Overview
C3 Construction Robotics, Mar 2024 – Present
A suspended robot that autonomously coats large industrial structures. It hangs from the structure edge, traverses the surface while airborne, and must stay stable against geometry that is curved, irregular, and exposed to outdoor conditions. I was the lead engineer and technical lead from early proof-of-concept through live spray deployment and a later roller-based redesign, with full ownership across both the mechanical system and the software stack.
Mechanical Design
I owned the full mechanical design: cable suspension frame, dual-gimbal thrust-vectoring propulsion, spray gun and roller end effectors, and sealed electronics enclosures for outdoor use. Because the robot behaves like a pendulum, structural and actuation decisions directly shaped controllability — the mechanical and controls problems could not be solved separately. Designs were validated in SolidWorks Simulation, with topology optimisation used to reduce mass on 3D-printed parts without sacrificing field-load stiffness. Prototypes were built in-house from sheet metal, CNC-machined, and printed parts, with fabrication choices driven by cost, development speed, and how quickly a unit could be repaired between test cycles.
Control, Estimation, And Tooling
The ROS2 control stack coordinates drive, winch, and end-effector subsystems through serial and UDP hardware interfaces. Wall-relative control uses yaw stabilisation and vectored propeller allocation to keep the tool aligned to the surface across the pendulum’s working range, with gain scheduling as the arm extends. LiDAR-based surface estimation fused with IMU data provides the lateral offset and angular deviation the controller needs, staying usable even when outdoor returns are partial.
The operator UI runs on a handheld Linux device in Python and PySide6/QML, with live telemetry, camera feeds, YAML-defined workflow sequencing, and emergency control flows built for field use.
Technologies: ROS2 · Python · C++ · PySide6/QML · Embedded C++ · Serial / UDP hardware interfaces · NLopt · Sensor fusion · OpenCV · GStreamer · Electronics integration · SolidWorks · SolidWorks Simulation · FEA · 3D printing · Sheet metal · CNC
