What is 4BL

In this chapter, the synthesis and analysis of four link bar (4BL) mechanisms problem, which is a well-known classical design problem, is discussed. However, limitations to the classical theory of this problem potentially limit its application to certain real-world problems by virtue of the small number of precision points and unspecified order. A prototype of the problem was designed and simulated for visualizing a four-bar link (4BL – simple movable closed chain linkage) mechanism engineering problem using MATLAB software. The aim is to facilitate the analysis, dynamic simulation of the four-bar mechanisms. First, a brief review of some of the current computer-aided learning software for four-bar mechanisms is presented. These software packages provide two-dimensional visualization and computational capabilities necessary to synthesize and analyze four-bar mechanisms. The chapter also reviews the kinematics of four-bar mechanisms as they pertain to their geometric modelling followed by the design approach of the graphical MATLAB simulation for 4BL mechanisms. A preliminary validation test using pre- and posttest questionnaires and focus group discussion with student participation in using the MATLAB simulation has facilitated in visualizing the engineering concepts of 4BL mechanism at UNITEN.