Method and system for controlling a traffic signal system

Abstract

Method for controlling a traffic signal system (TSS) by means of at least one detector (D) and a control unit (S), wherein the control unit (S) controls the phases of the traffic signal system (TSS) based on the signals of the detector (D), wherein the traffic signal system has at least one red and one green phase, wherein the detector (D) in a first direction of travel (F1) detects the presence or absence of a first vehicle (1) and a direction of travel request of the first vehicle (1), and the control unit (S) controls the red phase and the green phase for the first vehicle (1) depending on the direction of travel desired by the first vehicle (1) when the first vehicle (1) is present, and system for controlling a traffic light signal system (LSA).

Description

[0001] The invention relates to a method and a system for controlling a traffic light system.

[0002] Signal systems such as traffic lights are used to control the flow of traffic, for example, vehicles on a road. Traffic flow is controlled by controlling the signal system's phases. For example, the switching time or the duration of a red, yellow, and / or green phase can be controlled.

[0003] The methods for controlling traffic lights can be divided into three generations. The first generation is the so-called fixed-time control system. In this case, the traffic light system is controlled according to a predetermined schedule, according to which the various phases are processed. These fixed-time control systems are very robust but not flexible. In practice, therefore, several schedules are usually maintained for a traffic light system. These schedules are adapted, for example, to different traffic situations, with the traffic situations typically being based on the time of day.

[0004] Second-generation methods are so-called traffic-adaptive or dynamic control of traffic signals. Dynamic methods are significantly superior to fixed-time control in terms of their efficiency with regard to the so-called loss or waiting time of vehicles approaching the traffic signal. Loss time refers to the time a vehicle loses at a traffic signal compared to an ideal case, where the vehicle can ideally pass the signal without reducing speed. Dynamic methods are usually based on measured variables that are recorded by local detectors, e.g. via an induction loop, in a traffic signal. A widespread method for the dynamic control of traffic signals is so-called time gap control. This decides, based on a few measured variables that are as easy to collect as possible, whether a current phase of the traffic signal should be extended or whether a new phase should be switched.The measured variable is the current time gap, where the current time gap is the time that has elapsed since a vehicle last passed a vehicle detector. If the time gap or the elapsed time is greater than a critical time gap, the currently running phase can be aborted and the traffic light system switches to the next phase. In this way, the green phase, for example, can be controlled relatively easily based on the current traffic situation. In addition, the occupancy of a local detector in the traffic light system can also be evaluated, with the time that vehicles have been above the local detector being evaluated. In this way, the traffic light system is controlled based on the time gap and other data on vehicle occupancy in the approach to the traffic light system. A method of this type is described, for example, in DE 10 2014 218 848 A1.

[0005] Known detectors, as mentioned above, are used for lanes with clearly defined turning relationships, i.e., lanes where it is defined whether they are, for example, a left-turn lane, a straight-ahead lane, or a right-turn lane. However, there are often mixed lanes, such as straight-ahead / right, straight-ahead / left, and straight-ahead / right / left, where clear turning information cannot be derived from the mere detection of the vehicle with known detectors, such as induction loops. Therefore, controlling the appropriate phase of a signal system is not possible.

[0006] The invention is based on the technical problem of creating a method for controlling a traffic light system, with which the control of a phase of a traffic light system is possible even in mixed lanes depending on a desired direction of travel.

[0007] The solution to the technical problem is provided by a method and a system according to the independent claims. Further advantageous embodiments of the invention emerge from the subclaims and this description.

[0008] The invention relates to a method for controlling a traffic light system by means of at least one detector and a control unit, wherein the control unit controls the phases of the traffic light system based on the signals from the detector, wherein the traffic light system has at least one red and one green phase, wherein the detector detects the presence or absence of a first vehicle and a direction of travel desired by the first vehicle in a first direction of travel, and the control unit, when the first vehicle is present, controls a red phase and / or a green phase for the first vehicle depending on the direction of travel desired by the first vehicle.

[0009] The basic idea of ​​the invention is that not only the presence / absence of a vehicle is detected, but also the desired direction of travel of this vehicle, and the signal is controlled based on this desired direction. The method is particularly suitable for mixed lanes where straight ahead and turning are permitted, such as straight ahead / right, straight ahead / left, straight ahead / right / left. Preferably, straight ahead and turning at least to the left are permitted in a mixed lane. The first vehicle is preferably in a mixed lane.

[0010] In one embodiment of the invention, the detector detects the presence or absence of at least one second vehicle in a second direction of travel, which is opposite to the first direction of travel, and the control unit, in the presence of the first vehicle, controls the red phase and / or the green phase for the first vehicle also depending on the presence of the second vehicle.

[0011] Depending on oncoming traffic, represented by the second vehicle, a decision can be made in this embodiment as to whether the traffic light system shows red (i.e. red light signal) or green (i.e. green light signal) to the first vehicle. If there is no second vehicle present, for example, the first vehicle could be shown green. If there is a second vehicle present, a decision can be made as to whether red or green is displayed depending on the direction of travel of the first vehicle. If the first vehicle wishes to travel straight ahead, the first vehicle could be shown green, for example. If the first vehicle wishes to turn left, the first vehicle could be shown red until the second vehicle has moved away. These are only specific, non-limiting examples intended to illustrate the general principle of the invention.

[0012] The first vehicle is preferably in a mixed lane. This mixed lane is different from the mixed lane in which the first vehicle is preferably located.

[0013] The detector is preferably designed to detect the vehicle's desired direction of travel regardless of its position. This makes it possible to detect a vehicle's desired direction of travel that is not predetermined or implied by the selection of a lane (e.g., a left-turn lane). The detector preferably detects the desired direction of travel of a vehicle on one or more mixed lanes.

[0014] The detector is preferably designed so that it can detect a vehicle's desired direction of travel at a specific position, for example, in front of a stop line. Particularly preferably, the detector can detect different desired directions of travel from different vehicles that are not in this position at the same time.

[0015] The detector is preferably configured to detect the presence and desired direction of travel of the first and preferably further vehicles. The detector is preferably configured to detect a position of the first and preferably further vehicles. One or more detectors may be present.

[0016] In one embodiment of the invention, the detector can detect a signal emitted by a vehicle, which is preferably a light signal emitted by a vehicle or a radio signal emitted by a vehicle. The signal emitted by the vehicle contains, signals, or encodes information about the vehicle's desired direction of travel. In a special variant, the detector can detect the desired direction of travel by detecting a vehicle's turn signal.

[0017] A possible detector for detecting a presence and direction of travel is selected from the following, or a combination thereof, whereby these examples are not limiting: - an optical detector, preferably a camera - a wireless detector, preferably capable of detecting radio waves. Specific examples include detectors capable of V2X or Car2X communication. - a detector that can detect signals from a communicative vehicle, for example a cooperative automated vehicle (CAV). Cooperative Automated Vehicles)

[0018] In one embodiment, the detector comprises means for image recognition.

[0019] The detector is preferably not an inductive detector, in particular not an induction loop. The detector is preferably not a light barrier.

[0020] When detecting the presence or absence of a vehicle, it is preferably detected whether the vehicle is located at, in front of, or next to a traffic light. It is preferably detected whether the vehicle is located at a stop line, which is preferably associated with the traffic light.

[0021] In one embodiment of the invention, the detector also detects a desired direction of travel of the second vehicle, and if the first vehicle is present, the control unit also controls the red phase and / or the green phase for the first vehicle depending on the desired direction of travel of the second vehicle. This enables even more precise control of traffic flow because it is possible to distinguish on a case-by-case basis whether a red phase and / or the green phase is appropriate, or which type of green phase is appropriate. For example, if the second vehicle's desired direction is to drive straight ahead and the first vehicle's desired direction is to turn left, the control unit can select a conditional green phase, as explained below.

[0022] In one embodiment of the invention, the direction of travel request of the first vehicle is a turning request, in which, in the case of turning, the lane (FG) of oncoming traffic is crossed.

[0023] In one embodiment of the invention, the direction of travel desired by the second vehicle, if present, is a turn request that, in the case of turning, crosses the lane of oncoming traffic. For example, the first vehicle may have a turn request and the second vehicle is oncoming traffic, or a turn request may be a left turn request in the case of generally right-hand traffic, or a right turn request in the case of generally left-hand traffic.

[0024] In one embodiment of the invention, a green phase is switched for the first vehicle if (i) no second vehicle is detected and / or (ii) a green phase is switched for the first vehicle if a second vehicle is detected that has the same desired direction of travel as the first vehicle. An identical desired direction of travel means an identical desired direction of travel from the perspective of the respective driver. In case (i), for example, there is no risk of collision with a second vehicle because it is not present, and an unconditional green phase can preferably be switched (green with an arrow pointing in the direction of turn).In case (ii), for example, the first and second vehicles intend to go straight ahead and there is no risk of collision, or the first and second vehicles intend to turn right and there is no risk of collision, or the first and second vehicles intend to turn left and there is no risk of collision due to tangential lane guidance with non-crossing lanes.

[0025] In a variant of the previous embodiment, the green phase signals an unconditional turn. An unconditional turn means a turn without having to consider oncoming traffic; in particular, there is no need to yield to oncoming traffic. This can advantageously be the case if there is no risk of collision due to the travel paths of the first and second vehicles.

[0026] In one embodiment, the first vehicle is in a lane that allows both straight-ahead travel and turning. As mentioned, the method is particularly advantageous for mixed lanes. If a second vehicle is present, it can also be in a lane that allows both straight-ahead travel and turning.

[0027] In one embodiment, the detector detects a number of third vehicles positioned behind the first vehicle in the first direction of travel, and the control unit also controls the red phase and / or the green phase for the first vehicle depending on the number of third vehicles. In this embodiment, the control unit preferably also controls the red phase and / or the green phase for one or more of the third vehicles mentioned. This embodiment is particularly advantageous when a heavily congested lane needs to be cleared.

[0028] In one embodiment, the detector detects a number of vehicles traveling in a second direction opposite to the first direction, and the control unit also controls the red phase and / or the green phase for the first vehicle depending on the number of vehicles traveling in the second direction. In this embodiment, for example, if there is a larger number of vehicles traveling in the second direction, for example, if a queue of vehicles has formed in the second direction, a red phase is displayed for the first vehicle, and a green phase is displayed for the vehicles traveling in the second direction to break up the queue.

[0029] In one embodiment, the detector detects a number of vehicles in the first direction of travel, the first vehicle, if present, being one of these vehicles in the first direction of travel, and the detector detects a number of vehicles in a second direction of travel which is opposite to the first direction of travel, and the control unit controls the red phase and / or the green phase for the first vehicle, and preferably for vehicles behind the first vehicle in the first direction of travel (for example one or more third vehicles), also depending on a difference between the number of vehicles in the first direction of travel and the number of vehicles in the second direction of travel. In this embodiment, which can be combined particularly well with one or both of the two preceding embodiments, a decision can be made, for example based on the aforementioned difference between the number of vehicles, as to whether the vehicles in the first direction of travel are given priority over the vehicles in the second direction of travel, or vice versa. If the number of vehicles in the first direction of travel is, for example, higher, preferably higher by a minimum number, than the number of vehicles in the second direction of travel, the vehicles in the first direction of travel can be given priority, and vice versa. The difference between the number of vehicles in the first direction of travel and the number of vehicles in the second direction of travel is preferably at least 1, more preferably at least 2, even more preferably at least 4.

[0030] In one embodiment, the control unit controls a conditional or an unconditional green phase during the green phase. In other words, the control unit controls whether this is a conditional or an unconditional green phase. A conditional green phase is also referred to as a "conditionally compatible" green phase and is characterized by the fact that, despite the basic permission to proceed, other road users must still be given priority, in particular oncoming traffic whose lane is crossed. With an unconditional green phase, no other road user needs to be given priority, for example, oncoming traffic. This enables even more precise control of traffic flow because it is possible to distinguish on a case-by-case basis which type of green phase is appropriate. For example, if there is no second vehicle present, the control unit can select an unconditional green phase; if there is one, a conditional green phase.

[0031] In a further aspect, the invention relates to a system for controlling a traffic signal system, comprising a control unit and at least one detector, wherein the control device is designed to generate control signals for a traffic light system by means of signals from the detector, where the detector is designed to detect the presence of a first vehicle and a desired direction of travel of the first vehicle in a first direction of travel, and the control unit is designed in such a way that, when the first vehicle is present, it controls a red phase and / or a green phase for the first vehicle depending on the direction of travel desired by the first vehicle.

[0032] With regard to the design of the system, reference can be made in full to the previously described methods and embodiments. The system can be designed such that any described method can be carried out therewith, including according to any specific embodiment of the method, individually or in combination. The system can be designed such that any previously described item can be present or used therein. Conversely, any feature described for the system can be used in the method.

[0033] The invention is explained in more detail below using a preferred embodiment. The figures show: Fig. 1 a schematic representation of a traffic situation; Fig. 2 the explanation of a process variant according to the invention.

[0034] The Fig. Figure 1 shows a road intersection with lanes FS and the exemplary directions of travel F1 and F2. The lanes FS allow driving straight ahead or turning left at the intersection, as indicated by arrows on the lanes FS in the area of ​​the traffic lights, and also allow turning right (not shown here as an arrow). The lanes FS are therefore mixed lanes.

[0035] At the intersection, the traffic signal system LSA with the individual traffic lights LS1, LS2, LS3, LS4 is installed.

[0036] Furthermore, there is a central control unit S and four detectors D, one for each lane FS. The control unit S is connected to all detectors D via cable or radio (cable connection not shown). The control unit S controls the signal phases of the traffic light system LSA at the individual traffic lights LS1, LS2, LS3, and LS4.

[0037] The first vehicle, 1, is in lane FS in the direction of travel F1, and the second vehicle, 2, is in the opposite lane FS in the direction of travel F2. The first vehicle, 1, and the second vehicle, 2, are each at a stop line (not shown). For example, both vehicles are currently experiencing a red traffic light, meaning the traffic light system (LSA) is in red phase for them.

[0038] Behind the first vehicle 1 is the third vehicle 3, traveling in the same direction F1 as the first vehicle 1. The first vehicle 1 and the third vehicle 3 wish to turn left, coming from south to west, indicated by turn signals B. The second vehicle 2 wishes to travel straight ahead, from north to south in the direction F2. Reference symbol FG denotes the lane FS of oncoming traffic, in this case the second vehicle 2, which corresponds to the north-south lane FS.

[0039] Based on this situation, an exemplary process sequence according to the invention is shown on the basis of the Fig. 2 described: By using detector D in the southern access road, where the first vehicle 1 and the third vehicle 3 are located, it is possible to distinguish whether vehicles in the "left turn" (from south to west) driving pattern are present, and how many such vehicles are present. In this case, these are the first vehicle 1 and the third vehicle 3, both coming from the south and wanting to turn left to west. In this case, phase 3 can be specifically requested to serve and clear a queue from the south, here consisting of the first vehicle 1 and the third vehicle 3 (and preferably other vehicles). Phase 3 allows an unconditional left turn for the first vehicle 1 and the third vehicle 3 without regard to oncoming traffic, i.e. without regard for the second vehicle 2, which does not receive a green signal.Since the queue is coming from the south, the vehicles in this queue are given priority over the second vehicle 2 to reduce the queue. There may be additional (third) vehicles behind the third vehicle 3, but they are not shown.

[0040] With a conventional traffic light system on mixed lanes, such a procedure cannot be implemented and, depending on the situation, longer waiting times and delays for road users, in this case vehicles 1 and 3, occur.

[0041] Phase 3 is preferably switched when the queue has reached a defined length and preferably there is still a minimum difference in vehicles between a queue coming from the south and a queue coming from the north, with the queue coming from the south being longer by the minimum difference, which is, for example, at least 4 vehicles.

[0042] However, if there are no left-turning vehicles in the direction of travel F1, or only the same number as in the direction of travel F2 (for example, only the first vehicle 1 and the second vehicle 2 are present, but not the third vehicle 3), phase 1 can be activated instead, which also serves traffic from the north and allows the second vehicle 2 to proceed. Phase 1 allows a conditional left turn (also referred to as a conditionally compatible left turn) for the first vehicle 1, taking oncoming traffic into account. Phase 1 also allows a conditional left turn for the second vehicle 2, if desired (in Fig. 1 (the second vehicle did not indicate left). The conditional left turn is indicated by a dashed arrow.

[0043] Phase 2 allows unconditional left turns for vehicles in the direction of travel F2 without considering oncoming traffic. Phase 2 can be activated if a mirror-image situation arises. Fig. 1 is present, for example, there are several left-turning vehicles on lane FS in the direction of travel F2 from north to south and no or fewer vehicles are present in the direction of travel F1 on lane FS from south to north.

[0044] Phase 4 corresponds to the signaling of Phase 1, except that in this case, the west-to-east and east-to-west lanes are affected. Phases analogous to Phases 2 and 3 can, of course, also be applied to east-to-west and west-to-east traffic.

[0045] The detector D can be configured to detect not only the turning request of vehicles in the direction of travel F1 but also the number of vehicles in order to determine the occupancy of the lane FS from south to north and to switch to phase 3 when a defined number of vehicles is reached.

[0046] The Fig. 1 and Fig. The method described in Section 2 is merely exemplary and does not limit the general principle of the method. Further methods can be derived from the claims and are covered by their scope of protection. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2014 218 848 A1

[0004]

Claims

[1] Method for controlling a traffic light system (LSA) by means of at least one detector (D) and a control unit (S), wherein the control unit (S) controls the phases of the traffic light system (LSA) based on the signals of the detector (D), wherein the traffic light system has at least one red and one green phase, characterized by that the detector (D) detects the presence or absence of a first vehicle (1) and a desired direction of travel of the first vehicle (1) in a first direction of travel (F1), and the control unit (S) controls a red phase and / or a green phase for the first vehicle (1) in the presence of the first vehicle (1) depending on the desired direction of travel of the first vehicle (1). [2] Method according to claim 1, characterized bythat the detector detects the presence or absence of at least one second vehicle (2) in a second direction of travel (F2) which is opposite to the first direction of travel, and the control unit (S), in the presence of the first vehicle (1), also controls the red phase and / or the green phase for the first vehicle (1) depending on the presence of the second vehicle (2). [3] Method according to claim 2, characterized by that the detector (D) also detects a direction of travel desired by the second vehicle (2) and, in the presence of the first vehicle (1), the control unit also controls the red phase and / or the green phase for the first vehicle (1) depending on the direction of travel desired by the second vehicle (2). [4] Method according to one of the preceding claims, characterized bythat the direction of travel request of the first vehicle (1) is a turning request, in which case the lane (FG) of an oncoming traffic is crossed in the case of turning. [5] Method according to one of claims 2-4, characterized by that the direction of travel desired by the second vehicle (2) is a turning desire, in which case the lane of oncoming traffic is crossed in the case of turning. [6] Method according to one of claims 2-5, characterized by that the green phase is switched for the first vehicle (1) if no second vehicle (2) is detected and / or the green phase is switched for the first vehicle (1) if the second vehicle (2) is detected and the second vehicle (2) has the same desired direction of travel as the first vehicle (1). [7] Method according to one of the preceding claims, characterized by that the green phase signals an unconditional turn. [8] Method according to one of the preceding claims, characterized by that the first vehicle is in a lane (FS) that allows straight-ahead travel and turning. [9] Method according to one of the preceding claims, characterized by that the detector detects a number of third vehicles (3) which are positioned behind the first vehicle in the first direction of travel (F1) and the control unit (S) controls the red phase and / or the green phase for the first vehicle (1) also depending on the number of third vehicles (3). [10] Method according to one of the preceding claims, characterized by that the detector detects a number of vehicles (2) in a second direction of travel (F2) which is opposite to the first direction of travel, and the control unit (S) controls the red phase and / or the green phase for the first vehicle (1) also depending on the number of vehicles (2) in the second direction of travel (F2). [11] Method according to one of the preceding claims, characterized by in that the detector detects a number of vehicles (1, 3) in the first direction of travel (F1), and the detector detects a number of vehicles (2) in a second direction of travel (F2) which is opposite to the first direction of travel, and the control unit (S) controls the red phase and / or the green phase for the first vehicle (1) also as a function of a difference between the number of vehicles (1, 3) in the first direction of travel (F1) and the number of vehicles (2) in the second direction of travel (F2). [12] System for controlling a traffic light system (LSA), comprising at least one control unit (S) and at least one detector (D), wherein the control unit (S) is designed to generate control signals for a traffic light system (LSA) by means of signals from the detector (D), characterized bythat the detector (D) is designed to detect the presence of a first vehicle (1) and a desired direction of travel of the first vehicle (1) in a first direction of travel (F1), and the control unit (S) is designed to control a red phase and / or a green phase for the first vehicle (1) in dependence on the desired direction of travel of the first vehicle when the first vehicle (1) is present.

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