Right now i need the robot to get to (x,y) but at a certain time the robot could recieve a new goal and then send him towards the old goal again before reaching the new goal, but as the robot moved the new goal i have to send the robot to get to the inicial goal depends on how far he moved before , how can i acomplish this? Because what i understand of the simplenavigationgoal is that the goal sent depends of the loction fo the robot and not of the map, so if i send goal(2,0) the robot will move two meters ahead. What im trying to do is to create a type of particle field, so i need the robot to get to (6,6) but in the way i could need to move it to "avoid" an obstacle and thus send a new goal to do so, but before reaching the goal the robot already has "cleared" the obstacle and i need to send it towards (6,6). But i dont know how to do this withought the information of where is the robot at that particular time, any idea how to acomplish this?