Asee peer logo

Hardware Experiments In Feedback Control Systems Using A Geared Dc Motor

Download Paper |


2004 Annual Conference


Salt Lake City, Utah

Publication Date

June 20, 2004

Start Date

June 20, 2004

End Date

June 23, 2004



Conference Session

Emerging Trends in Engineering Education

Page Count


Page Numbers

9.661.1 - 9.661.11



Permanent URL

Download Count


Request a correction

NOTE: The first page of text has been automatically extracted and included below in lieu of an abstract

Session 1793

Hardware Experiments in Feedback Control Systems Using a Geared Dc Motor Robert S. Weissbach Penn State Erie, The Behrend College


One of the difficulties in teaching control systems to engineering and technology students is to relate classroom theory and computer simulation to experimental results. Students tend to focus on analyzing feedback control systems without understanding where the transfer functions of real life systems come from. This effect is exacerbated by textbooks in control systems, where authors often assume that variables such as moment of inertia, damping coefficients and gear ratios are readily available when determining the transfer function of a system. The purpose of this paper is to present a series of experiments with a geared dc motor which is coupled to a rotary potentiometer. In the first experiment, the students look at the impulse response of the motor to determine the transfer function of the motor. Since an ideal impulse function cannot be provided, the students provide a short duration pulse to the motor to approximate an impulse. The results of experimentally determining the transfer function can then be used in a software package, such as Matlab, to compare simulation results to hardware results. In the second experiment, the students build a position control system for the geared dc motor and again compare results with simulation results. Non-linear effects such as saturation of operational amplifiers can be considered as part of both hardware and simulation. Students are able to gain a wealth of understanding from these labs, whereby the transfer functions in the textbook become more than just numbers and variables.


Senior students in Electrical Engineering Technology (EET) at Penn State Erie, The Behrend College are required to take a course in feedback control systems. This three credit course includes two hours of lecture, along with a two hour lab section, each week. The intended course outcomes are for the students to be able to:

• Utilize prior knowledge of Laplace transforms to solve s-domain transfer functions in the time domain • Determine open and closed loop transfer functions for a control system • Determine the time domain response characteristics of a control system (e.g., rise time, settling time, % overshoot, etc.) • Identify the different parts of a control system (e.g., actuator, sensor, controller, etc.) • Utilize Bode and Nyquist diagrams to determine the stability of a control system • Understand the difference between proportional (P), proportional + integral (PI) and proportional + integral + derivative (PID) control systems • Build both parts of and entire control systems in the laboratory “Proceedings of the 2004 American Society for Engineering Education Annual Conference & Exposition Copyright © 2004, American Society for Engineering Education”

Weissbach, R. (2004, June), Hardware Experiments In Feedback Control Systems Using A Geared Dc Motor Paper presented at 2004 Annual Conference, Salt Lake City, Utah. 10.18260/1-2--13820

ASEE holds the copyright on this document. It may be read by the public free of charge. Authors may archive their work on personal websites or in institutional repositories with the following citation: © 2004 American Society for Engineering Education. Other scholars may excerpt or quote from these materials with the same citation. When excerpting or quoting from Conference Proceedings, authors should, in addition to noting the ASEE copyright, list all the original authors and their institutions and name the host city of the conference. - Last updated April 1, 2015