The Engineering Challenge

The classification of colored gemstones is traditionally a low-yield manual process bottlenecked by the irregular morphologies and varying optical properties of the stones. The engineering objective was to automate this classification process by weight, dimensional profile, and optical quality (achieving >1 piece per second throughput) without inducing mechanical damage to the high-value material.

Hardware Architecture & Resolution

G28LAB developed a hybrid automation cell that bridges standard industrial robotics with custom-engineered material handling and optical inspection units.

  • Proprietary Feeding Mechanism: Amorphous stones present severe singulation challenges. To solve the issue of irregular material flow, an in-house rotary drum (trommel) feeding system was engineered to operate in tandem with a conveyor belt, effectively separating and isolating individual stones for the camera payload.
  • Robotic Integration: An SHR3-600 SCARA robot was deployed to execute high-speed pick-and-place operations. It utilizes a custom-designed pneumatic vacuum gripper (End-of-Arm Tooling) to ensure non-destructive handling of delicate stones.
  • Computer Vision (CV): The optical unit utilizes proprietary algorithms to analyze 3D shape, volume, HSV/RGB color values, and internal inclusions (transparency). The vision system calculates and transmits exact spatial coordinates directly to the robotic controller.

Technical Execution

  • Control Architecture: A multi-threaded Finite-State Machine (FSM) was synthesized to synchronize the precision scales, optical tracking, and SCARA actuation. Network communication and logic execution are handled via Modbus/TCP.
  • Precision Weighing: The system integrates an array of six precision load cells to categorize stones by carat weight (down to 0.01g resolution) in parallel with the optical data acquisition.
  • Electromechanical Design: The physical architecture required custom Printed Circuit Board (PCB) and relay integration to manage the high-frequency switching of solenoid valves, vacuum systems, and the stepper motor drivers controlling the rotary feeding mechanism.