Nicholas Stickle M.S. final exam and defense
Tuesday, June 26, 2012, 10:30 AM
Mechanical Engineering Conference Room

Nicholas Stickle will present his M.S. final exam and defense at 10:30 a.m., Tuesday, June 26, in the Mechanical Engineering Conference Room.

Title: "Modeling and Microcomputer Based Control of a DC Motor for an Instructional Laboratory"

Advisor: David Alciatore, Ph.D. 

Committee: Peter Young, Ph.D., Wade Troxell, Ph.D.

Abstract

The intent of this technical paper is to model and design a microcomputer based controller for a DC motor with off the shelf, inexpensive components, with the intent to design an instructional laboratory. This laboratory experience extends the microcontroller material currently taught in the mechatronics course (MECH307) providing an introduction to control theory. Likewise, this experience could be used in the controls course (MECH417) to help the students relate control theory to the practical tools learned in the mechatronics course. The secondary purpose of this paper is to create a case study that could be used in the next edition of the textbook “Introduction to Mechatronics and Measurement Systems” by David G. Alciatore and Michael B. Histand to allow other universities using the book to offer a similar experience to their students. Using the equations of motion for a DC motor, the transfer function of the motor can be derived allowing a motor model to be built in Simulink. Using built in Simulink software, a controller is built for a linearized motor model. A gear reduced motor contains much nonlinearity including friction and saturation limits of the system. These linear and nonlinear models can be compared, and an understanding of the effects of linearizing a system can be presented. Experimental methods were performed to determine motor parameters, comparing them to the theoretical values provided by the manufacturer. This allowed for an end assessment that affects the overall system and controller. It was found that the difference in parameters from the actual and theoretical was significant. When the closed loop system is linearized and a controller is built around the linearized system, saturations were prevalent, which caused components to run on their limits, decreasing their effectiveness and lifespan. Therefore, the controller variables were adjusted to reduce the effect of saturation. Using the experimental parameters and controller model, PICBasic code for a PIC microcontroller PID control loop was generated and a circuit was designed and built. Using sections of this code and the equations of motion for the motor, a laboratory exercise was created to aid in increasing the microcontroller material currently found in the mechatronics course.

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Event Contact: Karen Mueller can be reached at (970) 491-3872

Sponsored by the Department of Mechanical Engineering.