A Review of Flow Saturation Resistant Techniques in Multi-actuators Load Sensing Hydraulic System

The multi-actuator load-sensitive (LS) system has gained widespread usage in engineering machinery applications due to its energy efficiency, exceptional composite action performance, and precise tuning capabilities. However, when the demand for load flow exceeds the supply of hydraulic pumps, flow saturation conditions may arise in hydraulic pumps, thereby impacting the coordination of multi-actuator actions and diminishing the load sensitivity characteristics of the system. To address this issue, scholars have proposed anti-flow saturation technology. Currently effective solutions include reducing the set pressure of pressure compensator valve springs and decreasing the opening degree of each main valve. Anti-flow saturation technologies for multi-actuator load-sensitive systems can be classified into three types based on the location of pressure compensators in different circuits: pre-valve; post-valve and outlet pressure compensation anti-saturation, as well as a novel type known as independent metering (IM) technology. This article provides an overview of significant accomplishments in these three types of anti-saturation technologies before introducing IM technology and discussing research focal points for various types of load-sensitive systems as well as how anti-saturation technologies impact their energy efficiency. Finally, future directions for development in flow saturation resistant technologies within muti-actuators load sensing systems are explored.