Abstract: To replace a depleted battery in a drone with a fresh battery, the drone first lands on the exchange and charging system, aligned between two battery holders. A freshly charged battery, in a docking bay in one battery holder, is then moved against the drone's depleted battery. The depleted battery, in turn, is moved out of the drone into the other battery holder, and the fresh battery takes its place. While in the battery holders, the batteries are charged. After a battery exchange, the battery holders track round so that another battery and vacant docking bay are brought into place for a subsequent exchange.

Abstract: A flight plan for an unmanned aerial vehicle is created based on a target to inspect. The plan can be based on the data obtained from one or more prior inspection flights for the same target. Flight plans can be automatically suggested to the users based on the analysis of data obtained during prior inspection flights.

Abstract: Points of interest are added to a flight plan overlaid on a map. Camera switch-on and switch-off locations are automatically added to the nearest leg of the flight plan. An observation triangle joining the point of interest and the camera on and off locations is displayed so that the user can easily visualize the range of angles from which the point of interest is viewed. The triangle may be colored and/or partially transparent. Adjustment of the camera on and off locations is possible, with the system automatically adjusting the observation triangle. In a similar way, lines of interest and curves of interest may be added to the flight plan.

Abstract: A rotor arm assembly has a mechanical alignment and electrical connector for fitting to an unmanned aerial vehicle (UAV). The UAV has a corresponding fitting for aligning the rotor arm assembly, making an electrical connection with it and retaining it in position. Such rotor arm assemblies are easily and quickly replaced due to their modular construction. UAVs with this construction are easily transported and stored.

Abstract: A return-to-home command for securing an unmanned aerial vehicle (UAV) from flying away. Flight plan updates that may be uploaded to the UAV can be interrupted at any time by uploading a modified flight plan or by instructing the UAV to pause while manual flight commands are given. The modifications to the original flight plan always ensure that a return-to-home step is present in the instructions on board the UAV, so that if the radio communications link between the remote controller and the UAV is lost, the UAV will fly home.