Cap liner presence and orientation
Distinguish a missing liner from a present but reversed insert using the material response.
Line solution
Test this on your samplesAssembly verification and error proofing
// Short answer
Assembly verification is a camera check at an assembly station that confirms every screw, clip, O-ring and connector is fitted and the right variant is used, before the part moves on. addaScan builds it on HIKROBOT vision sensors for single manual stations and on HIKROBOT smart cameras, area cameras and a code reader for automated stations, interlocked with the station PLC. An indicative installed budget for a typical application is R 100 000 – R 960 000 excluding VAT.
// At a glance
The station in three lines
- Faults caught
- Missing screws and clips, O-rings missing or wrong colour, wrong variant, connector not plugged or latched
- Configuration
- One HIKROBOT vision sensor at a manual station, or smart cameras, area cameras and a code reader on an automated station
- Line link
- PROFINET or EtherNet/IP to the station PLC (where the chosen HIKROBOT device lists it); result and image stored against the part serial
// Fit & limits
What this station will not do, and what it needs
What it will not do
- Torque and force: a camera sees that a screw is there, not that it is tightened; press-fit force and torque stay with the tools that apply them.
- Electrical engagement: a connector that looks latched may not be engaged; continuity and pull tests stay.
- Hidden parts: anything covered by a later part is checked before it is covered, or not at all.
- Vehicle body and paint: body-in-white and paint inspection at vehicle plants are outside this scope.
What makes it work
- A fixed part position: a fixture or pallet that presents each part the same way.
- Samples of every variant: good parts, plus parts with each fault you want caught.
- A station that obeys the result: an interlock in the station PLC, not only a lamp.
- Variant data: the variant being built, from the PLC, MES or the serial code.
// On South African lines
Automotive components in South Africa, and why stations are error-proofed
South Africa built 618 077 vehicles in 2025, up from 600 473 in 2024 (naamsa, 2026), and the same industry report puts automotive components exports for 2025 at R61 168m, with engine parts the second-largest category (naamsa, 2026). Much of that work is assembly at component suppliers: screws driven, clips and circlips fitted, O-rings placed, harness connectors plugged, and one variant built after another on the same station.
There is no South African rule that calls for a camera at an assembly station. The requirement comes from the customer: the right parts, fitted, on every unit, and evidence when a unit is questioned. Error proofing, or poka-yoke, is the practice of making a wrong assembly impossible or immediately visible. An assembly line inspection camera is one way to check, every cycle, what a person or a machine has just fitted, and to stop the part there if something is missing.
HIKROBOT’s own catalogue shows automotive error-proofing cases such as wheels, bearings and screw installation (HIKROBOT catalogue), and its Chinese site shows gearbox circlip and O-ring checks and an engine-bay check of wire harness plug-in state and colour (HIKROBOT CN cases). These are vendor cases, not addaScan installations. This page covers component and sub-assembly stations; body-in-white and paint inspection at vehicle plants are outside the scope addaScan builds.
What the assembly line reports, and what the station checks
| What the line reports | What a station checks | Where it stops |
|---|---|---|
| “A part went to the customer with a screw missing” | Missing screw detection: a screw head present at every taught position, and washers where the drawing has them. | A camera sees that the screw is there, not that it is tightened; torque stays with the nutrunner. |
| “Two variants look almost the same and the wrong one got fitted” | Variant by its visible features, colour, label or code; deep-learning classification for look-alikes, as in HIKROBOT’s wheel hub case. | Variants that differ only inside, or only in material, need a code or marking the camera can read. |
| “The circlip wasn’t in the groove” or “the O-ring is missing” | Circlip present and its gap position; O-ring present and the right colour, as in HIKROBOT’s gearbox case. | A clip that looks right from the camera’s side but sits half out of the groove needs a second view or a height check. |
| “The connector wasn’t clicked in” | Connector present, the right connector colour, and the latch or locking clip visible in its closed position. | A connector that looks seated may not be engaged electrically; the continuity or pull test stays. |
| “When the line is busy, people skip the check” | The result is wired into the station: the clamp or pallet is released only on a pass, and the image is stored against the part serial. | It needs the station PLC to enforce the result; a camera with only a lamp can be ignored. |
// The complete solution
Assembly verification station: hardware, software and installation
At a manual bench one vision sensor looks at the fixture and checks the part when the operator signals the job is done. On an automated station, a code reader identifies the part, two to four views check what was fitted, and the station PLC releases the part only on a pass.
[Schematic]Plan view, not to scale
Swipe sideways to see the whole drawing →
[1]: A pallet-in-position or fixture-closed signal starts the check.
[2]: An ID5000 code reader reads the part or pallet serial, so every result is stored against it.
[3]: A smart camera or area camera checks screws, clips and variant from above.
[4]: A second view checks O-rings, connectors and parts hidden from above.
[5]: The PLC releases the pallet only on a pass; a fail goes to a locked rework path.
Hardware
| Component | HIKROBOT example | Role in this station |
|---|---|---|
| Vision sensor (manual station) | HIKROBOT SC3000 colour vision sensor (MV-SC3016C-06M-WBN) with a HIKROBOT MV-LRDS-H-160-00-W ring light | Presence, count, colour and position at one fixture, without a PC |
| Smart cameras (automated station) | Two HIKROBOT SC6000 smart cameras (MV-SC6016M-00C-NNN, C-mount) running HIKROBOT VisionMaster; SC6000 multi-colour models switch red, green, blue and white light in software | Fixed views with variants and deep-learning checks |
| Area cameras and controller | Two HIKROBOT MV-CS050-10GM 5 MP cameras with MVL-HF2524M-10MP lenses and ring lights, on an MV-VC3302P-128G60 vision controller with VisionMaster | Views that need more tools, or one result combined across cameras |
| Code reader | HIKROBOT ID5000 code reader (MV-ID5050M-12S-WBN) | Reads the part or pallet serial for traceability |
| Connector pin height (option) | HIKROBOT DP-series 3D laser profiler: DP3120, or the dual-camera DP2000 HIKROBOT shows for connectors | Pin height and seating where a 2D view cannot decide; not in the budget below |
| Mounting, guarding and screen | Local supply: fixture-mounted brackets, guarding, panel and operator screen | Keeps every view fixed to the fixture; shows the operator which position failed |
Software and vision tools
| Tool or software | What it does here |
|---|---|
| HIKROBOT vision sensor tools (SCMVS client) | Existence, count and colour tools on the SC vision sensors, set up per fixture without a PC. |
| HIKROBOT VisionMaster pattern, blob and measurement tools | Locate the part, then check each screw, clip and O-ring position and the spacing between them. |
| VisionMaster deep-learning classification | Separate look-alike variants and parts with variable appearance; trained on your variants. |
| VisionMaster colour-processing tools | Check O-ring, cap and connector colours where colour identifies the right part. |
| Recipe per variant, linked to the serial | The PLC or MES selects the check set for the variant being built; result and image are stored against the serial. |
Installation and integration
01
Mounting and enclosure
Cameras on brackets fixed to the fixture or station frame, so the part is always in the same place in the image; guarded against knocks from tools, hoses and operators.
02
Lighting and shrouding
A ring or bar light per view, shrouded where machined metal reflects the plant lights; a coloured light where it lifts the contrast of an O-ring or connector.
03
Trigger and tracking
Fixture-closed, pallet-in-position or a PLC step signal triggers the check; the serial read ties each result to the unit.
04
PLC link
PROFINET or EtherNet/IP from the SC vision sensors, SC6000 smart cameras and ID5000 reader to the station PLC, as HIKROBOT lists for these devices; digital I/O at a simple manual bench.
05
Reject and confirmation
No pass, no release: the clamp or pallet is released only on a pass, a fail routes the part to a rework path that needs a supervisor to clear, and a vision fault stops the station rather than passing parts.
06
Recipes and operator screen
Variant recipes switched by the PLC or MES at changeover; the screen shows the image with the failed position marked.
// Indicative cost in South Africa
What this station costs, excluding VAT
Indicative budget for a typical application of this kind. Every project involves custom requirements (your products, line speed, layout, PLC and acceptance criteria), so the final price differs from case to case. A firm price follows the sample test.
- Low
- R 100 000
- one sensor at one station
- High
- R 960 000
- four views plus serial reader
- Basis
- Typical application of this kind, indicative
- South African rand, excluding VAT
- Prices as at 2 October 2026
- Travel (Gauteng): outside Gauteng quoted separately
// Included and excluded
The low figure is one HIKROBOT vision sensor at a manual or semi-automatic station, interlocked with the station PLC. The high figure is an automated station with four views, a code reader for traceability, a vision controller, the PLC and MES interlock, an image archive and automotive-style documentation. A 3D profiler for connector pin height is not in either figure and is priced separately. Changes to your fixtures, tooling and station mechanics, utilities and VAT are excluded.
Hardware is priced from public list prices converted at the ECB reference rate, plus freight, clearance and margin; engineering at R 900 – R 1 300 per hour. How these ranges are built →
Swipe the table sideways to see the high figure and the basis →
| Cost block | Low | High | Basis |
|---|---|---|---|
| Vision hardware (landed, with margin) | R 40 100 | R 343 400 | Low: one SC3000 colour vision sensor with a ring light. High: two SC6000 smart cameras, two 5 MP cameras with lenses and ring lights, an ID5000 code reader and a VC3000 controller |
| Software licence | R 0 | R 40 100 | Low: none, the vision sensor software is free. High: HIKROBOT VisionMaster standard licence for the controller |
| Local materials and reject | R 10 000 | R 70 000 | Low: bracket and cabling. High: fixture-mounted brackets, panel and operator screen |
| Engineering (recipes, PLC link) | R 27 000 | R 260 000 | 30 h at R 900 to 200 h at R 1 300 |
| Installation, FAT, SAT, training, documents | R 14 400 | R 124 800 | 16 h to 96 h; high case with automotive-style (PPAP-type) documentation |
| Project management | R 7 200 | R 62 400 | 8 h to 48 h |
| Travel (Gauteng) | R 1 500 | R 6 000 | Outside Gauteng quoted separately |
| Total (rounded) | R 100 000 | R 960 000 | Low: one sensor at one station. High: four views plus serial reader |
// Related technology
Which technologies this scenario uses, and why
The technologies behind this station, how much each matters here, and where each is explained in depth.
| Technology | Role | Why it matters in this scenario | Read more |
|---|---|---|---|
| Vision sensor (HIKROBOT SC1000–SC3000) | Core | Most checks at a manual station are presence, count and colour at fixed positions, which a vision sensor does without a PC. | Choosing a smart camera |
| Presence detection and counting | Core | Missing screw detection and clip counts are presence checks at known positions on a located part. | Presence and counting |
| PLC link and reject with confirmation | Core | Error proofing works only if the station cannot release a failed part; the interlock is the point of the system. | PLC and reject integration |
| Smart camera (HIKROBOT SC5000X, SC6000) | Supporting | Automated stations with several variants or look-alike parts need VisionMaster tools on an SC6000 or SC5000X. | Choosing a smart camera |
| Deep learning (classification, segmentation, DL OCR) | Supporting | Look-alike variants and parts with variable appearance are classified rather than measured. | Rule-based vs deep learning |
| Direct part mark (DPM) reading | Supporting | A serial on a label or marked on the part ties each result and image to the unit. | DPM code reading |
// Acceptance
How the station is proven before handover
Every station is accepted on your products, against numbers agreed in writing before the build. How we deliver →
01
Sample test
Good parts of every variant and parts with each fault (missing screw, wrong variant, unseated clip, missing O-ring, unlatched connector), imaged at the proposed views; the result says what is reliably caught and what needs another view.
02
FAT with challenge parts
Before delivery, a marked set of challenge parts, one per fault and variant, must each be stopped, and good parts of every variant must pass; the interlock and the vision-fault behaviour are tested with the station PLC logic.
03
SAT on the line
On your station, at production cycle time, the challenge parts are run again, and false fails and escapes are counted over an agreed run of production; results and images are checked against the serials.
Release machined assemblies and controlled component kits
A machined component may be geometrically correct but leave assembly without its O-ring, bush, retaining clip or screw. Inspect before the next operation hides those components, and distinguish an assembled part from a kit waiting to be assembled.
| Decision or event | Check or action | Acceptance boundary |
|---|---|---|
| Load | Confirm fixture occupancy and the expected variant | An empty nest must not produce a reusable pass. |
| Inspect | Check visible component count, location and orientation | Presence is not evidence of screw torque or press-fit force. |
| Release | Associate the result with the current cycle | No result, stale result or wrong recipe requires the defined hold. |
| Reload or rework | Invalidate the previous release and inspect again | A previous good image cannot release changed material. |
Use an indexed tray for kit completeness where all required items are visible. Unknown or occluded positions need a specified additional view or manual disposition, not a guessed count.
Machining inspection points · Machining operations rather than fitted components · PLC release handshake
// FAQ
Questions about assembly verification
What is assembly verification?
Assembly verification is a camera check built into an assembly station; the equipment is called an assembly verification system, an assembly inspection system or a camera-based error proofing system. After a step, or at the end of the station, a vision sensor or smart camera checks that every screw, clip, O-ring and connector is in place and that the right variant was used. The result goes to the station PLC, which releases the part only on a pass, and the image is stored against the part serial for traceability.
How much does assembly verification cost in South Africa?
An indicative installed budget is R 100 000 – R 960 000 excluding VAT, at 2 October 2026 prices. The low figure is one HIKROBOT vision sensor at one manual station, interlocked with the station PLC; the high figure is an automated station with four views, a serial code reader, a controller, MES link, image archive and automotive-style documentation. Both include engineering, installation, FAT and SAT in Gauteng. A firm price follows a sample test on your parts. This is a typical application: every project involves custom requirements, so the final price depends on your products, line and acceptance criteria.
Can a camera do missing screw detection and check torque as well?
It can do the first, not the second. The camera confirms a screw head is present at every position, and with a side view or height data that it is not standing proud. Whether the screw reached its torque is known only to the nutrunner or torque tool, so the two signals are combined in the station PLC: a part needs both to pass.
Can it check that a harness connector is plugged in?
It can check what is visible: the connector is present, it is the right colour, and its latch or locking clip is in the closed position. HIKROBOT shows a case on its Chinese site checking wire harness plug-in state and colour in vehicle final assembly, which is vendor material. Pin height inside a connector needs a 3D profiler. Whether the connector is engaged electrically is a continuity or pull test, not a camera check.
Can a poka yoke vision system check O-rings, clips and screws?
Yes, where each part is visible. O-ring presence detection checks the ring is there and seated in its groove; clips and screws are checked by shape or contrast at each position. A missing or wrong part holds the PLC interlock, so the assembly cannot be released until it is corrected. Computer vision for assembly verification and error proofing does not test fit, sealing force or torque.
How does missing screw detection work with a PLC interlock?
The camera images the assembly once the last screw is driven and checks every screw position. The result goes to the PLC, which keeps the fixture clamped, or blocks the next step, until all positions pass. Torque still comes from the screwdriver controller.
Is a vision sensor enough, or do we need a PC-based system?
For one fixture with a few presence, count and colour checks, a HIKROBOT SC vision sensor is usually enough and needs no PC. Several views, many variants, look-alike parts that need deep learning, or one combined result across cameras call for smart cameras running VisionMaster or area cameras on a vision controller. The sample test shows which checks need which device.
Does a poka yoke system with a camera work at a manual workstation?
Yes. At a manual bench the vision sensor is wired into the station so that the clamp opens, or the next tool is enabled, only after a pass. The operator sees on the screen which position failed and fixes it before the part can leave. The fixture matters as much as the camera: the part must sit in the same place every time.
Sources
- naamsa Automotive Trade Manual 2026 (vehicle production 2025; component export ranking) (industry report, checked 2026-10-02)
- HIKROBOT Machine Vision Smart Product Catalog 2025Q4: automotive error-proofing cases (vendor catalogue, checked 2026-10-02)
- HIKROBOT automotive industry cases on the Chinese site (gearbox circlip and O-ring; harness plug-in state and colour) (vendor case list (Chinese site), checked 2026-10-02)
- HIKROBOT automotive industry cases (wheel hub classification with deep learning) (vendor case list, checked 2026-10-02)
- HIKROBOT SC1000 vision sensor (tools and PLC protocols) (vendor product page, checked 2026-10-02)
- HIKROBOT SC6000 multi-colour smart camera (software-switched light, protocols) (vendor product page, checked 2026-10-02)
- HIKROBOT at VisionChina 2023: DP3120 laser profiler on connector defects (vendor news, checked 2026-10-02)
Related:
// Next step
Send us a good part and the faults that got through
Describe the line, the products and the fault. We test on your good and faulty samples and reply with a feasibility note and a budget.
Planning this inspection outside South Africa
Use the country guidance to prepare the line data, interfaces and delivery scope for a project assessed from Johannesburg.
Vision industrielle au Maroc
For a factory in Morocco, separate assembly checks from dimensional measurement and define the drawings and site interfaces. Country guidance in French.
Vision industrielle en Tunisie
For Tunisia, define part variants, fixturing and dimensional acceptance before selecting an inspection station. Country guidance in French.
Lecteurs code-barres en Tunisie
Identité des faisceaux et pièces par lecture de code ; guide en français.