Advanced regulatory control strategies for MISO hammerstein systems

Advanced Regulatory Control (ARC) strategies, such as split-range and mid-ranging control, extend the capabilities of classical PID controllers to Multi-Input Single-Output (MISO) processes by coordinating manipulated variables. However, when input nonlinearities are present, as in Hammerstein systems, variations in the effective process gain lead to operating-point-dependent closed-loop behaviour. Although model predictive control approaches for Hammerstein systems are well documented, the systematic integration of input nonlinearity compensation into classical ARC architectures remains largely unexplored. This paper presents a framework for incorporating static input nonlinearity compensation into traditional ARC strategies for Hammerstein MISO processes. By including the inverse of each input nonlinearity within the control structure, the effective plant seen by the primary controllers is linearised, allowing the direct use of well-established PID-based design and tuning methods. The framework is developed for split-range, mid-ranging, split-parallel, and PI-SITO control. Simulation results demonstrate consistent closed-loop performance across the operating range with minimal additional complexity.