Learning objectives
The first module of Automation Systems aims at studying and solving the main problems concerning the interfacing between control systems and production processes. Part of the course is dedicated to the study of PLC systems.
Course unit content
- Course introduction (1 hour)
The basic elements of control systems: plant, sensors, actuators, and controllers. Problems correlated to the signals' acquisition and conditioning.
- Relevance of the disturbances on the signals' acquisition (1 hour)
The ground loop problem. The isolation amplifiers. Techniques for the reduction of disturbances related to the signals' transmission: shielded cables and twisted pairs. Signals' transmission through unipolar or bipolar connections.
- Acquisition with resistive sensors (2 hours)
Design, problems and use of the Wheatstone bridge for the acquisition of signals from resistive sensors.
- Conditioning circuits based on operational amplifiers (4 hours)
The operational amplifier, the differential amplifier, the instrumentation amplifier: circuit design and analysis of related problems and non-ideality. Basic circuits for the signal conditioning: inverting amplifier, non-inverting amplifier, adder, current-voltage converter, voltage-current converter, integrator.
- Thermal sensors (2 hours)
Resistance Temperature Detectors (RTD) , thermistors, thermocouples: analysis of the components, design of the acquisition system and related problems.
- Stress sensors (2 hours)
Strain gauges: analysis of the components, design of the acquisition system and related problems.
- Position sensors (1 hour)
Encoders, resolvers, inductosyns: analysis of the components and acquisition systems.
- The PID controller(1 hour)
Tuning techniques for the PID controllers.
- Control systems based on PLCs (8 hours)
Generalities. Basic programming techniques for PLC systems.
Bibliography
G. Magnani, G. Ferretti, P. Rocco, “Tecnologie dei sistemi di controllo” – Ed.
McGraw-Hill - II Edizione
C. D. Johnson, "Process control instrumentation technology" - Ed. Prentice Hall - VIII Edition
“Regolazione PID” di M.Veronesi – Ed. Franco Angeli
Teaching methods
Theoretical lessons and laboratory applications
Assessment methods and criteria
Written test and practical laboratory test
