I am moving a robot on a pre-determined path using pure pursuit. There also other dynamic objects intersecting the path and the routes of these objects are also pre-determined by me and use pure pursuit. Now, the robot doesn't know of these dynamic objects so I want to set a radius around the robot and make the robot stop or maneuver around the object once there is any object in that radius. My question is, how can I detect a moving object in that radius? I don't know how to approach this problem so any help would be appreciated.