This proposal will support fundamental research to engender a self-powered autonomous robot to prevent electric power line defects. The US power grid is more than half-a-century old and runs more than 150,000 miles, often in remote locations. The overhead power lines (PLs) are exposed to harsh environments such as wind-induced vibrations (WIV), which limit their lifespan. Conventional techniques for suppressing the unwanted WIV rely on fixed passive vibration absorbers (FPVAs). These FPVAs are often ineffective because of their narrow frequency bandwidth, and inability to adapt to the changing wind characteristics. This poor WIV control contributes to fatigue damage in the strands of the cable, eventually resulting in PL failure. Relatedly, PL inspection and maintenance are often required because of fatigue damage and acid rain corrosion of the cables. These inspections are mostly conducted through foot patrol or helicopter-assisted inspection; both techniques are laborious, expensive, and dangerous to the maintenance personnel. Recently, PL inspection robots have emerged, but their implementations have been hindered by their bulky size, heavy weight, short operation time, energy inefficiency, and hefty price tag. In view of these shortcomings, this CAREER project proposes a shift from FPVAS and bulky robots to a multi-functional self-powered autonomous robot (SPAR) for intelligent vibration control and monitoring of PLs. However, the realization of such a robot requires a fundamental understanding of the nonlinear dynamic interactions between wind forces, a vibrating-cable, and a mobile robot. Such a problem has not been explored yet. The research goal of this project is to create the fundamental tools that will enable the construction of SPAR, which will help make US power grids smarter, more sustainable, and more robust. The educational and outreach impacts of this proposal are to broaden the representation and retention of underrepresented minority in the STEM field, enable dissemination and commercialization of the research findings to the power industry, and establish an interdisciplinary course focusing on nonlinear dynamics of electromechanical systems for graduate students and professional engineers.
SPAR will provide fundamental breakthroughs at the interface of energy harvesting, fluid-structure interactions, and vibration control. The proposed research tasks are: (1) the construction of a multiphysics model to study wind-cable-robot interactions, (2) the creation of an effective and adaptive electromagnetic energy harvester to power the robot, (3) the development of a WIV control framework to optimize vibration suppression, and (4) the establishment of a testbed to experimentally investigate the performance of SPAR. This CAREER grant will advance scientific knowledge in the following ways. First, the multiphysics model will create a fundamental understanding of how a fluid interacts with an elastic continuum coupled with a traveling robot. Second, the simultaneous adaptive energy harvesting and vibration control technique will provide understanding of broadband energy harvesting and vibration suppression of infinite dimensional systems via passive self-tuning and active tracking of equilibrium positions. Overall, this CAREER will augment our understanding of simultaneously harvesting energy and controlling WIV of continuum systems.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
