A laser beam control system includes an output aperture through which a laser beam is directed toward a target. In some embodiments, a fluid flow device can be calibrated using a single standard calibration fluid. Specific application of the solution is to an oral or skin surface target site. A body structure cavity may be bounded by a floor, and side wall portions and end wall portions that are separated by transition wall portions including a curved or segmented upper edge, with different wall portions being disposed at different angles of inclination. The one or more predefined criteria may comprise a feasibility of the path. The vehicle motion control apparatus includes a control object selection unit which is configured to determine priority of the control objects used for the vehicle motion control based on a priority determination condition, to select a control object from among the plurality of control objects.