Power Shift Control of High-Power Tractor Based on Pattern Search

Highlights This article presents a multiobjective optimization function of power shift quality that uses the calculation formulas of sliding wear work, impact degree, and output torque derived from the analysis of split-phase dynamics. The calculation formulas of impact degree, sliding wear work, and output torque of each phase are derived, and a three-factor evaluation system of power shift quality is constructed. A pattern-search-based optimization method of power shift quality is proposed on the basis of the three-factor evaluation system of power shift quality. The power shift control based on pattern search algorithm optimizes the shift quality evaluation indexes and effectively improves the power shift quality of high-power tractors. Abstract . This study conducts a dynamic analysis of power shift by analyzing the key influencing factors of power shift quality. The power shift process is divided into low gear torque, sliding wear, and high gear torque phases. The calculation formulas of impact degree, sliding wear work, and output torque of each phase are derived, and a three-factor evaluation system of power shift quality is constructed. A pattern-search-based optimization method of power shift quality is proposed on the basis of the three-factor evaluation system of power shift quality. A multi-objective optimization function of shift quality is constructed using the linear change law expression of clutch oil pressure and the calculation of shift quality evaluation indexes of each phase. The multi-objective function is pretreated using a weighted coefficient method, and the change rule of clutch oil pressure is accurately optimized. Simulation and experimental results show that the power shift control based on pattern search algorithm optimizes the evaluation indexes of each shift quality and effectively improves the power shift quality of high-power tractors. Keywords: Pattern search, Power shift, Shift quality, Split-phase dynamics.