METHOD FOR CONTROLLING A FLOW OF TRAFFIC ON A ROUNDABOUT

Abstract

A method for controlling a flow of traffic on a roundabout, wherein the flow of traffic is controlled by a traffic control unit by which road users that have entered the roundabout and/or are approaching the roundabout in order to enter it are networked in a network and communicate by way of messages, and wherein, in order to enter, a road user transmits a message containing a request to the traffic control unit provides for entry by the respective road user to be preceded by the flow of traffic that is on the roundabout being determined on the basis of the messages, wherein a message containing a control signal is generated for the respective entering road user in order to communicate whether and/or along which route the road user can travel on the roundabout.

Claims

1. A method for controlling a flow of traffic on a roundabout, wherein the flow of traffic is controlled by a traffic control unit, with which road users, which have entered the roundabout and/or approach the roundabout to enter it, are networked in a network and communicate via messages, and wherein for entering, a road user transmits a request to the traffic control unit as a message, the method comprising: before entry of the respective road user, determining the flow of traffic on the roundabout based on previous messages, and generating a control signal as a message for the respectively entering road user to communicate to the road user when and/or along which route the road user is to enter and/or traverse the roundabout, wherein resources of the roundabout are managed by the traffic control unit, wherein the resources describe a lane or a partial section of the lane, on which the road user is to travel, and the message represents the data of the resources, which are allowed to be used by the entering road user to travel on the roundabout such that it is matched with other road users, wherein the road users get assigned alternative routes for the roundabout if a jam occurs on the roundabout and/or a preceding vehicle on the roundabout fails or has a breakdown, wherein the alternative routes provide a lane change such that the flow of traffic through the roundabout can flow without accident and in uninterrupted manner because the resources of the roundabout can be adapted.

2. The method according to claim 1, wherein the road users on the roundabout emit messages with positioning data and/or destination data and/or route data of the respective road user.

3. The method according to claim 1, wherein routes of all of the road users are determined and/or adapted by the traffic control unit for controlling the roundabout in order that the flow of traffic is guided on the roundabout without accident.

4. The method according to claim 1, wherein it is determined by the traffic control unit based on the messages if a jam is present on the roundabout and/or the entering vehicle is allowed to enter the roundabout.

5. The method according to claim 1, wherein priority is assigned to the respective entering road user before another entering road user according to a temporal order of the requests thereof.

6. The method according to claim 1, wherein the traffic control unit assigns a rank to each road user, wherein a priority and/or subordination with respect to at least one different road user results by the rank, and the flow of traffic on the roundabout is controlled based on the priorities and/or subordinations of the road users.

7. The method according to claim 1, wherein the control signal contains an instruction at least for one road user, which allows the entering road user to enter the roundabout.

8. The method according to claim 1, wherein the control signal indicates a waiting message at least for one road user, which requests the entering road user to wait.

9. A traffic control unit, wherein the traffic control unit is configured to perform a method for controlling a flow of traffic on a roundabout, the method comprising: receiving, from a road user, a request to the traffic control unit as a message; before entry of the respective road user, determining the flow of traffic on the roundabout based on previous messages, and generating a control signal as a message for the respectively entering road user to communicate to the road user when and/or along which route the road user is to enter and/or traverse the roundabout, wherein resources of the roundabout are managed by the traffic control unit, wherein the resources describe a lane or a partial section of the lane, on which the road user is to travel, and the message represents the data of the resources, which are allowed to be used by the entering road user to travel on the roundabout such that it is matched with other road users, wherein the road users get assigned alternative routes for the roundabout if a jam occurs on the roundabout and/or a preceding vehicle on the roundabout fails or has a breakdown, wherein the alternative routes provide a lane change such that the flow of traffic through the roundabout can flow without accident and in uninterrupted manner because the resources of the roundabout can be adapted.

10. The traffic control unit according to claim 9, wherein the traffic control unit is a road side unit.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0028] FIG. 1 shows a schematic representation for illustrating an embodiment of a method.

[0029] FIG. 2 shows a schematic representation for controlling the roundabout based on priorities and subordinations of the road users.

DETAILED DESCRIPTION

[0030] In the embodiments described herein, the described components of the embodiments each represent individual features to be considered independently of each other, which also each develop embodiments independently of each other. Therefore, the disclosure is to include also combinations of the features of the embodiments different from the illustrated ones. Furthermore, the described embodiments can also be supplemented by further ones of the already described features.

[0031] In the figures, identical reference characters each denote functionally identical elements.

[0032] FIG. 1 shows a traffic control unit 20, by which the flow of traffic on a roundabout 10 can be guided. The flow of traffic can include road users 30, 60, which have entered the roundabout 10 and/or approach the roundabout 10 to enter it. The road users 30, 60 can for example be cars, in particular passenger cars and/or a passenger bus. The road users 30, 60 can be autonomously driving cars and/or cars driven by persons and/or they can be motorcycles and/or bicycles.

[0033] The traffic control unit 20 can be a road side unit, which can be employed on and/or at the roundabout 10. The traffic control unit 20 can include a processor (not illustrated). The traffic control unit 20 can serve as a resource manager or user manager to control the resources of the roundabout 10 and/or the flow of traffic of the road users 30, 60 through the roundabout 10. The resources of the roundabout 10 can for example represent lanes and/or lane segments and/or routes of the road users 30, 60 from entering until exiting the roundabout 10.

[0034] The road users 30, 60 can be connected to the traffic control unit 20 via radio links in a data network or briefly network 40, via which they can communicate with each other. For example, the network 40 can be a V2X (vehicle to everything) network and/or V2I (vehicle to infrastructure) and/or V2V (vehicle to vehicle) and/or another communication network. The road users 30, 60 can communicate with the traffic control unit 20 by means of messages 50 via the network 40. The messages 50 can be transmitted by the road users 30, 60 and/or the traffic control unit 20. The messages 50 can contain current positioning data of the road users 30 and/or route data for the road users 30 if they are sent or guided by the road users 30. The messages 50, which are sent by the traffic control unit 20, can for example contain an instruction and/or a control signal, by which the flow of traffic of the roundabout can be controlled.

[0035] By the messages 50 of the road users 30, the traffic control unit 20 can determine when which road user 30 arrives at the roundabout 10 and/or where it is located on the roundabout 10. By the positioning data and destination data of the road users 30, which the road users 30 transmit to the traffic control unit 20 via the network 40, the traffic control unit 20 can determine when which arriving road user 60 can enter the roundabout. In addition, the traffic control unit 20 can use this data to determine a route or generally resources of the road users 60 for the subsequent travel through the roundabout 10. Thus, a resource assignment to the road users 60 is effected.

[0036] If an entering road user 60 approaches the roundabout 10, it can emit a message 50 to the traffic control unit 20. The message 50 of the entering road user 60 can contain a request for entering and/or information relating to the current position of the road user 60 and/or a planned destination and/or direction of travel or target exit of the entering road user 60. Based on the messages 50 and/or sensor data of the entered road users 30, the traffic control unit 20 can ascertain the current traffic situation, e.g., a jam and/or the availability of the resources of the roundabout 10. Based on the current traffic situation of the roundabout 10, the traffic control unit 20 can generate a message 50, which can be sent to the entering road user 60.

[0037] This message 50 of the traffic control unit 20 can contain a corresponding control signal, by which it is communicated to the entering road user 60 if it can enter the roundabout 10 or has to wait at the roundabout 10. This message 50 can contain route data of the route to be traveled or generally resource data of the resources assigned to the road user. The control signal can represent an instruction for entering or an entry signal for the entering road user 60 if a jam is not present on the roundabout 10 and/or the resources of the roundabout 10 are freely available. The control signal can represent a waiting message or a waiting signal for the entering road user 60 if the resources of the roundabout 10 are fully exhausted and/or a jam on the roundabout 10 is ascertained by the traffic control unit 20.

[0038] The traffic control unit 20 can select the resources of the roundabout 10 to be used and/or the route data of the road users 30 by the message 50 such that the flow of traffic through the roundabout 10 can be ensured without delay and/or without accident. By the route data, it can for example be considered when a road user 30 has a breakdown on the roundabout 10 and/or an accident occurs on the roundabout 10. In such a case, alternative routes or alternative lanes in case of a multi-lane roundabout 10 can be provided to the subsequent road users 30. Hereto, an adaptation of the association of the resources of the roundabout 10 is effected. The adaptation of the association of the resources of the roundabout 10 can also be effected if a road user 30, 60 with a certain priority has to travel through the roundabout 10. For example, the road users, which are involved with rescue services, can have priority with respect to the normal traffic. The lanes or routes, which are currently used by the entered road users, can be released and/or adapted in order that the road users for the rescue services can travel through the roundabout without having to stop. A road user for a rescue service can be an ambulance and/or a police vehicle and/or a fire truck.

[0039] The traffic control unit 20 can also serve as a virtual traffic light 80, by which the flow of traffic through the roundabout 10 can be controlled in case of high traffic densities or multiple entering road users 60 per direction to the roundabout 10. In other words, a control signal of the traffic control unit 20 can serve as a green light or a red light for controlling the entering traffic.

[0040] FIG. 2 shows a roundabout 10, through which the road users V1, V2, V3, V4 can be guided by the traffic control unit 20 based on a ranking with priority and/or subordination. The priorities and/or subordinations can be preset by rules, which can already be provided to the traffic control unit 20. Here, the general traffic regulations for guiding the road users V1, V2, V3, V4 through the roundabout 10 based on priorities or subordinations can apply (e.g., a roundabout with “yield to the right”). The road user V1, which has already traveled on the roundabout 10, can for example have priority with respect to the entering road users 60. Additionally or alternatively, the ranks can be determined by a respective category of the road users (e.g., rescue service or private).

[0041] Based on the messages 50 of road users V1, V2, V3, V4, the traffic control unit 20 can ascertain route data currently required by the road users V1, V2, V3, V4 and thus ascertain how the road users V1, V2, V3, V4 have to behave on the roundabout 10 to obtain a coordination. The route data can for example describe lanes and/or lane segments and/or routes of the roundabout 10, on which the road users V1, V2, V3, V4 have to travel through the roundabout 10. The routes R1, R2, R3 can be assigned to the road users V1, V2, V3, V4 by the traffic control unit 20.

[0042] In an embodiment, the routes R1, R2, R3 of the roundabout 10 for the road users V1, V3, V3, V4 only have to be planned by the traffic control unit 20 if the road users V1, V2, V3, V4 obtain a message for entering from the traffic control unit 20. The entering road users V2, V3, V4 each follow the routes R1, R2, R3. The entered road user V1, which travels on the route R1, can have priority with respect to the road users V2, V3 and further travel through the roundabout 10. The entering road users V2, V3 have to wait since the route R1 can be traveled by the road user V1. The entering road users V2, V3 can receive a waiting message from the traffic control unit 20 in order that a risk of accident can be avoided. Since the route R3 is not planned for the entered road user V1, this resource is available, and thus it can be signaled to the entering road user V4 by the traffic control unit 20 to travel on without having to wait at the roundabout 10.

[0043] The traffic control unit 20 can define a time window in the waiting message, in which the road users V2, V3 have to wait at the roundabout. For example, the time window can be 30 or 60 for example in a time range of 5 to 60 seconds. The time window can be determined by the traffic control unit 20 based on the current positioning and/or speed of the road user V1. The entering road user V2 can for example have a small time window for waiting with respect to the road users V3 and V4 because the road user V2 has to follow the road user V1 or travel on the same route. The time window can be increased if the entered road user V1 moves very slowly or with a speed on the roundabout 10, which is lower than a normal or admissible speed. The slow speed can for example be in the range from 0 (breakdown or jam) to 30 km/h. The time window can also depend on the fact if the entered road user V1 has signaled to the traffic control unit 20 that it has arrived at the exit. In other words, the traffic control unit 20 can ascertain exiting the roundabout 10 by the road user V1 based on the messages 50 and/or sensor data in order that the time window can be calculated and/or adapted for respectively entering road users. The time window for the entering road users V2, V3 can for example be decreased if the traffic control unit 20 already knows that the road user V1 has traveled through the roundabout 10. The time window for the entering road users (e.g., V3) can then be calculated depending on route data and/or destination data and/or parameters of the next following entered road user (e.g., V2), which can be ascertained in real time. The real-time parameters can for example represent an instantaneous speed and/or current positioning of the entered road user. By the route data and the real-time parameters of the entered road user V2, the traffic control unit 20 can calculate or estimate a travel time, which the road user V2 requires to exit the roundabout 10 or to release the resources (e.g., use of lanes) of the roundabout 10, which can be assigned to the entering road user V3. After elapse of the waiting time determined in the time window, it can be signaled to the respectively entering road users to enter the roundabout 10. The traffic control unit can first signal to V2 for entering because it can travel behind V1 through the roundabout 10. The time window can be calculated with an algorithm in the traffic control unit 20.

[0044] It can be signaled to the entering road user V2 to wait if the road user V3 has entered the roundabout 10 or has previously obtained a green light for entering. The road user V3 can obtain a waiting message for waiting from the traffic control unit 20 if the road user V4 has entered the roundabout 10. Since the traffic control unit 20 can determine the exact positioning of the entered road users based on the messages 50, the entering traffic can be controlled such that the use of the resources can also be optimized.

[0045] In order that automated road users can be safely guided through a roundabout, thus, the employment of an RSU may be provided. The RSU serves as a user manager and resource manager and has an overview of the environment by, e.g., support of cameras. By usual V2X messages, an

[0046] RSU receives the information of the different networked road users and can calculate from it when which road user arrives at the roundabout or where it is located on the roundabout. By positioning data and route data, which the road users transmit to the RSU via V2X, the RSU can determine when which road user can or is to enter the roundabout, and uses this data to determine the route and resources of the subsequent road users for the travel through the roundabout. Since the RSU knows about all users, it can better divide the resources and lead the road users to the correct lanes and possibly give priorities and subordinations to further keep the traffic flowing. This system functions for all types of roundabouts.

[0047] By this technique, a possibility of guiding automated and networked vehicles through roundabouts of all kinds arises. The control unit RSU (traffic control unit) calculates the best routes of all of the users and assigns them to each road user. It also helps the traffic flow increase and accident reduction.

[0048] Overall, the examples show how a method for controlling a flow of traffic on a roundabout can be provided.

[0049] Aspects of the various embodiments described above can be combined to provide further embodiments. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled.