Case Studies > ITS and Cognex In-Sight Vision Sensors provide 100% Traceability and Quality Assurance for TRW Automotive

ITS and Cognex In-Sight Vision Sensors provide 100% Traceability and Quality Assurance for TRW Automotive

When manufacturing safety-related products in a just-in-time environment it is critical for automotive manufacturers to guarantee product quality and 100% traceability.

TRW Automotive, one of the world’s ten largest automotive suppliers, designs, develops and produces the widest and most comprehensive range of safety products in the industry, including Remote Airbag Sensors (RAS) for a number of major automotive customers.

With 2006 sales of $13.1 billion, TRW is one of the top financial performers in the industry. The company prides itself on the high quality of such key products as the Remote Airbag Sensor, and to maintain its commitment to excellence, recently purchased an inspection station from Industrial Technology Systems Ltd (ITS) to carry out quality checks.

ITS provided a vision system for checking the Remote Airbag Sensors as they are taken from the final stage of the production process, through to packaging. It comprises a manually-loaded sliding station which is charged when the slide returns, pushing it forward and locking it into place. Once the slide is locked in place the three-stage visual inspection commences.

The slide carries a number of quick change “nests” which are set up for different products to allow a quick changeover from product to product. Because of the need for a round-the-clock production operation, requiring a rapid changeover and reliable accurate inspections, TRW required one fixed set-up, to prevent changeover downtime and the risk of errors from mis-adjustment. This one set-up needed to be capable of accommodating twenty different products, thereby requiring considerable care during the design stage.

The vision system solution, designed and implemented by Industrial Technology Systems Ltd includes three Cognex In-Sight 5100 cameras, connected to a controlling PC which utilises the In-Sights’ Ethernet capabilities. Each In-Sight camera is physically positioned to inspect a different feature of the Remote Airbag Sensor.

The controlling PC is connected to TRW’s product-tracking system via a serial link which provides the central inspection station with product type and station configuration data. This in turn commands the correct combination of cameras and lighting units to be used for the product type, and which inspection programs are to be loaded into each In-Sight unit.

The PC switches the lighting units as necessary for each inspection via digital I/O, and triggers each In-Sight camera individually to ensure good quality, consistent and controlled lighting. The first inspection reads the RAS’ unique identifier (either 1D or 2D code) to identify the part to the product tracking system, and to allow the PC to save data to its hard disk for future retrieval.

At this point the In-Sight camera also reads the nest identifier to confirm the correct nest is in use, as well as the correct product is placed in the nest. A standard Direct On Axis LED light is used for this inspection.

The second inspection is for the correct presence, position and straightness of the electrical connection pins, and to check that the location splines on the electrical socket case are correct for that product type, and undamaged. The vision system can detect bent pins, short pins, missing pins, incorrect casings or damaged casings.

This inspection utilises three LED bar lights to illuminate the significant features of the varying products. The third inspection verifies that the mounting of the RAS (to allow fixing to the car body), is correct for that product type and that no damage exists on the portion of the fixing that is visible to the camera.

Due to the various numbers of products that can be inspected at this station, it was designed so that the In-Sight cameras are configured by the tracking system parameters to inspect different features, for instance a camera inspecting the fixtures on most products, is also capable of inspecting the plug on one particular variant.

If a failure is registered during any of the three stages, the slide locks until it is acknowledged by the operator on the touch screen, at which point the slide unlocks to enable the operator to remove the failed part. This failure is communicated to the tracking system which will not record the part, to prevent it being packed later. When the part passes, the operator returns the slide to re-start the cycle.


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