This thesis work was undertaken to develop a new high level command for an unmanned aerial vehicle. The command is assumed to make the UAV follow a reference position that is placed on a certain distance to an object. At the same time the UAV is assumed to move more smoothly than the reference position and the UAV is allowed to follow the reference position with margin. The problem was solved with an automatic control system that takes the reference position as input signal and has a fictitious position as output signal. The fictitious position moves smoothly inside the margin and irregular behavior of the reference position is smoothed out by the automatic control system. The fictitious position is affected by strong feedback outside the margin and weak feedback inside the margin. This makes the fictitious position to stay inside the margin and moves smoothly inside the margin. The UAV follows the fictitious position instead of the reference position. In this way the UAV holds a certain distance to an object and at the same time moves smoother than the object.

A sliding mode controller is proposed for controlling molten steel level in a mold of continuous casting machine in this thesis. The comparisons of dynamic response, control accuracy, and reaction to perturbation between proposed controller and PID controller currently used are also presented. A perturbation estimator is embedded in the sliding mode controller in order to enhance the robustness against model uncertainty, parameter variation, and external disturbance. The perturbation considered in this thesis includes variation of casting speed, variation of area of slide gate, time delay, variation of mold area, and Dead-Band etc.. In addition, the effects of adjusting the design parameter of the proposed controller on system¡¦s dynamics are also considered.

When controlling the real-time system that is a robotic joint, reliability is the chief concern. Implementing controllers via embedded software imposes several limitations on the controller frequency, such as algorithm latency and supplemental processes (like networking) competing for execution time. If these obstacles prevent a controller from finishing a cycle before its period expires, stability cannot be guaranteed. A developer of embedded software controls ought to be able to prove the timeliness of the controller based on analysis and validation. Otherwise, the choice of controller frequency is arbitrary, without any guarantee of stability in worst-case scenarios. This work realized a truly distributed control system for a humanoid robot by migrating a portion of the joint controller to the low-level. While the central computer is still responsible for determining a joint torque to properly realize whole-body objectives, the low-level processor executes force control locally to produce that torque via a linear actuator. Decoupling the force controller from networking reduced its latency and variability, allowing it to execute several times between receiving desired forces. Furthermore, a real-time operating system was added on top of the existing firmware to enforce and verify timing constraints. Preemptive threading modules within the real-time kernel allow the processor to prioritize controller execution above all other activities, aiding its routine completion. The chosen RTOS provides powerful instrumentation and debugging tools to efficiently verify proper execution and quickly resolve errors. These changes allowed the controller to demonstratively operate at a greater frequency with a full guarantee that timeliness is enforced under all possible circumstances. Verification was performed on a robotic joint test stand to prepare for deployment on a full-scale humanoid robot. / Master of Science / A "control algorithm", or simply "controller", can be made to balance a humanoid robot by taking a snapshot of the robot's pose and motion to calculate how to manipulate each motor to maintain stability. This process repeats many times per second. The precise rate is a design choice termed as the controller's "frequency". While a higher frequency generally yields better performance, too great a frequency means the algorithm cannot finish before it is time to repeat, resulting in malfunction. This work implements tools for developers to observe exactly how long a controller algorithm takes to run. This helps the developer choose a frequency fast enough to maintain robot balance within the computer's capabilities.

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / A ground based intelligent agent and operations network is being created to handle all aspects of spacecraft command and control. This system will have the dual purpose of enabling cost efficient operation of a number of small satellites and serving as a flexible testbed for the validation of space system autonomy strategies. The system is currently being targeted to include over a dozen globally distributed amateur radio ground stations and access to nearly ten spacecraft. The use of distributed computing systems and virtual interaction schemes are significantly contributing to the creation of this system. The Internet is used to link the network's control centers and ground stations. In addition, a World Wide Web (WWW) based user and operator interface is being developed to permit high level goal specification of spacecraft experiments and actions. This paper will describe the operating network being developed, the use of the Internet as an integral part of the system's architecture, the design of the WWW interface, and the future development of the system.

There have been substantial improvements in the area of rehabilitation robotics in the recent past. However, these advances are inaccessible to a large number of people with disabilities who are in most need of such assistance. This group includes people who are in a severely paralyzed state, that they are completely "locked-in" in their own bodies. Such persons usually retain full cognitive abilities, but have no voluntary muscle control. For these persons, a Brain Computer Interface (BCI) is often the only way to communicate with the outside world and/or control an assistive device. One major drawback to BCI devices is their low information transfer rate, which can take as long as 30 seconds to select a single command. This can result in mental fatigue to the user, specially if it necessary to make multiple selections over the BCI to complete a single task. Therefore, P300 based BCI control is not efficient for controlling a assistive robotic device such as a robotic arm. To address this shortcoming, a novel vision based Brain Robot Interface (BRI) is presented in this thesis. This visual user interface allows for selecting an object from an unstructured environment and then performing an action on the selected object using a robotic arm mounted to a power wheelchair. As issuing commands through BCI is slow, this system was designed to allow a user to perform a complete task via a BCI using an autonomous robotic system while issuing as few commands as possible. Furthermore, the new visual interface allows the user to perform the task without losing concentration on the stimuli or the task. In our interface, a scene image is captured by a camera mounted on the wheelchair, from which, a dynamically sized non-uniform stimulus grid is created using edge information. Dynamically sized grids improve object selection efficiency. Oddball paradigm and P300 Event Related Potentials (ERP) are used to select stimuli, where the stimuli being each cell in the grid. Once selected, object segmentation and matching is used to identify the object. Then the user, using BRI, chooses an action to be performed on the object by the wheelchair mounted robotic arm (WMRA). Tests on 8 healthy human subjects validated the functionality of the system. An average accuracy of 85.56% was achieved for stimuli selection over all subjects. With the proposed system, it took the users an average of 5 commands to perform a task on an object. The system will eventually be useful for completely paralyzed or locked-in patients for performing activities of daily living (ADL) tasks.

The theoretical stability analysis of mold level control system for slab continuous casting machine is presented in this thesis. In the procedure of analyzing the stability of the mold level control system, the PLC program written for the control system is studied first in order to obtain the mathematical model of a PID controller. Then the mathematical models of servo-amplifier, servo-valve, electro hydraulic system to the output of mold level are established. A simulative control system using Matlab software is constructed in accordance with these mathematical models so that not only the results of stability analysis can be verified but also the dynamic response of controlled system can be studied. Finally, the effects of some potential disturbance on system¡¦s dynamics, stability, and control accuracy are also analyzed.

Flotation is one part of LKAB's refining process where minerals are separated from iron ore in cascade connected tanks. A good level control in the flotation tanks is vital to get a high recovery of the iron. Nominal and robust performance of different level controllers are compared in the study. Robust performance is analyzed for uncertainties in valve contants and for hysteresis in the valves. The results show that LQG control give better nominal performance than PI control. The robust performance is worse for the LQG controller than the PI controller for modelled uncertainties in valve contants. The robustness analysis shows also that LQG control is less sensitive to hysteresis in the valves compared to PI control. Thus, type of uncertainty affects different control strategies differently. / Flotation är en del av LKAB:s förädlingsprocess där mineraler separeras från järnmalmen i seriekopplade tankar. En god nivåhållning i flotationstankarna är viktigt för att erhålla ett högt järnutbyte. Olika reglerstrategiers nominella och robusta prestanda jämförs i studien. Robust prestanda undersöks vid osäkerhet i ventilkonstanter och hysteres i ventiler. Resultaten visar att LQG-reglering ger bättre nominell prestanda än PI-reglering. Den robusta prestandan vid osäkerhet i ventilkonstanter är sämre för LQG-reglering jämfört med PI-reglering. Robusthetsanalysen visar även att LQG-regulatorn är mindre känslig för hysteres i ventiler än PI-regulatorn. Typen av osäkerhet inverkar sålunda olika på olika reglerstrategier.

The present dynamic manufacturing environment has been characterized by a greater variety of products, shorter life-cycles of products and rapid introduction of new technologies, etc. Recently, a new manufacturing paradigm, i.e. Reconfigurable Manufacturing Systems (RMS), has emerged to address such challenging issues. RMSs are able to adapt themselves to new business conditions timely and economically with a modular design of hardware/software system. Although a lot of research has been conducted in areas related to RMS, very few studies on system-level control for RMS have been reported in literature. However, the rigidity of current manufacturing systems is mainly from their monolithic design of control systems. Some new developments in Information Technology (IT) bring new opportunities to overcome the inflexibility that shadowed control systems for years. Component-based software development gains its popularity in 1990's. However, some well-known drawbacks, such as complexity and poor real-time features counteract its advantages in developing reconfigurable control system. New emerging Extensible Markup Language (XML) and Web Services, which are based on non-proprietary format, can eliminate the interoperability problems that traditional software technologies are incompetent to accomplish. Another new development in IT that affects the manufacturing sector is the advent of agent technology. The characteristics of agent-based systems include autonomous, cooperative, extendible nature that can be advantageous in different shop floor activities. This dissertation presents an innovative control architecture, entitled Component-based Intelligent Control Architecture (CICA), designed for system-level control of RMS. Software components and open-standard integration technologies together are able to provide a reconfigurable software structure, whereas agent-based paradigm can add the reconfigurability into the control logic of CICA. Since an agent-based system cannot guarantee the best global performance, agents in the reference architecture are used to be exception handlers. Some widely neglected problems associated with agent-based system such as communication load and local interest conflicts are also studied. The experimental results reveal the advantage of new agent-based decision making system over the existing methodologies. The proposed control system provides the reconfigurability that lacks in current manufacturing control systems. The CICA control architecture is promising to bring the flexibility in manufacturing systems based on experimental tests performed. / Ph. D.

In recent years, significant progress has been made in improving the performance of unmanned air vehicles in terms of aerodynamic performance, endurance, autonomy, and the capability of on-board sensor packages. UAVs are now a vital part of both military actions and scientific research efforts. One of the newest classes of UAV is the high altitude long endurance or HALE UAV. This thesis considers the high-level control problem for a unique HALE mission involving cooperative solar powered UAVs. Specifically addressed is energy efficient path planning for vehicles that physically link together in flight to form a larger, more energy efficient HALE vehicle. Energy efficient docking is developed for the case of multiple vehicles at high altitude with negligible wind. The analysis considers a vehicle governed by a kinematic motion model with bounded turn rate in planar constant altitude flight. Docking is demonstrated using a platform-in-the-loop simulator which was developed to allow virtual networked vehicles to perform decentralized path planning and estimation of all vehicle states. Vehicle behavior is governed by a status which is commanded by a master computer and communication between vehicles is intermittent depending on each vehicle's assessment of situational awareness. Docking results in a larger vehicle that consumes energy at 21% of the rate of an individual vehicle and increases vehicle range by a factor of three without considering solar recharging. / Master of Science

This thesis deals with the control of blood glucose levels of critically ill patients in intensive care, focusing on hyperglycemia of the critically ill and possible therapy within the competences of nursing and medical staff. The theoretical part of the thesis deals with the issue of hyperglycemia of critically ill patients from the medical and nursing perspective as well as the issues concerning instrumentation. The first chapter describes briefly the history of insulin, relating to its discovery and introduction into practice. The following chapter describes the concepts of critically ill, intensive medicine, intensive care as well as specific nursing care. Short information about etiology, diagnosis, treatment and complications of diabetes mellitus is described in the third chapter. The following are the chapters, which are more specifically devoted to the issue of hyperglycemia of the critically ill, including chapters on glucose homeostasis of the critically ill, the evolution of blood glucose levels, instrument technique, insulin protocols, insulin therapy, details of insulin therapy in intensive care and on the principles of correct blood collection for the determination of blood glucose levels in the conditions of intensive care. The empirical part of this work contains research on the...