Automation of additive manufacturing of concrete structures through closed-loop control of printing equipment.

Open Access
- Author:
- Henneh, Daniel
- Graduate Program:
- Engineering Design
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- March 18, 2021
- Committee Members:
- Sven G Bilen, Thesis Advisor/Co-Advisor
Nicholas Alexander Meisel, Thesis Advisor/Co-Advisor
Sven G Bilen, Program Head/Chair
Timothy W. Simpson, Committee Member - Keywords:
- Concrete
AddConLab
3D printing
3DCP
Automation
Cosed-loop
system
3D
Control
Robot
Additive manufacturing
Design - Abstract:
- This thesis explores the principle of closed-loop control to enhance the process of additive manufacturing of concrete structures by enabling more effective control of the printing equipment and processes. Unlike traditional extrusion based additive manufacturing systems such as desktop and industrial 3D printers, some major components of a 3D concrete printing system were not designed originally for concrete printing. Moreover, these components may be designed and manufactured by different vendors. Hence, integrating them to function as a single system can result in compatibility issues. For instance, the current printing setup in the AddConLab at The Pennsylvania State University consists a six-axis robot and a concrete mixer/pump from different vendors and a custom-fabricated build area along with multiple off-the-shelf components that originally were not intended for additive manufacturing of concrete. While such as setup is sufficient for most laboratory experiments, the real-world application of additive manufacturing of concrete will require better integration of the printing equipment, real-time communication between printing components and the control unit, and precise deposition of material. This thesis describes the development of hardware and software components to facilitate the closed-loop control of a concrete printing system. A central control panel was developed to serve as bridge between individual printing equipment components. A smart extrusion system (called the “Smart Nozzle”) was also developed to enable precise control of the deposition of the concrete material. Finally, the control unit of the concrete mixer/pump was modified such that it can be controlled remotely via a control panel. Software systems were developed for both the control panel and the primary control unit to facilitate the communication among the subsystems of the system. To determine the proper functioning of the Smart Nozzle, experiments with printing tool path with travel moves were performed. As a result, 3D concrete printing of structures with travel moves was demonstrated to be feasible using the Smart Nozzle and closed-loop control.