Study on displacement control strategy of two ranges hydro-mechanical transmission

In order to study the dynamic characteristics of the hydro-mechanical transmission (HMT) system, a simulation model of a two ranges HMT system is established in an object-oriented environment. In virtue of the powerful software tool, the dynamic of the non-linear variable displacement hydrostatic unit is simulated. Based on the analysis of the dynamics characteristics of the hydrostatic transmission mechanism, a displacement control strategy was designed to reduce the non-linear effect of the variable displacement hydrostatic unit and to decrease the speed rising during the range changeover. The simulation results demonstrate the control strategy can decrease the output speed oscillation and improve the shift quality of the HMT system.