Patent attributes
A system may include a vehicle for delivering items and a plurality of racks having a plurality of storage locations. The racks may be arranged to form one or more aisles. The vehicles are configured to drive horizontally along a path that may extend along a path under the racks that is parallel to the aisles. Additionally, the vehicles may be operated to turn while the vehicle is positioned under one of the racks. The vehicles may travel under the racks and cross one or more aisles to reach a particular column in one of the aisles. The vehicle climbs upwardly within the particular column to retrieve an item from a storage location in the column.