Electrodynamic Modal Test Impactor System

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing modal analysis systems face challenges with manual impact excited methods due to variability in impact force and location, leading to inferior data quality and long test times, while automated systems are often too large, unwieldy, and lack control over impact characteristics, contaminating data and distorting the structure's response.

Innovation Solution

An automated electrodynamic modal test impactor system utilizing a compact design with a voice coil driven by an audio amplifier, integrated with a magnetic yoke and biasing device, allowing precise control over impact force and location, and supported by an articulating mounting device for flexible positioning, which minimizes data contamination and eliminates double impacts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual impact excited methods are used, then operator control over the hammer is possible, but impact force and location vary between impacts leading to inferior data quality

Engineering Contradiction:
Improveoperator controlVSAvoiddata quality
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces the manual mechanical hammer system with an automated electrodynamic impactor system. The electrodynamic impactor uses electromagnetic forces to generate controlled impacts, eliminating human variability in impact force and location. The system includes a voice coil actuator that precisely controls the impactor head position and impact characteristics, ensuring consistent and repeatable measurements.

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

Solution Approach 2:

The system incorporates self-aligning features where the impactor head automatically maintains proper orientation and positioning through mechanical guidance elements. The articulating mounting device allows the impactor to self-adjust to the test structure surface, reducing the need for manual intervention while maintaining precise impact control.

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If manual impact excited methods are used, then flexibility in testing is maintained, but test time increases due to time between impacts and double impacts

Engineering Contradiction:
Improvetesting flexibilityVSAvoidtest time
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The automated electrodynamic impactor system enables continuous impact sequencing without the delays inherent in manual operation. The system can execute rapid sequences of impacts at precisely controlled intervals, eliminating idle time between manual hammer swings and preventing accidental double impacts. The electrodynamic actuator can reset and fire repeatedly at high speed, maintaining continuous productive operation.

Inventive Principle:
Principle #20Continuity of useful action

3Extent of automation

If automated impact excited devices are used, then test automation is achieved, but device size becomes too large to fit in constrained spaces

Engineering Contradiction:
Improvetest automationVSAvoiddevice size
Core Design Contradiction:
Extent of automationVSVolume of moving object

Solution Approach 1:

The impactor assembly employs a nested structure where the articulating mounting device folds or telescopes to reduce overall size during transport and storage. The impactor head can be retracted into the body of the device, and the mounting arms collapse to minimize footprint, allowing the automated system to fit in constrained spaces while maintaining full functionality during operation.

Inventive Principle:
Principle #7Nested doll (Nesting)

4Extent of automation

If automated impact excited devices are used, then handling complexity increases making them unwieldy, but automation benefit is lost

Engineering Contradiction:
Improveautomation benefitVSAvoidhandling complexity
Core Design Contradiction:
Extent of automationVSEase of operation

Solution Approach 1:

The automated impactor system is divided into modular segments including a separate impactor head, articulating mounting device, and control system. This segmentation allows each component to be independently handled, positioned, and adjusted, reducing the complexity of manipulating the entire system as one unit. The modular design enables easy assembly, disassembly, and reconfiguration for different test scenarios.

Inventive Principle:
Principle #1Segmentation

5Force

If contact points are used between impact device and structure, then force transmission is direct, but data contamination occurs

Engineering Contradiction:
Improveforce transmissionVSAvoiddata contamination
Core Design Contradiction:
ForceVSMeasurement precision

Solution Approach 1:

The system uses a compliant impactor tip material that acts as an intermediary between the electrodynamic actuator and the test structure. This tip material transmits the impact force effectively while minimizing unwanted vibrations and noise from the impactor body itself. The tip can be selected from different materials and geometries to optimize force transmission while reducing data contamination from the impactor structure.

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 provides high-quality data with reduced test times, precise control over impact characteristics, and the ability to fit in constrained spaces, while maintaining structural integrity and avoiding data contamination, thus enhancing the accuracy and efficiency of modal analysis.

Implementation Method 1

A voice coil positioned in a magnetic gap of the magnetic yoke housing, the voice coil being driven by the audio amplifier

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

magnetic yoke housing (50), a magnet assembly (61) housed within the magnetic yoke housing (50)... a voice coil (112) positioned within the housing (22) in a magnetic gap (94) of the magnetic yoke housing (50)

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Data Source

PatentEP2738537B1Electrodynamic modal test impactor system and method
Publication Date: 2017.08.30 THE BOEING CO
  • EP2738537B1 patent drawingFigure 1A
  • EP2738537B1 patent drawingFigure 1B
  • EP2738537B1 patent drawingFigure 1C

AI summary

There is provided an electrodynamic modal test impactor system (10) and method. The system (10) has a controller device (12) and an impactor assembly (20) coupled to the controller device (12). The impactor assembly (20) has a housing (22) and a permanent magnet (70) positioned within the housing (22). The impactor assembly (20) further has a voice coil (112) positioned within the housing (22) in a magnetic gap (94) of a magnetic yoke housing (50). The voice coil (112) is driven by the controller device (12). The impactor assembly (20) further has a drive shaft (130) supported by two or more support elements (174). The drive shaft (130) is attached to the voice coil (112) and is driven by the voice coil (112). The impactor assembly (20) further has a load cell (144) attached to a free end (142) of the drive shaft (130) and a biasing device (96) positioned within the magnetic yoke housing (50).