Robotic 3D Glue Bead Inspection System

In modern industrial and automotive applications, the quality of a glue bead directly determines the tightness, durability, and reliability of the final product.

Even minimal deviations in bead height, continuity, or position can result in leaks, reduced mechanical strength, or costly product rejections.

The customer required a fully automated 3D inspection system for glue bead applications that would ensure:

• Precise 3D measurement of the glue bead with accuracy down to 0.1 mm
• Control of bead continuity, height, width, and spatial position based on defined cross-sections
• Detection of missing glue, excess material, and bead misalignment relative to product geometry
• Automatic OK/NOK classification of inspected parts
• Full integration with PLC, HMI, and data storage systems

We designed and implemented a robotized 3D inspection system combining advanced vision technology with precise robotic motion.

The solution consisted of:

• A 6-axis industrial robot providing flexible and repeatable inspection trajectories
• A Keyence LJ-X8080 3D laser profilometer, enabling high-resolution, high-speed surface measurement
• A proprietary robot positioning and mounting system, ensuring stable distance and orientation relative to the inspected surface
• Custom-developed software inspection tools for bead analysis and defect classification
• Full integration with the customer’s automation environment using Profinet, including PLC, HMI, and databases (ISO / IATF compliant)

During system validation, several critical technical challenges were successfully addressed:

• Micrometer-level measurement accuracy (≥ 0.1 mm) achieved through optimized sensor configuration and data processing
• Stable robot trajectory control, ensuring consistent distance to the inspected surface for reliable 3D reconstruction
• Real-time processing of large data volumes generated by the profilometer
• Synchronization of the robot, vision system, and production line in real time
• Live visualization of inspection results on the HMI and automated archiving of data and images in databases and FTP servers

The system reliably inspected complex product geometries without slowing down the production process.

The implemented solution enabled:

• 100% in-line quality control of glue bead applications
• Reliable detection of bead defects, including gaps, excess glue, and positional deviations
• Automatic classification of products without operator intervention
• Full traceability of inspection results for every inspected part

• Elimination of subjective manual inspection
• Early detection of defects, reducing scrap, rework, and warranty costs
• Improved production line efficiency, without additional downtime
• Automated reporting and traceability, supporting quality audits and root-cause analysis
• Compliance with automotive quality standards (ISO / IATF)
• Tangible cost savings and increased process reliability

This case study demonstrates how combining robotics, high-resolution 3D vision, and intelligent data processing enables flawless quality control in demanding industrial applications. When every micron matters, automation must be precise, stable, and fully integrated – and that is exactly what this solution delivers.