ROS WEEK 3

Front

In ROS Navigation, what is the role of the Global Planner?

Back

It calculates a path from the starting position to the goal using the costmap.

Front

Why does ROS Navigation use a Local Planner in addition to a Global Planner?

Back

The Local Planner modifies the global path to adjust for real-time obstacles and smooth movement.

Front

A robot is navigating in a room but frequently gets stuck in narrow spaces. What is the most likely reason?

Back

The robot’s footprint is incorrectly set, making it think paths are blocked.

Front

In ROS Navigation, what does the Costmap do?

Back

helps the robot detect and avoid obstacles by assigning movement costs.

Front

What happens if the inflation radius in the costmap is set too high?

Back

The robot sees more obstacles than it should, making navigation difficult.

Front

If a robot using ROS Navigation does not detect obstacles correctly, what could be the cause? Options: The Global Planner is not set up correctly. The LIDAR is not publishing data to the costmap. The Local Planner is skipping obstacle detection. The costmap is missing the Global Planner’s data.

Back

The LIDAR is not publishing data to the costmap.

Front

Why does ROS use a TF (Transform) tree in navigation?

Back

It tracks the robot’s movement in relation to different coordinate frames.

Front

If a robot is moving but the TF transform between base_link and odom is not updating, what is the result?

Back

The robot moves in place without actually changing position in ROS.

Front

Which of the following causes odometry drift in ROS Navigation?
Options: Using GPS instead of wheel encoders., The robot moving in a perfectly straight line for too long., Cumulative errors from wheel slip and sensor inaccuracies., The Global Planner changing the robot’s goal location mid-navigation.

Back

Cumulative errors from wheel slip and sensor inaccuracies.

Front

A robot using ROS Navigation stops moving even though it has a valid path. What could be the problem? Options: The Global Planner is running too fast for the Local Planner to follow. The Local Planner is not generating valid velocity commands. The costmap is full of obstacles, preventing movement. The TF transform between map and base_link is too small.

Back

The Local Planner is not generating valid velocity commands.