A simulation of digital load sensing system for water hydraulics

Recently, the application of water hydraulics has been increasing in many fields as shown in [1], [2], [3]. However, water hydraulic systems using servo/proportional valves have inherent disadvantages such as low energy efficiency and high installation cost, which prevent water hydraulics from applying widely. Water hydraulic variable displacement pump does not exist in the market and therefore supply pressure of water hydraulic systems cannot be adjusted by using load sensing, this is a very important reason for low energy efficiency of water hydraulic systems. This study aims to introduce a novel digital load sensing (DLS) that uses a set of On/Off valves assembled to a servo system for reducing much surplus pressure thanks to the supply pressure track a required pressure. By using of fast On/Off valves, the supply pressure can be tracked the reference pressure quickly, this ensures that the energy consumption of the system is reduced much while the control performance of the load still remains in high quality. The simulation results showed that by applying the DLS system, the energy efficiency can increase nearly double in comparison with a system that does not use DLS.