Abstract: An unmanned airborne vehicle (UAV) recovery system for in-flight recovery of a fixed wing UAV includes a catching device and a plurality of hover-capable drones, such as multi-rotors. The catching device is for catching the fixed wing UAV via a hook system during flight of the fixed wing UAV and takes the form of a line between the recovery drones. The recovery drones are arranged to support the catching device as it spans a gap in a horizontal orientation with the catching device suspended between at least two recovery drones that are in flight and spaced apart horizontally from each other either side of the gap. During a recovery operation the recovery drones co-ordinate their movement to adopt a flight path relative to a flight path of the fixed wing UAV to define a virtual runway for interception of the fixed wing UAV by the recovery system.

Abstract: A system for testing a vessel control system includes sensors on board the vessel to send one or more sensor signals over a signal line to the control system; command input devices on board the vessel to send one or more of desired position, course, velocity, etc. over a command signal line to the control system; an algorithm in the control system to compute control signals to based on sensor data, communication lines for sending of one or more simulated signals and/or simulated command signals from a remote test laboratory to the control system; and a simulator including an algorithm for the simulation of the new dynamic state of a vessel model based on a previous state, the control signals, and the dynamic parameters of the vessel. The control system continues to compute the control signals to achieve at least one of desired position, course, velocity, etc. based on real and/or simulated sensor signals and real and/or simulated command signals.

Abstract: A system for testing a control system in a vessel, comprising: sensors on board the vessel; command input devices on board the vessel to send desired position, course, velocity; an algorithm in the control system for the computation of control signals to the vessel actuators; communication lines for sending simulated command signals from a remote test laboratory to the control system; a simulator including an algorithm for the simulation of the new dynamic state of a vessel model based on a previous state; where the communication line is arranged for sending back the new simulated stare of the vessel model in the form of simulated sensor signals for continued computation to achieve desired position, course, velocity; and where the communication line is sending the response from the control system to the remote test laboratory.

Abstract: A method for verifying a control system (2) of a vessel (4), in which said control system (2) in its operative state receives sensor signals (7) from sensors (8) and command signals (9) from command input devices (10), and as a response provides control signals (13) to actuators (3) in order to maintain a desired position, velocity, course or other state of said vessel (4), characterized by the following steps: during a time (t0), disconnecting the reception of real sensor signals (7a, 7b, 7c, . . . ) and replacing said real sensor signals by a test sequence (T0) of artificial measurements (7a?, 7b?, 7c?, . . .