Ok, the reason for my absence is I have been working on a project of building a multitasking Robot. Since the connection of Robots to Physics never entered my mind I assumed I have nothing of value to add to any discussion on the PhysicsForums. If anyone is interested in the problem that I am faced with. I'm searching for a software program that will allow me to create a path of travel using GPS coordinates with two ultrasonic range finders that uses a fixed X 0.0 Y 0.0 location on a grid. Would like to hear from anyone who is interested in this kind of project.