A magnet sensing portable autonomous device includes a platform. A plurality of wheel sets is coupled to the platform. A drive system is used for driving the plurality of wheels. An attachment mechanism is positioned on an underside of the platform for securing the device to a surface. A control board is used for controlling the operation of the device. In some embodiments, a drill spindle assembly is coupled to the platform. A drill feed assembly is coupled to the drill spindle assembly for raising and lowering the drill spindle assembly. A plurality of sensors are operable to sense one or more magnets disposed below the surface. A drive table is used for positioning the drill spindle assembly in an XY plane based on an output of said plurality of sensors.