FOPDT modelling and controller comparative study for smart tube aqua filter (STAF) / Ahmad Aftas Azman ...[et al.]

Malaysian Meteorological Department statistics stated
that rainfall in this country is among the highest the world
with 2500mm a year. Therefore, the phenomenon of flooding
often occurs in Malaysia. Flooding will cause water to become
cloudy or turbid. This situation is getting worse as demand for
fresh water is higher than supply. Therefore, researchers have
designed several of water filter system to overcome these
issues. Not to mention, the usage of the chemical as a purifying
agent such as coagulant and flocculation process for turbidity
water purification. In this study, we used Aluminium Sulphate
Al
2
(SO4
)
3
as a coagulant agent, and Smart Tube Aqua Filter
(STAF) plan in flocculation process. This plant is modeled by
first order plus time delay (FOPDT) model, to explain the
behavior of processes. Model Predictive Controller (MPC) and
proportional integral derivative (PID) controller are applied to
control the process. Robustness and efficiencies of the
controller are analyzed and evaluated, and then a comparative
study is conducted for the best performance of transient
response. Finally, we found that MPC gives the best
performance of transient response in robustness test (step test
has faster settling time, of 5035.0 sec and overshoot percentage
of 0.0917%, Setpoint change test has performed better in five
(5) categories of the test), compared to PID controllers for
STAF simulation test.