Planetary micro-rover operations on Mars using a Bayesian framework for inference and control

With the recent progress toward the application of commercially-available hardware to small-scale space missions, it is now becoming feasible for groups of small, efficient robots based on low-power embedded hardware to perform simple tasks on other planets in the place of large-scale, heavy and expensive robots. In this paper, we describe design and programming of the Beaver micro-rover developed for Northern Light, a Canadian initiative to send a small lander and rover to Mars to study the Martian surface and subsurface. For a small, hardware-limited rover to handle an uncertain and mostly unknown environment without constant management by human operators, we use a Bayesian network of discrete random variables as an abstraction of expert knowledge about the rover and its environment, and inference operations for control. A framework for efficient construction and inference into a Bayesian network using only the C language and fixed-point mathematics on embedded hardware has been developed for the Beaver to make intelligent decisions with minimal sensor data. We study the performance of the Beaver as it probabilistically maps a simple outdoor environment with sensor models that include uncertainty. Results indicate that the Beaver and other small and simple robotic platforms can make use of a Bayesian network to make intelligent decisions in uncertain planetary environments

Autonomous navigation with ROS for a mobile robot in agricultural fields

Autonomous monitoring of agricultural farms and fields has recently become feasible due to continuing advances in robotics technology, but many notable challenges remain. In this paper, we describe the state of ongoing work to create a fully autonomous ground rover platform for monitoring and intervention tasks on modern farms that is built using inexpensive and off the shelf hardware and Robot Operating System (ROS) software so as to be affordable to farmers. The hardware and software architectures used in this rover are described along with challenges and solutions in odometry and localization, object recognition and mapping, and path planning algorithms under the constraints of the current hardware. Results obtained from laboratory and field testing show both the key challenges to be overcome, and the current successes in applying a low-cost rover platform to the task of autonomously navigating the outdoor farming environment

The language codes of ISO 639: A premature, ultimately unobtainable, and possibly damaging standardization

009 Stephen Morey, Mark W. Post and Victor Friedman The language codes of ISO 639: A premature and possibly unobtainable standardization ISO 639 is an ambitious attempt to standardize and organize various types of references to the languages of the world. It is designed to be fully comprehensive and permanent; as such, it promises to greatly enhance the precision and reliability with which language materials can be archived, catalogued, and referenced in the literature, as well as the ease and precision with which such materials and references can be processed by machines and effectively located via search queries. There are, however, a number of serious problems with several components of ISO 639 as they are currently conceived. At a minimum, these are: (1) use of both The Ethnologue as the basis for ISO 639-3’s “three-letter codes” and of SIL as its registration authority is problematic for a number of reasons (2) in-principle “arbitrary” (but in fact not arbitrary) “mnemonic” labels of ISO 639-3 have the potential to enshrine offensive designations for language communities, and in fact currently do so (3) decision-making processes in ISO 639-3 are currently excessively centralized and privilege the views of a minority of the linguistics community (4) the in-principle “permanency” of language codes such as those of ISO 639-3 is fundamentally incompatible with the nature of human languages, which are demonstrably impermanent (5) the structure of ISO 639-3 has a serious potential to be misunderstood, misused, and in fact abused by decision-making bodies (such as arms of government in various political contexts) (6) ISO 639-5, which attempts to catalogue the genetic affiliations of the world’s languages, is highly premature, since there is nothing approaching agreement among specialists in a great number of cases (7) ISO 639-6, which attempts to catalogue language variation, is in principle impossible, unless it aims to extend to an analysis of the language use of every human being on Earth, living or dead On the basis of these observations, which we will illustrate by means of three detailed “case studies” from the Eastern Himalaya, the Burmese/Indian border region, and the Balkan region, we will argue that ISO 639 must be substantially re-conceived and re-organized before it can be supported by linguists. The language codes of ISO 639: A premature and possibly unobtainable standardization. ISO 639 is an ambitious attempt to standardize and organize various types of references to the languages of the world. It is designed to be fully comprehensive and permanent; as such, it promises to greatly enhance the precision and reliability with which language materials can be archived, catalogued, and referenced in the literature, as well as the ease and precision with which such materials and references can be processed by machines and effectively located via search queries. There are, however, a number of serious problems with several components of ISO 639 as they are currently conceived. At a minimum, these are: (1) use of both The Ethnologue as the basis for ISO 639-3’s “three-letter codes” and of SIL as its registration authority is problematic for a number of reasons (2) in-principle “arbitrary” (but in fact not arbitrary) “mnemonic” labels of ISO 639-3 have the potential to enshrine offensive designations for language communities, and in fact currently do so (3) decision-making processes in ISO 639-3 are currently excessively centralized and privilege the views of a minority of the linguistics community (4) the in-principle “permanency” of language codes such as those of ISO 639-3 is fundamentally incompatible with the nature of human languages, which are demonstrably impermanent (5) the structure of ISO 639-3 has a serious potential to be misunderstood, misused, and in fact abused by decision-making bodies (such as arms of government in various political contexts) (6) ISO 639-5, which attempts to catalogue the genetic affiliations of the world’s languages, is highly premature, since there is nothing approaching agreement among specialists in a great number of cases (7) ISO 639-6, which attempts to catalogue language variation, is in principle impossible, unless it aims to extend to an analysis of the language use of every human being on Earth, living or dead On the basis of these observations, which we will illustrate by means of three detailed “case studies” from the Eastern Himalaya, the Burmese/Indian border region, and the Balkan region, we will argue that ISO 639 must be substantially re-conceived and re-organized before it can be supported by linguists

Visual pose estimation system for autonomous rendezvous of spacecraft

In this work, a tracker spacecraft equipped with a short-range vision system is tasked with visually identifying a target spacecraft and determining its relative angular velocity and relative linear velocity using only visual information from onboard cameras. Focusing on methods that are feasible for implementation on relatively simple spacecraft hardware, we locate and track objects in three-dimensional space using conventional high-resolution cameras, saving cost and power compared to laser or infrared ranging systems. Identification of the target is done by means of visual feature detection and tracking across rapid, successive frames, taking the perspective matrix of the camera system into account, and building feature maps in three dimensions over time. Features detected in two-dimensional images are matched and triangulated to provide three-dimensional feature maps using structure-from-motion techniques. This methodology allows one, two, or more cameras with known baselines to be used for triangulation, with more images resulting in higher accuracy. Triangulated points are organized by means of orientation histogram descriptors and used to identify and track parts of the target spacecraft over time. This allows some estimation of the target spacecraft's motion even if parts of the spacecraft are obscured or in shadow. The state variables with respect to the camera system are extracted as a relative rotation quaternion and relative translation vector for the target. Robust tracking of the state variables for the target spacecraft is accomplished by an embedded adaptive unscented Kalman filter. In addition to estimation of the target quaternion from visual Information, the adaptive filter can also identify when tracking errors have occurred by measurement of the residual. Significant variations in lighting can be tolerated as long as the movement of the satellite is consistent with the system model, and illumination changes slowly enough for state variables to be estimated periodically. Inertial measurements over short periods of time can then be used to determine the movement of both the tracker and target spacecraft. In addition, with a sufficient number of features tracked, the center of mass of the target can be located. This method is tested using laboratory images of spacecraft movement with a simulated spacecraft movement model. Varying conditions are applied to demonstrate the effectiveness and limitations of the system for online estimation of the movement of a target spacecraft at close range

3D LiDAR Scanning of Urban Forest Structure Using a Consumer Tablet

Forest measurements using conventional methods may not capture all the important information required to properly characterize forest structure. The objective of this study was to develop a low-cost alternative method for forest inventory measurements and characterization of forest structure using handheld LiDAR technology. Three-dimensional (3D) maps of trees were obtained using an iPad Pro with a LiDAR sensor. Freely-available software programs, including 3D Forest Software and CloudCompare software, were used to determine tree diameter at breast height (DBH) and distance between trees. The 3D point cloud data obtained from the iPad Pro LiDAR sensor was able to estimate tree DBH accurately, with a residual error of 2.4 cm in an urban forest stand and 1.9 cm in an actively managed experimental forest stand. Distances between trees also were accurately estimated, with mean residual errors of 0.21 m for urban forest, and 0.38 m for managed forest stand. This study demonstrates that it is possible to use a low-cost consumer tablet with a LiDAR sensor to accurately measure certain forest attributes, which could enable the crowdsourcing of urban and other forest tree DBH and density data because of its integration into existing Apple devices and ease of use

Fast Radiometric Compensation for Nonlinear Projectors

Radiometric compensation can be accomplished on nonlinearprojector-camera systems through the use of pixelwise lookup ta-bles. Existing methods are both computationally and memory inten-sive. Such methods are impractical to be implemented for currenthigh-end projector technology. In this paper, a novel computation-ally efficient method for nonlinear radiometric compensation of pro-jectors is proposed. The compensation accuracy of the proposedmethod is assessed with the use of a spectroradiometer. Experi-mental results show both the effectiveness of the method and thereduction in compensation time compared to a recent state-of-the-art method

Constraints for Time-Multiplexed Structured Light with a Hand-held Camera

Multi-frame structured light in projector-camera systems affords high-density and non-contact methods of 3D surface reconstruction. However, they have strict setup constraints which can become expensive and time-consuming. Here, we investigate the conditions under which a projective homography can be used to compensate for small perturbations in pose caused by a hand-held camera. We synthesize data using a pinhole camera model and use it to determine the average 2D reprojection error per point correspondence. This error map is grouped into regions with specified upper-bounds to classify which regions produce sufficiently minimal error to be considered feasible for a structured-light projector-camera system with a hand-held camera. Empirical results demonstrate that a sub-pixel reprojection accuracy is achievable with a feasible geometric constraint

Climate Change Planning: Soil Carbon Regulating Ecosystem Services and Land Cover Change Analysis to Inform Disclosures for the State of Rhode Island, USA

The state of Rhode Island (RI) has established its greenhouse gas (GHG) emissions reduction goals, which require rapidly acquired and updatable science-based data to make these goals enforceable and effective. The combination of remote sensing and soil information data can estimate the past and model future GHG emissions because of conversion of “low disturbance” land covers (e.g., evergreen forest, hay/pasture) to “high disturbance” land covers (e.g., low-, medium-, and high-intensity developed land). These modeled future emissions can be used as a predevelopment potential GHG emissions information disclosure. This study demonstrates the rapid assessment of the value of regulating ecosystems services (ES) from soil organic carbon (SOC), soil inorganic carbon (SIC), and total soil carbon (TSC) stocks, based on the concept of the avoided social cost of carbon dioxide (CO2) emissions for RI by soil order and county using remote sensing and information from the State Soil Geographic (STATSGO) and Soil Survey Geographic Database (SSURGO) databases. Classified land cover data for 2001 and 2016 were downloaded from the Multi-Resolution Land Characteristics Consortium (MRLC) website. Obtained results provide accurate and quantitative spatio-temporal information about likely GHG emissions and show their patterns which are often associated with existing urban developments. These remote sensing tools could be used by the state of RI to both understand the nature of land cover change and likely GHG emissions from soil and to institute mandatory or voluntary predevelopment assessments and potential GHG emissions disclosures as a part of a climate mitigation policy

Quantifying Damages to Soil Health and Emissions from Land Development in the State of Illinois (USA)

The concept of soil health is increasingly being used as an indicator for sustainable soil management and even includes legislative actions. Current applications of soil health often lack geospatial and monetary analyses of damages (e.g., land development), which can degrade soil health through loss of carbon (C) and productive soils. This study aims to evaluate the damages to soil health (e.g., soil C, the primary soil health indicator) attributed to land developments within the state of Illinois (IL) in the United States of America (USA). All land developments in IL can be associated with damages to soil health, with 13,361.0 km2 developed, resulting in midpoint losses of 2.5 × 1011 of total soil carbon (TSC) and a midpoint social cost of carbon dioxide emissions (SC-CO2) of $41.8B (where B = billion = 109, USD). More recently developed land area (721.8 km2) between 2001 and 2016 likely caused the midpoint loss of 1.6 × 1010 kg of TSC and a corresponding midpoint of$2.7B in SC-CO2. New developments occurred adjacent to current urban areas near the capital cities of Springfield, Chicago, and St. Louis (the border city between the states of Missouri and IL). Results of this study reveal several types of damage to soil health from developments: soil C loss, associated “realized” soil C social costs (SC-CO2), and loss of soil C sequestration potential from developments. The innovation of this study has several aspects. Geospatial analysis of land cover combined with corresponding soil types can identify changes in the soil health continuum at the landscape level. Because soil C is a primary soil health indicator, land conversions caused by developments reduce soil health and the availability of productive soils for agriculture, forestry, and C sequestration. Current IL soil health legislation can benefit from this landscape level data on soil C loss with GHG emissions and associated SC-CO2 costs by providing insight into the soil health continuum and its dynamics. These techniques and data can also be used to expand IL’s GHG emissions reduction efforts from being solely focused on the energy sector to include soil-based emissions from developments. Current soil health legislation does not recognize that soil’s health is harmed by disturbance from land developments and that this disturbance results in GHG emissions. Soil health programs could be broadened to encourage less disturbance of soil types that release high levels of GHG and set binding targets based on losses in the soil health continuum

How body balance influences political party evaluations: A wii balance board study

Embodied cognition research has shown how actions or body positions may affect cognitive processes, such as autobiographical memory retrieval or judgments. The present study examined the role of body balance (to the left or the right) in participants on their attributions to political parties. Participants thought they stood upright on aWii™ Balance Board, while they were actually slightly tilted to the left or the right. Participants then ascribed fairly general political statements to one of 10 political parties that are represented in the Dutch House of Representatives. Results showed a significant interaction of congruent leaning direction with left-or right-wing party attribution. When the same analyses were performed with the political parties being divided into affiliations to the right, center, and left based on participants' personal opinions rather than a ruling classification, no effects were found. The study provides evidence that conceptual metaphors are activated by manipulating body balance implicitly. Moreover, people's judgments may be colored by seemingly trivial circumstances such as standing slightly out of balance