A system for detecting targets and for positioning at least one work module over a particular target to perform a task thereon. The system includes a movable machine having a main frame, a drive mechanism for propelling the machine across a base surface, a sensor associated with the machine for detecting locations of at least one target positioned on said base surface, and an encoder assembly associated with the machine for obtaining motion data. The motion data includes at least one of the displacement and velocity of the machine across the base surface. Also included is a control unit for receiving the target locations from the sensor, for receiving the motion data from the encoder assembly, for determining a target distance for the drive mechanism to propel the machine such that the work module is generally aligned with a particular target in a target area, and for creating a destination signal indicating when the work module is operationally aligned with the target area.