all. I am trying to construct the map of the environment by using the measurements from the proximity sensor in V-Rep. I have absolute position of the robot. So, I know the X1, Y1 coordinates of the robot with respect to inertial frame. And I also know the X2 and Y2 coordinates of the obstacle with respect to the sensor frame on the robot. My purpose is to calculate the coordinates of the obstacle with respect to the inertial frame. On my solution, I just sum up two coordinates like, (X1+X2) and (Y1+Y2). However, it didn't work. Isn't it correct?