Data-driven operational pressure estimation for hydraulic actuators fed by fixed displacement pump with variable speed

The paper provides the estimation method of the pressure level in the hydraulic drive with actuator fed by variable speed fixed displacement pump (VSFD). The experimental tests were conducted using a typical speed shape in working cycle of the exemplary machine as is the hydraulic indirect elevator. The different piston rod loads and speeds were applied to measure the wide range of pressure values. Obtained data allowed to determine the two-variable estimation functions describing the cylinder inlet pressure values. Pressure mapping quality factors, as the measures of estimation inaccuracy, were introduced. The pressure estimation methods provided satisfactory results in whole range of data. The developed methods allow to support for rapid estimation of operational pressures for hydraulic drives with VSFD pumps, thereby improving the reliability and safety of these systems. Obtained factors can be used in modelling the hydraulic systems and simulations. Further analysis can provide the information for the manufacturers to optimize the hydraulic element sizes.