ROBOTIC METHODS FOR INSTALLING BATT INSULATION INTO WOOD-FRAME WALL PANELS IN BUILDING PREFABRICATION
Creators: Han, Xiao
Publisher: name: University of Alberta Library
Year: 2024

<p>In the light-frame building prefabrication construction industry, the utilization of robot arms is increasingly trending. In exterior wood-frame wall panels, which contain components such as wood frame, insulation and sheathing, automation has streamlined the construction of structural elements. In building construction, batt thermal insulation is extensively used due to its cost-effectiveness in achieving high thermal resistance. However, the automation of batt insulation installation in prefabricated building construction remains underdeveloped due to its deformable characteristics and currently relies solely on manual methods, which expose workers to various health risks. This thesis introduces two novel robotic methods, V-GLITPP and H-GLPPR, designed to automate the installation of batt thermal insulation into wood-frame wall frames without requiring complex modeling and simulation of its actual deformation. These methods ensure a tight fit within the frame cavity, eliminating visible gaps and deficiencies that could compromise thermal resistance. <br>
Each method utilizes a single 6-degree-of-freedom robot arm and a custom-built end-effector and is carefully engineered to overcome the non-linear and non-rigid mechanical characteristics of batt insulation during installation, which poses major challenges in robotic manipulation. Furthermore, both methods incorporate collision avoidance to prevent any potential collisions. <br>
The V-GLITPP method was initially developed under hardware constraints, with the goal of minimizing costs and utilizing existing equipment that was available in our lab. This method was tested on a scaled wood frame to demonstrate the feasibility of robotic insulation installation and employed a vertical pickup strategy with six major steps: (1) Grasp, (2) Lift, (3) Insert, (4) Tilt, (5) Push, and (6) Press. The necessary physical operating parameters for the insertion process, such as angles, offset, and force requirements, were identified to ensure the precision, efficiency, and repeatability of insertion. A prototype of the designed end-effector was used to demonstrate and validate the robotic method, which achieved a high success rate of 93.3%. Given its success in the scaled setup, the method faced several challenges when scaled up to full-size frames, thus leading to the second robotic method.<br>
The H-GLPPR method was developed for full size implementation and employed a horizontal pickup strategy through five key steps: (1) Grasp, (2) Lift, (3) Place, (4) Press and (5) Roll. The main operational parameters such as grasp location, clearances, angle, and displacements were identified and tuned to ensure repeatability, accuracy, and reliability of the installation process. Within our trials, the prototype end-effector, incorporating larger stroke dual parallel grippers and a roller, demonstrated a high success rate of 92.5%. Hence, demonstrating the effectiveness of the H-GLPPR for installation of batt insulation into full-size frames. <br>
The development of our V-GLITPP and H-GLPPR methods not only facilitates the expansion of the thermal insulation options available during automated prefabrication but also improves efficiency and safety for workers by reducing labor intensity. By filling a significant gap in the current construction practices, our methods facilitate ways toward the complete automation of wood-frame wall panel prefabrication.</p>