Robust and autonomous docking and recharging of quadrotors

Autonomous docking and recharging hardware for quadrotor drones.

A method of docking and recharging using a base station and a station-mating frame onthe multicopter. The base station includes an upward-facing camera that is used by a docking controller to detect the presence, position, and orientation of a frame, with infraredlight-emitting diodes arranged in a predefined pattern. The controller of the base station acts to emit wireless signals to the multicopter to guide the multicopter with its station-mating frame to a predefined position above the base station. The controller transmits a wireless signal to the multicopter to reduce thrust, and the multicopter lowers itself onto a sloped receiving surface that may be arranged in a crown pattern to provide passive gravity-driven centering, which causes the station-mating frame to slide to a lowest vertical point of the receiving assembly. A locking mechanism engages to lock the frame in place and provide electrical contact for recharging.

BRIEF DESCRIPTION OF THE DRAWINGS(1) FIG. 1 is functional block diagram of a docking and charging system showing use of a station-mating frame attached to aUAV (e.g., a quadrotor) in combination with a base or docking station to achieve autonomous docking and charging of the UAV's battery;(2) FIG. 2 is a top view of a receiving assembly for use with a docking or base station of the present description such as with the base station of FIG. 1 and showing the crown pattern (or peak and valley arrangement) of upper edges of sidewalls along with receiving slots or grooves for a station-mating frame on alanding UAV and an upward facing camera;(3) FIG. 3 is a side perspective view of the receiving assembly of FIG. 2;(4) FIG. 4 is another side perspective view of the receiving assembly of FIGS. 2 and 3 with a quadrotor carrying a station-mounting frame received and locked within the assembly;(5) FIG. 5 is an enlarged view of the receiving assembly of FIGS. 2and 3 showing details of one of the receiving slots/grooves illustrating a locking mechanism in the engaged position and showing a charging contact of the receiving assembly extending into the receiving slot;(6) FIG. 6 is a flow diagram for a vision (or frame sensing and pose determination) method of the present description such as may be carried out by theframe sensing module of FIG. 1;(7) FIG. 7 illustrates a flow diagram for the steps for initializing a Kalman Filter as part of the method or process of FIG. 6;(8) FIG. 8 ill