Advanced PID architectures for tracking changing active constraints
For control engineers, this work provides a simpler, robust alternative to MPC for constraint tracking, though the approach is not entirely new.
The paper demonstrates that advanced PID architectures can effectively handle processes with changing and conflicting constraints, challenging the academic belief that model-based solutions like MPC are necessary. Two case studies (gas-liquid separation and barn air quality control) show successful application.
Advanced regulatory control (ARC), also known as advanced PID architectures, is a simple and robust way of controlling processes with changing and possibly conflicting constraints, where it previously was believed - at least in academia - that model-based solutions, such as MPC, were the only effective solution. To illustrate this, ARC is applied in two case studies. The first is a gas-liquid separation process, in which selectors and split-parallel control are combined to achieve bidirectional inventory control in which the throughput manipulator moves automatically to the most optimal position. The second case study is on keeping acceptable air quality (CO2-level) and temperature in a room (in this case, a barn for cows). The CO2 and temperature constraints can be conflicting, leading to a hierarchical switching network of PID controllers. Note: this is an extended version (with simulations) of paper at IFAC World Congress, August 2026, Korea.