Drohnen-LiDAR

Using Surveying Drones to assist in Building Renovations


Business Geomatics highlighted how Wierig Profiltechnik is using integrated drone solutions from Microdrones that combine photogrammetry and thermal imaging to assist in the renovation of assembly halls.

Click the image above to download a German .pdf of the article

Renovation with a System

 

As Seen in Business Geomatics

March 2020

Wierig Profiltechnik, is a Siegburg-based company known for renovating assembly halls using high-quality components and materials from leading manufacturers. Consistent with its credo “Renovation with a System,” Wierig Profiltechnik works with its customers to craft a renovation plan that’s right for them, according to CEO and company founder Stephan Wierig. The company’s engineers tailor each step of that plan – be it a roof, the facades, doors and gates, windows, fire protection, a light-strip system, or any other aspect of the hall – to meet the customer’s needs.

 

Before and After pictures of a roof renovation

Fixed-price guarantee

On every construction project, Wierig Profiltechnik follows the principle of "renovation with a system." Wierig, who has an engineering degree, has integrated a fixed price guarantee for all measures into his company philosophy. "Above all, our customers should be spared expensive surprises," says Wierig. "Customers can expect from us that, following an intensive inventory and pre-planning to the exact square meter, we will provide them an offer that is at least as firm as the foundation the hall is built on."

But how does the fixed price guarantee work in an industry where surcharges for add-ons are commonplace?

Traditionally, multistage surveying has been common in the area of hall renovation. Under this model, buildings are roughly imaged to provide an initial estimate. All too often, after the company is hired and more precise surveying is conducted, customers receive unwanted surprises in the form of additional surcharges. Wierig Profiltechnik, however, offers a fixed-price guarantee of its initial estimate.

"Customers can expect from us that, following an intensive inventory and pre-planning to the exact square meter, we will provide them an offer that is at least as firm as the foundation the hall is built on," Wierig said.

How is this possible? The secret lies in the use of drone technology.

BIM-based drone surveying

Wierig Profiltechnik uses a Microdrones mdMapper1000 from the Siegen-based surveying specialist Microdrones. The pictures come from a Sony RxRII camera. Use of BIM-based drone surveying comes at an initial expense to the company, but it achieves “more transparency, reliability and effectiveness,” according to Wierig. “We need the higher accuracy of Microdrones’ solutions. Only with this forty-megapixel camera and a good lens can we get the necessary depth of field for creating models with an accuracy of up to one centimeter.”

To further process and evaluate the recorded data, Wierig Profiltechnik uses Metashape software from Russian software company Agisoft. The data is also overlaid with planning data in the 3D CAD software Rhinoceros 3D by Robert McNeel & Associates to help validate the renovation projects. Rhinoceros 3D uses curve technology modeling (NURBS), which is done with curves instead of polygons. With its use of adaptive mesh, this method is considered the most accurate on the market – ideal for renovation projects where accuracy to the centimeter is important.

Wierig, always seeking to make his company’s processes leaner and more efficient, said Wierig Profiltechnik will test a LiDAR solution with Microdrones scanner next month.

“With photogrammetry, we need a lot of ground control points. As a result, we have to transport huge amounts of data - which costs us a lot of time for every project,” he said. “LiDAR technology, on the other hand, creates a direct scan and a finished point cloud that only need to be combined. That could save us a lot of time.

“I'd rather buy an expensive high-end solution that fits my needs than a cheap system that doesn't do what I need it to do.”

an mdMapper1000 is used to obtain the necessary depth of field for creating models with an accuracy of up to one centimeter.

Investment

So far, Wierig Systemtechnik has invested around 70,000 euros in the entire surveying workflow. In addition to the drone, a GPS rover is used for calibrating the ground control points, and a computer is used to process data and run the software. The Siegburg-based company also uses a Flir Duo Pro, a thermal imaging camera, to detect thermal bridges – something not many of the company’s contemporaries do.

Weather conditions are crucial to detecting thermal bridges, Wierig said. They can be detected on early winter mornings in cloudy, but not rainy, conditions.

“We currently use thermal bridge detection mostly as a self-check,” Wierig said. “In this way, for example, we can see whether we have properly sealed the roof or whether there are still weaknesses in the construction.”

Fully automated process

Long term, the hall-renovation company plans to implement an automated process, from data acquisition to planning. In September 2018 Wierig Systemtechnik founded the ClickBuild joint venture with the fastening manufacturer EJOT, Wierig said. The company is now in its last phase of development.

“Here, hall models are created automatically, and can then be laid over the drone and object models. We expect to be able to fully automate the process by summer 2020.”

If you have questions about adding integrated drone systems into your workflow, CLICK HERE to speak with one of our representatives.