Parameters optimization and control strategy of power train systems in hybrid hydraulic excavators

This paper studies on parameters matching and control strategy of power train systems for hybrid hydraulic excavators (HHEs). Load profiles of a 20-t excavator are measured and analyzed. Based on load profiles, considering working conditions, actual load and energy saving, a method which combines analysis method with model-based method together is proposed so as to give full play to the energy conservation and driving characteristics of hybrid power train system (HPTS) in HHE. Mechanical models and efficiency models of HPTS are built. Dynamic programming (DP) algorithm is used to control the HPTS in HHE under different system parameters. Genetic algorithm (GA) is employed to acquire HPTS parameters for optimal energy consumption. The simulation results show that the efficiency of the HHE is improved by 8.80% compared with that of traditional excavator. Experiments are carried out and a rule-based control method is used to validate the effectiveness of the designed parameters.