Method of controlling a traffic system, apparatus, computer program, and computer-readable storage medium
A method of controlling a traffic system having a plurality of intersections with switchable traffic lights and road sections located between the intersections includes detecting traffic loads of multiple relevant road sections, determining a local stress function for each relevant road section depending on the detected traffic load of the respective relevant road section, determining a global stress function for the entire traffic system based on the local stress functions, determining, using a quantum concept processor, improved switching times for the traffic lights of the intersections adjacent to the relevant road sections, wherein the improved switching times are determined such that the global stress function reaches a smallest detectable value, and switching the traffic lights according to a switching model based on the improved switching times.
1. A method of controlling a traffic system having a plurality of intersections with switchable traffic lights and road sections located between the intersections, the method comprising:
detecting traffic loads of multiple relevant road sections,
determining a local stress function for each relevant road section depending on the detected traffic load of the respective relevant road section,
determining a global stress function for the entire traffic system based on the local stress functions,
determining, using a quantum concept processor, improved switching times for the traffic lights of the intersections adjacent to the relevant road sections simultaneously, wherein the improved switching times are determined such that the global stress function reaches a smallest detectable value, and
switching the traffic lights according to a switching model based on the improved switching times.
2. The method according to claim 1 , wherein the global stress function is defined as a quadratic optimization term or as a QUBO (Quadratic Unconstrained Binary Optimization) term.
3. The method according to claim 1 , wherein the smallest detectable value of the global stress function is a local or absolute minimum of the global stress function.
4. The method according to claim 1 , wherein the determining of the local stress function is additionally performed based on selected values for different possible green phases for traffic lights adjacent to the respective relevant road section.
5. The method according to claim 1 , further comprising:
loading historical data of the traffic system, wherein further the determining of the local stress functions is performed taking into account the historical data.
6. The method according to claim 1 , wherein the determining of the local stress functions, the determining of the global stress function, the determining of the improved switching times, and the switching of the traffic lights is periodically repeated and the improved switching times are constantly determined for a next switching period.
7. The method according to claim 6 , wherein the detecting of the traffic loads is periodically repeated.
8. The method according to claim 1 , wherein a number of vehicles on the respective relevant road section is detected for detecting the traffic loads.
9. The method according to claim 1 , wherein current switching times of the traffic lights of intersections adjacent to the respective relevant road section are further taken into account to determine the local stress function.
10. An apparatus that controls a traffic system with a plurality of intersections with switchable traffic lights and road sections located between the intersections, the apparatus comprising:
at least one sensor arranged to detect traffic loads of multiple relevant road sections,
a computing unit arranged to determine a local stress function for each relevant road section depending on the detected traffic load of the respective relevant road section and arranged to determine a global stress function for the entire traffic system based on the local stress functions,
a quantum concept processor arranged to determine improved switching times for the traffic lights of the intersections adjacent to the relevant road sections simultaneously, the improved switching times being determined such that the global stress function reaches a smallest detectable value, and
a switching device arranged to switch the traffic lights in accordance with a switching model, the switching model being based on the improved switching times.
11. The apparatus according to claim 10 , wherein the quantum concept processor is a processor arranged to solve an improvement problem using quantum annealing simulation.
12. A non-transitory computer-readable storage medium on which a computer program comprising instructions that, when the program is executed by a computing device, cause the computing device to perform the method of claim 1 is stored.