Laser scanning has proven to be an excellent method for creating three-dimensional as-built models of the existing facilities in industrial plants. The method is highly automated, and it is becoming the method of choice for 3D data acquisition in a number of applications.
"Laser scanning is an efficient method for three-dimensional data acquisition. It allows us to compile large amounts of 3D data quickly and accurately. Cost-efficiency is another bonus", explains Jukka Mäkelä of Soil and Water Ltd (Maa ja Vesi Oy).
"The most important application is the creation of 3D models of existing constructions and equipment in industrial plants. The 3D models are needed, in particular, to provide data on the existing conditions for use in plant renovation projects and for intelligent 3D models, which are used for maintenance purposes.
Laser scanning is ideal for accurate modelling of complex or irregular surfaces, and the method is frequently applied for modelling infrastructures.
Three products
The laser scanning system consists of a tripod-supported laser scanner, which automatically compiles the captured 3D data into a 'cloud of points', and of analysis and modelling software that converts the 'cloud of points' into a 3D model.
"The method is based on automatic XYZ positioning by means of a laser beam reflected from the target. The target is scanned from different directions, and individual scans are combined to form a comprehensive cloud of points. Using supporting points measured with a tacheometer, the cloud of points is linked to an external co-ordinate system, Mäkelä explains".
"Laser scanning in fact generates three different products: a cloud of points, a complete CAD model, and a hybrid model. The hybrid model is partly in the form of a cloud of points and partly a CAD model".
"The cloud of points as such is a useful product, because it allows us to measure the dimensions between the points and to determine sections and volumes. Owing to the vast amount of data, it is difficult to transfer the cloud of points directly into CAD systems. Normally it is further processed and converted to a CAD model, using semi-automatic modelling software tools based on pattern recognition. We have used Cadmatic software, for example, in designing a paper mill for Mondi Paper in South Africa".
Minimising errors
Soil and Water Ltd, a member of the Infrastructure and Environment business group of the Jaakko Pöyry Group, has for a couple of years used the Cyrax laser scanning system on different projects. The method has proven to be functional and efficient.
"Automated data acquisition significantly reduces the probability of error. In renovation projects, laser scanning results in much more accurate information about both the position and the contents of the target. Thanks to this method, we no longer need to visit the plant during the project as frequently as we used to".
"An accurate 3D model means great surplus value throughout the whole lifecycle of a plant", Mäkelä concludes
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