Abstract: The electro-hydraulic flow matching control system with the electro-proportional valve and electro-proportional pump works in a synchronous control mode of the valve and pump. It eliminates the hysteresis between the pump and valve in the traditional load-sensing systems nearly. Closed-loop feedback control of pressure and preset pressure margin between pump and maximum load pressure are not needed. It reflects the combination of flexibility and efficiency of hydraulic systems, improving energy efficiency and control performance. The experimental prototype of 2-ton excavator with the electro-hydraulic flow control system is taken as the investigation subject. Energy consumption and dynamic characteristic are comparatively analyzed between the traditional load sensing hydraulic system and the electro-hydraulic flow matching hydraulic system. The controller with flow share capabilities is designed for electro-hydraulic flow matching control. Compared with the traditional load-sensing system, the electro-hydraulic flow matching hydraulic system has the same as with post compensation with anti saturation. The pressure margin is reduced by more than 0.6-0.7 MPa, and the energy consumption is decreased by 8%-10%. It can not only improve the dynamic characteristic and energy efficient, but also the system stability.

Key words: Dynamic characteristic, Electro-hydraulic flow matching control, Energy-saving, Load-sensing, Mobile machine