In proc. ASME Intl Mech. Engng Cong. and Expo. (IMECE) Dynamic Systems and Control Div., DSC series, New Orleans, November 2002.
Experimentally identifying the transfer function of an electromechanical system
Richard A. Layton and Clifford Grigg

An experiment is developed in which the instructor demonstrates the acquisition of frequency response data for an electromechanical system (an X-Y recorder). Students are given copies of the acquired data, from which they create an amplitude response plot and develop a transfer function for the system. Using a simple optimization routine, students tweak the model until the predicted amplitude response most closely matches the experimental data. The model is refined further by adding a zero to the transfer function. Students compare the predictions of their models to the experimental data and answer related questions on a lab worksheet, all within one three-hour lab period. In this paper, the apparatus, demonstration, data reduction, system identification, and results are described. A videotaped demonstration of the experiment, sample data, and the lab handout and worksheet are available online at In future work, the experiment will be modified to measure phase response.

©2002 American Society of Mechanical Engineers.

Return to list of publications

Richard A. Layton
Last modified: 26 Nov 02