International Telemetering Conference Proceedings / October 29-November 02, 1990 / Riviera Hotel and Convention Center, Las Vegas, Nevada / TIW Systems has developed a modern, compact, modular, antenna controller (ACU) for telemetry, tracking, and communications antennas. The controller combines the functions of an antenna control unit, a position conversion/display chassis, and a polarization control unit. By using plug-in cards, a tracking receiver, autophasing control unit, tracking synthesizer, and other functions can be added. Depending on the requirements, the tracking receiver can be a simple wide-band steptrack receiver, or can be a full function phase-locked-loop (PLL) autotrack receiver. In the past, all this capability would have taken a large portion of an entire equipment rack. The unit uses modern microprocessor technology for digitally controlling the position and rate of the antenna. Advanced tracking modes and remote control can be added by connecting an external computer (PTIC) to one of the ACU’s serial ports. The PTIC also provides a user friendly operator interface through the use of high resolution color graphics and easy to understand menus.

This study presents methods for understanding, modeling and control of tele-operated pneumatic actuators for rehabilitation in Magnetic Resonance Imaging (MRI). Pneumatic actuators have excellent MRI-compatibility as opposed to conventional electro-mechanical systems; however, the actuator and the system drivers cannot be co-located due to the MRI-compatibility requirements. The actuators are driven via long transmission lines, which affect the system dynamics significantly. Methods provided in this work produced accurate pressure estimation and control by accounting for the pressure dynamics in the lines, which has been neglected by previous work in this area. The effectiveness of the presented modeling and control methods were demonstrated on tele-operation test setups. This research also includes the design of necessary system components for the developed algorithms. An MRI-compatible optical sensor was developed for force feedback and its design was analyzed for high precision. Directions and opportunities for future research are discussed.

Vibration in internal turning is a problem in the manufacturing industry. Vibrations appear under the excitation applied by the material deformation process during the machining of a workpiece. In order for a lathe to perform an internal turning or boring operation, for example, in a pre-drilled hole in a workpiece, it is generally required that the boring bar should be long and slender; therefore extra sensitive to vibrations. These vibrations will affect the result of machining, in particular the surface finish, also the tool life may be reduced. As a result of tool vibration, severe acoustic noise frequently occurs in the working environment. This thesis comprises three parts and the first part presents a method for active control of boring bar vibration. This method consists of an active boring bar controlled by, for example, an analog controller. The focus lies on the analog controller and the advantages that may be obtained from working in the analog domain. The controller is a lead-lag compensator with digitally controlled parameters, such as gain and phase. However, signals remain in the analog domain. In addition, the analog controller is compared with a digital adaptive controller and it is found that both controllers yield an attenuation of the vibration by up to 50 dB. The second part of this thesis concerns the dynamic properties of a clamped boring bar used by the industry. In order to design a robust controller for a certain system, knowledge about the system's dynamic properties is required. On the workshop floor, a boring bar is dismounted and remounted, and reconfiguration of boring bars will alter the dynamic properties of the clamped boring bar. The dynamic properties of a standard boring bar and an active boring bar for a number of possible clamping conditions, as well as for a linearized clamping have been investigated based on an experimental approach. Also simple Euler-Bernoulli modeling of clamped boring bars incorporating simple non-rigid models of the boring bar clamping are investigated. Initial simulations of nonlinear SDOF systems have been carried out: one with a signed squared stiffness and one with a cubic stiffness. The purpose of these simulations was to identify a nonlinearity that introduces a similar behavior in the SDOF system dynamics as the nonlinear behavior observed in the dynamic properties of a clamped boring bar. The third and final part of this thesis focuses on vibration analysis methods in engineering education. A signal analyzer (which is a commonly used instrument in signal processing and vibration analysis) was made accessible via the Internet. Assignments were developed for students to learn and practice vibration analysis on real signals from a real setup of a relevant structure; a clamped boring bar. Whilst the experimental setup was fixed, the instrument and sensor configuration nonetheless enable a variety of experiment, for example: excitation signal analysis, spectrum analysis and experimental modal analysis.

<p>The Lunar Rover (Roony) is a robotic project group at Mälardalens University composed by students. The objective of this group is to design and build an autonomous robot that has to be able to move by itself through the moon terrain.</p><p>The Lunar Rover is divided in several sub-projects from different knowledge areas; the objective of this electronic thesis is to design a controller board.</p><p> </p><p>The designed board will be able to connect the robot to an external dispositive (via JTAG, or WIFI), and also it will control and connect the different robot’s peripherals.</p><p>The main component of the controller board is the microcontroller AT90CAN128.</p><p>The peripherals are a steeper motor, a LIDAR system (Light Detection And Ranging), a WIFI chip(WIPORT™), a bus can driver, an accelerometer, a LIPO( Lithium-Ion Polymer) battery charger, a Solar photovoltaic cell handler, and sixteen DC motors(four in each leg of the robot).</p><p>Once the logic design has finished, the PCB design is done attending the size limitations of the robot. Once the design has finished, a prototype has been built and tested using ATMEL software.</p>

No description available.

Certain single input, linearised extremum controllers of the empirical type described in the literature have been designed and their performances have been compared to that of an approximately optimal controller. The plant is subject to disturbances, lags and measurement noise. A dimensionless performance criterion and description of the plant have been used to present the results. A design procedure for a sinusoidal perturbation controller in connection with the above plant has been obtained, using a linear equivalent circuit for the system together with an experimentally obtained estimate of the equivalent circuit validity. Experimental results have shown that the resulting design is the best, and that the system is likely to remain stable, when the performance of the system is limited mainly by the measurement noise. This empirical controller has been compared with Roberts approximately optimal controller and has been shown to perform equally well if the effect of the lag is small. The performances of three different types of extremum controller have been compared when the plant lags can be neglected. The three controllers use sine wave perturbation, square wave perturbation, and square wave perturbation with a sample and hold unit in the controller. It has been shown that all three the perturbation frequency is infinite. When the perturbation frequency is limited, as in a practical system, the controllers without the sample and hold unit give better performance, at the expense of requiring the adjustment of an additional controller parameter.

No description available.

No description available.

Varje företag har sitt eget sätt att ta fram sin budget. Controllern har ofta en central roll vid budgetarbetet och ser till att budgeten sammanfaller efter de mål som företaget satt upp. Företag använder sig av olika IT-system i sina verksamheter och dessa kan vara till hjälp vid framtagningen av budgeten. Syftet med denna studie är att studera hur företag framställer sin budget ur controllerns synvinkel. Vi kommer även att se hur IT-system kan stödja controllern och medarbetarnas verksamhet. För att få en djupare förståelse av ämnet har vi valt att genomföra en kvalitativ studie med en abduktiv ansats. I vår teoretiska referensram sker en genomgång av studiens centrala begrepp, controllern, budgeten, informationssystemet samt ERP-systemet. Vi har genomfört tre besöksintervjuer för att studera hur dessa genomför sin budgetprocess och hur IT-systemen kan vara till stöd. Varje intervju spelades in och gjordes på respondentens arbetsplats. Resultatet av denna studie visar att företag arbetar på likartade sätt i budgetprocessen genom en iterativmetod. Företag använder IT-systemen för att finna historiken från tidigare år samt för att skapa budgeten. De tar hjälp från analysverktyg som Excel och skapar revideringar av budgeten genom prognoser.

Bakgrund: En åtgärd för att effektivisera stödfunktioner i organisationer är att etablera och använda sig av så kallade SSC. Det innebär att spridda stödfunktionerna flyttas till ett separat och ansvarigt bolag inom koncernen. Där redovisarna arbetar på SSC medan controllers arbetar ute i organisationen. Det är vanligt förekommande att arbetsfördelningen aldrig når fullt ut mellan redovisarna och controllers, vilket har påvisats på det studerade företaget. Syfte: Det övergripande syftet för studien är att öka kunskapen om hur arbetsförhållandet kan organiseras mellan redovisare och controllers när yrkesrollerna utvecklas och förändras i en global organisation. Metod: Studien innefattar en fallstudie av en globalorganisation inom detaljhandel. Datainsamling för studien har skett genom semi-strukturerade intervjuer och företagsdokumentation. Slutsatser: I studien har det påvisats att bolagsansvarig (redovisaren) har en specialistoch konsulteranderoll, som hanterar redovisning och utför viss transaktionshantering. Business navigators (controllers) har en affärsparterroll och ”navigerar” verksamheter. En rad problemområden samt åtgärder för arbetsfördelningen har identifierats och är presenterade i tabell 14. En ny konceptuell modell, figur 12 presenteras i slutsatsen.