Tracking a ballistic missile in its reentry phase is one of the missile defence challenges as these reentry vehicles penetrate with large aerodynamic loads and sudden decelerations from exoatmospheric to endoatmospheric phase. With the advent of anti-ballistic missiles, the main goal of missile defence systems is to track the reentry vehicle to locate them precisely for allowing midair altitude...

An integrated Autopilot-and Guidance Algorithm is developed using Higher Order Sliding Mode Control, for interceptors steered by combination of aerodynamic lift, sustainer thrust and center of gravity divert thrusters. A smooth HOSM guidance generates flight path trajectory angular rates and attitude rate commands. The attitude rate maneuvers are aimed at producing desired aerodynamic lift and ...

This paper describes recent development on the design of the flight control system for a Micromechanical Flying Insect (&PI), a 10-25mm (wingtipto-wingtip) device capable of sustained autonomous flight. High level attitude control is considered. Based on our previous work [l], in which the complex time-varying component of aerodynamic forces are treated as extemal disturbances, a nominal state-...

Abstract This paper will discuss a method of bluff body noise control that utilises the phenomenon of aerodynamic interference. This technique uses a second body (not necessarily bluff) that is placed in the wake of the bluff body whose noise we wish to control. Through proper understanding of the wake dynamics, the amplitude and phase of the noise from the downstream body can be controlled so ...

Analytical and numerical simulations are carried out in order to identify physical parameters affecting acoustic and motion control by viscoelastic piezo-electric and material damping. Numerical simulations in terms of critical parameters, such as relaxation functions of the structure and piezo-electric devices, aerodynamic coefficients, Mach number, are carried out to evaluate their sensitivit...

The effects of viscoelastic piezoelectric damping on the control of aerodynamic derivatives and of aileron reversal time retardation is formulated and evaluated. It is shown that significant control can be achieved with devices which add insignificant weight to flight vehicles, i. e. creep divergence and aileron reversal can be delayed in time.

Small fixed-wing UAS that are able to hover combine the station keeping abilities of a rotary wing platform and the extended range of conventional aircraft. Current autopilots for these vehicles rely on inertial measurements plus airspeed to transition from forward flight to hover, accumulating appreciable position error during the transition. Once in hover, a combination of inertial and GPS da...

In the analysis of flexible flapping wings of insects, the aerodynamic outcome depends on the combined structural dynamics and unsteady fluid physics. Because the wing shape and hence the resulting effective angle of attack are a priori unknown, predicting aerodynamic performance is challenging. Here, we show that a coupled aerodynamics/structural dynamics model can be established for hovering,...

Advanced missiles employ multiple actuators to enhance maneuverability and to improve the intercept probability against highly maneuverable targets. Actuators employed in such missiles include aerodynamic control surfaces and reaction jets. While the usage of aerodynamic surfaces are not generally constrained, reaction jet usage has to be minimized due to the limited amount of fuel available on...

The use of flexible mode control implemented through the use of aerodynamic surfaces is examined for two case vehicles: a magnetically levitated vehicle and a towed aerodynamic vehicle. A summary of the aerodynamics of trapezdoial and annular wings is presented first, followed by an analysis of the modal characteristics of the test vehicles. LQR design methods using the flexible mode and its ra...