Three Gates, One AR Baseline for Large Weldments
In construction machinery, rail transit, automotive components and metalworking, large structural parts, frames and complex assemblies are placed on the floor at goods-in and released only after inspection. Incoming checks, assembly confirmation and pre-shipment checks have long depended on human eyesight. Quality rests on individual experience, and results are hard to quantify, record or share. These workpieces are usually made in small order-based batches with large design differences between similar parts, so inspectors face constantly changing drawings and models, and consistency and efficiency both suffer.
Three gates, different objects, one baseline
Incoming inspection asks whether the supplier delivered to design. Assembly confirmation asks whether the build has missing or wrong parts. Pre-shipment inspection asks about the state of the complete unit. All three judge against the 3D design model, so each gate does not need its own station and tooling: one tablet AR terminal can call up the relevant model, and the basis shifts from personal experience to an objective model.
High-mix low-volume breaks fixed stations first
Many locations cannot be inspected by a fixed station, so the inspection method has to follow the workpiece. Tablet AR does not change how production is organized. The inspector works beside the part, and the checking action merges with the release decision, which suits a shop that places parts on the floor to wait for inspection.
The verdict is presence and orientation, not size
The tablet overlays the 3D CAD model on the real workpiece and identifies missing or wrong parts plus obvious position and orientation differences. The boundary matters: the difficulty is not measurement accuracy but bringing the design datum onto the floor so a difference is visible at a glance. Areas that need quantitative dimensional measurement still require a measurement solution alongside.
Zone patrol covers what one view cannot
The difficulty is size: one view cannot cover every assembly area, so inspection proceeds zone by zone with multiple viewpoints. The overlay renders the design model into the live scene, the inspector compares part and model directly, the difference step judges missing parts and orientation, and the recording step stores the process for sharing. The chain depends on alignment: only when alignment is accurate does the displayed difference reflect the actual workpiece.
No lights and no fixtures: what that costs
The operator only has to keep the terminal view over the inspection area; no dedicated lighting or fixture is required, so deployment cost is low. The price is that alignment is affected by site lighting and part attitude, and an area with poor conditions may need several angles before a stable overlay appears. Ignore that and the conclusion is unreliable.
Which workpieces land fastest
Parts that already have 3D design data deploy quickly. Scenarios with complex assembly relationships that fixed inspection struggles to cover gain the most from on-site flexibility. From a selection standpoint, AR comparison suits workpieces with complete 3D CAD, complex assembly relationships and mostly on-site checking. Results can be recorded and shared, replacing the untraceable nature of visual inspection. Specific outcomes are subject to site acceptance results.
Questions before selecting
Can one terminal serve all three gates?
Yes. All three judge against the 3D design model, and the relevant model is called per scenario, so no dedicated station is needed per gate.
What is the essential difference from visual inspection?
Visual inspection compares from experience. AR overlays CAD on the part, so the basis becomes the objective difference between part and design, and the result can be recorded and shared.
Can it run without complete 3D CAD?
It should not. Parts with existing 3D design data deploy fastest; incomplete models must be built first.
Are special lights or fixtures needed?
No. Only terminal coverage of the inspection area is required, but lighting and part attitude will affect alignment.