Automatic guided vehicle (AGV) fleet management always plays a significant role in smart manufacturing, which is widely studied as a representative nondeterministic polynomial-hard combinatorial optimization problem. With more smart factories featuring specialization in production line and human-robot interaction, AGVs are commonly bound with specific tracks, loading and unloading stations, which makes the current routing algorithms fail to play their path searching ability in complicated network topology. Thus, an integrated timetable optimization and AGV dispatching (TOAD) model is proposed aimed at such case, shifting the emphasis of routing to station selection and route selection from the perspective of timetable designing, while still considering the mixed directivity of layout, conflict avoidance, AGV availability and charging requirements. Targeted at makespan minimization, an improved genetic algorithm (GA) is used for solution with a heuristic operator to seek a better solution within shorter time. The proposed method is evaluated using an empirical factory case study with field data as input, with a comparison with the exact algorithm and standard GA. Results show that a smaller makespan and a shorter computation time can be obtained by the proposed TOAD model in large-scale scenarios, demonstrating a promising application prospect.

The increasingly complicated urban traffic patterns lead traffic signal control to a new trend of higher flexibility and quicker response, which becomes possible with advances in both sensor technology and artificial intelligence. Though in its early stage, existing intelligent signal controllers equipped with reinforcement learning (RL)-based feature extractor and large language model (LLM)-driven scenario understanding and decision support already demonstrate powerful data digesting ability. This study thus proposes a smart traffic light control system integrating a vision-based perception tool to extract traffic state from real-time snapshot image of the intersection, and an LLM agent controller for signal phase switching upon scenario analysis. An indicator describing the urgency for green time at phase level is defined to abstract the contextual information regarding the competition of multiple approaching traffic flows, which augments the LLM with domain-specific logical reasoning for signal control action generation, aimed at assigning green time to the flows with the most compelling needs. With a RL-based controller providing initial control decision as backup, the proposed method is able to handle both pre-trained and out-of-distribution scenarios through real-time traffic state diagnosis and knowledgeable reasoning. Simulation evaluation on different intersection layouts and vehicle compositions is conducted with horizontal comparison of five benchmarks. A decrease in average waiting time was realized by more than 5 % under normal traffic scenario and 20 % under emergency vehicle scenario, respectively. Further, comprehensive analysis was conducted to explore the applicability of the proposed method and feasibility for real-world application in unmanned aerial vehicle (UAV)-based intelligent traffic management.

With the emergence of innovations associated with public transport (PT) services, such as Mobility-as-a-Service, demand responsive transit, and autonomous vehicles, the door-to-door PT journey is achievable via multiple transfers between and within different PT modes. As such, seamless transfers between different modes of public transportation become an increasingly important factor for the attractiveness of PT services. At the same time, recent developments in travel time prediction methodologies offer new, reliable data sources for the optimization of PT operations. This work, with the consideration of these two elements, develops a mixed integer linear programming model for the PT schedule synchronization problem. The novelty is threefold. First, a novel concept of path-oriented scheduling is proposed. The path transfer time is explicitly formulated and minimized to provide a seamless travel experience considering that the emerging multimodal mobility inevitably induces multiple transfers. Second, time-dependent travel time data is also utilized in the model, which allows us to harness new and more representative data sources for improving PT services. Third, in order to complement the increase in computational complexity as a result of the utilization of time-dependent travel time data, three novel valid inequalities (VIs) are derived. Numerical studies show that the use of time-dependent travel time data is beneficial in terms of reducing path transfer times, when compared to using the mean historical travel times. The numerical study also reveals a tradeoff between the maximum allowable path transfer time and trip time. Using simulation studies on three bus lines in Copenhagen, we demonstrate that the valid inequalities could reduce the computation time by 8.5% on average, where the maximum reduction of computation time could reach 54.0%. The proposed valid inequalities are benchmarked against two classes of valid inequalities in the literature. It is found that the proposed valid inequalities could outperform those in the literature. We also found that further improvement in computational performance can be attained by using a combination of the proposed valid inequalities.