jumpSensorExample.m

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% =========================================================================== %
%> @example jumpSensorExample.m
%>
%> This example shows how to use the JumpSensor class to generate data from
%> the sensor. The example generates data for a sensor laying on a flat
%> surface, a sensor in free fall and a sensor in free fall with rotation.
%> The data is then plotted.
% =========================================================================== %
 
clc; clear; close all;
 
numsamples = 10000;
 
%% Create an instance of the JumpSensor class
js = JumpSensor();
 
%% first simple data: sensor laying on a flat surface
% the sensor is laying on a flat surface, so it is not accelerating nor
% rotating
 
% create ground truth data
acc = zeros(numsamples,3);
gyr = zeros(numsamples,3);
ori = quaternion.ones(numsamples,1);
%ori = quaternion(repmat([0,1,0,0], numsamples,1)); % z axis pointing upwards
%ori = quaternion(repmat([1/sqrt(2), 0, 1/sqrt(2), 0], numsamples,1)); % x axis pointing towards the sky
%ori = quaternion(repmat([1/sqrt(2), 1/sqrt(2), 0, 0], numsamples,1)); % y axis pointing downwards
 
% generate data
out1 = js.generate(acc, gyr, ori, simulate_hig=false);
 
% plot data
plotData(out1, 'Sensor laying on a flat surface');
 
%% second simple data: sensor in free fall
% the sensor is in free fall, so it is accelerating downwards, but not
% rotating (Assuming Vacuum)
 
% create ground truth data (NED frame)
acc = repmat([0, 0, 9.81], numsamples, 1);
gyr = zeros(numsamples,3);
ori = quaternion.ones(numsamples,1);
 
% generate data
out2 = js.generate(acc, gyr, ori);
 
% plot data
plotData(out2, 'Sensor in free fall');
 
% =========================================================================== %
%> @brief plots the data generated by the JumpSensor class
%>
%> @param data: struct with the data generated by the JumpSensor class
%> according to the format defined in @ref jumpReadData.m
%>
%> @param titName: title of the figure
%>
%> @retval none
% =========================================================================== %
function plotData(data, titName)
    figure('WindowState', 'maximized', 'Name', titName);
 
    % accelerometer
    subplot(221);
    plot(data.tt.t, data.tt.acc, data.tt.t, data.tt.hig);
    title("Accelerometer data");
    xlabel('Time');
    ylabel('Acceleration [m/s^2]');
    legend('x_{mpu}', 'y_{mpu}', 'z_{mpu}', 'x_{hig}', 'y_{hig}', 'z_{hig}');
    grid on;
 
    % gyroscope
    subplot(222);
    plot(data.tt.t, data.tt.gyr);
    title('Gyroscope data');
    xlabel('Time');
    ylabel('Angular velocity [°/s]');
    legend('x', 'y', 'z');
    grid on;
 
    % magnetometer
    subplot(223);
    plot(data.tt.t, data.tt.mag);
    title('Magnetometer data');
    xlabel('Time');
    ylabel('Magnetic field [uT]');
    legend('x', 'y', 'z');
    grid on;
 
    % pressure and temperature
    subplot(224);
    plot(data.tt.t, data.tt.prs);
    title('Pressure and temperature data');
    xlabel('Time');
    ylabel('Pressure [hPa]');
    yyaxis right;
    plot(data.tt.t, data.tt.tmp);
    ylabel('Temperature [°C]');
    legend('Pressure', 'Temperature');
    grid on;
end