Robust stereo ego-motion for long distance navigation Olson, C.F.; Matthies, L.H.; Schoppers, H. ...
Proceedings IEEE Conference on Computer Vision and Pattern Recognition. CVPR 2000 (Cat. No.PR00662),
2000, Volume:
2
Conference Proceeding
Several methods for computing observer motion from monocular and stereo image sequences have been proposed. However, accurate positioning over long distances requires a higher level of robustness ...than previously achieved. This paper describes several mechanisms for improving robustness in the context of a maximum-likelihood stereo ego-motion method. We demonstrate that even a robust system will accumulate super-linear error in the distance traveled due to increasing orientation errors. However, when an absolute orientation sensor is incorporated, the growth is reduced to linear in the distance traveled, grows much more slowly in practice. Our experiments, including a trial with 210 stereo pairs, indicate that these techniques can achieve errors below 1% of the distance traveled. This method has been implemented to run on-board a prototype Mars rover.
This paper presents the initial results of lander and rover localization and topographic mapping of the MER 2003 mission (by Sol 225 for Spirit and Sol 206 for Opportunity). The Spirit rover has ...traversed a distance of 3.2 km (actual distance traveled instead of odometry) and Opportunity
at 1.2 km. We localized the landers in the Gusev Crater and on the Meridiani Planum using two-way Doppler radio positioning technology and cartographic triangulations through landmarks visible in both orbital and ground images. Additional high-resolution orbital images were taken to verify
the determined lander positions. Visual odometry and bundleadjustment technologies were applied to overcome wheel slippages, azimuthal angle drift and other navigation errors (as large as 21 percent). We generated timely topographic products including 68 orthophoto maps and 3D Digital Terrain
Models, eight horizontal rover traverse maps, vertical traverse profiles up to Sol 214 for Spirit and Sol 62 for Opportunity, and five 3D crater models. A web-based landing-site Geographic Information System (GIS) has been set up at The Ohio State University to update and disseminate the daily
localization and topographic information to support tactical and strategic operations of the mission. Also described in this paper are applications of the data for science operations planning, geological traverse survey, survey of windrelated features, and other science applications. The majority
of the instruments onboard both rovers are healthy at this moment, and they will continue to explore the two landing sites on the Martian surface. We expect to report further localization and topographic mapping results to be achieved in the rest of the mission period and in post-mission data
processing.
NASA's Mars Science Laboratory (MSL) Curiosity rover landed on Mars on August 6, 2012. In the 7 years between landing and August 6, 2019 (sol 2488), Curiosity has driven 21,318.5 m over a variety of ...terrain types and slopes, employing multiple drive modes with varying amounts of onboard autonomy. Curiosity's drive distances each sol have ranged from its shortest drive of 2.6 cm to its longest drive of 142.5 m, with an average drive distance of 28.9 m. Real‐time human intervention is not possible during Curiosity's drives due to the latency in uplinking commands and downlinking telemetry. Instead, the operations team relies on Curiosity's fault protection, autonomous navigation, and visual odometry software to keep the rover safe during drives. During its first 7 years on Mars, Curiosity has attempted 738 drives. While 622 drives ran to completion, 116 drives were prevented or stopped early by Curiosity's fault protection software. The primary risks to mobility success have been wheel damage, wheel entrapment, progressive wheel sinkage, and the potential for hardware or cable failures that result in an inability to command one or more steer or drive actuators. In this paper, we describe Curiosity's mobility subsystem, mobility trends over the first 21.3 km of the mission, operational aspects of mobility fault protection, risks to continued mobility success, and risk mitigation strategies.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Spirit rover experienced significant slips traversing Husband Hill. This paper analyzes the slippage Spirit experienced from Sol 154 to Sol 737. Slippage with respect to terrain type and slope is ...computed using data downlinked from the rover, rover position, and orientation estimations from visual odometry (VO) and photogrammetry based bundle adjustment (BA) method. Accumulated slippage reached a maximum of 83.86 m on Sol 648. However, as Spirit descended into the Inner Basin, the direction of slippage reversed, and accumulated slippage approached zero by the end of the entire traverse. Eight local regions with significant slips and nineteen traverse segments have been analyzed. Slippage was found to be highly correlated to slope direction and magnitude; the reverse of slope directions in the ascending and descending portions of the traverse proves to be the main contributor to the observed cancellation of slippage. While the horizontal component of the slippage almost canceled out, the difference in elevation continually accumulated, mainly during the ascent. In general, long traverse segments created more slips than short ones. This is reflected in both the accumulated and individual slippages. In considering the four major Mars terrain types, Spirit performed best on bedrock, managing to drive on slopes close to 30°. Fine‐grain surfaces were the most challenging; though progress was made on slopes up to 15°, slippages of over 100% (more slippage than distance traveled) occurred for short segments. The results of this work can be incorporate into a traverse planning framework in which rover slippage is minimized. Results can be employed in landed planetary missions for precision navigation to avoid potentially dangerous regions by considering expected slippage.
Ground water resource management programs are paying increasing attention to the integration of ground water and surface water in the planning process. Many plans, however, show a sophistication in ...approach and presentation that masks a fundamental weakness in the overall analysis. The plans usually discuss issues of demand and yield, yet never directly address a fundamental issue behind the plan—how to define sustainable yield of an aquifer system. This paper points out a number of considerations that must be addressed in defining sustainable yield in order to make the definition more useful in practical water resource planning studies. These include consideration for the spatial and temporal aspects of the problem, the development of a conceptual water balance, the influence of boundaries and changes in technology on the definition, the need to examine water demand as well as available supply, the need for stakeholder involvement, and the issue of uncertainty in our understanding of the components of the hydrologic system.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
By sol 440, the Spirit rover has traversed a distance of 3.76 km (actual distance traveled instead of odometry). Localization of the lander and the rover along the traverse has been successfully ...performed at the Gusev crater landing site. We localized the lander in the Gusev crater using two‐way Doppler radio positioning and cartographic triangulations through landmarks visible in both orbital and ground images. Additional high‐resolution orbital images were used to verify the determined lander position. Visual odometry and bundle adjustment technologies were applied to compensate for wheel slippage, azimuthal angle drift, and other navigation errors (which were as large as 10.5% in the Husband Hill area). We generated topographic products, including 72 ortho maps and three‐dimensional (3‐D) digital terrain models, 11 horizontal and vertical traverse profiles, and one 3‐D crater model (up to sol 440). Also discussed in this paper are uses of the data for science operations planning, geological traverse surveys, surveys of wind‐related features, and other science applications.
This paper presents the results of Mars topographic mapping and lander and rover localization for the Opportunity rover at Meridiani Planum during the Mars Exploration Rover (MER) 2003 mission. By ...Sol 458, the Opportunity rover traversed a distance of 5.20 km. We localized the lander using two‐way Doppler radio positioning and cartographic triangulation of craters visible in both orbital and ground images. Additional high‐resolution orbital images were taken to verify the determined lander position. Visual odometry and bundle adjustment techniques were applied to overcome wheel slippages, azimuthal angle drift, and other navigation errors (as large as 21% within Eagle crater). In addition, orbit‐to‐ground image‐based adjustment was applied to correct rover location errors where bundle adjustment was not applicable. We generated timely topographic products, including orthoimages, digital terrain models (DTMs), three‐dimensional (3‐D) crater models, and rover traverse maps. In particular, detailed 3‐D terrain models of major features, such as Endurance crater, have been generated using multisite panoramic stereo images based on bundle adjustment and wide baseline stereo technique.
The Mars Science Laboratory (MSL) Curiosity rover is about to receive its sixth and likely final complete flight software update after having operated on Mars for more than a decade. Software ...transitions on MSL provide an opportunity to add or replace functionality, fix bugs, and prepare for future capabilities. The penultimate full software release, R12, was installed on Curiosity in 2015, three years after its August 2012 landing, and was followed over the subsequent seven years by many patches as engineers worked to address new mission constraints quickly. Because each additional patch increases the complexity of maintaining and operating the rover, a new flight software update called R13 was proposed, which aimed to make operations more straightforward by incorporating existing patches, improved software capabilities, and new software capabilities into a single monolithic rover flight software image. The R13 development effort kicked off in early 2017. Over the next six years, the scope of R13 expanded to include many desired capabilities and bug fixes - some of which were proposed even earlier than 2015 but were unable to be implemented in R12. Overall, the MSL Change Control Board approved 56 bug fixes and 53 new features for R13 development. Twenty-seven developers implemented these changes over a 3.5-year period. Following a 2.25-year testing campaign, R13 was approved for use in flight onboard Curiosity. In this paper, we detail the path of the R13 flight software release from its proposal in April 2016 to its approval for use in flight in September 2022.
In this paper, visual odometry is presented as an approach to position estimation to find features in a stereo image pair and track them from one frame to the next. Visual odometry has been a highly ...effective tool for maintaining vehicle safety while driving near obstacles on slopes, achieving difficult drive approaches in fewer sols, and ensuring accurate science imaging. Although it requires active pointing by human drivers in feature-poor terrain, the improved position knowledge enables more autonomous capability and better science return during planetary operations
After landing in Gale Crater on August 6, 2012, the Mars Science Laboratory Curiosity rover traveled across regolith‐covered, rock‐strewn plains that transitioned into terrains that have been ...variably eroded, with valleys partially filled with windblown sands, and intervening plateaus capped by well‐cemented sandstones that have been fractured and shaped by wind into outcrops with numerous sharp rock surfaces. Wheel punctures and tears caused by sharp rocks while traversing the plateaus led to directing the rover to traverse in valleys where sands would cushion wheel loads. This required driving across a megaripple (windblown, sand‐sized deposit covered by coarser grains) that straddles a narrow gap and several extensive megaripple deposits that accumulated in low portions of valleys. Traverses across megaripple deposits led to mobility difficulties, with sinkage values up to approximately 30% of the 0.50 m wheel diameter, resultant high compaction resistances, and rover‐based slip up to 77%. Analysis of imaging and engineering data collected during traverses across megaripples for the first 710 sols (Mars days) of the mission, laboratory‐based single‐wheel soil experiments, full‐scale rover tests at the Dumont Dunes, Mojave Desert, California, and numerical simulations show that a combination of material properties and megaripple geometries explain the high wheel sinkage and slip events. Extensive megaripple deposits have subsequently been avoided and instead traverses have been implemented across terrains covered with regolith or thin windblown sand covers and megaripples separated by bedrock exposures.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
PDF
