Journal of Field Robotics Journal of Field Robotics Ground robotics in tunnels: Keys and lessons learned after 10 years of research and experiments Tardioli Danilo Riazuelo Luis Universidad de Zaragoza Sicignano Domenico Universidad de Zaragoza Rizzo Carlos Lera Francisco Universidad de Zaragoza Villarroel José L. Universidad de Zaragoza Montano Luis Universidad de Zaragoza 2019 research-article