Lingchen PLC enables the perfect delivery of high-speed labeling equipment for mobile phone back covers

In the field of precision electronics manufacturing, accurately and efficiently labeling mobile phone back covers is crucial for ensuring product traceability and quality. Recently, Lingchen Technology successfully provided a complete control system solution for a mobile phone back cover module labeling machine and completed the project. This project not only demonstrated the stability and powerful functionality of Lingchen's PLC system in complex automation equipment but also achieved breakthroughs in accuracy, cycle time, and safety.

Precision process

The equipment's operational process is clear and efficient:
1. Initial loading/unloading: The operator places a full tray (10 pieces, 2x5 layout) into the loading bin and confirms the placement. Simultaneously, an empty tray is placed into the unloading bin and confirmed.

2. Batch loading and handling: The loading and handling module grabs 5 pcs product at a time and precisely places them one by one onto the loading station of the synchronized handling axis.

3. Synchronous precision shifting: The synchronized handling module simultaneously moves the products at the loading and labeling stations to the next station.

4. High-speed vision labeling:
· The label picking module removes the label and moves to the lower camera position.
· The lower camera precisely locates the label position, and the data is fed back to the PLC in real time.
· The upper camera simultaneously locates the product at the labeling station.
· The labeling module combines data from the upper and lower cameras to perform high-precision labeling.

5. Intelligent unloading and collection: The unloading and handling module picks up 1 piece of labeled product at a time, collects 5 pieces, and neatly places them into the empty tray of the unloading bin.

Project requirements and solutions

During the project implementation, several key challenges were successfully resolved:
1. Automated Clearing Mode Requirements: After startup, loading stops. After the current material has completed the labeling process and been placed in place, a 5-second wait occurs before the synchronized axis moves the labeled product to the unloading position. The unloading module retrieves the material and places it into the hopper, and the empty tray axis places the empty tray, achieving orderly unloading. Solution: Through precise program logic design, fully automated clearing is completed.

2. Eliminating Mechanical Interference: Interference between the retrieving module and the empty tray handling axis at retrieving position 1 → Add an empty tray avoidance position. Interference between the unloading module and the empty tray handling module at unloading position 1 → Add an empty tray avoidance position. Interference between the loading/unloading module and the hopper Z-axis → Add a loading Z-axis avoidance position and an unloading Z-axis avoidance position, respectively.

3. Safeguarding Manual Operation: Adding manual axis interlock logic to the program layer monitors and determines conditions affecting axis motion in real time, effectively preventing collision risks during manual commissioning.

4. Inspection System Optimization and Upgrade
· One-Click Calibration: Teach 12 points for center calibration. Once the camera is ready, calibration can be initiated with a single click, greatly simplifying commissioning.
· GRR Test: Dedicated to testing and verifying the labeling module's labeling accuracy (photo capture → feedback → labeling).
· Upper Camera Re-Inspection: Tests the results after labeling is complete and is used to check product status at the labeling station during initialization.
· Overcoming the Upper Camera Latency Bottleneck (700ms): Through program optimization, a waiting area for labeling was added, allowing the labeling module to advance a certain distance, effectively shortening the overall cycle time (CT).

5. Servo System Lean Commissioning (Resolving Noise and Vibration) Mechanism Optimization: Adjusted belt tension and synchronous pulley position to ensure friction-free travel; added a 3:1 reducer to the Y-axis of the loading/unloading modules to improve stability. Program Parameter Adjustment: Enabled servo startup parameters 16#2001:16#31 (Adaptive Notch Mode = 2) and reduced acceleration and deceleration. Deep Servo Parameter Tuning: Optimize key parameters such as velocity feedforward (Source 1, 100%), torque feedforward (Source 1, 80%), as well as position loop gain, velocity loop gain, and filter cutoff frequency.

6. Eliminate the root cause of abnormal cylinder lifting after labeling: During high-speed operation, a program logic bug caused the synchronous transfer flag to be repeatedly set, leading to incorrect cylinder operation and interference. Solution: Thoroughly optimize the program logic to resolve the duplicate flag-setting issue. Innovatively add labeling counts, transfer counts, and labeling counts, and perform real-time comparison and judgment. If the counts are inconsistent, the machine will immediately shut down and alarm, eliminating the risk of collision.

Excellent performance, outstanding value

This project successfully verified the control solution comprised of Lingchen PLC, HMI, remote I/O, and servo systems, demonstrating its core capabilities for the stable development and operation of medium-sized, complex automation equipment, meeting mainstream market demands. The seamless integration of the vision system significantly broadens application scenarios. The device's built-in intelligent position offset calculation function significantly improves operational convenience and changeover flexibility, effectively lowering the technical threshold for operators and shortening learning curves. The overall machine cycle (CT) reaches 3.5s (optimizable to 3.2s), with camera detection accuracy of 0.02mm GRR and 0.01mm CRR. This project established a set of reusable standardized development processes and solutions, creating a highly valuable benchmark case for Lingchen Technology in the field of precision automation, particularly high-speed vision labeling applications.