Kinematic Synthesis and Analysis of a Watt II Six-Bar Linkage for the Design and Validation of an Open Loop Solar Tracking Mechanism

Abstract

Tracking mechanisms were found to improve the performance of solar renewable energy systems that contribute to energy sustainability and security. However, the commonly used closed-loop solar trackers require sophisticated equipment that leads to high upfront costs and energy consumption. The literature suggests that simpler open-loop trackers can be sought as a feasible alternative for small-scale applications. In this study, an open-loop solar tracking mechanism was designed through the kinematic synthesis of a Watt II six-bar linkage using Freudenstein’s method and analytical position method. The desired motion of the mechanism was obtained using the solar apparent motion trajectory model. A finite number of precision points were selected using Chebyshev’s spacing to simplify the synthesis while minimizing the error. The design was validated through kinematic analysis using loop closure equations and complex number analysis. The position, velocity, and acceleration behaviors obtained from the numerical method done in MATLAB was compared to that of the graphical method done in MechAnalyzer. The synthesis results hint the special considerations needed in the physical implementation of the design, while the validation results show a general agreement between the results of the numerical and graphical kinematic analyses, implying the effectiveness of the presented methodology.