Computer Control addresses the design of algorithms implemented in a computer. The implementation of the digital control program should ensure the accuracy, speed and robustness necessary for the regulation of a process variable (industrial, domestic, cyber, etc.).



In this subject, methods and techniques for modelling, analysis and design of controllers discrete systems, and its implementation through the use of computers in this discipline are introduced. the study of normal control systems in the industry and the most common features in PID controllers and industrial networks advance and phase delay is made.



- Prerequisites: no specified enrolment restrictions with other subjects of the curriculum.

- Other requirements: previous basic knowledge needed to follow the course of the subject, are those acquired in the subjects of Mathematics, Physics and Automation and Control (especially the concepts of transfer function, frequency response and diagrams block).

The specific competences of the subject “Computer Control” are developed in the context of the transversal and general competences of the Degree in Industrial Technology, and more specifically in the following competences of the module M04-Electives:



OP3.-Ability to address developments, projects and advanced studies in the field of automatic regulation, industrial electronics and its application to industrial automation, with a high degree of autonomy.



OP7.-Search and select information, communicate it orally or in writing, write reports and projects, manage the documentation.





LEARNING OUTCOMES



The learning outcomes after having completed the subject “Computer Control” are synthesized in:



>> Being able to choose the digital control sampling frequency for each application.

>> Knowing how to obtain the equivalent discrete model of a continuous process to be controlled.

>> Knowing how to analyse the stability of a digital control system, and to determine its expected robustness in terms of stability margins.

>> To know how to choose the most appropriate control structure, and design it on the basis of closed loop specifications.

>> To know how to specify the digital controller by means of its difference equations, and to know how to program them in a controller device.

>> To know how to tune a discrete PID controller by means of measurement-based techniques and model-based techniques.

THEORETICAL CONTENT



DISCRETE TIME SYSTEMS



Topic 1 Introduction. The computer as a control element

Elementary loop computer control.

Computer functions. Computer control schemes.



Topic 2 Hardware for Control Applications.



Topic 3 discrete signals and systems

Sequence. Sequence properties.

Representation of discrete-time systems: difference equation, discrete convolution.

Stability of a discrete system.



Topic 4 Z-transform

Definition. Properties.

Z-transform elementary functions.

Inverse Z-transform. Definition. Methods.



Topic 5 Sampling and Reconstruction

Sampling by impulses.

Properties of the sampled signal. Sampling theorem.

Reconstruction. Reconstruction by retainers.



Topic 6 Sampled Systems

Pulse transfer function.

Transfer function of the sampled signal by pulses.

Transfer function z Systems open loop and closed loop.

Z transfer function of a control system computer.



ANALYSIS OF DISCRETE TIME SYSTEMS



Topic 7 Relationship between the plane and the plane z.

Transformation from S plane to the z plane.

Constant damping and constant natural frequency locations.



Topic 8 Stability

Stability Analysis.

Jury criterion.

Effect of the sampling period in system stability



Topic 9 Dynamic Analysis.

First order systems and 2nd order.



Topic 10 Accuracy

Analysis steady.

Precision. Steady-state error.

Effects of disturbances.



DESIGNING DISCRETE-TIME CONTROL SYSTEMS



Topic 11 Discretization of Continuous Regulators

Discretization methods by numerical integration.

Discretization of the PID controller.



Topic 12 Design of Regulators in the z-plane

Root locus method

Dominant pole assigning method



Topic 13 PID Controllers



Topic 14 Frequency Response Methods

Design of Regulators in the z-plane: Frequency Response Method.

Bode plot.

Compensator design.



Topic 15 Direct Synthesis Methods

Pole placement controllers.

Drivers cancellation. Minimum drivers and drivers finite time period.

Kalman and Dahlin controllers







LABORATORY AND SEMINAR CONTENT





1- Analysis and simulation tools: Matlab and Simulink

2- Signals and discrete systems: computational methods

3- Root locus design: Sisotool

4- Effect of sampling period

5- PID control: continuous and discrete.

6- Servomotor control system: Monitoring and Characterization. Control system design. Direct control of the servomotor.

7- Design of discrete controllers.

8- Presentations: Design of discrete controllers and Trends in Computer Control .

The theoretical content will be presented in face-to-face lectures based on reference materials and texts.

These materials and texts are accessible to students through the eGela platform http://egela.ehu.es, and in the School's library.



The students will have at their disposal through eGela:

1) documents related to the contents of the subject (presentations, problem statements and answers, and links of interest on the Internet).



2) Statements and Assignments of the practical sessions of Laboratory and Seminar.



The theoretical concepts presented will be applied to the resolution of practical problems. These will be worked in the seminars where the students meet in small groups with the teacher to solve problems, facilitating the collective analysis of these problems. For these sessions the students will work initially individually and later in pairs, using the documentation related to the problem statements and answers.



In the laboratory classes, students will perform control practices using computational methods offered by software tools such as Matlab and Simulink (high-level language environment and interactive environment). This will complement and reinforce the control concepts and techniques described in the theory classes. For these sessions the students will work in pairs with another student from the course, and will use a computer, internet, and the servomotor mock-ups. The documentation for this

• Continuous Assessment System
• Final Assessment System
• Tools and qualification percentages:
  • Written test to be taken (%): 70
  • Completion of labs, team work, presentations and portfolio. (%): 30

ORDINARY CONVOCATION

The evaluation of this course is continuous, being 70% associated with a single final exam and 30% associated with the work to be done by the students during the course in the laboratory and seminar sessions.



The correspondence between the evaluation tools and the types of evaluation are:



- Final Written Test (70%): It will be held on the official date set by the center for the test associated with the ordinary call. It will evaluate the theoretical and practical knowledge covered throughout the course by means of different types of questions (test, open answers and problems).



- Continuous evaluation of laboratories and seminars throughout the course (30%): It is worked during the laboratory and seminar sessions distributed throughout the weeks of the course. For its evaluation, the quality of the results and the portfolio of the practical and seminar reports will be taken into account.



In order to pass the course in the ordinary call, a total score equal to or higher than 5 points must be reached through the indicated instruments, being mandatory to obtain 50% in the final written test and 50% in the continuous evaluation of laboratories and seminars of the course. In case of not reaching it, the grade that will appear in the minutes will be the grade obtained in the test whose minimum has not been passed (out of 10).



- Waiver of the continuous evaluation in the ordinary exams



As it is reflected in the Regulations of management for the degree courses and first and second cycle), the students will have the right to renounce to the continuous evaluation system. This waiver must be made by formalizing the written "renuncia_evaluacion_continuacion_continua.pdf" document and delivering it to the Secretary's Office of the Department of Systems Engineering and Automation within a maximum period of 9 weeks from the beginning of the course, taking into account the academic calendar of the center.



Those students who waive the continuous evaluation must prove the achievement of knowledge and competences through a written test (70% of the final grade) and a complementary test (30% of the final grade).



The complementary test may be written and/or carried out in the laboratory and will deal with the problems and concepts worked during the Laboratory and/or Seminar sessions.



This structure will be maintained both in the ordinary and extraordinary exams.



WAIVER OF THE EXAM



If the student waives a convocation, the grade that will appear in the minutes will be that of “not-attended”. It will be sufficient not to attend the written test at the official time and date established by the school for that test.

The final grade in the extraordinary call will be made through a series of tests that will evaluate all the concepts (theoretical and practical) of the course.



The structure of the tests will be similar to that of the ordinary call, consisting of a final written test (70% of the final grade) and the continuous evaluation of laboratories and seminars (30% of the final grade) or, failing that, a complementary test (30% of the final grade).



- Students who have not waived the continuous evaluation may keep the grade corresponding to the continuous evaluation (30% of the final grade) and not take the complementary test. The final grade will be calculated, therefore, by adding the result of the final written test of the extraordinary exam (70% of the final grade) to the grade of the continuous evaluation (30%). This will be the default method applied.



- Students who have waived the continuous evaluation must take, in addition to the final written test (70% of the final grade), the complementary test (30% of the final grade).



- The complementary test may be written and/or carried out in the laboratory and will deal with the problems and concepts worked on during the laboratory and/or seminar sessions.



In order to pass the course in the extraordinary call, a total score equal to or higher than 5 points must be obtained through the evaluation instruments previously indicated, being mandatory to obtain 50% in the final written test and 50% in the continuous evaluation or in the complementary test. In case of not reaching it, the grade that will appear in the minutes will be the grade obtained in the test whose minimum has not been passed (out of 10).



WAIVER OF THE EXAM



In the case of waiving a convocation, the grade that will appear in the minutes will be that of no-show. It will be sufficient not to attend the written test at the official time and date established by the school for that test.

The documentation corresponding to the transparencies to support the theory, seminars and laboratory can be found in the virtual classroom of the course.

In the laboratory the students will be provided with the necessary computer material (software) and Hw for the elaboration of the different works:
- Matlab/Simulink
- Servomotor model

Basic bibliography

Sistemas de Control en Tiempo Discreto. K. Ogata. Prentice Hall, 2ª Ed 1996

Sistemas de Control Digital. Kuo, B.C. ED CECSA.

Sistema de Control contínuos y discretos – John Dorsey. McGraw Hill 2005

Diseño Algebraico de Controladores Discretos. Berbabeu Soler and Martínez Iranzo. Ed, UPC

In-depth bibliography

Digital Control Systems. Paraskevopoulos P.N. Ed Prentice Hall
Digital Control Systems. Analysis and Design.. Nagle, Philips. ED Prentice Hall
Microcontroller Based Applied Digital Control. Ibrahim Dogan. ED Wiley.
Digital Control of Dynamic Systems. Franklin, Powell and Workman. Addison Wesley.
Digital Control K.M.Moudgalya. Wiley 2007
Discrete-Time Control Problems. J.H.Chow et ad. Thoomson 2003
Digital Control Engineering. M. Sam Fadali. Academic Press, 2009.

Journals

Control Engineering Practice. A Journal of IFAC, the International Federation of Automatic Control.
Automática e Instrumentación. Editorial: Grupo TecniPublicaciones
Revista Iberoamericana de Informática Industrial

Web addresses

International Federation of Automatic Control http://www.ifac-control.org/
Comité Español de Automática de la IFAC. http://www.cea-ifac.es/
American Automatic Control Council. http://www.a2c2.org/
The International Society for Measurement and Control. http://www.isa.org/
The Institute of Measurement and Control. http://www.instmc.org.uk/
The IEEE Control Systems Society. http://www.ieeecss.org/
Control Tutorials for MATLAB and Simulink http://ctms.engin.umich.edu/CTMS/index.php?aux=Home