Date of Award

5-2012

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Mechanical Engineering

Advisor

Wagner, John R

Committee Member

Dawson , Darren M

Committee Member

Schweisinger , Todd

Abstract

The improvement of consumer products and industrial processes, in terms of functionality and reliability, has recently focused on the integration of sensors and real time controllers with attached actuators into the given physical system. The likelihood of long-term market penetration of smart devices has placed an emphasis on preparing engineering graduates for technology leadership roles in the workforce. This thesis examines mechatronic systems in two manners. First, an intelligent automotive internal combustion engine cooling system is studied for ground vehicles using hydraulic actuators which offer the opportunity for greater versatility and performance. Second, improvements to a technical elective mechatronics course at Clemson University in the Department of Mechanical Engineering have been completed to offer a better educational experience for both undergraduate and graduate students.
Traditional and modern internal combustion engine cooling systems typically use a mechanical wax based thermostat along with a number of mechanical and/or electric actuators to remove the excessive heat of combustion from the engine block. The cooling system's main objective is to maintain the engine temperature within a prescribed range which optimizes engine performance and promotes mechanical longevity. However, the cooling system adds to parasitic engine losses and vehicle weight, so a mechatronic based smart thermal management system has been designed to explore the higher power density and controllability of hydraulic actuators. In this research project, the experimental data has been initially gathered using a 4.6L gasoline engine with a mechanical wax based thermostat valve, engine driven coolant pump, and a hydraulic motor driven radiator fan with classical feedback control. A series of mathematical models for the hydraulic, electric, and thermal automotive subsystems have been developed to estimate the engine, coolant, and radiator temperatures as well as the overall system performance for various operating conditions.
The experimental test platform features a medium duty eight cylinder internal combustion engine, stand-alone radiator, engine dynamometer, smart cooling system components, high speed data acquisition system, and real-time control algorithm with associated sensors. Specifically, J-type and K-type thermocouples measure the engine block, coolant, and radiator core temperatures at various locations. A multiplexer switches these input signals at predetermined intervals to accommodate the large number of temperature probes. Further, optical sensors measure the engine and radiator fan speeds, and pressure sensors record the hydraulic line pressures. A hydraulic direction control valve was used to adjust the speed of the radiator fan. The experimentally recorded engine data was compared with the numerical simulation results to estimate the engine's thermal behavior for warm up and idle conditions. The findings demonstrated that the proposed experimental model and mathematical models successfully controlled the engine temperature within ±1.5°K . In the future, the mathematical models can be used for linear quadratic regulator and Lyapunov-based nonlinear controllers after further refinement and the addition of state variables for the engine thermal management system.
To implement such a mechatronic-based cooling system, engineers must have a fundamental understanding of system dynamics, control theory, instrumentation, and system integration concepts. Given the growing industrial demand for graduates with diverse engineering knowledge, a mechatronic systems course has been designed in the Department of Mechanical Engineering at Clemson University. This mechatronics course, ME 417/617, has been designed to introduce both engineering and personal skills. The students, who would successfully complete the course, will be able to join global work teams designing smart products. The course uses various teaching paradigms such as classroom activities, laboratory experiments, team based design projects, and plant tours to introduce the concepts and offer hands-on experience. As part of a continuous improvement process, the course has been evaluated using assessment methods such as pre- and post-tests, qualitative measures, and advisory panel observations.
Over a four course offering period (2008-2011), the pre- and post-tests reflect improvements in the students' personal growth (7.0%), team building (12.8%), mechanics/engineering (25.4%), and human factor (17%) skills. The qualitative assessment was completed using student feedback regarding the course content. Most of the students reported that they liked the course and its 'hands-on' experimental approach. An advisory panel, consisting of industry experts, course instructors, and faculty analyzed the progress of students and evaluated the course materials. The advisory panel's recommendations established the direction for continuous improvements to successfully teach the concepts of mechatronics and better meet the student needs. Going forwards, the mechatronic systems course will serve an important role in preparing graduates for future endeavors.

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Engineering Commons

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