A hybrid control framework is proposed as an alternative
for long
time delays in chemical processes. The hybrid approach mixes the numerical
methods in an internal mode control (IMC) structure, which uses the
particle swarm optimization (PSO) algorithm to improve the adjustment
of the controller parameters. Simulation tests are carried out on
linear systems of high order and inverse response, both with dominant
delay, and tests on a nonlinear process (chemical reactor). The performance
of the proposed controller is stable and satisfactory despite nonlinearities
in various operating conditions, set-point changes, process disturbances,
and modeling errors. In addition, experimental tests were performed
on a setup composed of two heaters and two temperature sensors mounted
on an Arduino microcontroller-based board called the Temperature Control
Laboratory (TCLab), with an additional software delay introduced.
The merits and drawbacks of each scheme are analyzed using radar charts,
comparing the control methods with different performance measures
for set-point and disturbance changes. Furthermore, the new controller
uses PSO to improve the tuning parameters.