Nonlinear control design for slightly non-minimum phase systems: Application to V/STOL aircraft

Chaotic behaviors of an underactuated system in the trajectory tracking task

“…The most popular method of tracking control of underactuated systems with the input coupling effect is based on the change of variables that converts this problem into noncoupled [4]. Then, some accelerations are separately controlled by inputs and some stay without control (selective control method).…”

Robust and Active Trajectory Tracking for an Autonomous Helicopter Under Wind Gust

“…To simplify this study, the demonstration is done with one input and one output as in (Hauser et al (1992)) and the result is applicable for other outputs. Let us first define the altitude error using equations (32) , (37) and the control (39): we can write: (69) Where A is a stable matrix determined by pole placement, and η represents the zero dynamics of our system, = γ − γ eq , where γ eq = −124.63rad/s is the equilibruim of the main rotor angular speed :…”

Global configuration stabilization for the VTOL aircraft with strong input coupling

“…The simplified dynamics of the VTOL aircraft is given in [2] as the following (1) where 6 = 0, is the roll angle and the VTOL moves in a vertical (x 1 ; y 1 ) plane. In [1], approximate linearization techniques were used which ignore the coupling between the first two second-order subsystems in (1) and the (; ! )-subsystem and then treat the system as a slightly nonminimum phase system.…”