Automatics M - ZModule Automatic Control
Academic Year 2023/2024 - Teacher: Giuseppe NUNNARIExpected Learning Outcomes
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
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
- perform control of a nonlinear system using the linearization method.
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
- Teaching will be done through lectures and using, when necessary, the video-projector and software programs for the simulation of dynamic and control systems. This will serve to reinforce the concepts presented during the lectures.
- 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.
Required Prerequisites
Having followed the Systems Theory module provided in the first module of the Automatica course
Complex number algebra; linear differential equations; matrix algebra;
Attendance of Lessons
Detailed Course Content
Module 1 Introduction to control systems; response performance of linear systems of the first and second order in the time domain: time constants, response time, time of
climb, settling time. Dependence of the characteristics of the response on the position of the system poles in the plane s. Characteristics of the frequency response of systems of the first and of the
second order, crossing pulsation, pass band, resonance module. Non-minimum phase systems. Polar diagrams. (Teaching hours: 9)
Module 2 Open and closed chain control. Effect of feedback on sensitivity to parametric variations, on chain and feedback chain disturbances and on the band
pass of a linear system. Accuracy at steady state of a feedback system for step, ramp, parabolic entrances, classification of feedback control systems in types. Analysis
of the stability of linear systems fed back by the Nyquist criterion. Phase and earning margin. Root site method - Tracking rules and examples. (Teaching hours: 12)
Module 3 Specifications of a control system: static and dynamic specifications. Transformation of time-specific specifications into harmonic response specifications. Nichols Charter. Synthesis for
attempts. Elementary compensating networks: anticipatory networks and attenuating networks. Synthesis by trial and error for compensation of frequency response. Synthesis with the help of the place of the roots. (Hours of
teaching: 12)
Module 4 Realization of compensating networks through both passive electrical networks and operational amplifiers. Standard PID type controllers: empirical calibration methods, analytical methods of calibration. (Teaching hours: 6)
Module 5 Relationship between the z-plane and the s-plane. Discretization and reconstruction. Shannon theorem. Specifications of a discrete control system. Design of a control system
discreet. Synthesis of the discrete controller for translation. (Teaching hours: 5)
Module 6. Exercises with the help of the Matlab code (Teaching hours: 6)
Textbook Information
1. Norman Nise, Controlli Automatici, CittàStudi;
2. Dorf, Bishop, Controlli Automatici, Pearson
Course Planning
| Subjects | Text References | |
|---|---|---|
| 1 | 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 | 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 | 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 | 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 | 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 | 6 Metodo del luogo delle radici - Regole di tracciamento ed esempi. | Libro di testo; cap.10 Dispense del docente |
| 7 | 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 | 8* Sintesi per tentativi. Reti compensatrici elementari: reti anticipatrici e reti attenuatrici. Sintesi per tentativi per compensazione della risposta in frequenza. | dispense del docente |
| 9 | 9 Sintesi con l'ausilio del luogo delle radici. | Libro di testo 1: capp.8-10-11 Dispense |
| 10 | 10 Realizzazione di reti compensatrici tramite sia reti elettriche passive che amplificatori operazionali. | Libro di testo 2; dispense |
| 11 | 11* Controllori standard di tipo PID: metodi di taratura empirici, metodi analitici di taratura. | Libro di testo 1: cap.9 Dispense |
| 12 | 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 |
| 13 | * Conoscenze minime irrinunciabili per il superamento dell'esame. N.B. La conoscenza degli argomenti contrassegnati con l'asterisco è condizione necessaria ma non sufficiente per il superamento dell'esame. Rispondere in maniera sufficiente o anche più che sufficiente alle domande su tali argomenti non assicura, pertanto, il superamento dell'esame. |
Learning Assessment
Learning Assessment Procedures
There will be two ongoing tests, each with a score of up to 15 points. Students who accumulate an overall score greater than or equal to 18 can avoid performing the part of Automatic Controls within the written assignment of Automatica, limited to the summer session exams.
The exams at the end of the course refer to the entire Automatica course topics. 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, the other to Automatic Controls, each consisting of exercises and questions, with an overall score of 15 points each. The student will have access to the oral exam if he has accumulated a score greater than or equal to 18. To pass the exam with the minimum score of 18/30, the student must demonstrate that he is able to represent and analyze the structural properties of an LTI system and design a feedback controller with at least one of the techniques discussed in the course.
Verification of learning can also be carried out electronically, should the conditions require it.
To ensure equal opportunities and in compliance with current laws, interested students may request a personal interview in order to plan any compensatory and/or dispensatory measures based on educational objectives and specific needs. Students can also contact the CInAP (Centro per l’integrazione Attiva e Partecipata - Servizi per le Disabilità e/o i DSA) referring teacher within their department.
Examples of frequently asked questions and / or exercises
The texts of the assignments assigned during the various sessions will be available for download on the website dedicated to the course for registered students. They consist of exercises of exercises to be carried out that explore all the main topics of the course. As far as the oral exam is concerned, it primarily concerns the discussion of the written paper. During this discussion, the teacher asks questions such as:
Explain what is meant by a control system.
Explain the advantages and disadvantages of feedback control systems versus open loop control systems.
How is the stability of a feedback system analyzed?
State the Nyquist stability criterion.
What is and how is the place of the roots traced?
What are the main specifications of a control system?
How do the specifications of a control system change from the time domain to the frequency domain?
Expose the method of synthesis by attempts in frequency.
Expose the direct synthesis method.
Expose the method of synthesis by trial and error by means of the root locus.
Expose the analytical calibration method of standard PID type controllers.
Expose the main empirical calibration methods for PID type controllers.
What is meant by digital control system
How to translate an analog controller into digital form.
Explain how to design a digital controller by operating in the domain of the z variable.
Explain how to design a flat response, minimal response time digital controller.