Rotatable Middle Section Guided Projectile with Electromagnetic Regulator

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Solution Overview

Problem

Existing rotationally stabilized projectiles face limitations in gliding capability and guidability, especially at long firing ranges due to limited fin size and decreased rotation stability.

Innovation Solution

An actively rotatable middle section with extensible guide wings and a regulator device using electromagnetic principles, such as permanent magnets and electrical windings, to generate braking or variable rotational forces, allowing for improved guidance dynamics and positioning of the guide wings for enhanced aerodynamic surface and guidance control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the fin size is increased to improve gliding capability and guidance dynamic, then the guidance capability during gliding and end phase is improved, but the device complexity and structural constraints increase

Engineering Contradiction:
Improveguidance capabilityVSAvoidstructural constraints
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by making the middle section rotatable relative to the projectile body, allowing the guide fins to be actively positioned rather than fixed. This enables the fins to be extended to large sizes for improved gliding capability while maintaining structural flexibility. The rotatable middle section with guide fins can be actively positioned during flight to optimize guidance performance without being constrained by fixed structural arrangements.

Inventive Principle:
Principle #15Dynamics

2Stability of the object's composition

If a passive rotating middle section is used for roll stabilization, then rotational stability is achieved, but guidance precision decreases due to inability to actively control fin positioning

Engineering Contradiction:
Improverotational stabilityVSAvoidguidance precision
Core Design Contradiction:
Stability of the object's compositionVSMeasurement precision

Solution Approach 1:

The patent implements feedback control by using a regulator device that receives control signals and actively adjusts the rotational position of the middle section with guide fins. This feedback mechanism allows the system to maintain rotational stability while simultaneously controlling the fin positioning for precise guidance. The regulator device continuously monitors and adjusts the middle section's position to achieve both stability and guidance precision requirements.

Inventive Principle:
Principle #23Feedback

3Device complexity

If the fin size is limited due to structural constraints, then device complexity is reduced, but gliding capability and firing range are insufficient for long distances

Engineering Contradiction:
Improvestructural simplicityVSAvoidfiring range
Core Design Contradiction:
Device complexityVSLength of moving object

Solution Approach 1:

The patent overcomes the firing range limitation by implementing a rotatable middle section that can actively extend and position large guide fins during flight. This dynamic configuration allows the projectile to achieve the large fin size needed for long-distance gliding capability without being constrained by fixed structural arrangements. The fins can be extended when needed for gliding phase and repositioned according to guidance requirements.

Inventive Principle:
Principle #15Dynamics

4Device complexity

If fixed guide fins are used on a rotating middle section, then structural simplicity is maintained, but guidance dynamic is limited due to inability to actively adjust fin position

Engineering Contradiction:
Improvestructural simplicityVSAvoidguidance dynamic
Core Design Contradiction:
Device complexityVSPower

Solution Approach 1:

The patent resolves this contradiction by introducing a regulator device that provides active feedback control of the middle section's rotational position. While the basic structure remains relatively simple with fixed guide fins on the middle section, the feedback control system enables active adjustment of fin positioning during flight. This allows the system to maintain structural simplicity while achieving high guidance dynamic through controlled rotation of the middle section in response to control signals.

Inventive Principle:
Principle #23Feedback

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 solution enhances the guidance dynamic and gliding capability, increasing the total firing range and improving guidance precision during both the gliding and end phases of the projectile's trajectory.

Implementation Method 1

the regulator device is of the electromagnetic type comprising permanent magnets coaxially arranged on the inner side of the rotatable middle section concentrically around an electrical winding disposed on the intermediate projectile part, wherein the number and sizes of the permanent magnets are chosen such that a rotation of the middle section induces a magnetic field in the electrical winding, so that an electric current is generated in an electrical resistance connected to the electrical winding, which manifests itself as a braking force upon the rotating middle section

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the regulator device is of the electromagnetic type comprising permanent magnets coaxially arranged on the inner side of the rotatable middle section concentrically around an electrical winding disposed on the intermediate projectile part for the creation of variable rotational force on the middle section by virtue of the fact that the number and sizes of the permanent magnets are chosen for the creation of a static magnetic field oppositely directed to a variable magnetic field created by the electrical winding which has been variably energized from a separate electrical energy storage unit

Methodology Applied
Scientific EffectElectromagnetic interaction: Electromagnet

Data Source

PatentEP2729757B1Rotationally stabilized guidable projectile and method for guiding the same
Publication Date: 2017.11.15 BAE SYSTEM BOFORS AB
  • EP2729757B1 patent drawingFigure 1~4

AI summary

The invention relates to a rotationally stabilized projectile (1) for launching from a barrel, which projectile (1 ) comprises a front projectile part (22), a rear projectile part (20) comprising a rotating band (4), and an intermediate projectile part (21) comprising a freely rotatable middle section (2) arranged with guide wings (3) for improving the gliding capability and guidance capability during the gliding phase and end phase of the projectile. The guide wings (3) are arranged extensibly on the freely rotatable middle section (2), and the intermediate projectile part (21) also comprises a regulator device (14) for regulating the rotation of the middle section (2). The invention also relates to a method for guiding a rotationally stabilized projectile.