On-Site Soil Additive Manufacturing with a Mobile Robotic Platform

Description

Advancements in robotic technology are ushering in a new era of autonomy in building construction, making it possible to employ soil–based materials through circular additive manufacturing. Multi–material additive manufacturing (MMAM) encompasses a variety of simultaneous material extrusion methods to characterize material properties but is currently constrained by the size of 3D printers (microscale) or the reach of multi–axis robotic arms (mesoscale).  

To extend the workspace of MMAM for soil–based materials, this research aims to:   

1. investigate different combinations of soil–based materials;   
2. explore the use of distributed, task–specific mobile manipulator systems;   
3. develop a control system to coordinate these mobile manipulators, plan the tasks and paths for each unit, and dynamically adapt material extrusion based on the properties of the materials.  

Program Development

A series of prototypes was produced with a single mobile manipulator and extrusion platform, using real-time path and flow-rate control. The demonstrated system comprised one UR5e robotic arm mounted on a Husky UGV, connected to a pump that extruded soil-based ink. The work was presented as an invited poster at the 3 Cavaliers Research Showcase Symposium, University of Virginia (May 2023).

Venue

Invited poster, 3 Cavaliers Research Showcase Symposium, University of Virginia (May 2023)

Role

Project initiator and Principal Investigator (School of Architecture). Conceived and directed the on-site soil additive-manufacturing application and contributed the computational task-scheduling method (Multi-Bot Task Scheduler); supervised the four-student engineering and architecture team that built the platform. Three-school UVA collaboration with Dr. Ji Ma (Material Science and Engineering, the soil-based material system) and Dr. Tomonari Furukawa (Aerospace and Mechanical Engineering, robotic autonomy and mechatronics).

Design Method

Computational Design (Multi-Bot Task Scheduler)

Fabrication Process

Mobile Robotic Extrusion (Husky UGV mobile base and UR5e arm; real-time path and flow-rate control)

Building Material

Mineral Composite (Soil-Based Ink, Sand, Kaolinite Clay)

Final Prototype Dimensions

Series tests W 500 mm × D 150 mm × H 100-150 mm (≈ 20 in × 6 in × 4-6 in); final wave-pattern wall L 1.5 m × H ≈ 100 mm (≈ 4 ft 11 in × 4 in)

Project Team

Ehsan Baharlou (School of Architecture, PI); Dr. Ji Ma (Material Science and Engineering); Dr. Tomonari Furukawa (Aerospace and Mechanical Engineering)

Student Research Assistants

4 students (2 M.Eng, 2 M.Arch)

Image Credit

Computational Tectonics Lab (CT Lab), University of Virginia, 2023

Acknowledgements

Supported by the University of Virginia 3 Cavaliers Program under the grant “Ecological Construction: Bio-Based Additive Manufacturing with Distributed Robotic Systems” (Principal Investigator, 2021-2022).