Evaluating the Impacts of Optimization Horizon on the Shared Autonomous Vehicle Reservation Request System

With the development of technology, shared autonomous vehicles may become one of the main traffic modes in the future. Especially, shared autonomous vehicle reservation system, commuting, and other trips with fixed departure time mostly submit their travel requests in advance. Therefore, it is important to reasonably match shared autonomous vehicles and reservation demands. In this paper, reservation requests are divided into short-term and long-term requests by inputting requests in a more realistic way. An integer linear programming model considering operator scheduling cost and system service level is established. A detailed scheme considering rolling horizon continuity and ridesharing is used to improve the dispatching result. Based on traffic data in Delft, the Netherlands, 164 scenarios are tested in which the parking cost, fuel cost, ridesharing effect, service level, and network size are analyzed. The results show that a better relocation and ridesharing matching scheme can be obtained when the rolling horizon is small, while the overall effect is better when the rolling horizon is large. Moreover, the buffer time, distance, and travel time limit for vehicle relocation should be selected according to the request quantity and the calculation time requirement. The result can provide a suggestion for the dispatching of shared autonomous vehicle reservation system with ridesharing.

Combining Fix and Relax Heuristic and LP-Metric Method to Solve the Multi-Objective Integrated Production-Routing Problem

Production routing problem is one of the problems of the integrated planning that interests in optimizing simultaneously production, inventory, and distribution planning. This chapter has the purpose of developing two mono-objective models for the production-routing problem: one of them minimizes the total costs which is the classical objective while the other one minimizes the energy consumed by the production system. A bi-objective model is then proposed to combine the two objectives mentioned previously using LP-metric method. To solve big instances of the problem in reasonable time, an approximate approach is proposed using the rolling horizon-based fix and relax heuristic. Finally, computational results are presented to compare the solutions obtained by both approaches.

Electricity demand flexibility potential of optimal building retrofit solutions

Swiss buildings, the majority of which will last beyond 2050, are responsible for a large share of energy demand and greenhouse gas emissions. Hence, building retrofit is considered as one of the most promising approaches to reduce those shares. However, reducing the energy load should not be an end in itself. The continuous integration of intermittent power sources in the electricity grid imposes new challenges to the supply-demand problem that might directly affect the retrofit process and vice-versa. Therefore, this paper aims to develop a model to analyze the demand flexibility potential of optimal retrofit solutions. Co-simulation and a rolling horizon approach are used to derive upper and lower electricity consumption profiles given some temperature comfort bands. Within those electricity bands, the feasible area provides insights on the extent by which the electricity consumption can be shifted within the comfort constraints. The method is applied to a building archetype. Results show that when the comfort constraints are relaxed the feasible area increases, e.g., up to five times for the case of enhancing the roof insulation, while building retrofit influences the electricity bands. Such a method could enhance the retrofit process and address both the emissions’ and the supply-demand balancing problem.