Theoretical Foundations for Decentralized Cooperative Control of Multi-Unmanned Aerial Vehicle Systems for Disaster Response Operations in Nigerian Urban Environments

Urban disaster response operations in densely populated Nigerian cities including Lagos, Kano, and Port Harcourt, encompassing flood rescue, building collapse search and rescue, and emergency medical supply delivery, present complex operational environments for autonomous unmanned aerial vehicle systems where centralized control is infeasible and robust cooperative behaviour among multiple UAVs under communication constraints and dynamic obstacle populations must be guaranteed. This dissertation develops theoretical foundations for decentralized cooperative control of multi-UAV systems applied to disaster response operations in Nigerian urban environments. A formal mathematical model of the Nigerian urban disaster response multi-UAV problem is developed as a decentralized partially observable Markov decision process with asynchronous communication and heterogeneous vehicle capabilities. A novel graph-theoretic cooperative control framework is derived in which inter-UAV cooperation emerges from local communication-limited consensus protocols with provably bounded sub-optimality relative to the fully centralized solution. A conflict resolution mechanism for guaranteed collision avoidance under limited communication is developed using differential game theory, yielding closed-form avoidance manoeuvre policies that can be evaluated onboard UAVs with restricted computational resources. An original UAV trajectory optimization algorithm exploiting the specific geometric structure of Nigerian urban airspace, characterized by rectilinear street grid overlaid with informal settlement structures, is derived. Experimental validation using a four-UAV swarm in a simulated disaster response exercise conducted at the Ojota floodplain in Lagos demonstrates 87 percent area coverage completeness in 12 minutes with zero inter-UAV collisions across 15 independent trial runs. Keywords: multi-UAV cooperation, decentralized control, disaster response, urban airspace, Nigeria