CSI sensing and control: Analytical and experimental results

Recent work on structural identification and large-angle maneuvers with vibration suppression was presented. The recent work has sought to balance structural and controls analysis activities by involving the analysts directly in the validation and experimental aspects of the research. Some new sensing, actuation, system identification, and control concepts were successfully implemented. An overview of these results is given

Technology requirements of exploration beyond Neptune by solar sail propulsion

This paper provides a set of requirements for the technology development of a solar sail propelled Interstellar Heliopause Probe mission. The mission is placed in the context of other outer solar systems missions, ranging from a Kuiper Belt mission through to an Oort cloud mission. Mission requirements are defined and a detailed parametric trajectory analysis and launch date scan performed. Through analysis of the complete mission trade space a set of critical technology development requirements are identified which include an advanced lightweight composite High-Gain Antenna, a high-efficiency Ka-band travelling-wave tube amplifier and a radioisotope thermoelectric generator with power density of approximately 12 W/kg. It is also shown that the Interstellar Heliopause Probe mission necessitates the use of a spinning sail, limiting the direct application of current hardware development activities. A Kuiper Belt mission is then considered as a pre-curser to the Interstellar Heliopause Probe, while it is also shown through study of an Oort cloud mission that the Interstellar Heliopause Probe mission is the likely end-goal of any future solar sail technology development program. As such, the technology requirements identified to enable the Interstellar Heliopause Probe must be enabled through all prior missions, with each mission acting as an enabling facilitator towards the next

Pioneer 11's encounter with Jupiter and mission to Saturn

Plans for Pioneer 11's approach to Saturn are described. A flyby somewhat parallel to the ring plane is being proposed as an interim target, with a future option held for a possible high risk (or suicide) plunge through the nearly transparent space between Saturn and its rings

Apollo Lightcraft Project

The ultimate goal for this NASA/USRA-sponsored Apollo Lightcraft Project is to develop a revolutionary manned launch vehicle technology which can potentially reduce payload transport costs by a factor of 1000 below the Space Shuttle Orbiter. The Rensselaer design team proposes to utilize advanced, highly energetic, beamed-energy sources (laser, microwave) and innovative combined-cycle (airbreathing/rocket) engines to accomplish this goal. The research effort focuses on the concept of a 100 MW-class, laser-boosted Lightcraft Technology Demonstrator (LTD) drone. The preliminary conceptual design of this 1.4 meter diameter microspacecraft involved an analytical performance analysis of the transatmospheric engine in its two modes of operation (including an assessment of propellant and tankage requirements), and a detailed design of internal structure and external aeroshell configuration. The central theme of this advanced propulsion research was to pick a known excellent working fluid (i.e., air or LN sub 2), and then to design a combined-cycle engine concept around it. Also, a structural vibration analysis was performed on the annular shroud pulsejet engine. Finally, the sensor satellite mission was examined to identify the requisite subsystem hardware: e.g., electrical power supply, optics and sensors, communications and attitude control systems

Development and testing of Parabolic Dish Concentrator No. 1

Parabolic Dish Concentrator No. 1 (PDC-1) is a 12-m-diameter prototype concentrator with low life-cycle costs for use with thermal-to-electric energy conversion devices. The concentrator assembly features panels made of a resin transfer molded balsa core/fiberglass sandwich with plastic reflective film as the reflective surface and a ribbed framework to hold the panels in place. The concentrator assembly tracks in azimuth and elevation on a base frame riding on a circular track. It is shown that the panels do not exhibit the proper parabolic contour. However, thermal gradients were discovered in the panels with daily temperature changes. The PDC-1 has sufficient optical quality to operate satisfactorily in a dish-electric system. The PDC-1 development provides the impetus for creating innovative optical testing methods and valuable information for use in designing and fabricating concentrators of future dish-electric systems

Violin Augmentation Techniques for Learning Assistance

PhDLearning violin is a challenging task requiring execution of pitch tasks with the left hand using a strong aural feedback loop for correctly adjusting pitch, concurrent with the right hand moving a bow precisely with correct pressure across strings. Real-time technological assistance can help a student gain feedback and understanding helpful for learning and maintaining motivation. This thesis presents real-time low-cost low-latency violin augmentations that can be used to assist learning the violin along with other real-time performance tasks. To capture bow performance, we demonstrate a new means of bow tracking by measuring bow hair de ection from the bow hair being pressed against the string. Using near- eld optical sensors placed along the bow we are able to estimate bow position and pressure through linear regression from training samples. For left hand pitch tracking, we introduce low cost means for tracking nger position and illustrate the combination of sensed results with audio processing to achieve high accuracy low-latency pitch tracking. We subsequently verify our new tracking methods' e ectiveness and usefulness demonstrating low-latency note onset detection and control of real-time performance visuals. To help tackle the challenge of intonation, we used our pitch estimation to develop low latency pitch correction. Using expert performers, we veri ed that fully correcting pitch is not only disconcerting but breaks a violinist's learned pitch feedback loop resulting in worse asplayed performance. However, partial pitch correction, though also linked to worse as-played performance, did not lead to a signi cantly negative experience con rming its potential for use to temporarily reduce barriers to success. Subsequently, in a study with beginners, we veri ed that when the pitch feedback loop is underdeveloped, automatic pitch correction did not signi cantly hinder performance, but o ered an enjoyable low-pitch error experience and that providing an automatic target guide pitch was helpful in correcting performed pitch error

Intelligent laser scanning for computer aided manufacture.

Reverse engineering requires the acquisition of large amounts of data describing the surface of an object, sufficient to replicate that object accurately using appropriate fabrication techniques. This is important within a wide range of commercial and scientific fields where CAD models may be unavailable for parts that must be duplicated or modified, or where a physical model is used as a prototype. The three-dimensional digitisation of objects is an essential first step in reverse engineering. Optical triangulation laser sensors are one of the most popular and common non-contact methods used in the data acquisition process today. They provide the means for high resolution scanning of complex objects. Multiple scans of the object are usually required to capture the full 3D profile of the object. A number of factors, including scan resolution, system optics and the precision of the mechanical parts comprising the system may affect the accuracy of the process. A single perspective optical triangulation sensor provides an inexpensive method for the acquisition of 3D range image data

APOLLO: the Apache Point Observatory Lunar Laser-ranging Operation: Instrument Description and First Detections

A next-generation lunar laser ranging apparatus using the 3.5 m telescope at the Apache Point Observatory in southern New Mexico has begun science operation. APOLLO (the Apache Point Observatory Lunar Laser-ranging Operation) has achieved one-millimeter range precision to the moon which should lead to approximately one-order-of-magnitude improvements in the precision of several tests of fundamental properties of gravity. We briefly motivate the scientific goals, and then give a detailed discussion of the APOLLO instrumentation.Comment: 37 pages; 10 figures; 1 table: accepted for publication in PAS

A Photogrammetric System for Model Attitude Measurement in Hypersonic Wind Tunnels

A series of wind tunnel tests have been conducted to evaluate a multi-camera videogrammetric system designed to measure model attitude in hypersonic facilities. The technique utilizes processed video data and photogrammetric principles for point tracking to compute model position including pitch, roll and yaw. A discussion of the constraints encountered during the design, and a review of the measurement results obtained from the NASA Langley Research Center (LaRC) 31-Inch Mach 10 tunnel are presented

Object Tracking Using Ambient Backscatter Technology

Ambient backscatter is a new technology that uses ambient signals to enable communication. The system utilizes existing ambient RF radiations as the source of power and also utilizes the same as wireless medium for communication between devices. It leverages the ambient RF signals that are already around us, it does not require a dedicated power infrastructure as in RFID. The basic thought here is that there is a ton of energy in our environment specifically in the form of high-amplitude RF waves from broadcasts, and we should be able to use that energy to do work. With the help of this ambient backscatter technology, we keep in track of the objects/things which we wish to safe guard by keeping them as a transmitter. There is exchange of pulses (RF signals) that takes place between the transmitter and the receiver. When the receiver to which the object is connected is taken away (to some particular distance), the backscattering stops and hence we may use the micro-controller to intimate the user with the help of a message using GSM and track the location of the object using GPRS