Walmart is expanding a shelf-scanning robot trial to 50 additional stores, including some in its home state of Arkansas. "Machines from Bossa Nova Robotics will roam the aisles to check for stock levels, pricing and misplaced items, saving human staffers the hassle of checking everything themselves," reports Engadget. The robots will be fully autonomous, though technicians will be available in case things go awry. They employ 3D imaging to dodge obstacles and make notes to return later if their path is completely blocked. From the report: Walmart stresses that the robots are there to supplement humans, not replace them -- to eliminate drudgery and the expenses that go with it. This helps workers get to the task of filling empty shelves, and that's a job that the company doesn't see ending any time soon given the difficulty robots still have when grabbing objects. "Store associates will always be better at that," Walmart's Martin Hitch told the Arkansas Democrat-Gazette. And the chief of Bossa Nova rival Simbe Robotics, Brad Bogolea, added that shelf checks can cost a major retailer hundreds of millions of dollars per year. However expensive the robots may be, they could pay for themselves very quickly. Whether or not the robots see wider use will, unsurprisingly, hinge on the success of this wider trial. Walmart posted a video about the shelf-scanning robots on its YouTube page.