An apparatus for automatically sensing the configuration of a damaged surface area and being provided an arc gouging tool, a welding tool, and a grinding tool whereby to gouge damaged areas and fill same with weld material to at least the surface profile of said surface in said working environment and grinding said filled areas flush with said surface of said working environment, said apparatus comprising a track, bendable to a profile enabling the apparatus to work without any collision with its environment while keeping full access to the work area, the geometry of said track being generally unknown to the control circuit of the robot, a motor-actuated robot member connectible to said track, said robot member having a motorized element provided with track coupling means engaged with said track for displacing said robot member at a predetermined base and position along said track, a working arm displaceably coupled to said robot member, said working arm having one or more working tools connectible thereto, a control circuit associated with said robot member for displacing same and operating said working arm and tool, a sensor connected to said working arm and having a probe to sense a distance which is measured along a normal of said surface or any surface calculated by said control circuit assumed to be representative of said surface in a delineated working environment of said robot member and working arm, said sensory feeding information data of said X and Y and Z coordinates to said control circuit to determined the geometry of the surface of said working environment and contour of areas in said working environment requiring a work procedure to be effected by said one or more working tools.