Design and Modeling of Oceanographic Environment Adaptive Variable Pumps

Variable pumps are important hydraulic power units in deep-sea exploitation due to their good energy-saving and high precision capabilities. However, their application in such hostile environment suffers from the risk of control failure. Moreover, developed throughout trials and error in onshore simulation experiment, it is thus not just a time-consuming and expensive task but also required to implement an adaptive scheme capability to be used in deep-sea application. In this paper, a self-adaptive pressure sensing scheme and a novel close-loop control structure involved oceanographic environment adaptive variable pump (OEAVP) are proposed to autonomously adapt to the variable seawater conditions. Furthermore, based on environmental and fluid models, dynamic performances of the OEAVP model for pressure and flow-rate controls are analyzed. MATLAB/Simulink pack tool is used to perform the OEAVP system stability and comparative deep-sea water and shallow-water stability control are addressed. It reveals oceanographic environment influences on control performances of OEAVP from the direct effect of ambient pressure and the indirect effect of hydraulic fluid properties changes. Ultimately experimental tests including SPSS performances, control characteristics and dynamic responses of OEAVP's are performed in a simulation hull, which demonstrates consistent performances in oceanographic environment and confer to the proposed OSVP with high adaptive capability.