Spin-Stabilized Projectile Steering Using ML and Asymmetric Surfaces

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Solution Overview

Problem

Conventional guided projectiles face challenges in reducing the spatial volume and mass of guidance and control hardware to increase propellant, charge, and sensor volumes, thereby affecting the endurance, range, and accuracy of small calibre projectiles, particularly in steering without protruding external fins.

Innovation Solution

A computer-implemented method using a machine learning algorithm, specifically reinforcement learning, to control spin-stabilized steerable projectiles by training the algorithm with data from simulated or measured trajectories, allowing the projectile to adjust its trajectory through angular rotation of an asymmetric surface, thereby eliminating the need for external fins.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If protruding external control surfaces are used for steering, then steering capability is improved, but spatial volume and mass of control hardware increases

Engineering Contradiction:
Improvesteering capabilityVSAvoidspatial volume of control hardware
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The invention extracts the control function from external protruding surfaces and relocates it to internal asymmetric mass distribution. The asymmetric mass element is positioned off-center within the projectile body, eliminating the need for external fins or control surfaces while maintaining steering capability through aerodynamic moment generation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The control mechanism is nested within the projectile body. The asymmetric mass element is contained inside the projectile shell, with the mass distribution arranged such that the center of mass does not coincide with the geometric center, creating the necessary aerodynamic imbalance for steering without requiring external components.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of operation

If protruding external control surfaces are used for steering, then steering capability is improved, but mass of control hardware increases

Engineering Contradiction:
Improvesteering capabilityVSAvoidmass of control hardware
Core Design Contradiction:
Ease of operationVSWeight of moving object

Solution Approach 1:

The invention extracts the control function from external protruding surfaces and relocates it to internal asymmetric mass distribution. The asymmetric mass element is positioned off-center within the projectile body, eliminating the need for external fins or control surfaces while maintaining steering capability through aerodynamic moment generation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The projectile employs composite construction with asymmetric mass distribution achieved through strategic placement of denser materials or voids within the projectile body. This allows mass redistribution for control purposes without adding overall projectile mass, as the control mechanism utilizes the existing structural materials in an asymmetric configuration.

Inventive Principle:
Principle #40Composite materials

3Ease of operation

If internal volume is allocated for control hardware, then steering capability is improved, but volume for propellant and explosives decreases

Engineering Contradiction:
Improvesteering capabilityVSAvoidvolume for propellant and explosives
Core Design Contradiction:
Ease of operationVSQuantity of substance

Solution Approach 1:

The invention extracts the control function from external protruding surfaces and relocates it to internal asymmetric mass distribution. The asymmetric mass element is positioned off-center within the projectile body, eliminating the need for external fins or control surfaces while maintaining steering capability through aerodynamic moment generation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The projectile body structure serves multiple functions: it contains the propellant and explosive charges while simultaneously providing the asymmetric mass distribution necessary for steering. The same structural materials that form the projectile shell also create the control moment through their asymmetric arrangement, eliminating the need for separate dedicated control hardware volume.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

This approach enhances the accuracy and precision of projectile steering by optimizing the use of internal space for propellant and sensors, improving the range and lethality of small calibre projectiles while reducing the reliance on external control surfaces.

Implementation Method 1

the asymmetric surface exerts an imbalance upon the projectile to control the trajectory of said projectile

Methodology Applied
Scientific EffectAerodynamic force: Drag

Implementation Method 2

Spin-stabilized steerable projectiles

Methodology Applied
Scientific EffectSpin stabilization: Centrifugal Force

Data Source

PatentUS20240280352A1Spin-stabilized steerable projectile control
Publication Date: 2024.08.22 BAE SYSTEMS PLC
  • US20240280352A1 patent drawing
  • US20240280352A1 patent drawing
  • US20240280352A1 patent drawing

AI summary

A computer-implemented method of training a machine learning, ML algorithm to control spin-stabilized steerable projectiles is described. The method comprises: obtaining training data including respective policies and corresponding trajectories of a set of spin-stabilized steerable projectiles including a first projectile, wherein each policy relates to steering a projectile of the set thereof towards a target and wherein each corresponding trajectory comprises a series of states in a state space of the projectile (S2001); and training the ML algorithm comprising determining relationships between the respective policies and corresponding trajectories of the projectiles of the set thereof based on respective results of comparing the trajectories and the targets (S2002).