When an autonomous floor scrubber was rolled out in Walmart's Bonney Lake store last month, shoppers mistook the teal blue scrubber zipping down the aisles for a runaway machine, said manager David Klein. "Some customers are a little freaked out."

Klein said the Auto-C robot has relieved his employees of several hours of cleaning every evening, and has allowed him to avoid hiring another maintenance worker on the previously understaffed team. The 4-foot-tall scrubber, which resembles a riding lawn mower but is considerably quieter, uses sensors to scan its environment and to avoid people or objects in its way.

The San Diego-based tech company, called Brain Corp., that makes the Auto-C robot's operating system, also provides the software that powers autonomous floor cleaners at Seattle-Tacoma International Airport.

At Walmart, the automated machines are just part of a push to bring this pioneer of big-box discounting into the future of brick-and-mortar retail, with implications for its workforce that are still unknown.

Last month the retail giant said it plans to spend $36 million on the remodeling of seven Washington stores, as well as the deployment of autonomous floor scrubbers, dozens of FAST unloaders akin to smart conveyor belts, and 16-foot-tall vending machines called pickup towers that dispense products ordered online.

Rivals such as Kroger and Seattle-based Amazon—which acquired Whole Foods in 2017 and launched a still-small chain of cashierless convenience stores called Amazon Go—have pushed Walmart to compete for customers by rolling out automated that offers convenience while keeping prices low. Meanwhile, the low unemployment rate and low corporate tax rate has spurred it to raise wages, increasing the allure of automation.

Artificial intelligence technology also allows the machine to map the layout of the store during a training ride and to continuously adapt to its surroundings, according to Brain Corp. But the machine occasionally needs help from humans, so it has a seat that is cordoned off by yellow straps in case the robot runs into an obstacle it can't outmaneuver and a Walmart worker needs to put it into manual mode.

At rest in the back room of Walmart, the new autonomous floor scrubber stands near three manual ones that have been retired, their surfaces speckled with dirt and hoses haphazardly strewn about the handles. Klein said he plans to sell them.

Nearby, a conveyor belt churns as it scans boxes of items coming off a truck. It spots the product codes and separates the items into piles for workers to quickly restock the shelves.

According to a recent report by research firm CB Insights, "as the lines between physical and digital retail continue to blur," retailers are increasingly experimenting with automated checkout technology, relying on AI to manage inventory and using brick-and-mortar stores as fulfillment centers for online orders. For workers, said labor law professor Charlotte Garden of Seattle University's School of Law, the question is whether the expanded automation will mean they are redirected to other tasks or some of their hours are eventually cut.

Klein said the innovation investments are making employees' jobs easier and increasing store revenue. The FAST unloader has increased the availability of items on shelves by 2 percent, which he estimates has resulted in the store gaining an additional $1,000 to $2,000 a day in sales.

Despite the new unloading technology, the Bonney Lake location has actually added 200 additional hours to the afternoon and evening stocking team shift since January as the company pivots toward constantly replenishing the shelves, Klein said. Previously, employees struggled to restock the depleted shelves during the day.

But it actually takes employees longer to unpack the trucks with the automated machine than it did during the days of manual unloading, he admitted. "The goal of this is not to unload faster," Klein said as a case of popcorn whirled past on the conveyor belt. "(It's) to get product to the floor faster."

No employees have lost hours or changed positions in the past four months due to the rollout of new technology, Klein said. Other aspects of Walmart's online push have meant hiring: Thirteen workers have been hired at the Bonney Lake location, and nationally, 40,000 online grocery personal shoppers have been added to stores since 2017. An hourly manager and assistant manager have also been hired to lead the Bonney Lake location's e-commerce team, whose roles include fetching items for the pickup tower, personal shopping and curbside pickup.

"We've always been a company that's all about saving customers money," said Walmart spokeswoman Tiffany Wilson. She said the technology initiatives are automating tasks workers don't want to do, and the company is "then upleveling their jobs, upleveling their skills and empowering our associates with technology so that they can then, in turn, serve our customers a lot better."

Labor-law expert Garden isn't surprised that employee hours are increasing during the initial deployment of technology, when they need additional training. "If I were to make a prediction about the medium term, I'd anticipate that the pickup towers could result for more work for employees," because they have to load the machine, and also help customers use it. The unloader and floor scrubber devices "will result in either less or different work for employees," she predicted. Employees who now do those jobs might be redirected to do different things, including running and troubleshooting the machines, "or they might see their hours cut."

Rapid deployment of new technology can be "slow and painful," and because "new tasks require new skills ... a mismatch between skills and technologies is bound to complicate the adjustment process," wrote MIT professor of economics Daron Acemoglu and Boston University assistant professor of economics Pascual Restrepo in a paper last year on "Artificial Intelligence, Automation and Work."

Andrea Dehlendorf, co-executive director of Organization United for Respect, a nonunion group of Walmart employees, fears that Walmart's innovations will disempower workers. She said technology could be introduced to help workers "really do the work, take care of the customers and do things better, but instead it is being introduced just to leverage cost savings instead of reinvesting that money in the workforce and paying the people who stay more."

The advocacy group did an online survey asking Walmart employees how they felt about the rollout of new technology and automation in their stores. "Not one person said that the technology is going to make my job easier," Dehlendorf said. One worker even commented on the survey that "they're just trying to replace us all and don't care if we die."

Accomplishing economic stability when incorporating technology into the workforce is the major challenge of our time, said Dehlendorf. "We need to make sure that as technology is integrated into work that it's doing it for the benefit of working people and that it's doing it for the benefit of humans in our society, not just the ... corporations or the shareholders."

Unionizing has historically provided the main avenue for employees to claim a stake in the transformation of their jobs, according to labor law professor Garden. Walmart, by contrast, has long drawn criticism from labor unions for shutting down stores where employees have attempted to unionize.

"If Walmart was unionized, it would have to bargain with its employees' union about these changes," Garden said about the deployment of automated machines. "As it is, Walmart can implement them unilaterally, and employees' main recourse if they don't like what is happening is to quit."

Along with the deployment of artificial intelligence technology in Walmart stores have come privacy concerns. In an Intelligent Retail Lab it is testing in a Walmart on Long Island, thousands of high-resolution cameras monitor shelves so workers can restock items, reported The Associated Press.

At the Bonney Lake store, the rollout of the automatic scrubber and unloader will be joined in the autumn by a robot that scans shelves to determine item availability and identify incorrect prices. The machine, called Auto-S and made by San Francisco-based robotics startup Bossa Nova, drives autonomously through aisles and uses a 3-D camera that gives it a computerized view of its surroundings.

The shelf scanner only gathers information about products and the cameras are turned off once it encounters humans, said Bossa Nova co-founder and chief business officer Martin Hitch. "In order for our cameras to work we have to shine bright lights and those lights are dazzling, so when we see a human we turn everything off to ensure that we're not shining lights on them," Hitch said.

The company plans on sticking to robots that identify inaccuracies, and not ones that replace humans by also restocking the shelves, he added. "We're decades away from a robot being as fast and dexterous as a human. So ours becomes a symbiotic relationship—we find the problem, the human fixes the problem."

Kristi Branstetter, a Walmart employee in Blue Springs, Mo., said a sense of paranoia has permeated the store following the introduction of a FAST unloader, pickup tower and shelf scanner several months ago.

"People are really worried about losing their jobs because we have this technology," Branstetter said. But the limited capabilities of the automated machines have actually increased her workload, she said. Branstetter said she has not received additional hours of work, and yet she feels more pressure to pick up the slack.

The Blue Springs employees' concerns about looming job loss are symptomatic of national trends. According to U.S. Labor Department data released last month, 49,000 retail jobs have been lost in the past year.

But Branstetter doesn't share her co-workers' concerns about imminent unemployment: "I don't really see where the technology is really beneficial. I just think it kind of adds more work for everybody."