Plant Dimension Control Grid

Plant Dimension Control Grid (PDCG) is a reference network of hard points that are installed using portable metrology systems to control future engineering tasks.

(click for enlargement)

(click for enlargement)

There are generally two levels of accuracy available for the PDCG network. Level 1 PDCG is a low accuracy network of points installed generally throughout the plant. It is positioned and installed using a Leica TCA2003 precision total station. There are several targets configuration availalble. The network is accurate to 0.5mm-1mm. Level 2 PDCG is a high accuracy network of points installed locally in a specific area of the plant. It is positioned and installed using a Leica laser tracker.

There are several target configurations available. The network is accurate to 0.05mm-0.1mm for level II and 0.5 mm-2mm for level 1. Typically level II network is used for robot drift checks in a work cell.

A PDCG network can be a combination of vertical placement and/or horizontal placement. Vertical PDCG can be used to control machine elevation or reconstruction.

Once a PDCG is installed, it can be used to position all major machinery. It will also serve as a tie-in for all future engineering activities such as reconstruction and redesign. Another application of the network involves conducting metrology equipment field checks.

The PDCG network can also be used to enhance future activities i.e. 3D laser scanning to build a virtual factory. New technologies such as indoor Global Positioning System (GPS) can also tie into a PDCG network.

Floor monument (click for enlargement)

Total Station (click for enlargement)

Using a Leica HDS4500 non-contact scanner, plant facilities, including manufacturing equipment can be quickly digitized and captured into the computer for 3D visualization and solid modeling. The as-built condition information we can provide is critical in minimizing costly construction and design reworks!

For the PDCG work, we employ specialized metrology software known as Spatial Analyzer (SA). SA can increase the accuracy of the network using a feature called Unified Spatial Metrology Network (USMN). A viewer version is also available to the client for his own analysis with the job file.

In addition to graphical data in common formats such as IGES or Step, an actual job file is submitted which the client can view on his own computer. Furthermore, a coordinate table is provided as a back up. The data file can be pushed upstream into a database server like Oracle.

On the average, a PDCG can be installed in 1-2 days after initial measurement planning with the client. We can also provide an annual re-certification of the PDCG network. Additional points can be installed in the future as required by new conditions.