Document Type



Master of Science


Mechanical Engineering

First Adviser

Meng-Sang Chew


Dimensional synthesis of the four-bar mechanism could not be determined precisely due to many constraints such as manufacturing tolerance, joint clearance, thermal deformation, the deflection and so on. All of these constraints are included in the uncertainty of the dimensions of the four-bar mechanism. In this research, this uncertainty will be modeled based on the fuzziness one of the precision points of Freudenstein's equation that builds intervals of link’s dimensions with membership functions. They represents the probability of the dimensions value depending on the uncertainty of the positions of the precision point itself rather than uncertainty of the external information about the mechanism dimensions. The results of the fuzzy synthesis will be defuzzified using the centroid defuzzification method to get the dimensions of the mechanism. Then, the resultant function from the fuzzy synthesis is comparing with the crisp one to study the range and limits of the fuzziness operation in the generated function.