Digital Control Systems
Spring 2015
Catalog Data: 

ECE 442 -- Digital Control Systems (3 units)

Description: Modeling, analysis and design of digital control systems; A/D and D/A conversions; Z-transforms; time and frequency domain representations; stability; and microprocessor-based designs

Grading: Regular grades are awarded for this course: A B C D E

May be convened with ECE 542

ECE 320A

Aström, Karl and Richard M. Murray. Feedback Systems: An Introduction for Scientist and Engineers. Princeton University Press. Online. <>
DiStefano III, J.J., A.R. Stubberud, and I.J. Williams. Feedback and Control Systems: Continuous (Analog) and Discrete (Digital). 2nd Ed. McGraw-Hill. 1990.

Course Learning Outcomes: 

By the end of this course, the student will be able to:

  1. Convert a continuous-time system into a discrete-time system (frequency and time domain techniques).
  2. Compute the z-transform of elementary signals and difference equations.
  3. Determine the poles of a second-order system based on the system's transient response (both continuous time and discrete time systems).
  4. Determine the stability of a closed-loop system (both continuous time and discrete time systems).
  5. Sketch the root locus associated with a system's transfer function (both G[s] and G[z]).
  6. Translate design specifications into allowable dominant pole locations in both the s-plane and the z-plane.
  7. Design controllers using root locus techniques (both continuous time and discrete time).
  8. Incorporate time delay introduced by a zero-order hold and know how to accommodate this delay during a digital controller design.
  9. Obtain discrete equivalents of analog transfer functions.
  10. Apply full-state feedback to achieve acceptable closed-loop behavior for discrete-time systems.
  11. Design an estimator and use it to control a discrete-time system.
  12. Design a digital PID controller based on an existing analog PID controller.
  13. Transform between difference equations, block diagrams, and transfer functions associated with discrete systems.
  14. Compute closed-form expressions for output waveforms from discrete-time systems with inputs.
  15. Determine the steady-state error in continuous time and discrete time systems.
  16. Transform discrete-time systems between transfer function and state-space representations.
Course Topics: 
  • Linear, continuous and discrete, dynamic-system analysis
  • Sampled-data systems
  • Discrete equivalents of analog transfer functions
  • Controller design using transform techniques
  • Controller design using state-space techniques
Class/Laboratory Schedule: 

Two, 75-minute lectures per week

Relationship to Student Outcomes: 

ECE 442 contributes directly to the following specific Electrical and Computer Engineering Student Outcomes of the ECE department:

  • an ability to apply knowledge of mathematics, science and engineering (High)
  • an ability to design and conduct experiments, as well as to analyze and interpret data (Low)
  • an ability to design a system, component, or process to meet desired needs within realistic constraints such as economic, environmental, social, political, ethical, health and safety, manufacturability and sustainability (Low)
  • an ability to identify, formulate and solve engineering problems (Medium)
  • an ability to use the techniques, skills, and modern engineering tools necessary for engineering practice (High)
Prepared by: 
Dr. Hal Tharp
Prepared Date: 

University of Arizona College of Engineering