Combat planes are designed in a structured relaxed static stability to meet maneuver requirements. These planes are unstable in the longitudinal axis and require continuous active control systems with elevator control. Therefore, failures in the elevator can have vital consequences for flight safety. In this work, the performance of classical control approach against asymmetric elevator failures is investigated and it is shown that this approach is insufficient in the case of such a failure. Then,...

This paper is concerned with the flexibility in the closed loop pole location when solving the $H_2$ optimal control problem (also called the $H_2$ optimal disturbance attenuation problem) by proper measurement feedback. It is shown that there exists a precise and unique set of poles which is present in the closed loop system obtained by any measurement feedback solution of the $H_2$ optimal control problem. These “$H_2$ optimal fixed poles” are characterized in geometric as well as structural terms. A procedure...

Mathematics Subject Classification: 26A33; 93C15, 93C55, 93B36, 93B35, 93B51; 03B42; 70Q05; 49N05This paper proposes a novel method to design an H∞ -optimal fractional order PID (FOPID) controller with ability to control the transient, steady-state response and stability margins characteristics. The method uses particle swarm optimization algorithm and operates based on minimizing a general cost function. Minimization of the cost function is carried out subject to the H∞ -norm; this norm is also...

This paper examines the problem of designing a robust ${}_{\infty }$ fuzzy controller with -stability constraints for a class of nonlinear dynamic systems which is described by a Takagi-Sugeno (TS) fuzzy model. Fuzzy modelling is a multi-model approach in which simple sub-models are combined to determine the global behavior of the system. Based on a linear matrix inequality (LMI) approach, we develop a robust ${}_{\infty }$ fuzzy controller that guarantees (i) the ₂-gain of the mapping from the exogenous input noise to the...