μ-synthesis is a NP-hard optimization problem based on the generalized Robust Control framework which manages to find controller fulfills both robust stability and performance. In order solve such problems, nonsmooth techniques are employed nearly-optimal parameters values. However, free available for tuning must be involved only in classical arithmetic operations, leads fractional-order operat...

The paper presents a general algorithm for the specification of a screw machine geometry. The conjugancy condition was solved numerically which thereby enables a variety of primary arc curves to be introduced. In addition, an optional numerical derivation of primary arcs enables any analytical function and even discrete point functions to be used for the primary arc. The approach also simplifie...

The paper proposes a methodology for reliable design and maintenance of wind turbine rotor blades using a condition monitoring approach and a damage tolerance index coupling the material and structure. By improving the understanding of material properties that control damage propagation it will be possible to combine damage tolerant structural design, monitoring systems, inspection techniques a...

This paper presents real – time control of the Twin Rotor MIMO System laboratory model. The objective laboratory model is a multivariable nonlinear unstable system of high order. It is not possible to stabilize the system and satisfactorily track reference signals using classical controllers with fixedly set parameters. Two methods based on self – tuning control utilizing adaptive approach are ...

In this paper, an angular tracking control based on adaptive super twisting algorithm (ASTA) for a Twin Rotor System is presented. With the aim of implementing the ASTA control and taking into consideration the difficulties of measuring some of its states, a Nonlinear Extended State Observer (NESO) is employed to estimate the vector state and furthermore unmeasured dynamics. This scheme increas...

ii Dedicated to my dearest parents iii ACKNOWLEDGEMENTS I would like to express my gratitude to my advisor, Dr. Ernest A. Mendrela, for his invaluable suggestions and constant patience in guiding me throughout the research. His technical advice and expertise in the field provided me the motivation towards successful completion of this thesis. Shahab Mehraeen, for sparing time out of their busy ...

This article presents the design of a novel decentralized nonlinear multivariate control scheme for an underactuated, nonlinear and multivariate laboratory helicopter denominated the twin rotor MIMO system (TRMS). The TRMS is characterized by a coupling effect between rotor dynamics and the body of the model, which is due to the action-reaction principle originated in the acceleration and decel...

This paper presents a comparative study of neural observers for TRMS. These are Chebyshev neural network based observer (CNN) and Multi-layer feedforward neural network (MLFFNN) observer. TRMS is a highly non-linear system having mutual interference between two rotors, it is trivial to design an effective controller for the TRMS to reach the desirable yaw and pitch angles. All the states are no...

This paper deals with model predictive control (MPC) approach for a 2 DOF (degree of freedom) helicopter. The main objective is to stabilize beam of the 2DOF helicopter with respect to pitch and yaw angles. Development of controller for 2DOF helicopter is challenging because of its coupling effects between two axes and also due to its highly nonlinear characteristics. An accurate model of the s...

Recent interest in natural refrigerants has created a new impetus for studies of CO2 as a working fluid in vapour compression systems for refrigeration and air conditioning. Two major drawbacks to its use are the very high pressure differences required across the compressor and the large efficiency losses associated with the throttling process. To overcome the throttle losses, a number of propo...