In this paper, an integrated FLC is proposed to address important
areas of concern in complex split-range control of multiple
nonlinear actuators in a hybrid configuration. First, integrated PID
control is applied to a simulation case comprising a continuous
input request that varies across the boundaries of the individual
actuators. The results suggest that PID-based control does not
provide an optimal solution for the investigated split-range control
problem.
The performance of the integrated FLC is evaluated by means
of simulation cases comprising different complex input requests.
Results show that the proposed controller effectively coordinates
and switches actuators for complex operating scenarios, signifi-
cantly reducing nonlinear transitions in the total mass flow rate.
From the simulation studies, it became apparent that signal prediction
is an important task in split-range control. The proposed NN
signal predictors successfully envisage problematic input requests
to improve control precision. The problems of poor LV resolution
and stiction are addressed by implementing appropriate fuzzy
rules. The performance achieved by the FLC, with expert knowledge
as basis for system parameter definition, confirms that FL provides
a naturalframework for complex split-range control of hybrid actuators.
This warrants continued research in autonomous global FLC
parameter optimization.
While the study showed control of a specific hybrid actuator
(two-valves-in-parallel), the proposed control scheme can be generalized
to address split-range control issues for different nonlinear
hybrid configurations. With little modification, the summarized
implementation procedure serves to provide a systematic modeling
approach for this task. However,the complexity ofthe proposed
split-range control scheme warrants further research to simplify
parameterization and implementation.