ST. LOUIS — Schnuck Markets Inc. says its cadre of shelf-scanning robots will double in size after the devices proved their worth in performing inventory checks and alerting employees when items need restocking or price tags are inaccurate. Another four of the grocer’s St. Louis-area stores are set to get robots as the grocer expands its partnership with San Francisco-based Simbe Robotics, maker of the devices. The expansion comes after Schnucks upgraded its fiber-optic network to allow for improved data collection.

Robots are ideally suited for repetitive tasks like inventory checking, remembering every single planogram, matching it to the shelf and producing an actionable report. However, the data they collect in the process is even more valuable.

The Simbe robots, nicknamed Tally, will help the grocer create a digital map of its stores as shopping moves into augmented reality, where shoppers could use smartphone apps to pinpoint where items are and get details about those items, Bob Hardester, Schnucks’ chief information officer, told the St. Louis ­Post-Dispatch.