Research on flow measurement and control integrated strategy based on a flow sensor with active regulation

Accurate flow measurement is crucial for the efficient operation and precise control of hydraulic systems. However, current flow measurement and control technologies exhibit certain limitations. Existing flow sensors suffer from increased pressure drop as flow rise, resulting in diminished measurement accuracy and higher energy consumption. Soft measurement methods for flow rely heavily on extensive experimental data sets, which may not always be available or practical. Pressure compensation valves also present challenges, including inadequate control accuracy, reduced flow capacity, and elevated pressure drop. To address these issues, this paper proposes an innovative method for a flow sensor with active regulation capabilities, which directly converts spool displacement into flow information. Additionally, an electromagnetic force active control unit is incorporated to compensate for measurement errors caused by factors such as spring force and flow force. The active control unit can also adjust flow gain to expand the measurement range or enhance measurement resolution, thereby accommodating both high-flow and low-flow conditions. Furthermore, the sensor can be easily installed on the valve to facilitate high-precision closed-loop flow control without the need for pressure compensation valves. The effectiveness of the proposed configuration and method has been validated verified through multidisciplinary co-simulation and testing. Results indicate that the flow measurement error is approximately 0.66 % with active regulation, and variable flow gain functionality can be achieved. The flow control accuracy is about 1 %, and the system demonstrates strong anti-load disturbance.