Abstract: When a high-power bulldozer works with the heavy load for a long time, the efficiency of hydraulic mechanical transmission decreases obviously. To solve this problem, the dynamic simulation model of bulldozer power transmission is constructed based on modularization theory. And a dynamic match strategy of guaranteeing the high transmission efficiency is designed. Moreover, a load control model and a throttle opening control model are constructed. And then the optimizing design platform is established to confirm and optimize the PID parameters of load control and throttle opening control model adopting Isight and Matlab software. Eventually, hardware-in-the-loop test is designed and accomplished. The results show that the proposed dynamic matching strategy increases the transmission efficiency of bulldozer obviously under continuous operation conditions, and insufficient power during long operation process is effectively controlled.

Key words: efficiency control, hydrodynamic-mechanical transmission, dynamic matching, hardware-in-the-loop test, bulldozer