Kurt Schwehr

Virtual Reality Interfaces for Visualization and Control of Remote Vehicles

The Autonomy and Robotics Area (ARA) at NASA Ames Research Center has investigated the use of various types of Virtual Reality-based operator interfaces to remotely control complex robotic mechanisms. In this paper, we describe the major accomplishments and technology applications of the ARA in this area, and highlight the advantages and issues related to this technology.

Characterization of soft-sediment deformation: Detection of cryptoslumps using magnetic methods

Many workers have explored anisotropy of magnetic susceptibility (AMS) of sediments as an indicator of deformation. Several studies have used deflection of the eigenvector associated with the minimum in susceptibility, V3, as a criterion for deformation. We examine the AMS record of a well-exposed slump and find that although demonstrable deformation can occur without deflecting the V 3 directions, an oblate AMS fabric is transformed into a triaxial fabric during initial deformation. Transformation of the fabric from oblate to triaxial appears to be highly correlated with an increase in natural remanent magnetization scatter, whereas deflection of the V 3 axes is not. We suggest that subtle soft-sediment deformation can be detected by using AMS fabric.

Operating Nomad during the Atacama Desert Trek

Nomad is a mobile robot designed for extended planetary exploration. In June and July of 1997, Nomad performed the first such mission, traversing more than 220 kilometers in the Atacama Desert of Chile and exploring a landscape analogous to that of the Moon and Mars. Nomads journey, the Atacama Desert Trek, was an unprecedented demonstration of long-distance, long-duration robotic operation. Guided by operators thousands of kilometers away but telepresent via immersive imagery and interfaces, Nomad operated continuously for 45 days. Science field experiments evaluated exploration strategies and analysis techniques for future terrestrial and planetary missions.

Self-Positioning Smart Buoys, The "Un-Buoy" Solution: Logistic Considerations using Autonomous Surface Craft Technology and Improved Communications Infrastructure

Moored buoys have long served national interests, but incur high development, construction, installation, and maintenance costs. Buoys which drift off-location can pose hazards to mariners, and in coastal waters may cause environmental damage. Moreover, retrieval, repair and replacement of drifting buoys may be delayed when data would be most useful. Such gaps in coastal buoy data can pose a threat to national security by reducing maritime domain awareness. The concept of self-positioning buoys has been advanced to reduce installation cost by eliminating mooring hardware. We here describe technology for operation of reduced cost self-positioning buoys which can be used in coastal or oceanic waters. The ASC SCOUT model is based on a self-propelled, GPS-positioned, autonomous surface craft that can be pre-programmed, autonomous, or directed in real time. Each vessel can communicate wirelessly with deployment vessels and other similar buoys directly or via satellite. Engineering options for short or longer term power requirements are considered, in addition to future options for improved energy delivery systems. Methods of reducing buoy drift and position-maintaining energy requirements for self-locating buoys are also discussed, based on the potential of incorporating traditional maritime solutions to these problems. We here include discussion of the advanced Delay Tolerant Networking (DTN) communications draft protocol which offers improved wireless communication capabilities underwater, to adjacent vessels, and to satellites. DTN is particularly adapted for noisy or loss-prone environments, thus it improves reliability. In addition to existing buoy communication via commercial satellites, a growing network of small satellites known as PICOSATs can be readily adapted to provide low-cost communications nodes for buoys. Coordination with planned vessel Automated Identification Systems (AIS) and International Maritime Organization standards for buoy and vessel notification systems are reviewed and the legal framework for deployment of autonomous surface vessels is considered

Field Experiments with the Ames Marsokhod Rover

In an ongoing series of field experiments, the Ames Marsokhod rover is deployed to remote locations and operated by scientists in simulated planetary explorations. These experiments provide insight both for scientists preparing for real planetary surface exploration and for robotics researchers. In this paper we will provide an overview of our work with the Marsokhod, describe the various subsystems that have been developed, discuss the latest in a series of field experiments, and discuss the lessons learned about performing remote geology.

Detecting compaction disequilibrium with anisotropy of magnetic susceptibility

In clay-rich sediment, microstructures and macrostructures influence how sediments deform when under stress. When lithology is fairly constant, anisotropy of magnetic susceptibility (AMS) can be a simple technique for measuring the relative consolidation state of sediment, which reflects the sediment burial history. AMS can reveal areas of high water content and apparent overconsolidation associated with unconformities where sediment overburden has been removed. Many other methods for testing consolidation and water content are destructive and invasive, whereas AMS provides a nondestructive means to focus on areas for additional geotechnical study. In zones where the magnetic minerals are undergoing diagenesis, AMS should not be used for detecting compaction state. By utilizing AMS in the Santa Barbara Basin, we were able to identify one clear unconformity and eight zones of high water content in three cores. With the addition of susceptibility, anhysteretic remanent magnetization, and isothermal remanent magnetization rock magnetic techniques, we excluded 3 out of 11 zones from being compaction disequilibria. The AMS signals for these three zones are the result of diagenesis, coring deformation, and burrows. In addition, using AMS eigenvectors, we are able to accurately show the direction of maximum compression for the accumulation zone of the Gaviota Slide.

Visualization tools facilitate geological investigations of Mars Exploration Rover landing sites

The current rate of Mars exploration data acquisition demands that geoscientists and computer scientists coordinate central storage, processing and visualization strategies to anticipate future technological advancements. We investigate how existing 3-D visualization tools can be used to study a part of the Mars orbiter and lander data (about 4 terabytes of data). Our tools assist in juxtaposition of different datum and in viewing data that spans multiple orders of magnitude, specifically for current scientific research pertaining to Mars’ geophysics and geology. These tools also permit effective data fidelity and resolution assessment, allowing quick identification of problems related to the use of differing spatial coordinate systems, a continued problem. Knowledge gained from the small dataset we test, helps us identify key tools needed to accommodate the technology required to process and analyze approximately 64 terabytes of Mars data expected by 2008. We use the current planetary data archives, and identify key visualization techniques and tools that distill multiple data types into manageable end products. Our goal is to broaden the user base, using readily available platform-independent freeware packages, while simultaneously including sufficient modularity to be compatible with future technologies.

Characterizing the relative contributions of large vessels to total ocean noise fields: a case study using the Gerry E. Studds Stellwagen Bank National Marine Sanctuary

Understanding and mitigating the effects of underwater noise on marine species requires substantial information regarding acoustic contributions from shipping. In 2006, we used the U.S. Coast Guards Automatic Identification System (AIS) to describe patterns of large commercial ship traffic within a U.S. National Marine Sanctuary. AIS data were combined with low‐frequency acoustic data from an array of nine‐ten autonomous recording units deployed throughout 2006. Analysis of received sound levels (10‐1000 Hz, root‐mean squared decibels re 1 μPascal ± standard error) averaged 119.5 ± 0.3 at high traffic locations. High traffic locations experienced double the acoustic power of less trafficked locations for the majority of the time period analyzed. Average source level estimates (71‐141 Hz, root‐mean squared decibels re 1 μPascal ± standard error) for individual vessels ranged from 158 ± 2 (research vessel) to 186 ± 2 (oil tanker). Tankers were estimated to contribute two times more acoustic power to the re...

Designing visualization software for ships and robotic vehicles

One of the challenges of visualization software design is providing real-time tools capable of concurrently displaying data that varies temporally and in scale from kilometers to micrometers, such as the data prevalent in planetary exploration and deep-sea marine research. The Viz software developed by NASA Ames and the additions of the X-Core extensions solve this problem by providing a flexible framework for rapidly developing visualization software capable of accessing and displaying large dynamic data sets. This paper describes the Viz/X-Core design and illustrates the operation of both systems over a number of deployments ranging from marine research to Martian exploration. Highlights include a 2002 integration with live ship operations and the Mars Exploration Rovers Spirit and Opportunity.