Assessing implicit knowledge in BIM models with machine learning

http://link.springer.com/chapter/10.1007%2F978-3-319-24208-8_33

The adoption of Building Information Modelling (BIM) constitutes a radical shift in the way models in the building and construction industry are described. Traditional representations for architectural knowledge, such as architectural drawings, 3d models, technical descriptions and spreadsheets are transitioning into semantically-rich information models. Building related information no longer exists within discrete entities, but is kept in an interlinked context. BIM authoring tools for Design and Construction and Facility Management systems provide now semantic information about elements and spaces within buildings, their constituting elements, as their interrelation and performance. Currently huge efforts are put in place to create links between buildings, on local, regional and international level, through e.g. standardisation committees (buildingSMART 2014) or the Geospatial communities (Geospatial Media 2014), but as well through international research project, such as DURAARK (Durable Architectural Knowledge) (DURAARK 2015), a three year EU funded project on the creation and maintenance of semantic links between representations of buildings.
Building Information Models, in formats such as a Revit database or IFC, have become the bond that connects disciplines by streamlining data exchange and connecting the construction with the operational phases of a building lifecycle. Building related knowledge is herein represented in an object oriented way, holding building element geometry, properties, and its interrelation to other objects. These objects can be part of the described building, but in addition relate to external objects or other sources of information, including building element libraries. Information can be related to physical entities, like a wall, as well as to intellectual or organisational constructs, for example spaces or organisations. Hence, the model can support many facets of the construction phase, and in addition guide the building’s operation with Facility Management tools or the planning of retrofitting tasks.
The new class of information is directly machine-interpretable, as it conforms to a structured schema. The use of BIM models in current practice is however predominantly focussed on explicit information, such as property values, augmented with aggregate functions for the extraction of quantity information and clash detection based on geometrical inference (Tamke et al. 2014a). BIM models hold however information that is not explicitly stated, but lies implicit in the interrelation between the entities within a single model or in the interrelation of a large variety of models. And while years of practice train a building professional to immediately apprehend the workings of a space by means of merely symbolic two-dimensional representations, this information can currently not be assessed by machines. We ask, how these implicit second order descriptors can be assessed and whether this approach holds the potential to describe the qualitative aspects of a building.

Transcript

1. 1 / 20 2 / 26 / 13 Assessing implicit knowledge in BIM models with machine learning Thomas Krijnen Technical University Eindhoven, NL Martin Tamke Centre for Information Technology and Architecture, DK
2. 2 / 20 2 / 26 / 13 Background Building Information Modelling (BIM): Recent paradigm shift in the construction industry. Buildings structured as semantically rich models, with relational semantics and (parametric) geometry. IFC is an open standard to exchange such building models. Models are being used for design coordination and automatic (but imperative and hard coded) building code and requirement checking. Background
3. 3 / 20 2 / 26 / 13 DURAARK Durable Architectural Knowledge EU funded project started in 2013 Concerns the long-term digital preservation and semantic enrichment of building models Context
4. 4 / 20 2 / 26 / 13 Aims Offer insights into implicit information stored in building models As an alternative to explicit querying and rule checking mechanisms. Apply both supervised and unsupervised techniques. Aims
6. 6 / 20 2 / 26 / 13 Unsupervised learning Outlier detection based on geometrical descriptors of building elements segmented by element type {wall, window, column, …}. Unsupervised learning
7. 7 / 20 2 / 26 / 13 Example model Unsupervised learning
8. 8 / 20 2 / 26 / 13 Wall geometries Unsupervised learning
9. 9 / 20 2 / 26 / 13 Anomalies Unsupervised learning
10. 10 / 20 2 / 26 / 13 Results The algorithm has been able to identify the geometrical essence of building elements. Elements that deviate from this definition are identified and turned out to be misclassified by the authoring tool. Unsupervised learning
11. 11 / 20 2 / 26 / 13 Supervised learning Apply neural networks to categorize floor plans according to their use {non-residential, residential}. Supervised learning
12. 12 / 20 2 / 26 / 13 Features Supervised learning
13. 13 / 20 2 / 26 / 13 Space – wall - ratio Supervised learning
14. 14 / 20 2 / 26 / 13 Space – slab ratio Supervised learning
15. 15 / 20 2 / 26 / 13 Wall – column ratio Supervised learning
16. 16 / 20 2 / 26 / 13 Number of doors per space Supervised learning
17. 17 / 20 2 / 26 / 13 Average space gyradius and variance Supervised learning
18. 18 / 20 2 / 26 / 13 Dataset 35 IFC files of varying quality and complexity amounting up to 109 distinct floor plans manually classified 46 residential 63 as non- residential Supervised learning
19. 19 / 20 2 / 26 / 13 Results Successfully classified 90% of unseen samples [ training set (70%) cross-validation set (20%) test set (10%) ] Supervised learning
20. 20 / 20 2 / 26 / 13 Conclusions Data collection difficult impedes learning more interesting things Even well-established models contain flaws The quality of samples varies and exporters adhere to an individual IFC ‘dialect’ learn architectural features rather than picking up exporter idioms
21. 21 / 20 2 / 26 / 13 Further research ML an alternative perspective to explicit querying mechanisms and model checking. Autonomous quality assurance (typical clearance areas, confluence of specific types) by learning from conforming models. More ambitious classifications
22. 22 / 20 2 / 26 / 13 Assessing implicit knowledge in BIM models with machine learning Thomas Krijnen Technical University Eindhoven, NL Martin Tamke Centre for Information Technology and Architecture, DK