BENTONVILLE, ARKANSAS — Walmart has received a patent last week for its self-driving shopping carts system.

According to the US Patent & Trademark Office, the shopping carts will be equipped with detachable motors with video cameras and sensors. Customers can request a cart using a user interface device, potentially a smartphone.

Supermarket employees usually have to round up abandoned carts. With the new system, the carts will be able to return to the docking station automatically. The carts can also be used to restock products that are low in stock.

It is not yet known when or where the new system will be applied in Walmart supermarkets.