A limited number of actuators with limited strain capabilities are located within the structure in order to achieve a target deflected shape starting from an initially symmetric profile. Two objective functions are used to achieve this: a geometric objective for which the target displacement is fixed and a shape objective for which the target displacement is dependent on the surface shape of the targeted aerofoil. The proposed shape objective function is able to offer improvements over the geometric objective by removing some of the constraints applied to the targeted structure joint locations.
Four methods for selecting the location of a set of actuators are compared, namely
exhaustive search, a genetic algorithm, stepwise forward selection (SFS) and incremental
forward selection (IFS). Both SFS and IFS are variations of regression methods for subset
selection; in each case an approach has been created to allow the imposing of upper and lower
bounds on the search space. It is shown that the genetic algorithm is well suited to addressing
the problem of optimally locating a set of actuators; however, regression methods, particularly
IFS, can provide a rapid tool suitable for addressing large selection problems.