AS/RS non-contact lasers reduce position errors

In the past, a manufacturer of automated storage and retrieval system (AS/RS) shuttle solutions relied on wheel encoders to indicate shuttle positions along rails. Although this solution has been used for years and continues to be used, it can be prone to positioning errors, typically caused by wheel diameter variation, roundness and slippage. These factors enable position errors to accumulate, requiring the frequent usage of a shuttle homing sequence.

To eliminate these challenges, the manufacturer selected non-contact Dimetix laser distance sensors.

The Dimetix D-series lasers can communicate as a serial synchronous interface (SSI) encoder, which is a common output of traditional wheel encoders. This protocol is absolute, so errors will not accumulate and the position will be saved, even if power is lost. An absolute accuracy of 0.03 to 0.11 inches has been achievable over a 16-foot range, depending on the integration method, along with the model chosen for each job.

The food and beverage industry poses unique design requirements and restrictions. Unique to this application is the ability to measure under a pallet to a target on the rail. The systems manufacturer met this challenge by using Dimetix lasers with their unusually small laser spot at far distances. If the spot becomes too large, it will interfere with the underside of a pallet. Another unique restriction is the requirement to operate in frozen food DCs, so it’s important that the laser distance sensor is capable of operating in temperatures as low as -40°C.

To determine the optimal laser distance sensor model and integrate the laser with its existing controls, the AS/RS manufacturer worked with the non-contact measurement sensors and systems manufacturer. As a result, Dimetix laser distance sensors are now integrated in a unique way to accommodate a compact shuttle design.

Laser-View Technologies
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