Photovoltaic stand-alone modular systems, phase 2

The final hardware and system qualification phase of a two part stand-alone photovoltaic (PV) system development is covered. The final design incorporated modular, power blocks capable of expanding incrementally from 320 watts to twenty kilowatts (PK). The basic power unit (PU) was nominally rated 1.28 kWp. The controls units, power collection buses and main lugs, electrical protection subsystems, power switching, and load management circuits are housed in a common control enclosure. Photo-voltaic modules are electrically connected in a horizontal daisy-chain method via Amp Solarlok plugs mating with compatible connectors installed on the back side of each photovoltaic module. A pair of channel rails accommodate the mounting of the modules into a frameless panel support structure. Foundations are of a unique planter (tub-like) configuration to allow for world-wide deployment without restriction as to types of soil. One battery string capable of supplying approximately 240 ampere hours nominal of carryover power is specified for each basic power unit. Load prioritization and shedding circuits are included to protect critical loads and selectively shed and defer lower priority or noncritical power demands. The baseline system, operating at approximately 2 1/2 PUs (3.2 kW pk.) was installed and deployed. Qualification was successfully complete in March 1983; since that time, the demonstration system has logged approximately 3000 hours of continuous operation under load without major incident

Feasibility study of the Boeing Small Research Module (BSRM) concept

The design, capabilities, and subsystem options for the Boeing Small Research Module (BSRM) are described. Specific scientific missions are defined based on NASA-Ames Research Center requirements and the BSRM capability to support these missions is discussed. Launch vehicle integration requirements and spacecraft operational features are also presented

Design and Development of a Low-Cost Multi-Channel Re-Programmable Electro-Pneumatic Actuator Kit

The objective of the research was to develop a low-cost, multi-channel electro-pneumatic actuator kit that would be conveniently accessible for students' learning experiences, trainings, and research at the individual and academic level. The essential feature of this kit was the inclusion of multi-channel outputs, which implies that the student may not only examine the behavior of basic pneumatic actuators but also train their minds to operate complicated actuation systems. With this electro-pneumatic actuation kit, a student can build and utilize it in a variety of research areas, as well as regulate a system synchronously or asynchronously with greater efficiency. The device is portable, inexpensive, and simple to use. It has a power source of 12 VDC for the electrical circuit and can provide a maximum pressure of 90 kPa as well as vacuum of -40 kPa. Relays were being integrated to satisfy the smooth automation of the kit. It features the MPX700 differential pressure sensor, which allows the user to measure and manage the needed pressure. All of the components were controlled by the Arduino Board, which is affordable and can be programmed to do the required function. With this research, academic institutions will be able to create their own kits for their students, allowing them to discover numerous new inventive concepts

Design and Development of a Low-Cost Multi-Channel Re-Programmable Electro-Pneumatic Actuator Kit

The objective of the research was to develop a low-cost, multi-channel electro-pneumatic actuator kit that would be conveniently accessible for students' learning experiences, trainings, and research at the individual and academic level. The essential feature of this kit was the inclusion of multi-channel outputs, which implies that the student may not only examine the behavior of basic pneumatic actuators but also train their minds to operate complicated actuation systems. With this electro-pneumatic actuation kit, a student can build and utilize it in a variety of research areas, as well as regulate a system synchronously or asynchronously with greater efficiency. The device is portable, inexpensive, and simple to use. It has a power source of 12 VDC for the electrical circuit and can provide a maximum pressure of 90 kPa as well as vacuum of -40 kPa. Relays were being integrated to satisfy the smooth automation of the kit. It features the MPX700 differential pressure sensor, which allows the user to measure and manage the needed pressure. All of the components were controlled by the Arduino Board, which is affordable and can be programmed to do the required function. With this research, academic institutions will be able to create their own kits for their students, allowing them to discover numerous new inventive concepts

System Guidelines for EMC Safety-Critical Circuits: Design, Selection, and Margin Demonstration

Demonstration of required safety margins on critical electrical/electronic circuits in large complex systems has become an implementation and cost problem. These margins are the difference between the activation level of the circuit and the electrical noise on the circuit in the actual operating environment. This document discusses the origin of the requirement and gives a detailed process flow for the identification of the system electromagnetic compatibility (EMC) critical circuit list. The process flow discusses the roles of engineering disciplines such as systems engineering, safety, and EMC. Design and analysis guidelines are provided to assist the designer in assuring the system design has a high probability of meeting the margin requirements. Examples of approaches used on actual programs (Skylab and Space Shuttle Solid Rocket Booster) are provided to show how variations of the approach can be used successfully

Analysis of safety critical plc code against IEC 1508 development techniques

The aim of this thesis is to assess the applicability of recommended software development techniques defined in IEC 1508 [8] to PLC (Programmable Logic Controller) code developed for offshore oil platforms. The draft standard TEC 1508 contains specific recommendations which have the objective of improving the safety characteristics of safety critical code The recommended techniques could have one of the following characteristics with regard to offshore PLC code: • They are already used in the development of code. • They could be used in the development of the code. • They could not be used due to the application domain. • They could not be used due to the specific programming environment analysed. It was the aim of the thesis to characterise a subset of the IEC 1508 techniques into the above categories. The analysis was requested by the Health and Safety Executive (HSE) Offshore Division. The analysis has been performed using two major case studies, taken from live industrial safety-critical systems operating on a North Sea Oil Platform; they both comprise 300K lines of code in total. Both systems were written in three high level PLC languages. It was decided to translate the code into one language, so the analysis was undertaken in terms of a single language. A translator has been written, and a number of static analysis tools, therefore allowing all the code to be analysed. The key twenty two recommendations from IEC 1508 have been selected, and the case study systems correspondingly analysed, using a modified Goal Question Metric (GQM) approach as a unified framework. The overall analysis method has been found to be successful in supporting the detailed analysis of IEC 1508 recommendations. The thesis presents detailed conclusions on each analysed technique, as well as more general observations on the PLC code

The programmable logic controller : its prehistory, emergence and application

Programmable Logic Controllers (PLCs) are widely used devices controlling industrial machines and processes and many other diverse applications, requiring primarily, combinatorial logic and sequential control. The PLC is a hidden technology, little known by the general public and overlooked in academic historical studies of technology. The research reported in this thesis aims to address this lack of awareness. The thesis explores the development of sequential and combinatorial logic control technologies, the emergence of the PLC, its subsequent development and its industrial applications. Patents and first- hand accounts and experiences from senior industrial engineers in a number of diverse manufacturing industries have been used as the primary research sources since, as a hidden technology, academic historical accounts are sparse. This approach illustrates, through using the PLC as an example, a potential method of studying other, unrelated hidden technologies. The research has revealed the influence of geography, industrial settings and earlier engineering practices on the design, selection and application of PLC control technologies, and comments on the how these influences define specific communities of practice

The Mercury-Redstone project

Mercury-Redstone project development history, and contributions to future manned spacecraft design and operatio

OPERATION AND PROCESS CONTROL DEVELOPMENT FOR A PILOT-SCALE LEACHING AND SOLVENT EXTRACTION CIRCUIT RECOVERING RARE EARTH ELEMENTS FROM COAL-BASED SOURCES

The US Department of Energy in 2010 has identified several rare earth elements as critical materials to enable clean technologies. As part of ongoing research in REEs (rare earth elements) recovery from coal sources, the University of Kentucky has designed, developed and is demonstrating a ¼ ton/hour pilot-scale processing plant to produce high-grade REEs from coal sources. Due to the need to control critical variables (e.g. pH, tank level, etc.), process control is required. To ensure adequate process control, a study was conducted on leaching and solvent extraction control to evaluate the potential of achieving low-cost REE recovery in addition to developing a process control PLC system. The overall operational design and utilization of Six Sigma methodologies is discussed. Further, the application of the controls design, both procedural and electronic for the control of process variables such as pH is discussed. Variations in output parameters were quantified as a function of time. Data trends show that the mean process variable was maintained within prescribed limits. Future work for the utilization of data analysis and integration for data-based decision-making will be discussed

Advanced flight control system study

A fly by wire flight control system architecture designed for high reliability includes spare sensor and computer elements to permit safe dispatch with failed elements, thereby reducing unscheduled maintenance. A methodology capable of demonstrating that the architecture does achieve the predicted performance characteristics consists of a hierarchy of activities ranging from analytical calculations of system reliability and formal methods of software verification to iron bird testing followed by flight evaluation. Interfacing this architecture to the Lockheed S-3A aircraft for flight test is discussed. This testbed vehicle can be expanded to support flight experiments in advanced aerodynamics, electromechanical actuators, secondary power systems, flight management, new displays, and air traffic control concepts