Table of contents

Mobile Robot Mapping - Lecture 2

Julian Ryde

Friday 20 April 2012

Sensor Modeling

Pieter Abbeel

Loop Closure more details


Pose graph relaxation

Grid based SLAM

Pieter Abbeel

RANdom SAmple Consensus, RANSAC

RANSAC pseudocode

while iterations < k
    maybe_inliers := n randomly selected values from data
    maybe_model := model parameters fitted to maybe_inliers
    consensus_set := maybe_inliers

    for every point in data not in maybe_inliers
        if point fits maybe_model with an error smaller than t
            add point to consensus_set

    if the number of elements in consensus_set is > d
        (this implies that we may have found a good model,
        now test how good it is)
        this_model := model parameters fitted to all points in consensus_set
        this_error := a measure of how well this_model fits these points
        if this_error < best_error
            (we have found a model which is better than any of the previous ones,
            keep it until a better one is found)
            best_model := this_model
            best_consensus_set := consensus_set
            best_error := this_error

    increment iterations

RANSAC Illustration