Excavator Bot | qzwang

Excavator Bot Design and Development (Nov 2017 - May 2024)

Skills: System Engineering, Mechanical Design, End-to-end R&D, System integration, Lab Testing, Field testing

Solidworks, Teamcenter PLM/PDM, FEA, Fast-Prototyping, Fabrication, Machining, 3D Printing.

Role: Lead Mechanical System Engineer, local and overseas tests coordinator

Product Site: https://www.offworld.ai/products/excavator

The Excavator is one of the most critical components of the Offworld Swarm Robotics Mining (SRM) architecture. The robot conducts rock face mapping before and during its precision excavation of ore, limiting waste rock excavation, enabling selective sorting of excavated material, and increasing downstream efficiency. It uses advanced controls and AI with customizable hard rock-cutting tools and configurations that suit the specific needs of the excavation profile resulting in the world’s first autonomous laparoscopic mining system.

I have been participating in the Excavator project since day 1 at Offworld, marking the longest duration of my career. Over the course of six years, I witnessed four major iterations of the robot's design, I as an engineer also matured alongside it. To date, the Excavator can perform a 4-hour nominal operation under minimal supervision, autonomously precondition some of the hardest rock faces in the world, and perform selective excavation while being fully untethered.

The Evolution of the Excavator: A Six-Year Journey

From the prototyping phase of the first iteration, I assumed the role of lead mechanical design engineer. My responsibilities include the complete design of the robot starting with the component level. I am responsible for parts and component selection including trade-off analysis between COTS and custom components. I develop complete subsystem and system-level assemblies based on detailed structural,electro-mechanical, and environmental analysis, ensuring the robot can withstand extreme forces and environmental conditions in operation. which requires a water and dust IP rating of IP54 or higher (all the way to IP67). I also performed detailed force analysis at the mobility and tool level. I work with the local suppliers and machine shops to ensure my designs can be built efficiently with the minimum amount of parts and manipulation at the machine shop.

As the project progressed, the OffWorld team implemented significant hardware and software upgrades, enabling the robot to increase both its physical volume and its capacity for autonomous excavation.

In 2021, the Excavator was deployed to a customer site, where it executed the world's first underground robot mining operation. The robot demonstrated seamless operation, and superior excavating Key Performance Indicators (KPIs), all served as a compelling testament to the OffWorld SRM technology. As the mechanical lead, I created operation and maintenance manuals, and also provided daily support during the 10-month test campaign by addressing onsite issues and acting as a liaison between the US support team and the local test team.

Scouting underground test area

Packing for shipment

Upon the robot's return to the Pasadena lab, the team embarked on the ambitious task of making the system untethered. Leveraging my comprehensive understanding of the system, I once again led the mechanical design and integration efforts. In a remarkable five-month timeframe, we successfully upgraded the design, procured custom and COTS parts, and assembled the strongest-ever Excavator.

Currently, the Excavator is under the supervision of the Offworld Robotics Software team, continuously enhancing its capabilities through autonomous and selective excavation algorithms. This six-year journey stands as a testament to the collaborative spirit and relentless pursuit of innovation within the OffWorld team, where each iteration of the Excavator brings us closer to redefining the future of autonomous mining.

Representing Excavator at International Astronautical Congress(IAC) 2019