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Implementation of Bug0 navigation strategy with a Turtlebot.

Bug0 Pseudocode:

1. Head toward goal
2. Follow obstacles until you can head toward goal again
3. Continue

To do so we use:

• Subscribe to Odometry to do positioning (known current position & goal)
• Subscribe to Laser Scan to detect objects
• Publish to Speed (Linear & Angular)

We have defined some global vars to customize the behaviour of the Bug0 algorithm: distance (m) detection of obstacte when the robot stop and begin to turn self.obstacle_threshold = 1

distance (m) obstacle_threshold+obstacle_threshold_add when the robot detects that the robot i more far starts to go fowrward to avoid it

• self.obstacle_threshold_add = 0.25

distance (m) in status 2 that the robot move to try avoid the obstracle and go to the goal after turn in front of obstracle

• self.distance_try_avoid_obstacle = 0.4

this linear variable * distance to goal lets to make a variable velocity

• self.linear_constant=0.5

max speed of the robot, if is very high is possible that the robot don't have enought time for stop whith obstabce

• self.max_speed=0.25

• self.accepted_error_try_avoid_obstable = 0.1

degrees/sec that turns the robot when detects obstable.

• self.turn_speed = 25

this linear velocity variable * distance to goal lets to make a variable linear velocity

• self.head_toward_linear_constant=1

this angular velocity variable * distance to goal lets to make a variable angular velocity

• self.head_toward_angular_constant=2