This thesis proposes an interactive software tool that can be used to compute complete sets of Proportional Integral Derivative (PID) Controllers from knowledge of the plant transfer function/frequency response data. This is based on research results and algorithms developed by Bhattacharyya and others. Until these research results were published, it was not known if a nominal system could be stabilized using PID Controllers, and current PID Controller designs are carried out using ad hoc tuning rules. By using simulations, engineers can best plan for and observe the stabilizing effect each of the variables has on system performance in a realistic environment. The software application developed calculates and optimizes complete stabilizing sets of PID Controllers for a rational Linear Time Invariant (LTI) system, and has been developed for analytical models of plants with and without time delay. Further, these PID Controller sets are optimized to project subsets simultaneously satisfying multiple performance index specifications. Sets of PID Controllers that stabilize a system are also calculated automatically from knowledge of the frequency response of the plant. It allows the user ease of design and the ability to customize the final solution while permitting full control over source parameters. This thesis includes an introduction to the algorithms that have been developed for plant stabilization, a complete description of the graphical user interface, the simulation of the algorithms performed using LabVIEW, and a summary of future work.

This thesis aims to cover some aspects of synthesis and design of Proportional- Integral-Derivative (PID) controllers. The topics include computer aided design of discrete time controllers, data-based design of discrete PID controllers and data- robust design of PID controllers. These topics are of paramount in control systems literature where a lot of stress is laid upon identification of plant and robust design. The computer aided design of discrete time controllers introduces a Graphical User Interface (GUI) based software. The controllers are: Proportional (P), Proportional-Derivative (PD),Proportional-Integral (PI) and Proportional-Integral- Derivative (PID) controllers. Different performance based design methods with these controllers have been introduced. The user can either explore the performance by interactively choosing controllers one by one from the entire set and visualizing its performance or specify some performance constraints and obtaining the resulting set. In data-based design, the thesis presents a way of designing PID controllers based on input-output data. Thus, the intermediate step of identification of model from data is removed, saving considerable effort. Moreover, the data required is step response data which is easier to obtain in case of discrete time system than frequency response data. Further, a GUI developed for interactive design is also described. In data-robust design, the problem of uncertainty in data is explored. The design method developed finds the stabilizing set which can robustly stabilize the plant with uncertainty. It has been put forward as an application to interval linear programming. The main results of this research include a new way of designing discrete time PID controllers directly from the data. The simulations further confirm the results. Robust design of PID controllers with data uncertainty has also been established. Additionally, as a part of this research, a GUI based software has been developed which is expected to be very beneficial to the designers in manufacturing, aerospace and petrochemical industries. PID controllers are widely used in the industry. Any progress in this field is well acknowledged both in the industry and the academia alike. This thesis attempts a small step further in this direction.

No description available.

Thesis (Ph.D.)--University of Delaware, 2006. / Principal faculty advisor: Jian-Qiao Sun, Dept. of Mechanical Engineering. Includes bibliographical references.

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2006. / Title from title screen (site viewed June 11, 2007). PDF text: x, 153 p. : ill. UMI publication number: AAT 3243742. Includes bibliographical references. Also available in microfilm and microfiche formats.

The attitude determination and control subsystem (ADCS) is a critical part of any satellite conducting scientific experiments that require accurate positioning (such as Earth observation and solar spectroscopy). The engineering design process of this subsystem has a long heritage; yet, it is surrounded by several limitations due to the stringent physical constraints imposed on small satellites. These limitations (e.g., limited computational capabilities, power, and volume) require an improved approach for the purpose of attitude determination (AD) and control. Previous space missions relied mostly on the extended Kalman filter (EKF) to estimate the relative orientation of the spacecraft because it yields an optimal estimator under the assumption that the measurement and process models are white Gaussian processes. However, this filter suffers from several limitations such as a high computational cost. This thesis addresses all the limitations found in small satellites by introducing a computationally efficient algorithm for AD based on a fuzzy inference system with a gradient decent optimization technique to calculate and optimize the bounds of the membership functions. Also, an optimal controller based on a fractional proportional-integral-derivative controller has been implemented to provide an energy-efficient control scheme. The AD algorithm presented in this thesis relies on the residual information of the Earth magnetic field. In contrast to current approaches, the new algorithm is immune to several limitations such as sensitivity to initial conditions and divergence problems. Additionally, its computational cost has been reduced. Simulation results illustrate a higher pointing stability, while maintaining satisfying levels of pointing accuracy and increasing reliability. Moreover, the optimal controller designed provides a shorter time delay, settling time, and steady-state error. This demonstrates that accurate attitude determination and control can be conducted in small spacecraft.

Thesis submitted in compliance with the requirements for the Master's Degree in Technology: Electrical Engineering - Light Current, Durban University of Technology, Department of Electronic Engineering, 2008. / Linear control systems can be easily tuned using classical tuning techniques such as the Ziegler-Nichols and Cohen-Coon tuning formulae. Empirical studies have found that these conventional tuning methods result in an unsatisfactory control performance when they are used for processes experiencing the negative destabilizing effects of strong nonlinearities. It is for this reason that control practitioners often prefer to tune most nonlinear systems using trial and error tuning, or intuitive tuning. A need therefore exists for the development of a suitable tuning technique that is applicable for a wide range of control loops that do not respond satisfactorily to conventional tuning. Emerging technologies such as Swarm Intelligence (SI) have been utilized to solve many non-linear engineering problems. Particle Swarm Optimization (PSO), developed by Eberhart and Kennedy (1995), is a sub-field of SI and was inspired by swarming patterns occurring in nature such as flocking birds. It was observed that each individual exchanges previous experience, hence knowledge of the “best position” attained by an individual becomes globally known. In the study, the problem of identifying the PID controller parameters is considered as an optimization problem. An attempt has been made to determine the PID parameters employing the PSO technique. A wide range of typical process models commonly encountered in industry is used to assess the efficacy of the PSO methodology. Comparisons are made between the PSO technique and other conventional methods using simulations and real-time control. / National Research Foundation

published_or_final_version / Mechanical Engineering / Master / Master of Philosophy

In this thesis, a digital-PID-control single-inductor triple-output (SITO) DC-DC converter is realized in AMS 0.35mum CMOS technology. The size of the chip is about 1600 mum x 1700 mum. To improve load current and reduce cross regulation, a Pre-Sub-Period inductor-current regulation is proposed. Based on the maximum duty cycle limiter, an adaptive inductor current adjustment is realized when the duty cycle of the digital PWM signal is larger than the set maximum duty cycle. By an optimized phase control sequence, the S&H stages of the feedback switching and ADC are controlled to on/off with a minimized delay time. Moreover, the control sequence can virtually remove the setting time. / Multiple voltage supplies are necessary to satisfy the different voltage supply requirements of the different on-chip blocks to reduce power consumption in modem electronic devices, such as the modem embedded systems, the portable devices, personal computing devices and wireless communications and imaging systems. For example, WiMAX transmitter includes different sub-blocks: Baseband processor, IQ modulator and power amplifier. Different blocks should operate with the different power supply voltages to satisfy the different requirements. / Single-input multiple-output DC-DC converter is presented to provide the different voltage supplies and reduce the cost on the elements such as the inductor on PCB and save PCB area. Meanwhile, to remove cross regulation and improve load driving capability, the DC-DC converter should operate in the pseudo-continuous mode/discontinuous mode (P-CCM/DCM). However, in the previous designs, the DC current in the inductor is fixed. When the load becomes heavy enough, cross regulation will significantly affect across the different sub-converters. / Jia, Jingbin. / "December 2009." / Adviser: KaNang Leung Alex. / Source: Dissertation Abstracts International, Volume: 72-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 121-124). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Η διπλωματική εργασία αφορά τον έλεγχο και τη μοντελοποίηση ενός συστήματος τριών δεξαμενών για την ανάμιξη υδατικών διαλυμάτων. Το σύστημα χρησιμοποιεί δύο ανεξάρτητες δεξαμενές αποθήκευσης (tanks) υγρών διαλυμάτων διαφορετικών χρωμάτων. Στόχος της λειτουργίας του συστήματος ελέγχου είναι η επίτευξη καθορισμένης χρωματικής σύνθεσης στα πλαίσια δημιουργίας του τελικού διαλύματος εντός της τρίτης δεξαμενής, η σύνθεση του οποίου καθορίζεται μέσω ενός αισθητήρα φωτεινότητας. Ο αισθητήρας φωτεινότητας «επιστρέφει» κατάλληλα διαμορφωμένο ηλεκτρικό σήμα «ανάλογο» της διερχόμενης φωτεινότητας από το διάλυμα, η οποία εξαρτάται από τη σύνθεση του διαλύματος. Επιπρόσθετα στην επιθυμητή χρωματική σύνθεση, το σύστημα θα πρέπει να λαμβάνει υπόψη του, κατά τη λειτουργία του, προδιαγραφές ελαχίστου – μεγίστου τελικής στάθμης/όγκου για το διάλυμα της σύνθεσης. Τέλος, εκτός του «ανοικτού» συστήματος ανάμιξης, μελετάται η χρήση PID (Proportional – Integral – Derivative) Ελεγκτή με στόχο τη χρονικά δυναμική αντιστάθμιση και προσαρμογή της λειτουργίας του συστήματος σε ενδεχόμενες μεταβολές των υποσυστημάτων, των παραμέτρων ή των διεργασιών του, διασφαλίζοντας μία ευρύτητα συνθηκών ευσταθούς λειτουργίας. / Project concerns the modeling and control of of a three-tank system for mixing liquids. The system uses two independent storage tanks filled with different colors liquid. The aim of the operation of the control system is reaching a specified color in the third tank, the composition of which is determined by a brightness sensor. The brightness sensor 'returns' suitably shaped electrical signal. In addition to the desired color composition, the system should take into account, during operation, specifications minimum - maximum final level / volume for the solution of the composition. Finally, it is studied the use of PID (Proportional - Integral - Derivative) Controller.