Rotorcraft control laws for sea-based operations

Patent metadata

Field	Value
Publication number	US-9429952-B2
Application number	US-201414245036-A
Country	US
Kind code	B2
Filing date	Apr 4, 2014
Priority date	Apr 4, 2014
Publication date	Aug 30, 2016
Grant date	Aug 30, 2016

Abstract

A method and system of controlling a rotorcraft for sea-based operations includes receiving sensed information indicative of an operation of the rotorcraft; receiving operator commands, ship models and system constraints; and determining a solution to an optimization function that avoids violating the system constraints, the solution being representative of control command signals for augmenting a flight response of the rotorcraft to a ship.

First claim

What is claimed is:

1. A method of controlling a rotorcraft for sea-based operations, comprising:
receiving, with a processor, sensed information indicative of an operation of the rotorcraft;
receiving, with the processor, operator commands, ship models and system constraints including relative velocity limits between the ship and the rotorcraft, accuracy of a landing position on the ship, landing gear structural integrity, sink rate of the rotorcraft, and impact velocity of the rotorcraft on the ship;
determining, with a model predictive control (MPC) prediction module that employs a model based feedforward control utilizing a prediction algorithm, a solution to an optimization function that avoids violating the system constraints, the solution being representative of control command signals for augmenting a flight response of the rotorcraft to a ship;
determining, with the processor, a solution to continuously update the system constraints that optimize a cost function utilizing MPC theory; and
commanding the displacement of servos and linkages for controlling said rotorcraft.

2. The method of claim 1 , wherein the optimization function includes mathematical terms for command tracking errors and control of an actuator that is associated with the rotorcraft.

3. The method of claim 1 , wherein the receiving of the sensed information further comprises receiving at least one of angular rate, attitude response, and acceleration rate for the rotorcraft.

4. The method of claim 1 , further comprising determining at least one of a relative position and motion between the ship and the rotorcraft.

5. The method of claim 1 , wherein the ship models further comprises a ship airwake model and a ship motion model.

6. The method of claim 5 , wherein the ship airwake model comprises a model of an air flow field surrounding the ship.

7. The method of claim 5 , wherein the ship motion model comprises a model of a response of the ship advancing at constant forward speed.

8. A control system of a rotorcraft during sea-based operations, comprising:
rotors, each rotor comprising a plurality of blades;
a processor; and
memory having instructions stored thereon that, when executed by the processor, cause the system to:
receive, with the processor, sensed information indicative of an operation of the rotorcraft;
receive, with the processor, operator commands, ship models and system constraints including relative velocity limits between the ship and the rotorcraft, accuracy of a landing position on the ship, landing gear structural integrity, sink rate of the rotorcraft, and impact velocity of the rotorcraft on the ship;
determine, with a model predictive control (MPC) prediction module that employs a model based feedforward control utilizing a prediction algorithm, a solution to an optimization function that avoids violating the system constraints, the solution being representative of control command signals for controlling the rotors of the rotorcraft approaching a ship;
determine, with the processor, a solution to continuously update the system constraints that optimize a cost function utilizing MPC theory; and
command the displacement of servos and linkages for controlling said rotorcraft.

9. The control system of claim 8 , wherein the optimization function includes mathematical terms for command tracking errors and control of at least one actuator that is associated with the rotors.

10. The control system of claim 8 , wherein the processor is configured to receive at least one of angular rate, attitude response, and acceleration rate for the rotorcraft.

11. The control system of claim 8 , wherein the processor is configured to determine at least one of a relative position and motion between the ship and the rotorcraft.

12. The control system of claim 8 , wherein the ship models further comprises a ship airwake model and a ship motion model.

13. The control system of claim 12 , wherein the ship airwake model comprises a model of an air flow field surrounding the ship.

14. The control system of claim 12 , wherein the ship motion model comprises a model of a response of the ship advancing at constant forward speed.

Assignees

• Sikorsky Aircraft Corp

Inventors

• Geiger Derek
• Rigsby James
• Greenfield Aaron L
• Sahasrabudhe Vineet
• Goss Jennifer D

Classifications

• G05D1/0684 Primary

  on a moving platform, e.g. aircraft carrier · CPC title

• G05D1/0676 Primary

  specially adapted for landing · CPC title

• B64C27/00

  Rotorcraft; Rotors peculiar thereto · CPC title

• G05B13/04

  involving the use of models or simulators · CPC title

• G05D1/00

  Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots (drive control systems specially adapted for autonomous road vehicles B60W60/00) · CPC title