Recent experiments are bringing to the fore more and more information about the effects of different treatments on the gene expression of different genes. The results obtained from these experiments show that some definite trends are observed in different genes in the Human Embryonic Kidney and Human Colon Adenocarcinoma Grade II cell lines. The difference in the gene expressions of the two cell lines motivates the problem in this thesis. The thesis provided intervention methods to make the colon cancer cell line genes behave more like their Human Embryonic Kidney cell line counterparts. Two methods of intervention were introduced. The first method was the simpler on-off control intervention while the second method used a more advanced proportional integral control to meet the goal. A comparison of these two intervention methods showed the clear implementational advantages of proportional integral control over on-off control.

In the past decade, the design and manufacturing of intelligent multipurpose underwater vehicles has increased significantly. In the wide range of studies conducted in this field, the flexibility and autonomy of these devices with respect to their intended performance had been widely investigated. This work is related to the design and manufacturing of a small and lightweight autonomous underwater vehicle (AUV) with vision capabilities allowing detecting and contouring obstacles. It is indeed an exciting challenge to build a small and light submarine AUV, while making tradeoffs between performance and minimum available space as well as energy consumption. In fact, due to the ever-increasing in equipment complexity and performance, designers of AUVs are facing the issues of limited size and energy consumption. By using a pair of thrusters capable to rotate 360o on their axis and implementing a mass shifter with a control loop inside the vehicle, this later can efficiently adapt its depth and direction with minimal energy consumption. A prototype was fabricated and successfully tested in real operating conditions (in both pool and ocean). It includes the design and embedding of accurate custom multi-purpose sensors for multi-task operation as well as an enhanced coordinated system between a high-speed processor and accustomed electrical/mechanical parts of the vehicle, to allow automatic controlling its movements. Furthermore, an efficient tracking system was implemented to automatically detect and bypass obstacles. Then, fuzzy-based controllers were coupled to the main AUV processor system to provide the best commands to safely get around obstacles with minimum energy consumption. The fabricated prototype was able to work for a period of three hours with object tracking options and five hours in a safe environment, at a speed of 0.6 m/s at a depth of 8 m.

<p>This report presents the work carried out aiming towardsdistributed control of electric drives through a networkcommunication medium with temporal constraints, i.e, Ethernet.A general analysis on time delayed systems is carried out,using state space representation of systems in the discretetime domain. The effect of input time delays is identified andis used in the preceding controller designs. The main hardwareapplication focused in this study is a Brushless DC servomotor, whose speed control loop is closed via a 10 MbpsSwitched Ethernet network. The speed control loop, which isapproximately a decade slower than the current control loop, isopened and interfaced to the network at the sensor/actuatornode. It is closed at the speed controller end at another nodein the same local area network (LAN) forming a distributedcontrol system (DCS).</p><p>The Proportional Integral (PI) classical controller designtechnique with ample changes in parameter tuning suitable fortime delayed systems is used. Then the standard Smith Predictoris tested, modified with the algebraic design techniqueCoefficient Diagram Method (CDM), which increases the systemdegrees of freedom. Constant control delay is assumed in thelatter designs despite the slight stochastic nature in thetiming data observations. Hence the poor transient performanceof the system is the price for the robustness inherited to thespeed controllers at the design stage. The controllability andobservability of the DCS may be lost, depending on the range inwhich the control delay is varying. However a state feedbackcontroller deploying on-line delay data, obtained by means ofsynchronizing the sensor node and controller node systemclocks, results in an effective compensation scheme for thenetwork induced delays. Hence the full state feedbackcontroller makes he distributed system transient performanceacceptable for servo applications with the help of poleplacement controller design.</p><p>Further, speed synchronizing controllers have been designedsuch that a speed fluctuation caused by a mechanical loadtorque disturbance on one motor is followed effectively by anyother specified motor in the distributed control network with aminimum tracking or synchronizing error. This type ofperformance is often demanded in many industrial applicationssuch as printing, paper, bagging, pick and place and materialcutting.</p><p><b>Keywords:</b>Brushless DC Motor, Control Delay, DistributedMotion Control Systems, Proportional Integral Controller, SmithPredictor, Speed Synchronization, State Feedback Controller,Stochastic Systems, Switched-Ethernet, Synchronizing Error,Time Delayed Systems, Tracking Error</p>

<p>The growing energy demand has caused the interconnected power systems to operate close to their stability limit. As a consequence, poorly damped low-frequency oscillations are becoming a common phenomenon. Such oscillations weaken the system security and if not effectively damped can lead to widespread blackouts. A contemporary solution is the addition of Power System Stabilizers (PSSs) to generators. A relatively recent solution based on the advancements in high-power semiconductors is the Flexible AC Transmission System (FACTS) technology meant for transmission locations. FACTS technology comprises of a multitude of FACTS devices among which the <i>Unified Power Flow Controller (UPFC)</i> possesses a unique capability of providing both power flow and voltage control. Particularly, with a suitable transient control system the UPFC can satisfactorily mitigate power system oscillations.</p> <p>This thesis proposes an adaptive control scheme that supplements an existing Proportional-Integral (PI) UPFC control system in damping power system oscillations. PI control is a well-established theory and a commonly used industrial controller. However, its application in a power system that experiences continuously changing system conditions demands its frequent re-tuning. On the other hand, the proposed scheme is a Self Tuning (ST) controller that automatically adapts to the system changes and thereby provides an optimal control for a wide range of operating scenarios. The proposition of assisting the primary PI control action is unique in its approach since it retains the functionality of the existing PI controllers and also enhances the overall damping performance through an add-on ST control loop.</p> <p>The proposed novel ST scheme consists of a Constrained Recursive Least Squares (CRLS) identifier that tracks system parameters recursively and a self-tuning Pole Shift (PS) controller that works on the identified system model to generate a robust control output. Also, to effectively smoothen out the rapid variations of identified system parameters and consequent ringing of control output during large disturbances, the thesis specifies the replacement of the standard-RLS identifier with a "constrained" RLS (CRLS) identifier. The damping enhancement achieved by the proposed controller has been verified through time-domain simulations. The test results clearly depict that the proposed add-on scheme not only enhances the overall damping but is also robust with respect to power flow level, fault type and location. Its inherent flexibility and the positive test results suggest that with little modification, it can be easily applied to other FACTS devices currently incorporated in transmission networks.</p>

As time goes by rapid development of 3D graphics technique and 3C portable product output, 3D graphics have been widely applied to handheld devices, such as notebooks, PDAs, and smart cellular phones. Generally, to process 3D graphics applications in mobile devices, processor needs strong capability of handling large computational-intensive workloads. Complex computation consumes a great quantity of electric power. But the lifetime of handheld device battery is limited. Therefore, the cost, to satisfy this demand, will be shortening the supply time of device battery. Moreover, Moore¡¦ law said that the number of transistors in a chip is double in every eighteen months. But these days the advance in manufacturing batteries still cannot get up with the advance in developing processors. In addition, the improvement of chip size has led to more small, supply voltage of kernel processor in portable device. Considering system efficiency and battery lifetime simultaneously increase the difficulty of designing power management scheme. So, how to manage power effectively has become one of the important key for designing handheld products. For 3D graphics system, dynamic voltage and frequency scaling (DVFS) is one of good solutions to implement power management policy. DVFS needs an efficient online prediction method to predict the workload of frames and then appropriately adjust voltage and frequency for saving energy consumption. Consequently, a lot of related papers have proposed different prediction policy to predict the executing workload of 3D graphics system. For instance, the existing prediction policies include signature-based[1], history-based[3] and proportion-integral-derivative (PID)[14] methods, but most of designers put power management in software, i.e. processors. This solution not only slows power management to get the information about executing time of graphic processing unit (GPU), but also increases the operating overhead of CPU in handheld system. In this paper, we propose a power management workload prediction scheme with a framework of using proportion-integral (PI) controller to be a master controller and fuzzy controller to be a slave controller, and then implement it into hardware circuit. Taking advantage of fuzzy conception in fuzzy controller is to adjust the proportional parameter in PI controller, the shortage of traditional PI controller that demands on complicated try-and-error method to look for a good proportional and integral parameters can be avoided so that the adaption and forecasting accuracy can be improved. Besides, Uniform Window-size Predictor 1 (UW1) is also implemented as an assistant manner. Using UW1 predictor appropriately can improve the prediction trend to catch up with the trend of real workload. Experimental results show that our predictor improves prediction accuracy about 3.8% on average and saves about 0.02% more energy compared with PI predictor[18]. Circuit area and power consumption only increases 6.8% percent and 1.4% compared with PI predictor. Besides, we also apply our predictor to the 3D first person game, Quake II, in the market. The result shows that our predictor is indeed an effective prediction policy. The adaption can put up with the intense workload variation of real game and adjust voltage and frequency precisely to decrease power consumption and meet the purpose of energy saving.

Due to the prevalence of pulse encoders for system state information, an all-digital proportional-integral-derivative (ADPID) is proposed as an alternative to traditional analog and digital PID controllers. The basic concept of an ADPID stems from the use of pulse-width-modulation (PWM) control signals for continuous-time dynamical systems, in that the controllers proportional, integral and derivative actions are converted into pulses by means of standard up-down digital counters and other digital logic devices. An ADPID eliminates the need for analog-digital and digital-analog conversion, which can be costly and may introduce error and delay into the system. In the proposed ADPID, the unaltered output from a pulse encoder attached to the systems output can be interpreted directly. After defining a pulse train to represent the desired output of the encoder, an error signal is formed then processed by the ADPID. The resulting ADPID output or control signal is in PWM format, and can be fed directly into the target system without digital-to-analog conversion. In addition to proposing an architecture for the ADPID, rules are presented to enable control engineers to design ADPIDs for a variety of applications.

This report presents the work carried out aiming towardsdistributed control of electric drives through a networkcommunication medium with temporal constraints, i.e, Ethernet.A general analysis on time delayed systems is carried out,using state space representation of systems in the discretetime domain. The effect of input time delays is identified andis used in the preceding controller designs. The main hardwareapplication focused in this study is a Brushless DC servomotor, whose speed control loop is closed via a 10 MbpsSwitched Ethernet network. The speed control loop, which isapproximately a decade slower than the current control loop, isopened and interfaced to the network at the sensor/actuatornode. It is closed at the speed controller end at another nodein the same local area network (LAN) forming a distributedcontrol system (DCS). The Proportional Integral (PI) classical controller designtechnique with ample changes in parameter tuning suitable fortime delayed systems is used. Then the standard Smith Predictoris tested, modified with the algebraic design techniqueCoefficient Diagram Method (CDM), which increases the systemdegrees of freedom. Constant control delay is assumed in thelatter designs despite the slight stochastic nature in thetiming data observations. Hence the poor transient performanceof the system is the price for the robustness inherited to thespeed controllers at the design stage. The controllability andobservability of the DCS may be lost, depending on the range inwhich the control delay is varying. However a state feedbackcontroller deploying on-line delay data, obtained by means ofsynchronizing the sensor node and controller node systemclocks, results in an effective compensation scheme for thenetwork induced delays. Hence the full state feedbackcontroller makes he distributed system transient performanceacceptable for servo applications with the help of poleplacement controller design. Further, speed synchronizing controllers have been designedsuch that a speed fluctuation caused by a mechanical loadtorque disturbance on one motor is followed effectively by anyother specified motor in the distributed control network with aminimum tracking or synchronizing error. This type ofperformance is often demanded in many industrial applicationssuch as printing, paper, bagging, pick and place and materialcutting. <b>Keywords:</b>Brushless DC Motor, Control Delay, DistributedMotion Control Systems, Proportional Integral Controller, SmithPredictor, Speed Synchronization, State Feedback Controller,Stochastic Systems, Switched-Ethernet, Synchronizing Error,Time Delayed Systems, Tracking Error / NR 20140805

Electro-Hydraulic (EH) systems are commonly used in the industry for applications that require high power-weight ratios and large driving forces. The EH system studied in this master thesis have recently been upgraded with new hardware components and as a part of this upgrade a new controller was requested. The system consists of a controller that computes a control signal for an electric motor. The motor drives a gear pump that generates a flow of hydraulic fluid. The flow is then directed to a cylinder. The movements of a piston in the cylinder is affected by the flow and the piston position can be measured. The measured piston position is then fed back to the controller and the control loop is complete. The system was previously controlled using a Proportional-Integral-Derivative (PID) controller and the purpose of this thesis is to compare the old controller with alternative control strategies suitable for this application. The evaluation of the controllers is based on both software and hardware simulations and results in a recommendation for final implementation of the best suited controller. The control strategies chosen for investigation are: a retuned PID controller, a PID controller with feed forward from reference, a PID based cascade controller, a Linear Quadratic (LQ) controller, and a Model Predictive Controller (MPC). To synthesize the controllers an approximate model of the system is formed and implemented in the software environment Matlab Simulink. The model is tuned to fit recorded data and provides a decent estimation of the actual system. The proposed control strategies are then simulated and evaluated in Simulink with the model posing as the real system. These simulations resulted in the elimination of the cascade controller as a possible candidate since it proved unstable for large steps in the reference signal. The remaining four controllers were all selected for simulation on the real hardware system. Unfortunately the MPC was never successfully implemented on the hardware due to some unknown compatibility error and hence eliminated as a possible candidate. The three remaining control strategies, PID, PID with feed forward from reference and the LQ controller, were all successfully implemented and simulated on hardware. The results from the hardware simulations compared to simulations made with the old controller, as well as the results from the software simulations, were then evaluated. Depending on the purpose one of two control strategies is recommended for this application. The LQ controller achieved the best overall performance and is presented as the control strategy best suited for this application.

In order to have an interception with a target, a missile should be guided with a successful guidance algorithm accompanied with a suitable autopilot structure. In this study, different autopilot and guidance designs for a canard-controlled missile are developed. As a first step, nonlinear missile mathematical model is derived by using the equations of motion with aerodynamic coefficients found by Missile DATCOM program. Autopilot design starts by the linearization of the nonlinear missile model around equilibrium flight conditions. Controllers based on the concepts of optimal control theory results and sliding mode control are designed. In all of the designs, angle of attack command and roll angle command type autopilot structures are used. During the design process, variations in angle of attack, Mach number and altitude can lead to significant performance degradation. This problem is typically solved by applying gain-scheduling methodology according to these parameters. There are different types of guidance methods in the literature. Throughout this study, proportional navigation guidance and its modified forms are selected as a base algorithm in the guidance system design. Other robust forms of guidance methods, such as an optimal guidance approach and sliding mode guidance, are also formed for performance comparison with traditional proportional navigation guidance approach. Finally, a new guidance method, optimal proportional-integral guidance, whose performance is the best among all of the methods included in the thesis against highly maneuvering targets, is introduced.

The purpose of this thesis is to investigate different control strategies on a differential drive vehicle. The vehicle should be able to drive in turns at high speed and slowly when it should park next to a charger. In both these cases, good precision in both orientation and distance to the path is important. A PID and an LQ controller have been implemented for this purpose. The two controllers were first implemented in a simulation environment. After implementing the controllers on the system itself, tests to evaluate the controllers were made to imitate real-life situations. This includes tests regarding driving with different speeds in different turns, tests with load distributions, and tests with stopping accuracy. The existing controller on the system was also tested and compared to the new controllers. After evaluating the controllers, it was stated that the existing controller was the most robust. It was not affected much by the load distribution compared to the new controllers. However, the LQ controller was slightly better in most cases, even though it was highly affected by the load distribution. The PID controller performed best regarding stopping accuracy but was the least robust controller by the three. Since the existing controller has a similar performance as the LQ controller but is more robust, the existing controller was chosen as the best one.