Parameter optimization of vibration subsoiler test bed for reducing resistance and vibration

Abstract: The oscillatory tillage was proved to be more efficient than rigid tillage. Oscillation could reduce the drag resistance during tillage. But the oscillation had a bed effect on the tractor. Oscillation damaged the tractor and was harmful to tractor driver. The goals were to reduce the drag residence and the effect on the tractor. These two goals couldn't be optimum at the same time. But it had a relative optimum combination. The Six-component test system on the experiment trolley could measure the forces in the directions of heading(X), vertical (Z) and crosswise (Y). Define the mean value of X-direction force as the mean of resisting force F1, the interquartile range of Z-direction force as the range of vibratory force F2. The working parameter of oscillatory tillage that to be considered were amplitude e(a), frequency (f) and velocity (v) in the experiments. Using quadratic general revolving combination design with 3 factors, the regression models between F1, F2 and amplitude, frequency, velocity were founded. There were two three-factor quadratic regression models. The influence order could be found in the perturbation graph for non-interaction parameters, but couldn't be found for interactive parameters, because the trend of perturbation curve changed when the interactive parameters was changed. The path analysis method could find both direct and indirect influences of interactive parameters. Using the interaction analysis method in the Design-Expert and the path analysis method in the SPSS, the influence order of three factors was determined, a>f>v, to both F1 and F2. There were no optimal solutions for this multi-objective optimization problem, but there were relative optimal solutions for it through the method of desirability function method. The higher the desirability value, the better the solution. From the 3D response surface of desirability at different velocities, in order to achieve high speed work, the relative optimal solution of both the goal of low resisting force and that of low vibratory force was small amplitude, high frequency and high speed, the values were 21 mm, 4.2 Hz and 3.4 km/h. The inaccuracy between the predicted value of regression model and the result of verification test was acceptable. The maximums of resisting forces during oscillation and non-oscillatory tillage were similar, but the force reductions of minimum and mean values were 46.2% and 16.6%. Comparing with the single objective optimal solution of F1, the multi-objective optimization reduced the vibratory force. It achieves that resisting force decreases and at the same time the vibration on vertical direction decreases during oscillatory tillage.