Adaptive control of intake air conditioning systems for engine testing

The temperature and humidity control of an intake air conditioning (IAC) system for internal combustion engine testing is considered. A decentralized control structure with four PID controllers is proposed, where the PID parameters are chosen using either the Ziegler–Nichols method or a fuzzy gain scheduling. Experimental tests were conducted on a diesel engine test bench to obtain air conditions data to simulate a closed-loop system. A simulation model of the IAC system is used to evaluate the two PID parameter approaches, and the results show that a fuzzy gain scheduling approach achieves small improvements in terms of settling time and steady-state error.