Multi-mode switching between controllers corresponding to different modes of operation is needed in those cases when the transition from one mode to another results in substantial flight-critical variations in the aircraft dynamics. To address this problem, a general framework for multi-modal flight control is proposed. The framework is based on the Multiple Models, Switching and Tuning (MMST) ...

Kalman and PID controller are used to design UAV (Unmanned Air Vehicles) formation flight control system for speed and pitch angle. UAV adjusted the PID parameters to realize control stability of UAV flight. The simulation results will show that Kalman and PID controller have better dynamic performance than the traditional controller in respect of simpler design, higher precision, easier implem...

In automatic flight control system or autopilots, multiple specifications criteria are needed to be satisfied concurrently, such as good holding (small static altitude holding error), fast response, smooth transition (less oscillation, overshoot). So how to design the MSS (Multiple Simultaneous Specification) controller effectively and practically is a very significant and challenging job. Liu ...

Honey bees move through a series of in-hive tasks (e.g., "nursing") to outside tasks (e.g., "foraging") that are coincident with physiological changes and higher levels of metabolic activity. Social context can cause worker bees to speed up or slow down this process, and foragers may revert back to their earlier in-hive tasks accompanied by reversion to earlier physiological states. To investig...

We study the dynamics of a rigid, symmetric wing that is flapped vertically in a fluid. The motion of the wing in the horizontal direction is not constrained. Above a critical flapping frequency, forward flight arises as the wing accelerates to a terminal state of constant speed. We describe a number of measurements which supplement our previous work. These include a a study of the initial tran...

This paper describes the modeling, control and hardware implementation of an experimental tilt-rotor aircraft. This vehicle combines the high-speed cruise capabilities of a conventional airplane with the hovering capabilities of a helicopter by tilting their four rotors. Changing between cruise and hover flight modes in midair is referred to transition. Dynamic model of the vehicle is derived b...

A method is presented for the stress analysis of flight vehicles under different flight conditions including gust and control surface deflection (or maneuver) using the governing equations of rigid-body motions and elastic deformations. The Lagrangian approach is used to derive the governing equations of motions. For this purpose, the basic equations of motions are derived in terms of potential...

Aerospace In article number 2203920, Lyndsey McMillon-Brown, Sayanatani Ghosh, and co-workers report on the first long duration space flight of a metal halide perovskite photoactive layer International Space Station. Post-flight analysis reveals that samples exhibit superior photo-stability, no irreversible radiation damage, suppressed structural phase transition temperature, broadening photovo...