STUART is looking for a vehicle for life

Uneven and undulating floors are a well-known challenge in warehouses. Until now, users have had to make the difficult decision between three-wheeled vehicles that are as maneuverable as possible or four-wheeled ones with more stability. The diamondshaped chassis “Stable Transport in Uneven And Rough Terrains,” or “STUART” for short, developed at Fraunhofer IML solves this conflict and is therefore the perfect partner for vehicles that drive in every warehouse.

“The development of the idea and finally the implementation went more smoothly than in almost any other project. With “STUART,” we solved an industry-wide problem quickly and elegantly: Uneven and undulating halls used to be a huge problem for automated guided vehicles. The innovative design of the diamond-shaped chassis eliminates the need for cost-intensive conversion measures, and through a very simple technical principle,” explains Jacob Hamm, research scientist at Fraunhofer IML. 

The diamond-shaped chassis with its centrally positioned differential drive and support wheels at the front and rear provides the perfect grip when things get bumpy. “STUART” is still extremely maneuverable and offers a very narrow envelope. In contrast to conventional four-wheeled chassis, the diamond-shaped chassis never tilts. This is due to its simply constructed joints and levers, which form two contact triangles articulated around the central differential drive axis.

The chassis is currently in use at Fraunhofer IML in a vehicle that weighs only 100 kg and can nevertheless transport up to 400 kg of Euro-pallets. This darts over uneven ground at a speed of 1 m/s and, with a vehicle height of 230 mm, is also equipped for very narrow spaces. However, the principle of the drive can be used for very different applications and in very different vehicles – for heavier or lighter as well as for larger or smaller load carriers.

“STUART” enables automated guided vehicles to keep pace with all types of surfaces, so that no warehouse has to be restructured or renovated. The diamond-shaped chassis also compensates for unevenness so cleverly that it does not need suspension, and the loading area remains unchanged during loading and unloading. There is thus no need to compromise between empty and loaded models here, as is necessary with commercially available vehicles.