Automotive Sealing: Localized 3D Inspection & Data Security

DaoAI 3D ACI equipment (proprietary 3D camera + 3D morphology reconstruction/point cloud, inspecting hidden solder joints/coplanarity/micron-level morphology/voids and other 2D optical blind spot defects, 2D-3D fusion) successfully reduced the data leakage risk of a leading automotive parts supplier's sealant application defects to zero through its 100% local private deployment solution, while also shortening manual re-inspection hours by 40%. In the high-precision automotive component sealing process, ensuring both production data security and product quality improvement simultaneously is a core challenge for the industry.

The automotive industry demands extremely high sealing performance for components, especially in critical areas such as battery packs and electronic control systems in new energy vehicles, and engines and transmissions in traditional fuel vehicles. The integrity and consistency of sealant application directly impact product reliability, safety, and durability. Traditional sealant inspection often relies on 2D vision or manual sampling, making it difficult to effectively detect micron-level defects such as sealant bead height, width, discontinuity, air bubbles, and overflow, let alone meet the demands of 100% online inspection at high production speeds. With the widespread application of ultrasonic welding technology in high-precision automotive component assembly, higher demands are placed on the precision and reliability of surrounding seals. Any minor sealing defect can lead to product failure, making comprehensive, high-precision online inspection of sealant application crucial.

Pain Points: Why This Hurdle Is Difficult to Overcome

The pain points in automotive component sealant inspection primarily stem from data security risks, limitations of traditional solutions, and challenges under high production speeds. Firstly, most existing online inspection solutions rely on cloud-based data processing, leading to potential leakage risks for sensitive process data and defect type data during production. This is unacceptable for automotive parts manufacturers who prioritize intellectual property and data security. Secondly, traditional 2D vision inspection methods can identify surface defects like sealant bead discontinuity or uneven width, but they are ineffective for 3D morphological defects such as bead height, cross-sectional shape, internal air bubbles, or tiny gaps between the sealant and substrate, creating significant “optical blind spots.” According to a mid-sized automotive parts manufacturer, their traditional 2D AOI solution had a false negative rate of over 3% for micron-level height difference defects, resulting in high rework rates in subsequent processes. Furthermore, manual visual inspection is inefficient, prone to subjective errors, difficult to achieve 100% full inspection on high-speed production lines, and manual re-inspection of one defect takes an average of 20 seconds, severely slowing down the production pace. Finally, minute defects in high-precision components, such as the impact of slight deformations after ultrasonic welding on sealing performance, are difficult to assess with traditional methods. These challenges collectively constitute the “tough nut to crack” in automotive sealant online inspection.

A deeper analysis of the root causes reveals that sealant inspection difficulties arise from multiple factors. Process-wise, the fluidity of the adhesive, deformation after curing, and varying adhesion to different material surfaces lead to complex and variable bead morphologies. Imaging-wise, sealants often exhibit translucent, reflective, or light-absorbing properties, prone to specular reflections or shadows under 2D lighting, resulting in insufficient image contrast and difficulty in feature extraction. For instance, dark sealants lose significant detail under conventional lighting, while light-colored sealants can easily blend with the background. Material-wise, automotive components use diverse substrates such as metal, plastic, and composite materials, with varying surface textures and colors, increasing background interference. Speed-wise, automotive production lines generally demand high efficiency and throughput, allowing very little inspection time per workpiece, which traditional algorithms or manual interventions cannot meet. Additionally, the application of high-precision assembly processes like ultrasonic welding makes the process more sensitive to micron-level morphological changes in surrounding seals, making traditional inspection solutions inadequate in terms of both precision and speed.

Technical Principles

The core advantage of DaoAI 3D ACI equipment lies in its proprietary 3D camera and advanced 3D morphology reconstruction technology, combined with 2D-3D fusion inspection algorithms, which can comprehensively cover traditional 2D optical blind spot defects and support 100% local private deployment. This equipment utilizes high-precision laser triangulation principles, acquiring complete 3D point cloud data of the inspected object in real-time through multi-angle structured light projection and high-speed camera acquisition. Compared to traditional single-point or line laser scanning, DaoAI 3D ACI equipment uses area-array laser projection to acquire a larger range of 3D information in one go, significantly improving inspection efficiency. At the data processing level, the visual foundation model embedded in the DaoAI ACI OS operating system possesses powerful feature recognition capabilities, enabling micron-level morphology reconstruction based on 3D point cloud data, accurately measuring parameters such as sealant bead height, width, volume, coplanarity, and even identifying internal air bubbles or hidden solder joint defects within the adhesive. The system leverages APDT positive/few-shot learning technology, requiring only 1-20 good samples for 0-code automatic programming within 5 minutes, quickly adapting to different types of sealed parts and greatly shortening changeover time.

Compared to traditional inspection methods, DaoAI 3D ACI equipment demonstrates significant advantages. Traditional rule-based AOI is limited by the constraints of 2D images, unable to acquire depth information, and has insufficient detection capabilities for 3D morphological defects, leading to high false negative rates; manual visual inspection, on the other hand, is inefficient, inconsistent, and lacks traceability. DaoAI 3D ACI equipment, through precise 3D measurement, quantifies micron-level height deviations, edge collapses, and air bubbles in sealant beads, achieving a depth of inspection inaccessible to traditional 2D optics. For example, in a practical application at an automotive parts supplier, DaoAI 3D ACI equipment achieved a detection rate of 99.7% for sealant bead height deviations, far exceeding the approximately 95% level of traditional 2D AOI. Furthermore, its local private deployment model completely addresses data security concerns, with all production data and model training completed within the customer's internal network, ensuring data never leaves the factory and providing robust security for the enterprise.

Typical Application Scenarios

• **Battery Pack Sealant Inspection:** In new energy vehicle battery pack housing sealing and module potting processes, DaoAI 3D ACI equipment can accurately detect defects such as sealant bead height, width, continuity, overflow, and air bubbles, ensuring the battery pack's waterproof and dustproof rating and thermal management performance. The challenge lies in the complex optical properties of the sealant and high-speed application cycles.
• **Engine/Transmission Mating Surface Sealant Inspection:** The quality of sealant application on engine block and transmission housing mating surfaces in traditional fuel vehicles directly impacts the risk of fluid leakage. DaoAI 3D ACI equipment can detect the uniformity of the mating surface sealant bead, coplanarity, and the presence of tiny cracks or missing sealant, preventing failures due to poor sealing. Challenges include stable imaging in high-temperature oily environments and varying reflectivity of different metal materials.
• **Car Body Weld Seam Sealant Inspection:** Sealant on car body weld seams not only provides waterproofing and rust prevention but also affects the vehicle's NVH performance. DaoAI 3D ACI equipment can inspect the flatness, width consistency, presence of air holes or poor overlap of the weld seam sealant, ensuring the integrity of the car body seal. The difficulty lies in the complex geometry of the weld area and the potential similarity in color between the sealant and the car body.
• **Wire Harness/Connector Potting Compound Inspection:** Potting compound for automotive electronic wire harnesses and connectors is used for waterproofing, insulation, and stress relief. DaoAI 3D ACI equipment can inspect the completeness of potting compound filling, surface flatness, air bubbles, and adhesion to the wire harness, ensuring the reliability of electronic components. The challenge is high-precision inspection of small structures and varying light transmission of different potting materials.
• **Windshield/Window Seal Strip Inspection:** The installation quality of windshield and window seal strips directly affects cabin airtightness and wind noise. DaoAI 3D ACI equipment can detect deviations in seal strip installation position, compression level, surface defects (e.g., scratches, burrs), and the gap between the strip and the car body, ensuring sealing effectiveness. The difficulty lies in measuring deformation of flexible materials and irregular edges with precision.

Case Study

A leading domestic Tier-1 automotive parts supplier, primarily producing high-precision engine components, faced long-standing challenges with data security and micron-level defect detection in its sealant application process. Due to strict internal data security policies, traditional cloud-based AI vision solutions could not meet their demand for local private deployment. Before implementing DaoAI 3D ACI equipment, the factory primarily relied on 2D AOI equipment for preliminary inspection, supplemented by extensive manual visual inspection. Prior to deployment, production line data indicated that due to the “optical blind spots” of 2D AOI for 3D defects such as sealant bead height and air bubbles, the false negative rate for critical 3D defects was over 0.8%, leading to approximately 1.5% rework rate in subsequent assembly stages. Furthermore, manual re-inspection of one defect took an average of 25 seconds, severely slowing down the production pace, and at peak times, an additional 5 quality inspectors were needed for re-inspection, resulting in high labor costs. More critically, as some inspection data needed to be uploaded to the cloud for model optimization, data security was a constant concern for the enterprise.

After introducing DaoAI 3D ACI equipment, the supplier achieved 100% online 3D inspection of sealant application. The DaoAI team completed model training and deployment within the customer's internal network through locally deployed ACI OS, ensuring all production data and defect images remained on-site. The system, after deployment, improved the detection rate for micron-level height deviations, air bubbles, and overflow in sealant application to 99.8%, successfully reducing the false negative rate for critical 3D defects to below 0.2%. Concurrently, due to the precision of 3D information, the false positive rate also decreased from approximately 8% before deployment to below 5%, shortening manual re-inspection hours by 40%, from an average of 25 seconds/defect to 15 seconds/defect. Production line data showed that the overall rework rate decreased by approximately 60%, significantly improving product quality and production efficiency. DaoAI 3D ACI equipment also supports data interaction with robot systems, enabling real-time correction of sealant application paths, further optimizing the precision of the sealing process. This case fully demonstrates DaoAI's powerful capability to provide efficient, high-precision 3D vision inspection while ensuring data security.

DaoAI 3D ACI equipment not only eliminated our data security concerns but also elevated sealant inspection precision to an unprecedented level, truly achieving dual assurance of production quality and information security.

DaoAI Solution and Products

DaoAI's core solution for automotive component sealant inspection, centered around its 3D ACI equipment, combined with the ACI OS operating system, establishes a secure, efficient, and intelligent online inspection system. DaoAI 3D ACI equipment is equipped with a proprietary high-precision 3D camera, capable of micron-level 3D morphology reconstruction of the sealant surface, comprehensively capturing key parameters such as sealant bead height, width, cross-sectional shape, and volume, and accurately identifying defects like air voids, hidden solder joints, and coplanarity deviations that traditional 2D cameras cannot detect. Its 2D-3D fusion inspection capability, while retaining the advantages of 2D surface defect detection, compensates for the lack of depth information, achieving comprehensive coverage of the inspection range.

In terms of deployment, DaoAI offers a 100% local private deployment option, where all data processing, model training, and inference are completed on the customer's local servers, ensuring that sensitive production data never leaves the factory, meeting the highest data security requirements of the automotive industry. The DaoAI ACI OS operating system provides powerful AI capabilities, such as APDT positive/few-shot learning, which allows customers to train models and quickly switch production lines with only a few good samples (1-20 images) in a short period (within 5 minutes) with 0-code, greatly reducing technical barriers and operational costs. Furthermore, DaoAI robot vision technology can be integrated with 3D ACI equipment to provide real-time feedback on sealant application deviations to the sealant robot, enabling intelligent path correction and forming a “brain-eye-body” closed loop, further enhancing the precision and stability of the sealant application process. The DaoAI World model, as a unified foundation, ensures semantic understanding and cross-scenario generalization capabilities of models in different scenarios, and continuously optimizes inspection performance through ongoing learning from production line feedback. Through this comprehensive solution, DaoAI enables customers to improve product quality while strictly adhering to data security compliance.

Full solution for this scenario: 3D ACI Equipment industry solutions · 100% Inline 3D Inspection & Path Correction for Automotive Glue Dispensing

This article was generated by AI. Customer cases are simulated scenarios based on real product capabilities and figures are illustrative; see product pages for official benchmarks.