What is the role of robot_radius when the actual work is done by inflation_radius?

Under the course path planning basics, chapter 5 Artificial Potential fields, it’s asked to play around with the values of robot_radius and inflation_radius to see the changes in the obstacle representation. It’s also asked to change both the values simultaneously.

Case 1:
I changed only the value of robot_radius, while keeping the inflation_radius as zero, there was NO change in the output, no matter the value of the radius.

Keeping the value of robot_radius constant and altering the inflation_radius resulted in drastic changes in the output.

Can you tell me then why was it asked to change both the values of robot_radius and inflation_radius simultaneously when changes only occur with changes in inflation_radius.

Hello @Joseph1001 ,

The inflation_radius value has to be always higher than the robot_radius value in order to create the buffer zone, as explained in the course. So, if you set the inflation_radius to zero you will see no effect.

Try changing the robot_radius parameter while keeping the inflation_radius to a fixed value higher than robot_radius and you will see the effect on the fields. For instance, set the inflation_radius to 1 and test different values for robot_radius between 0 and 1.