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Quality improvement has been an objective of many manufacturing operations. As the quality improvement thrust has made its way across America plants have attempted to improve quality through the use of SPC. While numerous operations believed that this was “the solution” to cure manufacturing problems, experience has shown that it is just a tool. Honest attempts to make SPC a success have forced a revaluation of the tool in light of management philosophy and worker involvement. The Process Control System (PCS) is a series of steps that has been learned in the school of hard knocks. It is considered to be the most efficient method of implementing true process control. The process goes far beyond the typical SPC training to Include setting the stage for the training, as well as a technical analysis of the factors and management culture that effect long term implementation.

The use of an on-board microprocessor to acquire data on truck and bus performance during in-service operation enables the information transmitted by measurement sensors to be examined, processed, compacted or aggregated, and stored in memory by the on-board computer software. The system development requires a careful balance of the tradeoffs between hardware and software concepts which is quite different from considerations applied with normal “laboratory” type data acquisition systems.

Operating procedures for keyboard data entry in avionics are analyzed. The type of information being entered may be identified either before or after entry of the alphanumeric characters. The keys which are used to identify the type of data may be collected in a centralized control unit or distributed throughout the cockpit adjacent to the associated displays. The Collins NCS-31 and the King KCU 565 navigation and control systems are discussed as illustrations of two sets of choices for operating procedures. Emphasis is placed upon correspondence between the thought processes associated with data entry and the pilot's actions in entering data.

The Space Shuttle Orbiter Atmospheric Revitalization Pressure Control System (ARPCS) and the Fuel Cell System (FCS) use a hot wire anemometer type of gas mass flow sensor for flow measurement. In the ARPCS oxygen and nitrogen mass flows are measured and in the FCS oxygen and hydrogen mass flows are measured. The existing flow sensors suffer from certain accuracy limitations and potential failure modes. A new type of commercially developed solid state micro-machined silicon gas mass flow sensor developed by Honeywell was adapted to allow the technology to be assessed for the application. A demonstration test program has been conducted to evaluate the performance characteristics of the new sensor for space system applications and environments. The testing was sponsored by the National Aeronautics and Space Administration (NASA) at the Johnson Space Center (JSC).

The early external active thermal control system (EEATCS) is designed to cool the U.S. Laboratory (USL), during early assembly stages of the International Space Station (ISS), to support assured early research (AER). The ISS is assembled on orbit over a period of about 5 years and over 40 stages. During later stages, about half way through the assembly, the USL is cooled by the external active thermal control system (EATCS), but that system is not available during early stages. To assure research, during early stages, the USL is cooled by the EEATCS; at a later stage, the USL cooling is switched to EATCS. During early stages, electric power is provided by the integrated truss segment (ITS) P6, which consists of photovoltaic (PV) arrays to convert sunlight into direct current power, an integrated equipment assembly (IEA) to support hardware required to store and condition electric power, and a long spacer to provide spacing between outboard power modules.

This paper presents classical control algorithms design for the solar array pointing system of the Space Station Freedom (SSF). This development is based on continuous, rigid body model of the solar array beta gimbal assembly (BGA) containing both linear and nonlinear dynamics due to various friction components. Optimum sets of controller parameters were obtained based on integral performance criteria through EASY5 simulations in the time domain. Classical sensitivity studies conducted in EASY5 indicated that the worst potential problem (possible system instability) is due to the variations in the electric motor dead-zone characteristics. After incorporation of an alternate static friction model, a Taguchi based tolerance design sensitivity study was conducted. Results indicated that the voltage variance, torque sensitivity constant and the motor resistance are the most important tolerances investigated with respect to integral square error (ISE).

The need for evaluating and optimizing airframes of advanced aircraft configurations with exceptional speed and accuracy has resulted in the development of highly sophisticated computerized techniques. Sensitivity of these programs to advanced materials, construction types, aeroelasticity, structural dynamics, configuration geometry, airloads, missions, and performance has all but obsoleted the statistical approach to the problem solution. The competitive nature of the field has also placed unusually severe demands on calendar time available for such evaluations. This has resulted in the development of integrated analytical computer programs that have the required sensitivity and rapid turnaround time to face the competitive nature of today's environment.

An integral space power concept provides both the electrical power and propulsion from a common heat source and offers superior performance capabilities over conventional orbital insertion using chemical propulsion systems. This paper describes a hybrid (bimodal) system concept based on a proven, inherently safe solid fuel form for the high temperature reactor core operation and rugged planar thermionic energy converter for long-life steady state electric power production combined with NERVA-based rocket technology for propulsion. The integral system is capable of long-life power operation and multiple propulsion operations. At an optimal thrust level, the integral system can maintain the minimal delta-V requirement while minimizing the orbital transfer time. A trade study comparing the overall benefits in placing large payloads to GEO with the nuclear electric propulsion option shows superiority of nuclear thermal propulsion.

The Rocketdyne Division of Rockwell International Corporation is currently researching and evaluating the use of Artificial Intelligence and in particular Expert System technologies for the monitoring of large space-based electric power systems such as NASA's Space Station Freedom (SSF). Power System Security of space borne and lunar based electrical power systems provide unique challenges to power system software design engineers. The major responsibility of Power System Security is the monitoring of the state of health of the Power Distribution System. The role of system security is to ensure that uninterrupted electrical power of high quality is distributed to all the load centers [1]. Voltage, current, power source reliability, and power quality are main components that describe the integrity of an electrical power system and fall into the area of security control.

Mathematical modeling of the Ni-H2 cell based on the fundamental electrochemical processes is necessary for accurately simulating the battery behavior on Space Station Freedom. Accurate predictions are incorporated as part of the development of the Space Station Electric Power System simulation. This simulation will be used to develop and test control algorithms which will maximize the available power in the most efficient way. This is a deviation from the approach used on smaller satellite power systems which are designed with substantial margin. Hence, the use of an empirical battery model is not feasible due to its low fidelity. This paper covers the electrochemical theory related to the Ni-H2 cells, and the analysis of experimental data used to develop relations between the cell state of charge and certain cell properties. Theoretical results are compared against well-documented experimental data.