node-pedometer

Pedometer implementation for node.js

Build status


Notes

Uses a windowed average peak counting algorithm to perform low-cost step detection.

Assumes all input data to be 2D arrays

[[x1, y1, z1], [x2, y2, z2],...]
[[pitch1, roll1, yaw1]. [pitch2, roll2, yaw2],... ] (in Radians)

Installation

npm install pedometer --save

Usage

var pedometer = require('pedometer').pedometer;
var steps=pedometer(accelerometerData,attitudeData,samplingrate,options);

accelerometerdata is a time series of 3D acceleration vectors in m/s^2
[[x1, y1, z1], [x2, y2, z2],...]

attitudeData is a time series of 3D attitude vectors in radians
[[pitch1, roll1, yaw1]. [pitch2, roll2, yaw2],... ]

samplingrate is the number of samples per second. All tests were done with 100Hz

options provides optional parameters. Default values are:

options={
windowSize:1, //Length of window in seconds
minPeak:2, //minimum magnitude of a steps largest positive peak
maxPeak:8, //maximum magnitude of a steps largest positive peak
minStepTime: 0.3, //minimum time in seconds between two steps
peakThreshold: 0.5, //minimum ratio of the current window's maximum to be considered a step
minConsecutiveSteps: 3, //minimum number of consecutive steps to be counted
maxStepTime: 0.8, //maximum time between two steps to be considered consecutive
meanFilterSize: 1, //Amount of smoothing (Values <=1 disable the smoothing)
debug:false //Enable output of debugging data in matlab/octave format
}

Returns an array of the indices in the input signal where steps occured

See src/debug.js and test/test.js for more examples

Example

Before you run this, make sure to have installed the modules fs and csv-parse.

var pedometer = require('pedometer').pedometer,
fs = require('fs'),
parse = require('csv-parse/lib/sync');

//Function to load Data from csv file
function loadData(filename){

//Load file
var data=fs.readFileSync(filename,'utf8');

//parse CSV
data=parse(data, {trim: true, auto_parse: true});

//Store data in arrays
var acc=[],att=[];
for (var i=0;i acc[i]=data[i].slice(0,3);
att[i]=[data[i][4], -data[i][5],data[i][3]]; //Attitude is adjusted to correctly match [ pitch, roll, yaw ]
}

//Return arrays
return {acc:acc,att:att};
}

//Load first test case
var data=loadData('node_modules/pedometer/test/DataWalking1.csv'); //You might need to adjust the path here

//Define algorithm options (optional). All recommended default values here.
var options={
windowSize:1, //Length of window in seconds
minPeak:2, //minimum magnitude of a steps largest positive peak
maxPeak:8, //maximum magnitude of a steps largest positive peak
minStepTime: 0.3, //minimum time in seconds between two steps
peakThreshold: 0.5, //minimum ratio of the current window's maximum to be considered a step
minConsecutiveSteps: 3, //minimum number of consecutive steps to be counted
maxStepTime: 0.8, //maximum time between two steps to be considered consecutive
meanFilterSize: 1, //Amount of smoothing (Values <=1 disable the smoothing)
debug:false //Enable output of debugging data in matlab/octave format
};

//Perform step detection. Leaving away ,options here (recommended), will use the default settings as specified above.
var steps=pedometer(data.acc,data.att,100,options);

//Print number of detected steps
console.log("The algorithm detected "+steps.length+" steps.");

Output:

The algorithm detected 116 steps.

Test

npm test

Returns:

Detect steps in acceleration signal
The algorithm detected 116 steps.
✓ Test 1 - Signal of walk 1 (186ms)
The algorithm detected 292 steps.
✓ Test 2 - Signal of walk 2 (442ms)
The algorithm detected 25 steps.
✓ Test 3 - Signal of walk 3 (54ms)
The algorithm detected 27 steps.
✓ Test 4 - Signal of walk 4 (47ms)
The algorithm detected 483 steps.
✓ Test 5 - Signal of walk 5 (732ms)
The algorithm detected 16 steps.
✓ Test 6 - Signal of not walking 1 (558ms)
The algorithm detected 10 steps.
✓ Test 7 - Signal of not walking 2 (130ms)
The algorithm detected 28 steps.
✓ Test 8 - Signal of not walking 3 (787ms)
The algorithm detected 0 steps.
✓ Test 9 - Signal of not walking 4 (891ms)
The algorithm detected 23 steps.
✓ Test 10 - Signal of not walking 5 (235ms)
The algorithm detected 68 steps.
✓ Test 11 - Signal of mixed action 1 (751ms)
The algorithm detected 46 steps.
✓ Test 12 - Signal of mixed action 2 (792ms)


12 passing (6s)

License

MIT License

Copyright (c) 2016 Maximilian Bügler

Permission is hereby granted, free of charge, to any person obtaining a copy
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in the Software without restriction, including without limitation the rights
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The above copyright notice and this permission notice shall be included in all
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