The process control system attempts to emulate complex systems such as those
found in chemical process control industries. The experiment consists of
four liquid tanks, four liquid-level measuring devices, two temperature
measuring devices, two mixers, and two heaters. The liquid-level in each
tank is measured by a potentiometer attached to a Styrofoam float. Temperature
measurements are made via temperature transducers that are mounted in the
reaction chamber and in the hot tank. The reaction chamber and hot tank
also each contain a heater and stirrer; the stirrers aid in liquid-level
sensing and ensure a uniform temperature throughout the tank. The AC pump
is used to remove liquid from the reaction chamber, while the two DC pumps
pump liquid from the hot and cold tanks to the reaction chamber. Currently
the AC pump is configured to pump liquid from the reaction chamber to the
hot tank; however, the AC pump could also be used to pump liquid from the
reaction chamber to the storage tank. The AC pump, heaters, and stirrers
may be turned on or off independently; these devices compose the plant's
five discrete inputs. The flow rate of the two DC pumps may be varied independently
by varying their supply voltage (this is done using PWM and is transparent
to the user); the DC pumps compose the plant's two continuous inputs. Two
of the difficulties associated with the process control system include:
Publication:
Zumberge J., Passino, K.M., "A Case Study in Intelligent vs. Conventional Control for a Process Control Experiment," Journal of Control Engineering Practice, Vol. 6, No. 9, pp. 1055-1075, 1998.