DOI: 10.3390/buildings16183724 ISSN: 2075-5309

Replenishment-Aware Operation Scheduling for a Single Asphalt Crack Repair Robot

Libo Wang, Wen Yang, Dong Xu, Hongwei Zhang, Xiangui Wang, Zhaibang Ke, Wenkang Zhang

Autonomous asphalt crack repair robots can reduce workers’ exposure to traffic and improve the repeatability of pavement maintenance, but their field productivity depends on operation-level scheduling as well as crack perception and sealing control. This paper formulates a single-robot asphalt crack repair problem in which all detected cracks in an operation zone must be repaired under finite sealant capacity and explicit replenishment returns. A compact mixed-integer programming model is developed, NP-hardness is established, and an adaptive large-neighborhood search with a dynamic-programming replenishment decoder (ALNS-DP) is proposed. The method separates crack-sequence search from exact replenishment-feasible segmentation for each candidate sequence. Twelve anonymized real operation-zone cases from Hefei, China, containing 18–64 cracks are used for evaluation, and six algorithms are run ten times on every case. Compared with the strongest stochastic baseline, ALNS-DP reduces the mean final objective by 5.11% on average, with case-level reductions ranging from 0.40% to 8.52%; on the representative Case-08, the objective reduction is 6.86%. Small exact MIP benchmarks with 8–12 cracks give 0.00% optimality gaps for ALNS-DP. Additional replenishment-location, material-demand-error, ablation, scalability, and statistical tests show that the main advantage comes from coupling sequence search with replenishment-aware decoding rather than from omitting difficult cracks.