Foldable uav

Abstract

An unmanned aerial vehicle (UAV) includes a central body having a first side and a second side opposite to the first side, and a first arm and a second arm extendable from the central body and respectively disposed on the first side and the second side. Each arm of the first arm and the second arm includes a plurality of sections and holds a set of rotor blades via a rotor shaft, and the plurality of sections includes a first section and a second section rotatably connected to the first section. The each arm of the first arm and the second arm is configured to transform between a flight configuration in which the second section of the each arm is extended away from the central body and a compact configuration in which the plurality of sections of the each arm are located at a corresponding side of the central body.

What is claimed is: 
     
         1 . An unmanned aerial vehicle (UAV), the UAV comprising:
 a central body having a first side and a second side opposite to the first side; and   a first arm and a second arm extendable from the central body and respectively disposed on the first side and the second side, wherein each arm of the first arm and the second arm comprises a plurality of sections and holds a set of rotor blades via a rotor shaft, the plurality of sections comprising a first section and a second section rotatably connected to the first section,   wherein each arm of the first arm and the second arm is configured to transform between:
 a flight configuration in which the second section of the each arm is extended away from the central body, and 
 a compact configuration in which the plurality of sections of the each arm are located at a corresponding side of the central body, such that the second section and the corresponding set of rotor blades are substantially parallel to one another and substantially parallel to the corresponding side of the central body, and each rotor shaft is arranged adjacent to or at a center of the corresponding side of the central body. 
   
     
     
         2 . The UAV of  claim 1 , wherein:
 the first arm and the second arm are extendable from the central body using one or more actuators;   the each arm is configured to support one or more propulsion units carrying the set of rotor blades; and   the each arm of the plurality of arms is configured to connect to one of the one or more actuators via a linkage mechanism, wherein the one of the one or more actuators is configured to actuate the linkage mechanism between the flight configuration and the compact configuration.   
     
     
         3 . The UAV of  claim 2 , wherein at least two connecting bars of the linkage mechanism are disposed at an angle relative to one another when the each arm is in the flight configuration. 
     
     
         4 . The UAV of  claim 3 , wherein the angle is an obtuse angle. 
     
     
         5 . The UAV of  claim 2 , wherein at least two connecting bars of the linkage mechanism are disposed at an angle relative to one another when the each arm is in the compact configuration. 
     
     
         6 . The UAV of  claim 5 , wherein the angle is an acute angle. 
     
     
         7 . The UAV of  claim 2 , wherein the each arm includes a plurality of foldable sections movable connected with each other via a connecting mechanism. 
     
     
         8 . The UAV of  claim 7 , wherein a length of a first foldable section having a proximal end of the each arm is greater than a length of a second foldable section having a distal end of the respective arm. 
     
     
         9 . The UAV of  claim 7 , wherein at least one foldable section of the each arm comprises a hollow cavity along its longitudinal axis, such that another foldable section of the respective arm movably connected to the at least one foldable section is received in the hollow cavity when the respective arm is in the compact configuration or extended out of the hollow cavity when the respective arm is in the flight configuration. 
     
     
         10 . The UAV of  claim 8 , wherein the connecting mechanism includes a first connecting mechanism and a second connecting mechanism, the proximal end is connected to the central body via the first connecting mechanism, and the distal end is connected to and configured to support a corresponding propulsion unit. 
     
     
         11 . The UAV of  claim 10 , wherein:
 the first connecting mechanism includes an actuator mechanism and the second connecting mechanism includes a chain mechanism,   actuation of the actuator mechanism causes the each arm to be folded toward a corresponding side of the central body such that the first foldable section and the second foldable section are parallel to each other to transform the respective arm into the compact configuration, and   reverse actuation of the actuator mechanism causes the each arm to be extended away from the corresponding side of the central body to transform the respective arm into the flight configuration.   
     
     
         12 . The UAV of  claim 11 , wherein the chain mechanism comprises at least one of: a cable, a chain, a belt, or a spring. 
     
     
         13 . The UAV of  claim 11 , wherein the chain mechanism pushes the second foldable section of the each arm to rotate relative to the first foldable section to transform between the flight configuration and the compact configuration. 
     
     
         14 . The UAV of  claim 2 , wherein a first end of the linkage mechanism is rotatably connected to the each arm and a second end of the linkage mechanism is rotatably connected to the one of the one or more actuators. 
     
     
         15 . The UAV of  claim 14 , wherein the one or more actuators are arranged on the central body. 
     
     
         16 . The UAV of  claim 14 , wherein the one of the one or more actuators is configured to drive one or more connecting bars of the linkage mechanism that are connected to the one of the one or more actuators. 
     
     
         17 . The UAV of  claim 2 , wherein the linkage mechanism comprises a first joint for connecting to the one arm and a second joint for connecting to the one of the one or more actuators and wherein a distance between the first joint and the second joint is changed as the linkage mechanism is actuated between the flight configuration and the compact configuration. 
     
     
         18 . The UAV of  claim 17 , wherein the distance between the first joint and the second joint is substantially equal to a length of the linkage mechanism when the linkage mechanism is in the flight configuration. 
     
     
         19 . The UAV of  claim 17 , wherein the distance between the first joint and the second joint is less than a length of any one of connecting bars of the linkage mechanism in the compact configuration. 
     
     
         20 . The UAV of  claim 2 , wherein the linkage mechanism comprises at least one of a two-bar linkage mechanism or a four-bar linkage mechanism.