Behavior:Wall Following

Wall Following
Type	Behavior (Algorithm)
Requires Capabilities	Capability:Time-of-Flight Sensing or Capability:Ultrasonic Sensing, Capability:Differential Drive
Enables Activities	Activity:Maze Solving
Difficulty	Beginner
Status	Stub - Algorithm not yet implemented

Wall Following is a behavior (algorithm) that maintains a constant distance from a wall while moving parallel to it.

Overview

This is a stub page. This behavior is not yet implemented in any BRS robot. This page exists to:

• Document the algorithmic concept
• Invite community members to implement it
• Provide a starting point for algorithm design

Required Capabilities

This behavior requires:

• Capability:Time-of-Flight Sensing
• Capability:Ultrasonic Sensing
• Capability:Differential Drive

Enables Activities

Implementing this behavior enables:

• Activity:Maze Solving

Algorithm Outline

Wall following uses distance sensing and proportional control:

1. Measure distance to wall
2. If distance < target: turn away from wall
3. If distance > target: turn toward wall
4. Drive forward

For maze solving, consistently follow left or right wall until exit is reached.

Pseudocode

# Wall Following
TARGET_DISTANCE = 20  # cm

while True:
    distance_to_wall = read_distance_sensor()
    error = distance_to_wall - TARGET_DISTANCE

    turn_adjustment = error * gain  # Proportional control

    left_speed = BASE_SPEED + turn_adjustment
    right_speed = BASE_SPEED - turn_adjustment

    set_motors(left_speed, right_speed)

Implementation Challenges

• **Corners**: Detecting and handling inside/outside corners
• **Gaps**: What to do when wall disappears (doorways, openings)
• **Obstacles**: Handling objects protruding from wall
• **Sensor placement**: Angled sensors vs perpendicular sensors

Contributing

Want to implement this behavior? Here's how:

1. Study the algorithm outline above
2. Implement in your language of choice (MicroPython, C++, Arduino)
3. Test on a robot with the required capabilities
4. Create an Implementation page (e.g., YourRobot:Wall Following Implementation)
5. Update this page with algorithm refinements
6. Share working code on GitHub

See Also

• Behaviors - All behaviors
• Capabilities - Hardware required
• Activities - What this enables
• Robotics Ontology - How behaviors fit into BRS knowledge structure