Performance optimization of a rotary mower using Taguchi method

Optimum energy consumption and prevention of energy losses are important issues in various fields including agricultural engineering. Mower is one of the agricultural machineries that can waste too much energy if does not function properly. In this study, the performance of a single disc rotary mower was studied and optimized by measurement of cutting quality of the stem cross section (cutting quality) as a criterion. Taguchi L9 orthogonal arrays table was used to find the optimum combination of parameters to reach the best cutting quality. The selected factors are: mower forward velocity, disc rotational speed, number of disc blades and shape of the blade, each one at 3 different levels. To measure the quality of the cut hay, ENVI image processing software was used. This software has been developed for texture qualification of image processing studies. The texture of the images captured from the cross section of cut stems by the mower is analyzed according to the reflected wavelength from the surface. ENVI software assigns a number to the cutting quality of each stem, which is called eigenvalue. The results then were imported to the orthogonal arrays table of the Taguchi method. Minitab software was used to calculate the optimal level of the studied variables. Analysis of the results show that 886 rpm of the disc rotational speed, 1m s of the forward speed, four symmetrical triangular serrated blades on the mower disc are the optimal values of the factors and offer the highest cutting quality. The optimum value predicted by the Taguchi method was approved by an experimental method.