Design and power management of a solar‐powered “Cool Robot” for polar instrument networks

Abstract

The Cool Robot is a four-wheel-drive, solar-powered, autonomous robot designed to support summertime science campaigns in Antarctica and Greenland over distances exceeding 500 km. This paper provides an overview of key features of the robot, including design for good mobility, high efficiency, and long-term deployment under solar power in harsh polar environments. The Cool Robot's solar panel box, comprising panels on four sides and a top panel, encounters insolation variations with a bandwidth of up to 1 Hz due to sastrugi. The paper details a unique photovoltaic control algorithm to accommodate these variations. We deployed the robot at Summit Camp, Greenland to validate its mobility and power budget and to assess the photovoltaic control system. The 61 kg robot drove continuously at 0.78 m/s on soft snow, its 160 W average power demand met by solar power alone under clear skies above 16°sun elevation. The power-control system reliably matched input with demand as insolation varied during testing. A simple GPS waypoint-following algorithm provides low-bandwidth path planning and course correction and demonstrated reliable autonomous navigation during testing over periods of 5-8 h. Field data validate the Cool Robot design models and indicate that it will exceed its design goal of carrying a 15 kg payload 500 km across Antarctica in 2 weeks. A brief description of instrument payloads and scientific studies aided by networks of such autonomous solar robots is provided.

Autonomous rover for polar science support and remote sensing

“…Its operating speed is approximately 3 km/h and it is programmed to be operated either manually, through a radio link, or autonomously through GPS waypoint following. The original solar panel box, described in [1][2][3] provided a peak power of ~300 W for diffuse-sky radiation, r = 0 on May 21 or July 21 at 80 degrees North latitude. The solar panel box was redesigned to increase peak power and reduce robot height, increasing the wind tip-over speed.…”

“…Its original design, development, and performance are described in [1][2][3]. In this project, we extended the performance and improved human factors in operation of the power, control, and communications systems for reliable, long-duration summertime deployment over polar snowfields, and we integrated scientific instrument payloads.…”

An Unmanned Tracked Vehicle for Snow Research Applications

“…Cold Regions Research and Engineering Laboratory (CRREL), USA has designed and developed an autonomous solar driven ground vehicle called, Cool Robot 8 , for providing assistance during scientific expeditions in Antarctica and Greenland. The 61 kg vehicle was designed with solar panels fitted on its four sides and at top to maximise utilisation of solar power.…”

Autonomous GPR Surveys using the Polar Rover Yeti

“…Yeti is a second‐generation oversnow rover developed through collaboration between Dartmouth College and the Cold Regions Research and Engineering Laboratory (CRREL). Its design philosophy follows that of the Cool Robot (Lever & Ray, ; Ray, Lever, Streeter, & Price, ) emphasizing simplicity, energy efficiency, and low weight to achieve reliable performance in demanding polar conditions.…”

“…We used the Cool Robot mobility analyses (Lever & Ray, ; Ray et al., ) to design Yeti , due to its similar 4WD configuration and weight. We intended Yeti to support traverse operations during the active, summertime seasons in Antarctica and Greenland.…”