Abstract:The existing darkroom mode of the automatic tray winch has encountered problems such as a decline in qualification rate and working stability, as well as damage to seedlings and rice trays during transportation. To address these issues, an improved hook rod lifting device with axial auxiliary push function for rice trays was designed. A simulation single factor test platform was constructed to determine the main parameters and their value range that affected its performance. The structure parameters of key components were determined, and a multi-case target evaluation result function was established by using Matlab interpolation method for standardization of evaluation index. The quadratic regression orthogonal rotating center combination test method was adopted, with tray spacing, transverse conveying speed, and lifting angle as test factors, while tray lifting qualification rate, leaf damage rate, hard disk damage rate, and number of injured seedlings served as performance evaluation indexes. Parameter combination optimization tests were conducted on the Rocky-DEM simulation test platform that had been constructed. Design-Expert 11 software was used for multi-objective parameter combination optimization. Field verification tests under conditions of 190mm tray spacing, 0.20m/s transverse conveying speed, and 72° lifting angle achieved a tray lifting qualification rate of 97.5%, leaf damage rate of 0.52%, hard disk damage rate of 0.45%, number of injured seedlings at 9 units, with an error of less than 1% compared with the theoretically optimized value. In comparison with the non-optimized lifting and stacking device, the pass rate for tray lifting was increased by 5.6 percentage points, leaf damage rate was decreased by 3.5 percentage points, reducing seedling damage, and hard tray damage rate was decreased by 3.8 percentage points.
