Bi-objective pareto optimization of centric crank-rocker mechanisms

Abstract

This paper revisits a classical problem in linkage mechanism design, specifically the design of centric crank-rocker mechanisms for a specified rocker stroke with unit time ratio. Beyond the traditional objective of minimizing the transmission angle’s deviation from 90 degrees, this paper uses another objective: maximizing the shortest-to-longest link-length ratio in the linkage. The former objective ensures motion transmission quality in the mechanism, while the latter aims to make the mechanism less sensitive to variations in link lengths. It is shown that these two objectives are inherently conflicting, necessitating a trade-off solution. To address this, a Pareto front is developed by analyzing the governing design equations. The front is further normalized by relating each objective to its limit value. A design example using the normalized front is provided that showcases different optimization options. The TOPSIS method is used to illustrate the selection of a preferred design alternative.

Keywords:

• Optimum design
• crank-rocker
• transmission angle
• Pareto analysis
• normalized front

REVIEWING EDITOR:

• Pham D. T., University of Birmingham, United Kingdom

SUBJECTS:

• Design
• Mechanical Engineering Design
• Mechanics
• Mechanical Engineering

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article.

Additional information

Notes on contributors

Abdullah F. Al-Dwairi

Abdullah F. Al-Dwairi is an associate professor of mechanical engineering. He received his PhD from Saint Petersburg State University of Technology and Design. His research interests include mechanical system dynamics and design, manufacturing technologies, and product design and development.