Detachable Grid Fin Missile Control System

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Solution Overview

Problem

Existing missile control systems face challenges in achieving low-speed guidance control and stability during launch, particularly when intercepting low-altitude threats, due to the limitations of traditional control surfaces and thrust vector control systems, which are often heavy, costly, and inefficient at low speeds.

Innovation Solution

A detachable aerodynamic missile control system featuring a grid fin interstage assembly with movable grid fins that provide increased drag and lift, coupled to the aft portion of the missile, and an articulation control system to control the orientation of the grid fins, allowing for rapid pitch-over and stability during low-speed flight, while being lightweight and compatible with existing missile designs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If control surfaces are sized for high speed use, then high speed control authority is improved, but low speed effectiveness deteriorates

Engineering Contradiction:
Improvehigh speed control authorityVSAvoidlow speed effectiveness
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The control surfaces are designed to be movable and adjustable in size. At high speeds, the control surfaces are extended to provide sufficient control authority. At low speeds, the control surfaces are retracted or reduced in size to maintain effectiveness without excessive weight and drag. This dynamic adjustment resolves the contradiction between high speed control authority and low speed effectiveness.

Inventive Principle:
Principle #15Dynamics

2Reliability

If control surfaces are sized for low speed use, then low speed effectiveness is improved, but device weight increases

Engineering Contradiction:
Improvelow speed effectivenessVSAvoidcontrol surface weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The control surfaces are designed to be movable and adjustable in size. At low speeds, the control surfaces are extended to provide sufficient control authority. At high speeds, the control surfaces are retracted or reduced in size to minimize weight and drag. This dynamic adjustment resolves the contradiction between low speed effectiveness and device weight.

Inventive Principle:
Principle #15Dynamics

3Reliability

If movable nozzle systems are used for thrust vector control, then low speed guidance control is improved, but device complexity and weight increase

Engineering Contradiction:
Improvelow speed guidance controlVSAvoidnozzle system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the thrust vector control function from the main engine nozzle and implements it through a separate, simpler movable nozzle system that can be independently controlled. This extracted subsystem provides low speed guidance control without the complexity of integrating movable mechanisms into the main propulsion system, resolving the contradiction between low speed guidance control and device complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

4Stability of the object's composition

If jet vanes are placed in the missile exhaust flow, then low speed stability is improved, but missile motor performance deteriorates

Engineering Contradiction:
Improvelow speed stabilityVSAvoidmissile motor performance
Core Design Contradiction:
Stability of the object's compositionVSUse of energy by moving object

Solution Approach 1:

The invention introduces an intermediary flow path that allows the jet vanes to be positioned in the exhaust flow for stability control while maintaining a separate clean flow path for the majority of the propellant. This intermediary arrangement enables the jet vanes to provide low speed stability without significantly interfering with the main propellant flow and motor performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system enables rapid pitch-over and enhanced stability at low speeds, reducing the risk of overshooting targets and optimizing intercept trajectories, without the need for costly modifications to existing missile systems, and can be easily retrofitted to various missile types.

Implementation Method 1

the grid fins providing increased drag and lift to allow pitch-over when deployed

Methodology Applied
Scientific EffectDrag: Drag

Implementation Method 2

the grid fins providing increased drag and lift to allow pitch-over when deployed

Methodology Applied
Scientific EffectLift: Aerofoil

Implementation Method 3

an articulation control system configured to control an orientation of the grid fins and to link with a control system of the missile

Methodology Applied
Scientific EffectAerodynamic control: Aerofoil

Data Source

PatentEP2100089B1Detachable aerodynamic missile control system
Publication Date: 2015.07.29 RAYTHEON CO
  • EP2100089B1 patent drawingFigure 1
  • EP2100089B1 patent drawingFigure 2
  • EP2100089B1 patent drawingFigure 3

AI summary

Provided is a detachable aerodynamic missile stabilizing system (130) for a missile (100) flying at low flight speeds. The system (130) includes a housing (134) adapted to couple to the missile (100). Extending outward from the housing (134) is at least one grid fin (136). Specifically the grid fin (136) extends from the housing (134) such that it is transverse to a longitudinal axis (110) of the housing (134) and the missile (100). The grid fin (136) provides a plurality of apertures (144). The apertures (144) are parallel to the longitudinal axis (110) of the housing (134) and the missile (100). A coupler (138) is adapted to detachably couple the housing (134) to the missile (100). A method of use is also provided.