Engine Data Interpretation System (EDIS), phase 2

A prototype of an expert system was developed which applies qualitative constraint-based reasoning to the task of post-test analysis of data resulting from a rocket engine firing. Data anomalies are detected and corresponding faults are diagnosed. Engine behavior is reconstructed using measured data and knowledge about engine behavior. Knowledge about common faults guides but does not restrict the search for the best explanation in terms of hypothesized faults. The system contains domain knowledge about the behavior of common rocket engine components and was configured for use with the Space Shuttle Main Engine (SSME). A graphical user interface allows an expert user to intimately interact with the system during diagnosis. The system was applied to data taken during actual SSME tests where data anomalies were observed

Framework for a space shuttle main engine health monitoring system

A framework developed for a health management system (HMS) which is directed at improving the safety of operation of the Space Shuttle Main Engine (SSME) is summarized. An emphasis was placed on near term technology through requirements to use existing SSME instrumentation and to demonstrate the HMS during SSME ground tests within five years. The HMS framework was developed through an analysis of SSME failure modes, fault detection algorithms, sensor technologies, and hardware architectures. A key feature of the HMS framework design is that a clear path from the ground test system to a flight HMS was maintained. Fault detection techniques based on time series, nonlinear regression, and clustering algorithms were developed and demonstrated on data from SSME ground test failures. The fault detection algorithms exhibited 100 percent detection of faults, had an extremely low false alarm rate, and were robust to sensor loss. These algorithms were incorporated into a hierarchical decision making strategy for overall assessment of SSME health. A preliminary design for a hardware architecture capable of supporting real time operation of the HMS functions was developed. Utilizing modular, commercial off-the-shelf components produced a reliable low cost design with the flexibility to incorporate advances in algorithm and sensor technology as they become available

Determination of Uncertainties for the New SSME Model

This report discusses the uncertainty analysis performed in support of a new test analysis and performance prediction model for the Space Shuttle Main Engine. The new model utilizes uncertainty estimates for experimental data and for the analytical model to obtain the most plausible operating condition for the engine system. This report discusses the development of the data sets and uncertainty estimates to be used in the development of the new model. It also presents the application of uncertainty analysis to analytical models and the uncertainty analysis for the conservation of mass and energy balance relations is presented. A new methodology for the assessment of the uncertainty associated with linear regressions is presented

Autonomous Sensor Signal Acquisition System

Tato práce se zabývá návrhem a realizací autonomního systému pro záznam signálů ze senzorů pro měření na malých a těžce přístupných místech. Zařízení podporuje připojení osmi analogových vstupů, tří digitálních I2C vstupů, čtyř univerzálních binárních vstupů a obsahuje vestavěný digitální akcelerometr. Zařízení dále poskytuje programovatelné proudové zdroje pro napájení analogových senzorů a obvody pro zesílení signálů z analogových vstupů. Zařízení podporuje dva módy. V režimu autonomního měření jsou po uživatelem nastavený čas zaznamenávána data z jednotlivých senzorů. Naměřená data jsou ukládána na interní microSD kartu. V režimu přenosu mohou být skrze webovou stránku konfigurovány parametry měření a stahovány soubory s naměřenými daty. Možnost připojení indukční nabíječky zajišťuje kompletní bezdrátovost celého zařízení. Práce se zabývá hardwarovým řešením a návrhem firmwaru do mikrokontroléru STM32F411VE sloužícímu k ovládání celého zařízení a do mikrokontroléru ESP8266 obsaženém uvnitř Wi-Fi modulu.This thesis discusses the concept and the realisation of the autonomous sensor signal acquisition system for measurement in small and hardly accessible places. The device supports eight analog inputs, onboard digital accelerometer, three I2C digital inputs and four universal binary inputs. The device also provides programmable power sources for analog sensors and signal conditioners for amplification of the measured analog signal. The device provides two modes. In the stand-alone mode, the system with specified settings records data for given time. The measured data are stored to the microSD card. In transfer mode, the system can be configured through the web page, and the files with measured data can be downloaded. The possibility of using inductive charging ensures the complete wireless device operation. This text considers the hardware solutions and the firmware design for the STM32F411VE microcontroller used to control the device and for the ESP8266 microcontroller included in the Wi-Fi module

Stochastic Verification Theorem for Infinite Dimensional Stochastic Control Systems

The verification theorem serving as an optimality condition for the optimal control problem, has been expected and studied for a long time. The purpose of this paper is to establish this theorem for control systems governed by stochastic evolution equations in infinite dimensions, in which both the drift and the diffusion terms depend on the controls

Failure Control Techniques for the SSME

Since ground testing of the Space Shuttle Main Engine (SSME) began in 1975, the detection of engine anomalies and the prevention of major damage have been achieved by a multi-faceted detection/shutdown system. The system continues the monitoring task today and consists of the following: sensors, automatic redline and other limit logic, redundant sensors and controller voting logic, conditional decision logic, and human monitoring. Typically, on the order of 300 to 500 measurements are sensed and recorded for each test, while on the order of 100 are used for control and monitoring. Despite extensive monitoring by the current detection system, twenty-seven (27) major incidents have occurred. This number would appear insignificant compared with over 1200 hot-fire tests which have taken place since 1976. However, the number suggests the requirement for and future benefits of a more advanced failure detection system

Optimal Consumption--Investment Problems under Time-Varying Incomplete Preferences

The main objective of this paper is to develop a martingale-type solution to optimal consumption--investment choice problems ([Merton, 1969] and [Merton, 1971]) under time-varying incomplete preferences driven by externalities such as patience, socialization effects, and market volatility. The market is composed of multiple risky assets and multiple consumption goods, while in addition there are multiple fluctuating preference parameters with inexact values connected to imprecise tastes. Utility maximization is a multi-criteria problem with possibly function-valued criteria. To come up with a complete characterization of the solutions, first we motivate and introduce a set-valued stochastic process for the dynamics of multi-utility indices and formulate the optimization problem in a topological vector space. Then, we modify a classical scalarization method allowing for infiniteness and randomness in dimensions and prove results of equivalence to the original problem. Illustrative examples are given to demonstrate practical interests and method applicability progressively. The link between the original problem and a dual problem is also discussed, relatively briefly. Finally, using Malliavin calculus with stochastic geometry, we find optimal investment policies to be generally set-valued, each of whose selectors admits a four-way decomposition involving an additional indecisiveness risk-hedging portfolio. Our results touch on new directions for optimal consumption--investment choices in the presence of incomparability and time inconsistency, also signaling potentially testable assumptions on the variability of asset prices. Simulation techniques for set-valued processes are studied for how solved optimal policies can be computed in practice.Comment: 72 pages, 1 table, 13 figure

Leone M. Evans, Ralph Evans, Bernice Evans Stuart, and Beth Evans Johnson v. Glen S. Stuart : Respondent\u27s Brief

Appeal from the Judgment and Order of the Second Judicial District Court for Davis County Honorable Charles G. Cowley, District Judg

Robust Time-inconsistent Linear-Quadratic Stochastic Controls: A Stochastic Differential Game Approach

This paper studies robust time-inconsistent (TIC) linear-quadratic stochastic control problems, formulated by stochastic differential games. By a spike variation approach, we derive sufficient conditions for achieving the Nash equilibrium, which corresponds to a time-consistent (TC) robust policy, under mild technical assumptions. To illustrate our framework, we consider two scenarios of robust mean-variance analysis, namely with state- and control-dependent ambiguity aversion. We find numerically that with time inconsistency haunting the dynamic optimal controls, the ambiguity aversion enhances the effective risk aversion faster than the linear, implying that the ambiguity in the TIC cases is more impactful than that under the TC counterparts, e.g., expected utility maximization problems

Anomaly

ANOMALY is a dramatic dance. It is concerned with fear of new ideas and with violence and intolerance that are often a result of this fear. Because of the dramatic and emotional content of the piece the choreographer chose to make this statement of fear of new ideas by illustrating it through a specific event. The dance has a plot that has to be carefully revealed so that an audience could follow it. The choreographer used the flash back technique. It became important to the choreographer to know how the audience perceives in order to know what images to present. It then became necessary to investigate theories of perception. Rudolf Arnheim was found to have several publications that were applicable. The music used was Claude Debussy's Le Martyre de St. Sebastian. The dance has six people, a soloist who represents the Anomaly, and two groups of two and three who represent people who cannot tolerate new ideas. The soloist and the two groups are seen all together as the lights come up. The set suggests a barren, formidable place full of rocks and crags. The costumes they wear suggest Medieval skirts but are intended to be symbolic rather than authentic in representation. We get the impression that something horrible has happened when the groups rush frantically to center stage. Their agitated movements subside as they seem to calm themselves and they turn, each in a different direction, and move off stage all doing the same movement pattern. All this is done to silence