The primary focus of this study is to investigate the control strategies of a hybrid system used in hydraulic excavators. First, the structure and evaluation target of hybrid hydraulic excavators are analyzed. Then th...The primary focus of this study is to investigate the control strategies of a hybrid system used in hydraulic excavators. First, the structure and evaluation target of hybrid hydraulic excavators are analyzed. Then the dynamic system model including batteries, motor and engine is built as the simulation environment to obtain control results. A so-called multi-work-point dynamic control strategy, which has both closed-loop speed PI (proportion integral) control and direct torque control, is proposed and studied in the simulation model. Simulation results indicate that the hybrid system with this strategy can meet the power demand and achieve better system stability and higher fuel efficiency.展开更多
Based on the working principle of vibratory excavation of hydraulic excavator,the expression of digging resistance changed with time under sine wave inspiritment was deduced;a comparison analysis was given after calcu...Based on the working principle of vibratory excavation of hydraulic excavator,the expression of digging resistance changed with time under sine wave inspiritment was deduced;a comparison analysis was given after calculating the forces status of rock and soil under static load and vibratory load respectively by using MATLAB;and then RFPA-2D(rock failure process analysis code)was used to make comparison of simulation experiment on rock and soil failure process under static load and vibratory load.The results demonstrate that,compared with the normal excavation under the same situation,the digging resistance and the energy consumption can be reduced by respectively 30%and 60%at maximum,and that the working efficiency can be increased by 45%at maximum owing to vibratory excavation.展开更多
基金Project (No. 2006C11148) supported by the ScienceTechnology Project of Zhejiang Province, China
文摘The primary focus of this study is to investigate the control strategies of a hybrid system used in hydraulic excavators. First, the structure and evaluation target of hybrid hydraulic excavators are analyzed. Then the dynamic system model including batteries, motor and engine is built as the simulation environment to obtain control results. A so-called multi-work-point dynamic control strategy, which has both closed-loop speed PI (proportion integral) control and direct torque control, is proposed and studied in the simulation model. Simulation results indicate that the hybrid system with this strategy can meet the power demand and achieve better system stability and higher fuel efficiency.
基金Project(2003AA430200)supported by the National High-Tech Research and Development Program of China
文摘Based on the working principle of vibratory excavation of hydraulic excavator,the expression of digging resistance changed with time under sine wave inspiritment was deduced;a comparison analysis was given after calculating the forces status of rock and soil under static load and vibratory load respectively by using MATLAB;and then RFPA-2D(rock failure process analysis code)was used to make comparison of simulation experiment on rock and soil failure process under static load and vibratory load.The results demonstrate that,compared with the normal excavation under the same situation,the digging resistance and the energy consumption can be reduced by respectively 30%and 60%at maximum,and that the working efficiency can be increased by 45%at maximum owing to vibratory excavation.
