Method and system for stabilizing a payload

Abstract

A carrier includes a stator configured to be coupled to a base support, a frame operably coupled to the stator via a plurality of piezoelectric actuators, and at least one inertial sensor attached to the frame. The stator includes a spherical surface. The frame is configured to rotate relative to the stator about one or more rotational axes. Rotation of the frame is effectuated via the plurality of piezoelectric actuators. The inertial sensor is configured to detect a motion of the frame.

What is claimed is: 
     
         1 . A carrier comprising:
 a stator configured to be coupled to a base support, the stator comprising a spherical surface;   a frame operably coupled to the stator via a plurality of piezoelectric actuators, wherein the frame is configured to rotate relative to the stator about one or more rotational axes, and wherein rotation of the frame is effectuated via the plurality of piezoelectric actuators; and   at least one inertial sensor attached to the frame, wherein the inertial sensor is configured to detect a motion of the frame.   
     
     
         2 . The carrier of  claim 1 , wherein the inertial sensor comprises at least one of a gyroscope or an accelerometer. 
     
     
         3 . The carrier of  claim 2 , wherein the inertial sensor is configured to detect at least one of a position, an attitude, an angular velocity, or an angular acceleration of the frame. 
     
     
         4 . The carrier of  claim 2 , wherein the motion of the frame is detected without using an optical encoder or a magnetic field sensor. 
     
     
         5 . The carrier of  claim 1 , wherein the frame is configured to support one or more payloads, a position of at least one of the one or more payloads being controlled based on the detected motion of the frame. 
     
     
         6 . The carrier of  claim 1 , wherein the one or more payloads comprise at least one camera. 
     
     
         7 . The carrier of  claim 6 , wherein the at least one camera includes an omnidirectional camera. 
     
     
         8 . The carrier of  claim 1 , wherein the at least one inertial sensor is calibrated by obtaining: (1) a relative position between the frame and the base support, or (2) a relative position between the frame and a reference plane. 
     
     
         9 . The carrier of  claim 1 , wherein the plurality of piezoelectric actuators are configured to effect a movement of the frame based on a target angle. 
     
     
         10 . The carrier of  claim 9 , wherein one or more processors are individually or collectively configured to determine an input torque to the frame based on the target angle. 
     
     
         11 . The carrier of  claim 10 , wherein the input torque is determined using a feedback control loop. 
     
     
         12 . The carrier of  claim 11 , wherein the feedback control loop is implemented using a proportional-integral-derivative (PID) controller comprising the one or more processors. 
     
     
         13 . The carrier of  claim 1 , wherein the stator is rigidly coupled to the base support. 
     
     
         14 . The carrier of  claim 1 , wherein the one or more rotational axes comprise at least one of a pitch axis, roll axis, or yaw axis. 
     
     
         15 . The carrier of  claim 1 , wherein the stator is rotatably coupled to the base support via a motor. 
     
     
         16 . The carrier of  claim 1 , wherein the piezoelectric actuators are uniformly distributed along a circle of the spherical surface of the stator. 
     
     
         17 . The carrier of  claim 16 , wherein the circle is a small circle or a great circle of the spherical surface. 
     
     
         18 . The carrier of  claim 16 , wherein:
 the stator is rotatable relative to the base support about a yaw axis using a motor; and   the plurality of piezoelectric actuators are configured to rotate the frame relative to the stator about a roll axis and a pitch axis.   
     
     
         19 . The carrier of  claim 16 , wherein:
 the stator is rigidly attached to the base support; and   the plurality of piezoelectric actuators are configured to rotate the frame relative to the stator about a roll axis, a pitch axis, and a yaw axis.   
     
     
         20 . The carrier of  claim 16 , wherein the circle has a smaller diameter in a scenario where the stator is rigidly attached to the base support than in a scenario where the stator is rotatable relative to the base support about a yaw axis using a motor.