Investigation of a Fuel Oil Viscosity and Temperature Control System Based on State Observation

To address the contradiction between simultaneous fixed-value control of heavy oil temperature and viscosity in current fuel viscosity and temperature control systems, this study analyzes the operating process and principle of heavy oil heating used in ocean vessels, and derives a differential equation for a fuel oil viscosity and temperature control system based on state observation. Using inlet and outlet temperatures as the state variables and heavy oil viscosity as the output variable, the system can be treated as a kind of affine nonlinear system, with coordinate transformation function vectors determined so as to derive the sliding mode variable structure form of the state observer. Finally, some programs were compiled for calculation and simulation using MATLAB. The results showed that, by using a sliding mode variable structure control, state variables could be tracked well during the control of output variables. This confirmed the superiority of output feedback control based on a model of the state observer.