Real time pipelined system for forming the sum of products in the processing of video data

A 3-by-3 convolver utilizes 9 binary arithmetic units connected in cascade for multiplying 12-bit binary pixel values P sub i which are positive or two's complement binary numbers by 5-bit magnitide (plus sign) weights W sub i which may be positive or negative. The weights are stored in registers including the sign bits. For a negative weight, the one's complement of the pixel value to be multiplied is formed at each unit by a bank of 17 exclusive or gates G sub i under control of the sign of the corresponding weight W sub i, and a correction is made by adding the sum of the absolute values of all the negative weights for each 3-by-3 kernel. Since this correction value remains constant as long as the weights are constant, it can be precomputed and stored in a register as a value to be added to the product PW of the first arithmetic unit

Machine vision for space telerobotics and planetary rovers

Machine vision allows a non-contact means of determining the three-dimensional shape of objects in the environment, enabling the control of contact forces when manipulation by a telerobot or traversal by a vehicle is desired. Telerobotic manipulation in Earth orbit requires a system that can recognize known objects in spite of harsh lighting conditions and highly specular or absorptive surfaces. Planetary surface traversal requires a system that can recognize the surface shape and properties of an unknown and arbitrary terrain. Research on these two rather disparate types of vision systems is described

Time-delayed operation of a telerobot via geosynchronous relay

Operation of a telerobot is compromised if a time delay of more than a few hundred milliseconds exists between the operator and remote manipulator. However, the most economically attractive way to perform telerobotic functions such as assembly, maintenance, and repair in Earth orbit is via geosynchronous relay satellites to a ground-based operator. This induces loop delays from one-half to two seconds, depending on how many relays are involved. Such large delays makes direct master-slave, force-reflecting teleoperated systems infeasible. Research at JPL on a useful telerobot that operates with such time delays is described

Gas pipe explorer robot

A gas pipe explorer formed of a plurality of connecting elements, and an articulation element between the connected elements. The connected elements include drive capabilities, and the articulation element allows the connected elements to traverse gas pipes of arbitrary shapes and sizes. A sensor may sends the characteristics of the gas pipe, and the communication element may send back those sends characteristics. The communication can be wired, over a tether connecting the device to a remote end. Alternatively, the connection can be wireless, driven by either a generator or a battery

Method and apparatus for subsurface exploration

A subsurface explorer (SSX) for exploring beneath the terrestrial surface of planetary bodies such as the Earth, Mars, or comets. This exploration activity utilizes appropriate sensors and instrument to evaluate the composition, structure, mineralogy and possibly biology of the subsurface medium, as well as perhaps the ability to return samples of that medium back to the surface. The vehicle comprises an elongated skin or body having a front end and a rear end, with a nose piece at the front end for imparting force to composition material of the planetary body. Force is provided by a hammer mechanism to the back side of a nose piece from within the body of the vehicle. In the preferred embodiment, a motor spins an intermediate shaft having two non-uniform threads along with a hammer which engages these threads with two conical rollers. A brake assembly halts the rotation of the intermediate shaft, causing the conical roller to spin down the non-uniform thread to rapidly and efficiently convert the rotational kinetic energy of the hammer into translational energy

Small, Untethered, Mobile Robots for Inspecting Gas Pipes

Small, untethered mobile robots denoted gas-pipe explorers (GPEXs) have been proposed for inspecting the interiors of pipes used in the local distribution natural gas. The United States has network of gas-distribution pipes with a total length of approximately 109 m. These pipes are often made of iron and steel and some are more than 100 years old. As this network ages, there is a need to locate weaknesses that necessitate repair and/or preventive maintenance. The most common weaknesses are leaks and reductions in thickness, which are caused mostly by chemical reactions between the iron in the pipes and various substances in soil and groundwater. At present, mobile robots called pigs are used to inspect and clean the interiors of gas-transmission pipelines. Some carry magnetic-flux-leakage (MFL) sensors for measuring average wall thicknesses, some capture images, and some measure sizes and physical conditions. The operating ranges of pigs are limited to fairly straight sections of wide transmission- type (as distinguished from distribution- type) pipes: pigs are too large to negotiate such obstacles as bends with radii comparable to or smaller than pipe diameters, intrusions of other pipes at branch connections, and reductions in diameter at valves and meters. The GPEXs would be smaller and would be able to negotiate sharp bends and other obstacles that typically occur in gas-distribution pipes

Launching Payloads Into Orbit at Relatively Low Cost

A report proposes the development of a system for launching payloads into orbit at about one-fifth the cost per unit payload weight of current systems. The PILOT system was a solid-fuel, aerodynamically spun and spin-stabilized, five-stage rocket with onboard controls including little more than an optoelectronic horizon sensor and a timer for triggering the second and fifth stages, respectively. The proposal calls for four improvements over the PILOT system to enable control of orbital parameters: (1) the aerodynamic tipover of the rocket at the top of the atmosphere could be modeled as a nonuniform gyroscopic precession and could be controlled by selection of the initial rocket configuration and launch conditions; (2) the attitude of the rocket at the top of the first-stage trajectory could be measured by use of radar tracking or differential Global Positioning System receivers to determine when to trigger the second stage; (3) the final-stage engines could be configured around the payload to enhance spin stabilization during a half-orbit coast up to apoapsis where the final stage would be triggered; and (4) the final payload stage could be equipped with a "beltline" of small thrusters for correcting small errors in the trajectory as measured by an off-board tracking subsystem

Student Perceptions of Online Course Quality: A Comparison By Academic Discipline

The recent rapid proliferation of distance education necessitates the need for strong levels of academic accountability. An important factor found to influence and predict student success is students\u27 perceptions of their online courses. Understanding how learners perceive their online learning environment is paramount to effective course design and implementation. Therefore, the purpose of this study was to investigate community college students\u27 perceptions of online education. IHEP benchmarks for quality in distance education were used develop a web-based survey designed to measure if students\u27 perceptions of online course quality differed across academic disciplines, what factors impacted students\u27 perceptions of online course quality in regards to benchmarks for Teaching/Learning, Course Structure, and Student Support, and the level of impact of student demographics on perceptions of quality in online courses. No significant differences between groups were found to exist. Results showed that none of the factors investigated in this study, such as academic discipline, age, enrollment status, or previous exposure to college level online coursework, were found to have any effect on students\u27 perceptions of quality in online courses when compared between groups. These findings will provide valuable information to both online instructors and administrators in providing quality online education

Inflatable Hangar for Assembly of Large Structures in Space

The NASA Human Space Flight program is interested in projects where humans, beyond low-Earth orbit (LEO), can make an important and unique contribution that cannot be reasonably accomplished purely by robotic means, and is commensurate with the effort and cost associated with human spaceflight. Robotic space telescope missions have been conceived and launched as completed assemblies (e.g., Hubble) or as jack-in-the-box one-time deployments (e.g., James Webb). If it were possible to assemble components of a very large telescope from one or two launches into a telescope that was vastly greater in light-gathering power and resolution, that would constitute a breakthrough. Large telescopes on Earth, like all one-off precision assembly tasks, are done by humans. Humans in shirtsleeves (or cleanroom bunny suits) can perform tasks of remarkable dexterity and precision. Unfortunately, astronauts in pressure suits cannot perform such dexterous and precise tasks because of the limitations of the pressurized gloves. If a large, inflatable hangar were placed in high orbit, along with all the components needed for a large assembly such as a large telescope, then humans in bunny suits could perform the same sorts of extremely precise and dexterous assembly that they could be expected to perform on Earth. Calculations show that such an inflatable hangar, and the necessary gas to make it safe to occupy by shirtsleeves humans wearing oxygen masks, fits within the mass and volume limitations of the proposed "Space Launch System" heavy-lift rocket. A second launch could bring up all the components of an approximately 100-meter-diameter or larger telescope. A large [200 ft (approximately 61 m) in diameter] inflated fabric sphere (or hangar) would contain four humans in bunny suits. The sphere would contain sufficient atmospheric pressure so that spacesuits would not be necessary [about 3.2 psi (approximately 22 kPa)]. The humans would require only oxygen masks and small backpacks similar to SCUBA tanks. The oxygen content of the gas would be about 35%, low enough to reduce fire risk but high enough to sustain life in the event of a failure of an oxygen mask. The bunnysuited astronauts could ride on long "cherry-picker" robots with foot restraints somewhat similar to the arm on the International Space Station. Other astronauts would maneuver freely with small propeller fans on their backpacks to provide thrust in the zero-g environment