The struggle of carrying the groceries to the car after a trip to the supermarket could be about to get a lot easier with the help of a self-driving shopping bag.

Car giant Ford is developing an electric-powered cart that can follow shoppers around as they make their purchases and walk back to the car.

The US car manufacturer revealed its plans to take some of the strain out of pulling loads of shopping around in a recent patent application.

Its designs look similar to the traditional two-wheeled trolley bags that have long been towed around by grannies on their trip to the Post Office.

But rather than needing to be tugged behind the user, Ford’s trolley features two different modes.

According to the patent, the handle of the trolley is packed with sensors that detect when it is being pulled, controlling the wheels so that it moves along at the same pace as its owner.

Each of the wheels is powered independently to make cornering easier and on downhill slopes it can apply a braking force to prevent the person using it being knocked over by heavy loads.

“The shopping trolley has an inclination sensor for detecting the inclination of the travel surface,” Ford states in the patent. It also describes how the trolley can deal with steps or kerbs.

Sensors or cameras on the front of the trolley allow it to detect steps and then apply more power to the wheels to make it easier to mount these obstacles.

But while the trolley can be pulled along by the shopper, Ford also wants it to be able to move by itself, following the shopper at an acceptable distance.

Rod Dennis, a spokesman for the RAC, said: “While it might be the promise of autonomous cars that tends to grab the headlines, it’s much more likely that we’ll see smaller-scale smart technology like this.”