1. Robot Biconnectivity Problem
Given a positive integer c, the RNB decision problem is to identify a sequence of movements M such that and GM is biconnected?
REQUIREMENTS
Work with robots that have minimal sensing
Distributed computation
Work with local information only
Improve connectivity incrementally

2. Step I: Compute Biconnected Components (Chang’s algorithm)
Step 2: Identify nodes to move
Compute relative bearing at articulation points
Identify nodes closest to each other belonging to different biconnected components
Compute cost of move
Step 3: Move
Command node with least cost to move
If edge is established, complete iteration else command next node to move

3. Algorithm Performance (simulation)
Algorithm resilient to error in relative bearing (upto 30 degrees)
Performance degrades gracefully with error
Significant increase number of vertex-unique paths between nodes

4. Relative Bearing Computation
Use radio signal strength (RSS) to compute bearing
Sampled RSS in local neighborhood of robot
Compute PCA to determine principal access of RSS gradient
Step distance – a tunable parameter
Average bearing error is ~20° for step size 1.5 m

5. Sample Experimental Trial

6. Algorithm Performance (Experiment)
Bearing Error
Coverage
Connectivity