Fault-Tolerant Behavior-Based Robots

Use of robots in the real world requires robust systems that can handle diverse and changing environments. They must also contend with problems that occur within the robot itself.

A behavior-based robot design can be made more resistant to failure through the use of meta-behaviors combined with a hardware design that includes sensor and resources with overlapping capabilities. Meta-behaviors are used to handle fault conditions by changing the set of active behaviors. It is easier to create and debug each set of behaviors versus creating one set of behaviors that handle fault conditions implicitly. The latter tend to be more complex behaviors that are harder to debug.

The system developed using this approach includes robots that communicate using an infrared beacon and radio. They use video and touch sensors for obstacle avoidance. These devices provide additional overlapping capabilities. For example, the beacon and video support can be used to determine the relative position of another robot.

This design approach extends to the robot swarm. Robots cooperate using meta-behaviors to communicate error conditions and support information. In this case, a robot’s video sensor can provide a nearby robot with relative position information by detecting the nearby robot.