Near Field Wireless Power Transfer via Robotic Feedback Control

Unmanned rover application plays a key role in planetary exploration, where power and efficiency is paramount. The approach utilized in this work allows for near field wireless power transfer in remote locations with minimal support. The ability to establish a micro-grid power system connection autonomously using wireless power, eliminates the arduous task of designing a complex, multiple degrees of freedom (MDOF) robotic arm. The work presented in this paper, focuses on both the hardware and software within the micro-grid system. This particular near field wireless system consists of a primary and secondary set of modules, comprised of Litz wire coils, which are inductively coupled to complete the circuit. Both the primary and secondary modules contain a shunt resistor circuit, as well as a potential divider circuit and an Arduino controller (used to collect and analyze recorded data). The aforementioned hardware, allows for quantitative measurement of voltage, current, and power of the primary and secondary modules. Robot rover docking is accomplished using camera visualization, wheel odometry, and GPS data; all of which, are provided by the Robot Operating System (ROS). Various docking poses are used to characterize overall power transfer and efficiency at diverse alignments. Using collected data from the near field power modules' Arduino controllers and ROS, power from the coils is measured as functions of both the distance between coils and associated yaw angle. Power transfer efficiency is then evaluated using compiled power data. A dynamic feedback control system optimizes power transfer efficiency and docking alignment. The feedback control system acts as the driving force for re-docking the robot and further enhancing efficiency of the proposed near field power connection. In its entirety, the research paper explores the physical and mathematical relationships used to develop the dynamic feedback control system.