Construction Operation Assessment and Correction Using Laser Scanning and Projection Feedback

Lean construction (LC) and Building Information Modeling (BIM) support an integrated vision for short cycle plan-do-check-act cycles of planning and control in construction. However, operations control tasks, such as delivery of design information to the field, monitoring, progress evaluation and error detection are still largely manual and thus time-consuming, costly and error-prone. Innovations in construction technologies can be applied to reduce cycle time, waste, construction errors and the rework that necessarily follows. In this context, we propose application of a projection and scanning technology to provide workers with real-time information and feedback regarding the quality and accuracy of their handiwork. The goal is to achieve proper quality in the first iteration, with fully automated inspection, and no rework. As a proof-of-concept, we demonstrate the system using an example of wall plastering. The result of plaster application is difficult to measure in conventional means, and errors are difficult to detect. Our system monitors the progress of the procedure (Field-to-BIM), evaluates the surface flatness and projects corrections onto the surface itself, after optimizing with respect to industry standards and tolerances (BIM-to-Field). We demonstrate the concept in an experimental setup using a Trimble? TX8 laser scanner and an angled adjustable projector. The results show high precision detection of wall flatness deviations, of up to 2 mm accuracy.