01Personal project · 2026
Palletising robot cell — digital twin
An interactive digital twin of a KUKA palletising cell: real robot CAD, closed-form kinematics, a KRL-style program, cell I/O and a safety chain, all running in the browser.
- Axes6 + gripper
- Cycle≈ 8 s / crate
- Model39 MB → 1.1 MB
| Role | Design and development, from CAD conversion to cell logic |
|---|---|
| Context | Personal project · 2026 |
| Stack |
- 01STEPNX export, 39 MB
- 02OpenCascadetessellation, normals
- 03Per-axis splitjoint axes measured
- 04glTF + meshopt1.1 MB
- 05three.jsIK · program · I/O
Why
A portfolio says “robotics”; a running cell shows it. The goal was a cell a visitor can actually operate: start it, stop it, jog the axes and trip the safety chain — with behaviour that matches what happens on a real machine.
Kinematics
The six joint axes were measured directly on the cylindrical bearing faces of the STEP file (A2 at 330 / 1345 mm, A3 1350 mm above, 115 mm wrist offset, 1420 mm forearm, 240 mm flange). The model is split per axis and re-expressed around each joint.
Inverse kinematics is solved in closed form for a vertical tool, with A6 holding the crate orientation. Motions are PTP (synchronous joint interpolation) or LIN (Cartesian, IK every frame), with minimum-jerk profiles and a program override.
Cell logic
- Accumulating roller conveyor with photo-eye and pneumatic stopper.
- 3 / 4 / 3 interlocked layer pattern on a 1200 × 800 Euro pallet, with clearance for the side-clamp gripper.
- Automatic pallet exchange through a muted light curtain while the robot waits at HOME.
- A KRL-style program, I/O image and stack light all driven by the same state machine.
Safety
- E-stop: stop category 0, latched until reset.
- Interlocked door: protective stop in AUTO, restart requires a new start command.
- T1: manual jog at reduced speed, gripper locked while a load is held.
▶Try it