iii NOMENCLATURE C r modal damping, lb-sec/ft C T rotor thrust coefficient H transfer matrix relating the vibratory hub loads to the balance signals; inverse of the dynamic calibration matrixˆH complex representation of H i −1 Im imaginary part of a complex number K r modal stiffness, lb/ft M r modal mass, slug nP n-per-rev or n per rotor revolution Re real part of a complex number s frequency ...

This research is focused on the definition, analysis, and numerical testing of an effective nonlinear orbit control technique tailored to compensating perturbations, as well possible errors at injection low- medium-altitude Earth-orbit satellites. A general, systematic approach real-time presented, under assumption that satellite interest equipped with a steerable throttleable low-thrust propul...

[1] Even though the rheology of thrust wedges is mostly frictional, a basal ductile decollement is often involved. By comparison with purely frictional wedges, such brittleductile wedges generally display anomalous structures such as backward vergence, widely spaced thrust units, and nonfrontward sequences of thrust development. Laboratory experiments are used here to study the deformation of b...

Abstract Nonlinear orbit control with the use of low-thrust propulsion is proposed as an effective strategy for autonomous guidance a space vehicle directed toward Moon. Orbital motion described in ephemeris model, inclusion most relevant perturbations. Unfavorable initial conditions, associated weak, temporary lunar capture, are considered, representative conditions that may be encountered rea...

With the development of aircraft gas turbine engine, a control system should be able to achieve effective thrust gain better operability. The main contribution this paper is develop novel direct approach based on an improved model predictive method through strategy that reduces dimension sequence. It can not only normal tasks but also maximize level within safe operation boundaries. Only action...

The direct transcription method has been used to solve many challenging optimal control problems. One such example involves the calculation of a low thrust orbit transfer between libration point orbits. The recent implementation of high order discretization techniques is first described and then illustrated by computing optimal low thrust trajectories between orbits about the L1 and L2 Earth-Mo...