Sliding Mode Control of Non-Interacting Two-Tank System Using Conditional Integrators

The paper describes the set point regulation of liquid level in a non-interacting two-tank system using a sustained sliding mode control (SMC) approach enhanced by integral action. The integrator is conventionally introduced to provide integral action to eliminate the transient performance degradation and is represented as a conditional integrator (CI). The goal of the process is to maintain the liquid level in the tank at the reference desired set point. A CI controller is used in the coupled tank system to regulate the inflow rate, ensuring the liquid level remains at the specified set point. It also retains the robustness to uncertain system parameters and disturbances characteristic of ideal SMC, but eliminates control chattering, which can lead to valve wear and tear. The simulation results demonstrate improved tracking performance despite the presence of disturbances and unmodeled dynamics.