Decentralized Optimal Merging Control for Connected and Automated Vehicles

This paper addresses the optimal control of Connected and Automated Vehicles (CAVs) arriving from two roads at a merging point where the objective is to jointly minimize the travel time and energy consumption of each CAV. The solution guarantees that a speed-dependent safety constraint is always satisfied, both at the merging point and everywhere within a control zone which precedes it. We first analyze the case of no active constraints and prove that under certain conditions the safety constraint remains inactive, thus significantly simplifying the determination of an explicit decentralized solution. When these conditions do not apply, an explicit solution is still obtained that includes intervals over which the safety constraint is active. Our analysis allows us to study the tradeoff between the two objective function components (travel time and energy within the control zone). Simulation examples are included to compare the performance of the optimal controller to a baseline with human-driven vehicles with results showing improvements in both metrics.Comment: 16 pages, 2nd version, 20 figure

Decentralized optimal merging control for connected and automated vehicles with safety constraint guarantees

This paper addresses the optimal control of Connected and Automated Vehicles (CAVs) arriving from two roads at a Merging Point (MP) where the objective is to jointly minimize the travel time and energy consumption of each CAV. The optimal solution can be used as a reference for tracking control and it guarantees that a speed-dependent safety constraint is satisfied both at the MP and everywhere within a Control Zone (CZ) which precedes it. We analyze the case of no active constraints and prove that under certain conditions the safety and speed constraints remain inactive, thus significantly simplifying the determination of an explicit decentralized solution. When these conditions do not apply, a complete solution is still obtained which includes all possible constraints becoming active. Our analysis allows us to study the tradeoff between the two objective function components (travel time and energy within the CZ). Simulation examples are provided to compare the performance of the optimal controller to a baseline consisting of human-driven vehicles with results showing improvements in both metrics.Accepted manuscrip

Korištenje policijskog sustava upozoravanja za otklanjanje pogrešaka u inteligentnim sustavima otkrivanja prekršaja

A broad range of diverse technologies under the generic topic of intelligent transportation systems holds the answer to many transportation problems. Tailgating and the failure to maintain sufficient distance from the next vehicle are among the biggest causes of motorway accidents. There are intelligent systems to detect this violation. Their insufficient accuracy is, however, the reason they are used with reluctance. In this research, a police warning system is proposed to note the detected violating drivers by a short message service. If the violation is repeated, the driver will be fined. Using robability logic, it has been shown that by the proposed system, we can be sure that the error in traffic ticketing will be very low. A survey of police officers found that most of them welcome the proposed system.Širok raspon raznih tehnologija obuhvaćenih pod generičkom temom inteligentnih prometnih sustava nudi odgovor na mnoge probleme u prometu. Vožnja na repu i neodržavanje dovoljnog razmaka iza drugog vozila među najvećim su uzrocima nesreća na autocestama. Iako postoje inteligentni sustavi za otkrivanje ovakvih prekršaja, nevoljko se koriste zbog njihove nedostatne preciznosti. Ovim se istraživanjem predlaže policijski sustav upozoravanja koji bi uslugom kratkih poruka bilježio vozače zatečene u kršenju pravila. U slučaju ponovljenog kršenja, vozaču se izriče novčana kazna. Koristeći se logikom vjerojatnosti, razvidno je da se predloženim sustavom mogu znatno smanjiti pogreške pri izricanju prometnih kazni. Anketa provedena među policijskim službenicima pokazuje da većina njih pozdravlja predloženi sustav

Development of mathematical models to improve road freight movements for tunnel infrastructure using connected and autonomous vehicles

Road freight transportation is considered the backbone of country’s socio-economic framework and thus its vital to ensure it is working optimally. The research detailed in this thesis is focused on improving the movement of road freight, especially for hazardous goods vehicles via a road tunnel, with the help of Connected and Autonomous Freight Vehicles (CAV-F). The study analyses real-world Dartford Crossing tunnel data to identify the impact of existing check and allow procedures for Dangerous Goods Vehicles (DGVs) and Abnormal Load Vehicles (ALVs) at a tunnel. A near realistic traffic simulation model is developed as part of analysis and is validated against an independent Highways England’s Motorway Incident Detection and Automatic Signalling (MIDAS) data. The effectiveness of CAV-F in improving road traffic conditions is measured using different simulation scenarios involving mixed traffic (i.e. CAV-F and conventional vehicles alongside) and different real-world tunnel closure conditions. Once the effective performance of CAV-F is established, this research develops a novel mathematical model aimed at automating the check and allow procedures for DGVs at the tunnel. The mathematical model calculates the geo-reference locations for the placement of cooperative communications between the vehicles and road infrastructure to generate dynamic vehicular gaps. This will allow desired safety gaps between the platoon of DGVs and its preceding and following vehicles enabling isolated travel via the road tunnel to ensure safe and secure passage. The mathematical model is verified for different road layouts determined based on geo-referenced locations, approaching a road tunnel. Using traffic simulation, the results determine if the modulation of vehicles’ speeds at identified geo-referenced locations are suitable for desired gap generation. Finally, to conclude the research questions, the second mathematical model is developed to help uninterrupted traffic merging at the junctions, as was observed after the successful gap generation. This model could also be generalised to optimise the traffic merge sequence at a motorway junction. The approach is inspired by the noise cancellation technique which utilises destructive wave interference patterns, where vehicular flow on two merging roads is considered as traffic waves. By analysing the merge sequence of vehicles at the junction from fixed equidistant positions on separate roads, the dynamic phase shifting is applied by modulating the speeds of the identified vehicles which would otherwise approach at the junction simultaneously, leading to queue formation (or collision). The performance of the approach is then measured using a traffic simulation model and are determined against existing real-world traffic flow on motorways for improvements in travel time, and traffic throughput and reduction in congestion, with increasing traffic density