Aerial-Ground collaborative sensing: Third-Person view for teleoperation

Rapid deployment and operation are key requirements in time critical application, such as Search and Rescue (SaR). Efficiently teleoperated ground robots can support first-responders in such situations. However, first-person view teleoperation is sub-optimal in difficult terrains, while a third-person perspective can drastically increase teleoperation performance. Here, we propose a Micro Aerial Vehicle (MAV)-based system that can autonomously provide third-person perspective to ground robots. While our approach is based on local visual servoing, it further leverages the global localization of several ground robots to seamlessly transfer between these ground robots in GPS-denied environments. Therewith one MAV can support multiple ground robots on a demand basis. Furthermore, our system enables different visual detection regimes, and enhanced operability, and return-home functionality. We evaluate our system in real-world SaR scenarios.Comment: Accepted for publication in 2018 IEEE International Symposium on Safety, Security and Rescue Robotics (SSRR

Forklift Routing in Warehouses Using Dual-Commands and Stackable Pallets

This research determines time optimal routes for loading and picking pallets that can be stacked on top of each other during transport in a manual warehouse that only contains full pallets and utilizes single deep storage. This research was motivated by the fact that we are seeing this situation on an ever increasing basis, particularly in warehouses that supply parts to automotive assembly. In practice, forklift drivers have developed strategies to take advantage of this opportunity but to our knowledge there is no literature that addresses this problem rigorously. The important features of this work are that a time based mathematical model is required because the time spent stacking and unstacking pallets can be significant and a modeling approach to including stacking had to be developed. The basic models are included here with examples and insights into future work required for applicability to a wider range of users

Design & Modeling of a Single Machine Flow Rack As/rs

In this paper, we aim to introduce a new variation of the flow rack automated storage and retrieval system (AS/RS) using a single machine for storage and retrieval operations instead of two machines. Also, analytical expressions are derived for expected single and dual cycle times of the storage and retrieval machine. For that, randomized storage assignment, and Tchebychev travel are assumed. Two dwell point positions are investigated and compared to determine the best one. Finally an experimental validation using simulation is conducted to verify the quality of the developed

Investigation of Radar Subsurface Sounding through Seasonal Cycles Collected by Mars Shallow Radar (SHARAD) in the South Polar Area

Using an orbital-based ground-penetrating radar - SHARAD proves to be an effective method for imaging the Martian surface and subsurface layering at the south polar layered deposit. This investigation focuses on examining whether seasonal variation of CO2 thickness on the surface caused by accumulation during winter and sublimation during summer could be observed for the first time by analyzing SHARAD data. Travel time and amplitude analysis between the Martian surface reflection and a reference reflection in the subsurface were conducted on multiple orbital tracks corresponding to varying seasons. Results from the travel time analysis along all four cross-lines show that the average change in CO2 frost thickness ranged from 6.80 m to 9.58 m assuming a medium dielectric constant between 2.12 and 2.77. The CO2 thickness reaches its maximum during winter and minimum during summer likely because of the CO2 frost accumulation and retreat, respectively. This observation agrees with other studies. However, the magnitude of change in CO2 thickness estimated in this study is greater than values reported previously. This difference is attributed to the different locations of the Martian polar region examined in the various studies. Amplitude analysis does not show any relationship to seasonal variations on the Martian surface

Distribution Planning Considering Warehousing Decisions

Modern supply chains heavily depend on warehouses for rapidly fulfilling customer demands through retail, web-based, and catalogue channels. The traditional approach that considers warehouses as cost-centers has affected the profitability of numerous supply chains. A lack of synchronization between procurement and allocation decisions causes warehouses to scramble for resources during peak times and be faced with under-utilized resources during drought times. Warehouses, however, have emerged as service-centers and it is imperative that warehousing decisions be an integral part of supply chain decisions. In this paper we propose a mixed-integer programming model to integrate warehousing decisions with those of inventory and transportation to minimize long-run distribution cost. Preliminary experiments suggest a sizeable reduction in the level and variance in the warehouse workforce requirements. A cost savings ranging between 2-6% is also realized

Urban Air Mobility Market Study

The Booz Allen Team explored market size and potential barriers to Urban Air Mobility (UAM) by focusing on three potential markets – Airport Shuttle, Air Taxi, and Air Ambulance. We found that the Airport Shuttle and Air Taxi markets are viable, with a significant total available market value in the U.S. of $500 billion, for a fully unconstrained scenario. In this unconstrained best-case scenario, passengers would have the ability to access and fly a UAM at any time, from any location to any destination, without being hindered by constraints such as weather, infrastructure, or traffic volume. Significant legal and regulatory, weather, certification, public perception, and infrastructure constraints exist, which reduce the market potential for these applications to only about 0.5$2.5 billion, in the near term. However, we determined that these constraints can be addressed through ongoing intra-governmental partnerships, government and industry collaboration, strong industry commitment, and existing legal and regulatory enablers. We found that the Air Ambulance market is not a viable market if served by electric vertical takeoff and landing (eVTOL) vehicles due to technology constraints but may potentially be viable if a hybrid VTOL aircraft are utilized

Implosion in the Challenger Deep: echo sounding with the shock wave

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Loranger, S., Barclay, D., & Buckingham, M. Implosion in the Challenger Deep: echo sounding with the shock wave. Oceanography, 34(2), (2021), https://doi.org/10.5670/oceanog.2021.201.Since HMS Challenger made the first sounding in the Mariana Trench in 1875, scientists and explorers have been seeking to establish the exact location and depth of the deepest part of the ocean. The scientific consensus is that the deepest depth is situated in the Challenger Deep, an abyss in the Mariana Trench with depths greater than 10,000 m. Since1952, when HMS Challenger II, following its namesake, returned to the Mariana Trench, 20 estimates (including the one from this study) of the depth of the Challenger Deep have been made. The location and depth estimates are as diverse as the methods used to obtain them; they range from early measurements with explosives and stopwatches, to single- and multibeam sonars, to submersibles, both crewed and remotely operated. In December 2014, we participated in an expedition to the Challenger Deep onboard Schmidt Ocean Institute’s R/V Falkor and deployed two free-falling, passive-acoustic instrument platforms, each with a glass-sphere pressure housing containing system electronics. At a nominal depth of 9,000 m, one of these housings imploded, creating a highly energetic shock wave that, as recorded by the other instrument, reflected multiple times from the sea surface and seafloor. From the arrival times of these multi-path pulses at the surviving instrument, in conjunction with a concurrent measurement of the sound speed profile in the water column, we obtained a highly constrained acoustic estimate of the Challenger Deep: 10,983 ± 6 m.This work was funded by the Schmidt Ocean Institute, the Ocean Frontiers Institute, and the Office of Naval Research, Ocean Acoustics, Code 322OA, grant number N00014-18-1-2126