Vision-based control for helicopter ship landing with handling qualities constraints

Adaptive nonlinear relative motion control of quadrotors in autonomous shipboard landings

“…Assumption 2. The pose motion information of the quadrotor r, v, σ, ω and the relative pose information r e , v e , σ e , ω e between two vehicles are measured exactly by the measurement devices mounted on the bodies of quadrotor [10]- [14].…”

“…Consider the relative position model in ( 9) and (10). Define the virtual position error re = Rr e − η and virtual velocity error ve = Rv e − α − η with an auxiliary state η and virtual control input α.…”

“…Remark 8. For the dynamical model of relative position approaching phase including ( 9), (10), and the attitude dynamics in (1), the proposed relative position approaching controller is constructed by the thrust input (25), torque input (40), auxiliary system (23), and command filter (29) with the positive tunable parameters…”

“…Theorem 1. Consider the relative position dynamics (9), (10) and the quadrotor's attitude dynamics shown in the last two subequations of (1) under the Assumptions 1 and 2. Design the auxiliary system (23), control thrust (25), and control torque (40) for the quadrotor under the condition (28).…”

“…Then, the study in [7] allowed precise controlled landing in difficult situations by connecting the moving shipboard and the aircraft with a physical tether. Based on the image features as references while filtering its movements to get a smooth helicopter trajectory compared to the targeted ship, a method to set two controllers based on a translational rate command law and a common advanced speed control law for modern helicopters were presented by [10]. Furthermore, to improve the landing precision of the helicopter, a vision-based auto landing system was proposed in [11] for unmanned helicopter on a ship.…”