) displays priority or priority to the third vehicle (Fzg9, Fzg10) with respect to the at least one second vehicle (Fzg3, Fzg4, Fzg5, Fzg6, Fzg7, Fzg8; Bus1).Method according to one of the preceding claims, wherein the at least one monitored lane (FS1, FS2) is a turn lane and a lane is crossed in the opposite direction during a turn process of a vehicle located on the turn lane.Method according to claim 8, wherein the first auxiliary light signal (LED1) allows an obligatory deflection.The method of any of claims 2-9, wherein the defined type of vehicle is a bus, a highway, a rescue vehicle, a fire truck, or a police vehicle.Installation for controlling a traffic flow, having - a traffic signal installation (LSA), - a detector (D) for detecting a vehicle occupancy on at least one monitored lane (FS1, FS2), - a control device (AKS) which can receive signals from the detector (D) and is configured, in the presence of a defined vehicle occupancy on the at least one monitored lane (FS1, FS2), to transmit information directly or indirectly to a first vehicle (Fzg1, Fzg2) which is capable of receiving such information, wherein the information informs the first vehicle (Fzg1, Fzg2) about a type of a first additional light signal (LED1) which is transmitted from the first vehicle (Fzg1, Fzg2), Fzg2) comprising at least one second vehicle (Fzg3, Fzg4, Fzg5, Fzg6, Fzg7, Fzg8; Bus1), wherein the control device (AKS) is further configured to control a display of a first additional light signal (LED1) on the first vehicle (Fzg1, Fzg2) for the at least one second vehicle (Fzg3, Fzg4, Fzg5, Fzg6, Fzg7, Fzg8; Bus1), wherein the first additional light signal (LED1) is associated with the at least one second vehicle (Fzg3, Fzg4, Fzg5, Fzg6, Fzg7, Fzg8; Bus 1) arranges a behavior, wherein the first additional light signal (LED 1) indicates priority over other vehicles to the at least one second vehicle (Fzg 3, Fzg 4, Fzg 5, Fzg 6, Fzg 7, Fzg 8; Bus 1).Installation for controlling a traffic flow according to Claim 11, wherein the control device (AKS) is furthermore configured to control a display of a second additional light signal (LED2) from the first vehicle (Fzg1, Fzg2) to at least one third vehicle (Fzg9, Fzg10) which is located behind the first vehicle (Fzg1, Fzg2) as seen in the direction of travel of the first vehicle (Fzg1, Fzg2), wherein the second additional light signal (LED2) displays priority or priority to the third vehicle (Fzg9, Fzg10) with respect to the at least one second vehicle (Fzg3, Fzg4, Fzg5, Fzg6, Fzg7, Fzg8; Bus1).Installation for controlling a traffic flow according to one of Claims 11 - 12, wherein at least one time from which a light signal change by the light signal installation (LSA) takes place is stored in the control device (AKS) or can be transmitted to the control device.Traffic flow control system according to Claim 13, wherein the control device (AKS) is configured to transmit the time to the first vehicle (Fzg1, Fzg2) during its travel.

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