Linear Parameter-Varying Versus Linear Time-Invariant Reduced-Order Controller Design for Turboprop Aircraft Dynamics

Widowati Widowati (Mathematics Department, Diponegoro University Jalan Prof. H. Soedarto, S.H., Semarang, Jawa Tengah 50275, Indonesia)
Bambang Riyanto (Electrical Engineering Study Program, Institut Teknologi Bandung Jalan Ganesha No. 10 Bandung, Jawa Barat 40132, Indonesia)
Hari Muhammad (Aerospace Engineering Study Program, Institut Teknologi Bandung, Jalan Ganesha No. 10 Bandung, Jawa Barat 40132, Indonesia)

Journal of Engineering and Technological Sciences
Vol. 44 No. 2 (2012)

The  applicability  of  parameter-varying  reduced-order  controllers  to aircraft  models  is  proposed.  A  generalization  of  the  balanced  singular perturbation method of the linear time-invariant (LTI) system was used to reduce the order of  the  linear parameter-varying (LPV) system. Based on the reducedorder model, a  low-order  LPV  controller  was  designed  using  the H∞ synthesis technique.  The  performance  of  the  reduced-order  controller  was  examined  by applying  it  to  the  lateral-directional  control  of  a  20th-order  aircraft  model. Furthermore, the time responses of the closed-loop system with  several reducedorder LPV controllers and  a  reduced-order LTI controller  were  compared.  The simulation results  show that an  ,  8th -order LPV controller can maintain stability and  provide  the  same  level  of  closed-loop  system  performance  as  a  full-order LPV  controller.  This  was  not  the  case  with  the  reduced-order  LTI  controller, which  cannot  maintain  stability  and  performance  for  all  allowable  parameter trajectories.