FixTheRobot Explore Robotics / Localization & SLAM / M8 / M8-L1

This lab works on phones, but writing code is much easier on a laptop.

Localization & SLAM · Advanced SLAM and Research · M8-L1 · Intermediate

Handle Dynamic Objects in Mapping

The map of the corridor is ready, and it has a diagonal smear across the middle where the cleaning staff walked, and a small blob where someone waited for the lift. A planner using this map would refuse to go through either.

You rebuild the map so that only the structure remains, then learn what this kind of test can and cannot remove.

Your task

    Simulation
    solution.pyLoading Python…
    Ctrl+Enter runs
    What Python can I use?

    Plain Python with math and, for matrices, slamkit (matmul, transpose, solve, inverse, identity). The data arrive as the dictionary D. There is no NumPy, random, json or copy in the browser runtime. Your code runs locally and never leaves this page.

    Hints

    What this lab teaches

    Stage 1 turns the log-odds argument of M8-T1 into counting: a cell that is hit repeatedly and rarely seen through is structure. It is graded on hidden rooms with walkers and a person who stops, by the number of ghost cells and the fraction of the real walls kept. Stage 2 is an experiment on the two thresholds and on the standing time, ending with the limit of the method.

    Why it matters

    Every dynamic-aware mapper rests on this evidence, however elaborate its machinery. Knowing what the evidence can and cannot separate tells you when you need semantics or change detection.

    Theory for this lab

    Advanced SLAM and Research labs

    1. M8-L1: Handle Dynamic Objects in Mapping: this lab.
    2. M8-L2: Compare SLAM Trajectories Using Evaluation Metrics
    3. M8-L3: Diagnose Localization in a Feature-Poor Environment
    4. M8-L4: Evaluate a SLAM System Under Controlled Failures

    Educational simplification: known robot poses, a 2D lidar without dropouts, people as discs, a 0.2 m grid, sampled ray traversal and hit/pass counting instead of a full log-odds update. Real mappers trace rays exactly in 3D, include pose uncertainty and use visibility checks or learned masks.

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