Robot workcell digital twin -demovideo

We built a real‑time, bi‑directional digital twin (DT) that links a FANUC CRX‑10iA/L cobot, a Cleco wireless nutrunner, and a LINAK‑controlled height‑adjustable table into one synchronized virtual–physical system. It proves SMEs can retrofit legacy equipment and still get continuous twinning (~0.5–1.0 s), operator‑in‑the‑loop control, and a path toward MES‑lite – without replacing their whole line.

At a glance

• Scope: Unit‑level DT for a robotic assembly cell (cobot + tool + legacy table)
• Twin type: Fully bi‑directional; virtual→physical and physical→virtual loops closed
• Twinning rate: continuous twinning at ~500–1000 ms end‑to‑end (sub‑second)
• Legacy integration: IT-Line table with LINAK controller retrofitted via ESP32‑S3 relays + ToF height sensor
• Comms stack: OPC UA (interoperability & semantics) + MQTT (IoT payloads), over TCP/IP (Ethernet/WLAN)
• Digital environment: Visual Components (3D scene & bindings) + Node‑RED dashboard + livestream (OBS)
• Use cases: Operator HMI, commissioning, path/process planning, remote demo/training
• SME context: Low‑cost retrofits, modular, standards‑leaning; ready to extend toward MES‑lite

Robot workcell digital twin -demovideo

What we built

Physical assets (the “real” side)

• FANUC CRX‑10iA/L collaborative robot (positions & I/O exposed to DT)
• Cleco CCBPW223 cordless nutrunner + mPro200GC controller (job triggers & OK/NOK status)
• IT‑Line height‑adjustable assembly table with LINAK controller (no native fieldbus → retrofitted)

Digital environment (the “virtual” side)

• Visual Components (VC): 3D cell, HMI buttons, light status, live values; VC Fanuc Connectivity for robot telemetry
• Fanuc iRProgrammer: Control the robot movements
• KepServerEx OPC UA: Central industrial interface & tag model
• Eclipse Mosquitto MQTT: Lightweight broker for microcontrollers
• Node‑RED: Web dashboard for direct actuation when VC isn’t needed
• UA Expert / MQTT Explorer: Integration testing & diagnostics

OBS / VC Experience: Live broadcasting for remote visibility

Digital twin IT-OT integration diagram

A. Cleco nutrunner → Robot → Visual Components (direct industrial path)

The Cleco nutrunner connects to its controller (mPro200GC). Discrete I/O signals between the Cleco controller and the FANUC robot controller allow the robot to act as a pass-through for job triggers and status. VC’s FANUC connectivity then exposes robot I/O and joint monitoring in the virtual scene. Due to safety restrictions, direct motion commands from VC to the robot are blocked; motion control runs via FANUC iRProgrammer on a PC in the same LAN, while VC handles I/O and state visualization.

B. Visual Components ↔ OPC UA ↔ MQTT ↔ Table (indirect legacy path)

The height-adjustable table uses a LINAK controller with no native industrial protocol. VC sends control intents to KepServerEx (OPC UA), which transforms them into MQTT messages that Mosquitto forwards to a Waveshare ESP32-S3 relay board wired into the LINAK controller through a proprietary cable. For feedback, a VL53L1X laser distance sensor on a microcontroller measures actual table height and publishes readings back via MQTT→OPC UA→VC, closing the loop and keeping the 3D model synchronized.

C) Support tools and comms stack
Node-RED provides a direct-control dashboard (HTTP front end) to actuate the table without opening VC – useful for commissioning and operator-only tasks. UAExpert and MQTT Explorer support debugging. For live sharing, VC Experience and OBS were used to share and livestream the DT (e.g., to YouTube) for remote visibility.

On protocols, the stack uses JSON payloads over MQTT for microcontrollers, OPC UA for central modeling/security/interoperability, and TCP/IP over Ethernet/WLAN as transport/physical layers – an approachable, scalable combination for mixed new/legacy fleets common in SMEs.

Performance: End‑to‑end round‑trip latency sits around 0.5–1.0 s depending on the path (direct robot/VC at lower end; multi‑hop legacy path higher).

What it can do (end‑to‑end functions)

1. True virtual↔physical control
2. Table: Operators can press buttons in VC to move the table, while the sensor-measured height is reflected back into the 3D model continuously.
3. Nutrunner: From VC, a program start can be triggered; the job OK/NOK status lights up in the scene.
4. Robot: VC shows live joint positions and I/O; for motion commands, iRProgrammer is used (safety).
5. Legacy device digitalization

Turns a LINAK table (no Modbus/OPC UA/PLC) into an addressable DT asset via IoT + MQTT + OPC UA with modest cost.

• Continuous twinning

Sub‑second synchronization supports operator‑in‑the‑loop tasks, commissioning, and training.

• Direct actuation w/o VC

Node‑RED web UI moves the table for maintenance/testing and simple operations.

• Remote visibility

VC scene, tags, and statuses are streamable for remote demos & training.

Why this matters for manufacturing companies, especially SMEs?

• Keep your machines: Retrofit legacy devices instead of replacing them.
• Fast adaptability: Data‑driven changeovers; real‑time feedback for small batches & variants.
• Plan with confidence: Use the twin to trial process changes and new cell layouts before touching hardware.
• Toward MES‑lite: The same stack can grow into tracking, scheduling, and KPIs on top of Node‑RED/OPC UA.
• Open, modular stack: Swap parts in/out (sensors, tools, HMIs) without re‑platforming.

Limitations & next steps

• Direct robot motion from VC: Restricted by vendor safety policies.
  Current solution: positions & I/O in VC; motion via iRProgrammer.
  Future solution: explore safe API surfaces / rate‑limited motion bridges.
• Cleco open interface: Stable OPC UA/Open Protocol link wasn’t available within project constraints.
  Current solution: pass job start/status via robot I/O.
  Future solution: pursue vendor DT‑ready specs or community middleware.
• Latency floor: ~0.5–1.0 s is fine for ops/visualization, not for tight servo loops.
  Current solution: minimize middleware, optimize sensor readings.
  Future solution: reduce hops (MQTT‑native VC features), wire critical links, QoS tuning.

• Transferability: Lab‑proven at unit level; needs field validation.
  Future solution: Pilot in a partner SME workcell, then scale to multi‑cell; add MES‑lite pages (tracking, reports).

Partners This project was carried out with the great support from Dynaset and LINAK, thanks to their provided equipment and technical expertise. Dynaset Oy is a company based in Ylöjärvi that develops solutions to increase the productivity of mobile machines by converting their hydraulic energy into driving power, such as electricity, compressed air, or mechanical movement. LINAK is a Danish family-owned company that develops and manufactures electric linear actuator systems – like those used in ergonomic desks, healthcare beds, and industrial automation – to improve movement and quality of life worldwide.