Space time neural networks for tether operations in space

A space shuttle flight scheduled for 1992 will attempt to prove the feasibility of operating tethered payloads in earth orbit. due to the interaction between the Earth's magnetic field and current pulsing through the tether, the tethered system may exhibit a circular transverse oscillation referred to as the 'skiprope' phenomenon. Effective damping of skiprope motion depends on rapid and accurate detection of skiprope magnitude and phase. Because of non-linear dynamic coupling, the satellite attitude behavior has characteristic oscillations during the skiprope motion. Since the satellite attitude motion has many other perturbations, the relationship between the skiprope parameters and attitude time history is very involved and non-linear. We propose a Space-Time Neural Network implementation for filtering satellite rate gyro data to rapidly detect and predict skiprope magnitude and phase. Training and testing of the skiprope detection system will be performed using a validated Orbital Operations Simulator and Space-Time Neural Network software developed in the Software Technology Branch at NASA's Lyndon B. Johnson Space Center

Tethers in space handbook

The handbook provides a list and description of ongoing tether programs. This includes the joint U.S.-Italy demonstration project, and individual U.S. and Italian studies and demonstration programs. An overview of the current activity level and areas of emphasis in this emerging field is provided. The fundamental physical principles behind the proposed tether applications are addressed. Four basic concepts of gravity gradient, rotation, momentum exchange, and electrodynamics are discussed. Information extracted from literature, which supplements and enhances the tether applications is also presented. A bibliography is appended

Event-based Vision: A Survey

Event cameras are bio-inspired sensors that differ from conventional frame cameras: Instead of capturing images at a fixed rate, they asynchronously measure per-pixel brightness changes, and output a stream of events that encode the time, location and sign of the brightness changes. Event cameras offer attractive properties compared to traditional cameras: high temporal resolution (in the order of microseconds), very high dynamic range (140 dB vs. 60 dB), low power consumption, and high pixel bandwidth (on the order of kHz) resulting in reduced motion blur. Hence, event cameras have a large potential for robotics and computer vision in challenging scenarios for traditional cameras, such as low-latency, high speed, and high dynamic range. However, novel methods are required to process the unconventional output of these sensors in order to unlock their potential. This paper provides a comprehensive overview of the emerging field of event-based vision, with a focus on the applications and the algorithms developed to unlock the outstanding properties of event cameras. We present event cameras from their working principle, the actual sensors that are available and the tasks that they have been used for, from low-level vision (feature detection and tracking, optic flow, etc.) to high-level vision (reconstruction, segmentation, recognition). We also discuss the techniques developed to process events, including learning-based techniques, as well as specialized processors for these novel sensors, such as spiking neural networks. Additionally, we highlight the challenges that remain to be tackled and the opportunities that lie ahead in the search for a more efficient, bio-inspired way for machines to perceive and interact with the world

Evaluation of the Terminal Sequencing and Spacing System for Performance Based Navigation Arrivals

NASA has developed the Terminal Sequencing and Spacing (TSS) system, a suite of advanced arrival management technologies combining timebased scheduling and controller precision spacing tools. TSS is a ground-based controller automation tool that facilitates sequencing and merging arrivals that have both current standard ATC routes and terminal Performance-Based Navigation (PBN) routes, especially during highly congested demand periods. In collaboration with the FAA and MITRE's Center for Advanced Aviation System Development (CAASD), TSS system performance was evaluated in human-in-the-loop (HITL) simulations with currently active controllers as participants. Traffic scenarios had mixed Area Navigation (RNAV) and Required Navigation Performance (RNP) equipage, where the more advanced RNP-equipped aircraft had preferential treatment with a shorter approach option. Simulation results indicate the TSS system achieved benefits by enabling PBN, while maintaining high throughput rates-10% above baseline demand levels. Flight path predictability improved, where path deviation was reduced by 2 NM on average and variance in the downwind leg length was 75% less. Arrivals flew more fuel-efficient descents for longer, spending an average of 39 seconds less in step-down level altitude segments. Self-reported controller workload was reduced, with statistically significant differences at the p less than 0.01 level. The RNP-equipped arrivals were also able to more frequently capitalize on the benefits of being "Best-Equipped, Best- Served" (BEBS), where less vectoring was needed and nearly all RNP approaches were conducted without interruption

Trailer Reverse Assist. Optical Follow Me

Backing-up a trailer is a difficult task even for experienced users, and thus, solutions exist for assisting the steering of a vehicle-trailer system by just requiring the input of the desired trailer’s trajectory. Nevertheless, the problem is not entirely solved as the selected trajectory clearance while reversing a trailer is not completely available due to visibility obstructions, making reversing a trailer an unsafe maneuver. The objective of this work is to perform a proof-of-concept of a system which aids the user in the process of backing up a trailer through the desired trajectory where limited visibility is present. This was accomplished by developing an add-on feature capable of tracking a helping person. The new feature provides the required information so that existing compatible trailer reversing solutions can steer and accelerate the vehicle to follow the tracked person while also keeping a safe distance. Moreover, potential collisions are prevented by the addition of a close proximity object detection functionality. For this, a scaled prototype of the proposed system was developed by applying the “Vee Model” methodology where the requirements, architecture, solution design, implementation, and validation steps were followed. A successful proof-of-concept was accomplished after validating the capacity of the prototype to both identify and follow a person, while maintaining a safe distance, and to detect objects in the vehicle’s path. In addition, the documentation of the system’s design, development, and validation was achieved rendering the feature ready for full scale development. In conclusion, the “Trailer Reverse Assist - Optical Follow Me” system add-on can further assist in the process of backing-up a trailer safely in environments where the visibility is limited while also preventing collisions with nearby objects.ITESO, A. C.ContinentalConsejo Nacional de Ciencia y Tecnologí

Pembinaan modul soalan-soalan latihan berjawapan bagi mata pelajaran mekanik tanah

Modul Pembelajaran yang dibina adalah bertujuan untuk membantu pelajar dalam menguasai penyelesaian masalah proses pengiraan bagi mata pelajaran Mekanik Tanah. Mekanik Tanah adalah merupakan salah satu subjek yang memerlukan kemahiran di dalam teknik menjawab soalan-soalan latihan menyelesaikan masalah berdasarkan jalan kira yang lengkap. Kajian dijalankan ke atas penentuan tahap keperluan modul soalan-soalan latihan beijawapan bagi mata pelajaran Mekanik Tanah dari aspek kefahaman pelajar, gaya susunan proses pengiraan, kebolehlaksanaan dan sumber rujukan utama. Rekabentuk pembinaan modul adalah merujuk kepada model kerangka Biggs. Responden yang telah dipilih dalam menentukan tahap keperluan ke atas modul ini dari aspek-aspek di atas adalah terdiri daripada pelejar-pelajar Ijazah Saijana Muda Pendidikan Teknik dan Vokasional, KUiTTHO.Data yang diperolehi dianalisis menggunakan Statistical Packages for Social Science (SPSS) 11.0 for Windows. Data-data yang yang dikumpul dari soal selidik dianalisis menggunakan kaedah analisis statistik deskriptif. Tinjauan hasil dapatan ke atas keputusan analisis menunjukkan bahawa tahap keperluan ke atas keempat-empat aspek di atas adalah tinggi. Ini menunjukkan modul diperlukan. Kebanyakan responden bersetuju bahawa keperluan modul soalan-soalan latihan berjawapan ini adalah pada peratusan yang tinggi. Keputusan purata skor min menunjukkan setiap keperluan iaitu dari aspek kefahaman pelajar, gaya susunan proses pengiraan, kebolehlaksanaan dan sumber rujukan utama adalah pada tahap yang tinggi. Secara Keseluruhan hasil analisis bagi purata min skor menunjukkan (analisis spesifikasi 1 adalah 3.21, spesifikasi 2 ialah 3.32., spesifikasi 3 ialah 3.46 dan spesifikasi 4 ialah 3.48). Secara keseluruhan, pembinaan modul set jawapan ini berjaya memenuhi keperluan pelajar-pelajar Ijazah Sarjana Muda Pendidikan Teknik dan Vokasional yang mengambil mata pelajaran Mekanik Tana

Stormwater Intelligent Control System (2005)

Water restrictions, pollution control, volume balances, and the emergence of stormwater utilities have lead to the development of an automated intelligent system (“I-Water”) for water use and control. With the use of this system, water stored in stormwater ponds or in the surficial aquifer is not discharged to surface waters because it is used to meet water demands, such as, lawn irrigation, environmental protection, agriculture, drinking and industrial uses. The drop in groundwater levels and the increasing use of reclaimed water illustrates a need for alternative water supplies. Ground water depletion is occurring which is adding to the destruction of wetland areas and reduced spring flows. The supply of available reclaimed water continues to rise but so does the demand for irrigation water. The automation, water quality monitoring, and database that an Intelligent Water (“I-Water”) controller provides can make stormwater reuse systems more feasible thus helping to reduce stormwater pollutant loadings, maintain watershed volume balances, and provide an alternative irrigation water supply. Using advanced technology is an efficient and effective way to manage this valuable freshwater resource. Telecommunications has made it possible to monitor water flow, valves, collect data, read instrumentation such as water quality sensors and control things remotely and in \u27real time\u27. Presented in this report is an automated controller integrating multiple sensors, used to collect data that can be monitored daily (if desired) via home or office computers and that can remotely control the flow of water using home or office computers. The automated controller can be operated at the installation site or via telecommunications from a remote site. The “I-Water” will make stormwater volume control using reuse systems more feasible by decreasing O&M costs. Remote on-line monitoring to provide more reliable data at a greater frequency of collection is possible with the “I-Water” or similar systems. The I-Water” will provide access to pollutant monitoring to assure that the stormwater is safe to use for non-potable purposes. The “I-Water” is available for deployment