wallfollowing

Wallfollowing is a navigation strategy used by mobile robots and autonomous agents in which the vehicle moves with one wall on a chosen side, typically maintaining a near-constant distance from that wall. The method is often employed to explore unknown environments, navigate corridors, or keep a boundary along free space. It is a local rule that does not require a preexisting map.

In practice, wallfollowing relies on proximity or contact sensors to measure distance to the nearby wall. A common variant keeps the wall on the left or right side throughout the motion. The robot adjusts its steering to maintain a target distance from the wall. Simple control schemes use bang-bang behavior, switching directions to stay close, while more precise implementations apply proportional or PID control to minimize distance error and stabilize the path along the wall.

Variations of the approach distinguish between distance-based wallfollowing and contact-based strategies, and may combine wall contact with loose steering to accommodate different environments. The technique is robust in feature-poor corridors and is easy to implement, but it can struggle in open spaces, at concave corners where it can become stuck, or in mazes with loops that detach the robot from a wall. To address limitations, wallfollowing is often integrated with higher-level planners or mapping, enabling switching between wall-bound exploration and global navigation.

Applications include autonomous vacuum cleaners, search-and-rescue robots, and exploration platforms in robotics competitions, where simple, dependable wall-adjacent movement provides reliable local behavior in complex environments.