Flying vehicle systems and methods

1. An unmanned aerial vehicle, comprising:

a chassis;

a power supply mounted to the chassis;

a control system operable to receive power from the power supply;

at least one rotor operable to generate lift under control of the control system; and

a winch mounted to the chassis, the winch comprising:

a reel having a line wound thereon, the line having a free end; and

a motor operable to rotate the reel under control of the control system to thereby cause the line to wind onto and off of the reel, thereby causing the free end of the line to raise and lower;

wherein the control system is configured to operate the motor to cause the free end of the line to:

lower toward a surface below the unmanned aerial vehicle at a controlled speed as the free end of the line passes through an upper portion of the distance;

accelerate toward the surface as the free end of the line passes through a first portion of the distance; and

decelerate as the free end of the line passes through a lower portion of the distance; and

wherein the first portion of the distance is between the upper portion of the distance and the lower portion of the distance.

2. The unmanned aerial vehicle of claim 1 , wherein the controlled speed is a constant speed.

3. The unmanned aerial vehicle of claim 1 , further comprising a position sensor in communication with the control system;

wherein the line extends through an armature such that the armature moves between a first position and a second position in response to a pulling force being applied to the free end of the line;

wherein movement of the armature between the first position and the second position alters an output of the position sensor; and

wherein the control system is configured to determine a loaded/unloaded condition of the winch based upon the output of the position sensor.

4. The unmanned aerial vehicle of claim 1 , further comprising a sensor operable to detect a loaded/unloaded condition of the line;

wherein the control system is further configured to operate the motor to cause the free end of the line to raise in response to information generated by the sensor indicating that the line is unloaded.

5. An unmanned aerial vehicle, comprising:

a chassis;

a power supply mounted to the chassis;

a control system operable to receive power from the power supply;

at least one rotor operable to generate lift under control of the control system; and

a motor operable to lower a free end of a line, wherein the free end of the line is operable to engage a parcel to be delivered by the unmanned aerial vehicle;

wherein the control system is configured to operate the motor to cause the free end of the line to:

lower toward the delivery surface at a controlled speed as the free end of the line passes through an upper portion of the distance;

accelerate toward a delivery surface as the free end of the line passes through a first portion of a distance between the unmanned aerial vehicle and the delivery surface; and

decelerate as the free end of the line passes through a lower portion of the distance; and

wherein the first portion of the distance is between the upper portion of the distance and the lower portion of the distance.

6. The unmanned aerial vehicle of claim 5 , further comprising a downward-facing ranging-and-detection device;

wherein the control system is configured to determine the distance between the unmanned aerial vehicle and the delivery surface based upon information generated by the ranging-and-detection device.

7. The unmanned aerial vehicle of claim 5 , further comprising a reel on which a portion of the line is wound;

wherein the motor is operable to lower the free end of the line by rotating the reel.

8. The unmanned aerial vehicle of claim 5 , further comprising a load sensor operable to detect a loaded/unloaded condition of the line;

wherein the control system is further configured to operate the motor to cause the free end of the line to raise in response to information generated by the sensor indicating that the line is unloaded.

9. The unmanned aerial vehicle of claim 5 , further comprising a carriage operable to hold the parcel;

wherein the control assembly is further configured to cause the carriage to release the parcel.

10. A method of operating an unmanned aerial vehicle (UAV), the method comprising:

navigating the UAV to a destination comprising a designated surface, wherein the UAV comprises a winch including a line having a delivery load releasably coupled to a free end of the line;

determining a distance between the UAV and the designated surface;

operating the winch to lower the delivery load toward the designated surface, comprising:

limiting a delivery speed of the delivery load through a first zone of the distance;

increasing the delivery speed of the delivery load through a second zone of the distance, wherein the second zone is located below the first zone; and

reducing the delivery speed of the delivery load through a third zone of the distance, wherein the third zone is located below the second zone.

11. The method of claim 10 , further comprising maintaining the UAV at a nominally constant hover height while operating the winch to lower the delivery load toward the designated surface.

12. The method of claim 10 , wherein the navigating, the determining, and the operating are performed by a control system of the UAV.

13. The method of claim 10 , further comprising releasing the delivery load from the free end of the line in response to the delivery load landing on the designated surface; and

sensing release of the delivery load via a load sensor of the winch.

14. The method of claim 13 , wherein the load sensor comprises a position sensor associated with a movable armature through which the line extends, and wherein sensing release of the delivery load comprises sensing a position of the armature.

15. The method of claim 14 , further comprising operating the winch to raise the free end of the line in response to sensing release of the delivery load.

16. The method of claim 10 , wherein the UAV further comprises a ranging-and-detection device; and

wherein determining the distance between the UAV and the designated surface comprises determining the distance based upon information generated by the ranging-and-detection device.

17. The method of claim 10 , further comprising releasing the delivery load from a carriage of the UAV;

wherein at least a portion of the operating the winch to lower the delivery load toward the designated surface is performed after releasing the delivery load from the carriage.

18. The unmanned aerial vehicle of claim 1 , wherein the control system comprises a downward-facing ranging-and-detection device, and is operable to determine the distance between the unmanned aerial vehicle and the surface based upon information generated by the ranging-and-detection device.