Path Planning
What is Path Planning in Humanoid Robotics?
Finding a collision-free route from a starting point to a goal location.
Path planning algorithms like A* or RRT compute efficient routes while avoiding obstacles, considering robot dimensions, and optimizing for various constraints.
How Path Planning Works
Path planning algorithms search for routes through a representation of the environment. Grid-based methods divide space into cells, marking obstacles as blocked and free space as available. A* algorithm evaluates cells based on distance traveled plus estimated remaining distance, expanding the most promising paths first. RRT (Rapidly-exploring Random Tree) grows a tree of random configurations, connecting them when collision-free. The planner uses the robot's shape and dimensions to check if paths are truly collision-free. Cost functions can optimize for shortest distance, smoothest path, or safest route away from obstacles. Dynamic path planning updates routes when obstacles move or new information arrives. The final path is often smoothed and converted to motion commands.
Types of Path Planning
- A* Algorithm: Graph search optimizing cost plus heuristic estimate to goal
- Dijkstra: Similar to A* but explores all directions equally
- RRT (Rapidly-exploring Random Tree): Sampling-based, good for complex spaces
- PRM (Probabilistic Roadmap): Pre-computes network of valid paths
- Potential Fields: Mathematical fields guiding robot to goal
- Dynamic Window Approach: Real-time local planning considering robot dynamics
- Visibility Graph: Connects vertices of obstacle polygons
Applications in Humanoid Robots
Path planning enables humanoid robots to navigate buildings, finding routes from current location to destination rooms or workstations. In warehouses, robots plan efficient paths between shelving and packing areas while avoiding other robots and workers. Outdoor environments require planning over uneven terrain and around dynamic obstacles. Multi-floor navigation plans paths including stairs or elevators. Emergency response scenarios need quick replanning when original paths become blocked. Energy-efficient planning selects routes minimizing battery consumption.







