Patent US 5,337,149

An apparatus and method for creating a computer model of a large three dimensional object as data is acquired. The invention includes a measuring device, a computer that includes a computer aided drafting program, a data transmission device, and a viewing screen. The first embodiment of the measuring device includes a distance measuring device that takes measurements from a stable, moveable location. The location of measured points is calculated based upon the distance to the measured point and the orientation of the measuring device. In both the second and third embodiments of the measuring device, the location and orientation of the device is tracked by a microcontroller based on information supplied by an inertial measurement unit containing a plurality of linear and angular accelerometers. The second embodiment includes a distance measuring device and the third includes a measuring wand of a known length. The computer calculates the location of measured points with these two embodiments based upon the distance to the measured point as well as the location and orientation of the device when the point is measured. The apparatus and method operate such that the user interfaces with the computer aided drafting program and uses the measuring device as an input device to enter data into the computer aided drafting program. Thus, the user may create a complete model of the object solely by taking physical measurements of an object or space without any limitations on movement around or through it.