Case Studies > ITS Installs a Vision Categorisation System for a Tyre Manufacturer

ITS Installs a Vision Categorisation System for a Tyre Manufacturer

Industrial Technology Systems Ltd (ITS) has installed a replacement tyre classification system at a major tyre manufacturers’ site, with a Cognex In-Sight vision system. The tyre company required the new system to match the functionality of the original system, which had become unsupportable. 

ITS was responsible for designing a solution to inspect colour bands on each tyre and the tyre diameter, and transfer a identification code derived from the vision system results to an Oracle system and Allen-Bradley PLC-5 system. Tyres with incorrect features are automatically rejected by the system.

ITS worked with items provided by the company to help design the new vision system, including sample tyres with a variety of colour bands, samples of the company’s largest and smallest tyres, and the user requirements specification for the existing system.

The project was based around two Cognex In-Sight 5000 cameras – an In-Sight 5100 monochrome vision sensor and an In-Sight 5400C colour model.  High frequency fluorescent lamps provide front lit illumination of the colour bands and back lit inspection for the diameter check. A junction box and inspection PC with peripherals were provided, connected via an Ethernet network.  The completed system is able to inspect at a maximum speed of approximately one tyre every two seconds, including transfer of the tyre in and out of the inspection station.

The monochrome smart camera measures the internal and external diameters of each tyre, whilst the colour camera reports the band colours located on the tread of each tyre. The inspection PC is used to display captured images and results, and can also be used for camera configuration.

The monochrome camera is triggered (on the rising edge of the tyre) via an existing sensor. The colour camera is prompted by a network trigger initiated when the monochrome camera starts to operate. The colour camera passes the observed band colours back to the monochrome camera, which adds these to the internal and external diameters and builds up the supervisory code. The supervisory code is then transferred via the monochrome camera serial connection to the PLC and Supervisory system.

The supervisory code is checked by the PLC, and tyres with incorrect features are automatically rejected.

The monochrome camera is configured to run a single job file on power-up, providing a set of pre-configured vision tools and functions to perform the following inspection tasks:

  • perform a series of edge-detect operations across the centre of the tyre
    evaluate the maximum distance between each of the edges, and determine which of these represents the largest value
  • calculate the internal diameter, based on the largest maximum distance between edges multiplied by a calibration value
  • perform a series of sort edge operations on the detect operations across the centre of the tyre, and determine the column and row co-ordinates of each edge
  • calculate the external diameter
  • perform a read result operation from the colour camera
  • perform a write serial operation of the supervisory code

The custom view is configured to show results data, intended as an aid to configuration and fault finding activities.

The colour camera configuration is designed to carry out the following inspection tasks:

  • perform a series of colour histogram operations across the centre of the tyre
  • perform six HistMean operations for each colour histogram, which are used to return the mean red, green, blue, hue, saturation and intensity values for each colour histogram
  • carry out in-range evaluations on each colour histogram to verify that just one colour has been identified
  • perform a write result operation to the monochrome camera, writing the colour codes and the sequence number

Cognex’s In-Sight 5000 Series vision systems are the only available suite of vision systems which provide industrial-grade features standard.  Their rugged die-cast aluminium and stainless steel cases can withstand the punishment of vibration, and sealed M12 connectors and protective lens cover for IP67 rated protection against dust and moisture.

Cognex vision systems are used in factories around the world to automate the manufacture of a wide range of items and to assure their quality. Cognex is the world's leader in the machine vision industry, having shipped more than 400,000 machine vision systems, representing over $2 billion in cumulative revenue, since the company's founding in 1981.  In addition to its corporate headquarters in Natick, Massachusetts, Cognex also has regional offices and distributors located throughout North America, Japan, Europe, Asia, and Latin America.


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