Photogrammetry

AICON 3D DPA/Inspect - A great way to measure large size parts and fixtures

Photogrammetry is the process of taking measurements using cameras and over the years has developed with the advent of more sophisticated digital cameras into a highly precise way in which to obtain digital metrology data on features and key attributes of a huge array of different components and structures.

Some excellent uses for photogrammetry include the measurement of large aerospace tooling fixtures as well as automotive tooling systems, the measurement of railway rolling stock and large diesel engines in the mining and marine sector. Photogrammetry is also a very powerful tool to measure the before and after effects in deformation studies and temperature chambers etc. and are independent of movement of the part, making measurement in areas of high vibration or floor movement possible where other measurement techniques are not suitable.

The AICON 3D DPA/Inspect photogrammetry package is a powerful 3D measuring system that consists of a Nikon D3x high-end digital camera, both coded and uncoded targets, scale bars and reference crosses, special adaptors, AICON 3D Studio and PolyWorks/Inspector software that enables users to quickly and easily take accurate measurements on a large range of engineering components, as well as structures such as complex tooling jigs and fixtures.

The process of collecting digital measurement data using the AICON 3D DPA/Inspector system firstly involves the placement of coded targets around the object to be measured.  These targets allow the camera to "register" multiple camera shots together in the process of collecting a full 3D point cloud data.

Following the placement of coded targets, uncoded targets and adaptors are then placed on the particular features to be measured, and then scale bars and reference cross placed on the object and then the photography process begins.

Multiple digital photographs are then taken at different heights and camera orientation around the whole part and the photographs are sent to a suitable laptop computer using a Wi-LAN system attached to the camera.

The multiple camera shots are automatically processed in the AICON 3D Studio software with any photographs that have less than ideal resolution or definition shown with a red flag so that users can choose to either delete or take additional photographs to gain the necessary definition of the targets.

The point cloud output is then integrated into PolyWorks/Inspector software using the PolyWorks software plug-in for AICON 3D systems and the inspection project is completed with PolyWorks inspection reports generated.

Some clients have written automatic routines within PolyWorks (macros) to automatically process the AICON 3D photographs and produce final populated inspection reports.  This allows shopfloor employees with minimal metrology experience to produce full inspection reports of complex parts - simply by using a digital camera and a pre-arranged set of instructions for the placement of the photogrammetry targets.