A girl walks away from a child in a shopping cart while her family looks through a Walmart store in Secaucus, New Jersey Thomson Reuters Walmart just patented a system based on mini-robots that can control shopping carts, as well as complete a long list of duties once reserved for human employees.

Last week, Walmart was granted a patent for a new system that allows shopping carts to drive themselves, untouched by customers and employees. However, the system goes far beyond self-driving carts, with details on automated devices that can do much of the work a human employees would do.

According to the patent, "motorized transport units" are tools that attach to shopping carts, allowing the carts to drive freely around the store, be summoned to customers, and move safely into docks instead of clogging up parking lots. The system uses a combination of sensors, video cameras, a wireless network, and a central computer.

Shopping carts with the motorized transport units attached at the bottom. US Patent and Trademark Office

But, Walmart's plans are bigger than cleaning up carts more efficiently. These motorized units can also potentially move containers; scan, retrieve, and deliver products; check inventory; retrieve trash; and even connect with customers. And, the patent says that Walmart is not limiting what else the motorized units can be configured to do.

"Walmart was able to revolutionize retail using technology to better serve customers," Walmart spokesperson Lorenzo Lopez told Business Insider. "And as the retail landscape continues to evolve, we want to be able to serve customers when and how they want to shop. That means testing new and innovative ways to serve the customer, which we’ve done through different initiatives like our grocery pickup service."

While the patent describes the motorized unit's role as enhancing a shopping experience and assisting customers or employees, the new tech could be bad news for Walmart employees.

Walmart has come under fire for a number of issues with staffing and employees in recent months.

More than 200 violent crimes have been committed so far this year at Walmart locations across the US, with Bloomberg arguing that the rise in crime is linked to the retailer understaffing stores. Cost-cutting policies that started in the early 2000s resulted in a drop in store quality, while the loss of greeters and the rise of self-checkout scanners made shoplifting and other illegal activities easier to engage in without employees noticing.

The patent's authors argue that the new, tech-heavy system could improve customers' in-store experience and solve problems that Walmart employees cannot.

"In a modern retail store environment, there is a need to improve the customer experience and/or convenience for the customer," reads the patent's background section, which notes issues including insufficient employees in peak hours, under-trained workers due to high-turnover rate, messy aisles, and theft.

"All of these issues can result in low customer satisfaction or reduced convenience to the customer," the patent continues. "With increasing competition from non-traditional shopping mechanisms, such as online shopping provided by e-commerce merchants and alternative store formats, it can be important for 'brick and mortar' retailers to focus on improving the overall customer experience and/or convenience."

Further, the benefits of a more-fully automated store are particularly appealing for retailers as labor costs rise, according to analysts.

While Walmart CEO Doug McMillon announced $2.7 billion in spending on wages and training last year, labor activists argue that the retailer still underpays employees and continue to call for higher pay.

"While it's too early to determine how we would even potentially use this technology, our goal always is to find ways to help simplify processes to help our associates better serve our customers as they will continue to play a critical role in the success of our business," Lopez told Business Insider.

Walmart has not provided any specific information regarding if or when the new system would roll out in stores.

With robots that can drive shopping carts and preform a wide array of other employee duties, Walmart could cut the number of employees on payroll while also improving customer experience. Automation is already taking over the fast-food industry — and it looks like the budget retail business might be next.