Table of Contents

Executive Summary

Project Goal

The customer is developing a product to be worn on the human wrist and needs to understand the worst case shock & vibration conditions that product would endure to develop and qualify it. The project will:

  1. Gather shock and vibration data from 15 activities
  2. Analyze data into a series of power spectral densities and shock response spectrums per sport
  3. Futher summarize into 1 power spectral density test standard and 1 shock response spectrum test standard
    • Include for the shock data a representative half sine pulse that satifies the shock response spectrum

Acquiring Data

Data was acquired with enDAQ's S4-R500D40 which is small enough to be placed on the wrist as shown while also containing enough high powered sensors to give meaningful data. The device includes a 500g piezoresistive accelerometer which was sampled at 20,000 Hz. The device also captured rotation and orientation data but analysis of this was out of scope.

enDAQ Sensor Location on Wrist

Note the orientation of the axes in the image:

Data Summary

This table provides an overview of the maxium values seen in the tests using the resultant of all three axes. It also provides the total amount of data acquired for each sport.

Power Spectral Densities

Time History of Acceleration that Satisfies PSD Standard

Shock Response Spectrums

Half Sine Pulse to Test Product To

The SRS above can be fed into most shock systems, but below is a simple half sine pulse that will satisfy the SRS.

All Code

Getting the Data

Check Cloud API and Overview of Files

Table of Tags

Download Data Locally for Tags of Interest

Processing

Perform the Batch Processing

Summary of Data in Table

Plot the Metrics Data (Resultant Values)

Plot PVSS for All Sports

PVSS Max

SRS Max

Plot PSDs

PSD Max

Plot the Peak Shocks