177 lines
4.0 KiB
C++
177 lines
4.0 KiB
C++
#ifndef STEPDETECTION3_H
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#define STEPDETECTION3_H
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#include "AccelerometerData.h"
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#include "../../data/Timestamp.h"
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#include <cmath>
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#include <vector>
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#ifdef WITH_DEBUG_PLOT
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#include <KLib/misc/gnuplot/Gnuplot.h>
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#include <KLib/misc/gnuplot/GnuplotSplot.h>
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#include <KLib/misc/gnuplot/GnuplotSplotElementLines.h>
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#include <KLib/misc/gnuplot/GnuplotPlot.h>
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#include <KLib/misc/gnuplot/GnuplotPlotElementLines.h>
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#include <KLib/misc/gnuplot/GnuplotPlotElementPoints.h>
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#endif
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#ifdef WITH_DEBUG_OUTPUT
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#include <fstream>
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#endif
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#include "../../Assertions.h"
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#include "../../math/dsp/iir/BiQuad.h"
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#include "../../math/FixedFrequencyInterpolator.h"
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#include "../../math/DelayBuffer.h"
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/**
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* simple step detection based on accelerometer magnitude.
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* magnitude > threshold? -> step!
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* block for several msec until detecting the next one
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*/
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class StepDetection3 {
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static constexpr float gravity = 9.81;
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static constexpr float stepRate_hz = 2.0;
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static constexpr int sRate_hz = 100;
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static constexpr int every_ms = 1000 / sRate_hz;
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static constexpr float threshold = 1.0;
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float max = 0;
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Timestamp maxTS;
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private:
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FixedFrequencyInterpolator<AccelerometerData> interpol;
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IIR::BiQuad<float> biquad;
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DelayBuffer<float> delay;
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#ifdef WITH_DEBUG_PLOT
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K::Gnuplot gp;
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K::GnuplotPlot plot;
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K::GnuplotPlotElementLines lineRaw;
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K::GnuplotPlotElementLines lineFiltered;
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K::GnuplotPlotElementPoints pointDet;
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Timestamp plotRef;
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Timestamp lastPlot;
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#endif
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#ifdef WITH_DEBUG_OUTPUT
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std::ofstream outFiltered;
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std::ofstream outSteps;
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#endif
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public:
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/** ctor */
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StepDetection3() : interpol(Timestamp::fromMS(every_ms)), delay(10) {
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biquad.setBandPass(stepRate_hz, 1.0, sRate_hz);
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biquad.preFill(gravity);
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#ifdef WITH_DEBUG_PLOT
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gp << "set autoscale xfix\n";
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plot.setTitle("Step Detection");
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plot.add(&lineRaw); lineRaw.getStroke().getColor().setHexStr("#0000FF");
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plot.add(&lineFiltered); lineFiltered.getStroke().getColor().setHexStr("#000000");
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plot.add(&pointDet); pointDet.setPointSize(2); pointDet.setPointType(7);
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#endif
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#ifdef WITH_DEBUG_OUTPUT
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outFiltered = std::ofstream("/tmp/sd2_filtered.dat");
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outSteps = std::ofstream("/tmp/sd2_steps.dat");
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#endif
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}
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/** does the given data indicate a step? */
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bool add(const Timestamp ts, const AccelerometerData& acc) {
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bool gotStep = false;
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// accel-data incoming on a fixed sampling rate (needed for FIR to work)
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// NOTE!!!! MIGHT TRIGGER MORE THAN ONCE PER add() !!!
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auto onResample = [&] (const Timestamp ts, const AccelerometerData data) {
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bool step = false;
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const float mag = data.magnitude();
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// apply filter
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const float fMag = biquad.filter(mag);
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// history buffer
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float fMagOld = delay.add(fMag);
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// zero crossing?
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float tmp = max;
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if (fMagOld > 0 && fMag < 0) {
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if (max > threshold) {
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step = true;
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gotStep = true;
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}
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delay.setAll(0);
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max = 0;
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}
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// track maximum value
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if (fMag > max) {max = fMag; maxTS = ts;}
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#ifdef WITH_DEBUG_OUTPUT
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if (step) {
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std::cout << ts.ms() << std::endl;
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outSteps << maxTS.ms() << " " << tmp << "\n";
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outSteps.flush();
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}
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outFiltered << ts.ms() << " " << fMag << "\n";
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#endif
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#ifdef WITH_DEBUG_PLOT
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if (plotRef.isZero()) {plotRef = ts;}
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const Timestamp tsPlot = (ts-plotRef);
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const Timestamp tsOldest = tsPlot - Timestamp::fromMS(5000);
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lineRaw.add( K::GnuplotPoint2(tsPlot.ms(), mag) );
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lineFiltered.add( K::GnuplotPoint2(tsPlot.ms(), fMag) );
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if (step) {
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pointDet.add( K::GnuplotPoint2((maxTS-plotRef).ms(), tmp) );
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}
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if (lastPlot + Timestamp::fromMS(50) < tsPlot) {
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lastPlot = tsPlot;
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auto remove = [tsOldest] (const K::GnuplotPoint2 pt) {return pt.x < tsOldest.ms();};
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lineRaw.removeIf(remove);
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lineFiltered.removeIf(remove);
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pointDet.removeIf(remove);
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gp.draw(plot);
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gp.flush();
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usleep(100);
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}
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#endif
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};
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// ensure fixed sampling rate for FIR freq filters to work!
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interpol.add(ts, acc, onResample);
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return gotStep;
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}
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};
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#endif // STEPDETECTION3_H
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