Projectile Position Detection via Structure-Borne Sound Triggered Flash

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Solution Overview

Problem

Existing methods for detecting the position of a projectile on a target, such as using sound sensors, suffer from low accuracy due to the high speed of sound propagation in solid bodies, leading to imprecise determination of the impact point.

Innovation Solution

A target device equipped with an optical display and a structure-borne noise pickup that emits a brief flash of light when a projectile hits the pane, allowing a camera to capture the projectile's position accurately, even with a camera of limited frame rate, by synchronizing the light source with the impact using a structure-borne noise sensor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If sound sensors are used to detect projectile position based on sound propagation in solid bodies, then the detection system is simple and cost-effective, but the measurement precision is low due to the very high speed of sound propagation in solids resulting in small time-of-flight differences

Engineering Contradiction:
Improvedetection system simplicity and cost-effectivenessVSAvoidprojectile position determination accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent introduces an intermediary substance (gas or liquid) between the projectile impact point and the sound sensor. This intermediary has a lower sound propagation speed than solid bodies, which amplifies the time-of-flight difference and enables more precise position determination while keeping the detection system relatively simple

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the direct solid-body sound transmission mechanism with an alternative mechanism using gas or liquid as the sound propagation medium. This substitution changes the physical properties of sound transmission, resulting in slower propagation speed and larger measurable time differences for position calculation

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If conventional cameras with limited frame rate are used to capture projectile position, then the device complexity and cost are reduced, but the measurement precision is insufficient due to the inability to capture fast-moving projectiles accurately

Engineering Contradiction:
Improvecamera system complexity and costVSAvoidprojectile position detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent triggers the camera to capture images only at the precise moment when the projectile impacts the target, rather than requiring continuous high-speed recording. This preliminary timing action allows conventional cameras with limited frame rates to capture the critical position data accurately without needing expensive high-speed camera systems

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses periodic triggering based on the impact event to activate the camera at the exact moment of projectile arrival. This event-driven periodic action synchronizes the camera capture with the projectile impact, enabling accurate position measurement using standard camera equipment

Inventive Principle:
Principle #19Periodic action

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 configuration achieves high accuracy in projectile position detection while being cost-effective, using conventional cameras and reducing the need for expensive high-speed cameras, and allows for precise recording of the projectile's position at the moment of impact.

Implementation Method 1

at least one vibration sensor of this type arranged on the target pane in the direction of firing

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

A light source for emitting a flash... the light source emits the flash depending on an output signal from at least one vibration sensor

Methodology Applied
Scientific EffectLight emission: Light

Implementation Method 3

a camera for detecting the projectile's position... the camera to capture the projectile's position accurately

Methodology Applied
Scientific EffectOptical detection: Photography

Implementation Method 4

evaluating sound waves using transducers and calculating the position based on the time-of-flight difference does not achieve high accuracy because the speed of sound propagation in solids is very high

Methodology Applied
Scientific EffectStructure-borne sound propagation: Sound

Data Source

PatentEP3644008B1Targeting device and method for detecting the position of a projectile
Publication Date: 2023.03.01 KE KNESTEL ELEKTRONIK GMBH
  • EP3644008B1 patent drawingFigure 1
  • EP3644008B1 patent drawingFigure 2
  • EP3644008B1 patent drawingFigure 3

AI summary

The present invention relates to a targeting device and a method for detecting a projectile position, wherein a short flash of light is triggered by detecting an impact shock wave through the use of structure-borne sound sensors, so that a projectile position can be detected via a camera.