SMT-Based Optimal Deployment of Mobile Rechargers

Abstract

Efficient recharging is an essential requirement for autonomous mobile robots. In an indoor robotic application, charging stations can be installed offline. However, frequent trips to the charging stations cause inefficiency in the performance of the mobile robots. In an outdoor environment, a charging station cannot even be installed easily. We propose a framework and algorithms for enabling a group of mobile wireless rechargers to fulfill the energy requirement of autonomous mobile robots in a workspace efficiently. Our algorithm finds the optimal trajectories for the mobile rechargers in such a way that once there is a need for a recharge, the robots do not need to spend significant time and energy to get access to a recharger. Our algorithm is based on a reduction of the problems to Satisfiability Modulo Theory (SMT) solving problems. We present extensive experimental results to show that the optimal trajectories for mobile rechargers can be generated successfully for different types of robots and workspaces within a reasonable time. Moreover, a comparison with the performance of static charging stations establishes that mobile rechargers are more effective in terms of allowing the autonomous robot to continue their work for a longer time.