Researchers Farhang Motallebi Araghi, Armin Abdolmohammdi, Navid Mojahed, and Shima Nazari from the University of California, Riverside, have developed a new approach to optimize the deployment of mobile fast chargers for off-road heavy equipment. Their work, published in the journal Transportation Research Part E: Logistics and Transportation Review, addresses the challenges of electrifying remote sites with limited fixed charging infrastructure.
The researchers formulated a fleet size and mix capacitated vehicle routing problem with time windows (FSMCVRPTW) for mobile fast charging vehicles (MFCVs). This approach jointly optimizes fleet composition, charger specifications, routing, and scheduling within a single mixed-integer linear program. The model considers various MFCV types with different power ratings, battery capacities, fuel range, and cost structures. It aims to minimize total daily costs, including labor, fuel, amortized capital expenditure, and energy purchase, while adhering to service windows, resource budgets, and energy-delivery constraints.
The researchers implemented their model using Python and Gurobi and applied it to two case studies using California Department of Transportation wheel-loader data. One case study focused on a dense urban environment in Los Angeles, while the other examined a sparse mountainous area in Truckee. The results demonstrated that simultaneous optimization yields compact, well-utilized fleets that meet all service windows. The analysis also revealed strong sensitivity of unit cost to demand density and geography.
For the energy sector, this research provides a practical tool for optimizing the deployment of mobile fast chargers. By co-designing fleet size, charger power, routing, and service schedules in a single optimization layer, energy companies can achieve context-aware, cost-efficient mobile fast charging solutions. This approach is particularly valuable for electrifying remote sites with limited fixed charging infrastructure, ensuring reliable and efficient energy delivery to off-road heavy equipment.
Source: Motallebi Araghi, F., Abdolmohammdi, A., Mojahed, N., & Nazari, S. (2023). Fleet size and mix capacitated vehicle routing problem with time windows for mobile fast chargers. Transportation Research Part E: Logistics and Transportation Review.
This article is based on research available at arXiv.