An indirect flow measurement method for bi-tandem axial piston pump based on leakage flow estimation.

• A leakage flow estimation model based on swashplate position and operating conditions is established by a displacement transducer at actuator piston. • An indirect flow measurement for a bi-tandem axial piston pump is proposed by considering leakage, flow ripple, and compressibility. • The method enables output flow monitoring and feedback without the need for flowmeters in pump-controlled hydraulic systems, avoiding additional energy consumption and cost increase. In pump-controlled hydraulic systems, configuring a flowmeter at a variable piston pump to monitor output flow causes additional losses. A method for indirect flow measurement of the bi-tandem axial piston pump based on flow leakage estimation is proposed to address this problem. The method first installs a displacement transducer at the actuator piston to collect data on the actuator piston position, outlet pressure, and shaft speed, then estimates leakage of key kinematic pairs, and finally considers flow ripple and fluid compressibility to form an indirect measurement for output flow of the pump. The indirect measurement accuracy under various typical operating conditions is analyzed. The results demonstrate that the mean absolute percentage error of the proposed indirect flow measurement method is less than 2.10%, and the method is effective with high measurement accuracy. The indirect measurement method avoids extra costs and energy consumption associated with configuring flowmeters in engineering hydraulic systems. [ABSTRACT FROM AUTHOR]