Publication Date


Document Type


Committee Members

Ha-rok Bae (Committee Member), Hong Huang (Advisor), Junghsen Lieh (Advisor)

Degree Name

Master of Science in Engineering (MSEgr)


Electric wheelchairs have a considerable impact on improving the quality of life for the millions of disabled persons around the world. These modern pieces of technology offer freedom and mobility for disabled persons to interact with the world outside of their homes. The goal of this project is to assist in advancements of conventional electric wheelchairs. This includes replacing the heavy, bulky, and inefficient lead acid batteries and worm gear drive systems with lithium-ion batteries and wheel hub motors in order to decrease weight and size, and increase efficiency. This master thesis research is focused on designing, fabricating, and testing an eddy current brake dynamometer that can effectively determine the efficiency of the newly implemented wheel hub motor system at operational speeds. The importance of measuring the efficiency of the wheel hub motors used is to verify that they have a sufficient efficiency that would increase running time, extend traveling distances, and increase reliability. Because of the low speeds and high torque required, geared wheel hub motors were used instead of brushless permanent magnet hub motors. In this research, SolidWorks was used for modeling and to create an engineering drawing packet. The components of the dynamometer were machined and fabricated with a lathe and a milling machine. MATLAB was utilized for the calculations. With the help of the dynamometer platform, it was determined that the wheel hub motors have a higher efficiency but only at higher speeds. Although the geared hub motors used compromise some efficiency in order to produce greater torque at low speeds, they are light weight with compact size and have a much lower cost making them ease for maneuverability and economically feasible for next generation wheelchairs.

Page Count


Department or Program

Department of Mechanical and Materials Engineering

Year Degree Awarded