IntermediateTopic 67 of 102Manufacturing, Robotics & Systems

Path planning

A*, RRT and potential fields find collision-free paths.

In depth

Global planners find collision-free paths: Dijkstra, A*, D*, PRM, RRT/RRT*, potential fields; local planners (DWA, TEB, MPC) avoid dynamic obstacles. Consider kinematic constraints, costmaps, replanning and safety margins.

Key points

  • Configuration space
  • Optimality vs completeness
  • Costmap inflation
Example

A* on an occupancy grid finds the shortest route around furniture.

Why it matters

Path planning finds a route that avoids obstacles, so a robot can move safely and efficiently in a changing environment.

Where this is used

  • Planning a route for a delivery robot around people and furniture.
  • Finding a collision-free path for a robotic arm in a crowded cell.
  • Routing a drone around buildings in a city.

Frequently asked questions

What is Path planning?

A*, RRT and potential fields find collision-free paths.

Why is it important to understand path planning?

Path planning finds a route that avoids obstacles, so a robot can move safely and efficiently in a changing environment.

What does A* search do?

It finds the lowest-cost path on a grid or graph using a heuristic that estimates the remaining distance to the goal.

What is a rapidly exploring random tree?

A sampling-based method that grows a tree of collision-free states, which handles high dimensional spaces such as robot arms.

How is Path planning used in practice?

Typical applications include planning a route for a delivery robot around people and furniture, finding a collision-free path for a robotic arm in a crowded cell and routing a drone around buildings in a city.

What should I learn before Path planning?

Study "Localisation and mapping" first (topic 66 of 102 in Manufacturing, Robotics & Systems). It covers the groundwork this topic builds on.

What are the key points of Path planning?

Configuration space. Optimality vs completeness. Costmap inflation.

Can you give an example of Path planning?

A* on an occupancy grid finds the shortest route around furniture.

What comes after Path planning?

The next topic is "Sensor fusion", which builds directly on this one.

How difficult is Path planning?

It is classed as Intermediate in Manufacturing, Robotics & Systems (topic 67 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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