IntermediateTopic 66 of 102Manufacturing, Robotics & Systems

Localisation and mapping

SLAM builds maps while tracking position.

In depth

SLAM builds a map while estimating the robot pose: approaches EKF-SLAM, particle filters (FastSLAM), graph optimisation (GTSAM), visual SLAM (ORB-SLAM) and lidar SLAM (LOAM, Cartographer). Loop closure corrects drift. Maps: occupancy grids, feature maps, point clouds.

Key points

  • Data association
  • Loop closure
  • Scan matching (ICP)
Example

A vacuum robot maps rooms with lidar SLAM.

Why it matters

Localisation and mapping let a robot know where it is and what the environment looks like, which is essential for autonomous movement.

Where this is used

  • Building a map of a warehouse as a robot drives through it.
  • Localising a robot against a known map using lidar.
  • Estimating the position of a drone in a building without GPS.

Frequently asked questions

What is Localisation and mapping?

SLAM builds maps while tracking position.

Why is it important to understand localisation and mapping?

Localisation and mapping let a robot know where it is and what the environment looks like, which is essential for autonomous movement.

What is SLAM?

Simultaneous localisation and mapping, the problem of building a map while estimating the robot position within it.

What sensors support SLAM?

Lidar, cameras, wheel odometry and inertial sensors, which are often combined for robustness.

How is Localisation and mapping used in practice?

Typical applications include building a map of a warehouse as a robot drives through it, localising a robot against a known map using lidar and estimating the position of a drone in a building without GPS.

What should I learn before Localisation and mapping?

Study "Mobile robots" first (topic 65 of 102 in Manufacturing, Robotics & Systems). It covers the groundwork this topic builds on.

What are the key points of Localisation and mapping?

Data association. Loop closure. Scan matching (ICP).

Can you give an example of Localisation and mapping?

A vacuum robot maps rooms with lidar SLAM.

What comes after Localisation and mapping?

The next topic is "Path planning", which builds directly on this one.

How difficult is Localisation and mapping?

It is classed as Intermediate in Manufacturing, Robotics & Systems (topic 66 of 102). It is an intermediate topic. Work through the beginner topics in Manufacturing, Robotics & Systems first.

Learning path

Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.

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