An apparatus and method are described for acquiring tie-point target locations on a structure that eliminates the need for the user to manually identify features that can be used to register multiple scenes so that they share a single coordinate system. In the present invention, readily identifiable objects, known as targets, are placed on or near the structure. When the structure is scanned, the targets are identified and can then be used in other operations, such as registration.
A contact free rotary transformer assembly can be used to transfer power and information between a stationary portion and a rotatable portion of a laser scanning device. The rotary transformer can consist of a pair of substantially parallel ferrite rings, each having disposed therein a coil for passing AC current. The assembly can use an optical fiber positioned near a rotational axis of the transformer to transfer optical information between the stationary and rotary portions. The optical fiber can include two portions connected by a rotational connection in order to allow the portions to rotate with respect to one another while maintaining the light path.
The performance of a laser scanner is optimized in the field by automatically determining appropriate laser parameters for the scan location. A laser control system uses information such as the environmental temperature to select an appropriate range of start points for various laser parameters, such as pump temperature and laser currents. Test pulses over that range can be used to determine optimal operating parameters. In order to also meet safety regulations, the laser control system can use information such as range and pulse timing information to fire regularly spaced pulses that do not exceed acceptable exposure limits. Alternatively, the laser can be operated at a regular speed of about 24 Hz, or can be operated in burst mode where a burst of pulses creates what appears to be a brighter scan spot, but the time delay between bursts allows time for a blink reflex.
A non-contact surface measurement system, method and apparatus provides data to computers so that the topography of the surface of an object can be digitally recreated. 3-D images that define tool paths can be created from the data. Thus, cavities may be formed in selected materials by a tool. The appropriately selected materials safely encapsulate the object, which may be an artifact, art object, or other fragile or valuable item for moving or storage.