High-speed omnidirectional underwater propulsion mechanism

Patent metadata

Field	Value
Publication number	US-2022388617-A1
Application number	US-202117531007-A
Country	US
Kind code	A1
Filing date	Nov 19, 2021
Priority date	Nov 20, 2020
Publication date	Dec 8, 2022
Grant date	—

Abstract

Various examples of a high-speed omnidirectional fully-actuated underwater propulsion mechanism are described. In one example, a propulsion system includes two decoupled counter-rotating rotors centered on a main axis, with each rotor comprising a plurality of pivotable blades projecting radially from the main axis, a servo-swashplate actuation mechanism comprising a plurality of servos and a linkage assembly connected from the servos to the pivotable blades, a blade-axis re-enforcing flap adapter comprising a plurality of stationary flaps, with the blade-axis re-enforcing flap adapter being positioned in a region between the two decoupled counter-rotating rotors centered on the main axis, and a controller. The controller can be configured to calculate control parameters, compensate a first control parameter among the control parameters to reduce cross-coupling of an unwanted force generated by drag forces on the two decoupled counter-rotating rotors, and generate a control signal for each of the servos based on the control parameters.

First claim

Therefore, the following is claimed:

1 . A propulsion system, comprising:
two decoupled counter-rotating rotors centered on a main axis, each rotor comprising a plurality of pivotable blades projecting radially; a blade-axis re-enforcing flap adapter comprising a plurality of stationary flaps, the blade-axis re-enforcing flap adapter being positioned in a region between the two decoupled counter-rotating rotors centered on the main axis; two servo-swashplate actuation mechanisms positioned on opposing ends of the two decoupled counter-rotating rotors along the main axis, each servo-swashplate actuation mechanism comprising a plurality of servos and a linkage assembly connected from the servos to the pivotable blades; and a controller configured to:
calculate a plurality of control parameters;
compensate a first control parameter among the control parameters; and
generate a control signal for each of the servos based on the control parameters.

2 . The propulsion system of claim 1 , wherein the plurality of control parameters comprise a surge control parameter α, a yaw control parameter β, a sway control parameter Γ, and a roll control parameter δ.

3 . The propulsion system of claim 1 , wherein the controller is configured to compensate the first control parameter to reduce cross-coupling of an unwanted force generated by drag forces on the two decoupled counter-rotating rotors.

4 . The propulsion system of claim 1 , wherein the controller is configured to compensate the first control parameter to reduce cross-coupling of an unwanted force due to a second control parameter.

5 . The propulsion system of claim 4 , wherein:
the first control parameter comprises a sway control parameter Γ; the second control parameter comprises a surge control parameter α; and the controller is configured to compensate the sway control parameter Γ to reduce cross-coupling of an unwanted force due to the surge control parameter α.

6 . The propulsion system of claim 1 , wherein the controller is configured to compensate the first control parameter to reduce cross-coupling of an unwanted force based on a ratio of the unwanted force to a desired force.

7 . The propulsion system of claim 1 , wherein the controller is configured to compensate the first control parameter to reduce cross-coupling of an unwanted force based on a system of equations linking two planes controlled by the servos.

8 . The propulsion system of claim 1 , wherein the blade-axis re-enforcing flap adapter comprises eight stationary flaps.

9 . The propulsion system of claim 8 , wherein the eight stationary flaps of the blade-axis re-enforcing flap adapter reduce flow leakage between high and low pressure regions in the region between the two decoupled counter-rotating rotors.

10 . The propulsion system of claim 1 , wherein the blade-axis re-enforcing flap adapter comprises more than eight stationary flaps.

11 . The propulsion system of claim 1 , wherein the stationary flaps of the blade-axis re-enforcing flap adapter reduce unwanted flow during a sway maneuver of the propulsion system.

12 . The propulsion system of claim 1 , wherein each servo among the plurality of servos controls a pitch of the pivotable blades passing through a particular quadrant.

13 . A method of controlling a propulsion system, the propulsion system comprising:
two decoupled counter-rotating rotors centered on a main axis, each rotor comprising a plurality of pivotable blades projecting radially from the main axis; a servo-swashplate actuation mechanism comprising a plurality of servos and a linkage assembly connected from the servos to the pivotable blades; a blade-axis re-enforcing flap adapter comprising a plurality of stationary flaps, the blade-axis re-enforcing flap adapter being positioned in a region between the two decoupled counter-rotating rotors centered on the main axis; and a controller, wherein the method comprises:
calculating, by the controller, a plurality of control parameters;
compensating, by the controller, a first control parameter among the control parameters; and
generating, by the controller, a control signal for each of the servos based on the control parameters.

14 . The method of claim 13 , wherein the plurality of control parameters comprise a surge control parameter α, a yaw control parameter β, a sway control parameter Γ, and a roll control parameter δ.

15 . The method of claim 13 , further comprising compensating, by the controller, the first control parameter to reduce cross-coupling of an unwanted force generated by drag forces on the two decoupled counter-rotating rotors.

16 . The method of claim 13 , further comprising compensating, by the controller, the first control parameter to reduce cross-coupling of an unwanted force due to a second control parameter.

17 . The method of claim 16 , wherein:
the first control parameter comprises a sway control parameter Γ; the second control parameter comprises a surge control parameter α; and the method further comprises compensating, by the controller, the sway control parameter Γ to reduce cross-coupling of an unwanted force due to the surge control parameter α.

18 . The method of claim 13 , further comprising compensating, by the controller, the first control parameter to reduce cross-coupling of an unwanted force based on a ratio of the unwanted force to a desired force.

19 . The method of claim 13 , further comprising compensating, by the controller, the first control parameter to reduce cross-coupling of an unwanted force based on a system of equations linking two planes controlled by the servos.

20 . The method of claim 13 , wherein:
the blade-axis re-enforcing flap adapter comprises eight stationary flaps; and the eight stationary flaps reduce unwanted flow during a sway maneuver of the propulsion system.

Assignees

• Virginia Tech Intellectual Properties Inc

Inventors

• Njaka Taylor
• Ben-Tzvi Pinhas
• Brizzolara Stefano

Classifications

• B63G2008/002

  unmanned · CPC title

• B63H1/26 Primary

  Blades · CPC title

• B63B39/00

  Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude {(for amphibious vehicles B60F3/0038)} · CPC title

• B63H2021/216

  using electric control means · CPC title

• B63H21/21

  Control means for engine or transmission, specially adapted for use on marine vessels · CPC title