James Teza

First Experiments in the Robotic Investigation of Life in the Atacama Desert of Chile

The Atacama Desert of northern Chile may be the most lifeless place on Earth, yet where the desert meets the Pacific coastal range desiccation-tolerant micro-organisms are known to exist. The gradient of biodiversity and habitats in the Atacama’s subregions remain unexplored and are the focus of the Life in the Atacama project. To conduct this investigation, long traverses must be made across the desert with instruments for geologic and biologic measurements. In this paper we motivate the Life in the Atacama project from both astrobiologic and robotic perspectives. We focus on some of the research challenges we are facing to enable endurance navigation, resource cognizance, and long-term survivability. We conducted our first scientific investigation and technical experiments in Chile with the mobile robot Hyperion. We describe the experiments and the results of our analysis. These results give us insight into the design of an effective robotic astrobiologist and into the methods by which we will conduct scientific investigation in the next field season.

Design and field experimentation of a prototype Lunar prospector

Scarab is a prototype rover for Lunar missions to survey resources in polar craters. It is designed as a prospector that would use a deep coring drill and apply soil analysis instruments to measure the abundance of elements of hydrogen and oxygen and other volatiles including water. Scarab’s chassis can adjust the wheelbase and height to stabilize its drill in contact with the ground and can also adjust posture to better ascend and descend steep slopes. This enables unique control of posture when moving and introduces new planning issues. Scarab has undergone field testing at Lunar-analog sites in Washington and Hawaii in an effort to quantify and validate its mobility and navigation capabilities. We report on results of the experiments in slope ascent and descent and in autonomous kilometer-distance navigation in darkness.

A photo-realistic 3-D mapping system for extreme nuclear environments: Chernobyl

We present a stereoscopic mapping system for use in post-nuclear accident operations by the Pioneer robot. First we discuss a radiation shielded sensor array designed to tolerate extended cumulative dose using 4/spl times/ shielding. Next, we outline procedures to ensure timely, accurate range estimation using trinocular stereo. Finally, we review the implementation of a system for the integration of range information into a 3-D, textured, metrically accurate surface mesh.

Comprehensive Automation for Specialty Crops: Year 1 results and lessons learned

Comprehensive Automation for Specialty Crops is a project focused on the needs of the specialty crops sector, with a focus on apples and nursery trees. The project’s main thrusts are the integration of robotics technology and plant science; understanding and overcoming socio-economic barriers to technology adoption; and making the results available to growers and stakeholders through a nationwide outreach program. In this article, we present the results obtained and lessons learned in the first year of the project with a reconfigurable mobility infrastructure for autonomous farm driving. We then present sensor systems developed to enable three real-world agricultural applications—insect monitoring, crop load scouting, and caliper measurement—and discuss how they can be deployed autonomously to yield increased production efficiency and reduced labor costs.

First experiment in sun-synchronous exploration

Sun-synchronous exploration is accomplished by reasoning about sunlight: where the Sun is in the sky, where and when shadows will fall, and how much power can be obtained through various courses of action. In July 2001 a solar-powered rover, named Hyperion, completed two sun-synchronous exploration experiments in the Canadian high arctic (75/spl deg/N). Using knowledge of orbital mechanics, local terrain, and expected power consumption, Hyperion planned a sun-synchronous route to visit designated sites while obtaining the necessary solar power for continuous 24-hour operation. Hyperion executed its plan and returned to its starting location with batteries fully charged after traveling more than 6 kilometers in barren, Mars-analog terrain. We describe the concept of sun-synchronous exploration. We overview the design of the robot Hyperion and the software system that enables it to operate sun-synchronously. We then discuss results from analysis of our first experiment in sun-synchronous exploration and conclude with observations.

Design and Experimentation of a Rover Concept for Lunar Crater Resource Survey

Scarab is a prospecting rover for lunar missions to survey resources, particularly water ice, in polar craters. It is designed for the deployment of a deep coring drill and for transport of soil analysis instruments. Its chassis can transform to stabilize the drill in contact with the ground and can also adjust to ascend and descent steep slopes of unconsolidated soil. Additional features include a compact body for better thermal regulation, laser scanners for dark navigation, and power system designed for a persistent, low-capacity source. Scarab was prototyped at the Robotics Institute, has undergone mobility testing in soils laboratories and field sites leading up to an integrated system test including the RESOLVE drill and instrument suite at the PISCES lunar analogue site on Mauna Kea in Hawaii.

Application of pulsed‐excitation fluorescence imager for daylight detection of sparse life in tests in the Atacama Desert

A daylight fluorescence imager was deployed on an autonomous rover, Zoe, to detect life on the surface and shallow subsurface in regions of the Atacama Desert in Chile during field tests between 2003 and 2005. In situ fluorescent measurements were acquired from naturally fluorescing biomolecules such as chlorophyll and from specific fluorescent probes sprayed on the samples, targeting each of the four biological macromolecule classes: DNA, protein, lipid, and carbohydrate. RGB context images were also acquired. Preparatory reagents were applied to enhance the dye probe penetration and fluorescence intensity of chlorophyll. Fluorescence imager data sets from 257 samples were returned to the Life in the Atacama science team. A variety of visible life forms, such as lichens, were detected, and several of the dye probes produced signals from nonphotosynthetic microorganisms.

Field Experiments in Mobility and Navigation with a Lunar Rover Prototype

Scarab is a prototype rover for lunar missions to survey resources, particularly water ice, in polar craters. It is designed as a prospector that would use a deep coring drill and apply soil analysis instruments. Its chassis can transform to stabilize its drill in contact with the ground and can also adjust posture to ascend and descent steep slopes. Scarab has undergone field testing at lunar analogue sites in Washington and Hawaii in an effort to quantify and validate its mobility and navigation capabilities. We report on results of experiments in slope ascent and descent and in autonomous kilometer-distance navigation in darkness.

Analysis of High-Efficiency Solar Cells in Mobile Robot Applications

This technical brief analyzes the performance of triple-junction solar cells on a mobile robot. Although originally designed for satellite use, it is demonstrated that triple-junction cells are effective in terrestrial applications. This makes them particularly suitable for systems with limited size and mass but high-power requirements such as a mobile robot. A testing station was specially constructed to characterize triple-junction and conventional silicon cell performance in different environments and to compare their effectiveness. Additional field tests were carried out with an autonomous robot in order to check the ability to deliver sufficient power to varying loads. Results show that they surpass conventional technologies with efficiencies higher than 22%, so they can be considered as an alternative technology for power sources on-board of terrestrial mobile robots.

Steering and control of a passively articulated robot

The need for light weight yet highly mobile robotic platforms is driven by the limitation of available power. With unlimited energy, surface exploration missions could survive for months or years and greatly exceed their current productivity. The Sun-Synchronous Navigation project is developing long-duration solar-powered robot exploration through research in planning techniques and low-mass robot configurations. Hyperion is a rover designed and built for experiments in sun-synchronous exploration. This paper details Hyperions steering mechanism and control, which features 4-wheel independent drive and an innovative passively articulated steering joint for locomotion.