Magnetic field data for SLAM

This repository contains magnetic field (MF) data collected in 2010-2011 with iRobot Create and MicroMag 3-axis magnetometer to perform MF-based SLAM. The data is used in experiments in my PhD research and the related MF SLAM papers (e.g. here, here, and here), and published for reproducibility.

SLAM trajectories	Corresponding magnetometer readings	Validation data (loop closures)

Contents

Processed csv files data/processed_csv

• Original data converted to csv format easily readable by modern tools, such as Pandas.
  • Conversion script in notebooks/process_raw_data.ipynb
• Named columns and only relevant fields left:
  • t - relative (zero-based) time in seconds
  • x, y - spatial coordinates in meters
  • theta - heading in radians
  • mx, my, mz - magnetometer readings in uT
  • spacebar - manual keyboard press (for validation data)
• Different MF scaling factors corrected from the original data
• Only minor median filtering performed to remove MF outliers
• Should be easy to downsample as needed using Pandas, for example

Original txt files data/original_txt

• Raw mapping data (used to produce SLAM data by downsampling and filtering)
• Validation data (used to evaluate localization performance afterwards)
• Calibration data (used to find out the magnetometer bias)

Original downsampled data/original_downsampled

• Matlab script to visualize the raw data and produce SLAM data
• Downsampled 2Hz data for selected data sets (contains produced robot control and MF readings)

Format for original data fields

Column numbering starting from 1 (for included MATLAB script).

Raw mapping and validation data (original format)

• Odometry x and y, mm (1-2)
• Odometry heading, angles (4)
• Odometry distance, mm (5)
• Magnetometer data, uT scaled by 32 (or 8), and y and z multiplied by -1 (6-8)
• Space bar press indicator (18)
• Time stamp (19)

Processed 2Hz SLAM control data (updated to CSV)

• Forward translation, m (1)
• Heading change, radians (2)
• Magnetic data, uT (3-5)
• Time stamp, s (6)