Method and system for stabilizing a payload

Patent metadata

Field	Value
Publication number	US-10330254-B2
Application number	US-201816112163-A
Country	US
Kind code	B2
Filing date	Aug 24, 2018
Priority date	Feb 26, 2016
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

An apparatus includes a carrier, one or more first sensors, one or more second sensors, and one or more processors. The carrier includes a first frame and a second frame. A payload is affixed to the first frame. The second frame is rotatably coupled to a movable object. The one or more first sensors are disposed on the payload and configured to measure one or more motion characteristics of the payload. The one or more second sensors are disposed on the carrier and configured to measure one or more motion characteristics of the carrier. The one or more processors are configured to determine an input torque based on the one or more motion characteristics of the payload, determine an estimated disturbance torque based on the one or more motion characteristics of the carrier, and calculate an output torque based on the input torque and the estimated disturbance torque.

First claim

What is claimed is:

1. An apparatus for controlling an attitude of a payload, comprising:
a carrier comprising:
a first frame, the payload being affixed to the first frame; and
a second frame rotatably coupled to a movable object;

one or more first sensors disposed on the payload and configured to measure one or more motion characteristics of the payload;
one or more second sensors disposed on the carrier and configured to measure one or more motion characteristics of the carrier; and
one or more processors individually or collectively configured to:
determine an input torque based on the one or more motion characteristics of the payload;
determine an estimated disturbance torque based on the one or more motion characteristics of the carrier; and
calculate an output torque based on the input torque and the estimated disturbance torque, the output torque being configured to effect movement of the second frame to achieve a desired attitude of the payload.

2. The apparatus of claim 1 , further comprising:
the movable object; and
a damping element disposed between the movable object and the carrier;
wherein the carrier is a multi-axis gimbal.

3. The apparatus of claim 2 , wherein the second frame is coupled to the movable object via the damping element.

4. The apparatus of claim 3 , wherein the second frame is coupled to the damping element via a coupling structure, and the one or more second sensors are disposed on the coupling structure.

5. The apparatus of claim 4 , wherein the one or more second sensors are provided on a flexible printed circuit (FPC) attached to the coupling structure.

6. The apparatus of claim 1 , wherein the second frame is coupled to a motor configured to rotate the second frame about a yaw axis and the one or more second sensors are disposed on the second frame or the motor.

7. The apparatus of claim 1 , wherein the estimated disturbance torque is determined by inputting the one or more motion characteristics of the carrier into a predefined dynamics-based model of the carrier.

8. The apparatus of claim 7 , wherein the one or more motion characteristics of the carrier comprise at least a linear acceleration or an angular acceleration of the carrier.

9. The apparatus of claim 7 , wherein the one or more motion characteristics of the carrier are associated with one or more motion characteristics of the second frame.

10. The apparatus of claim 1 , wherein the estimated disturbance torque is calculated with respect to a rotatable joint on the second frame, the rotatable joint being configured to couple the second frame to the movable object.

11. The apparatus of claim 1 , wherein the estimated disturbance torque is refined using a proportional-derivative (PD) controller to obtain a refined disturbance torque.

12. The apparatus of claim 11 , wherein the estimated disturbance torque is refined by applying one or more filters to the estimated disturbance torque.

13. The apparatus of claim 11 , wherein the output torque is calculated based on the input torque and the refined disturbance torque.

14. The apparatus of claim 1 , wherein the input torque is determined using a feedback control loop.

15. The apparatus of claim 14 , wherein the feedback control loop is implemented using at least one proportional-derivative (PD) controller, the at least one PD controller comprising a PD controller configured to calculate an output angular velocity based on a difference between an instantaneous angle measured by the one or more sensors on the payload and the input angle.

16. The apparatus of claim 15 , wherein: the PD controller is a first PD controller; and the at least one PD controller further comprises a second PD controller configured to calculate the input torque based on a difference between an instantaneous angular velocity measured by the one or more sensors on the payload and the output angular velocity.

17. The apparatus of claim 1 , wherein the output torque is calculated by compensating the input torque with the estimated disturbance torque.

18. The apparatus of claim 17 , wherein the output torque is calculated by subtracting the estimated disturbance torque from the input torque.

19. The apparatus of claim 17 , wherein the output torque is used in conjunction with an actual disturbance torque to effect the movement of the carrier to achieve the desired attitude of the payload.

20. The apparatus of claim 19 , wherein the actual disturbance torque results from a disturbance to the carrier and is applied to the second frame.

Assignees

• Sz Dji Osmo Technology Co Ltd

Inventors

• Chen Zihan
• Pan Dahu
• Wang Jingyuan

Classifications

• B64U2201/20

  Remote controls · CPC title

• B64U2101/30

  for imaging, photography or videography · CPC title

• F16M11/2071

  for panning and rolling (F16M11/2078 takes precedence) · CPC title

• B64C17/00

  Aircraft stabilisation not otherwise provided for · CPC title

• F16M11/10

  around a horizontal axis {(F16M11/12 takes precedence)} · CPC title