Automatics A - LModule Automatic Control
Academic Year 2023/2024 - Teacher: Paolo Pietro ARENAExpected Learning Outcomes
The course aims at reaching the following objectives, according to the Dublin descriptors:
1. Knowledge and understanding: at the end of the course the sthudents will :
- understand the basics of retroactive control of a linear dynamic system, continuous time and discrete time;
- analyze the stability of closed-loop systems produced by external disturbances or parametric variations;
- know the specifications of a control system, both in the time and frequency domain;
2. Applying knowledge and understanding: at the end of the course the students will be able to:
- perform the design of a feedback control systems for a linear time-invariant continuous-time system and
performing its discrete-time realization;
- carry out the project using standard PID type controllers
3. Making judgements: students will be able to judge the potential and limits of the control of Linear and Time-
Invariant Systems (LTI).
4. Communication skills: students will be able to illustrate the basic aspects of LTI Systems, interact and
collaborate as a team with other experts in the field of control.
5. Learning skills: students will be able to autonomously extend their knowledge on the Theory of Control of LTI
Systems, drawing on the vast literature available in the field.
Course Structure
Lessons will be mainlyfrontal; sometimes personal computer will be used to maximise learning objectives. It will also be used to make numerical exercises and simulations.
During exercitations some students will be asked to actively participate together wiith the professor, at the aim to stimulte attention and to perform a "sample check" of the real state of the learning status
Should teaching be carried out in mixed mode or remotely, it may be necessary to introduce changes with
respect to previous statements, in line with the programme planned and outlined in the syllabus.
Attendance of Lessons
Students have not to attend the lessons mandatorily. Regular attendance at lectures and exercises is however strongly recommended for
achievement of the expected training objectives on schedule.Detailed Course Content
1. Introduction to control systems; Characteristics of the response for linear systems of the first and the second order in the time domain: time constant, response time, rising time, settling time. relation between the response characteristics and the pole-zero position in the s plane. Characteristics of the frequency response for first and second order systems, cut-off frequency, band, resonance modulus. Non minimum phase systems. Polar plots.
2. Open and closed loop control. feedback influence on the sensitivity to parameter variations, disturbance both in the direct chain and in the feedback path, and to the band width for a linear system. Steady state accuracy for a feedback system for input signals like step, ramp, parabolic ramp; classification of control systems in "types". Stability analysis via the Nyquist criterion. Gain and Phase margins. Root locus: drawing rules and examples.
3. Performances of a control system: static and dynamic performances. Transformation of time domain to frequency domain performances. Frequency response design using lead and lag elementary controller network using Bode diagrams. Root locus design. realization of controller networks via operational amplifiers. Standard PID controllers: empirical and analytical tuning strategies.
4. realization of controller networks via operational amplifiers. Standard PID controllers: empirical and analytical tuning strategies.
5. Relation between the s plane and the z plane. Bilinear transformation. Discretization and reconstruction of a signal. Sampling theorem. Performances of a discrete control system. Design of a discrete control system via translation of a continuous controller.
6. Exercitations. The practical lessons are focussed ad deepening of theoretical aspects using key exercises, using the Matlab tool. particular examples are related to the frequency response design and root locus design.
Textbook Information
1. Norman Nise, Controlli Automatici,,CittàStudi;
2. Dorf, Bishop, Controlli Automatici, Pearson
Course Planning
| Subjects | Text References | |
|---|---|---|
| 1 | Introduzione ai sistemi di controllo; performance della risposta di sistemi lineari del primo e secondo ordine nel dominio del tempo: costanti di tempo, tempo di risposta, tempo di salita, tempo di assestamento. | Libro di testo 1: capp.1-4 Dispense |
| 2 | Dipendenza delle caratteristiche della risposta dalla posizione dei poli del sistema nel piano s. Caratteristiche della risposta in frequenza di sistemi del primo e del secondo ordine, pulsazione di attraversamento, banda passante, modulo alla risonanza. | Libro di testo 1: capp.1-4 Dispense |
| 3 | Diagrammi polari. Controllo a catena aperta e a catena chiusa. Effetto della retroazione sulla sensitività' alle variazioni parametriche, sui disturbi in catena diretta ed in catena di retroazione e sulla banda passante di un sistema lineare. | Libro di testo 1: cap.10 Dispense |
| 4 | Accuratezza a regime di un sistema retroazionato per ingressi a gradino, a rampa, a parabola, classificazione dei sistemi di controllo a controreazione in tipi. | Libro di testo 1: cap.10 Dispense |
| 5 | Analisi della stabilita' dei sistemi lineari retroazionati mediante il criterio di Nyquist. Margine di fase e di guadagno. | Libro di testo 1: cap.10 Dispense |
| 6 | Metodo del luogo delle radici - Regole di tracciamento ed esempi. | Libro di testo; cap.10 Dispense del docente |
| 7 | Specifiche di un sistema di controllo: specifiche statiche e dinamiche. Trasformazione di specifiche nel dominio del tempo in specifiche sulla risposta armonica. Carta di Nichols. | Libro di testo 1: capp.8-10-11 Dispense |
| 8 | intesi per tentativi. Reti compensatrici elementari: reti anticipatrici e reti attenuatrici. Sintesi per tentativi per compensazione della risposta in frequenza. | dispense del docente |
| 9 | Sintesi con l'ausilio del luogo delle radici. | Libro di testo 1: capp.8-10-11 Dispense |
| 10 | Realizzazione di reti compensatrici tramite sia reti elettriche passive che amplificatori operazionali. | Libro di testo 2; dispense |
| 11 | Controllori standard di tipo PID: metodi di taratura empirici, metodi analitici di taratura. | Libro di testo 1: cap.9 Dispense |
| 12 | Relazione tra il piano Z ed il piano S. Discretizzazione e ricostruzione. Teorema di Shannon. Specifiche di un sistema di controllo nel discreto. | Libro di testo 1: capp.11 Dispense |
Learning Assessment
Learning Assessment Procedures
This module includes two ongoing tests (prove in itinere), each one with a score of up to 15 points. Students who gain an overall score greater than or equal to
18 can avoid performing the Automatic Control part of the Automatica written test, limited to the summer session exams.
The exams at the end of the course refer to the entire "Automatica" subject.
These include a written and an oral test. The written test will consist of a task divided into two parts:
one related to Systems Theory (max. 15 points), the other to Automatic Controls (max 15 points), each consisting of exercises and questions.
Students will have direct access to the oral exam if they have accumulated a score greater than or equal to 18.