Aerial unit and method for elevating payloads

A system, comprising:

• a ground unit;
• an aerial unit;
• and a connecting element arranged to connect the ground unit to the aerial unit;
• wherein the ground unit comprises:
• a connecting element manipulator, for altering an effective length of the connecting element;
• wherein the effective length of the connecting element defines a distance between the ground unit and the aerial unit;
• a ground unit controller for controlling the connecting element manipulator;
• and a positioning unit arranged to image the aerial unit and to generate metadata about a location of the aerial unit;
• wherein the aerial unit comprises:
• a first propeller;
• a frame;
• a first propeller motor that is configured to rotate the first propeller about a first axis, wherein the first propeller motor is connected to the frame;
• and at least one steering element;
• wherein at least one of the ground unit and the aerial unit comprises a controller that is arranged to control, at least in response to the metadata, at least one of the first propeller motor and the at least one steering element to affect at least one of the location of the aerial unit and the orientation of the aerial unit;
• wherein the frame at least partially surrounds the propeller;
• wherein the system further comprises additional propellers, additional frames and additional propeller motors that are arranged to rotate the additional propellers;
• wherein the additional frames at least partially surround the additional propellers;
• wherein the additional frames are coupled to the frame by coupling elements that facilitate a movement of the additional frames between an open configuration and a close configuration;
• wherein when positioned at the open configuration each additional propeller is positioned outside the frame so that the frame does not overlap any of the additional frames;
• wherein when positioned at the close configuration the additional propellers and the frame overlap;
• wherein the controller is further arranged to control the additional propeller motors.