materialhandlingupdate

IN THE EARLY DAYS OF AUTOMATED GUIDED VEHICLES (AGVs), THERE TYPically was just one way the computer-controlled autonomous load carriers could find their way around the manufacturing plants where they initially were used: by following wires embedded in the floor. While revolutionary back then—load carriers could for the first time trundle around a facility without a human operator—that method was simply the first stage of a technological evolution that is not only changing the equipment itself but is also stretching the boundaries of where AGVs can go and how they’re used.

In recent years, the number of navigation methods used by AGVs as they pick up, carry, and drop off their loads in factories, warehouses, and distribution centers has multiplied. But AGV manufacturers aren’t done yet; they continue to tinker with existing guidance technologies and develop new ones. What follows is a brief overview of some of the navigation technologies in use today, along with a preview of what AGV users can expect in the future.

THE TRADITIONALISTS

Wires (also known as inductive guidance) and another early guidance method, magnetic tape, remain popular options, particularly for small and medium-sized operations, in part because they are relatively inexpensive and can offer a quick payback. With wire guidance, a continuous wire path is embedded in the floor. Antennas on the vehicle detect a radio signal from the wire, and encoders on the wheels calculate the distance traveled.

Magnetic tape, which also requires a continuous path, is attached to the floor with an adhesive and may require a protective coating. A sensor on the underside of the vehicle detects the