Overviev

After weeks of development, programming, and simulation work, the digital twin for the Festo MPS (Modular Production System) is taking shape as a complete and coordinated automated process. This post provides a high-level overview of the project's current status, its accomplishments, and the tasks ahead. 

Current System Structure

As shown in the picture above, the whole system now consists of four interconnected workstations:

• Distribution Station
  Responsible for dispensing new workpieces and transporting them to the Pick and Place Station using a piston and suction cup.

• Pick and Place Station
  Handles lid attachment by placing the lid onto the base workpiece and then sending the assembled unit to the Sorting Station.

• Sorting Station
  Sorts workpieces based on user-defined HMI input. Colour detection and counting logic determine which slide receives the product.

• Deassembly Station (Dismantle Station)
  Handles excess or unused workpieces passed on from the sorting unit. Designed to remove lids and sort both components into bins for recycling or reuse.

Software & Simulation Progress

Siemens NX MCD:

• All stations have been modelled, refined, and joined into a single assembly.

• Motion controls, joints, rigid bodies, collision bodies, and sensors are in place.

• Signal mapping is linked to TIA Portal PLC logic.

• Object sources and sinks are being considered to complete the material flow.

TIA Portal + PLCSIM Advanced:

• Each station has a dedicated Function Block and Data Block for modularity.

• Signals are named using a clear convention (e.g., STATIONNAME_ACTUATOR, STATIONNAME_SENSOR).

• Gripper logic, lid pickup, and placement flows are programmed in SCL.

• HMI integration is active: users can input sorting orders in real time.

Current Challenges

• Gripper Lid Pickup Angle:
  The suction cup at the Pick and Place station most of the time picks up the lid at an angle due to its arrival on the slide. This affects alignment during placement and impacts downstream stations.
  
  

• Full Workpiece Simulation Blocked:
  Due to the above issue, the Deassembly Station currently processes only the base of the Workpiece. Once the lid issue is resolved, lid handling will be integrated into the dismantling logic.

Next Steps

• Fix the lid pickup alignment at the Pick and Place Station.

• Enable full deassembly of the lid + base in the Dismantle Station.

• Finalise Object Sink placement to simulate completed collection.

• Enhance the HMI interface with better visuals and user feedback.

• Conduct full simulation cycles with closed-loop logic across all stations.

Conclusion

The system is nearly fully integrated. Three of the four stations are nearly complete in logic and simulation. With just one mechanical issue left to refine, the MPS Digital Twin is well on its way to becoming a fully functional, modular, and automated production simulation.