Laser scanners bringing accuracy into construction


Construction being the main focus this month, we’d like to look at what gadgets are perceived awesome and cool in the construction industry. Usually, the gadgets in this industry are gigantic machinery with powerful features. So get ready, ‘cause we’re about to get messy!
This week’s gadget isn’t as big as cranes and bulldozers though, but can produce such accuracy in humungous machines like airplanes that it deserves our respect!

The laser scanner! Yes, laser scanners.
A laser scanner offers remarkable functionality, allowing workers to capture not just two-dimensional photographs of a structure or scene, but three-dimensional models with measurements and other essential data. Laser scanners are used for site modelling, road remodelling, forensic documentation, safety and quality control, and may more applications. The laser scanner makes quick work of modeling jobs, allowing you to focus on the work at hand.
Laser scanning is a very efficient survey method to reduce costs. Surveys are realized by a laser scanner, which allows a fast surveying (scanning) of landscapes, they also provide highly effective inspections, structures and their furnishings and arrangements as well as installations. Laser scanners are also used for 3D surveys of large components and complex structures.

The benefits of using laser scanners in construction go on and on. They enable fast, reliable and inexpensive 3D surveys, which saves time and allows us to get to the fun part, building and erecting marvellous creations!

A good laser scanner we liked is the Nikon Metrology L100 Scanner. Whatever the product, be it a car, hand drill or mobile phone, customers expect its tightly toleranced parts to fit together and function perfectly and at the same time be of high quality and attractive design. But how do manufacturers ensure this level of precision without delaying the development and launch of the product?

The answer is to digitise the 3D shape and features of the prototypes with a non-contact laser scanner mounted on a coordinate measuring machine (CMM) or articulated arm and compare the results to the original CAD designs. It is much faster to inspect a part this way than to use a touch probe to take discrete measurements. With tens of thousands of points per second being captured by the laser and added to the point cloud, a complete inspection cycle is often between five and 10 times faster than tactile probing.

Furthermore, with the latter technique it is impossible to know what is happening between two adjacent discrete points, so the data is very sensitive to imperfections in the geometry being inspected. Parts that have flatness and roundness errors, edge rollover or burrs are particularly problematic. Radius compensation error is a further difficulty with tactile probing. When a stylus makes contact with the edges of a hole, for example, radius compensation may result in unexpected measurement points if a neighbouring surface is touched first.

Palesa Bogoshi