A drilling system is provided for drilling a workpiece. The drilling system includes a pattern generator configured to apply a pattern on a workpiece surface of the workpiece at a reference location relative to a target drilling location. The drilling system includes a drilling end effector, which includes a chuck configured to hold a drilling tool. The drilling end effector also includes a nosepiece configured to at least partially surround the drilling tool when the drilling tool is held by the chuck. The nosepiece includes an end portion that is configured to be held on the workpiece surface of the workpiece. The drilling end effector also includes a camera configured to acquire an image of an area of the workpiece surface that includes the pattern. The image acquired by the camera indicates whether the end portion of the nosepiece is aligned with the pattern on the workpiece surface.