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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Development of a Control Systems Platform for an Autonomous Soft-Car

Ray, Pratish January 2015 (has links)
Balloon Cars (Soft Cars) used for active-system testing are presently statically following one specific path. Autonomous GPS driven balloon cars can be extremely useful if made to be accurate.Volvo group’s long term plan involves usage of such cars to improve active-safety systems. Thisreport presents comprehensive details about the development of the control system of the soft-car.Software development was preceded by purchase of parts. Detailed descriptions of the ballooncar hardware components are presented. Various hardware components were interconnected toform a CAN Bus network. This thesis work describes CAN networks in general and with referenceto the developed Linux based software system.The navigation system is presented in the thesis report using a ‘bottom up’ approach. First theLow-level functions and variables are described that directly control the hardware component.They are called by high level functions that are subsequently explained. The high level functionsinclude accurate turning and an automated lane change process.The high level functions may be sequentially called and to accurately follow a specific path. Various lines and points may be used in a user defined Cartesian coordinate system. Details about theperformance of various high level functions as well as of a demonstration of a pattern are presented along with the limitations of the overall system.
112

Distributed real-time control via the internet

Srivastava, Abhinav 30 September 2004 (has links)
The objective of this research is to demonstrate experimentally the feasibility of using the Internet for a Distributed Control System (DCS). An algorithm has been designed and implemented to ensure stability of the system in the presence of upper bounded time-varying delays. A single actuator magnetic ball levitation system has been used as a test bed to validate the proposed algorithm. Experiments were performed to obtain the round-trip time delay between the host PC and the client PC under varying network loads and at different times. A digital real-time lead-lag controller was implemented for the magnetic levitation system. Upper bounds for the artificial and experimental round-trip time delay that can be accommodated in the control loop for the maglev system were estimated. The artificial time delay was based on various probabilistic distributions and was generated through MATLAB. To accommodate sporadic surges in time delays that are more than these upper bounds, a timeout algorithm with sensor data prediction was developed. Experiments were performed to validate the satisfactory performance of this algorithm in the presence of the bonded sporadic excessive time delays.
113

Architecture for Diagnostic Platform

Hedfors, Sara January 2010 (has links)
In order to maximize operating time of an industrial machine and minimize stand-by time, service time and operating costs, a diagnostic system can be a useful tool. Diagnostic systems employ information already available in a machine’s control system (such as control signals, system state, sensor readings and so forth) to perform intelligent fault detection and localisation, and predict future faults and service needs. CC Systems develops advanced electronics and control systems for industrial machines and vehicles operating in rough environments. One of their products is a diagnostic platform called Diagnostic Runtime Engine (DRE), supplying the customer with a tool for building a diagnostic system. The platform offers supervision of the control system. Actions are performed when it detects a possible fault or indication of a potential future fault. An action could be for example the creation of an alarm. The DRE, as designed today, only works together with a control system running in an environment called CoDeSys. In this master thesis a new architecture of the platform is presented, with the objective to make the platform compatible with an arbitrary control system. A prototype is implemented to prove the concept of the suggested architecture model. A number of different standard diagnostic blocks, used for building the diagnostic system, are also suggested with the objective to make it easier for the user to employ the DRE. A proposition of how development with the diagnostic platform can proceed beyond this thesis is also presented. / För att maximera drifttid hos en industriell maskin och minimera driftskostnader samt standby- och service-tid, kan ett diagnostiksystem användas. Ett sådant system använder sig av information som redan finns tillgänglig i maskinens styrsystem (så som styrsignaler, tillstånd, sensorvärden och så vidare) för att utföra feldetektering och fellokalisering samt analys av möjliga framtida feltillstånd och servicebehov. CC Systems utvecklar avancerade elektronikkomponenter och styrsystem för industriella maskiner och fordon. En av deras produkter är en diagnostikplattform, Diagnostic Runtime Engine (DRE), som erbjuder ett verktyg för att bygga upp ett diagnostiksystem. Plattformen möjliggör övervakning av styrsystemet, och detektion av ett nuvarande feltillstånd eller möjligt framtida feltillstånd leder till att en handling utförs. En handling kan till exempel vara att ett alarm skapas. Diagnostikplattformen, som den är gjord idag, fungerar bara tillsammans med ett styrsystem som är implementerat i utvecklingsmiljön CoDeSys. I detta examensarbete presenteras en ny arkitektur på plattformen som möjliggör användande tillsammans med ett godtyckligt styrsystem. En prototyp är implementerad för att visa att den föreslagna arkitekturmodellen fungerar i praktiken. Dessutom är ett antal standard-diagnostikblock, som används då ett diagnostiksystem byggs upp, föreslagna. Standardblocken har till syfte att underlätta användandet av diagnostikplattformen. Ett förslag för hur DRE kan byggas om och utvecklas i framtiden är också presenterat.
114

Traction control of an electric vehicle with four in-wheel motors

Hajihosseinlu, Amin January 2015 (has links)
This thesis evaluates an electric vehicle with four independently-controlled in-wheel electric motors. The electric vehicle investigated in this work requires a main con- troller that not only coordinates with each individual motor drive controller, but is also needed to distribute torque and power to each in-wheel motor. The controller adjusts the speed of each motor to the driving conditions according to the require- ments and emulates the behavior of a mechanical di erential. Then, in addition to the electronic di erential controller, a simple yet robust control strategy for maximiz- ing traction force between tire and road is developed and presented. Moreover, the controller continuously senses the yaw rate and prevents over- and under-steering by adjusting the torque on the right or left wheels. Simulation and experimental results validate the proposed strategy.
115

Reduced order modeling of wind turbines in MatLab for grid integration and control studies

Antonelli, Jacopo January 2012 (has links)
The current trend in the wind power industry is to develop wind turbines of constantly increasing size and rated power, as well as wind farms of growing size and installed wind power. A careful study of the behaviour of the wind turbines during their operation is of crucial importance in the planning phase and in the design stage of a wind farm, in order to minimize the risks deriving from a non accurate prediction of their impact in the electric grid causing sensible faults of the system. To analyze the impact of the wind turbines in the system, motivates the development of accurate yet simple models. To be able to practically deal with this topics, a simple model of a wind turbine system is investigated and developed; it has the aim to describe the behaviour of a wind turbine in operation on a mechanical standpoint. The same reduced order simple model can also be employed for control system studies; the control system model that can’t be used in generation, can use the reduced model. Together with the analytical description of such model, is realized a MatLab code to numerically analyse the response of the system, and the results of the simulation through such code are presented. The objective of this thesis has been to provide a simple benchmark tool in MatLab for grid integration and control studies for interested researchers.
116

Distributed Control for Vision-based Convoying

Goi, Hien 19 January 2010 (has links)
This thesis describes the design of a vision-based vehicle-following system that uses only on-board sensors to enable a convoy of follower vehicles to autonomously track the trajectory of a manually-driven lead vehicle. The tracking is done using the novel concept of a constant time delay, where a follower tracks the delayed trajectory of its leader. Two separate controllers, one linearized about a point ahead and the other linearized about a constant-velocity trajectory, were designed and tested in simulations and experiments. The experiments were conducted with full-sized military vehicles on a 1.3 km test track. Successful field trials with one follower for 10 laps and with two followers for 13.5 laps are presented.
117

Distributed Control for Vision-based Convoying

Goi, Hien 19 January 2010 (has links)
This thesis describes the design of a vision-based vehicle-following system that uses only on-board sensors to enable a convoy of follower vehicles to autonomously track the trajectory of a manually-driven lead vehicle. The tracking is done using the novel concept of a constant time delay, where a follower tracks the delayed trajectory of its leader. Two separate controllers, one linearized about a point ahead and the other linearized about a constant-velocity trajectory, were designed and tested in simulations and experiments. The experiments were conducted with full-sized military vehicles on a 1.3 km test track. Successful field trials with one follower for 10 laps and with two followers for 13.5 laps are presented.
118

Motion Control of Rigid Bodies in SE(3)

Roza, Ashton 26 November 2012 (has links)
This thesis investigates the control of motion for a general class of vehicles that rotate and translate in three-space, and are propelled by a thrust vector which has fixed direction in body frame. The thesis addresses the problems of path following and position control. For path following, a feedback linearization controller is presented that makes the vehicle follow an arbitrary closed curve while simultaneously allowing the designer to specify the velocity profile of the vehicle on the path and its heading. For position control, a two-stage approach is presented that decouples position control from attitude control, allowing for a modular design and yielding almost global asymptotic stability of any desired hovering equilibrium. The effectiveness of the proposed method is verified both in simulation and experimentally by means of a hardware-in-the-loop setup emulating a co-axial helicopter.
119

An inclusive account of the general theory and applications of Kalman discrete filter theory

Galles, William Bernard, January 1965 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1965. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 156-166.
120

A new integrated approach for operability analysis of chemical plants

Bahri, Parisa A. January 1995 (has links)
Thesis (Ph. D.)--University of Sydney, 1996. / Title from title screen (viewed on February 3, 2009) Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Dept. of Chemical Engineering. Degree awarded 1996, thesis submitted 1995. Includes bibliographical references. Also issued in print.

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