Empirical optimization of an angled spoke paddling wheel with self-rotating mechanism

The development of the maritime industry has led to a corresponding increase in maritime accidents. Maritime accidents are major events that are costly to recover and can cause casualties. Moreover, individuals who are brought to the scene for recovery or rescue are at risk. To tackle this issue, the wheel mechanism of a water rescue robot, i.e., the angled spoke paddling wheel (ASPW), has been studied. The purpose of this study is to optimize the paddle design parameters of the ASPW using the Taguchi method. Experiments are conducted by creating paddles with various combinations of design parameters using L-9(3(4)) orthogonal arrays. The objective function is determining the optimal combination of paddle design parameters that will produce the greatest thrust force at the same RPM. Sensitivity analysis of each design parameter is conducted by calculating the signal-to-noise ratio from the experimental results. The pitch angle is found to be the most sensitive parameter. An additional experiment is conducted based on the results of the sensitivity analysis. The results show that the optimal design parameters are a pitch angle of 0 degrees, rectangular end shape, X-axis curvature of 37.5 mm, and Y-axis curvature of 25 mm. The paddle with this combination of design parameters have a maximum thrust force of 64.74 gf at 120 RPM and exhibit up to an 18.27% improvement in performance compared with the initial paddle before optimization.