Udnyttelse af 3D scanning til kvalitetssikring i byggeriet

Abstract

Det er erfaret at fejl og mangler, er en vsentlig problemstilling i byggebranchen. Med udgangspunkt i erfaringer fra industrien hvor 3D scanning i enarrkke er benyttet til geometrisk kvalitetssikring, opstilles en hypotese omhandlende udnyttelsen af 3D scanning i byggeriet. Ud fra litteraturstudier, virksomhedsbesg og en feltundersgelse er der i projektet udarbejdet et system, der integrerer 3D scanning i byggeriets kvalitetssikringsproces. Systemet tager udgangspunkt i, at der under projekteringen udarbejdes en 3D model for byggeriet. I udfrelsesfasen scannes den opfrte konstruktion, som efterflgende sammenlignes med 3D modellen for at opdage eventuelle uoverensstemmelser. Systemet afprves ved hjlp af eksisterende software og hardware, hvorudfra svagheder ved systemet belyses.

The construction industry is characterized by many building defects which lead to high costs and a bad reputation. To change this situation the quality assurance/quality control from the design phase to the completion of the construction, are investigated. With inspiration from experiences in the machinery industry, a concept for geometric QC by means of 3D laserscanning, is developed. To demonstrate the opportunities in the concept, a practical test of existing software and hardware is conducted. The test involves a setup consisting of a design software (Tekla Structures 13), a laser scanner (Leica HDS 3000) and an inspection software (Rapidform XOV2). For demonstration, an existing precast building is scanned with a laser scanner, and compared to a model of the building in the inspection software. The result is a colormap that shows dierences between the "as built" data and the 3D model. A literature survey of 3D models identify a need for a common le exchange format in the concept, and IFC is identied as an opportunity. By investigating the Danish Construction Associations code of practice for precast and cast in place concrete, it is found, that there is a need for a data representation of tolerances or a new practice for describing tolerances. A practically test of the laser scanner concludes, that the most time consuming part of a scanning is the setup and preparation. As an opportunity for reducing this time, the use of xed sphere targets are identied. On the basis of four dierent scan resolutions, it was concluded that a resolution at about 10mm is suitable for most purpose in the construction industry. A study of comparison mechanisms identify three dierent methods whereof the method that is based on calculation of the shortest distance between a surface and a point, are tested through the inspection software. The test shows that the comparison mechanism is usable and that it is not necessary to sort out noise because of a lter opportunity. On the basis of the conducted tests and the literature surveys an evaluation of the applications of the concept was performed. The result was that the technology is applicable in its present form for control of prefabricated parts for the construction industry and for control of earthworks. If the technology should be usable for concrete work or mounting of precast, further development is needed.

A master thesis from Aalborg University

Udnyttelse af 3D scanning til kvalitetssikring i byggeriet

[Utilisation of 3D scanning for quality control in construction]