First use of camera for barcodes in cold store

A camera from Accu-Sort has just successfully completed far-reaching trials on the automatic sorting system at Sainsbury's Frozen Food Distribution Centre

The cameras are rolling again at Elstree but this time Sainsbury's is directing the action! The camera in question is an Accu-Vision AV-3700 from Accu-Sort and it has just successfully completed far-reaching trials on the automatic sorting system at the Frozen Food Distribution Centre.

These were undertaken to prove the camera's superiority over laser-based systems at raising the read rates of bar codes on traded units.

This achievement is significant for two reasons.

Not only is this the first application of camera technology in the UK retail distribution environment but also the world's first in a cold store, in temperatures as low as -21 degrees C.

With over 3,500 units installed, Accu-Vision camera technology is the preferred choice of the postal and logistics markets worldwide where requirements are largely confined to reading black on white bar codes, thermally printed onto labels.

In retail the different coding permutations run into thousands, as each supplier is responsible for generating and printing their own bar codes.

Outer case codes can be pre-printed on Kraft stock in a multitude of colours or onto self-adhesive labels.

They can also be inkjet or thermally printed directly onto the carton.

To complicate the installation further, the Sainsbury's camera had to work in a freezer! The standard unit is rated for operation in 10 degrees - 40 degrees C but as Accu-Sort already had considerable experience in modifying its products for use in sub-zero temperatures, the company accepted the challenge with confidence.

At the Elstree Frozen Food Distribution Centre, existing Accu-Sort laser scanners had been exceeding industry standard read rates; with typical throughput they had been achieving read-rate percentages in the high nineties.

However, when even one percentage point improvement can mean a saving of many thousands of pounds, Sainsbury's began considering its options.

Each case that cannot be instantly decoded can add extra minutes to sort process, and ultimately may need to be manually scanned.

Although not significant as an isolated case, the problem grows exponentially with the multiples of products involved in just one week's throughput.

Converting Sainsbury's to camera technology was the brainchild of Dave Haddon, the Systems and Sortation Manager at Elstree.

Initial research included a fact-finding mission to Compaq Computers' new European Distribution Centre in Holland to discover how they had benefited from upgrading automated laser scanning to Accu-Vision.

Compaq were decoding 21 codes per case with a two-camera configuration and reported an 80% improvement in read rates.

Suitably impressed, Dave returned to the UK with a recommendation for his management team.

On the strength of this testimony, an Accu-Vision AV-3700 test camera was installed at Elstree but not before extensive work had been undertaken at Accu-Sort's research and development centres in America and Germany to enable the unit to withstand its sub-zero environment.

Accu-Sort pursued two options, first being to encase the entire camera in a sealed and heated cabinet but this was rejected as it was too cumbersome.

The second, which proved to be the perfect solution, was to install thermostatically controlled heat pads within the camera.

As the Elstree plant has de-humidifiers to ensure the air is dry, there is no danger of the camera lens icing-up.

Two further points of concern for Dave Haddon was how the camera would respond in the event of an extended power-failure.

Although not a problem for the primary laser scanners, the secondary laser scanners could take up to two hours to reach operating temperature after such a failure.

Secondly, could the high intensity sodium illumination used by the system raise the temperature of frozen products if the line stopped? Whilst no formal test was planned to determine the response of the camera during power loss, an outage in January this year provided the answer.

After a power loss of 50 minutes, which was long enough to lower the entire camera systems temperature to -18øC, the camera was re-booted and was ready for use within minutes.

Tests also proved that the nearest point of contact to an illumination assembly is one metre and at that distance there is no discernible heat-effect on the frozen product.

Accu-Sort was confident that during trials, the camera would be able to read at least 90% of Sainsbury's worst no reads, but in fact the results were substantially better than their conservative predictions.

For the initial trial, Dave Haddon deliberately chose a difficult commodity to test the camera's abilities.

The frozen product is very small, the label is often crinkled and the colour contrast is bad.

"It's a commodity item that is certainly not suited to automated sorting.

I therefore expected the trial to last for hours as the product is so difficult to read," he explained.

"But the AV-3700 read it first time with no problems." The camera was then left running and continued to successfully decode all other case codes including point-of-sale and EAN codes.

"And through plastic as well," adds Dave Haddon.

The trials continued with Dave Haddon presenting the worst of his all-time 'unreadable codes' to the existing Accu-Sort laser scanners.

They read 64% of them but the camera had no problem in reading the remaining 36%.

In all trials, the AV-3700 has shown a success rate of 100%.

The Accu-Sort AV-3700 is a third generation camera that uses'natural' light frequencies instead of 635nM laser.

Its high scan rate of 10 - 19,000 scans per second (compared to the scanner's 500) translates to faster acquisition of bar code data, allowing the code to be read even if much of it is damaged or poorly contrasted against its background.

A charge coupler device is the'eyes' of the camera that allows it to capture the image.

Its de-code engine utilises standard PC architecture and Windows NTJ software; the processor is a Pentium III 1 GHz model.

At Sainsbury's request, remote monitoring software is also installed allowing Dave Haddon to check the performance of the camera - even at his home! This complements Accu-Sort's Advanced Diagnostics Package that allows the remote interrogation of the system in the event of a problem.

As the camera system allows all no-reads to be archived, this information can be captured and read at any PC anywhere in the world.

There is no more guesswork involved in why the suppliers code does not scan and evidence can be supplied that is case or label specific.

Another major benefit of the camera system is the decoding angles it is able to achieve.

"Scanners decode at a maximum angle of 15 degrees" Dave Haddon continues.

"With the camera we're achieving up to 81 degrees, and in any orientation." This is important as it takes the onus away from the picker to put the case onto the automatic sorting system at a particular orientation.

Speed of operation and quality of read are assured across a wide spectrum of coding possibilities.

It is also significant, as it will rationalise the number of cameras needed to achieve Dave Haddon's ultimate aim of decoding five facets of a case in a single pass.

Standards dictate that bar codes should appear on the bottom third of the case but in reality variations do occur.

However, the camera's much wider angle of operation assures far greater flexibility and higher read rate.

Early indications suggest that a single Accu-Sort AV-3700 will successfully decode two sides of the case at the same time, reducing implementation costs significantly.

Thanks to the huge success of these off-line trials, Sainsbury's is now committed to implementing Accu-Sort camera technology across a range of UK sites.

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